Technological transition refers to the completed part of a technological operation performed by the same means of technological equipment under constant technological conditions and installation. If a tool was changed when turning the roller, then processing the same surface of the workpiece with this tool will be a new technological transition (Fig. 1.6). But the tool change itself is an auxiliary transition.

Rice. 1.7. Sketch of turning operation

a – simple transitions;

b – difficult transition

2.2.2. Auxiliary transition refers to the 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), in parallel (turning a stepped shaft with several cutters or drilling four holes at once four drills) or parallel-sequentially (after turning a stepped shaft simultaneously with several cutters, simultaneous chamfering with several chamfering cutters, or drilling four holes sequentially with two drills).

Installation

Installation- part of the technological operation performed with unchanged fastening of the workpieces being processed or the assembled assembly unit. Rotating parts to any angle is a new installation. 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 (Fig. 1.7).

2.2.4. Position. A workpiece installed and secured on a rotary table, subjected to drilling, reaming and countersinking, has one setting, but with the rotation of the table it will take a new position.

Position is a fixed position occupied by a rigidly fixed workpiece or assembled assembly unit together with a device relative to a tool or a stationary piece of equipment when performing a certain part of the operation. On multi-spindle and semi-automatic machines, the workpiece, when it is secured, occupies different positions relative to the machine. The workpiece moves to a new position together with the clamping device (Fig. 1.8).

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

Technological operation- completed part of the technological

process performed at one workstation. For surgery

the time standard is determined and the operation is thus

unit for planning the volume of work and jobs in the workshop

A technological operation is the main structural unit of a technological process. This part of the technical process associated with the processing of one or more simultaneously processed workpieces, by one or more simultaneously working workers, at one workplace and continuously.

Continuity condition operations means performing the work provided for by it without moving on to processing another product or the same product, but at a different workplace. For example, processing a stepped roller in the centers on a lathe represents one technological operation if it is performed in the following sequence: install the workpiece in the centers, grind the roller at one end, remove the workpiece, reinstall the clamp and reinstall the workpiece in the centers, grind the roller from the other end.

Work on a roller similar in content can be performed in two operations:

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

Attach the clamp to 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 for processing other workpieces of the batch (i.e., first all workpieces are processed from one end, and then everything from the other). The example given shows that the composition of the operation is established not only on the basis of purely technological considerations, but also taking into account organizational expediency.

A technological operation is the basic unit of production planning and accounting. Based on the operations, the labor intensity of manufacturing products is determined and time standards and prices are established.

Technological transition

operations performed by the same means

technological equipment with constant technological

modes and installation.

Auxiliary transition - completed part of the technological

operations consisting of human and/or/ equipment actions,

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

necessary to complete a technological transition /example -

installing a workpiece, changing tools, etc./. Auxiliary

transitions are not recorded in the process map. At

simultaneous processing of several

transition on surfaces is called combined. Often found

operations consisting of just one technological transition.

Working stroke - 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 properties of the workpiece.

Technological operation is a completed part of a technological process performed at one workplace. Operation is the main element of production planning and accounting.

This part of the process is performed:

– over a specific workpiece;

– one or a group of workers;

– continuously;

- at one workplace.

The operation can be performed on separate technological equipment (machine) in conventional production or on an automatic line, which is a complex of technological equipment. Such equipment is connected by a unified transport system with technological equipment and a unified management and control system.

Main elements of the technological operation:

1. Installation is a part of a technological operation that is performed with constant fastening of processed workpieces or assembled assembly units.

2. Position - a fixed position occupied by a permanently fixed workpiece or assembled assembly unit together with a device relative to a tool or a stationary piece of equipment to perform a certain part of the operation.

3. Technological transition– a completed part of a technological operation, performed by the same means of technological equipment under constant technological conditions and installation.

4. Working stroke – a 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, size, quality and properties of the processed surface.

5. 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, quality and properties of the processed surfaces, but are necessary to complete the technological transition.

6. Auxiliary move– a completed part of a technological transition, consisting of a single movement of the tool relative to the workpiece, which is not accompanied by a change in the shape, size, quality and surface properties of the workpiece, and the working stroke necessary to perform.

7. Setup – preparation of technological equipment and accessories for performing a technological operation. Adjustment includes installation of the fixture on the machine, alignment to the size of the cutting tool, etc.

8. Adjustment – ​​additional adjustment of technological equipment or technological equipment when performing a technological operation to restore the parameters achieved during adjustment.

9. Technological equipment– these are means of technological equipment in which, in order to perform a certain part of the technological process, materials or workpieces, means of influencing them, as well as technological equipment are placed.

10. Technological equipment– means of technological equipment that complement technological equipment for performing a certain part of the technological process.

3.2 Technological transition

A technological transition is a completed part of a technological operation, performed by the same means of technological equipment under constant technological conditions and installation. If a tool was changed when turning the roller, then processing 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 - Technological transition diagram

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), in parallel (turning a stepped shaft with several cutters or drilling four holes at once four drills) or parallel-sequentially (after turning a stepped shaft simultaneously with several cutters, simultaneous chamfering with several chamfering cutters, or drilling four holes sequentially with two drills).

Installation is a part of a technological operation performed with unchanged fastening of the workpieces being processed or the assembly unit being assembled. Rotating parts to any angle is a new installation. If the roller is first turned in a three-jaw chuck in one setting, and then it is turned over and turned, 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

A workpiece installed and secured on a rotary table, subjected to drilling, reaming and countersinking, has one setting, 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 assembled assembly unit together with a device relative to a tool or a stationary piece of equipment when performing a certain part of the operation. On multi-spindle and semi-automatic machines, the workpiece, when it is secured, occupies different positions relative to the machine. The workpiece moves to a new position together with the clamping device (Figure 3.5).

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

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

3.4 Working and auxiliary stroke

A working stroke is the completed part of a technological transition, consisting of a single movement of the tool relative to the workpiece, accompanied by a change in the shape, size, 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 a shaft per pass, on a planer - one movement of the cutter during cutting.

An auxiliary stroke is a completed part of a 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 when performing a technological transition or part of it and united by one purpose. Typically, the technique is an auxiliary action of the operator when operating the machine (manually), measuring the workpiece. Reception 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 of release

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

A takt is the time interval through which products or blanks of certain names, standard sizes and designs are periodically produced.

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

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

§ 22. STRUCTURE OF THE TECHNOLOGICAL PROCESS.

Operations, settings, positions, transitions, working and auxiliary moves and auxiliary transitions.

The technological process is divided into operations, settings, positions, transitions, working and auxiliary moves and auxiliary transitions.

A technological operation is a completed part of a technological process, performed at one workplace and covering all actions of a worker and equipment performed with one or more simultaneously processed parts. Machining a different part or another surface in a batch of identical parts is considered a new operation. For example, grinding one slab on one surface grinding machine on both sides is performed in one operation. If a batch of slabs is ground one slab at a time, first on one side and then on the other, then two operations are performed.

A setup is a part of a technological operation performed while permanently securing a workpiece being processed or a group of workpieces being simultaneously processed. Removing a part from the machine and then securing it is considered a new installation.

A position is a fixed position occupied by a permanently fixed workpiece together with a fixture relative to a tool or a stationary piece of equipment to perform a certain part of the operation.

A technological transition is a completed part of a technological operation, characterized by the constancy of the tool used and the surfaces formed by the processing. Therefore, the transition from processing one surface of the workpiece to another surface is the next transition.

A working stroke is a completed part of a technological transition, consisting of a single movement of the tool relative to the workpiece, accompanied by a change in the shape, size, roughness or properties of the workpiece.

An auxiliary transition is a completed part of a technological operation, consisting of actions of a person and equipment or equipment alone, which are not accompanied by a change in the shape, size and roughness of surfaces, but are necessary to complete the technological transition (starting the machine, stopping the machine, turning on the feed, etc.) .

An auxiliary stroke is a completed part of a technological transition, consisting of a single movement of the tool relative to the workpiece, not accompanied by a change in the shape, size, surface roughness or properties of the workpiece, but necessary to complete the working stroke.