The idea of ​​a physical quantity is complete only when it is measured. The need for measuring PV arose at an early stage of understanding nature and increased with the development and complexity of human production and scientific activities. Requirements for the accuracy of PV measurement are constantly increasing.

Measure a physical quantity- means to compare it with a homogeneous value, conventionally accepted as a unit of measurement.

There are two ways to measure an unknown physical quantity:

but) Direct measurement called a measurement in which the value of the PV is determined directly from experience. Direct measurements include, for example, measuring mass with a balance, temperature with a thermometer, length with a scale bar.

b) By indirect measurement called a measurement in which the desired value of the PV is found by direct measurement of other PVs based on the known relationship between them. An indirect measurement is, for example, the determination of the density ρ substances by direct volume measurements V and the masses m body.

Specific implementations of the same PV are called homogeneous quantities. For example, the distance between the pupils of your eyes and the height of the Ostankino tower are concrete realizations of the same PV - length, and therefore they are homogeneous quantities. Cell phone weight and weight nuclear icebreaker are also homogeneous physical quantities.

Homogeneous PVs differ from each other in size. The size of the PV is the quantitative content in this object of a property corresponding to the concept of "physical quantity". The dimensions of homogeneous physical quantities of various objects can be compared with each other.

Let us emphasize the essential difference between physical quantities and units of their measurement. If the measured PV value answers the question “how much?”, then the unit of measurement answers the question “what?”. Some units of measurement can be reproduced in the form of some bodies or samples (weights, rulers, etc.). Such samples are called measures. Measures performed with the highest accuracy currently achievable are called standards.

The value of a physical quantity is an estimate of a physical quantity in the form of a certain number of units accepted for it. The basic units of measurement are arbitrary units of measurement for a few quantities (independent of each other), with which all the others are in a certain connection. should be distinguished true And valid values ​​of a physical quantity.

true value PV is the ideal value of PV, which exists objectively regardless of the person and methods of measuring it. However, the true value of the PV, as a rule, is unknown to us. And it can be known only approximately with a certain accuracy by measurement.

Actual value PV - is the value found experimentally - by measurement. The degree of approximation of the actual value of the PV to the true one depends on the perfection of the technical means of measurement used.

PV measurements are based on various physical phenomena. For example, thermal expansion of bodies is used to measure temperature, gravity is used to measure the mass of bodies by weighing, etc. The set of physical phenomena on which measurements are based is called measuring principle .

Measuring instruments include measures, measuring instruments, etc.

Measuring device is a measuring instrument designed to generate a signal measurement information in a form that can be directly perceived by a person. Measuring instruments include ammeter, dynamometer, ruler, scales, pressure gauge, etc.

In addition to the basic physical quantities in physics, there are derivative physical quantities that can be expressed through the main ones. To do this, it is necessary to introduce two concepts: the dimension of the derived quantity and the defining equation. Derived units are obtained from the main ones with the help of the equations of connection between the corresponding quantities.

Sensitivity of measuring instruments – Measuring instruments are characterized by sensitivity. The sensitivity of the measuring device is equal to the ratio of the linear (Dl) or angular (Da) movement of the signal indicator on the instrument scale to the change DX of the measured value X that caused it. Sensitivity determines the minimum measured value of the FV using this device.

The task of a physical experiment is to establish and study the relationships between various physical quantities. In this case, in the course of the experiment, it is often necessary to measure these physical quantities. To measure a physical quantity means to compare it with an identical physical quantity taken as a unit.

Measurement is the experimental determination of the value of a physical quantity using measuring instruments. Measuring instruments include: 1) measures (weights, measuring cups, etc.); 2) measuring instruments with a scale or a digital display (stopwatches, ammeters, voltmeters, etc.); 3) measuring and computing complexes, including measuring instruments and computer technology.

To measure a physical quantity, you must: 1) select the unit of measurement for this quantity; 2) select measuring instruments graduated in established units with the required accuracy; 3) choose the most appropriate measurement technique; 4) to carry out with the help of available means the measurement of a given value; 5) give an estimate of the error made during the measurements.

Depending on the method of obtaining the measurement result, they are divided into straight And indirect. Direct measurements are carried out using measuring instruments that directly determine the value under study (for example, measuring length using a ruler, body weight using scales, time using a stopwatch). However, direct measurements are not always feasible, convenient, or have the necessary accuracy and reliability. In these cases, use indirect measurements in which the desired value of a quantity is found from a known relationship between this quantity and quantities whose values ​​can be found by direct measurements. For example, the volume can be calculated from the measured linear dimensions of the object, the mass of the body - from the known density and volume, etc. Thus, the value of any quantity can be obtained both by direct measurements and by indirect ones. For example, the resistance value of a wire can be determined both with the help of an ohmmeter, and with the help of calculations based on the measured values ​​of the current flowing through the conductor and the voltage drop across it. The choice of a method for measuring a physical quantity for each specific case is decided separately, taking into account the convenience, speed of obtaining the result, the necessary accuracy and reliability.

Each physical experiment consists of preparing the object under study and measuring instruments, observing the course of the experiment and instrument readings, recording readings and measurement results.

Measuring device called a device that allows you to directly determine the values ​​of the measured quantity.

Each measuring device has a reading device for displaying information about the results of measurements. The simplest reading device consists of a scale and a pointer.

Scale is a collection of marks applied across a certain line. The intervals between the marks are called scale divisions. For ease of reference, individual marks are isolated, increasing their length or thickness, and marked with numbers.

Pointer is performed in the form of an arrow or a stroke that can move along the scale. In some devices, a light spot containing an image of a stroke moves along the scale.

There are devices with digital indication, in which information about the measured value is given in the form of a number displayed by means of a special display.

For each instrument, it is possible to allocate an interval of the measured value, within which it can operate safely and give reliable results. This interval is called operating range of measurements. If the value to be determined is less than lower limit working range, then the measurement result will be too rough or the reading of the device cannot be distinguished from zero at all. If the measured value exceeds upper limit, the device may be damaged.

Sensitivity Measuring instrument characterizes its ability to respond to small changes in the measured value. The sensitivity  is determined by the formula:

 \u003d S / x,

where S is the movement of the pointer of the reading device when the measured value changes by x.

If the sensitivity remains constant over the entire operating range, then the same changes in the value of x both at the beginning of the scale and at its end correspond to the same movements of the pointer S. In this case, the device has scale with the same divisions called uniform. If the sensitivity of the device is not constant, then in different parts of the range, equal changes in the measured value correspond to unequal movements of the pointer. The scales in these cases are uneven.

The price of division of the scale FROM X called the change in the measured value, which causes the pointer to move one division. Moving the pointer by n such divisions indicates that the measured value has changed by x = nС Х.

this implies division rule: the difference in the values ​​of the measured value x, which corresponds to the nearest digitized marks, should be divided by the number of divisions n between these marks, that is

C X \u003d x / n.

For example, the numbers 7 and 8 on the student ruler correspond to distances of 7 cm and 8 cm from its origin. The difference between these distances x = 8 cm –7cm = 1 cm = 10 mm. The number of divisions between the indicated marks is n = 10. Therefore,

C X \u003d x / n \u003d 10 mm / 10 \u003d 1 mm.

There are devices with non-uniform scales, in which the price of divisions changes when moving from one section of the scale to another. As an example, Figure 1 shows an ohmmeter scale. The division price in the area up to 0.5 ohms is 0.05 ohms, in the area from 0.5 ohms to 2 ohms it is 0.1 ohms. Determine the price of divisions in the remaining sections yourself and read the reading of the ohmmeter shown in Fig. one.

At countdown instruments, it is necessary to determine the price of divisions of the instrument in the place of the scale where the pointer is located.

With a correct reading, the line of sight should be perpendicular to the plane of the scale. To ensure this condition, electrical measuring instruments are equipped with a mirror scale. The line of sight is perpendicular to the scale if the stroke of the reading device coincides with its image in the mirror.

The sequence of placement of devices and their connection with each other should be such as to ensure maximum accuracy and convenience of the experiment. At the same time, setting their zero values ​​​​on a scale or digital display is of paramount importance for obtaining an accurate result. Work on defective devices is not allowed! Any malfunction of the devices should be reported to the teacher or laboratory assistant immediately! Before turning on the devices, you must make sure that they are connected correctly and obtain permission to turn them on from the teacher.

Observations of instrument readings should be carried out so that the scale or display of the instrument is clearly visible.

The form of recording experimental results should be clear and compact. To do this, use the tables given in the guidelines for each laboratory work, and it is in these tables, copied by students on the work form, that the results should be recorded taking into account the units of measurement and the unit division value. In this case, if the required accuracy of the result is not set in advance, then one should try to record the measurement result with the highest possible accuracy that the device gives (i.e., write down the maximum possible number of significant digits). To reduce the number of zeros in the obtained values ​​of the measured value (those zeros that are not significant figures), it is convenient to indicate the decimal multiplier 10 n for the entire row or column of the table. For example, it is necessary to record the values ​​​​of the density of bodies (in kg / m 3) with an accuracy of two significant figures. In order not to write extra zeros, for the entire row (or column) of the table in which the values ​​of the density of bodies are entered, a multiplier 10 3 is placed before the unit of measurement. Then for the density of water in the corresponding cell of the table, instead of 1000, there will be 1.0. We note, however, that one should not, at all costs, achieve greater accuracy in measurements than is necessary in the task at hand. For example, if you want to know the length of the boards prepared for the production of containers, then you do not need to measure with an accuracy of, say, a micron. Or, if when making indirect measurements, the value of any of the measured quantities is limited by some accuracy (expressed in a certain number of significant figures), then it makes no sense to try to measure other quantities with much greater accuracy than this.

Physical quantities. Measurement of physical quantities.

The purpose of the lesson: To introduce students to the concept of "physical quantity", the basic units of physical quantities in SI, to teach how to measure physical quantities using the simplest measuring instruments, to determine the measurement error.
Tasks:

Educational: to acquaint students with the concept of a physical quantity, the essence of determining a physical quantity, with the concept of measurement error, the basic units of physical quantities in SI; to teach how to determine the division value of a measuring instrument, determine the measurement error, convert values ​​from basic to submultiples and multiples

Developing: to expand the horizons of students, develop their creative abilities, instill interest in the study of physics, taking into account their psychological characteristics. Develop logical thinking through the formation of concepts: the division price (methods and methods of its application), the scale of the measuring instrument.

Educational: to form the cognitive interest of students through historical and modern information about the measurement of physical quantities; to teach the culture of communication of students, partnership, work in groups.

Equipment: computer, projector, laboratory, demonstration and household measuring instruments (thermometer, ruler, tape measure, scales, clock, stopwatch, beaker, other measuring instruments).

During the classes:

Updating of basic knowledge

Explanation of new material I (slide 4 - 10)

Practical task I.

measure the dimensions of your textbook. Calculate the area of ​​its cover. Calculate the volume of the textbook.

Explanation of new material II (slide 11-13)

What do all devices have in common? Answer: scale Characteristics of any scale: limits of measurement and division value. Let's find out what it is. The measurement limits are determined by the numbers at the first and last division of the scale. Do not use the device when trying to measure a value that exceeds the limit of its measurement! The division price is the numerical value of the measured value, which corresponds to one (smallest) division of the scale
5. Practical task II (slide 14) Determine the price of division of your line and devices on the demonstration table and screen.

Practical task III. (slide 15)

Summarizing. Announcement of work in the next lesson - we will measure the volumes of liquids (taking into account errors!).

by measurement refers to the set of actions performed by special means, in order to find the numerical values ​​of the measured quantity in the accepted units of measurement.

The purpose of the measurement is to obtain the value of a physical quantity characterizing the controlled object. There are many types of measurements (Figure 1.1).

With the help of measurement, the measured value is compared with. unit of measurement, i.e. if there is some physical quantity X, and the unit of measurement accepted for it is W, then the value of the physical quantity is defined as

where q is the numerical value of the physical quantity in the accepted units of measurement.

This equation is called the main measurement equation.

For example, one volt is taken as a unit of voltage U of an electric current. Then the voltage value of the electrical network is U = q [U] = 220 = 220 V, i.e. the numerical value of the voltage is 220.

If one kilovolt is taken as a unit of voltage U, and 1 V \u003d 10 kV, then U \u003d q [U] \u003d 220 \u003d 0.22 kV. The numerical value of the voltage will be 0.22.

Another important concept is measuring conversion, which is understood as the establishment of a one-to-one correspondence between the sizes of two quantities: the converted (input) and the one transformed as a result of the measurement (output).

The set of dimensions of the input value, which is converted using a technical device, is called range of transformations.

Depending on the types of physical quantities, measuring transformations are divided into three groups.

First group represents quantities that determine the relationship: "weaker - stronger", "softer - harder", "colder - warmer", etc. Such a value is, for example, wind speed. They are called order relations or equivalence relations.

Co. second group include quantities for which order relations are determined not only between the values ​​of the quantities, but also their range, i.e., the difference in the values ​​of the extreme quantities. For example, the temperature range difference from plus 5 up to plus 10 "C and the difference in the temperature range from plus 20 to plus 25 "C are equal. In this case, the ratio of the order of magnitude plus 25 "C is warmer than plus 10" C, and the ratio of the order of magnitude of the difference in the extreme values ​​of the first values ​​corresponds to the difference in the extreme values ​​of the second values. In both cases, the order relation is uniquely determined by means of a measuring transducer, such as a liquid thermometer, and the temperature can be assigned to measuring transformations.

Third group characterized by the fact that it is possible to perform operations similar to addition and subtraction with values ​​(active property). For example, such a physical quantity as mass: two objects each weighing 0 5 kg, placed on one bowl balance scales, on the other bowl are balanced by a weight of 1 kg.

The measured value can be independent, dependent And external.

Independent variable changes only under the action of the contractor (for example, the opening angle of the carburetor throttle when testing the engine).

Dependent value - this is the value that changes when the independent variables change (for example, the speed of the car when the carburetor throttle opening angle changes).

External value - is a measure of the influence external factors on the results of measurements when performing measurement work, but not controlled by the person performing these measurements (for example, headwind speed when determining the speed of a car).

The standard unit of magnitude called a measuring instrument designed to reproduce and (or) store a unit of quantity and transfer its size to other measuring instruments of a given quantity.

Physical quantities

Physical quantities are divided into geometric, kinematic, dynamic, etc.

K geometrically quantities include linear size, volume, angle.

Kinematic Quantities include speed, acceleration, rotational speed.

TO dynamic - mass, consumption of any substance, pressure, etc.

To other values can include time, temperature, color illumination.

Technological process- the main part of the production (production process).

The technological process consists of a number of production operations that are performed in a strictly defined sequence. A production operation is a part of the technological process performed at a specific workplace with a specific tool or on specific equipment.

Operations follow in the technological process in a strictly established order. For example, marking is followed by cutting boards into blanks for parts, then planing, trimming, making tenons, gouging nests, etc. No one will file tenons on unplaned parts or grind a part before it is given the final shape by planing.

The degree of operational dissection of the technological process depends on the amount of work for the manufacture of this product, on the number of workers involved in the manufacture of the product, on the size of the production facility (working area), on the nature of the workplace equipment and other production conditions. The deepest division of the technological process into operations should be considered when each operation is performed in one step without changing the tool. The smaller the operation, the easier and more accessible it is to perform. Therefore, the deeper the operational division of the technological process, the higher labor productivity and the less need for highly skilled workers.

The technological process can be general for the manufacture of the entire product or cover, for example, only the processing of parts, only the assembly operations or the operations of finishing products.

The technological process should not be confused with the production technology. Under the production technology, one must understand not only the sequence of operations performed, but also the methods and methods for performing these operations. Production technology should be based on the latest achievements of science and technology, taking into account the experience of innovators and innovators.

The place in production where any production operation is performed is called a workplace. Machine tools, mechanisms, stationary devices installed at the workplace, i.e. permanent devices, fixed motionless, constitute the equipment of the workplace.

From how the workplace is organized, from the provision of its tools and fixtures, from the location of materials, tools and fixtures relative to the permanent equipment of the workplace and relative to the worker himself, from the preparedness of equipment, tools and materials for work, from the quality of care for the workplace and equipment - the productivity and quality of products depend on all this.

In carpentry, as elsewhere in industry, the technological process is subdivided according to the division of production into workshops. The main workshops are cutting, drying, machine, gluing, assembly and finishing. Next are auxiliary and service shops. A service shop is, for example, a mechanical (metalworking) workshop with a saw and knife workshop. Within the workshop, the technological process is divided into processing stages. For example, the process steps in assembly shop- this is the assembly of units, the assembly of combines, the cleaning and processing of the assembled elements, the assembly of the entire product. Stages of the technological process in the finishing shop: finishing preparation, initial and intermediate finishing, drying, final finishing.

The division of the technological process according to the workshops allows:

1) it is most rational to equip each workshop with machine tools, mechanisms, devices, according to the nature of the work performed in it;
2) create in the workshop best conditions labor, taking into account the peculiarities of work in it;
3) adapt the premises and equipment of the workshop to perform work in accordance with the requirements of safety, labor protection and fire protection for these types of work;
4) to manage the work of the shop most efficiently and skillfully, to exercise fuller quality control over the work;
5) rationally organize jobs.

The division of the technological process into processing stages allows:

1) place machines, mechanisms and other equipment in the best production sequence, ensure mechanized supply of materials to them;
2) organize work in teams and units.

Technological process of production

The production process is a set of all the actions of people and tools necessary for a given enterprise to manufacture products.

The production process consists of the following processes:

The main ones are technological processes during which changes in the geometric shapes, sizes and physical and chemical properties of products occur;
- auxiliary - these are processes that ensure the uninterrupted flow of the main processes (manufacturing and repair of tools and equipment; repair of equipment; provision of all types of energy (electricity, heat, steam, water, compressed air, etc.));
- service - these are processes associated with the maintenance of both main and auxiliary processes and do not create products (storage, transportation, technical control, etc.).

In the conditions of automated, automatic and flexible integrated production, auxiliary and service processes are more or less combined with the main ones and become an integral part of the production processes, which will be discussed in more detail later.

Technological processes, in turn, are divided into phases.

Phase - a set of works, the performance of which characterizes the completion of a certain part of the technological process and is associated with the transition of the object of labor from one qualitative state to another.

In mechanical engineering and instrumentation, technological processes are mainly divided into three phases:

Procurement;
- processing;
- assembly.

The technological process consists of technological actions, operations, sequentially performed on the given object of labor.

An operation is a part of a technological process performed at one workplace (machine, stand, unit, etc.), consisting of a series of actions on each subject of labor or a group of jointly processed items.

Operations that do not lead to a change in the geometric shapes, sizes, physical and chemical properties of objects of labor do not belong to technological operations (transport, loading and unloading, control, testing, picking, etc.).

Operations also differ depending on the means of labor used:

Manual, performed without the use of machines, mechanisms and mechanized tools;
- machine-manual - performed using machines or hand tools with the continuous participation of the worker;
- machine - performed on machines, installations, units with limited participation of the worker (for example, installation, fixing, starting and stopping the machine, unfastening and removing the part). The machine does the rest;
- automated - are performed on automatic equipment or automatic lines.

Hardware processes are characterized by the performance of machine and automatic operations in special units (furnaces, installations, baths, etc.).

Automation of technological processes

production time“eats up” a huge part of the time of a unique human life, cuts off opportunities for the free development of individuality, deprives a person of the fullness of perception of the surrounding world.

Unfortunately, the radical release of people from the sphere of material production is still far away. At the same time, global engineering and technological ideas are emerging that, to one degree or another, pave the way for the implementation of “unmanned” production. Among such ideas, one of the most promising is the idea of ​​flexible automated production.

Flexible automated production (FLP) allows the transition from the production of one product to another with virtually no readjustment of technological and any other equipment; if in some cases a changeover is required, then it is carried out simultaneously with the release of the previous product. Flexible manufacturing consists of flexible manufacturing systems (FMS), which are characterized by a more complete processing of parts in one workplace.

In modern and promising production, the “man-machine” system becomes decisive. The man at the remote control is a typical module of any production environment which requires significant psychological stress from the worker. Techniques and technologies are constantly becoming more complex, moreover, to a certain extent, the production environment becomes hostile to humans. There is a need to green the production environment, protect the psyche of a working person, reduce their energy costs. The solution of these problems was taken over by engineering psychology.

“Today computers do everything!” - this common phrase, of course, does not mean that a computer cooks soup, manufactures a car body, assembles a video recorder, publishes a book or magazine. However, he manages the technique, industrial equipment and automation tools that already directly do the things we need.

Thus, technological processes are automated on the basis of a computer. Thanks to this, a person is freed from direct participation in production operations. The functions that he performed before are performed by machines in modern production. Physical labor is being phased out. The role of a person today is control, adjustment of equipment, production management by means of a computer - mainly mental work. Man cannot be replaced by automatic machines only where his intuition, experience, and creativity are needed.

Process development

Each manufacturing enterprise has developed and operates the main or permanent production process or processes. They are approved by the chief technologist of the enterprise. For greater clarity, the description of the technological process is accompanied by a flow diagram, which also goes through all stages of coordination.

The development of a technological process for a newly commissioned production is carried out on the basis of standard manufacturing processes, taking into account automation. When mastering new types of products or new technologies, temporary TPs are used.

Documents of technological processes

Technological documents used to describe and implement the TP of production depend on the industry in which a particular enterprise operates. If in most industrial areas route maps are taken as the basis, then in the machine tool industry, operational maps are the same integral part of technological documentation as route maps.

The development of the technological process and the preparation of technological documentation is carried out in full compliance with the requirements of GOST 14.301 - 83, which is part of the Unified System for Technological Documentation (ESTD). In accordance with the provisions existing in the ESTD, technological documents for the most part refer to specialized documentation. While Technological Instructions are classified as common documents.

The standard provides for the following special technological documents:

A route map is used for a route or route-operational description of the TP or for listing technological operations and movements in the production process. Contains data on equipment, material standards and labor costs, technological equipment;
a technological process map or a map for the operation being performed. It is intended to describe a specific manufacturing or repair operation. It also contains all the information necessary for the execution of the technological process;
a map of a typical technological process or a map of a group technological process that is used for the corresponding TP;
a repair process map is used to develop a repair process, and it is linked to product defects;
an operational map used to describe a specific technological operation, indicating the transitions within it;
a list of technological documents, which contains a complete set of documents used for production at the enterprise;
other technological documents.

Process development

Usually done before construction starts. production shops. Because, if we are talking about large production facilities, they are designed and built taking into account the equipment and technologies used. The future automation of technological processes is also taken into account.

The flow diagram in this case is a necessary document for designers.

Process design depends on the type of product or job, the industry sector and the annual output.

Depending on the last indicator of production, they are divided into types:

small-batch;
serial;
mass.

At the same time, the technological process of production can be classified in accordance with GOST as:

A typical TP is developed at the federal or industry level as a model for the development of production technological documents at industry enterprises;
prospective TP takes into account the use of the latest methods and methods of the technological process;
group technological process;
route technological process is developed for single or small-scale production. The development of the technological process in this case consists in the development of a route map without taking into account transitions;
the operational technological process is developed for high-volume and mass production. In addition to the route map, operational maps are being developed. And the route map itself is a list of operations specified in the sequence of execution of the technological process;
route-operational TP allows you to include a description of some operations in the route map;
a single technological process is developed for small-scale production. Such technological manufacturing processes are characterized by minimization of preparatory operations. The development of the technological process is aimed at the effective use technological equipment.

Process control

Each technological process in the general production cycle has its own purpose, in accordance with which certain requirements are imposed on it - ensuring a given or maximum productivity, a given or best product quality, given or minimal cost raw materials (semi-finished products) and energy per unit of finished product, etc.

Fulfillment of the requirements for the technological process is possible only with a targeted impact on its technological regime.

Any technological process is subject to the action of various factors, random in nature, which cannot be foreseen in advance. Such factors are called perturbations. These include, for example, random changes in the composition of raw materials, coolant temperature, characteristics of technological equipment, etc. Disturbing effects on the technological process cause changes in the technological regime, which, in turn, leads to a change in such technical and economic indicators of the process as productivity, quality products, consumption of raw materials and energy, etc. Therefore, to ensure the specified (required) technical and economic indicators, it is necessary to compensate for fluctuations in the technological regime caused by the action of disturbances.

Such a purposeful impact on the technological process is a process of management. The set of requirements implemented in the management process is called the goal of management. Finally, the controlled technological process itself, together with the technological equipment in which it takes place, is the object of control.

The control object and the devices necessary for the implementation of the control process are called the control system.

Technological process of repair

Operation - a part of the technological process of repair, performed continuously at one workplace, with a certain type of equipment, by workers of the same profession. The operation usually bears the name of the equipment with which the operation is performed. For example, an assembly operation is performed in an assembly shop using assembly equipment by a fitter, etc.

Installation - part of the operation performed on the product when changing its position relative to the equipment, tool. For example, the assembly operation of a car consists of installing the engine, gearbox, etc.

Transition - part of the operation, installation, performed on one section of the product, with one tool operating in the same mode. For example, the engine installation consists of several transitions: engine slinging; lift, move, put the engine on the frame; fasten the engine to the frame.

A passage is one of several transitions that follow each other. For example, the transition - slinging the engine consists of two passes - linking one sling on the engine on one side and securing the other end on the crane hook; the same, but with the second line and on the other side of the engine.

Working technique - part of the transition or passage, which is a complete cycle of working movements. For example, fastening one end of the sling to the engine on one side is one method, fastening the other end of the sling to the crane hook is another working method.

The working movement is the smallest moment of the operation. For example, to take a detail is a working movement.

The development of the technological process consists in the fact that for each of its elements a description of the content of the work, the necessary equipment, fixtures and tools, the complexity of the work and labor costs are established. All these data are entered into technological cards. Depending on the volume of work performed, a different depth of development of the technical process is established. For small enterprises with a small amount of work, the technical process is developed at the level of operations and installations using universal equipment and tools. The technological map indicates only the order of operations (route technological map). Works are carried out by highly qualified workers.

For service stations with a sufficiently large amount of work, the development of a technological process is carried out at the level of transitions and passages, indicating the content of work for each operation. Works are performed on special equipment (stands) using special devices and tools according to operating procedures. technological maps.

Process development is carried out separately for Maintenance TO-1, TO-2 and for repair work on current and major repairs.

The largest volume of work performed takes place during the overhaul of cars, which is carried out at specialized car repair plants.

Cars accepted for repair undergo an external washing and go to the dismantling operation. All units are removed from the car frame, the base part, they are cleaned of dirt, oil, disassembled into components and parts. Removed parts are sorted into fit, unusable and in need of repair. Suitable parts are re-assembled, unusable parts are sent for scrap, parts that require repair are restored and sent for assembly of units. The nodes are assembled into units, the units are again installed on the car frame. The assembled car is tested and handed over to the customer.

It is important to note that the development of the technological process for conducting current repair with the peculiarity that in this case the number is smaller and they are performed in a smaller volume.

Technological process of processing

An operation is a completed part of the technological process of processing one or more simultaneously processed workpieces, performed at one workplace by one worker or team. The operation begins from the moment the workpiece is installed on the machine and includes all its subsequent processing and removal of the machine. The operation is the main element in the development, planning and regulation of the technological process of processing workpieces. The operation is performed in one or more settings of the workpiece.

Installation - a part of the technological operation, performed with the constant fixing of the workpieces being processed. In the installation, separate positions of the workpiece are distinguished.

Position - a fixed position occupied by a fixed workpiece together with a fixture relative to a tool or a fixed piece of equipment to perform a certain part of an operation.

A technological operation can be performed in one or several transitions. The transition is the part of the operation, which is characterized by the constancy of the cutting tool, the processing mode and the surface to be machined. In turn, the transition can be subdivided into smaller elements of the technological process - passages. During the pass, a layer of material is removed without changing the machine settings.

The development of all these elements of the technological process largely depends on the nature of the workpiece and the allowances for its processing.

A workpiece is an object of production from which a part is made by changing the shape, size, roughness and properties of the material. Blanks are produced in foundries (castings), forging shops (forgings, stampings) or blanking shops (cut from rolled products). The method of producing blanks depends on the design requirements for the parts, material properties, etc.

When developing a technological process, it is very important to choose the right technological (installation and measuring) bases.

Under the mounting base is understood the surface of the workpiece on which it is fixed and on which it is oriented relative to the machine and the cutting tool. The mounting base used in the first operation is called the roughing base, and the base that was formed as a result of initial processing and is used to fix and orient the workpiece during further processing is called the finishing base.

Measuring bases are the surfaces of the workpiece, from which the dimensions are measured when monitoring the results of processing.

When choosing technological bases, they are guided by the rules of unity and constancy of bases. According to the first rule, the same surfaces should be used as installation and measuring bases whenever possible. The second rule requires that as many surfaces as possible be processed from one base. Compliance with these rules ensures higher processing accuracy. For a rough installation base, they usually take the surface that is not subject to further processing or has the smallest allowance for processing. This avoids marriage due to insufficient allowance for this surface. The surfaces selected as mounting bases must allow the workpiece to be securely fastened.

The development of the technological process begins with the analysis of the initial data - the working drawing and the dimensions of the batch of parts (the number of workpieces of the same name to be processed). At the same time, the availability of equipment, fixtures, etc. is taken into account.

Based on the working drawing and batch sizes, the type and dimensions of the workpiece are determined. So, for a single production, workpieces are usually cut from high-quality or sheet metal(in this case, the locksmith must determine the dimensions of the workpiece, taking into account the processing allowances). In serial and mass production, blanks are usually obtained by casting, free forging or stamping.

For the selected workpiece, technological bases are outlined: first - roughing, then - the base for finishing.

Based on typical technological processes, the sequence and content of technological operations for processing a particular part are determined. When the sequence of processing is determined and the operations are planned, for each of them the necessary equipment, technological equipment (working and measuring tools, fixtures) and auxiliary materials (means for painting workpieces during marking, cooling and lubricants, etc.) are selected.

In the case of processing parts on machine tools, processing modes are calculated and assigned. Then the technological process is normalized, i.e., the time limit for the execution of each technological operation is determined.

established by state standards one system technological preparation of production (ESTPP). The main purpose of the ECTPP is to establish a system for organizing and managing the process of technological preparation of production. ECTPP provides for the widespread use of progressive standard technological processes, standard technological equipment and means of mechanization and automation of production processes.

Main technological processes

The technological process is part of the production process. The technological process is the basis of any production process, is its most important part associated with the processing of raw materials, the processing of blanks, semi-finished products and their transformation into finished products. The main part of the technological process is the technological operation. An operation is a completed part of the technological process, performed at one workplace and characterized by the constancy of the object of labor, tools of labor and the method of influencing the object of labor. Operation examples; drilling holes, turning a cylindrical surface on a lathe, threading, heating the workpiece before stamping, etc.

Almost any specific technological process can be considered as part of a more complex process and a set of less complex technological processes. Any technological process for the manufacture of finished products (car, refrigerator, electric motor) can be divided into simpler technological processes (technological processes for the manufacture of blanks, forgings, castings, stampings, their machining, hardening, painting, etc.). In turn, simple technological processes can be divided into elementary ones. An elementary technological process is the simplest process, further simplification of which leads to the loss of the characteristic features of the technological process. production area The national economy is characterized by division into branches.

Industry - a set of industrial and manufacturing enterprises, research and design organizations that manufacture products that are similar in purpose and raw materials, use similar technology in the main production, and use specially trained personnel for its production. Each industry has its own specific features of production, organization and economy.

The basis of the production of any product is raw materials - the material or object of labor, for the extraction or production of which labor was expended. Raw materials are classified into natural and artificial. Natural raw materials are extracted from the bowels of the earth, plants, animals, and are divided into organic (oil, wood, flax, cotton, etc.) and mineral (chalk, iron ore, salt, alumina, etc.). Artificial raw materials are obtained as a result of processing natural raw materials (acids, plastics, chemical fibers, synthetic rubbers, etc.). Artificial raw materials, like natural ones, are divided into organic (viscose, acetate fibers, etc.) and mineral (silicate, metal fibers, etc.).

The basis of the activity of each enterprise is the production process. The production process is a set of all the actions of people and tools of production necessary for a given enterprise for the manufacture or repair of manufactured products. It can contain many technological processes and includes: production preparation; receipt, transportation, control and storage of materials (raw materials, semi-finished products); technological processes for the manufacture of blanks, parts, assemblies and assemblies; production and repair of technological equipment, maintenance and repair of equipment, technological processes of waste disposal and much more. Technological processes are divided into main, auxiliary and service.

Trade and technological process

Trade and technological process in retail is a complex of interrelated trade /commercial/ and technological operations and is the final stage of the entire trade and technological process of commodity circulation.

The structure of the trade and technological process, the sequence of various operations depends on the degree of economic independence commercial enterprise, the method used to sell goods, the type and size of the store and other factors.

In stores selling non-food products, there are three main schemes of the technological process of sale.

The first includes the acceptance of goods and their supply directly from the receiving area to shopping room for sale. Such a scheme can be used when using containers-equipment in the trade and technological process. The use of this scheme of the technological process makes it necessary to allocate two functional premises for its implementation: for the acceptance of goods and for their sale.

In the second scheme, the technological process consists of three operations: acceptance, storage of goods and their sale.

The most complex is the third scheme of the technological process, which is used when organizing the sale of goods that require preliminary refinement before serving them on the trading floor (for example, release from factory packaging, ironing, cleaning, etc.). Its use requires the presence of another functional room - a room for preparing goods for sale. In most cases, non-food stores use all three process flow diagrams.

An integral part of any technological process in trade is direct customer service, which is one of its main functions.

The constituent elements of the process of selling goods in non-food stores are divided into:

Basic.

These include:

A) the offer of goods;
b) consultations of buyers;
c) operations for the release of goods;
d) settlement and cash operations.

Auxiliary.

These include:

A) acceptance of goods;
b) placing and stacking them in a warehouse;
c) preparation of goods, workplaces and customer service areas for sale;
d) internal transportation of goods.

Technological process of production

The combination of useful properties of culinary products is characterized by nutritional value, organoleptic characteristics, digestibility, safety.

Energy value - is characterized by the amount of energy released from food substances in the process of biological oxidation.

Biological value - is determined mainly by the quality of food proteins - digestibility and the degree of balance of the amino acid composition.

Physiological value - the presence of substances that have an active effect on the human body (caffeine, coffee).

Organoleptic indicators (appearance, color, texture, smell, taste) are determined with the help of the sense organs.

Digestibility - the degree to which food components are used by the human body.

Safety is the absence of an unacceptable risk associated with the possibility of harm to human health.

There are the following types of food safety:

Chemical safety is the absence of an unacceptable risk that can be caused by toxic substances to the life and health of consumers.

Toxic substances are nitrates, nitrites, pesticides, antibiotics, dyes and prohibited food additives.

Sanitary and hygienic safety - the absence of an unacceptable risk that may arise from microbiological and biological contamination of culinary products.

At the same time, toxic substances (salmonella, staphylococcus) accumulate in the products, which cause poisoning of varying severity.

Radiation safety is the absence of an unacceptable risk that can be caused to life and health by radioactive substances.

Process steps

Single technological process - A technological process for the manufacture or repair of a product of the same name, size and design, regardless of the type of production Standard technological process - A technological process for the manufacture of a group of products with common design and technological features.

Group technological process - The technological process of manufacturing a group of products with different design, but common technological features.

A technological operation is a complete part of a technological process performed at one workplace.

On the basis of operations, the complexity of manufacturing products is determined and time standards and prices are established; the required number of workers, equipment, fixtures and tools is set; the cost of processing is determined; scheduling of production is carried out and quality control and timing of work is carried out. In addition to technological operations, the technological process in some cases includes auxiliary operations (transport, control, marking, chip removal, etc.) that do not change the size, shape, appearance or properties of the workpiece, but are necessary for the implementation of technological operations.

A technological transition is a completed part of a technological operation performed on one or more surfaces of the workpiece, with one or more simultaneously working tools without changing or with automatic change in the operating modes of the machine. In the case of using conventional metal-cutting machine tools, technological transitions, as a rule, are carried out with unchanged modes of their operation. Elementary transition - part of the technological transition, performed by one tool, over one area of ​​the surface of the workpiece being machined, in one working move without changing the mode of operation of the machine.

Auxiliary transition - a completed part of a technological operation, consisting of human and (or) equipment actions that are not accompanied by a change in the shape, size and surface roughness of the object of labor, but are necessary to perform a technological transition (setting a workpiece, changing a tool, etc.).

Billet - intermediate product metallurgical production, from which the part is made by changing the shape, dimensions, surface properties and (or) material. Initial workpiece - Workpiece before the first technological operation.

A part is a product made of a material that is homogeneous in name and grade without the use of assembly operations (for example, a shaft from a homogeneous piece of metal, a cast body, etc.).

Process safety

Technological process, techniques, modes of operation and maintenance of production equipment;
- industrial premises; and sites;
- raw materials, blanks and semi-finished products, as well as methods for their storage and transportation (including finished products and production waste);
- production equipment and its placement, as well as the distribution of functions between a person and equipment in order to limit the severity of labor, etc.

Production processes should not pose a danger to the environment, they should be fire and explosion-proof. All these requirements are laid down during their design and implemented at the stages of organizing and conducting technological processes.

In doing so, it is necessary to provide for the following:

Elimination of direct contact of workers with raw materials, blanks, semi-finished products, finished products and production wastes that have a harmful effect;
- replacement of technological processes and operations associated with the occurrence of hazardous and harmful production factors, processes and operations in which these factors are absent or have a lower intensity;
- replacement of harmful and flammable substances with less harmful and dangerous ones;
- comprehensive mechanization, automation, the use of remote control of technological processes and operations in the presence of dangerous and harmful production factors;
- sealing equipment;
- the use of control and process control systems that ensure the protection of workers and emergency shutdown of production equipment;
- timely receipt of information about the occurrence of hazardous and harmful production factors;
- use of means of collective protection of workers;
- rational organization work and rest in order to prevent monotony and physical inactivity, as well as limit the severity of work.

Safety requirements for the technological process are included in the regulatory and technical and technological documentation.

Despite the wide variety of technological equipment in terms of purpose, design and operation features, it is subject to General requirements safety, formulated in GOST 12.2.003. In accordance with GOST, production equipment must ensure safety during installation, operation, repair, transportation and storage, when used separately or as part of complexes and technological systems.

The equipment is placed in compliance with the current technological, construction, sanitary, fire and other requirements. The convenience and safety of its maintenance, the safety of evacuation of workers in the event of emergencies should be ensured, and the impact of hazardous and harmful production factors should be excluded. Passage width. When the equipment is located with the back sides to each other, it should be at least 1 m, when the front and back sides are located to each other - at least 1.5 m, when the workplaces are located opposite each other - at least 3 m. Workplace organized taking into account ergonomic requirements in accordance with GOST 12:2.061.

Production equipment in operation:

Must not pollute environment emissions of harmful substances above the established norms;
- must be fire and explosion proof;
- must not create a hazard as a result of exposure to humidity, solar radiation, mechanical vibrations, high and low pressures and temperatures, aggressive substances and other factors.

Safety requirements are imposed on the equipment during its entire service life.

The safety of production equipment itself must be ensured by the following measures:

The correct choice of operating principles, design schemes, safe structural elements, materials, etc.;
- application in the design of mechanization, automation and remote control;
- the use of special protective equipment in the design;
- fulfillment of ergonomic requirements;
- inclusion of safety requirements in technical documentation for installation, operation, repair, transportation and storage.

In accordance with the requirements of the SSBT, safety requirements standards are being developed for all major groups of production equipment. Consider the sections that they include.

Safety requirements for the main structural elements and the control system, due to the features of the purpose, design and operation of this group of production equipment and its components:

Prevention or limitation of the possible impact of hazardous and harmful production factors to regulated levels;
- elimination of causes contributing to the emergence of dangerous and harmful production factors;
- arrangement of controls and other requirements.

The standards for individual groups of production equipment indicate:

Moving, current-carrying and other dangerous parts to be protected;
- permissible values ​​of noise characteristics and vibration indicators, methods for their determination and means of protection against them;
- permissible levels of radiation and methods of their control;
- allowable temperatures of controls and external surfaces of production equipment;
- allowable effort on the controls;
- the presence of protective interlocks, braking devices and other means of protection.

Requirements for the means of protection included in the design, due to the features of the design, placement, control of work and the use of the means in question.

Including:

To protective barriers, screens and means of protection against ultrasound, ionizing and other radiation;
- to the means of removal from the working area of ​​substances with dangerous and harmful properties;
- to protective interlocks;
- means of signaling;
- signal painting of production equipment and its components;
- to warning labels.

Protective fences included in the design of the equipment must comply with GOST 12.2.062. Easily removable guards must be interlocked with the starting devices of electric motors to turn them off and prevent starting when they are opened or the guards are removed.

Process control

In connection with the introduction of an integrated quality management system at many plants, the control functions performed by the work operators have been expanded.

However, this progressive business may turn out to be ineffective if it is not provided with appropriate organizational and technical training (systematic maintenance of equipment and tooling in good condition, training workers in control methods and providing them with the necessary measuring instruments, compliance with the rules of GOT in the workplace, etc.) .

If for some reason the worker-operator is unable to provide a reliable check of the quality of his work (for example, due to the lack or insufficient accuracy of measuring instruments, the unsuitability of the workplace for quality control, etc.), he is obliged to involve for this OTC workers.

At the same time, it should be noted that the introduction of self-control in the workplace and a system of personal brands does not at all relieve inspectors and other specialists from checking the quality of technological operations.

But at the same time, their importance in the prevention of production defects and the timely transmission of information to workers about the appearance of any errors (symptoms of marriage) and the need to take appropriate measures to prevent them in further work becomes more significant.

This is achieved by the so-called "flying" control, in which QCD employees must systematically perform random checks of product quality during its manufacture. Thus, the main task of technical control is the prevention of defects, and not their passive accounting.

Process map

It also defines the place of work, the type and size of the material, the main surfaces of the workpiece and its installation, working tools and fixtures, as well as the duration of each operation.

The technological process is developed on the basis of a drawing, which for mass and large-scale production must be made in great detail. With make-to-order production, often only a route workflow is given, listing the operations required for processing or assembly.

ball bearing

The time required for the manufacture of a product in a single and small-scale production is set approximately on the basis of timing or accepted standards, and in large-scale and mass production - on the basis of design and technical standards.

Basing is called giving the workpiece or product the required position relative to the selected coordinate system.

A base is a surface, a combination of surfaces, an axis or a point that belongs to a workpiece or product and is used for basing.

By purpose, the bases are divided into design, main, auxiliary, technological and measuring.

The design base is used to determine the position of a part or assembly unit in a product.

The main base is a design base that belongs to a given part or assembly unit and is used to determine its position in the product. For example, the main bases of a shaft assembled with bearings are its bearing journals and a thrust collar or flange.

knee shaft

An auxiliary base is a design base that belongs to a given part or assembly unit and is used to determine the position of the product attached to them. For example, when connecting a shaft to a flanged bushing, the auxiliary base can be the shaft bore diameter, its collar and key.

The technological base is a surface, a combination of surfaces or an axis used to determine the position of a workpiece or product in the manufacturing or repair process. For example, a part base plane and two base holes.

The measuring base is used to determine the relative position of the workpiece or product and measuring instruments.

Types of technological processes

A single technological process is applicable only for the manufacture of one specific product, and a standard technological process is applicable for the manufacture of a group of similar products.

A single technological process is a process of manufacturing or repairing a product of the same name, size and design, regardless of the type of production. The advantages of a single technological process include, on the one hand, the ability to take into account all the features of a given product, and on the other hand, the most efficient manufacture of a product by taking into account specific production conditions (available technological equipment, fixtures, tooling, workers' qualifications, etc.). ).

Along with the advantages of a single technological process, there are also disadvantages. It takes a lot of time and effort to develop it.

The time spent on the development of a technological process can be many times greater than the time spent on its implementation. If a large number of products are manufactured, then the share of time spent on the development of the technological process per product will be insignificant, but with a small output of products, this share will increase sharply. In this case, an enlarged technological process is developed, for example, only a route description of the technological process is created, which includes a sequence of operations and equipment, but without indications of transitions and process modes. Everything else is left to be decided directly by the worker, who must have the appropriate qualifications. As the volume of manufactured products grows, the development of the technological process is carried out in more detail.

In a single production, the high duration of the development of the technological process often conflicts with the duration of the process itself. The more thoroughly and in detail a single technological process is developed, the more time is required for its development and the higher the qualification of the technologist should be. However, under certain conditions, the time spent on the development of the process becomes much greater than the time spent on its implementation. An illustration of this situation can be the technological process of manufacturing parts on a CNC machine, where its development is distinguished by great care and detail. So, for example, the documentation of the technological process of manufacturing a part on a CNC machine contains a set-up chart, an operational-technical chart, a tool movement scheme, an operational settlement-technical chart, a programming chart, drawings special tool and rigging. All this leads to an increase in the complexity of the development of the operation; for example, only the development of a control program and its debugging for highly complex parts requires several working days for a programmer, while processing a small batch of such parts can fit into one work shift.

The design of a single technological process is characterized by a large number of possible solutions for each product to be manufactured. Therefore, in the conditions of a single production with a relatively short time allotted for the development of the process, the possibility of reinforcing the decisions made with objective technical and economic calculations is very limited.

In mass production, the high labor intensity of a thorough development of a single technological process turns out to be justified, since its value is incomparably small compared to the labor intensity of manufacturing the entire volume of products of a given name. Justifies itself in mass production and the use of special equipment, tooling, characterized by high-performance workflows.

Disadvantages of single technology. In mass production, they are manifested in the long duration of the technological preparation of production, due to the need to create special technological means.

The widespread use of a single technology on the scale of the entire machine-building production of the country leads to large losses. The fact is that, on average, manufactured products consist of approximately 70% of general machine-building units and parts that are close in their structural structure. But at thousands of machine-building enterprises they are manufactured according to single technological processes, which differ little in efficiency from each other, but often use original equipment, and in large-scale and mass production - original technological equipment. At the same time, progressive highly efficient solutions developed at any one enterprise and requiring large labor costs are lost in a huge variety of developments and practically do not find application in other enterprises.

All the listed negative aspects of a single technology were the reason for the search for a new type of technology free from these shortcomings. The first step in this direction was the development of a standard technology, when in the 30s of the XX century prof. A. P. Sokolovsky expressed the idea of ​​typification of technological processes.

A typical technological process is characterized by the unity of the content and sequence of most technological operations for a group of products with common design features.

The standard technology is based on the classification of products into classes - subclasses - groups - subgroups - types. A type is a group of similar products, among which a typical representative is selected that has the largest set of properties of products included in this group. A technological process is developed for a typical representative, according to which all products of this type are manufactured. If a particular product lacks a particular characteristic (for example, some kind of surface), when developing a workflow, the corresponding operation is excluded from the standard process.

Thus, the standard process to a certain extent resolves the contradiction between the large time spent on the development of the process and the short time for manufacturing the product, since the time spent on developing the working process for the manufacture of a particular product is sharply reduced. By developing one standard process for a group of parts that are similar in their design, it is possible to develop a more perfect process, since more time and money can be spent on its design. Using a standard process, a working technological process for a part from a group will be developed quickly and efficiently.

Typical processes make it possible to avoid repeated and new developments in the design of working technological processes, as a result of which the work of the technologist is facilitated and the time spent on development is reduced.

An important circumstance: a typical technological process, acquiring universality, at the same time loses its individual features. Indeed, a typical technological process for manufacturing parts is developed for a group of structurally similar parts included in one type. According to this standard process, all the parts of the group are made, despite the fact that they differ from each other in some way. This is the universality of a typical technological process.

The loss of individuality of the standard process lies in the fact that it does not take into account the differences noted above, the specifics of products included in one type. As you know, in each type, a typical part is selected from a group of parts, which differs in the most common structural forms, dimensions, accuracy requirements, and other quality indicators. A standard part is usually the most complex of all the parts included in this type. Therefore, if a single technological process were developed for each part from this group, then it would be more efficient than a standard process, since it takes into account all the features of the part (in other words, the loss of individuality does not allow the standard process to become optimal for each part of this group) .

The more products in the group differ in their design and quality requirements, the more the typical process differs from the optimal one. This is one of the limitations of expanding a group of products for one standard technological process. As a result, manufactured products have to be divided into more types, which leads to an increase in the number of standard processes and reduces the efficiency of typing.

Generally standard technology promotes:

1) reducing the diversity of technological processes and introducing uniformity in the manufacture of similar products;
2) introduction and dissemination of best practices and achievements of science and technology;
3) simplifying the development of work processes and reducing the time spent on their development;
4) reducing the variety of technological equipment of technological processes;
5) development of new highly efficient technological processes.

The effectiveness of single and standard technologies will be different depending on the type of production. In mass production, it is more efficient to use a single technological process, as it allows you to create an optimal technological process, resulting in a high total economic effect.

With the growth of the variety of manufactured products, the decrease in their serial production, the size of the batches, the loss of time associated with frequent readjustments of technological equipment and tooling increases. As a result, the efficiency of production decreases, the cost of manufacturing products increases. And the wider the range of products produced and the smaller their serial production, the lower the production efficiency.

Under these conditions, the problem arose of grouping products that are distinguished by the homogeneity of manufacturing technology, which makes it possible to reduce the number of equipment changeovers and increase the size of batches arriving for processing.

As a result of solving this problem, a new type of technology appeared - group technology, the founder of which is prof. S. P. Mitrofanov.

If standard technology is aimed at reducing the labor intensity of technological preparation of production, increasing the efficiency of technological processes and disseminating progressive solutions, group technology is designed to increase the efficiency of the production process.

Group technological process is the process of manufacturing a group of products with different design, but common technological features.

The batch process has found application in small-scale and serial production. The fundamental essence of group technology lies, first of all, in grouping products into technology groups technologically similar. A group technological process is developed for a complex product. Unlike a typical product, a complex product is a "collective" one, often not existing in reality, combining the features of most products included in the group. For a complex product, a technological process is developed and all products of this group, being, as a rule, simpler than a complex product, are manufactured according to this technological process, skipping individual technological transitions. All products assigned to this technological process are manufactured in batches.

As a complex product of a technological group, some product from the group or an artificially created product is used. For example, a complex part is formed as follows: the most complex part is taken, which includes all the surfaces of other parts, and if it does not contain all the surfaces contained in other parts of the group, then the missing surfaces are artificially added to it.

Distinguish group operation and group technological process. A group technological operation is developed to perform technologically homogeneous work in the manufacture of a group of products at a specialized workplace, subject to the possibility of partial adjustment of the technological system. A group technological process is a complex of group technological operations performed at specialized workplaces in the sequence of a technological route for a group of products, elements.

The use of group technology is especially effective when, on its basis, in serial and small-scale production, it is possible to create group in-line or even automatic lines for the manufacture of products or parts of individual groups. The creation of such lines is usually based on a combination of the principles of typification of technological processes and group processing, i.e. when a typical route is used (for example, when processing workpieces for individual group operations performed on machines with group settings, and with the widespread use of group changeover devices).

The use of group technology is more effective, the larger the technology group.

When introducing group technology, difficulties arise associated with the organization of large technological groups, not only due to the complexity in building group adjustments and fixtures, but also because of the need to take into account scheduling for the release of products.

Products manufactured according to group technology, although similar, have differences, therefore, with rare exceptions, it is not possible to completely get rid of the readjustment of equipment.

As the range of parts in a group expands, when developing a group setup, its complexity, the number of positions, and the downtime of tool positions increase. This limits the range of parts in the group leads to an increase in the number of groups and, consequently, an increase in the number of group technological processes (operations). Group technology justifies itself under the condition of repeated repetition of the production of this technological group of products. If repeatability is absent or insignificant, then the additional costs for technological preparation, which are much higher compared to a single technology, do not pay off (an example of the effective use of group technology can be the aviation industry, where there is a high repeatability of groups).

The practice of introducing standard and group technological processes shows that, despite the obvious advantages, the share of their implementation is low and a single technology still dominates. One of the main reasons for this is the lack of classification of products into types, groups, which are used in the development of standard and group processes. An analysis of these classifications shows that in both cases, in an explicit or implicit form, not constructive, but technological characteristics. This leads to the fact that at enterprises that differ in the composition of technological means and the qualifications of workers, the same product range will be divided into different groups. On the other hand, it is worth changing the technology and equipment used at the enterprise, as types and groups will have to be changed. To minimize these shortcomings, it is necessary to classify products into groups not by technological, but by design features, which will reduce the variety of standard and group processes and expand the scope of their application.

Summing up the analysis of various types of technological process, the following can be noted:

The use of a single process allows you to develop optimal processes, but this leads to a large investment of time for their development;
- the use of a standard technological process reduces the volume and terms of technological preparation of production, but does not provide optimal process for each part of the same type;
- the use of a group technological process, although it increases the size of the batch, but requires the repeatability of the production of products, which significantly reduces the area of ​​its effective application.

All three types of technology are not flexible, as they do not allow you to change the route if necessary.

One of the main reasons for the shortcomings of all types of technological processes is the description of the product at the geometric level, when the part is represented by a set of elementary geometric surfaces, and the assembly unit is a set of parts as geometric bodies.

This leads to the fact that the technologist, developing the technological process, strives to produce such combinations of surfaces at operations that allow achieving the highest productivity. However, in this case, the connections between the surfaces are often violated, due to the joint performance of the functions of the part. As a result, firstly, there is a multivariance of the technological process due to the large number of combinations of surfaces manufactured at operations, and secondly, due to the manufacture of functionally related surfaces at different operations, complex technological dimensional relationships arise, leading to the need to introduce additional operations. .

All this leads to an unreasonable variety of technological processes, an increase in the complexity of their development, causes difficulties in the typification of technological processes and in grouping parts in the development of group processes.

If the part is described by functional blocks in the form of surface modules united by the joint performance of service functions, then the geometric feature becomes secondary, and elementary surfaces are part of the surface modules and are not independent objects in the development of technological processes.

Given the limited range of MPs and their high repeatability, it is possible to significantly reduce the variety of technological operations in terms of the composition of manufactured MPs. As a result, the development of technological processes, their typification and grouping of parts when using group processes will be simplified. All of the above is also true for assembly technological processes, if the assembly unit is considered as a set of connection modules.

In order to realize the above advantages of describing the product as a combination of MP and MS, the construction of a technological process should be considered as a layout of modules for manufacturing MP (MS) that are part of the part (assembly unit).

In this regard, the process was called a modular technological process, respectively, it can be a single, typical, group process, and is the result of further improvement in the methodology for developing technological processes, starting with the description of the product.

A modular technological process is a technological process built from the modules of the MP or MS manufacturing processes that are part of the manufactured product. The modular technological process is based on the objective existence of MP and MS, which are structural elements of products. A narrow nomenclature and a limited number of characteristics describing them opens the way to the utilization of design solutions for MP, MS, unification of their characteristics and, on this basis, the development of modules for technological support for manufacturing MP and obtaining MS.

The technological support modules include modules of the technological process (MTI) for the manufacture of MPs and the assembly process (MTS) for obtaining MS, modules for technological equipment (MO), tool adjustment (MI), technological bases (MTB), fixtures (MPr) and control and measuring devices (MKI).

Since modular technological support is being developed for standard MP and MS with unified characteristics, it has a high level of generalization, therefore, a wide scope. Having technological support at the modular level, a modular manufacturing process, for example, parts, is built as follows. First, the sequence of formation of all MP parts from the workpiece is determined, then i > 1 MTI, MTB, MO, MI, MPR, MKI, necessary for the manufacture of each MP, are called from the data bank, then MTI are combined into operations.

Modular technological process combines the advantages of single, standard and group technological processes. Indeed, a modular technological process is developed in the same way as a single technological process, taking into account all the features of the product. However, in contrast to a single process, the complexity of its development is low, since it is built by the assembly method from the available modules of technological support.

The idea of ​​typing in a modular technological process is implemented at the level of technological support modules, while typing is carried out more efficiently, since MP and MS modules, unlike products, are described by a small number of characteristics.

For example, even a relatively simple part contains a dozen or two surfaces and has a wide variety of design options. At the same time, the requirements for the accuracy and quality of the surface layer of the surfaces of such a part may be different, which further increases its diversity. As a result, for the manufacture of such a multitude of parts, a large number of typical technological processes will be required.

In contrast to a part, MP of the same name has a smaller number of design options, contains, with rare exceptions, no more than three surfaces, which significantly reduces the diversity of MG1 and reduces the number of typical modules of the technological process.

The idea of ​​group technology, which consists in the organization of technological groups from different products, in the conditions of modular technology is solved the best way. The fact is that, due to the limited range of MP and MS, it is relatively easy to form technological groups even in the conditions of a single production, i.e., the repeatability of manufactured products is not required.

In conclusion, we note that the modular technological process acquires some flexibility, allowing, within limited limits, to change the sequence of operations. This is explained by the fact that in traditional technological processes, the functionally connected surfaces of the part can be manufactured in different operations. For example, such surfaces of a part as an end face, a hole and a keyway, forming a set of bases (MPB311), can be made in different operations. As a result, complex dimensional relationships arise between operations, which are violated when the sequence of the operation is changed, which can lead to marriage. Therefore, changing the developed route process is unacceptable. In a modular technological process, the functionally connected surfaces of a part are always combined by the corresponding module and are manufactured in one operation. This greatly simplifies the dimensional relationships of the technological process, makes them transparent, which makes it relatively easy to determine the possibility of changing the processing route.

The principles of building modular technological processes allow building machine-building production in a new way, which is based on the end-to-end application of the modular principle throughout the entire production chain: product - technological processes - technological systems - organization of the production process.

Design of technological processes

In accordance with the third principle, the technological process must comply with the requirements of safety and industrial sanitation according to the system of labor safety standards (SSBT). Environmental factors must be taken into account. The design of technological processes aims to give a detailed description of the manufacturing processes of products with the necessary technical and economic calculations and justification of the chosen option, since technological processes are characterized by their multivariance.

For example, the surfaces of the same part can be processed in different sequences by different methods; the same assembly unit, as a rule, can be assembled using different methods to achieve accuracy. Of several possible options for the technological process of manufacturing the same product, equivalent in terms of technical principle design, choose the most efficient and cost-effective option.

With equal productivity of the compared options, the most cost-effective one is chosen, and with equal profitability, the most productive one. The efficiency and profitability of the designed process is determined by all the elements of which they are composed. tasks process design are the determination of the conditions for the manufacture of products, the determination of the type of production, the types of initial blanks, the design of a technological processing route, the identification of the necessary means of production and the procedure for their use, the determination of the cost and labor intensity of manufacturing products, the determination of the initial data for scheduling, for the organization of technical control , determination of composition work force.

The solution of design problems depends on a large number of factors related to the official purpose of the product, its design and technological parameters and the state of production. When solving these problems, optimization of technological processes should be carried out, which consists in ensuring the release of the required number of products of a given quality at the lowest possible cost of production with the best performance of all elements of the processes and lowest cost time. Optimization is a time-consuming process and is most effectively solved using computer science.

Technological processes are developed in the design of new, reconstruction of existing enterprises, as well as in the organization of the production of new products at existing enterprises. At the same time, the accepted options are the basis for all technical and economic calculations and design decisions. The level of development of technological processes determines the level of work of the enterprise. In addition, technological processes are developed and adjusted in the conditions of existing enterprises in the production of mastered products. This is caused by continuous constructive improvements in products, the need for the systematic use and implementation of the achievements of science and technology in the existing production through the development and implementation of organizational and technical measures, the need to eliminate bottlenecks in production.

Execution of a workflow

It uses two principles:

1. Differentiation, when the number of surfaces to be machined in one operation decreases, while the number of operations increases. The limit of differentiation is when one simplest surface is processed in one operation.

The advantages of the differentiation principle are the possibility of using methods of various physical nature for processing (for example, electric spark piercing of shaped holes), special high-performance equipment (for example, plunge grinding machines), optimal processing modes for each surface, etc. Differentiation of technological processes is used both in the mass production of parts of a simple configuration (for example, piston pins of an internal combustion engine) and in the single-piece production of parts with complex profiles (for example, turbine blades of gas turbine engines).

2. Concentration, when as many surfaces as possible are processed in one operation, while the number of operations in the technological process decreases. The concentration limit is when the entire technological process degenerates into one operation.

The advantages of the principle of concentration are: increasing the accuracy of the relative position of the treated surfaces; processing productivity increases many times due to the use of multi-spindle, multi-support, multi-place machines; simplification of the organization of production, since planning and accounting are carried out according to operations, and their number is reduced; reduction in the number of workpiece installations, which especially reduces the time spent on transportation in the manufacture of heavy and large-sized parts; time and costs for production preparation are reduced due to a decrease in the range of devices for installing and fixing workpieces.

Technological equipment is called production tools necessary to perform a certain part of the technological process, in which materials, semi-finished products and blanks are placed and fixed, means of influencing them and, if necessary, energy sources (metal-cutting machines of universal and special purpose, presses, hammers, casting machines, furnaces, test benches, etc.).

Technological equipment is called production tools added to technological equipment and necessary to perform a certain part of the technological process (tools, fixtures, means of mechanization and automation of production processes). Tools can be working and control (measuring). The working tool is used for direct impact on the material being processed in order to convert it into finished parts or assembly units (the categories of workers include cutting tools used in processing on machine tools(cutters, drills, cutters, broaches, etc.), dies for cold sheet and volumetric hot stamping, casting molds, riveting, welding tools, etc.). The measuring tool is used to measure the geometric parameters of manufactured products (universal tools for measuring linear and angular dimensions (rulers, calipers, micrometers, goniometers) and special ones (gauges, templates, etc.)). Devices are used to install and fix workpieces in a given position in technological equipment in the manufacture of parts or to install and fix parts in an assembly position in the manufacture of assembly units. Means of mechanization and automation are used to mechanize and automate production processes in order to facilitate and increase the productivity of performers.

Technological equipment, technological equipment and means of mechanization and automation of production processes are collectively called technological equipment. The type and quantity of technological equipment used is determined by the technological process for the manufacture of one or another structural element of the aircraft.

Technological equipment and tooling for the purpose of practical use are adjusted. Adjustment is the preparation of technological equipment and technological equipment for a specific technological operation (installation of a fixture on the machine, switching the speed and feed of the machine, installing a stamp and setting up the press, regulating and setting the set temperature in the furnace during heat treatment, etc.). The term “adjustment” is also used, which refers to additional adjustment of technological equipment and (or) tooling in the process of operation to restore the values ​​of parameters achieved during adjustment.

Process characteristic

1) production of products from the processing of raw materials to cooking and its sale;
2) preparation of products from semi-finished products and their sale;
3) organization of food consumption with little preparation for sale. In other words, according to the nature of the organization of production, there are enterprises with a complete and incomplete technological cycle.

Raw materials are products from which culinary products are produced according to the scheme: processing of raw materials - cooking - sale. Semi-finished products are products that have undergone primary processing at procurement enterprises and have varying degrees of readiness. Finished products - dishes and culinary products ready for sale.

The products produced by public catering enterprises are perishable and require quick sale. Various products and raw materials used for cooking and culinary products also do not withstand long periods of storage. In this regard, public catering enterprises should ensure the maximum reduction in the periods of storage, processing of raw materials and the sale of finished culinary products. Therefore, the commercial success of an enterprise and the sanitary safety of its products directly depend on how correctly and accurately the order is drawn up and the work of suppliers of semi-finished products and raw materials is coordinated. In order to correctly determine the volume production program and range of products, it is necessary to take into account the demand of consumers for different kinds dishes and culinary products.

Of great importance for the proper organization of the technological process at catering establishments are the observance by cooks of the norms for investing raw materials in accordance with approved recipes, the organoleptic evaluation and rejection of ready-made dishes and culinary products.

One of the main factors that determine the characteristics of the production process of public catering enterprises is their transfer to work with semi-finished products. Centralized and integrated supply of enterprises with semi-finished products creates an opportunity for the most rational use technological equipment, increasing labor productivity, narrower specialization of workers, can reduce the cooking process, reduce production costs.

A shopless structure of production is being established at enterprises with a small volume of production or working on semi-finished products. Here, all production processes are carried out by one or more teams, which are subordinate to the production manager. Such an organization of labor makes it possible to use chefs more effectively, to practice combining professions, etc.

All production facilities of public catering enterprises are usually divided into procurement, pre-cooking, auxiliary and auxiliary. Procurement - these are vegetable, meat, fish and poultry shops at large enterprises, at enterprises of small capacity - vegetable and meat and fish shops. Pre-cooking includes hot and cold shops, to the ancillary - a shop for the production of soft drinks (at large enterprises), to the auxiliary - distributing, bread slicers, pan-washers.

The main conditions for the proper organization of the technological process of cooking: the optimal area of ​​​​production premises, their rational placement and provision of production workshops necessary equipment.

As the practice of work of domestic and foreign enterprises has shown, the linear principle of equipment placement is most appropriate for modern public catering enterprises. The lines are completed from separate sections, specialized in the performance of certain technological operations. All sections must be the same in height and width (depth), and their length must be a multiple of a certain value (modulus) established for all sections. Equipment designed for completing such lines is called sectional modulated equipment.

Sanitary standards for premises, as well as the existence of conditions that ensure compliance with labor protection laws for workers, are something that must be observed both in large state or joint-stock companies and in private enterprises.

In industrial premises of catering establishments, the ceilings should have a height of at least 3–3.3 m. For walls, adhesive paint of light shades is used, and wall panels to a height of 1.7 m are lined with light ceramic tiles, which are easy to sanitize.

Floors are covered with tiles and other waterproof materials that are easy to clean.

While creating necessary conditions for the work of workers is of great importance temperature regime in industrial premises. Thus, in the blank shops the air temperature should not exceed 16–18°С, in the hot shop – 22–25°С. Special ventilation systems must ensure the removal of superheated air, vapors and exhaust gases. To do this, install mechanical exhaust and supply and exhaust ventilation. During exhaust ventilation, stale air is removed from the premises by a fan, and fresh air enters through the pores of the walls or specially left channels and openings in the walls and coatings, as well as through the ventilation grills. In case of supply and exhaust ventilation, separate fans are installed in the premises, causing the movement and exchange of air, or ventilation supply and exhaust installation when air enters and is removed through channels made of tin, brick or plastic, and the regulation of the air flow occurs with the help of gratings.

To create and maintain an artificial microclimate and the specified temperature, humidity, air mobility and purity in industrial premises, automatic air conditioning units are used.

Production facilities must be equipped with cold, hot water and sewerage. In the event of a lack of hot water, backup water heaters should be installed. Water is supplied to bathtubs, sinks, as well as stoves, boilers and other equipment. The sewerage system provides for the rapid removal of wastewater. Baths, sinks, washbasins are equipped with hydraulic seals that prevent the penetration of sewer odors.

Use of technological processes

Schumpeter identified 5 new combinations of factors:

1. use new technology, new technological processes;
2. introduction of products with new properties;
3. use of new raw materials;
4. changes in the organization of production and its logistics;
5. the emergence of new markets.

New combinations of factors of production are called innovations (innovations).

Schumpeter expressed an idea that still influences economic thought: capitalism is by nature a form of economic change and can never be stationary. The main impetus that starts the engine of capitalism comes from new consumer goods, new modes of production and distribution, new markets, new ways of organizing production, which the capitalist enterprise creates. This process of creative destruction is a factor that touches the essence of capitalism.

In the fundamental work "Business Cycles" (1939), Schumpeter proposed three types of cycles. Each large cycle of the conjuncture includes several medium cycles, and each medium cycle includes several short ones.

Long waves are cycles with a period of 55 years, first discovered by N.D. Kondratiev. Medium cycles - 10 years - are associated with the replacement of the active part of capital in the form of machine tools, Vehicle. Short cycles (about 2 years) are extended by Schumpeter to market changes in relation to certain types of products (modifications).

Economists are now convinced that over the past 250 years, waves of major innovations have occurred more or less regularly, with a cycle of approximately fifty years. In the first few years of the cycle, new technological potential is accumulated. Then the wave of innovations is gaining the greatest strength. Then, during commercial exploitation, the pace of events gradually slows down.

Thus, since the Industrial Revolution, historical waves of intense technological change characterized by opportunities for rapid economic growth and radical social transformation.

The cause of dynamic change, according to Schumpeter, is the intrusion of the innovator-entrepreneur who needs financial resources for innovation. Therefore, investment is an integral part of innovation activities.

The first wave, which was based on new technologies in the textile industry, using the possibilities of coal and steam, covers the period from 1790 to 1840.

The second wave (1840-1890) is directly related to the development railway transport and mechanization of production.

The third wave (1890-1940) was based on the power industry and advances in chemistry.

The fourth wave (since 1940) is associated with the rapid development of electronics, computer technology, and the dominance of mass production.

According to this theory, the world is currently experiencing the fifth wave of technological changes associated with the rapid development of information and telecommunications technologies. Researchers believe that biotechnology will become an important component of the fifth wave.

In accordance with the concept of wave economic activity, periods of economic growth are replaced by recessions and depressions. The first wave of the late 18th century was followed by a period of recession, the second wave (Victorian era) was followed by a deep recession, the third wave at the end of the 19th century ended with the Great Depression, the fourth wave of economic growth after World War II was followed by a crisis accompanied by high unemployment .

Economists have differing views on the length of the waves, the contraction of cycles, whether the fifth and subsequent waves will alternate with the same severe drops as in the past. Yet most of the leading economists of the century, from Keynes to Samuelson, believe in waves of economic activity generated by changes in investment behavior in conjunction with technological change.

Complex technological process

A simple process is a process consisting of sequentially performed operations (manufacturing of one part, a batch of identical parts, a group of different parts that have technological similarities and are processed at the same workplace, section, line). The order of operations in this case is determined by the manufacturing technology of the part.

A complex process is a process consisting of sequential and parallel operations. For example, the manufacture of an assembly unit consisting of several parts, the manufacture of a product that includes a certain number of parts and assembly units. The structure of a complex process depends not only on the composition of the manufacturing and assembly processes, but also on the order in which they are performed, which depends on the design of the assembly unit or product.

The concept of a complex technological process can be found in R 50-601-20-91 "RECOMMENDATIONS for assessing the accuracy and stability of technological processes (equipment)".

Complex technological processes have such a property as emergence (the properties of a complex process are not a simple sum of the properties of its constituent elements).