Development of the process of repairing TNVD and diesel engine nozzles

Contents

Introduction

1 Process section

1.1 Technical characteristics of the car

1.2 Purpose and operating conditions of the specified unit

1.3 Description of the structure, purpose and working conditions of the part to be repaired

1.4 Faults arising during operation of the specified unit, causes and methods of their elimination

1.5 Defect of parts included in the unit

1.6 Tools and accessories used during repair of the assigned unit

1.7 Process of repair of the assigned part

1.8Process of disassembly and assembly of the specified unit

1.9Define the time limit for disassembly and assembly of the specified unit

1.10Payment of annual labor intensity

1.11. calculation of the number of workers

1.12 Selection of process equipment of the section

1.13 Calculation of parcel area

1.14 Occupational and Environmental Protection Measures

Conclusion

Literature

Introduction

In this course project, I chose the KamAZ55111 truck. KamAZ55111 dump truck is a construction car with rear unloading. This car dump truck KamAZ 55111 is designed for transportation of various bulk construction and industrial cargoes.

The metal cabin, inclined, accommodating 3 people, is located above the engine, has noise and thermal insulation. The KamAZ55111 platform is all-metal with an inclined front side, welded, box type, protected by a visor that covers the space between the cabin and the platform, has a rear side, is heated by exhaust gases so that the cargo transported in the platform does not fit into it. The KamAZ55111 model has several types of configurations (5511101515, 55111-016-15, 5511101815, 55111-017-15). One of the advantages of the car is its relatively small dimensions, which allow you to move in cramped urban conditions. The undeniable advantages of this special equipment include the simplicity and reliability of the body design, the large angle of its rollover (60 °), a good view from the cockpit, stability, controllability, and the presence of an economical fuel system.

Creation History

In the CIS, the largest truck production enterprise is KamAZ OJSC. Geographically, it is located in the city of Naberezhnye Chelny, in the Republic of Tatarstan. This company is engaged in the production of large-capacity truck tractors, vans, dump trucks and special-purpose vehicles. The use of these machines is dictated by a long resource of use and high technical and operational parameters.

The Soviet automobile industry, throughout its existence, has never pampered consumers with a large choice of dump trucks produced. The 70s of the last century in the USSR were marked by economic growth and a construction boom. Many large construction projects were carried out in the country.

Under these conditions, the shortage of high-quality dump machines became increasingly noticeable, and to solve this problem, in 1976 the first stage of the legendary KamAZ was launched, which became one of the world's largest manufacturers of heavy trucks.

The first Kamazov dump trucks, which attracted the attention of their atypical bright yellow color for Soviet trucks, appeared on the construction sites of the city of Naberezhnye Chelny at the end of 1977. New dump trucks with an index of 5511 left the assembly line of the plant on October 11, 1977.

The KamAZ 55111 dump truck model is an improved modification of the 10ton model 5511. The improved model began to be produced in 199. The chassis was assembled directly at the KamAZ main site in Chelny, and in the city of Neftekamsk, a dump truck and an overturning body were installed on the chassis. The development of the 5511 dump truck was carried out by a team of KamAZ designers in collaboration with specialists from the Mytishchi machine-building plant. Since its introduction in 1988, this car has been considered one of the most popular construction machines in our country. Reliable, practical, convenient in operation - it combined all the characteristics so necessary for working equipment.

Course design is carried out in order to systematize, consolidate and expand the theoretical knowledge and practical skills acquired during the study of MDC 01.02 "Maintenance and repair of road transport," which is part of the professional module PM.01 "Maintenance and repair of vehicles" of the day form of training, and their application in solving specific problems of car service.

This course design was developed on the topic "Development of the technological process of repairing the TNVD and diesel engine nozzles."

Technical characteristics of the car

General Data

- manufacturer - KamAZ

- year of production - 1987-2012

- body type - Dump truck

- platform - Rear unloading, heating with exhaust pipes

- wheel mould - 6x4

Dimensions

- length - 6685 mm

- width - 2500 mm

Weight parameters and loads

-dressed weight a/m, kg - 9050

- load capacity a/m, kg - 13000

- total weight, kg - 22400

Engine

- model - KamAZ-740.51240 (Euro-2)

- type - Diesel with turbo supercharged

- power kW (hp) 176 (240)

- location and number of cylinders - V-shaped, 8

- working volume, l - 10.85

Gearbox

- type - Mechanical

- without divider - 5 stages of gears

- with divider - 10 stages of gears

Cabin

- type - Located above the engine, with high roof

- execution - Without sleeping space

Wheels and tires

- type of wheels - Disk

- type of tyres - Pneumatic, chamber

- tyre size - 10.00 R20 (280 R508) 11.00 R20 (300 R508 )

Dump truck platform

- platform volume, m cube - 6.6

- platform lifting angle, deg - 60

- unloading direction - Back

General characteristics

- maximum speed, not less than km/h - 90

is the angle of the preodole. lifting, at least,% - 25

- turning radius, outer overall, m - 9

- rudder hydraulic booster - Is

- tank volume, l - 250

- additional tank, l - Can be equipped, 350

- mileage without refuelling, km - 800

1.4 Faults arising during operation of the specified unit, causes and methods of their elimination

Malfunctions in fuel pumps and mechanisms units are expressed in the occurrence of foreign noises, visual inspection, fuel fuel leakage and severe overheating of parts.

1. One of the main causes of the TNVD failure is wear of the undercarriage. Dirt and coke are collected on the parts - this can also lead to malfunctions.

2. Most often there is such a problem as poor fuel supply, or its uneven distribution. Poor fuel supply may be due to:

- valve wear;

- deterioration of nozzle capacity;

- wear of plunger pairs;

- wear of rack teeth;

- damage of the toothed rim of the bushing;

- abrasion of plunger leashes, etc.

The change in the fuel injection angle is affected by the wear of pressure valves and plunger pairs, and the uneven fuel supply leads to unstable engine operation at low speeds and malfunctions in the operation of individual cylinders. The untimely moment of surge occurs as a result of the incorrect operation of a number of parts.

3.The high pressure pump housing is made of aluminium. Cracks and debris gripping bearings and various holes that are in hard-to-reach places are a sign of scrap. The remaining cracks and fractures can be eliminated by surfacing in argon.

Plunger pair parts are made of 25 X 5 MA steel. Jamming in the plunger sleeve is considered a marriage. If at an angle of 45 degrees, the plunger in various positions freely drops along the angle of rotation, there is no jamming. Loss of tightness results in wear of the working surface of the plunger pair. This breakage is eliminated by re-assembly (plunger and bushing are brought to roughness by lapping).

4. Defects of the piston include: wear of the edges of the slot, scratching and irregularities of the working surface, painting of metal on the edges of the slot, burrs and cracks. With a small oscillation of the crankshaft, the engine operates with failures. Smoke can occur from the drain pipe, bearings are heated .

5. Failure of bearing operation is determined by the following steps: the low-pressure pumping pump is removed, then a rigid rod of not large diameter is placed under the cam shaft and the operational state of the part is evaluated by pumping up - down.

6. Jamming of piston pairs is considered to be the main reason of improper operation of the LPT. Stopping the plunger conditionally of the bushing can cause jamming of the rack. In this case, the engine will not work. Most often, jamming of plunger pairs occurs due to water entering the gap.

On surfaces that are in a movable state, the lubricant is washed - this leads to heating and jamming of the surfaces. If water enters the fuel composition, corrosion of the sleeve and plunger appears. In case of plunger jamming, the roller, gear, key connections and regulator are broken. You can detect malfunctions in the plunger by disassembling it.

To do this, remove the pump cover and rotate the cam shaft several times. It is much more difficult to determine the incomplete hanging of plunger pairs. In case of improper operation of bearings fuel injection and supply to sections is disturbed. The advance angle does not coincide, the engine power decreases and exhaust smoke appears. When a uniform knock appears at idle, which intensifies under load, but weakens during heating, wear of pistons is observed. Defined visually.

In this case, it is necessary to completely analyze the engine and replace the necessary parts. In case of uniform knocking, it is necessary to remove the head and remove the foreign object, if any. There is such a problem due to foreign objects entering the cylinder. A uniform knock or screen sound in any mode indicates that the coolant pump, fan clutch or valve belt tension roller is not working properly. We need to find exactly the mechanism that fails and replace it.

7. High heating of the HPV engine with a fully serviceable cooling system design may be due to low supply of liquid for cooling. Such a failure can be determined visually, and it is eliminated when adding coolant. If there is a leak of oil through the gaskets, the presence of smoke and the instability of the engine at idle, it is necessary to disassemble the mechanism, change the gaskets, glands.

The oil emulsion in the cooling system appears when a crack occurs in the block or head passing through the oil channel. Urgent replacement or repair of damaged parts is required. It is impossible to solve the problem without disassembling the engine, it is necessary to completely or partially disassemble it into parts. An intermittent start-up knock indicates a low oil level. The problem is determined visually, and fixing it is very simple - in most cases you just need to add oil.

It is important to pay attention to any of these problems in time and eliminate them, because the effective operation of the TNVD directly depends on timely maintenance: oil replacement, high-quality fuel supply, equipment diagnostics, timely replacement of faulty and worn-out parts.

Malfunctions of nozzles. The operating injection pressure drops. The reason is that remote adjustment washers wear out or spring fatigue occurs. Indicate this type of malfunction the appearance of blue or black smoke and tougher engine operation. Solution - pressure adjustment on the bench.

The atomizer does not spray fuel. Nozzle sprayers are parts of the highest accuracy (belong to the fifth class of accuracy of manufacture), so they are immediately disabled by dirt or water. The working edge of the sprayer is damaged, and the quality of spraying drops, and the direction of injection changes. Signs of malfunction: blue smoke, reduced power, uneven engine operation (not all cylinders are in operation), strong knock. Some drivers think that if the nozzles are washed or cleaned, this will solve this problem. But it's not. It remains only to replace the sprayer.

The nozzle body has become leaking. This entails a leak. The edges of the nozzle body surfaces at the junction are deformed, most often due to repeated disassembly and assembly of the nozzle. In this case, the case must be changed. There may be a leak from under the puck (on Japanese cars). This happens if the landing planes of the reverse washers are damaged. Washers themselves are to be replaced, straightening of the reverse frame and nozzle housing on the lathe is necessary.

1.5 Defect of parts included in the unit

Fuel equipment shall be repaired only in special workshops. When disassembling and assembling, remember that the plunger pairs of the LPG piston and low pressure pump housing sections, the low pressure pump rod and bushing, the piston and cylinder of the manual fuel supply pump are exactly selected pairs and are not subject to disassembly.

Main defects of LPT parts and methods of elimination:

- housing of high pressure fuel pump is made of aluminium alloy AL9, fragments and cracks, gripping holes for nozzles and bearings and located in hard-to-reach places, are rejection features; all other cracks and debris are eliminated by surfacing or welding in argon medium; wear of the hole for plunger pushers is eliminated by treatment for repair size, at the size of this hole the housing is scraped, wear of the hole for bearings of the load holder is eliminated by galvanic grating or setting of the DRP, wear of the hole for the axis of the intermediate gear, for the axis of the rack lever and for the axis of the spring lever is eliminated by setting of the DRP with further deployment to the dimensions of the working drawing;

- a defect such as the jamming of the plunger in the sleeve is a rejection feature; no jamming if the plunger is freely lowered in different positions along the angle of rotation in the sleeve when the pair is installed at an angle of 45 degrees; wear of plunger pair working surfaces, as well as traces of corrosion on the end surface of the bushing, which leads to loss of tightness, are eliminated by re-assembly; for this purpose plunger and its bushing are lapped and brought to roughness 0.1 mcm with permissible ovality 0.2 mcm and taper 0.4 mcm; then the plungers are divided into dimension groups and selected according to the respective sleeves; further, the plunger and sleeve are lapped, washed in gasoline and no longer impersonated;

- defects of plunger bushing include chipping and dyeing of metal at holes, bolts, scratches, wear of working surface, increase of diameter of inlet and cutoff windows, cracks and weakening in places of fit. Wear of working surface of plunger bushing shall be measured with accuracy up to 0.001 mm, ovality, cone-shaped and enlargement of bushing hole - by micrometric or indicator instrument for measurement of internal surfaces with fission price up to 0.001 mm and cone gauges;

- defects of the plunger include metal painting on the edges of the screw slot, wear of the edges of the slot, scratching and scratching on the working surface, wear of the working surface and cracks. To detect distortion of plunger geometry with a minimum with accuracy up to 0.001 mm when its arrow is set to zero according to the initial sample or caliber in the form of a cone bushing;

- check the value of clearance in plunger pair on pressure bench with falling load. Before testing, wash the steam parts thoroughly in filtered diesel fuel. Install the plunger pair in the bench seat, the plunger - in the maximum supply position. Fill the above-plunger space with filtered diesel fuel. Install sealing plate on the bushing end, clamp it with screw, then release the load latch. Under its action, fuel gradually begins to extrude through the gap in the pair, and the larger the gap, the faster. The plunger load value must correspond to the fuel pressure value 195-205 kgf/cm2. Complete lifting of the plunger up to the moment of cut-off under the influence of load, accompanied by fuel squeezing through the gaps between the bushing and the plunger, should occur not less than 20 s. If the time of plunger lifting up to cut-off exceeds 40 s, then install the plunger pair wetted with filtered diesel fuel to the vertical position on the end of the bushing, before laying a sheet of clean paper. After a five-minute hold when raising the pair behind the plunger shank, the bushing must be lowered from the plunger under the influence of its own weight;

plunger pusher is installed in pump housing hole with nominal clearance of 0.025-0.077 mm. The maximum permissible clearance during operation is 0.20 mm. Measure outer diameter of plunger pusher with micrometer or brace measuring 30.91;

- in the unit of pusher roller - roller bushing - roller axis the main defect is wear of mating surfaces. Nominal total clearance 0.029-0.095 mm, maximum permissible 0.30 mm. If wear exceeds the specified limit, disassemble and repair the pusher; Note here that measurements are made separately.

The maximum allowable clearance in the connection is the roller axis - roller bushing at wear of surfaces - 0.12 mm, in the connection the roller bushing - pusher roller - 0.18 mm. Measure external surfaces of parts with micrometer, internal surfaces with nutrometer with indicator.

When re-assembling the pusher, keep the value of the initial tension in the connection of the pusher roller axis - the plunger pusher along the hole into which the roller axis is pressed.

Provide value of initial tension by selection of roller axis along hole in pusher housing from different sets. The maximum permissible outer diameter of the pusher roller is 19.90 mm with a nominal diameter of 19.955-20.000 mm;

- main defects of the pressure valve: hairlines, balls, traces of wear and corrosion on the cone surfaces, on the guide surface and on the end of the seat, on the discharge belt of the valve are eliminated by lapping on the plate with lapping pastes; Note here that valve seat is secured in collet holder by threaded surface; The end surface roughness of the seat shall be Ra 0.16 μm and the guide hole and sealing cone Ra 0.08 μm; after selection and lapping, the valve pair is not impersonated; absence of valve jamming in the seat is determined by its free movement under the influence of own weight in different positions along the angle of rotation after the valve extends from the seat by 1/3 of the length;

- cracks, dents, corrosion traces are not allowed on the pressure valve surface. Wear of the valve is manifested in loss of tightness along the sealing cone and in jamming of the valve in the seat. Use a tenfold magnifying glass to detect defects. If tightness is lost, wipe the seat and valve together by cone with paste with grain size not more than 3 mcm. When the valve is stuck in the seat of the part, wash with diesel fuel. If the jamming is not eliminated, replace the pair;

Main defects of parts of RPM regulator and methods of their elimination:

- replace the upper and rear covers of the regulator in case of cracks on them. If the strainer is clogged, blow the strainer with compressed air in the rear cover of the regulator. If the filter is defective, replace it. The operating oil flow through the filter must be at least 1.6 l/h at a pressure of 1-3 kgf/cm2;

- to determine suitability for further operation, the holder of regulator loads assembled with cargoes must be inspected and measured without disassembly, since during pressing out the parts can be damaged and the mating of cargoes, which are selected with static moment difference of not more than 2 kg/cm2. Perform partial or complete disassembly of the unit only at wear exceeding the permissible one, or at destruction of parts.

Clearance between regulator spring lever and lever axis pressed into pump housing must not exceed 0.3 mm. Increase of regulator spring length is permitted during operation up to 59.5 mm at nominal length 57-58 mm.

Main defects of parts of low pressure pump and manual fuel supply pump and methods of their elimination:

- replace low pressure pump and manual pump in case of cracks on the housing, fractures, mechanical damages, corrosion leading to loss of mobility of mating parts;

- pay special attention to the state of the rod-bushing assembly of the low pressure pump, since the amount of wear in the coupling depends on the amount of fuel flowing into the cavity of the cam shaft. The clearance in the specified coupling must not exceed 0.012 m. Check the clearance value without removing the bushings from the pump housing by determining the time of air pressure drop from 5 to 4 kgf/cm2 in the accumulator with a volume of 30 cm3.

Nozzle defect. The main defects of the nozzles are poor spraying of the fuel, its leakage through the shutoff part of the sprayer and mismatch of the injection pressure. These defects occur due to wear of nozzle parts and loss of spring elasticity.

Worn-out working surfaces of housing and locking needle of sprayer are restored with lap. Repaired nozzles are checked for quality and fuel spray angle, tightness and injection pressure. A device is used for this purpose. It consists of cast-iron housing, into which plunger steam and engine pressure valve are inserted.

Device plunger is actuated by lever to feed fuel to nozzle secured on cylinder by flywheel. Fuel pressure is measured by pressure gauge. Diesel fuel is supplied to plunger steam via tube from tank. A silencer is installed to collect fuel coming out of the nozzle. Tightness of nozzle is determined by time of pressure drop. Pressure from 200 to 170 kgf/cm2 must fall within 9-20 sec. At that, the adjustment screw of the nozzle must be tightened by injection pressure of 250 kgf/cm2. Further, the nozzles are adjusted for the working pressure of the spray by unscrewing the adjusting screw of the nozzle. At the same time cone angle and spray quality are checked. Angle of spray cone is determined by diameter of fuel imprint on paper.

1.6 Tools and accessories used during repair of the assigned unit

Disassembly and assembly of diesel engine units shall be performed using benches, process platforms, jacks, tilters, racks, extractors, guide bushings, special wrenches and other devices ensuring mechanization of heavy and labor-intensive operations provided for by repair rules, job instructions or instructions.

All these mechanization tools are divided into 3 groups: technological equipment, with the help of which various operations are carried out to repair diesel locomotives and their elements; The organizational tooling necessary for the organization of this production and the technological tooling necessary for the execution of the operations of this production.

Process equipment includes machines, benches, installations, both stationary and mobile, lifting mechanisms, washing machines, lubricating, control and diagnostic units, wrenches, etc. Organizational equipment includes workpieces, racks, supports, cabinets, lari, necessary for the organization of work in production areas and in areas of repair and maintenance production. Process equipment includes: tools, instruments, accessories, necessary for direct execution of operations. At TP3 and depot CG TNVD is removed and disassembled.

1.8 Process of disassembly and assembly of the assigned unit

To remove TPLP, disconnect the cables of the manual control of the engine shutdown lever and the regulator control lever, the fuel supply control rod, the fuel supply pipes to the pump, the discharge and drain pipes and the pipe from the fuel fine filter, the pipe for oil supply to the pump, the oil outlet pipe;

- remove the tie bolt of the front flange of the driving half-coupling, two bolts of the driven half-coupling (to turn the bolts to a convenient position, turn the crankshaft by the holes on the flywheel through the hatch of the clutch case);

- disconnect the pipelines that supply fuel to flare plugs, high-pressure pipelines (remove them), air supply pipe to pneumatic cylinder of auxiliary brake;

- remove four bolts of fuel pump attachment;

- remove the pump.

Disassembly of TNVD must be performed in the following order:

- remove screws for attachment of rear cover of rotation speed regulator and remove cover assembled with low pressure pump;

- to remove the automatic coupling of advancing of injection of fuel, using I801.16.000 adaptation. First remove nut (2) (Fig. 11, a) of coupling attachment. To do this, insert screwdriver (4) into the nut slot and hold clutch (1) from rotation by wrench (3). Then remove the coupling by screwing the extractor (5) into the coupling (see Fig. 11, b);

- disassemble and remove screws for attachment of protective casings of TNVD sections and remove the casings;

- break and remove the bolts that attach the upper cover of the regulator and remove the cover;

- remove the axis of regulator lever and remove regulator lever with load coupling lever, clutch, regulator spring and spring lever;

- remove the locking ring and holder of goods assembled;

- remove the racks plugs, remove the racks bushings, then the racks themselves, before that unlock them;

- remove the nuts of TNVD sections attachment, remove the lock washers of the sections connectors and remove the TNVD sections and plunger pushers;

- to rasshplintovat and turn off nuts and, using the I801.26.000 stripper, to remove the clown of the drive of the pump of low pressure, the leading gear wheel of the regulator and an intermediate gear wheel;

- remove the second bearing from the intermediate gear axis;

- knock out the keys from the nose and shank of the cam shaft, remove the cover of the rear bearing, remove the cam shaft assembled with the bearings and remove the cover of the front bearing;

- using the I801.30.000 stripper, to remove bearings from a camshaft;

- to sort sections TNVD and the toplivopodkachivayushchy pump of low pressure in I801.20.000 adaptation. For a vypressovka of the delivery valve of section TNVD to use I801.21.000 adaptation.

Assembly of LPT must be performed in reverse order. For installation of bearings on a camshaft to use I801.27.000 adaptation. By selecting the adjusting gaskets under the cover of the front bearing of the cam shaft, it is necessary to provide a free shaft stroke of not more than 0.1 mm.

Disassembly and assembly of nozzle.

1. Wash the nozzle thoroughly and blow with compressed air.

2.Install the nozzle in the disassembly and assembly accessory.

3. Remove the plug of nozzle housing.

4. Remove the nut of the sprayer. Press the sprayer with stop.

5. Remove the sprayer housing, preventing the sprayer needle from discharging.

6. Remove the nozzle needle from the housing and remove the nozzle housing from the accessory.

7. Remove spacer assembly.

8. Remove the rod, spring, adjusting washers from the nozzle housing. Remove the nozzle connector and remove the bushing and filter from the connector housing and remove the sealing ring from the housing. If the filter is defective, replace the filter.

10. Replace the filter, install the sealing ring on the nozzle housing, install the bushing and tighten the nozzle connector.

11. Install adjusting washers, spring and rod in the nozzle housing.

12. Provide spacer assembly.

13. Install the nozzle housing on the accessory and install the sprayer needle, and install the sprayer housing.

14. Tighten the nut of the sprayer by stop the sprayer.

15. Remove the plug of nozzle housing.

16. Remove the nozzle from the accessory for assembly and disassembly of the sprayer.

14. Tighten the nut of the sprayer by stop the sprayer.

15. Remove the plug of nozzle housing.

16. Remove the nozzle from the accessory for assembly and disassembly.

Conclusion

This course design was developed on the topic "Development of the technological process of repairing the TNVD and diesel engine nozzles in the conditions of Aznakaevskoye UTT LLC"

The technological section indicates: the technological characteristic of the car, which includes: the year of release of the car, engine volume, maximum speed, fuel tank volume, acceleration time, start and end of release, and other technical characteristics.

The purpose and design show the advantage and disadvantages in the same way as the operation of a given unit.

Malfunctions occurring during operation.

The principle of variable gearbox operation is described.

The main malfunctions arising at operation of TNVD and nozzle of KmAZ55111 are presented in the section of troubleshooting.

Tools and accessories used during repair of TNVD and KamAZ55111 nozzle.

The process of repair is presented.

The technical process of restoring parts of the "plunger pair" type includes: washing, defect surfacing, grinding, locksmithing, washing, control.

Process of disassembly and assembly of TNVD and KamAZ55111 nozzles.

You have defined a time rate for each operation.

The annual work capacity is calculated to be 4370 people * h.

Calculation of the number of workers is equal to m = 2 people.

The area of ​ ​ the plot is protected, which is equal to 48.9 m2

Labor Protection provides: general rules for equipment maintenance, general requirements for occupational safety, PPE, etc.