Organization of a workshop for repair of truck engines in Bender and Tiraspol on the basis of OJSC Bender Automobile Assembly Plant

Contents

Introduction

1. Analysis of production activities of the enterprise

1.1. History of the development of the Bender Automobile Assembly Plant

1.2. Enterprise Structure

1.3. Main types of economic activity, types of manufactured products

1.4. Technical and economic indicators of the enterprise

1.5. Analysis of engine repair technology organization at the enterprise

1.6. The organization to îíòðîyoya êà÷åñòâà ðåìîíònyh of works at the enterprise

1.7. Rationale of thesis project topic

 

 

2. Settlement and Organizational Section

2.1. Rationale and Selection of Production Flow Chart

2.2. Justification and determination of workshop production capacity

2.3. Calculation of time funds

2.4. Calculation of production areas. General layout of the production building

2.5. Development of cargo flow schedule. PTM selection

 

3. Process Section

Design and technological features of KamAZ engine cylinder block

3.2. Characteristics of cylinder block defects

3.3. Analyze and select existing cylinder block recovery methods

3.4. Justification of recovery process selection

3.5. Recovery technology of landing holes, cylinder block of KamAZ engine

3.6. Development of the recovery process

 

 

 

4. Design Section

4.1. Rationale for Design Development

4.2. Installation and operating principle of the bench

4.3. Process and design calculations of the bench

5. Production and environmental safety

5.1. Occupational safety at the enterprise

5.2. Fire fighting measures

5.3. Organizational arrangements for environmental protection

5.4. Occupational Safety Instruction for Bench Worker 

for ICE repair

5.5. Calculation of energy resources of the designed workshop

 

6. Project Feasibility Study

6.1. Technical and economic indicators of the engine repair shop

6.2. Calculation of economic indicators of design development

Conclusion

List of literature used

Application

Summary

The theme of the diploma project: "Organization of a workshop for the repair of truck engines in Bender and Tiraspol on the basis of Bender Automobile Assembly Plant OJSC"

The project was completed at the Department of Automobile Transport

Performer: Syrbu Alexander Mikhailovich

Head: Art. Teacher Kotomchin Alexey Nikolaevich

The explanatory note includes 95 pages, 10 sheets of the A-1 format of the graphic part and 30 literary sources are used.

This diploma project analyzed the production activities of Bendery Automobile Assembly Plant OJSC, the state and indicators of the enterprise. The objectives and objectives of the truck engine repair shop are justified.

Based on the composition of the fleet of trucks in Bender and Tiraspol, which can contact the company, the scope of work of the engine repair workshop, reduced to one engine brand - KamAZ-740.1, was determined and the engine repair workshop was designed with equipment placement.

In the process section, the process of restoring the KamAZ740.1 cylinder block was developed.

The design section proposes the design of a stand for repairing the cylinder block, which will increase the quality of repair and reduce the cost of repair work in general for the engine.

Proposed measures for labor protection and environmental protection during repair of engines in the workshop.

Investments in the organization of the engine repair workshop will amount to 1942130 rubles, the payback period of capital investments is 3 years. A technical and economic assessment was given from the introduction of design development, which will amount to 12863.74 rubles, the payback period is 0.5 years.

Thesis Project Assignment

1. The theme of the diploma project: "Organization of a workshop for the repair of truck engines in Bender and Tiraspol on the basis of Bender Automobile Assembly Plant CJSC."

2. Project Input:

Data on pre-diploma practice, GAI data on the quantitative composition of trucks in Bender and Tiraspol.

3. Content of the calculation and explanatory note.

3.1. Enterprise Analysis

3.2. Organizational section.

3.3. Process section.

3.4. Design section.

3.5. Production and environmental safety.

3.6. Technical and economic efficiency of the project.

4. Graphic part.

Analysis of production activities of the enterprise. Schedule of distribution of engine repair scope. Production building of engine repair shop. Part Repair Flow Sheet. Analyze existing constructs. General view of the structure. Assembly drawing. Details. Diagrams and maps. Economic indicators of the diploma project.

Introduction

Overhaul is one of the main elements of the system of measures that ensure the operability of road transport rolling stock. Overhaul is the repair performed at specialized enterprises with the complete disassembly of the car. Such enterprises include, first of all, mechanical repair plants (RMZ), designed for major repairs of complete machines and units.

The technological process is the basis of the organization of modern repair production and is a set of operations performed in a certain sequence in order to restore the serviceability and operability of the repaired objects. The developed process allows you to establish the types, scope of work and labor intensity of repairs, the nomenclature and amount of equipment, the required labor force, the size of production areas, the type and number of vehicles and the cost of repairs.

During the operation of the car, the reliability inherent in it during design and production is reduced due to wear of parts, corrosion, fatigue and aging of the material and other harmful processes occurring in the car.

The main task in choosing a repair strategy is to restore the vehicle to a level that ensures its use with the specified parameters during the next overhaul cycle with the lowest specific costs.

The functions of car repair production are the economically reasonable elimination of faults and the restoration of car life. Repair production has significant differences from mechanical engineering, which determines the need to study its specific processes, including the restoration of car properties,

lost during long-term operation.

Restoring damaged and worn-out parts is an important reserve for saving labor and material resources.

In recent years, the question of how to better repair cars has been increasingly raised. Repair by replacing the worn part with a new part or restore the old part.

Car parts, complex products that require strict compliance with technology in the manufacture. Therefore, the final price of the finished part is several thousand rubles. So is it worth throwing out such an expensive and complex product if its service life can be extended?

So, for example, in the production of automotive parts, the cost of materials and the production of blanks (castings, packages, stamping) is 70... 75% of their cost, and in the restoration of parts, these costs are 6... 8%, since the workpiece is the part itself and only those surfaces that have defects are processed .

The cost of restoring parts depending on their design features and the degree of wear is 10... 50% the cost of new parts.

The restoration of parts is a large reserve for providing automotive equipment with spare parts, the costs of which currently amount to 40... 60% the cost of overhaul of cars. Expanding the part recovery range reduces the need for spare parts.

Improving the reliability of repaired cars (units) depends on the quality of restoration of parts. Currently, the car repair industry has all modern methods of restoration, providing post-repair resources of parts at a level close to the resources of new ones.

In this regard, the purpose of this project is to develop engineering solutions for the organization and technology of repair of truck engines at the Bender Assembly Plant based on advanced methods of restoring and strengthening parts.

Analysis of production activities of the enterprise

1.1. History of the development of the Bender Automobile Assembly Plant

The enterprise was created in 1947 on the basis of a separate repair and restoration battalion of cars, which arrived from Hungary and created 133 KodVO (Red Banner Odessa Military District) on 6.0 hectares of the territory of the fortress in its northeastern part. The company specializes in overhaul of military vehicles modified by GAZAA, ZIS-5 and their units.

In 1961, 133 SARZ was disbanded and its fixed assets were transferred to the Bendery MTS (Mashinotractor Station), on the basis of which the BOERZ (Bendery Experimental Repair Plant) was formed, which was part of the Agricultural Machinery System of Moldova.

In 1962, 245 SARM was again created in the fortress to service KodVO automotive equipment, and on July 1, 1968, SARM was renamed ZRATT (Auto Tractor Equipment Repair Plant).

Production is 630 thousand rubles, personnel 180 people, territory 6.5 hectares. Overhauls of cars and their units of modifications GAZ51A, GAZ-63 were carried out, AG14 buses were manufactured on the basis of the GAZ51 chassis.

In 1974, ZRATT became 778 Auto Repair Plant subordinate to KodVO, and since 1979, as the overhaul of KamAZ cars was mastered, it was reassigned to the Glavtu MO SSR, and was operationally subordinate to KodVO.

Since 1976, the enterprise has been actively engaged in its reconstruction and technical re-equipment, first at the expense of its own funds (such as "housekeeping"), then with the attraction of funds

Ministry of Defense of the USSR. In parallel with the factory buildings, residential buildings were built, more than 300 families received apartments in new houses. The reconstruction was completed in 1987, and in connection with the development of new products - routine repair of military equipment (MAZ537543 tractors) since 1989 the plant has been renamed TSARZ (Central Auto Repair Plant) of the USSR Ministry of Defense, since 1991 Military Part 52110.

The design capacity of the Central Automobile Repair Plant (TSARZ) of the Ministry of Defense of the Soviet Union after the reconstruction and technical re-equipment of the 778M Automobile Repair Plant in 1989 amounted to 1,500 units of new products mastered - routine repair of military equipment for the overhaul of special road transport at the KamAZ Car Base and 500 units for the production of rocket locomotives .

The collapse of the Union led to the liquidation of enterprises of Union subordination and the withdrawal of units and formations from the territory of the Union Republics. Most of the property was transferred to local authorities.

In Pridnestrovie, all the remaining property was declared the property of the people of the PMR. In line with these processes, in 1993, BARZ (Bender Auto Repair Plant) was created on the basis of military unit 52110 and Nikolai Fedorovich Bogomolov was appointed director.

Since 1999, the assembly of GAZ cars from units and assemblies supplied by GAZ Nizhny Novgorod has been organized.

In April 1999, a center for maintenance and maintenance of cars was opened, where cars of all brands (including foreign cars) undergo an annual technical inspection using computer diagnostics.

In July 1999, from the GAZ3221 cars (minibus) assembled by the plant, a passenger convoy was formed by fixed-route taxis. Share taxis serve transportations on the lines TiraspolKishinev, Tiraspol-Slobodzeya, BenderyTiraspol, Tiraspol-Dnestrovsk, BenderyRybnitsa, Bender-Dubasari, Bender - Kamenka.

On May 21, 2001 SE (State Enterprise) of BARZ will be transformed to Joint Venture in the form of Closed joint stock company, 51% stocks of which are owned by the Hungarian firm "IntervestInvestments"" the director of DnestrAvto closed joint stock company Nikolay Konstantinovich Karaivanov is appointed.

The plant produces all types of repairs of KamAZ cars of all modifications, LAZ buses, KamA3740 engine. Since 1997, all modifications of GAZ vehicles (GAZ, Gazelle, Volga) have been repaired, pre-sold, warranty and maintenance.

In the 21st century, the plant entered as a multidisciplinary enterprise, which is confirmed by the list of products and services provided:

major (and all other types) repair and conversion of vehicles, all types and modifications;

assembly, additional equipment and pre-sales preparation of the automobile row of GAZ OJSC;

TO and TR of cars of all brands (including foreign cars);

automobile gasification - installation of gas balloon equipment for compressed natural gas;

passenger transportation by shuttle buses.

During 20022004, the company mastered the production of semi-trailers for KamAZ, MAZ vehicles with a carrying capacity of 2439 tons, and later - dump semi-trailers with a carrying capacity of 24 tons, trailers and semi-trailers for agriculture with unloading to both sides. In 2006, they began to develop 7 cubic meters of concrete mixers on the KamAZ chassis. Over the past three years, the main profile function of the KamAZ car overhaul enterprise has been restored, and GAZ3307, 3309, GAZ66 cars are being repaired.

Part of the production space and equipment is used together with tenants for the production of specialized and non-standard equipment (gas stations, grabs for logging, sawmills tape, forged products and equipment for the production of reinforced concrete products). With their participation, paints are selected and cars are painted with all types of modern paints, including powder, two- and three-component, cold galvanizing, etc.

Since March 2006, the plant has the status of a service center of KamAZ JSC. Komtrans magazine No. 4 for 2004 published an article entitled "Military Secret," in fact - a short historical excursion into the past of the enterprise.

In 2007, Dniester Auto CJSC became the winner of the Transnistrian Quality contest. In spring 2008, the company introduced a quality management system certified for compliance with the requirements of the International Standard ISO 9001. Also, passenger transportation carried out at the enterprise has been subordinate to the city of Tiraspol since 2008.

In 2012, by the decision of the Government of the PMR, the enterprise was reorganized into the open joint-stock company Bender Automobile Assembly Plant, and Batyr Nikolai Dmitrievich was appointed director.

The company organizes the manufacture of trailers and semi-trailers, including dump trucks with a lifting capacity of 30; 35; 45 m3 and special; foundry; development and implementation of new types of products, progressive technological processes; production of major, medium and current repairs of automotive and other equipment, as well as units for it; assembly, conversion of vehicles, maintenance and diagnostics, resale training of automotive equipment; production and sale of consumer goods.

1.3. Main types of economic activity, types of manufactured products

Bender Assembly Plant has production links with enterprises in various countries. Such as Ukraine and Russia (orders of steel-foundry products for the assembly of trailer frames and semi-trailers), Turkey (orders of running gear for trailers and semi-trailers), PMR (orders of steel-foundry products).

"Bender Automobile Assembly Plant" for the purpose of its business is a commercial organization, that is, pursuing profit-making as the main purpose of its business. The subject is production activities aimed at meeting the demand of domestic and external markets.

Main activities

production of billets obtained by casting method, products obtained by CNC plasma cutting.

Production of semi-trailers and trailers. Such as a Semi-trailer dump truck with a cargo volume of 30 m3., Semi-trailer dump truck 35 m3., Semi-trailer dump truck 45 m3., Semi-trailer - container ship "Dniester 9746", dump truck "Dniester 852310," multi-lift trailer Dniester 8323, onboard semi-trailer Dniester 9357, semi-trailer - grain truck "Dniester 93571," semi-trailer - grain truck "Dniester 935702," semi-trailer onboard extended Dniester 935703, semi-trailer onboard extended Dniester 935704, semi-trailer extended Dniester 935706, semi-trailer - dump truck "Dniester 9523V," semi-trailer dump truck with 2 bodies Dniester 952305, semi-trailer heavy truck PPT 9901, semi-trailer heavy truck extended PPT 990102.

production of major, medium and current repairs of automotive and other equipment, as well as units for it;

assembly, conversion of vehicles, maintenance and diagnostics, resale training of automotive equipment;

production and sale of consumer goods.

Production of specialized and non-standard equipment:

fuel distribution columns "Naina";

grips;

Horizontal UGL6500 Tape Machine.

Production of automotive kneaders with capacity of 7 m3 on KamAZ chassis

1.4. Technical and economic indicators of the enterprise

1.4.1. Production capacity of the enterprise.

In 1989, the design capacity of the Central Automobile Repair Plant (TSARZ) of the Ministry of Defense of the Soviet Union after reconstruction and technical re-equipment and the development of new equipment amounted to 1,500 units of routine repair of military equipment of special vehicles based on KamAZ cars and 500 units of missile locomotives .

Today, the capacity of the enterprise is about 150200 trailers and semi-trailers per year (depending on the types of trailers and semi-trailers); and about 5,000 tons of products made by casting.

1.4.2 . Annual output for the last three years.

At the moment, the production of the enterprise is minimal due to many problems:

legal problems in the PMR, in connection with which the plant was under arrest until January 2013;

Legal problems with the licence to sell trailers and semi-trailers, which prevents the sale of trailers and semi-trailers abroad;

No casting orders.

Today, billets are manufactured by casting for Russian enterprises.

1.4.3. Pay system in the enterprise.

Your company uses several wage types. As piecemeal remuneration (depending on the work performed), as well as a temporary and piecemeal-premium system of remuneration.

1.5. Analysis of organization of engine repair technology at the enterprise.

The program of work of the car repair enterprise for the repair of rolling stock is divided into works performed at posts and various production departments. These departments specialize in the types of work or units and systems of the car. Depending on the work program, they are sometimes called workshops, sites or departments.

Parts, instruments, assemblies and units removed from engines are repaired in production areas.

The main task of all these departments is to provide the repair areas with the necessary parts, units, instruments and units in a timely manner. The required number of workers in each department is determined by the actual labor intensity of the work performed. If it is impossible or impractical to perform repairs directly at the post, the part, device, unit or unit is removed from the car and, together with the control pass, sent for repair to the appropriate production department.

According to the results of pre-repair diagnostics, which can be carried out before it is sent for repair (before removal from the car), or at acceptance for repair (on the test bench), one of the pre-developed technological routes of the typical repair process is assigned. Engines directed along the same process route shall eliminate all defects provided by the route, regardless of the presence of a defect on a particular engine. This is accompanied by some increase in the scope of dismantling and assembly work due to incomplete correspondence, on the one hand, of actual combinations of engine defects directed along the corresponding technological route, and on the other, a combination of defects, the elimination of which is provided by this route. However, it will be compensated by a reduction in the volume of control and diagnostic operations, since in this case it is not necessary to localize all defects, but it is enough to establish the presence or absence of only those defects that determine the distribution of engines along technological routes. In addition, the organization of production is fundamentally changing, which is expressed in increasing its serial efficiency and accompanied by an increase in productivity and quality of repair.

In accordance with the process routes assigned to them, engines are distributed to specialized workplaces, with one or more process routes being carried out on one working one. When the engine is disassembled, its components are removed, removal of which is provided by the assigned process route. The removed components, replacement of which is not provided by the process route, are washed in the individual container and returned to the specialized workplace, and the components, replacement of which is provided by the process route, are sent to the washing in the common container, and then subjected to defects. Repair kits are supplied to workplaces (sets of parts necessary and sufficient to perform repairs along the assigned process route).

The results of repair diagnostics can confirm or refute the correctness of the assigned technological route. If defects of repaired engines are detected during inspection acceptance, they are either eliminated on site, or, if this is technically impossible or economically impractical, the engine is sent for re-repair.

Settlement and Organization Section

2.4.2 Composition of production and auxiliary areas

On the basis of the developed schedule of the production cycle, we choose the composition of production and auxiliary areas.

Disassembly and washing compartment

Punch and pick area

Repair department

Assembly compartment

Engine test and run-in compartment

Control Inspection Department

Painting and preservation area

Locksmith - mechanical section

Blacksmith - welding department

Galvanic compartment

In addition to the installed areas, we accept the auxiliary room:

Storeroom

Sanitary - household unit (washbasins, wardrobes, showers, toilets)

Administration

Waste Disposal Warehouse

2.4.3 Distribution of scope of work by production area

The scope of work is distributed as follows:

We take into account the level of qualification and the type of work performed in% of the total scope of work, and are guided by recommendations.

Distribution of labour intensity of works is carried out so that the level of load of production workers is within 95115%.

When allocating work, it is not allowed to combine the operation that is performed in violation of the technological sequence (that is, interruptions in the work of the production worker within 1 cycle are not allowed).

Process Section

Design and technological features of KamAZ engine cylinder block

In V-engines, the cylinder block is a massive cast body, from the outside and inside of which all mechanisms and systems are mounted.

The lower part of the unit is a crankcase, in the cast crossbars of which there are support seats for crankshaft bearings. Such a casting is often called a block crankcase.

In the middle part of the cylinder block there are holes for installation of sliding bearings for support journals of the camshaft. The block parting plane may extend along the axis of the crankshaft or be offset from its downward direction. A steel stamped tray serving as an oil tank is attached to the bottom of the crankcase. Oil from the tray is supplied through the channels in the unit to the friction parts of the engine. [12]

On V-shaped engines, to increase the stiffness of the cylinder block, its parting plane is located below the crankshaft axis.

In the cylinder block casting there is a jacket for liquid cooling of the engine, which is a cavity between the block walls and the outer surface of the insert sleeves. Cooling fluid is supplied to cooling jacket through two channels located on both sides of cylinder block. Distribution gear cover is attached to front part of cylinder block, and clutch case is attached to rear part.

The cylinder block belongs to the class of "body parts with thick walls."

They are manufactured by engines: [12]

● ZIL130 from gray cast iron No. 3, NV 170... 229 ;

● ZMZ53 from AL aluminum alloy 4 (a cover of radical bearings

- from the KCh 3510 malleable cast iron);

● YaMZ - from doped cast iron, NV 170... 241;

● KamAZ - from gray cast iron SCH 2144, LV 187... 241, and the covers of the main bearings - KH 3510, LV 121.. . 163.

The main bearing covers are not disassembled during repair with cylinder blocks, as are the clutch crankings.

Cracks on cylinder blocks (like holes) are their rejection features. However, it is allowed to eliminate holes by placing patches, and cracks - by brewing and sealing with synthetic materials with subsequent installation of reinforcing parts. [10,12]

3.2. Characteristics of cylinder block defects

During operation, the engine cylinder block is subjected to multiple temperature effects and receives large mechanical loads. The cylinder block can no doubt be called the basis of any engine. The unit head, units, gearbox are attached to it, and a piston group and a crank mechanism are located inside. Obviously, each of these units experiences loads, which means that large forces, variable in magnitude and direction, act on the cylinder block. And to resist them, the cylinder block must be sufficiently rigid, that is, not deformed by these forces. [10,12]

Main defects in the cylinder block: [10,12]

- holes on the walls of the cooling jacket or crankcase;

- wear of the ends of the first main bearing;

- cracks and breakaways;

- wear of the lower mounting hole for the sleeve;

- wear of the upper mounting hole for the sleeve;

- wear of holes for pushers;

- wear of holes in bushings for support journals of camshaft;

- wear and misalignment of sockets of core bearings inserts;

- wear of holes for camshaft bushings;

3.3. Analyzing Existing Cylinder Block Recovery Methods

As noted above, the following defects are found in most engine repairs other than engine cylinder wear: [10,12]

- deformation of bearing cover as a result of overheating

- turning of inserts with formation of deep breaks and catastrophic wear of holes

- destruction of bearing covers.

Repairing such holes with a bore does not allow for high performance, since it is quite difficult to provide a stable size and the necessary geometric parameters of the holes throughout the necks, there is a great danger of layering the hole, great difficulties in treating the welded hole or having an inclination after turning the inserts, high roughness of the treated surface worsens the heat sink, this is also facilitated by tape welding. Therefore, an inexpensive and efficient recovery method should be used to ensure minimal geometric errors, tight tolerance and the necessary roughness.

The restoration of cast iron body parts is fraught with difficulties due to the high tendency of cast iron to form solid structural components (ledeburite, martensite) and an increased tendency to crack formation. The latter is associated not only with the presence of ledeburite eutectic and martensite, but also with the low ductility and strength of cast iron. Therefore, work on restoring the mounting holes in the cast iron bodies of the parts is carried out in the direction of creating processes that would ensure the production of machined coatings by cutting. Such methods are :

1. Galvanic coating: (local ironwork, flowing ironwork, electronics, iron-zinc coating;

2. Application of epoxy compounds;

3. Flammable treatment;

4. Spraying;

5. Electric spark surfacing;

6. Gas powder surfacing;

The galvanic methods [14] have found some use in connection with the development of extravasal coating methods - the method of local iron plating and flow iron plating. The method of local baths is simple and is used in repair enterprises. A concentrated solution of iron chloride (600 g/l) with an acidity of pH = 0.60.7 at room temperature allows to obtain a sufficiently high-quality coating at a cathode current density Dk = 4... 8 A/dm2 with a thickness of 0.05... 0.15 mm. The disadvantage of the ironing method in local baths is the low rate of iron deposition - 0.10... 0.15 mm/hour, as well as the strict requirements for the stability of the ironing modes in all operations and the lack of the possibility of mechanization and automation of the process. Moreover, with this method, the electrolyte is quickly depleted and is not always enough to obtain the required quality and thickness of the coating.

The formation of sockets with epoxy compounds [14] has become somewhat common during the repair of cars, tractors and agricultural machines. In the USA, England, Japan, Finland, these materials are used to restore mating types "housing part socket - outer bearing ring." GOSNITI has developed a technology for restoring grooves for a rubber sealing ring in cylinder blocks with and without a repair ring. Repair of the above mentioned parts and conjugations consists in application of a layer of polymer material on the worn-out surface, its partial hardening and subsequent calibration to the nominal size. The disadvantages of the process are a significant proportion of manual work, the difficulty of mechanizing the process, as a result of which it is also time consuming to restore the part. Thus, partial curing lasts from 0.5 to 1.5 hours. After calibration, the reduced surface cures for 12... 24 hours at room temperature or 5 hours in a drying cabinet at temperature 60... 80 С. In addition, synthetic materials are subject to rapid aging and are inferior in many properties to metal coatings. Thus, the Brinell hardness does not exceed 11.0 MPa, the Martens heat capacity does not exceed 117 ° C, the average shear stress characterizing adhesion does not exceed 14.5 MPa. Method requires high accuracy of compliance with technology

The method of gas-flame treatment [14] for the purposes of restoration of landing surfaces is based on structural transformations in cast iron during its heating, which lead to the creation of residual stresses. Radial shrinkage of the hole when heated to 750... 850 ° C can reach 0.24 mm. However, under operating conditions, residual stress relaxation is observed, which leads to a change in geometric dimensions, so the radial shrinkage previously achieved during processing decreases. High heating of the part can cause its warping and disruption of the location of the mating surfaces and, as shown above, reduce the operability of the entire unit. For these reasons, the use of a flame-gas treatment method for restoring landing surfaces is ineffective .

GOSNITI proposed to restore the landing surfaces in the sockets for rolling bearings in cast-iron housing parts with gas-flame sputtering with composite material. [14] The worn hole shall be machined to eliminate distortions of the geometry (ovality, taper) and to adjust the dimensions to the required value, taking into account the allowance for the thickness of the layer to be sprayed. Surface degreasing is carried out by acetone or trichloroethylene by spraying with a pistol.

Electric spark surfacing [14] was developed at KAZNIPIAT and introduced in a number of enterprises. The essence of the method consists in the following. Electrode beam (80... 160 pcs.) with a diameter of 0.5... 0.8 mm report rotational motion at a speed of 600... 1250 rpm When a round bundle of electrodes rotates and contacts the part, electrical discharges appear and metal is applied to the surface. Build-up is performed by electrodes from Sv08 wire. A variation of this method is the restoration of the mounting surfaces by the rotating copper disk. To carry out the process of restoring the seat seats of the body parts, it is necessary to give rotation of the part at a speed of 30... 40 rpm. Electrode rotation speed - 600... 1250 rpm The part to be restored and the electrode rotate in opposite directions. Arc current is 200... 400A; voltage - 8... 12B. Longitudinal electrode feed shall be equal to 0.08... 0.1 mm/v. In two passes of the electrode, you can build up a layer with a thickness of 0.2... 0.3 mm per diameter. The built-up surface after calibration is a homogeneous metal without pores, shells and foreign inclusions. The disadvantage of the micro-surfacing method is that in forced electric modes, it is possible to obtain a surfaced layer up to 0.2... 0.3 mm per diameter. However, in this mode, the heating of the cast iron (the base of the part) becomes significant, bleeding and cracking of the sublayer appear, breakaways in individual areas are possible. With reduced current and voltage values, the heating of the part decreases, and then the thickness of the coating is 0.07... 0.08 mm per side. In both cases, the surface hardness of the deposited copper layer is lower than the hardness of the part material.

Gas powder surfacing [14] is a new low-temperature process of cast iron surfacing with powder alloys and is used for the purpose of correcting casting defects at finishing machining operations. Surfacing is carried out without spraying of the main metal. At the same time, the melting of the defect with thin layers (0.1... 3.0 mm) is possible due to the relatively small thermal deposition in the base metal, which does not cause significant deformations in the product. In the process of surfacing, pulsating powder supply is carried out, which ensures complete melting of grains of powder alloys. Studies have found that for the process of gas powder surfacing of cast iron, it is advisable to use powders with granulation of particles 40... 160 μm. The build-up density and cracks are monitored visually. Violation of process requirements may cause defects in the built-up metal. Based on the analysis of methods of restoring crankshaft beds in the cylinder block, it is more advisable to restore by applying polymer compositions.

3.6. Development of the recovery process

3.6.1 Development of sketch map and part roadmap

The sketch is not scaled. The required number of images, views, digits, sections, and detail views should provide clarity and clarity in the image of the surfaces to be restored. [10,12]

The sketch shows the part in the position the worker sees on the machine. Supports and clamps shall be designated in accordance with GOST requirements. [10,12]

The surface to be restored is surrounded by a solid thickened line. These surfaces are dimensioned with marginal deviations after the operation.

Dimensions are numbered in Arabic numerals. The dimension number is placed in a circle with a diameter of 6-8 mm and is connected to a dimension line. Numbering is carried out in the direction of clockwise movement.

We sketch for 30 operations: locksmith II. (refer to sheet 6 of graph. material)

This section discusses the most suitable process diagram of the unit recovery process, namely core bearing beds. Refer to the selected sequence of operation, equipment, accessory, tool with their execution modes in the form of roadmap in A1 format (refer to sheet 5 graph. material)

3.6.4 Compiling the operating map

The operating card is being developed for the main operation. The operating card includes all the information necessary for the worker to perform it: equipment and appliance data, the content of transitions.

Process transitions are numbered through within one operation. Auxiliary transitions are not numbered (for example, "install part as shown," "remove part," etc.)

The content of the transition is expressed in a mandatory form (for example: weld, drill, etc.) indicating its name and number of the size of the surface being treated.

Consider the contents of this process transition individually, as well as the design dimensions, fixtures, and tools used in restoring these parts.

Transition content: apply metal copolymer on the surface of supports beds dimensions 1 and 2.

Auxiliary tool: template shaft.

Cutting and measuring tool: blade, ham, metal polymer Chester Metal Super.

The developed map is shown on sheet 6 of format A-2.

3.6.5 Output

The developed technology of restoration of seats on bearings in the cylinder block will allow:

Reduce part repair costs

Increase surface wear resistance;

Extend the service life of the cylinder block after restoration;

Improve lubrication conditions for sliding bearings.

Design Section

4.1. Rationale for Design Development

In the previous section of this work, we have developed a process for restoring cylinder block beds using polymer compositions, namely using a metal polymer. The recovery technology provides for the application of a metal polymer layer (operating card) on a pre-boring and defatted surface. At the same time, the metal polymer, when applied, is initially in a semi-liquid state - this allows uniformly applying the polymer to the entire surface. To obtain an ideal internal surface, special "smooth" templates are used, made at the nominal size of the surface to be restored. The very process of restoring the seating holes in this way behind the cheapness of the materials hides the significant labor input of the process. This is especially the case for calibrating such fitting holes as cylinder block crankshaft supports. The difficulty of calibration lies in restoring not only the cylindrical and geometric shape, but also the axial distance. [12]

Currently, practically this method of restoration is used in the repair enterprises of Pridnestrovie, but without mechanizing the process of alignment and calibration of holes. All work is done manually. This reduces the performance of the engine repair process (especially in large repair plants) and reduces the accuracy of the recoverable surfaces. In this regard, in our opinion, it is more advisable to make a universal stand that allows you to repair the unit, including the restoration of individual surfaces and even simultaneous brewing of cracks with quick installation of the unit on the stand and accurate alignment of the restored holes.

When designing the bench, it is necessary to use unnecessary units and parts of the existing stands, lifts and accessories at the enterprise.

The stand shall be technologically non-metal-intensive, disassembled and assembled. [12]

Conclusion

The diploma project discussed the theme of designing a workshop for the repair of truck engines.

The company's analysis shows that a deep study of the main factors affecting the change in the technical condition of cars during operation, their reliability and durability, the introduction of progressive methods of car repair, the use of modern equipment allows to more fully ensure the quality of repair of trucks, reduce the cost of repair, increase the level of repair production, improve the use of equipment, reduce the time for repair of cars.

The main conclusions of the diploma project are:

1. The production program for repair of truck engines is justified;

2. Based on the production program, the scope of work, the number of workers, equipment were calculated and the engine repair workshop with updated equipment was designed.

3. The process of restoring the cylinder block with polymer materials has been developed.

4. A truck cylinder block repair bench has been designed, which has versatility for various brands of trucks, simplicity of design and high mobility, which reduces the time for repair of engines as a whole.

6. Health and environmental issues justified

7. A calculation of the technical and economic indicators of the engine repair workshop and the engine cylinder block repair stand was carried out, which will give a high result of designing the diploma project as a whole. The payback period of the workshop was 3 years, the payback period of the stand was 0.5 years.