Rice. 3.4. Symbols on the disassembly diagram of the object:

a - details; b - dismantling groups; V - simultaneous removal of two parts

during disassembly

In the diagram, the rectangles characterizing the assembly units are recommended to be placed on the left, and the details on the right along the line. The beginning of the disassembly scheme is the assembly unit, and the end is the base part.

The block diagram of disassembly of the assembly together with its sketch is presented on the sheet of the graphic part of the project. An example of the design of the technological scheme of disassembly is shown in Figure 3.5.

When developing technological processes for repairing machines and restoring parts, the technical characteristics of the product (defects, dimensions, configuration and accuracy indicators), as well as the specific conditions of repair production, first of all, determine the solution of the main tasks of designing these processes:

determination of the type of production (single, serial, mass);

development of the main schemes of routes for the restoration of parts;

selection of reference surfaces, assessment of accuracy and reliability;

identification of defects to be eliminated, determination of permissible, repair, limit values ​​for the dimensions of the working surfaces of parts and development of repair drawings;

selection of ways to eliminate defects based on structural and technological characteristics, indicators of the physical and mechanical properties of parts and technical and economic indicators of methods for their restoration;

development of a technological route for restoring a part;

development of technological operations (rational construction and selection of the structure of technological operations; establishment of a rational sequence of transitions in operations; selection of technological equipment that ensures optimal performance while ensuring the required quality; calculations of optimal modes of basic technological operations and determination of technical time standards);

selection of a rational option for the technological process of restoring parts.

The technological process of restoring a part, as a rule, is presented in the form of route cards (forms 2 and 1b according to GOST 3.1118) and operational cards (form 3 according to GOST 3.1404). The operational card of technical control is drawn up in accordance with GOST 3.1502 (forms 2 and 1b). At the same time, operational cards must contain sketch cards drawn up in accordance with GOST 3.1105 (forms 7 and 7a). The procedure for issuing technological documentation for the restoration of units, assembly units and machine parts is described in detail in the second section of the textbook (see paragraph 2.3.2).

Depending on the scale of repair production (single, small-scale, serial, mass), the following forms of organization of technological processes for the restoration of parts are common:

defective technology (the technological process is developed for each defect);

route technology (the technological process is developed for a complex of defects of a certain combination that occur on the details of this name);

Group technology (a technological process is developed for a group of similar parts of a certain class, in accordance with the typification of technological processes).

Defective technology is characterized by the fact that worn parts are formed in small batches to eliminate each individual defect. After the defect is eliminated, such batches disintegrate. The picking of parts takes place only by name, without taking into account their namesake and existing defects. At the same time, the launch of large batches of parts and the use of specialized equipment, fixtures and tools becomes irrational. The passage of parts through the shops and areas becomes more complicated, and the duration of the recovery cycle increases significantly. This form of organization is used only in enterprises with small volumes of recovery.

Route technology is characterized by the fact that a batch of parts assembled for a certain technological route does not fall apart in the process of its restoration, but is preserved from the beginning to the end of the route. With route technology, a technological process is developed to eliminate a certain combination of defects.

Route technology has the most efficient (profitable) sequence of technological operations with the shortest route for parts to pass through workshops and sections, since the importance and role of the method of restoring parts increase, since the content of the route is determined precisely by the method of restoring parts. Since the parts have a variety of defects that can be eliminated in various ways, the combination of defects cannot be covered by one route with one technological process. Obviously, each combination of defects (each route) requires its own technological process. The route number is set at the detection site. The number of routes should be kept to a minimum.

Changing the number of technological recovery routes significantly affects the efficiency of production.

A large number of routes complicates planning and accounting for production, complicates technological documentation, and also requires an increase in storage space. Therefore, the use of route technology is expedient for centralized restoration of parts and in large specialized enterprises.

Reducing the number of routes, on the contrary, reduces the time for completing a production batch of parts, and, consequently, reduces the need for production space. However, in this case, parts with different combinations of defects are combined into each technological route, which means that parts with “non-existent” defects are included in the route.

When determining the content and number of routes based on the analysis of statistical data on the study of wear and combinations of defects, the following provisions are guided:

Rice. E.5. An example of the design of a technological scheme for disassembling the input shaft of the gearbox

the combination of defects in the route with which the parts are sent for restoration should be natural;

the number of routes for each repaired part should be minimal (two, three, but not more than five);

in the route, the technological interconnection of defects should be provided according to the methods for their elimination;

restoration of parts along this route should be economically feasible.

In the absence of this information, a combination of defects is accepted based on the following main features of combining natural combinations of defects into routes:

the functional interconnection of the surfaces of the part requires the inclusion in the same route of defects, the elimination of which separately does not provide the necessary accuracy in restoring the design geometry of individual surfaces of the part (coaxiality, parallelism, perpendicularity);

defects are included in the same route, when one of them is eliminated, the other one is automatically (by itself) eliminated;

defects of adjacent surfaces, for the elimination of which a common technological process can be applied, are also included in the same route;

it is recommended to combine defects and their combinations into one route, the elimination of which is carried out using the same technology, as well as defects that can be eliminated in various ways, but at common workplaces;

mutually exclusive defects are not allowed in the same route;

Associated defects should be included in each route.

A related defect is a defect for which

no special equipment is required, and it can be easily eliminated during locksmith operations (for example, threading, straightening, etc.).

In route technology, the wear of the same surface is taken as several defects if, for different wears, different methods of their elimination can be assigned, for example, the “crankshaft journal wear” defect. In this case, such a wear of the crankshaft journal is taken as one defect, in which it is possible to apply regrinding of the neck to a repair size, and another is taken to be wear of the crankshaft journal to a size at which metal build-up is already required (surfacing, sintering, ironing, etc. ). In this case, the defects will be mutually exclusive.

In the explanatory note, the distribution (combination) of defects along the routes is presented in the form of a map (Table 3.12).

As an example, Figure 3.6 shows a diagram of the process for restoring the axis of the track roller with three technological routes. At the same time, parts with a combination of defects X 1.2.3 , X 1.2 and X 2.3 are excluded due to the high labor intensity and high cost of restoration.

Table3.12 - Map of a combination of shaft defects along the routes

Rice. 3.6. Scheme of the technological process of restoring the axis of the track roller with three technological routes

Thus, out of 1000 parts accepted for restoration, it is economically feasible to restore only 49.5 % or 495 parts, 387 parts will not require restoration, and 118 parts will be sent to scrap metal due to the economic inexpediency of their restoration.

Labor activity in the OAT requires its own organization, which is understood as an ordered system of interaction between workers, their groups and departments to achieve their goals. It is determined by the type of organization and the number of serviced and repaired vehicles. If a motor transport complex or cooperative organization engaged in road transport is considered, then the organization of maintenance and repair processes will be additionally influenced by the mode of operation of vehicles. As a rule, it is determined by the features of the existing transport process and basically corresponds to the recommendations of ONTP 01-91. The recommended operating time of vehicles (Table 2.1) should be at least 10.5 hours, the number of working days per year should be at least 255.

The mode of operation of the production units of the technical service must correspond to the mode of operation of vehicles (Table 2.2). The experience of modern ATO shows that when vehicles are operated 365 days a year, the production zones of the EO and maintenance should work the same amount, and the number of days of operation per year of zones D-1, D-2, TO-1 and TO-2 may be less . The two-shift operation is used only in large transport organizations, and the three-shift operation is currently not used at all. For car service and car repair organizations, the operating hours of production units can be adopted, as for motor vehicles, but taking into account the daily receipt of cars for maintenance and repair. The number of days of work in a year for them does not exceed, as a rule, 305 days.

The end of the table. 2.2

The most difficult will be the organization of the production process in an integrated motor transport organization of medium or large capacity. This is due to the fact that it is necessary to organize and link the processes of transport and technical operation. Reception and release of cars is carried out at the control and technical point (KTP). When carrying out maintenance and repairs, the main technological processes are cleaning and washing (CWR), performed at EO, D-1, D-2, TO-1, TO-2 and TR. On the general scheme of the production process of maintenance and repair (Fig. 2.1), the places of their implementation and possible routes for the movement of vehicles are indicated. A gas release post is provided if the organization operates gas-cylinder vehicles (GBV). This scheme is focused on the use of diagnostics in almost all technological processes. One or more waiting areas can be used to smooth out the uneven arrival of cars in production areas.

To ensure the continuity of technological processes associated with the repair of vehicles and their units in the TR zone and repair areas, a complex for the preparation of

Rice. 2.1. Scheme of organization of maintenance and repair processes with diagnostics in integrated and cooperative ATO production (CPP). It is entrusted with the functions of timely delivery of the necessary spare parts and materials to the posts; receiving, storing and issuing units, assemblies and parts repaired and manufactured on their own, as well as received from car repair organizations. Therefore, it includes an intermediate warehouse. Driving cars in the zones is carried out by drivers-drivers of the same complex.

Maintenance and repair of garage equipment, technological equipment and tools is carried out by the Chief Mechanic Department (CMO). In addition, it is entrusted with the functions of manufacturing the necessary non-standard equipment, tooling and tools.

As seen in fig. 2.1, the execution of work is assigned to structural units that must have their own production base: buildings, structures, premises, technological equipment, equipment, etc. (Fig. 2.2). A large number of structural units, main and auxiliary premises, a variety of types of work performed and a significant number of their performers sets the task of organizing and interconnecting all ongoing technological processes, organizing the work of production zones and sites, their structural units - work posts and jobs.

The considered schemes may be different for motor transport organizations operating on the principles of cooperation and specialization of production. For example, the operational branch of ATO, which is mainly engaged in the organization of the transport process, may have a production base that ensures the implementation of simple types of technical actions: SW, TO-1 and simple repairs (Table 2.3). ATO production branches, on the contrary, can deal with complex types of maintenance and repair.

In each specific case, it is advisable to justify the accepted scheme of the production process to ensure the operability of vehicles. The simplest method to justify the legality of the use of certain technological processes and relevant production units in ATO is the calculation of the production program for maintenance and repair and the number of work performers.

Rice. 2.2.

medium or high power

Table 2.3

Variants of production processes for maintenance and repair of various ATO

If the estimated number of performers of the work of the section is less than 0.5, then, most likely, it is not advisable to create it, except for the case when this section can be combined with another, also underloaded. The sites grouped into one subdivision should have a similar nature of work and similar working conditions in terms of fire, construction, sanitary, technical and other standards. OAT work experience shows that it is allowed to group the engine, aggregate, metalwork-mechanical, electrical and fuel sections into a mechanical department; forging and spring, welding, tin and copper sections - to the thermal department. Body, reinforcing, wallpaper and carpentry areas can be combined into a body compartment. Within the framework of these departments, it is allowed to create smaller departments: welding and tinsmithing, carpentry and wallpaper, aggregate-motor, etc.

For a more accurate justification, it is necessary to evaluate the effectiveness of the creation and operation of such a department in a particular ATO. The components of this complex effect will be the following partial effects: economic, technical, technological, environmental, social, etc. All of them are different, but interconnected and can be reduced to a cost form. The simplest are statistical methods for assessing economic efficiency, which consist in assessing the total profit, which is calculated as the difference between the total cost results and costs incurred during the implementation of the project. Most often, these cost indicators are given to one year of work. In relation to the production unit created in ATO, they can be written:

Where C mi- current (operational) costs for the maintenance of the i-th production unit; E n - normative coefficient of reduction to the year of capital investments (taken 0.13-0.15); KB? - capital investments for the creation of the i-th production unit.

The annual operating costs for the maintenance of the production unit include the wages of maintenance workers, depreciation deductions for the repair and replacement of equipment in it, operating costs for electricity, water, heat, compressed air, etc.

Capital costs are determined by the sum of the costs of acquiring and installing equipment, as well as the cost of building a production unit.

You can not create a production unit, then this amount of annual work T? will be performed in other organizations on a paid basis with approximate cost costs

Where sj- the cost of a standard hour for the performance of this type of work; (3 is a coefficient that takes into account transportation costs for the delivery of a car or its units for maintenance or repair (may be in the range of 1.01-1.15).

If the difference between the costs of C 2 and C drg is greater than or equal to zero, then the creation of a production unit will be economically unprofitable and vice versa. Given that the methodology is approximate, since it does not take into account all types of costs, the cost coefficient can be recommended as the final criterion for making a decision:

If the value of the cost coefficient is greater than -OD (approximately a ten percent error is laid, possibly allowed in the calculations), the creation of a production unit will be inappropriate.

If the issue of using the ?-th unit is resolved as part of its reconstruction, then capital investments are calculated according to the formula

where /C reg - capital investments required for the reconstruction of the ?-th production unit; C w - non-amortized cost of withdrawn fixed assets; C r - the cost of selling the withdrawn fixed assets; DP rekg - possible losses of the organization's profit during reconstruction; З lg - liquidation costs.

Another criterion that makes it quite easy to determine the feasibility of creating a specific production unit can be the payback period, which is understood as the period of time during which capital investments will be returned with income from the project. Approximately, it can be defined as the ratio of capital investments to the planned average annual income. More complex (dynamic) methods can also be used, in which expenses and incomes at different times lead to one point in time by means of their discounting.

Vehicle reliability data, systematized in the form of appropriate recommendations (maintenance and repair system, types of maintenance and repair, maintenance frequency and unit resource standards, lists of maintenance and repair operations, etc.) determine what needs to be done to ensure the vehicles work. These technical actions can be performed in various ways (sequence, equipment, personnel, etc.), i.e., using the appropriate technology that establishes how the necessary level of technical condition of vehicles should be ensured during maintenance and repair.

In general terms, technology (from the Greek techne art, skill, skill + logos concept, teaching, science, field of knowledge) is a set of knowledge about the ways and means of changing or providing a given state, form, property or position of the object of influence. With regard to TEA, the goal of the technology is to provide a given level of vehicle or fleet performance in the most efficient way.

A technological process is a certain set of influences exerted systematically and consistently in time and space on a specific object. In the technological processes of maintenance and repair, the objects of influence (car, unit, system, assembly, part, connection or material), place, content, sequence and result of the actions carried out, their labor intensity, requirements for equipment, personnel qualifications and working conditions are defined.

The set of technological processes is the production process of the enterprise. Optimization of technological processes allows, in relation to specific production conditions, to determine the best sequence of work, ensuring high labor productivity, maximum safety of parts, an economically justified choice of mechanization and diagnostics

The completed part of the technological process by one or more performers at one workplace is called a technological operation (more often an operation). The part of the operation characterized by the immutability of the equipment or tool is called the transition. The transitions of the technological process can be divided into the movements of the performer. The combination of these movements is a technological technique.

Technological equipment is tools for the production of maintenance and repair of vehicles used in the performance of work from the beginning to the end of the technological process. The equipment is divided into specialized, manufactured directly for the purposes of the technical operation of vehicles (washing machines, lifts, diagnostic devices, lubricating refueling devices, etc.), and general purpose (metal-cutting and woodworking machines, presses, beam cranes, etc.).

The first group includes equipment and devices that provide convenient access to units, mechanisms and parts located below and on the side of the vehicle. This includes inspection ditches, overpasses, lifts, tippers, garage jacks. The second group includes equipment for lifting and moving units, components and mechanisms of the car. These are mobile cranes, electric hoists, beam cranes, cargo trolleys and conveyors.

According to the purpose, technological equipment is divided into hoisting inspection, hoisting and transport, specialized for maintenance and specialized for TR

The third group is equipment designed to perform specific maintenance operations: cleaning, washing, fixing, lubricating, diagnostic, adjusting, refueling. The fourth group is equipment designed to perform technological operations of TR: dismantling, assembly, metalwork, electrical, bodywork, welding, copper, tire fitting, vulcanization, etc.

Separate types of the most common equipment are presented in the following slides, with the types of work for which this equipment is intended. Technological equipment - tools and means of production added to technological equipment to perform a certain part of the technological process.

CLEANING AND WASHING WORKS Are intended for removal of pollution of a body, salon, knots and units of cars, including for creation of favorable conditions at performance of other works MOT and TR; maintaining the required sanitary condition inside the car body and interior; protection of the paintwork from the effects of the external environment; maintaining the exterior surfaces of the body in a condition that meets aesthetic requirements.

Control-diagnostic and adjustment works They are designed to determine and ensure the compliance of the vehicle with traffic safety requirements and the impact of the vehicle on the environment, to assess the technical condition of units and assemblies without disassembling them.

There are: bench diagnostics (aggregates, systems); built-in diagnostics, when information is displayed on the dashboard; express diagnostics; element-by-element diagnostics; electronic scanning, that is, a survey of special sensors that record the parameters of the processes occurring during the operation of the car.

Ditches and overpasses belong to lifting and transport equipment and constitute a subgroup of lifting and inspection equipment. They can carry out work from the bottom and side of the car. The length of the ditch should be 0.5 0.8 m longer than the length of the car. Depth for cars 1.4 1.5 m, for trucks and buses 1.2 1.3 m. The entrance to the ditch should be located outside the working area. For the safe entry of vehicles, ditches are framed with guide flanges on the side with a height of no more than 15 cm and a bump stop on the side of the entrance; stops are placed at the end of the dead-end ditch from the side of the open trench.

Narrow ditches are made with a width of no more than 0.9 m with reinforced concrete flanges and no more than 1.1 m with metal ones. The depth of the side ditches is 0.8 0.9 m, the width is not less than 0.6 m. Parallel narrow ditches are connected by an open trench or tunnel 12 m wide and up to 2 m deep. ditches on the side of the trench install walkways. trenches

Wide ditches are larger than the dimensions of the serviced vehicle by 1.01.2 m. Removable ladders are provided for side work. Lamps are installed in the niches of the walls of the ditches. Ditches are equipped with exhaust or supply ventilation systems. The latter is also used for heating.