What are the functions of the idle control system? What are the different types?

The main contents of idle speed control are: post-start control, warm-up process control, load change control, deceleration control, etc.

The idle control system is a subsystem of the electronically controlled engine, which is mainly composed of sensors, ECUs and actuators.

Idle speed control adopts the closed-loop control mode of engine speed feedback method, that is, the engine speed sensor compares the actual speed of the engine with the target speed, determines the control amount of the engine to reach the target value according to the difference of comparison, and corrects the engine idle speed through the actuator.

Vehicle speed sensor signals and throttle position sensor signals are used to determine whether the engine is idling. When the throttle is in the idle position and the vehicle speed is less than 2 km h, the ECU confirms that the engine is in idle condition and activates the idle control system to implement idle control.

Signals such as coolant temperature sensor signals, air conditioning compressor connection signals, automatic transmission gear signals, and battery voltage are used to determine the target speed when the engine is idling. The target speed values under different idle conditions are pre-stored in the ECU's memory. The engine speed signal is used as a feedback signal for the idle control system, which is used to calculate the amount of control.

The ECU is generally not set separately, but is shared by the fuel injection system, ignition system, etc., which simplifies the system and improves the control accuracy. The role of the actuator is to adjust the air intake of the engine and achieve idle speed control. According to the different ways of adjusting the air intake, it can generally be divided into two types:

One is the bypass air type that changes the cross-sectional area of the bypass air channel, and the other is the throttle direct action type that directly changes the throttle opening.

The composition of the engine idle control system is shown in the figure, which is composed of various sensors, signal control switches, electronic control unit ECUs, idle control valves, and throttle bypass air ducts. The ECU receives the signals from the relevant sensors, analyzes and discerns them, and sends corresponding instructions to the Idle Control Valve (ISCV) to control the air flow in the throttle bypass, so that the engine is always at the optimal speed when idling.

There are three types of idle control systems:

1: The adjustment of the idle screw of the carburetor, just adjust it directly.

2: EFI is the computer to determine the number of revolutions of the engine according to the signals of each sensor of the engine.

3: There is also a kind of electrified damper carburetor type, which controls the idle speed according to the time, generally 1-2 minutes to reach the normal value.

Purpose of Idle Control:

1. Reduce idle emissions;

2. Improve fuel economy;

3. Improve the stability of idle speed;

4. Get good driving comfort;

5. Achieve rapid and smooth transition characteristics.

In addition to stabilizing the basic idle speed, it is also possible to simplify the air intake system by consolidating some functions that were previously possible with various additional devices.

Gasoline engine idle control system is an important part of contemporary EFI gasoline engine control. The control performance of the idle condition reflects the technical indexes of the vehicle, such as technology, stability, power, economy, and pollution.

When the engine is idling, it is called idling, which means that the car is in neutral gear. The idling speed of a car is not a speed, but a working condition. Idling is the engine "not working".

When the engine is idling, it is called idling. When the engine is running, if the accelerator pedal is completely relaxed, the engine is idling. The rotational speed at which the engine is idling is known as the idle speed.

The idle speed can be adjusted by adjusting the damper size, etc. Generally speaking, the lowest idle speed is the lowest speed when the engine is not shaking.

Engine idling function: Idle speed is a device to overcome the running resistance of the engine itself and maintain the minimum speed of the engine, so as to facilitate the driver to drive and stop temporarily under various circumstances. If you're waiting for a traffic light, or in a traffic jam, this time is usually short, and you can't just turn off the engine and restart it just to wait for that time.

The take-away control system can be adjusted to the after-sales one, although it is a movie that can be adjusted, if you do it at that time, you can adjust it to a low place, and if it is an odd number, you can adjust it to a high place.

It can reduce idle emissions and improve fuel economy, improve idle stability, obtain good driving comfort, and achieve fast and smooth transition characteristics.

Three forms: 1 duty cycle, 2 rotary spool valves, 3 stepper motors.

It consists of a throttle position sensor, an actuator and a control unit.

The engine idle control system is mainly composed of the engine ECU, actuators, various sensors, etc.

The technical term should be called idle control valve.

The idle control valve is installed on the air hole of the throttle bypass, and the idle control valve is activated to increase the engine speed when the engine speed is lower than 750rpm according to the ignition signal, and it will stop when the engine speed exceeds 1050rpm. In vehicles equipped with air conditioning systems, this control valve is also called the idle speed increase valve, and after the air conditioning compressor acts, the engine load is generated, so that the engine idle speed is reduced, and the idle control valve acts accordingly to maintain the stability of the idle speed.

The idle control valve is powered by the ignition switch, as long as the ignition switch is turned to the ON position, the idle control valve is energized, and the engine computer controls its circuit. When the engine's operating parameters deviate from the normal value, the valve is used to adjust the idle speed. The idle speed is adjusted by controlling the amount of air in the bypass throttle body.

After the engine starts, the idle control valve is opened for a period of time to increase the air intake, which increases the engine idle speed by about 150r-300r. When the engine coolant temperature is low, the idle control valve opens to get the right amount of fast idle. The engine computer controls the position of the idle control valve plunger by changing the signal strength transmitted to the idle control valve according to different coolant temperatures.

The stepper motor idle control valve is one of the most widely used idle control devices in the world. It is used to bypass the opening of the air passage of the automotive EFI system, so as to adjust the bypass air volume so that the engine speed reaches the required target value. Structural principle:

It consists of a rotor made of a permanent magnet, a stator made of an excitation coil, and a feed screw and valve that converts rotary motion into linear motion. It uses the stepping signal supplied by the system to carry out conversion control, so that the rotor can rotate forward or backward, so that the valve core (screw rod) can carry out telescopic movement to achieve the purpose of adjusting the bypass air duct cross-section, so as to stabilize the idle speed and achieve the ideal idle speed.

The idle system is composed of three parts: engine, cylinder block and piston.

When the engine is in the idle condition, the idle control system continuously monitors the engine speed and compares it with the target speed in the current engine state, when the engine idle speed fluctuates and deviates from the set target speed, the ECU outputs a control pulse to make the idle control actuator act, and adjusts the engine's idle speed within the set target speed range.

Precautions for overhaul of automotive electronic control system.

It is strictly forbidden to disconnect the battery from the circuit when the engine is running at high speed, so as to prevent transient overvoltage from damaging the microcomputer and sensors.

When the engine fails, the "check the engine" warning light is lit, the battery can not be disconnected from the circuit to prevent the fault code and related data information stored in the computer from being cleared. Only after the fault code and relevant information are called up through the self-diagnosis system and the cause of the fault is diagnosed, the battery can be disconnected from the circuit.

Composition of idle speed control system: 1) sensors: speed sensor, throttle position sensor, water temperature sensor, start switch signal, air conditioning switch signal, vehicle speed sensor, neutral start switch signal, hydraulic screenwriter load signal, power steering switch signal, engine load signal.

2) Actuator: Idle Control Valve 3) ECU

Answer: Hello, I am happy to serve you Dear, the idle control system of the engine is composed of various 2113 sensors, signal control switches, electronic control units ECU, idle control valves 5261 and throttle bypass air ducts. The ECU receives the signal from the 4102 from each related sensor, and after analyzing and distinguishing, the 1653 sends corresponding instructions to the idle control valve (ISCV), and then controls the air flow in the throttle side plate, so that the engine is always at the best speed when idling.

It consists of a throttle position sensor, an actuator and a control unit.

1. Start control: when the engine starts, the idle speed control system controls the idle actuator to maximize the bypass air intake to facilitate starting; After start-up, the amount of bypass air intake is determined according to the cooling water temperature.

2. Warm-up control: In the warm-up stage, the idle control system continuously adjusts the size of the bypass air intake according to the change of cooling water temperature, so that the engine can maintain a stable speed under the condition of temperature state change.

3. Idle feedback control: When the warm-up process is over, or the ECU detects the throttle full closing signal, and the vehicle speed is less than 2km h, the idle control system starts to carry out idle feedback control.

4. Idle speed control when the electrical load increases: When the number of electrical appliances used at the same time increases, the idle control system should also increase the bypass air intake volume accordingly to increase the idle speed of the engine.

The idle speed control system includes stable idle speed control, fast warm-up control, high idle speed control, and other controls.

When the engine is idling, the throttle is in the fully closed position, i.e. the amount of air entering the engine is no longer regulated by the throttle. The essence of idle control is to adjust the air intake through the idle actuator, and at the same time cooperate with the control of the fuel injection volume and ignition advance angle to change the power emitted by the fuel consumption under idle working conditions to stabilize or change the idle speed.

When the engine is started, the electronic idle control system automatically opens the idle auxiliary air channel to the maximum to make the engine start easy; Control valve in activated carbon canister. When working such as the exhaust gas recirculation control valve, adjust the idle control valve to stabilize the idle speed.

Answer: The composition of the idle speed control system: 1) Sensor:

RPM Sensor, Throttle Position Sensor, Water Temperature Sensor, Start Switch Signal, Air Conditioner Switch Signal, Vehicle Speed Sensor, Neutral Start Switch Signal, Hydraulic Screenwriter Load Signal, Power Steering Switch Signal, Engine Load Signal. 2) Actuator: Idle Control Valve 3) ECU

Idle speed control principle: ECU compares the target speed determined from the input signal of each sensor with the actual engine speed, and determines the control amount equivalent to the target speed according to the difference obtained from the comparison, and drives the actuator of the air volume to keep the idle speed near the target speed.

2.Types of idle control actuators: throttle direct-acting and bypass air.

Answer: Closed-loop control In order to accurately control the actual air-fuel ratio around :1, in the engine control system, the air-fuel ratio feedback control mode composed of oxygen sensors is generally adopted, that is, the closed-loop control mode.

For this purpose, an oxygen sensor is installed in the exhaust manifold or exhaust pipe in front of the three-way catalytic converter to measure the oxygen content in the exhaust gas and feedback the corresponding voltage signal to the ECU. The ECU controls the increase or decrease of fuel injection based on the air-fuel ratio concentration signal fed back by the oxygen sensor.

Exhaust gas recirculation control The main components in the exhaust gas are CO2, H2O and N2, which have a high heat capacity. When the new mixture is mixed with the partial exhaust gas, the heat capacity also increases. When combustion is carried out with the same amount of calorific energy, the combustion temperature decreases compared to that without mixing, and the formation of NOx is suppressed.

Secondary Air Intake Uses fluctuations in exhaust gases to open and close the leaf spring valve, allowing air to enter the exhaust manifold intermittently.

Secondary air injection uses an air pump that forces air into the exhaust manifold.

Activated carbon tank gasoline evaporation pollution control When the engine is working, the ECU controls the opening and closing of the solenoid valve of the carbon tank to control the vacuum degree of the upper part of the emission control valve according to the engine speed, temperature, air flow and other signals, so as to control the opening of the emission control valve. When the emission control valve is opened, gasoline vapor is sucked into the intake manifold through the emission control valve.

Answer: Timing control By extending the opening time of the intake and exhaust valves, the inlet and outlet capacity of the gas is increased, so as to improve the working state of the intake and exhaust valves, and then improve the performance of the engine. (I don't know if it's correct).

Cylinder breakage control When the engine is running under partial load, the control system commands to cut off the gasoline supply and ignition of several cylinders, stop the work of several cylinders, and the working efficiency of the remaining cylinders is increased, thereby improving the efficiency of the engine and reducing fuel consumption. When the power can not meet the requirements, the rest of the cylinder will be resumed.

Basically, there are 3 types.

1: The adjustment of the idle screw of the carburetor, just adjust it directly.

2: EFI is the computer according to the signal of each sensor of the engine to determine the number of revolutions of the engine 3: there is also an electric damper carburetor type, according to the time to control the idle speed, generally 1-2 minutes idle speed to reach the normal value.