An electronic engine control technology and the development of the development trend

1.1 Diesel Engine Electronic Control Technology Development

Diesel Engine Electronic Control Technology began in the 1970s, during the 1980s, the British company Lucas, the German company Bosch, Mercedes-Benz automobile company, General of the Detroit Diesel Corporation, Cummins, Caterpillar, Japan 50 Ling Motor Co. and Komatsu produced by all competing to develop new products to market and to meet increasingly stringent emissions regulations.

As a high-torque diesel engine, high life expectancy, low fuel consumption, low emissions, and other characteristics of a diesel engine vehicles and construction machinery to resolve the issue of energy the most realistic and most reliable means. Therefore the use of diesel-growing, an increasing number. At the same time the dynamic performance of the diesel engine, the economic performance of emission control and noise pollution requirements are also getting higher and higher. Rely on the traditional mechanical control fuel injection system has been unable to meet the above requirements, it will be difficult to achieve injection volume, pressure and jet fuel injection is the best time in light of the requirements of operating conditions. In recent years, with computer technology, sensor technology and the rapid development of information technology, electronic products so that the reliability, cost, size and other aspects of diesel engines can meet the requirements for electronic control, electronically controlled fuel injection and are easy to implement.

In fact, diesel exhaust in the CO and HC far less than the gasoline engine, NOX emissions and gasoline engine similar, but more exhaust particles, and the mechanism of the combustion engine. Diesel is a non-homogeneous combustion, flammable mixture formed a very short time, and combustible gas mixture formation and combustion process intertwined. Diesel fuel injection through the analysis of the law are: injected into the atomization of fuel quality, the flow of gas cylinder in the shape of the combustion chamber and so directly affect the combustion process and the progress of the formation of harmful emissions. Improve the atomization of diesel fuel injection pressure and effect, the use of pre-spray, spray, can be sub-effective to improve emissions.

After years of research and new technology application, the status of diesel has been very different from the past. Modern diesel engines generally use EFI, high-pressure common-rail, turbocharged in the cold, such as technology, in weight, noise, smoke, and so has made a major breakthrough, reaching the level of gasoline engines. As the world increasingly stringent emission control standards (such as the European ¢ô, ¢õ standards) the promulgation and implementation of both the gasoline engine or diesel engines are faced with severe challenges, one solution is using electronic control fuel injection technology. Now, electronic engine control technology developed in the application rate has reached more than 60 percent.




What is the EFI 1.2 Diesel

Use electronic fuel injection and control the emission of diesel engine is the EFI. EFI diesel injection system of sensors, ECU (computer) and executive bodies of three parts. Its task is to control the conduct of electronic fuel injection system, and the fuel injector and injection timing of the operation condition of the real-time control. Used speed, throttle pedal position, injection time, into the temperature, air pressure, oil temperature, cooling water temperature sensor, real-time detection of parameters at the same time entered into the computer (ECU), and saved the set parameters or parameters Map (MAP) for comparison, has been treated in accordance with the best calculation of the value or terms of the order to Goal Value actuators. According to directives for the implementation of ECU fuel injection control of (the oil supply rack location or duration of the electromagnetic valve closed) and the injection is when (when the control valve is open or closed solenoid valve closed starting point), while the exhaust gas recirculation valve, preheat Cypriot control, such as implementing agencies, to achieve the best engine running.





1.3 Diesel Engine Electronic Control technology development trends

1.3.1 high-pressure spray

To meet the requirements of emissions regulations, diesel fuel injection pressure from 10 MPa to 200 MPa. The high pressure spray can improve the mix of diesel and air quality, shorten the period of delay on fire, burning more rapidly and thoroughly, and the control of combustion temperature, thereby reducing emissions.

1.3.2 independent injection pressure control

The traditional diesel engine fuel injection system of the jet engine pressure and the speed of the load. Such characteristics of the low-speed, under the conditions of the partial load fuel economy and emissions disadvantage. If the oil supply system is not dependent on speed and load the injection pressure control, you can select the most suitable injection pressure to spray duration, delayed ignition of the best, so that diesel engines in various condition of the economy and the lowest emission of optimal .


1.3.3 improve diesel fuel economy

Users of diesel fuel consumption rate of great concern. High-pressure jet, an independent injection pressure control, small nozzle, the average high-pressure fuel injection and other measures can reduce fuel consumption, thereby enhancing the use of diesel fuel economy.


1.3.4 is an independent, control of fuel injection

When the jet is a direct impact on Detroit Diesel on the only point before the fuel injected into the cylinder, the cylinder is determined by the highest peak outbreak of pressure and temperature. High cylinder pressure and temperature can be used to improve fuel economy, but led to an increase NOX. Rather than rely on speed and load when the jet is control, is in fuel consumption and emission rates to achieve the best balance between the key measures.


1.3.5 variable control of the pre-jet

Pre-spray can reduce the particulate emissions, not increase NOX emissions, but also improve the performance of diesel cold start and reduce Cold condition of white smoke emissions, reduce noise and improve low-speed torque. However, pre-jet volume, pre-jet and main jet in the time lag between the different conditions of the request is not the same. So with the pre-variable control of the jet engine performance and emissions very favorable.


1.3.6 minimum ability to control oil

Oil supply system with high pressure jet engine idling and the capacity needed to control small oil contradictions. When the fuel supply system has the ability to pre-spray will make the control of small oil capacity further reduced. Because of construction machinery diesel engine condition is very complex, often idling conditions, and easy to achieve the minimum of EFI diesel fuel control.


1.3.7 quick off oil capacity

Jet at the end of the oil must be broken quickly, if not quickly broken oil, in low-pressure spray of diesel will be full and not because of burning black smoke, increase the HC emissions. EFI diesel fuel injector on the use of high-speed electromagnetic valve switch is easy to achieve quick off the oil.

1.3.8 reduce the impact load drive torque

Fuel injection system at a very high work under pressure, not only to increase the drive system required by an average of torque, is also growing impact load. Fuel injection system to drive a smooth loading and unloading capacity is a measure of the standard injection system. EFI and diesel technology in the high-pressure common rail technology will greatly reduce the impact of the drive torque loads.






2 Diesel Engine Electronic Control Technology of the purpose and advantages


Objective 2.1

Dynamic Optimization of the use of improved fuel economy, emissions control, engine idling to the rated speed from within can get the best working conditions to prevent the possible outbreak of dangerous operation of extending the service life of components.

2.2 Benefits

2.2.1 a multi-functional performance of the automatic adjustment

Construction machinery with the engine running condition is changing, but also for fuel consumption, emissions and higher reliability. Automatic control technology in diesel-conditioning systems can be achieved-just the automatic adjustment to ensure that diesel power, fuel economy, reliability and ease of operation and other properties into full play.


2.2.2 reduce the quality and decrease the size and improve the compactness of the diesel engine

To the modern high-speed diesel engines, since the fuel pump drive greater torque, to design a compact and reliable oil supply ahead of the regulator is very complicated, but in general layout engine is also more difficult. Use of automation technology to solve supply advance angle automatic adjustment problems, not only can easily solve these problems, and improve the engine of the compact.

2.2.3 will be installed to facilitate connectivity and enhance the maintenance of

Use of automatic control systems, reduce the size of related components (especially the fuel supply system), the installation site from the location of the space constraints, connectivity is simple, is conducive to routine maintenance and repair of diesel engines.

2.2.4 expansion of the fault diagnosis, liaison function

Use of automatic control system, can be easily connected with the micro-computer, it is easy to achieve engine performance test and fault diagnosis function, and operation of diesel engine testing data storage and transmission, and other problems solved, for scientific management and use.

2.2.5 so that the engine power output and load more precise match

With the rapid construction machinery manufacturing technology development, in order to enhance self-construction machinery operating performance, using the EFI engine, electronically controlled automatic transmission, such as automatic control device so that the self-construction machinery in operation, we can load with the changes in Certain range automatically adjust power output, power transmission, the engine power output and load more precise match, give full play to construction machinery operating performance.







3 Diesel Engine Electronic Control Technology features

Diesel Engine Electronic Control Technology and petrol electrical control technologies have many similarities, the whole system by the sensors, electronic control modules and for the implementation of three components. EFI in diesel and gasoline engines in the main difference is that the gasoline engine is electronically controlled injection system controlled air-fuel ratio (the ratio of air and gasoline), diesel EFI system is by controlling the fuel injection time to adjust the output of oil Size, and diesel engine fuel injection control by the speed and accelerator pedal position (the accelerator, oil supply tension bar location) to decide. Diesel Engine Electronic Control Technology has two distinctive features: First, electronically controlled diesel injection for the implementation of complex and the second is electronically controlled diesel injection system of diversification.

3.1 Diesel is a relatively high thermal efficiency of power machinery

Diesel fuel injection with high-pressure, high-frequency, pulse and other characteristics. Its injection pressure of up to 200 MPa, for the gasoline engine jet pressure of more than 100 times. High-pressure fuel injection system for the implementation of electronic fuel injection control, much more difficult. Diesel and jet spray is on the high accuracy, compared to only point on the Detroit Diesel the perspective of location accuracy requirements than the gasoline engine, which led to a diesel injection for the implementation of the electronic control much more complex.


3.2 As the diesel injection system in various forms

Inline with the traditional diesel engine pumps, distribution pumps, fuel injection pump, single-cylinder pumps, and other structures completely different system. The implementation of electronic control technology is more complicated the implementation agency, formed a diesel injection system of diversification at the same time the need for diesel fuel, timing, injection pressure, and other parameters of a comprehensive control, the difficulty of its software is also greater than gasoline engines.






4 electronically controlled diesel injection system classification

There is the first electronically controlled fuel pump technology, and then developed the electronic control pump nozzle injection technology and high-pressure common rail technology, after the two technologies is now the main engine EFI technology. The electronically controlled fuel injection pump nozzle technology pressure is very high, can reach 200 MPa, and pumps and nozzles installed together, so only a very short guide of the high-pressure oil, pump nozzle systems can also achieve a very small amount of pre-jet, The injection of a triangle, and the use of sub-pre-spray, this is very consistent with the requirements of diesel engine (Volkswagen TDI engine is the use of such technology). However, electronically controlled fuel injection pump nozzle technology pressure affected by the diesel engine speed, the use of pressure with the high-pressure common rail system technology can solve this problem. It's lower than the pump nozzle injection pressure systems, can reach 160 MPa. Some companies look to its arbitrary number of engine cylinder fuel injection pressure regulator is very broad characteristics, and gradually expand its scope of use (the first to use the high-pressure common-rail cars is the Alfa Romeo 156 and Mercedes-Benz C-level cars).

The first generation of electronically controlled diesel engine fuel injection system also known as position control system, electronic servo mechanism to replace mechanical governor control oil supply in order to achieve Huatao location of the adjustment. Its characteristics are to retain the traditional fuel pump - high-pressure pipeline - injector systems, Huatao only on the rack or the movement from the original location of the mechanical governor control to computer control. Such technology has been developed to control both the timing and pre-spray the TICS system.