1 Introduction
This article refers to the address: http://
1) Basic principles and construction of automobile engines
The working process of a car engine in the world today consists essentially of four strokes, namely intake, compression, expansion and exhaust. The expansion of the high-temperature and high-pressure gas generated by the combustion of the mixture of fuel and air in the cylinder, the engine performs work by externally outputting torque through the crankshaft by means of a crank-link mechanism. According to the fuel used, the engine can be divided into gasoline engine, diesel engine and gas engine; according to the ignition mode, it can be divided into ignition type and compression ignition type; the gasoline engine can be divided into theoretical equivalent combustion and lean combustion according to the ratio of air and fuel; according to the gasoline injection location, it can be divided into central injection, Inlet injection and in-cylinder injection.
The various parts of the engine can be divided into fuel supply system, intake and exhaust system, ignition system, crank connecting rod drive mechanism, lubrication system, cooling system and auxiliary system such as generator, starter, air conditioner compressor and various pumps according to their functions. Wait.
Engine operating conditions can be divided into cold start, after start, warm up, idle speed, partial load, full load, acceleration, deceleration and reverse tow. These conditions are primarily based on load and speed combined with engine temperature (ie, coolant temperature).
2) The importance of electronic control in the engine
Automotive electronic control begins with electronic control of the engine. Electronic Control was introduced to the engine in 1957 and commercialized in 1967. The original intention was to meet increasingly stringent emission regulations while improving the car's power, fuel economy and comfort. It is unthinkable that modern car and engine technology have left electronic control. The proportion of the output value of electronic products in the entire car increases with the increase of the car class, reaching more than 30%.
3) The core problem of engine electronic control
The core issues in the electronic control of gasoline engines are fuel metering and ignition timing. The core issues in diesel electronic control are fuel metering and fuel injection timing.
2. Composition of automotive and engine electronic control systems
Automotive and engine electronic control systems, like other electronic control systems, are also comprised of sensors, electronic control units (ECUs) and actuators.
1) Sensor
(1) The current sensors commonly used in gasoline engine electronic control systems are:
l Intake manifold absolute pressure sensor (provides absolute pressure information of intake manifold for calculation load, etc.)
l Fuel pressure sensor (providing fuel rail fuel pressure information)
l Fuel tank pressure sensor (providing fuel tank pressure information)
l Oil pressure sensor (providing oil pressure information)
l Coolant temperature sensor provided (providing engine temperature information)
l Intake air temperature sensor (providing intake air temperature information for calculating air density, etc.)
l Air conditioner evaporator temperature sensor (providing air conditioner evaporator temperature information)
l Air conditioning condenser temperature sensor (providing air conditioning condenser temperature information)
l Air flow sensor (providing air flow information for calculation load, etc.)
l Throttle position sensor (providing load information, load range information, acceleration and deceleration information)
l Accelerator pedal position sensor (providing load information, load range information, acceleration and deceleration information, etc.)
l Hall sensor (providing speed information, crankshaft position and phase information)
l Inductive speed sensor (providing speed information and crankshaft position information)
l Fuel tank level sensor (providing fuel tank level information)
l Knock sensor (provides vibration information received by the engine body)
l Exhaust gas recirculation valve stem displacement sensor (providing exhaust recirculation valve opening information)
l Oxygen sensor (provides information that the excess air ratio l is greater than 1 or less than 1)
(2) The current sensors commonly used in diesel engine electronic control systems are:
l boost pressure sensor (providing boost pressure information)
l Fuel pressure sensor (providing common rail fuel pressure information)
l Oil pressure sensor (providing oil pressure information)
l Coolant temperature sensor (providing engine temperature information)
l Fuel temperature sensor (providing fuel temperature information)
l Intake air temperature sensor (providing intake air temperature information)
l Exhaust temperature sensor (provides temperature information of exhaust port and exhaust pipe)
l Air conditioner evaporator temperature sensor (providing air conditioner evaporator temperature information)
l Air conditioning condenser temperature sensor (providing air conditioning condenser temperature information)
l Air flow sensor (providing air flow information)
l Throttle position sensor (providing throttle position information for exhaust gas recirculation control)
l Angle sensor (providing the distribution pump shaft angle information)
l Accelerator pedal position sensor (providing load information, load range information, acceleration and deceleration information)
l Hall sensor (providing speed and crankshaft phase information)
l Altitude sensor (provides altitude information)
l Vehicle speed sensor (providing speed information)
l Inductive speed sensor (providing speed information and crankshaft position information)
l Fuel tank level sensor (providing fuel tank level information)
l Exhaust gas recirculation valve stem displacement sensor (providing exhaust recirculation valve opening information)
l Oxygen sensor (providing the specific value of excess air coefficient l)
l Differential pressure sensor (providing differential pressure information of the particulate trap)
l NOX sensor (provides the NOX concentration information of the exhaust aftertreatment system)
2) Electronic control unit
The electronic control unit (ECU) accepts and processes various information provided by the sensor, and issues an instruction to the actuator according to the process to control the engine. The electronic control unit consists of a microcomputer and an analog circuit. With the continuous development of engine technology, the information processing capacity of electronic control units is getting larger and larger. Now the chips used have reached 32 bits, the number of transistors can exceed 7 million, the matching parameters can exceed 6000, and the number of pins can exceed 150. .
3) Actuator
(1) At present, the actuators commonly used in gasoline engine electronic control systems are:
l Electric fuel pump
l Electromagnetic injector
l ignition coil
l Various idle actuators
l Canister control valve
l Exhaust gas recirculation control valve
l Electric throttle (also known as electronic throttle)
l Hydraulic circuit solenoid valve (for variable valve timing control, etc.)
l Pneumatic circuit solenoid valve (for variable intake pipe length control, etc.)
l Fully variable valve electronic control actuator
l Turbocharged exhaust vent control valve
l Electric secondary air pump
l Three-way catalytic converter heating actuator
l cooling fan
l Air conditioning compressor electromagnetic clutch
l Other auxiliary equipment on the engine
(2) At present, the actuators commonly used in diesel engine electronic control systems are:
l Electric oil pump
l Various fuel injection pumps
l Fuel injection actuator (integrated in the fuel injection pump)
l Fuel injection advance angle actuator (integrated in fuel injection pump)
l Fuel shut-off valve (integrated in the fuel injection pump)
l Common rail high pressure pump
l Common rail pressure control valve
l Various common rail injectors
l High-pressure fuel solenoid valve for unit nozzle system and unit pump system
l glowing plug
l Exhaust gas recirculation control valve
l Electric throttle (also known as electronic throttle)
l Variable valve control actuator
l Variable intake pipe length actuator
l Turbocharged exhaust vent control valve
l cooling fan
l Air conditioning compressor electromagnetic clutch
l Other auxiliary equipment on the engine
Some diesel engine sensors and actuators are integrated into the fuel injection equipment, depending on the diesel injection equipment used.
3. Basic electronic control project for gasoline engine
1) Fuel quantity. This is the most important electronic control project for gasoline engines. The control object is the mass ratio of air to fuel entering the engine, which is determined by the ECU based on parameters such as engine load, speed, and coolant temperature. The load is the driver's torque requirement for the engine and is transmitted to the ECU by the amount of intake air or the position of the accelerator pedal. Actuators are electric fuel pumps and electromagnetic injectors. Fuel quantity affects the car's power, fuel economy, comfort, emissions and parts safety.
2) Ignition timing. The ignition timing is usually characterized by how many degrees of crank angle the piston is before the top dead center of the compression stroke, that is, the ignition advance angle, and is also determined according to the operating parameters such as the engine load, the rotational speed, and the coolant temperature. The actuator is an ignition coil. Ignition timing also affects the car's power, fuel economy, comfort, emissions and parts safety.
3) Knock control. Gasoline engine knock can damage the engine, worsening emissions and fuel economy. The main way to avoid knocking by electronic control is to reduce the ignition advance angle. Therefore, the knock control is implemented by the ignition timing control. However, too small an ignition advance angle will affect fuel economy. The purpose of knock control is to maintain the ignition advance angle at a critical point where knocking does not occur.
4) Fuel tank evaporative emission control. The evaporative emissions from the tank are all hydrocarbons and are hazardous. They must be adsorbed by activated carbon tanks and washed with fresh air when appropriate. The purge air stream is sent to the cylinder for combustion through the intake pipe. It is not possible to clean under any conditions, so the canister control valve is used to control the purge flow.
4. Basic electronic control project for diesel engines
The basic electronic control program for diesel engines is fuel metering and fuel injection timing. Both are controlled by the injection device based on information such as speed, load and coolant temperature. Here, the load information is provided by the accelerator pedal sensor. If the gasoline engine can be used or the accelerator pedal position sensor is not used, then the diesel engine must be used.
5. Extended Engine Electronic Control Project
1) Extended gasoline engine electronic control project
l Electronic control of variable intake pipe length. Used to improve engine power.
l Variable valve electronic control. Used to improve engine power, economy and comfort, and reduce harmful emissions.
l Pressurized pressure electronic control. Used to improve engine power and economy and reduce harmful emissions.
l Electronic control of exhaust gas recirculation. Used to reduce engine NOx emissions.
l Secondary air electronic control. It is used to meet the requirements of Euro 4 and above for hydrocarbon and carbon monoxide emissions.
l Three-way catalytic converter electronic heating or electric heating electronic control. It is used to meet the emission requirements of the Euro 4 or higher regulations.
l Parking-starting operation electronic control. It is used to improve engine economy and meet emission requirements of Euro 4 and above regulations.
l Cylinder closure and valve closing electronic control. Used to improve engine economy and reduce harmful emissions.
l Injection pressure and injection timing control. It is used for direct injection of gasoline to improve power and economy and reduce harmful substances.
2) Extended diesel engine electronic control project
l Electronic control of injection pressure. Used to improve engine power and economy and reduce harmful emissions.
l Electronic control of fuel injection. Used to improve engine power and economy, reduce harmful substances and noise emissions.
l Multiple injection electronic control. Used to improve engine power and economy, reduce harmful substances and noise emissions.
l Electronic control of variable intake pipe length. Used to improve engine power.
l Variable valve electronic control. Used to improve engine power, economy and comfort, and reduce harmful emissions.
l Pressurized pressure electronic control. Used to improve engine power and economy and reduce harmful emissions.
l Electronic control of exhaust gas recirculation. Used to reduce engine NOx emissions.
l Parking-starting operation electronic control. It is used to improve engine economy and meet emission requirements of Euro 4 and above regulations.
l Cylinder closure and valve closing electronic control. Used to improve engine economy and reduce harmful emissions.
l Microparticle trap regeneration electronic control. Used to reduce engine particulate emissions.
6. Outlook and conclusion
1) The engine electronic control system is a very promising market. With the gradual tightening of emission regulations and the gradual improvement of fuel economy requirements, engine technology is rapidly developing, and new electronic control technologies are still emerging.
2) Both say that the focus of the world's manufacturing industry is shifting to China. The automotive industry, including the automotive electronics industry, has also seen this trend to some extent. However, the original supporting products of China's engine electronic control system are basically from foreign-funded enterprises. Almost none of the components used in these companies' assembly products are produced in China. As a result, China has lost many of its GDP and jobs. State-owned and private enterprises have low technical standards and can only copy the products of foreign-funded enterprises, and follow the foreign-funded enterprises from the repair spare parts market. Some even sneak a sneak peek at the signs of foreign-funded enterprises, doing the work of producing counterfeit and shoddy products. This situation should be reversed. The government should see that the development of this industry will bring huge GDP growth and create a large number of employment opportunities. Therefore, the government should make plans to support and rectify this industry.
3) In order to revitalize China's own engine electronic control industry, it must first have a prerequisite: the automobile factory and the engine factory should cooperate with the engine electronic control parts manufacturers to share the risks and promise: once the domestic engine is proved The electronic control system can meet the requirements and use domestic products on the engines that it produces.
4) The vitality of the company lies in the development of new products. Engine electronic control technology is developed along with engine technology. China's car industry has consistently abandoned the independent development of engine technology, they have no way of knowing what the next generation of engines will be. The parts industry, including the engine electronic control industry, will not be able to develop its own new products, so it will always lag behind its foreign counterparts and always rely on imported technology. To change this situation, the engine factory must first abandon the consistent so-called "takenism", gradually transition from the introduction of technology to self-development, and absorb the system development and simultaneous development of component manufacturers involved in the product, so that they can jointly Innovation. There is no way to follow this. The government should guide and formulate incentive policies.
The typical Distribution Box is equipped with a solid case that is capable of protecting the interior components from various adverse conditions, such as excessive exposure to heat or cold. The wiring and other parts that are contained in the box are usually mounted within the interior, helping to lessen the potential for the components to be damaged during any type of shifting that would otherwise create some type of abrasive action on wire coverings and other elements.
We have a lot of Distribution Point Box,including 1pair drop wire box,4pair STB Module box,10pair Distribution Point Box,20pair DP box.What's more,we can provide you 10pair pouyet DP box.
The distribution box made of ABS, PC,have good quality and good price.
Distribution Box
Waterproof Distribution Box, Outdoor Distribution Box, Distribution Box
NINGBO YULIANG TELECOM MUNICATIONS EQUIPMENT CO.,LTD. , https://www.yltelecom.com