There are three basic conditions for an electronically controlled engine to work properly

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.

Fast. 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.

Sensor. Sensors transmit information about engine 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.

Actuators. The various control functions to be completed by the 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.

The electronic control system works normally, the fuel supply system works normally, the gas distribution is timed, and the ignition system works normally.

The advantages of the engine electronic control technology are as follows:

1. Provide greater freedom of control; The electronically controlled fuel injection system can carry out optimal comprehensive control of fuel injection parameters (such as fuel injection volume, fuel injection timing, fuel injection pressure, fuel injection rate, etc.) according to different operating conditions. And the influence of various factors on the performance of diesel engine can be considered;

2. The control function is complete, the control accuracy is high, the dynamic response is fast, and the solenoid valve is used to control the amount of fuel injection, which can be very accurate;

3. The control accuracy of fuel injection timing is higher, which can improve the engine power, economy and emission performance;

4. Provide fault diagnosis function to improve reliability;

5. The transmission efficiency of continuous work is the highest under the economic speed, so as to achieve the purpose of fuel saving;

6. The smoothest gearbox type, power transmission breakpoint;

Disadvantages of engine electronic control technology

1. The life of the transmission belt is relatively short and the maintenance cost is high;

2. The power bearing is limited, and it cannot be applied to high-power engines, nor should it be over-modified or driven at high speed.

3. Because the transmission mechanism is not as rigidly connected as the gear combination, the slippage of the metal chain belt is the inferior root of its genes, which directly leads to the lack of its "transmission capacity".

1.Provides greater freedom of control.

The electronically controlled fuel injection system can carry out optimal comprehensive control of fuel injection parameters (such as fuel injection volume, fuel injection timing, fuel injection pressure, fuel injection rate, etc.) according to different operating conditions. And the impact of various factors on engine performance can be considered.

2.The control function is complete.

3.The control accuracy is high and the dynamic response is fast.

The solenoid valve is used to control the amount of fuel injection, which can be very accurate; The control accuracy of the injection timing is high.

4.It can improve the engine dynamics, economy and emission performance.

5.Fault diagnostics are available to improve reliability.

Computerized oil control, uniform, fuel saving.

The engine electronic control system mainly includes electronic fuel injection system, electronic ignition system and other auxiliary control systems. They have the following functions:

1. Fuel injection control --- electronically controlled fuel injection system (EFI) In the electronically controlled fuel injection system, the injection volume control is the most basic and important control content, the electronic control unit (ECU) mainly determines the basic fuel injection volume according to the air intake volume, and then corrects the fuel injection volume according to the signals of other sensors (such as coolant temperature sensor, throttle position sensor, etc.), so that the engine can obtain the best concentration of mixture under various operating conditions, so as to improve the power of the engine. Economy and emissions. In addition to injection volume control, the electronically controlled fuel injection system includes injection timing control, fuel cut-off control and fuel pump control.

2. Ignition control--- electronically controlled ignition system (ESA) The most basic function of the electronically controlled ignition system is ignition advance angle control. According to the relevant sensor signals, the system judges the operating conditions and operating conditions of the engine, selects the most ideal ignition advance angle, ignites the mixture, and improves the combustion process of the engine, so as to achieve the purpose of improving the engine power, economy and reducing emission pollution. In addition, the electronically controlled ignition system also has the functions of power-on time control and deflagration control.

3. Idle control --- idle control system Idle control (IS(:) system is an engine auxiliary control system, its function is to control the air intake of the engine through the idle control valve according to the engine coolant temperature, whether the air conditioning compressor is working, whether the transmission is in gear, etc., so that the engine can run at the best idle speed at any time.

4. Emission control --- emission control system Its function is mainly to implement electronic control of the work of the engine emission control device. The emission control items mainly include: exhaust gas recirculation (EGR) control, activated carbon tank solenoid valve control, oxygen sensor and air-fuel ratio closed-loop control, secondary air injection control, etc.

5. Air intake control --- air intake control system The function of the air intake control system is to control the air intake of the engine according to the change of engine speed and load, so as to improve the charging efficiency of the engine, so as to improve the engine dynamics.

6. Boost control --- boost control system The function of the boost control system is to control the work of the engine intake booster device. In a car equipped with an exhaust gas turbocharger, the ECU controls the increase based on the detected intake pipe pressure, thereby controlling the intensity of the booster on the intake gas.

7. Cruise control --- cruise control system After the driver sets the cruise control mode, the ECU automatically controls the engine according to the operating conditions and operating environment information of the car, so that the car automatically maintains a certain speed.

8. Warning prompts are controlled by ECU to control various indication and alarm devices, once the control system fails, the system can send signals in time.

9. Self-diagnosis function.

10. Fail-safe function.

11. Emergency function.

Hello, the control mode of electronically controlled engine: one is open-loop control, and the other is closed-loop control. 1. Open-loop control refers to the system control mode without feedback information.

When the operator starts the system and puts it into operation, the system will input the operator's instructions to the controlled object at one time. 2. Closed-loop control refers to a basic concept of cybernetics. It refers to a control relationship in which the output of the controlled returns to the input as the control in a certain way, and waits and exerts control influence on the input.

3. The difference between open-loop control and closed-loop control: whether there is anti-filial piety and only feeding; Whether it works on the current controller. Open-loop control is generally a control activity that is completed in an instant, and closed-loop control will last for a certain period of time, which can be judged.

The control mode of the engine electronic control system Fenghuai: open-loop and closed-loop; Open loop, no feedback after the actuator action; Closed-loop, after the actuator acts, the relevant sensors will feed the signal to the engine computer, and then correct the base resistance again, making the control more accurate.

On-off control and closed-loop control.

An actuator is an element of an electronically controlled BAI system. The electronic control system should complete various control functions of the blind, and it is realized by various actuators. In the process of control, the actuator converts the control bridge signal from the ECU into some kind of mechanical movement or electrical movement, so as to induce the change of the operating parameters of the engine and complete the control function.

1.The external circulation state is to use the fan to suck the air outside the car into the car, which also means that the air duct outside the car and inside the car is circulating, and the wind from the fan comes from outside the car. Sometimes I feel that there is still wind when the fan is turned off, just because of the owner's settings.

2.The internal circulation state is to close the airflow channel inside and outside the car, there is no airflow circulation without turning on the fan, and the airflow inhaled when the fan is turned on only comes from the inside of the car, forming the airflow circulation inside the vehicle. The inner circulation is mainly.

3.When there is a traffic jam, most of them use internal circulation, high.

The process of the engine electronic control system is mainly the main electronic control gasoline injection system, gasoline electric control ignition system, idle control system, exhaust purification and emission control, air intake and boost control, diesel electric control system introductionAt the same time, the structure and fault phenomena of some typical vehicle electronic control systems are briefly introduced, and the more commonly used vehicle network system is added.

1. Do not disassemble the sensor with electricity.

When the ignition switch is turned on, the 12V power sensor circuit on the engine cannot be removed to prevent the instantaneous voltage generated by the self-inductance of the coil in the sensor's internal device from damaging the ECU or sensor.

2. Diagnose faults according to the fault indicator.

When the EFI engine is faulty, first of all, observe whether the fault indicator light is lit, if it is lit, you can use diagnostic equipment to call up the fault**, and check the relevant components or electrical appliances according to the fault code prompt, if the indicator light is not lit, it should be checked according to the basic procedures.

(1) Consultation: Ask the user about the situation of the failure, the occurrence conditions, the fault phenomenon and whether it has been repaired.

2) Judge and check whether there is a mechanical fault, if it is a mechanical fault, proceed to step (3), otherwise go to step (5).

3) Repair mechanical failures.

4) Verify whether the fault phenomenon disappears after mechanical troubleshooting, and if it disappears, end the inspection. Otherwise, the electronically controlled gasoline injection system is faulty, continue to check.

5) Read the fault, and verify that the fault** exists, if it exists, go to step (7), if it does not, continue to check.

6) Use the fault symptom simulation method to verify the fault and repair the detected fault, go to step (9).

.Including electronic control of the powertrain. The electronic control of the chassis, the electronic control of the body system, the information communication system. Electronic engine control system, automatic transmission electronic control system, brake anti-lock braking system, airbag system, electronic suspension system, electronic power steering.

2.The electronic control system is the application of control devices to control and operate machinery and equipment or processes automatically and purposefully, so that they have a certain state and.

3.From the perspective of control principle, the automotive electronic control system can be simplified into three components: sensor, ECU and actuator. Sensors are perceptions.

4.The actuator is the actuator, and its function is to execute the special instructions of the ECU, so as to complete the control purpose.

1. Improve the uniformity of the mixed gas of each cylinder.

Electronically controlled multi-point injection is adopted, and the fuel is near the intake valve of each cylinder, so that the concentration of the mixed gas of each cylinder is basically the same, which is conducive to reducing the emission of CO and HC.

2. Improve engine power and economy.

The automotive electronically controlled gasoline injection system uses a microcomputer to control the precise amount of fuel injected, so that the power and economy of the engine are improved.

3. Reduce the amount of emission pollution.

The air-fuel ratio is controlled by oxygen sensor feedback to make it close to the ideal condition, so as to greatly reduce the emission of harmful substances such as CO, HC, NOX, etc., and the emission of harmful substances can be further reduced by exhaust gas recirculation, secondary air injection, and control of the optimal ignition advance angle.

4. Make the transition of engine working conditions more rounded.

When the operation of the automobile engine changes, the corresponding adjustment is quickly made according to the feedback signal of each sensor, and the amount of fuel injection and the timing of the fuel injection are quickly controlled, so as to provide the best air-fuel ratio suitable for the working conditions, and improve the response speed of the automobile engine to the acceleration and deceleration conditions and the smoothness of the working condition transition.

5. Improve the adaptability of the automobile engine to the geographical environment.

To improve the adaptability of the engine to geography and climate environment, the performance of the engine will change greatly, and the electronic control and gasoline injection system uses the volume flow method to measure the air intake, so as to correct the air-fuel ratio in time according to the atmospheric pressure and ambient temperature, so that the car can maintain good comprehensive performance in various geographical environments and climatic conditions.