Calculation requirements of traditional engine control
Publish: 2021-04-27 05:21:29
1.
1. Different properties: the fuel supply system of electronic control engine cancels carburetor, but adds many electronic automatic control devices. It includes many sensors, actuators and ECUs. Engine is a kind of machine that can convert other forms of energy into mechanical energy, including internal combustion engine (reciprocating plug engine), external combustion engine (Stirling engine, steam engine, etc.), jet engine, motor, etc
Different characteristics: compared with traditional ignition, electronic ignition has higher ignition energy, precise ignition time control, higher reliability and stronger rability. The electronic control ignition system can ensure the best ignition advance angle under any working condition, so that the mixture entering the cylinder can be fully burned, which not only saves fuel, but also increases power, and reces exhaust pollution3. The principle is different: the electronically controlled engine not only has to complete the task of the carburetor, but also has to complete the task that the carburetor is difficult to complete. Engine displacement is the sum of the working volume of each cylinder of the engine, generally expressed in liters (L). The working volume of cylinder refers to the volume of gas swept by piston from top dead center to bottom dead center
extended data:
precautions:
1. The fuel must be clean: there are many impurities in the fuel, which will accelerate the wear of the electric fuel pump and rece the service life of the fuel pump. In addition, the unclean fuel will lead to the blockage of the fuel filter and injector, affect the fuel supply pressure and normal injection volume, and rece the performance of the engine
Supplement fuel in time: the electric fuel pump of EFI engine should meet the requirements of sufficient fuel and stable working pressure of injection system. Most of the fuel pumps are installed in the oil tank and immersed in the oil to cool the pump motor, rece noise and prevent air resistance. When the fuel in the fuel tank is insufficient (some warning lights flash), the fuel should be replenished in time to prevent the fuel pump from being burned Proper selection of fuel: the engine has higher requirements on the quality and brand of fuel, while the EFI engine has higher requirements. For vehicles with catalytic converters and oxygen sensors, only unleaded high-grade gasoline can be used. If leaded gasoline is used, the catalytic converter of exhaust gas will fail and the oxygen sensor will also fail when driving more than 400 km, which will affect the normal operation of the engine2. Electronically controlled fuel injection system (electronically controlled gasoline injection system, high pressure common rail electronically controlled diesel injection system), oxygen sensor, three-way catalytic converter, feedback control system, variable intake device (variable valve timing, variable valve lift, variable intake manifold length, closed cylinder fuel saving, etc.), exhaust gas recirculation device, forced crankcase ventilation device, gas evaporation control device, etc
automobile engine is the engine that provides power for automobile and the heart of automobile, which affects the power performance, economy and environmental protection of automobile. According to different power sources, automobile engine can be divided into diesel engine, gasoline engine, electric vehicle motor and hybrid power
common gasoline engines and diesel engines are reciprocating piston internal combustion engines, which convert chemical energy of fuel into mechanical energy of piston motion and output power to the outside. Gasoline engine has high speed, low quality, low noise, easy starting and low manufacturing cost; Diesel engine has higher compression ratio, higher thermal efficiency, better economic performance and emission performance than gasoline engine
in addition to gasoline and diesel, other new energy vehicles are called new energy vehicles, including pure electric vehicles, hybrid electric vehicles, fuel cell vehicles, gas vehicles, bioethanol / biodiesel vehicles and hydrogen vehicles. Most of the new energy vehicles on sale in China are hybrid electric vehicles, but at present, pure electric vehicles have been taken as the main direction
control system is a management system with its own goals and functions, which is composed of control subject, control object and control media
control system means that it can keep and change any interesting or changeable quantity in the machine, mechanism or other equipment in the desired way. At the same time, the control system is implemented to make the controlled object reach the predetermined ideal state. The control system makes the controlled object tend to a desired stable state
for example, suppose there is a driving system of a car, and the speed of the car is a function of its accelerator position. The desired speed can be maintained (or the desired speed change can be achieved) by controlling the pressure of the accelerator pedal. The driving system of the car (accelerator, carburetor and engine vehicle) forms a control system.
automobile engine is the engine that provides power for automobile and the heart of automobile, which affects the power performance, economy and environmental protection of automobile. According to different power sources, automobile engine can be divided into diesel engine, gasoline engine, electric vehicle motor and hybrid power
common gasoline engines and diesel engines are reciprocating piston internal combustion engines, which convert chemical energy of fuel into mechanical energy of piston motion and output power to the outside. Gasoline engine has high speed, low quality, low noise, easy starting and low manufacturing cost; Diesel engine has higher compression ratio, higher thermal efficiency, better economic performance and emission performance than gasoline engine
in addition to gasoline and diesel, other new energy vehicles are called new energy vehicles, including pure electric vehicles, hybrid electric vehicles, fuel cell vehicles, gas vehicles, bioethanol / biodiesel vehicles and hydrogen vehicles. Most of the new energy vehicles on sale in China are hybrid electric vehicles, but at present, pure electric vehicles have been taken as the main direction
control system is a management system with its own goals and functions, which is composed of control subject, control object and control media
control system means that it can keep and change any interesting or changeable quantity in the machine, mechanism or other equipment in the desired way. At the same time, the control system is implemented to make the controlled object reach the predetermined ideal state. The control system makes the controlled object tend to a desired stable state
for example, suppose there is a driving system of a car, and the speed of the car is a function of its accelerator position. The desired speed can be maintained (or the desired speed change can be achieved) by controlling the pressure of the accelerator pedal. The driving system of the car (accelerator, carburetor and engine vehicle) forms a control system.
3. The control strategy of electronically controlled diesel engine mainly refers to the injection technology of diesel engine. Now the mainstream technologies are: electronically controlled pump nozzle technology and high pressure common rail technology
high pressure common rail EFI technology is a kind of fuel supply mode that separates the generation of injection pressure and injection process completely in the closed-loop system composed of high-pressure oil pump, pressure sensor and electronic control unit (ECU). The high-pressure fuel is delivered by the high-pressure oil pump to the common fuel supply pipe (rail), and the oil pressure in the common fuel supply pipe is precisely controlled, so that the pressure of the high-pressure oil pipe has nothing to do with the engine speed, which can greatly rece the change degree of the fuel supply pressure of the diesel engine with the engine speed.
common rail technology refers to the high-pressure oil pump, the high-pressure oil pipe, the high-pressure oil pipe and the high-pressure oil pipe In the closed-loop system composed of pressure sensor and ECU, the generation of injection pressure and injection process are completely separated from each other. The high-pressure fuel is delivered to the common fuel supply pipe by the high-pressure oil pump, and the oil pressure in the common fuel supply pipe is precisely controlled, so that the pressure of the high-pressure fuel pipe has nothing to do with the engine speed, It can greatly rece the change of fuel supply pressure with engine speed, so it can rece the defects of traditional diesel engine. ECU controls the fuel injection quantity of the injector, which depends on the pressure of the fuel rail (common fuel supply pipe) and the opening time of the solenoid valve
1 high pressure common rail technology
the common rail system separates fuel pressure generation and fuel injection. If the unit pump diesel injection technology is compared to the revolution of diesel technology, the common rail can be called a rebellion, because it deviates from the traditional diesel system and is similar to the sequential gasoline injection system. Common rail system opens up a new way to rece diesel engine emissions and noise
Europe can be said to be a paradise for diesel vehicles, with diesel cars accounting for 39% in Germany. Diesel car has a history of nearly 70 years, and in the last 10 years, diesel engine has developed rapidly. In 1997, Bosch and Benz jointly developed the common rail diesel injection system. Today, in Europe, many brands of cars are equipped with common rail diesel engines, such as Peugeot's HDI common rail diesel engine, Fiat's JTD engine, and Delphi's multec DCR diesel common rail system
the common rail diesel injection system is different from the previous diesel injection system driven by camshaft. The common rail diesel injection system completely separates the generation of injection pressure and injection process from each other. The traditional mechanical injector is replaced by the injector controlled by solenoid valve. The fuel pressure in the fuel rail is generated by a radial piston high-pressure pump. The pressure is independent of the engine speed and can be set freely within a certain range. The fuel pressure in the common rail is controlled by an electromagnetic pressure regulating valve, which continuously adjusts the pressure according to the working requirements of the engine. The pulse signal of ECU acting on the solenoid valve of injector controls the injection process of fuel. The amount of fuel injection depends on the oil pressure in the fuel rail, the opening time of the solenoid valve and the liquid flow characteristics of the nozzle
fuel injection pressure is an important index of diesel engine, because it is related to engine power, fuel consumption, emissions and so on. The common rail diesel injection system has increased the fuel injection pressure to 1800 bar
in the last two years, cars with direct injection diesel engine have been developed significantly in Europe, with high efficiency and excellent fuel economy, and reced engine noise. The direct injection diesel engine uses a pump nozzle system, which is used by the domestic 1.9tdi bora. The maximum injection pressure can reach 1800 bar. Although the pump nozzle direct injection system is good, the fuel pressure can not be kept constant. With the more stringent emission control, higher and constant diesel injection pressure and more perfect electronic control are needed. Therefore, many manufacturers regard the diesel common rail system with more advantages as the development direction of diesel engine. This system has high fuel pressure and can provide flexible fuel distribution control. It can flexibly control fuel distribution, fuel injection time, injection pressure and injection rate through ECU. Through the control of the above characteristics, the common rail has made the diesel engine's responsiveness and driving comfort reach the level of gasoline engine, at the same time, it has significant fuel economy and low emission characteristics
high fuel pressure can be ensured in all engine speed ranges, and high injection pressure can obtain good combustion characteristics at low engine speed.
for the engine with axial piston type distributing pump driven and controlled by camshaft, the fuel system pressure is linearly related to engine speed, which leads to insufficient fuel pressure at low engine speed, The common rail system can achieve very high fuel pressure in all engine speed ranges. Flexible electronic control system for timing and injection pressure control can achieve low emissions and high efficiency under various engine conditions. Because the formation of pressure is separated from the injection process, the engine designers have more freedom to study the combustion and injection process. The injection pressure and injection timing can be adjusted according to the requirements of the engine working conditions, so that the engine can achieve complete combustion at low speed, so even at very low speed, it can obtain large torque. The application of pre injection technology has made greater progress in recing emissions and noise
2 the fuel supply system precisely controls
the low-pressure oil pump sucks the diesel from the fuel tank and supplies it to the high-pressure oil pump through filtration. In the low-pressure pump, there is a solenoid valve to control the fuel to reach the high-pressure pump chamber, and the fuel enters the tubular accumulator fuel rail. There is a pressure sensor on the common rail to monitor the fuel pressure from time to time, and transmit this signal to the ECU, which controls the fuel pressure in the common rail to reach the desired value by adjusting the flow. The injection pressure varies from 200 to 1800 bar according to the engine operating conditions, and then is injected into the cylinder by computer control. The common rail not only maintains the fuel pressure, but also eliminates the pressure fluctuation
fuel injection is a complex combination of mechanical, hydraulic and electronic systems. In order to adapt to the working environment of the engine under various working conditions, the fuel must be filtered and pressurized before combustion, and injected into each cylinder at a certain injection rate at an accurate time. The engine computer controls the exhaust gas recirculation, supercharging and exhaust after treatment system to obtain the best engine characteristics and exhaust emissions
3 the latest generation of common rail engines
the compact structure of the injector makes the common rail system a practical solution even for small displacement 4-Valve engines. At the end of 1999, smart, equipped with a three cylinder common rail diesel engine, was born. Its displacement is only 799ml, its maximum power is 30kW, and its maximum output torque is 100nm at 1800-2800rpm
the second generation common rail engine is installed on the E320 launched by Benz this year. The maximum power is 150KW, the output torque is 250nm at 1000rpm, 85% of the peak torque can be obtained at 1400rpm, and the peak torque of 500nm can be achieved in a wide area of 1800-2600rpm. The acceleration time from 0 to 100 km / h is only 7.7 seconds, and the maximum speed is 243 km / h. The comprehensive fuel consumption is 6.9l/100km, and the enrance of 80L fuel tank reaches 1000km. The comprehensive fuel consumption of E320 with gasoline engine is 9.9l/100km
three generations of diesel common rail system have been developed, and it has a strong technical potential
the first generation of common rail high pressure pump is always kept at the highest pressure, resulting in energy waste and high fuel temperature. The second generation can change the output pressure according to the needs of the engine, and has pre injection and post injection functions. Pre injection reces engine noise: a small amount of fuel is injected into the cylinder compression ignition, pre heated combustion chamber within one millionth of a second before main injection. The preheated cylinder makes the compression ignition easier after the main injection, and the pressure and temperature in the cylinder no longer increase suddenly, which is concive to recing the combustion noise. During the expansion process, after injection, secondary combustion is proced, which increases the temperature in the cylinder by 200 ~ 250 ℃, and reces the hydrocarbon in the exhaust
e to its strong technical potential, today's manufacturers have focused on the third generation of common rail system piezo common rail system, in which piezoelectric actuators replace solenoid valves, thus achieving more accurate injection control. Without the oil return pipe, the structure is simpler. The pressure is adjusted elastically from 200 to 2000 bar. The minimum injection volume can be controlled at 0.5mm3, recing the smoke and NOx emissions
"electronic control" means that the fuel injection system is controlled by computer. ECU (commonly known as computer) precisely controls the injection quantity and injection time of each nozzle, which can achieve the best balance between fuel economy and power performance of diesel engine. However, the traditional diesel engine is controlled by machinery, so the control accuracy can not be guaranteed
"high pressure" means that the pressure of the injection system is three times higher than that of the traditional diesel engine, and the maximum pressure can reach 200MPa (while the injection pressure of the traditional diesel engine is 60-70mpa). The pressure is large, the atomization is good, and the combustion is sufficient, so as to improve the power performance and finally achieve the purpose of fuel saving
"common rail" is to supply each fuel nozzle through the common fuel supply pipe at the same time. The fuel injection quantity is accurately calculated by ECU. At the same time, it provides each fuel nozzle with the same quality and pressure of fuel, so as to make the engine run more smoothly and optimize the comprehensive performance of diesel engine. However, the traditional diesel engine injects fuel from each cylinder, the injection quantity and pressure are not consistent, and the operation is not uniform, resulting in unstable combustion, high noise and high fuel consumption
at present, domestic diesel engines with internationally advanced electronically controlled high pressure common rail technology have adopted the latest core technology of European and American diesel engines, which is obviously superior to traditional turbocharged diesel engines. Compared with the traditional turbocharged diesel engine, it has 8% higher combustion efficiency, 10% lower carbon dioxide emission and 15% lower noise, which completely changes the image of diesel engine as "noisy and smoky" in people's mind
4 structure principle and characteristics
the high-pressure common rail system uses a large volume of common rail cavity to accumulate the high-pressure fuel from the oil pump, eliminate the pressure fluctuation in the fuel, and then deliver it to each injector, and realize the start and end of injection by controlling the solenoid valve on the injector
its main features can be summarized as follows:
the high pressure in the common rail cavity is directly used for injection, which can eliminate the supercharging mechanism in the injector; The driving torque of high pressure oil pump is much smaller than that of traditional oil pump
through the pressure regulating solenoid valve on the high-pressure oil pump, the oil pressure in the common rail chamber can be flexibly adjusted according to the engine load condition and the requirements of economy and emission, especially the low-speed performance of the engine is optimized
the injection timing, injection quantity and injection rate are controlled by the solenoid valve on the injector, and the injection quantity of pre injection and post injection and the interval with the main injection under different working conditions can be flexibly adjusted
the high pressure common rail system consists of five parts: high pressure oil pump, common rail chamber and high pressure oil pipe, fuel injector, electronic control unit, various sensors and actuators. The fuel supply pump pumps the fuel from the fuel tank into the oil inlet of the high-pressure oil pump. The high-pressure oil pump driven by the engine pressurizes the fuel and sends it into the common rail cavity. Then the solenoid valve controls the injector of each cylinder to inject fuel at the corresponding time
pre injection before the main injection, a small part of fuel is injected into the cylinder, and pre mixing or partial combustion occurs in the cylinder, which shortens the ignition delay period of the main injection. In this way, both the rate of pressure rise and the peak pressure in the cylinder will decrease, and the engine will run smoothly
high pressure common rail EFI technology is a kind of fuel supply mode that separates the generation of injection pressure and injection process completely in the closed-loop system composed of high-pressure oil pump, pressure sensor and electronic control unit (ECU). The high-pressure fuel is delivered by the high-pressure oil pump to the common fuel supply pipe (rail), and the oil pressure in the common fuel supply pipe is precisely controlled, so that the pressure of the high-pressure oil pipe has nothing to do with the engine speed, which can greatly rece the change degree of the fuel supply pressure of the diesel engine with the engine speed.
common rail technology refers to the high-pressure oil pump, the high-pressure oil pipe, the high-pressure oil pipe and the high-pressure oil pipe In the closed-loop system composed of pressure sensor and ECU, the generation of injection pressure and injection process are completely separated from each other. The high-pressure fuel is delivered to the common fuel supply pipe by the high-pressure oil pump, and the oil pressure in the common fuel supply pipe is precisely controlled, so that the pressure of the high-pressure fuel pipe has nothing to do with the engine speed, It can greatly rece the change of fuel supply pressure with engine speed, so it can rece the defects of traditional diesel engine. ECU controls the fuel injection quantity of the injector, which depends on the pressure of the fuel rail (common fuel supply pipe) and the opening time of the solenoid valve
1 high pressure common rail technology
the common rail system separates fuel pressure generation and fuel injection. If the unit pump diesel injection technology is compared to the revolution of diesel technology, the common rail can be called a rebellion, because it deviates from the traditional diesel system and is similar to the sequential gasoline injection system. Common rail system opens up a new way to rece diesel engine emissions and noise
Europe can be said to be a paradise for diesel vehicles, with diesel cars accounting for 39% in Germany. Diesel car has a history of nearly 70 years, and in the last 10 years, diesel engine has developed rapidly. In 1997, Bosch and Benz jointly developed the common rail diesel injection system. Today, in Europe, many brands of cars are equipped with common rail diesel engines, such as Peugeot's HDI common rail diesel engine, Fiat's JTD engine, and Delphi's multec DCR diesel common rail system
the common rail diesel injection system is different from the previous diesel injection system driven by camshaft. The common rail diesel injection system completely separates the generation of injection pressure and injection process from each other. The traditional mechanical injector is replaced by the injector controlled by solenoid valve. The fuel pressure in the fuel rail is generated by a radial piston high-pressure pump. The pressure is independent of the engine speed and can be set freely within a certain range. The fuel pressure in the common rail is controlled by an electromagnetic pressure regulating valve, which continuously adjusts the pressure according to the working requirements of the engine. The pulse signal of ECU acting on the solenoid valve of injector controls the injection process of fuel. The amount of fuel injection depends on the oil pressure in the fuel rail, the opening time of the solenoid valve and the liquid flow characteristics of the nozzle
fuel injection pressure is an important index of diesel engine, because it is related to engine power, fuel consumption, emissions and so on. The common rail diesel injection system has increased the fuel injection pressure to 1800 bar
in the last two years, cars with direct injection diesel engine have been developed significantly in Europe, with high efficiency and excellent fuel economy, and reced engine noise. The direct injection diesel engine uses a pump nozzle system, which is used by the domestic 1.9tdi bora. The maximum injection pressure can reach 1800 bar. Although the pump nozzle direct injection system is good, the fuel pressure can not be kept constant. With the more stringent emission control, higher and constant diesel injection pressure and more perfect electronic control are needed. Therefore, many manufacturers regard the diesel common rail system with more advantages as the development direction of diesel engine. This system has high fuel pressure and can provide flexible fuel distribution control. It can flexibly control fuel distribution, fuel injection time, injection pressure and injection rate through ECU. Through the control of the above characteristics, the common rail has made the diesel engine's responsiveness and driving comfort reach the level of gasoline engine, at the same time, it has significant fuel economy and low emission characteristics
high fuel pressure can be ensured in all engine speed ranges, and high injection pressure can obtain good combustion characteristics at low engine speed.
for the engine with axial piston type distributing pump driven and controlled by camshaft, the fuel system pressure is linearly related to engine speed, which leads to insufficient fuel pressure at low engine speed, The common rail system can achieve very high fuel pressure in all engine speed ranges. Flexible electronic control system for timing and injection pressure control can achieve low emissions and high efficiency under various engine conditions. Because the formation of pressure is separated from the injection process, the engine designers have more freedom to study the combustion and injection process. The injection pressure and injection timing can be adjusted according to the requirements of the engine working conditions, so that the engine can achieve complete combustion at low speed, so even at very low speed, it can obtain large torque. The application of pre injection technology has made greater progress in recing emissions and noise
2 the fuel supply system precisely controls
the low-pressure oil pump sucks the diesel from the fuel tank and supplies it to the high-pressure oil pump through filtration. In the low-pressure pump, there is a solenoid valve to control the fuel to reach the high-pressure pump chamber, and the fuel enters the tubular accumulator fuel rail. There is a pressure sensor on the common rail to monitor the fuel pressure from time to time, and transmit this signal to the ECU, which controls the fuel pressure in the common rail to reach the desired value by adjusting the flow. The injection pressure varies from 200 to 1800 bar according to the engine operating conditions, and then is injected into the cylinder by computer control. The common rail not only maintains the fuel pressure, but also eliminates the pressure fluctuation
fuel injection is a complex combination of mechanical, hydraulic and electronic systems. In order to adapt to the working environment of the engine under various working conditions, the fuel must be filtered and pressurized before combustion, and injected into each cylinder at a certain injection rate at an accurate time. The engine computer controls the exhaust gas recirculation, supercharging and exhaust after treatment system to obtain the best engine characteristics and exhaust emissions
3 the latest generation of common rail engines
the compact structure of the injector makes the common rail system a practical solution even for small displacement 4-Valve engines. At the end of 1999, smart, equipped with a three cylinder common rail diesel engine, was born. Its displacement is only 799ml, its maximum power is 30kW, and its maximum output torque is 100nm at 1800-2800rpm
the second generation common rail engine is installed on the E320 launched by Benz this year. The maximum power is 150KW, the output torque is 250nm at 1000rpm, 85% of the peak torque can be obtained at 1400rpm, and the peak torque of 500nm can be achieved in a wide area of 1800-2600rpm. The acceleration time from 0 to 100 km / h is only 7.7 seconds, and the maximum speed is 243 km / h. The comprehensive fuel consumption is 6.9l/100km, and the enrance of 80L fuel tank reaches 1000km. The comprehensive fuel consumption of E320 with gasoline engine is 9.9l/100km
three generations of diesel common rail system have been developed, and it has a strong technical potential
the first generation of common rail high pressure pump is always kept at the highest pressure, resulting in energy waste and high fuel temperature. The second generation can change the output pressure according to the needs of the engine, and has pre injection and post injection functions. Pre injection reces engine noise: a small amount of fuel is injected into the cylinder compression ignition, pre heated combustion chamber within one millionth of a second before main injection. The preheated cylinder makes the compression ignition easier after the main injection, and the pressure and temperature in the cylinder no longer increase suddenly, which is concive to recing the combustion noise. During the expansion process, after injection, secondary combustion is proced, which increases the temperature in the cylinder by 200 ~ 250 ℃, and reces the hydrocarbon in the exhaust
e to its strong technical potential, today's manufacturers have focused on the third generation of common rail system piezo common rail system, in which piezoelectric actuators replace solenoid valves, thus achieving more accurate injection control. Without the oil return pipe, the structure is simpler. The pressure is adjusted elastically from 200 to 2000 bar. The minimum injection volume can be controlled at 0.5mm3, recing the smoke and NOx emissions
"electronic control" means that the fuel injection system is controlled by computer. ECU (commonly known as computer) precisely controls the injection quantity and injection time of each nozzle, which can achieve the best balance between fuel economy and power performance of diesel engine. However, the traditional diesel engine is controlled by machinery, so the control accuracy can not be guaranteed
"high pressure" means that the pressure of the injection system is three times higher than that of the traditional diesel engine, and the maximum pressure can reach 200MPa (while the injection pressure of the traditional diesel engine is 60-70mpa). The pressure is large, the atomization is good, and the combustion is sufficient, so as to improve the power performance and finally achieve the purpose of fuel saving
"common rail" is to supply each fuel nozzle through the common fuel supply pipe at the same time. The fuel injection quantity is accurately calculated by ECU. At the same time, it provides each fuel nozzle with the same quality and pressure of fuel, so as to make the engine run more smoothly and optimize the comprehensive performance of diesel engine. However, the traditional diesel engine injects fuel from each cylinder, the injection quantity and pressure are not consistent, and the operation is not uniform, resulting in unstable combustion, high noise and high fuel consumption
at present, domestic diesel engines with internationally advanced electronically controlled high pressure common rail technology have adopted the latest core technology of European and American diesel engines, which is obviously superior to traditional turbocharged diesel engines. Compared with the traditional turbocharged diesel engine, it has 8% higher combustion efficiency, 10% lower carbon dioxide emission and 15% lower noise, which completely changes the image of diesel engine as "noisy and smoky" in people's mind
4 structure principle and characteristics
the high-pressure common rail system uses a large volume of common rail cavity to accumulate the high-pressure fuel from the oil pump, eliminate the pressure fluctuation in the fuel, and then deliver it to each injector, and realize the start and end of injection by controlling the solenoid valve on the injector
its main features can be summarized as follows:
the high pressure in the common rail cavity is directly used for injection, which can eliminate the supercharging mechanism in the injector; The driving torque of high pressure oil pump is much smaller than that of traditional oil pump
through the pressure regulating solenoid valve on the high-pressure oil pump, the oil pressure in the common rail chamber can be flexibly adjusted according to the engine load condition and the requirements of economy and emission, especially the low-speed performance of the engine is optimized
the injection timing, injection quantity and injection rate are controlled by the solenoid valve on the injector, and the injection quantity of pre injection and post injection and the interval with the main injection under different working conditions can be flexibly adjusted
the high pressure common rail system consists of five parts: high pressure oil pump, common rail chamber and high pressure oil pipe, fuel injector, electronic control unit, various sensors and actuators. The fuel supply pump pumps the fuel from the fuel tank into the oil inlet of the high-pressure oil pump. The high-pressure oil pump driven by the engine pressurizes the fuel and sends it into the common rail cavity. Then the solenoid valve controls the injector of each cylinder to inject fuel at the corresponding time
pre injection before the main injection, a small part of fuel is injected into the cylinder, and pre mixing or partial combustion occurs in the cylinder, which shortens the ignition delay period of the main injection. In this way, both the rate of pressure rise and the peak pressure in the cylinder will decrease, and the engine will run smoothly
4. More accurate fuel injection, more environmentally friendly exhaust, but higher requirements for fuel quality is the development trend of diesel engine, which does not help much in power and fuel consumption. The sound of the machine is pleasant and the noise is low after landing
5. The three systems of engine electronic control should be sensors, ECU and actuators, which constitute the closed loop of fuel control to meet the requirements of power and emission
6. Electronically controlled fuel injection system (electronically controlled gasoline injection system, high pressure common rail electronically controlled diesel injection system), oxygen sensor, three-way catalytic converter, feedback control system, variable intake device (variable valve timing, variable valve lift, variable intake manifold length, closed cylinder fuel saving, etc.), exhaust gas recirculation device, forced crankcase ventilation device, gas evaporation control device, etc
automobile engine is the engine that provides power for automobile and the heart of automobile, which affects the power performance, economy and environmental protection of automobile. According to different power sources, automobile engine can be divided into diesel engine, gasoline engine, electric vehicle motor and hybrid power
common gasoline engines and diesel engines are reciprocating piston internal combustion engines, which convert chemical energy of fuel into mechanical energy of piston motion and output power to the outside. Gasoline engine has high speed, low quality, low noise, easy starting and low manufacturing cost; Diesel engine has higher compression ratio, higher thermal efficiency, better economic performance and emission performance than gasoline engine
in addition to gasoline and diesel, other new energy vehicles are called new energy vehicles, including pure electric vehicles, hybrid electric vehicles, fuel cell vehicles, gas vehicles, bioethanol / biodiesel vehicles and hydrogen vehicles. Most of the new energy vehicles on sale in China are hybrid electric vehicles, but at present, pure electric vehicles have been taken as the main direction
control system is a management system with its own goals and functions, which is composed of control subject, control object and control media
control system means that it can keep and change any interesting or changeable quantity in the machine, mechanism or other equipment in the desired way. At the same time, the control system is implemented to make the controlled object reach the predetermined ideal state. The control system makes the controlled object tend to a desired stable state
for example, suppose there is a driving system of a car, and the speed of the car is a function of its accelerator position. The desired speed can be maintained (or the desired speed change can be achieved) by controlling the pressure of the accelerator pedal. The driving system of the car (accelerator, carburetor and engine vehicle) forms a control system.
automobile engine is the engine that provides power for automobile and the heart of automobile, which affects the power performance, economy and environmental protection of automobile. According to different power sources, automobile engine can be divided into diesel engine, gasoline engine, electric vehicle motor and hybrid power
common gasoline engines and diesel engines are reciprocating piston internal combustion engines, which convert chemical energy of fuel into mechanical energy of piston motion and output power to the outside. Gasoline engine has high speed, low quality, low noise, easy starting and low manufacturing cost; Diesel engine has higher compression ratio, higher thermal efficiency, better economic performance and emission performance than gasoline engine
in addition to gasoline and diesel, other new energy vehicles are called new energy vehicles, including pure electric vehicles, hybrid electric vehicles, fuel cell vehicles, gas vehicles, bioethanol / biodiesel vehicles and hydrogen vehicles. Most of the new energy vehicles on sale in China are hybrid electric vehicles, but at present, pure electric vehicles have been taken as the main direction
control system is a management system with its own goals and functions, which is composed of control subject, control object and control media
control system means that it can keep and change any interesting or changeable quantity in the machine, mechanism or other equipment in the desired way. At the same time, the control system is implemented to make the controlled object reach the predetermined ideal state. The control system makes the controlled object tend to a desired stable state
for example, suppose there is a driving system of a car, and the speed of the car is a function of its accelerator position. The desired speed can be maintained (or the desired speed change can be achieved) by controlling the pressure of the accelerator pedal. The driving system of the car (accelerator, carburetor and engine vehicle) forms a control system.
7. Hello, the country is now promoting the proction of cars require electronic control engine, improve exhaust pollution to the environment. The electronically controlled engine has closed loop control. Real time monitoring engine power at a certain time, and improve it. Control the amount of oil. Rece fuel consumption. More clear computer control of the system and provide you with information
8. According to your description. When the engine control system needs closed-loop control. Engine control is divided into open-loop control and closed-loop control. How many conditions are there for the main timing of closed loop control? One. The engine must reach normal working temperature. Two. The load and speed requirements of the engine must meet the requirements (1000-4000) of non urgent addition and subtraction state. Third, the sensors related to closed-loop control must be normal. Such as oxygen sensor. Burst sensors, etc. It is suggested to learn the relevant materials and hope to adopt them.
9. The answer is concise and correct< The main control methods are as follows:
1. Injection quantity
2. Injection timing
3. Ignition control
4. Idle speed control
5. Fuel pump control
6. Carbon canister solenoid valve control
7. Emission post-treatment system control (EGR, SCR, etc.)
8. Implementation of OBD function
9. Fault diagnosis
with the increase of new automobile and engine technologies, The contents of driving computer control are also increasing, and now there are supercharging control, variable timing control and so on.
1. Injection quantity
2. Injection timing
3. Ignition control
4. Idle speed control
5. Fuel pump control
6. Carbon canister solenoid valve control
7. Emission post-treatment system control (EGR, SCR, etc.)
8. Implementation of OBD function
9. Fault diagnosis
with the increase of new automobile and engine technologies, The contents of driving computer control are also increasing, and now there are supercharging control, variable timing control and so on.
10. The goal of electronic control is to achieve low emissions, rece fuel consumption and appropriate idle speed, comfortable driving performance, and also provide the ability of electronic anti-theft
the method is to measure the engine speed, working condition, air intake quantity, water temperature, air intake temperature and whether the auxiliary engine is working through various sensors, and then determine the appropriate fuel supply quantity (injection time, pulse width) and ignition time through the program comparison with the data table stored in the computer board, so as to ensure the good operation of the engine. By monitoring the oxygen concentration of the exhaust gas from the engine, the fuel injection parameters are corrected to rece the harmful exhaust emissions.
the method is to measure the engine speed, working condition, air intake quantity, water temperature, air intake temperature and whether the auxiliary engine is working through various sensors, and then determine the appropriate fuel supply quantity (injection time, pulse width) and ignition time through the program comparison with the data table stored in the computer board, so as to ensure the good operation of the engine. By monitoring the oxygen concentration of the exhaust gas from the engine, the fuel injection parameters are corrected to rece the harmful exhaust emissions.
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