What is the difference between the electronically controlled fuel system of a diesel engine and the

Among the two major institutions and the five main components of the system of electronically controlled diesel engine and traditional diesel engine, the fuel system is quite different. The traditional diesel engine uses a mechanical oil pump to pressurize the diesel fuel and then inject it into the cylinder through the injector, and the injection pressure and injection time cannot be controlled with the different working conditions of the engine; For the electronically controlled diesel engine, a set of electronic control system has been added, mainly including ECU, common rail pipe, high-pressure oil pump, etc., the common rail pipe is mainly used to store high-pressure diesel, play a role in stabilizing pressure, and ensure that the injection pressure of the engine is relatively stable under different working conditions; By calibrating the rail pressure, advance angle and other parameters, it ensures that the engine has sufficient power and the lowest fuel consumption under different working conditions.

However, due to the additional set of control system, the cost of electronically controlled diesel engine will be higher, and there are relatively many failures of precision parts.

The electronically controlled fuel system of the diesel engine includes the electronically controlled high-pressure common rail system (CRS), the electronically controlled unit pump (EUP), the electronically controlled pump nozzle (EUI), and the electronically controlled in-line pump (EIL) plus electronically controlled cooling EGR system. At present, there are many electronically controlled high-pressure common rail systems and electronically controlled in-line pumps (EIL) plus electronically controlled cooling EGR systems in China III, and the country IV stage is basically the world of electronically controlled high-pressure common rail systems.

In fact, EFI refers to the electronically controlled injection system, which is basically the same as the electronically controlled fuel system, but everyone says it differently.

1) Accurate measurement, uniform spot spray, random correction, so that the air-fuel ratio is always kept in the best area.

2) "Three nos" bring "three good".

3) Obtain the "three harvests" of power, economy and purification. Engine power increased by 15 20 ; The fuel consumption rate was reduced by 1 5 ; Significant reduction in emission pollution values, CO L, HC 100 10 6.

4) Improved cold start performance, hot start performance, transition performance, rapid deceleration and anti-pollution performance, load self-adjustment performance, and non-extinguishing performance.

5) The control function has been expanded, and the self-diagnosis function has been added.

6) Reduce the failure rate of gasoline engine oil circuit and circuit.

Electronically controlled gasoline engines have these advantages as follows:

Sewn the shirt age galloping evenly.

The power and economy of the engine are improved.

Reduced open pollution.

The condition is overly sleek.

The adaptability of the gasoline engine to the geographical and climatic environment is improved.

It improves the high and low temperature starting performance and warm-up performance of the gasoline engine.

Electronically controlled engine working principle.

The engine speed and load are used as the basic signals reflecting the actual working conditions of the engine, and the basic fuel injection volume and injection timing are determined by referring to the fuel injection volume and fuel injection timing spectrum corresponding to each working condition of the engine obtained from the test.

Then according to various factors (such as water temperature, oil temperature, atmospheric pressure, etc.) to compensate for it, so as to obtain the best fuel injection volume and fuel injection timing or ignition timing, and then control the output through the actuator.

1. Reduce emissions and pollution.

The gasoline direct injection system can quickly and accurately provide the best air-fuel ratio according to the different working conditions of the engine, so that the gasoline can be completely combusted, and at the same time, the three-way catalytic system can effectively reduce the emission of CO, HC and NOx harmful gases. In particular, when the engine decelerates sharply, it has the function of cutting off oil. When decelerating sharply, the throttle closes, but the engine is running at high speed, the amount of air entering the cylinder decreases, and the vacuum in the intake manifold increases.

In the carburetor type oil supply system, the amount of fuel injected into the main nozzle increases at this time, and at the same time, the gasoline adhered to the inner wall of the intake manifold evaporates sharply and enters the cylinder, so that the mixture becomes thicker, resulting in incomplete combustion and an increase in harmful gases in the exhaust. When the electronically controlled gasoline engine decelerates sharply, the engine speed is higher than a certain value, and the fuel supply will be automatically interrupted, which can completely eliminate the harmful gases that cannot be removed by the traditional carburetor when decelerating, and reduce the pollutants in its exhaust emissions.

2. Increase the maximum power of the engine.

Because the intake air of the electronically controlled gasoline engine does not need to be preheated, the intake and exhaust pipes can be arranged on both sides of the engine respectively, such as for the structure to race closer, the exhaust pipes are arranged on both sides of the engine block, and good heat insulation is required between the two, so that the air density of the inhaled cylinder is larger. The air intake of the electronically controlled gasoline engine is not limited by the carburetor throat, coupled with the large diameter of the matching, the transition is very smooth The intake pipe can greatly reduce the intake resistance, improve the intake efficiency, and thus improve the maximum power of the engine, and the fuel consumption is low, and the economic performance is good.

The electronically controlled gasoline engine can achieve the engine under various working conditions, accurately control the air-fuel ratio as the optimal value, and the gasoline is sprayed out under a certain pressure. The atomization quality is good. At the same time, the intake pipe is not limited by gasoline atomization, and can be designed more reasonably, so that the mixture is evenly distributed like a cylinder, so the fuel consumption is low.

Compared with the mechanical injection of the carburetor, the atomization of the oil is higher, the time is more accurate, the lean combustion technology is facilitated, the combustion efficiency is improved, the power control is more accurate, and it is less easy to block.

Fuel injection is more accurate EFI engines use electronic control devices instead of traditional mechanical systems (such as carburetors) to control the fuel supply process of the engine. For example, the gasoline electromechanical injection system is to input the engine temperature, air-fuel ratio, throttle condition, engine speed, load, crankshaft position, vehicle driving status and other signals into the electronic control device through various sensors, and the electronic control device calculates and controls the amount of fuel injection required by each cylinder of the engine and the injection time according to these signal parameters, and sprays the gasoline into the intake pipe through the injector under a certain pressure for atomization. It is mixed with the incoming air stream and enters the combustion chamber for combustion, thus ensuring that the engine and catalytic converter are always working optimally.

This type of engine, which is controlled by an electronic system and injects fuel from the injector into the engine's intake system, is called an EFI engine.

The biggest difference between an electronically controlled engine and a carburetor engine is the fuel supply system. The fuel supply system of the electronically controlled engine has eliminated the carburetor, but a number of electronic automatic control devices have been added. These include many sensors, actuators, and ECUs.

Electronically controlled engines have to do not only what carburetors do, but also what carburetors can't do. For example, the specific concentration of air-fuel in a combustible mixture can be controlled within the required range. The oil circuit and circuit of the carburetor engine are very clearly divided and do not affect each other much.

The electronically controlled engine fuel supply system increases the electronic control part, which makes the oil circuit and circuit interconnected, which not only affects the work of the engine fuel system, but also affects the normal operation of the engine. Due to the increase in electronic control devices for electronically controlled engines, this makes the entire structure of the engine, including the electronic control system, more complex.

Quick navigation. Structural composition.

How it works. Parameters to be measured.

Merit basic idea.

In the initial stage, the function of the system is realized by replacing the mechanical control technology with electronic technology, and its function is expanded, so that the performance is greatly improved; After the development to a certain extent, electronic technology can promote the essential change of the system principle, so that the limitations can be broken through, so that the engine performance can be greatly improved.

Electronically controlled engine.

Structural composition. Electronic control unit.

The electronic control unit (ECU) is the heart of the engine's electronic control system. It completes the collection of various parameters of the engine, the control of fuel injection volume and fuel injection timing, and determines the function of the entire electronic control system.

The sensor sensor transmits the information of the engine operating conditions and environment to the ECU in real time and realistically through various signals.

In other words, what the ECU learns is just an engine made up of many signals. Therefore, the accuracy, reproducibility and immediacy of sensor information directly determine the quality of control.

The various control functions to be completed by the actuator electronic control system are realized by various actuators.

In the control process, the actuator converts the control signal from the ECU into a certain mechanical motion or electrical movement, thereby causing the change of engine operating parameters and completing the control function.

How it works. The engine speed and load are used as the basic signals reflecting the actual working conditions of the engine, and the basic fuel injection amount and fuel injection timing are determined with reference to the fuel injection amount and fuel injection timing spectrum corresponding to each working condition of the engine obtained by the test, and then various compensation is made according to various factors (such as water temperature, oil temperature, atmospheric pressure, etc.), so as to obtain the best fuel injection amount and fuel injection timing or ignition timing, and then control the output through the actuator.

Summary. No, there is no way to use ordinary diesel in the EFI engine Nowadays, when the driver suddenly releases the accelerator pedal (so that the throttle is completely closed), the engine does not need to output torque, but is dragged by the kinetic energy of the car. This case is referred to as a drag or coasting case.

In order to reduce waste emissions and reduce fuel consumption and improve driving characteristics in the dragging condition, the electronic control system ** controller recognizes that the engine is in the dragging condition, first immediately postpones the ignition angle at that time, and then cuts off the fuel injection to the engine, so that the transition process of the working condition is relatively smooth. When the engine speed exceeds the specified speed limit **speed limit 2) and the throttle valve is closed, the nozzle will no longer inject fuel, and the oil supply of the engine will be cut off; Once the engine speed is lower than the next speed limit **speed limit 3), the nozzle will start to inject fuel again. If there is a sharp drop in engine speed during dragging, such as during emergency braking, the nozzle will resume fuel injection at the higher speed **speed limit 1) to prevent the engine from falling below idle speed or the engine from stalling completely.

No, there is no way to use ordinary diesel in the EFI engine Nowadays, when the driver suddenly releases the accelerator pedal (so that the throttle is completely closed), the engine does not need to output torque, but is dragged by the kinetic energy of the car. This is known as a drag or slide. In order to reduce waste emissions and reduce fuel consumption and improve driving characteristics in the dragging condition, the electronic control system ** controller recognizes that the engine is in the dragging condition, first immediately postpones the ignition angle at that time, and then cuts off the fuel injection to the engine, so that the transition process of the working condition is relatively smooth.

When the engine speed exceeds the specified speed limit **speed limit 2) and the throttle valve is closed, the nozzle will no longer inject fuel, and the oil supply of the engine will be cut off; Once the speed of the engine is lower than the next speed limit **speed limit 3), the nozzle will re-ridge and start to spray oil. If there is a sharp drop in engine speed during dragging, such as during emergency braking, the nozzle will resume fuel injection at the higher speed **speed limit 1) to prevent the engine from falling below idle speed or the engine from stalling completely.

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EFI diesel engine refers to a diesel engine that uses electronic control of fuel injection and emissions, that is, an EFI diesel engine.

At present, there are three mainstream technical routes for the electronic control mode of diesel engine to achieve three emissions, namely electronically controlled single pump, electronically controlled pump nozzle and high-pressure common rail.

At present, the major international auto parts manufacturers are developing diesel common rail injection systems, such as: Bosch, Delphi, Siemens, Denso, VDO and Magna Marelli, which are the world's main common rail injection system manufacturers, and Bosch is currently the only one that produces common rail diesel injection systems in China.