Design of the geely passenger car injector diagnostic and repair site

Introduction

In recent years, modern electronics technologies have been effectively introduced into the functional control systems of automotive engines. Spark-ignition gasoline engines will in the near future retain their dominant position as a power plant of a modern car.

During the operation of vehicles with electronic fuel injection systems, they need to be maintained. At the same time, electronic injection systems, which are high-tech equipment, require highly qualified maintenance and repair. The information and recommendations given in this work will allow the student in the future to competently organize the maintenance of ESUD fuel subsystems of passenger cars with a comprehensive diagnosis of electromagnetic injectors (EM) of fuel injection.

Diagnostics means the process of determining the causes of a malfunction by its signs. Note that for modern cars it is sometimes difficult to record the very fact of a malfunction.

On the one hand, the high reliability of modern automotive electronics has reduced the number of simple defects easily detected by maintenance station technicians. On the other hand, if a malfunction is observed, many probable causes can be specified for it. This complicates the problem of diagnosing modern cars. Diagnosis today is significantly different from what it was 1020 years ago.

Before electronic systems began to be widely used on cars, their electrical equipment consisted of several independent simple systems powered directly from the battery. Such circuits typically include a switch controlling the motor or other actuator, sometimes via a relay. Since there were few components, the technician easily determined malfunctions even on previously unknown car models. Simple elements were checked using a control lamp or multimeter (voltmeter, ammeter, ohmmeter in one case). More complex elements, such as relays, were checked by substituting a knowingly serviceable same element into the circuit.

This approach had its advantages, since inexpensive diagnostic equipment was required, the technician carried out diagnostics based only on his knowledge and experience.

Specialists of the car service were trained in order to fully understand the work and interaction of individual subsystems of the car's electrical equipment.

All cars of leading manufacturers since 1981 allow you to view engine mode parameters using a scanner connected to the diagnostic connector.

There are many parameters, and it is pointless to view them all in a row, the scanner will still not issue messages like "this value is wrong," although as the computer becomes cheaper and more complicated, the scanner software or ECU will be able to extract abnormal parameter values. It is necessary either to follow some algorithm, for example, available in the diagnostic map, or to see the most informative parameters of engine operation:

make sure that for the cold engine the temperature of the coolant and air in the inlet manifold coincide;

the valve of idling speed regulator must be opened by the permissible number of steps (or%);

the signal from the oxygen sensor must not descend below 200 mV, rise above 700 mV, the fronts are not gentle, the frequency is not less than 4 Hz.

Thus, we approached the history of the malfunction of nozzle contamination:

The main cause of pollution is the inevitable presence of heavy fractions in the gasoline composition. Solid resinous deposits appear on the nozzle seats and at the ends of the shutoff elements over time. They are the reason for the failure of the nozzles. Deposits are formed quite simply. After the hot engine stops, light fractions evaporate from the fuel film left on the pins and inner surfaces of the sprayers, which is below the shut-off valve. Heavy fractions remain on the parts, because there is nothing to wash them off at this time - fresh portions of fuel do not come to the sprayer, and the shutoff valves of the nozzles are closed. Resinous deposits are formed from these fractions. Accumulating, they prevent the locking cone from sitting tightly on the seat, as a result of which the tightness of the nozzle is violated. The residual fuel pressure in the ramp after stopping the motor remains for some time. It slowly pushes gasoline through a leaking valve, and the coking process is more intense. This causes a problem with the nozzles. One way to solve these problems is to clean the nozzles from deposits.

Relevance of the topic: consists in high-quality diagnostics of the injection system of modern cars. The use of modern methods of diagnosis and repair, as well as the high qualification of a specialist in car repair. Since, the fuel injection system does not allow deviations from the standards. The quality of this system on the car directly affects the durability of both the system itself and the engine as a whole, and this, in turn, leads to savings in operation both at short and long distances.

The main task is to ensure high-quality diagnosis and repair of the fuel injection system.

The purpose of the diploma project is: Design of the diagnostic and repair section of the injector of a car brand GEELY.

Conclusion

In the diploma project on the topic: Design of the diagnostic and repair section of the injector of a car brand GEELY. The purpose of which is to design a diagnostic and repair section for servicing the car injector.

In this work, the most important engine system of the car is considered as a fuel system, namely an injector. Since the injection system on modern engines achieves the best fuel efficiency of both the car as a whole and the enterprise if the car is found in service.

Modern diagnostic devices allow in the vast majority of cases to conduct diagnostics without removing the node. But, in the case of dismantling the unit, it is necessary to correctly and efficiently perform the order of action, which will make the injector "feel" and not damage it, since modern injectors are technological, the cost of error is high enough, thereby it will be extremely costly for the service enterprise.

In my diploma project, the following number of tasks were completed:

Analysis of technical literature on safety systems

The diagnostic post was calculated, in particular, the periodicity of TO-1 and

TO-2, calculated labor intensity for maintenance of TO-1 and TO2, calculated minimum number of work departments, payroll and cost of resources for performance of works

The technological equipment and equipment of the post are selected.

An analysis of safety measures was carried out, as well as the impact of the car on the environment.

Economic calculation completed

Based on the selected equipment, the technical and economic indicators were calculated, namely:

The first section of the project is devoted to the technical justification of the project: the standards of overhaul mileage, average values ​ ​ of overhaul mileage, labor intensity for conducting TO-1 are calculated - 2.2 people, TO-2 is 8.3 people/h, TR - 2.8 people/h. The idle time of the car during maintenance and maintenance is 20 days. The amount of maintenance for the year is calculated for all vehicles of the fleet TO1 = 3.5 and TO2 = 1.5. The annual mileage of all cars for the year was 9263155km. The second section defines the minimum number of workers in the department. The area of ​ ​ the compartment is 80.75 m2. The average monthly salary was 44175, rubles/person. One technician is required to perform this scope of work. Equipment was selected for the diagnostic and repair station and a detailed description was given. Measures on health, safety and fire safety during electrical work are also considered.

In the economic part of the diploma project, the costs of materials and components, the costs of equipping the workshop, the costs and the cost of repair work were calculated. The cost of repair work for 1000 km of mileage is 771 rubles.

Thus, I consider the goals and objectives of the diploma project fulfilled.