Technological operation- completed part of the technological

process performed at one workplace. For surgery

the norm of time is determined and the operation is thus

unit for planning the scope of work and jobs in the shop

Technological operation is the main structural unit of TP. This part of the process associated with the processing of one or more simultaneously processed workpieces, one or more simultaneously working workers, at one workplace and continuously.

Continuity condition operations means the performance of the work envisaged by it without switching to the processing of another product or the same product, but at a different workplace. For example, processing a stepped roller in the centers on a lathe is one technological operation if it is performed in the following sequence: the workpiece is installed in the centers, the roller is turned from one end, the workpiece is removed, the clamp is reinstalled and the workpiece is reinstalled in the centers, the roller is turned from the other end.

Work similar in content to the roller can be performed in two operations:

Fasten the clamp, set the workpiece in the center, grind from one end and remove the clamp

Fasten the clamp on the other end of the workpiece, install it in the centers and grind from the other end.

However, these actions will be included in different operations if the secondary installation and processing of the second end of the roller does not follow immediately after processing the first end, but with a break to process other workpieces of the batch (i.e., first all workpieces are processed from one end, and then everything - from the other). The above example shows that the composition of the operation is set not only on the basis of purely technological considerations, but also taking into account organizational expediency.

The technological operation is the main unit of production planning and accounting. On the basis of operations, the complexity of manufacturing products is determined and time standards and prices are established.

Technological transition

operations performed by the same means

technological equipment at constant technological

modes and settings.

Auxiliary transition - completed part of the technological

operation, consisting of the actions of a person and / or / equipment,

which are not accompanied by a change in the properties of the objects of labor, but

necessary to perform a technological transition /example -

workpiece setting, tool change, etc./. Auxiliary

transitions are not recorded in the workflow. At

simultaneous processing by several tools of several

transition surfaces is called combined. Often found

operations consisting of only one technological transition.

working stroke - the completed part of the technological transition,

consisting of a single movement of the tool relative to

workpiece and is accompanied by a change in shape, size, quality

surface and workpiece properties.

Technological operation- this is a complete part of the technological process, performed at one workplace.

A technological operation is the basic unit of production planning and accounting. On the basis of operations, the complexity of manufacturing products is determined and norms of time and prices are established, the required number of workers, technological equipment is determined.

setup- part of the technological operation, performed with the unchanged fixing of blanks or assembled assembly units. Designation of the installation A, B, C, D, etc.

Position- a fixed position of the device with the workpiece permanently fixed in it relative to the working bodies of the equipment for performing part of the technological operation.

Technological transition- the finished part of the technological operation, characterized by the constancy of the tool used and the surfaces formed during processing or connected during assembly. Accompanied by a change in the state of the production object.

working stroke- the completed part of the technological transition, consisting of a single movement of the tool relative to the production object, accompanied by a change in the state of the object.

Auxiliary transition- a completed part of a technological operation, consisting of the actions of a worker and equipment. It is not accompanied by a change in the state of the production object, but is necessary to perform a technological transition.

Auxiliary move- the completed part of the technological transition, consisting of a single movement of the tool relative to the production object, and not accompanied by a change in its state.

Algorithm for designing TP for the manufacture of machine parts

1) analysis of initial data; 2) search for analogues of the technical process; 3) selection of the initial workpiece; 4) selection of technological bases; 5) drawing up a technological processing route; 6) development of technological operations; 7) regulation of the technological process; 8) determination of safety requirements; 9) choice of the optimal variant; 10) design of the technical process.

Determination of cutting conditions during machining (single and multi-tool)

Single tool processing .

1 ) Determine cutting depth t according to the results of the calculation of operating allowances. In single-pass machining, we take the average value of the allowance. If there are two passes, then 70% of the allowance is removed for the first pass, and 30% for the second.

2 ) Assign filing s. For turning, drilling, grinding, the feed per revolution of the workpiece is determined. S o or tool, for milling - feed per tool tooth S z .S z =S o /z, where z is the number of cutter teeth. When roughing, the maximum allowable feed is selected; when finishing - depending on the required accuracy and roughness of processing, taking into account the geometric parameters of the cutting part of the tool. The amount of feed determined according to the standards or using other methods (linear programming, simplex method, etc.) must be coordinated with the passport data of the machine.

3 ) Determine cutting speed value v:

where the values ​​of the coefficients are determined from reference books.

4 ) We expect frequencyn workpiece or tool rotation:

where v - cutting speed, m/min; D is the diameter of the workpiece (tool) in mm.

5 ) We calculate the coordinate components of the cutting force using formulas of the form:

values ​​other than t and S are selected from reference tables.

6) We check the cutting mode according to the power and power characteristics of the machine. To do this, we compare the obtained value of the coordinate component P x of the cutting force acting in the feed direction with the allowable force of influence on the feed mechanism R x add.

Cutting power:

N e \u003d, kW or other dependencies with verification

N e ? N dvz,

where N dv is the power of the drive motor of the main movement of the machine, s is the efficiency of the drive.

If the given ratios are not maintained, it is necessary to correct the selected values ​​of feed and cutting speed or replace the process equipment.

Multi-tool processing.

In the case of parallel processing, the depth of cut and feed for each of the tools are selected from the condition of their independent operation, i.e. according to the method of single-tool processing. Then the feed of the tool block is determined - the smallest technologically admissible feed from the selected values. The cutting speed is determined by the presumably limiting tool. They can be tools that process areas of the largest diameter and greatest length. For several supposedly limiting tools, the cutting time coefficients are found:

where Lp is the cutting length of an individual tool, Lpx is the length of the working stroke of the entire tool block.

where Tm is the normalized tool life.

Based on the found values ​​of resistance T, cutting speeds are found for each of the supposedly limiting tools. In fact, the limiting tool will be the one with the lowest defined cutting speed. This value is adopted for the operation of the entire tool block. Next, the rotational speed is determined n and its adjustment is carried out according to the passport of the machine. Next, we calculate total cutting force and power.

The product is the result of a manufacturing process.

Manufacturing process it is a set of all actions of people and tools of production necessary at a given enterprise for the manufacture or repair of manufactured products.

The production process includes not only the main processes directly related to the manufacture of parts and assembly units, but also all the necessary processes, for example: production preparation; receipt, transportation, control and storage of materials (semi-finished products); equipment repair, etc.

Technological process(TP) is a part of the production process that contains actions to change and then determine the state of the subject of production.

Technological method- a set of rules that determine the sequence and content of actions when performing shaping, processing or assembly, movement, including technical control, testing in the technological process of manufacturing or repair, established regardless of the name, size or design of the product.

According to the execution method, there are three main parts of the technological process: shaping, processing and assembly.

When changing the position of the workpiece being processed, the operation may consist of several setups and positions.

Installation- this is part of the technological operation, performed with the unchanged fixing of the workpieces being processed or the assembled assembly unit.

Position- this is a fixed position occupied by an invariably fixed workpiece or an assembled assembly unit, together with a fixture relative to a tool or a fixed piece of equipment to perform a part of an operation.

Reception- a complete set of human actions used in the implementation of the transition or part of it and united by one purpose. For example, the auxiliary transition "installing the workpiece in the fixture" includes the following steps: take the workpiece, install it in the fixture and fix it.

General allowance a layer of material is called for processing, which is the difference between the dimensions of the workpiece and the dimensions of the finished part.

Base surface The surface of the workpiece being machined is called the surface on which the workpiece is installed in the fixture and oriented during processing on the machine relative to the cutting tool.

The technological process is usually divided into parts called operations.

Technological operation call the finished part of the technological process, performed at one workplace. An operation encompasses all the activities of equipment and workers on one or more jointly processed or assembled objects of production. So, when processing on machine tools, the operation includes all the actions of the worker to control the machine, as well as automatic movements of the machine associated with the process of processing the workpiece until the moment it is removed from the machine and the transition to the processing of another workpiece.

The operation is characterized by the invariance of the workplace, technological equipment, the object of labor and the performer. When one of these conditions changes, a new operation takes place.

The content of the operation is determined by many factors and, above all, organizational and economic factors. The scope of work included in the operation can be quite wide. The operation can be the processing of only one surface on a separate machine. For example, milling a keyway on a vertical milling machine. The manufacture of a complex body part on an automatic line, consisting of several dozen machines and having a single control system, will also be an operation.

The technological operation is the main element of production planning and accounting. According to the operations, the labor intensity of the process, the necessary equipment, tools, fixtures, and the qualifications of workers are determined. All planning, accounting and technological documentation is compiled for each operation.

The operations that are part of the technological process are performed in a certain sequence. The content, composition and sequence of operations are determined process structure .

The sequence of passage of the workpiece of a part or assembly unit through the shops and production sites of the enterprise when performing the technological process of manufacturing or repair is called technological route .

Distinguish intershop and intrashop technological routes.

The structure of the operation involves dividing it into its constituent elements - setups, positions and transitions.

To process a workpiece, it must be installed and fixed in a fixture, on a machine table or other type of equipment. When assembling, the same should be done with the part to which other parts are to be attached.

setup- part of the technological operation, performed with the unchanged fixing of the workpieces being processed or the assembled assembly unit.

Each time the workpiece is removed again and then fixed on the machine, or when the workpiece is rotated through any angle to machine a new surface, a new setting takes place.

Depending on the design features of the product and the content of the operation, it can be performed either from one or from several installations. In the technological documentation, the installations are indicated by the letters BUT, B, AT etc. For example, when processing a shaft on a milling and centering machine, the milling of the ends of the shaft on both sides and their centering are performed sequentially in one setting of the workpiece. Complete processing of the shaft workpiece on a screw-cutting lathe can be carried out only with two workpiece settings in the centers of the machine, since after processing the workpiece on one side (setting BUT) it must be unfastened, turned over and installed in a new position (installing B) for processing on the other side. In the case of turning the workpiece without removing it from the machine, it is necessary to indicate the angle of rotation: 45 o, 60 o, etc.

The installed and fixed workpiece, if necessary, can change its position on the machine relative to the tool or working bodies of the machine under the influence of linear movement devices or rotary devices, taking a new position.

position is called each separate fixed position occupied by an invariably fixed workpiece or an assembled assembly unit together with a fixture relative to a tool or a fixed part of the equipment when performing a certain part of the operation. When machining a workpiece, for example, on a turret lathe, the position will be each new position of the turret. When processing on multi-spindle automatic machines and semi-automatic machines, the invariably fixed workpiece occupies different positions relative to the machine by rotating the table, which sequentially brings the workpiece to different tools.

Technological transition- a completed part of the technological operation, performed by the same means of technological equipment under constant technological conditions and installation. Technological transition, therefore, characterizes the constancy of the tool used, the surfaces formed by processing or connected during assembly, as well as the invariance of the technological regime.

For example, technological transitions will be making a hole in the workpiece when processing with a twist drill, getting a flat surface of a part by milling, etc. Sequential processing of the same hole in the gearbox housing with a boring cutter, countersink and reamer will consist of three technological transitions, respectively, since a new surface is formed during processing with each tool.

In the turning operation, the scheme of which is shown in Fig. 11a, two technological transitions are performed. Such transitions are called simple or elementary. The set of transitions, when several tools are involved in the work at the same time, is called combined transition(Fig. 11b). In this case, all tools work with the same feed and speed. In the case when there is a change in sequentially machined surfaces with one tool with a change in cutting conditions (speed when processing on hydrocopy machines or speed and feed on CNC machines), with one working stroke of the tool, difficult transition.

Technological transitions in this case can be performed sequentially (Fig. 11, a) or in parallel-series (Fig. 11, b).

When processing workpieces on CNC machines, several surfaces can be sequentially processed by one tool (for example, a cutter) when it moves along a path specified by the control program. In this case, we say that the specified set of surfaces is processed as a result of executing instrumental transition.

Examples of technological transitions in assembly processes can be works associated with the connection of individual parts of the machine: giving them the required relative position, checking the achieved position and fixing it with fasteners. In this case, the setting of each fastener (for example, a screw, bolt or nut) should be considered as a separate technological transition, and the simultaneous tightening of several nuts using a multi-spindle wrench should be considered as a combination of technological transitions.

A technological operation, depending on the organization of the technological process, can be carried out on the basis of concentration or differentiation of technological transitions. With the concentration of transitions, the structure of the operation includes the maximum possible number of technological transitions under given conditions. This organization of the operation reduces the number of operations in the process. In the limiting case, the technological process may consist of only one technological operation, including all the transitions necessary for the manufacture of the part. When differentiating transitions, they tend to reduce the number of transitions included in the technological operation. The limit of differentiation is such a construction of the technological process, when each operation includes only one technological transition.

A characteristic feature of the technological transition in any processes (except hardware ones) is the possibility of its isolation at a separate workplace, i.e. isolating it as a stand-alone operation. In the case of a single-transition operation, the concept of an operation may coincide with the concept of a transition.

When organizing the processing process according to the principle of differentiating the construction of an operation (rather than a transition), the technological process is divided into one-, two-transitional operations, subject to the duration of the release cycle. If operations (for example, gear hobbing, spline milling) go beyond the limits of the release cycle in duration, then backup machines are installed. Therefore, the limit of differentiation is the release cycle.

The principle of concentration of operations is divided into the principle of parallel concentration and sequential. In both cases, a large number of technological transitions are concentrated in one operation, but they are distributed among positions in such a way that the processing time for each operation is approximately equal to or less than the release cycle. The time limit for the operation will be determined by the longest time by position. According to the principle of sequential concentration, all transitions are performed sequentially, and the processing time is determined by the total time for all transitions.

Technological transition during cutting may consist of several working moves.

Under working stroke understand the completed part of the technological transition, consisting of a single movement of the tool relative to the workpiece, accompanied by a change in the shape, dimensions, surface quality or properties of the workpiece. The number of working moves performed in one technological transition is chosen based on the provision of optimal processing conditions, for example, reducing the depth of cut when removing significant layers of material.

An example of a working stroke on a lathe is the removal of one layer of chips with a cutter continuously, on a planer - the removal of one layer of metal over the entire surface, on a drilling - drilling a hole to a given depth.

Working strokes take place in those cases when the allowance exceeds the possible depth of cut and it has to be removed in several working strokes.

When repeating the same work, for example, drilling four identical holes in series, there is one technological transition performed in 4 working steps; if these holes are made simultaneously, then there are 4 combined working strokes and one technological transition.

The operation also includes elements associated with the implementation of auxiliary movements and necessary for the implementation of the technological process. These include auxiliary transitions and tricks.

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 or properties of the surface, but are necessary to complete the technological transition.

Auxiliary transitions include, for example, fixing a workpiece on a machine or in a fixture, changing a tool, moving a tool between positions, etc. For assembly processes, transitions can be considered auxiliary when installing a base part on an assembly stand or in a fixture on a conveyor, moving attached parts to it and etc.

Auxiliary moves and techniques are also necessary to perform a technological operation.

Auxiliary move- the completed part of the technological transition, consisting of a single movement of the tool relative to the workpiece, necessary for the preparation of the working stroke.

Under reception understand the complete set of actions of the worker used in the performance of the transition or part of it and united by one purpose. For example, the auxiliary transition "set the workpiece in the fixture" consists of the following steps: take the workpiece from the container, install it in the fixture, fix it.

Auxiliary moves and techniques are taken into account when studying the costs of auxiliary time for performing an operation.

Any technological process takes place in time. The interval of calendar time from the beginning to the end of any periodically repeating technological operation, regardless of the number of simultaneously manufactured or repaired products, is called technological operation cycle .

The preparation of technological equipment and technological equipment for the performance of a technological operation is called adjustment . Setup includes setting up a fixture, switching speed or feed, setting a set temperature, etc. Additional adjustment of technological equipment and (or) equipment in the process of work to restore the values ​​​​of parameters achieved during adjustment is called adjustment .

3.2 Technology transition

Technological transition is called the completed part of the technological operation, performed by the same means of technological equipment with constant technological modes and installation. If the tool was changed during the turning of the roller, then the processing of the same surface of the workpiece with this tool will be a new technological transition (Figure 3.3). But the tool change itself is an auxiliary transition.

Figure 3.3 - Scheme of technological transition

An auxiliary transition is a completed part of a technological operation, consisting of human and (or) equipment actions that are not accompanied by a change in the properties of the object of labor, but are necessary to complete the technological transition. Transitions can be combined in time due to the simultaneous processing of several surfaces, i.e. they can be carried out sequentially (roughing, semi-finishing, finishing turning of a stepped shaft or drilling four holes with one drill), parallel (turning a stepped shaft with several cutters or drilling four holes at once four drills) or parallel-sequential (after turning the stepped shaft simultaneously with several cutters, simultaneous chamfering with several chamfering cutters or drilling four holes in series with two drills).

Installation - a part of the technological operation, performed with the unchanged fixing of the workpieces being processed or the assembled assembly unit. Turning parts to any angle is a new setting. If the roller is first turned in a three-jaw chuck with one setting, and then it is turned over and turned, then this will require two settings in one operation (figure 3.4).

Figure 3.4 - Scheme of the first (a) and second (b) installation

3.3 Position

The workpiece installed and fixed on the rotary table, subjected to drilling, reaming and countersinking, has one setup, but with the rotation of the table it will take a new position.

A position is a fixed position occupied by a rigidly fixed workpiece or an assembled assembly unit together with a fixture relative to a tool or a fixed part of the equipment when performing a certain part of the operation. On multi-spindle machines and semi-automatic machines, the workpiece, with one fixing it, occupies different positions relative to the machine. The workpiece is moved to a new position along with the clamping device (figure 3.5).

When developing a technological process for processing workpieces, it is preferable to replace setups with positions, since each additional setup introduces its own processing errors.

Figure 3.5 - Scheme of changing workpiece positions on a multi-spindle machine

3.4 Working and auxiliary stroke

The working stroke is the completed part of the technological transition, consisting of a single movement of the tool relative to the workpiece, accompanied by a change in the shape, dimensions, surface quality and properties of the workpiece. The working stroke usually accompanies the continuous processing of one layer of the workpiece, for example, on a lathe - processing the shaft per pass, on a planer - one movement of the cutter during cutting.

Auxiliary stroke is the completed part of the technological transition, consisting of a single movement of the tool relative to the workpiece, necessary to prepare the working stroke. For example, when rough turning a shaft, the cutter returns to its original position, making an auxiliary stroke.

3.5 Reception

A technique is a complete set of human actions used in the performance of a technological transition or part of it and united by one purpose. Usually, the reception is an auxiliary action of the operator when controlling the machine (manually), measuring the workpiece. Receive element - pressing a button, moving a handle, etc.

Important characteristics of the technological process and operation are the cycle, technological operation, tact and rhythm of release.

3.6 Cycle, beat and rhythm release

The cycle of a technological operation is a calendar time interval from the beginning to the end of a periodically repeating technological operation, regardless of the number of simultaneously manufactured products.

A tact is a time interval through which the release of products or blanks of certain names, sizes and designs is periodically performed.

The release rhythm is the number of products or blanks of certain names, sizes and designs produced per unit of time.

It is desirable that the time spent on the execution of one operation be equal to the release cycle time or a multiple of it. Such a correction of the time spent on the operation is achieved by varying degrees of concentration of operations, the use of optimal processing modes, the reduction of auxiliary time due to multi-place devices, automation of loading, transportation, the use of more high-performance equipment, parallel operation on the same type of backup machines, etc.