|Modern Common Rail Diesel Engine EFI new technology|
Summary: In this paper, the modern car engine electronic control system with the development of purpose, significance and the status quo; focuses on the modern car engine electronic control systems (including time control diesel EFI, Common Rail EFI, in the turbocharged Cold, EGR) of the new technology at the same time pointed out the new Common Rail EFI technology is the future of modern diesel engine car the inevitable trend of development.
Key words: Common Rail Diesel Engine Electronic Control System-EFI new technology
1. Diesel Engine Electronic Control System Development
Hyundai Motor gasoline and electrical control technology development background, unavoidable in the face of local and global environmental and energy issues, the modern diesel engine vehicles to use and the development of electronic control systems, in order to maintain the sustainable development of diesel engine vehicles, give full play to the inherent advantages of diesel engine (low fuel consumption and low CO2 emissions). Maintain excellence in diesel engine fuel economy at the same time, in order to meet increasingly stringent emissions regulations, in addition to reducing oil consumption, optimized turbocharger technology and the use of advanced exhaust after-treatment system, the main engine of the need to be further improved combustion process. The fuel injection system performance impact of diesel engine combustion process is the key, using micro-electromechanical control technology to improve the combustion process of many new technologies, although some new technology and electronic control technology did not directly linked, but to improve the overall performance, Electronic technology and still have an indirect link.
Diesel Engine Electronic Control Technology and the development of the electrical control system similar to gasoline. Since the 1980s, has begun to enter the market Hyundai diesel engine with electronic control system is the growing number of project control, control tasks from simple to complex, until all control. For example, the early electronic-controlled fuel injection system used a "position control," maintaining a traditional pulsed high voltage supply principle, but through a computer control unit at the core of the position servo control and change the fuel adjustment Rack ( inline pump), or fuel adjustment sleeve (VE-distribution pump), the location of the fuel pump to adjust for the cycle (jet) fuel. However, as institutions position servo slow implementation of the frequency response, low frequency control, control precision instability, after nearly a decade of development, 1980s and early 1990s, "Time control" electronically controlled fuel-injection system developed using the powerful new high-speed Electromagnetic valve instead of the traditional oil-conditioning rack (inline pump), or fuel adjustment sleeve (VE-distribution pump), high-pressure fuel directly to a digital high-frequency adjustment, from the closure of the solenoid valve closure time and duration for the decision cycle (spray) and for oil (spray) when the oil is. Nevertheless, this "time control" electronically controlled fuel-injection system remains the traditional principle of pulsed high voltage supply. Until the mid-1990s, a new type of electronically controlled common rail fuel injection system was made to abandon the traditional pulsed high voltage supply principle, the "time - pressure control" of the fuel metering principle, the public through hydraulic oil in the track Continuous control and the process of the cylinder fuel injection control solenoid valve to achieve a combination of the cycle for the (jet) fuel control, and the only diesel engine electronic control of fuel injection technology has entered a new stage of development.
Diesel Engine Electronic Control Technology also facing many issues that need to be resolved, especially when using high-voltage controlled fuel injection, diesel engine electronic control system costs accounted for almost half of the cost of the engine. Nevertheless, only in the automotive diesel engine electronic control technology widely used to the face of increasingly stringent emissions regulations challenges. Diesel electric control system in recent years the development momentum is remarkable. The use of diesel vehicles to a maximum of Europe, for example, the European road vehicles with multi-cylinder diesel engine from the beginning of 2000 emission standards for the implementation of the EU 3, the electronic control technology has been in Europe to meet the three standards on the widespread use of diesel engines, some research institutions and large the manufacturers have already begun to meet the EU-4 emission standard electronically controlled diesel engine, now electronically controlled common rail system and the electronic control unit pump system in the application of multi-cylinder diesel engine has been significantly increased.
China on modern diesel engine electronic control technology research and development is still at an early stage, is still mainly focused on Diesel Fuel Injection System for research and development. But with economic and social development, environmental protection becoming more demanding, Diesel Engine Electronic Control System for the development and the corresponding products will become China's automotive diesel technology in the area of a hot spot, which will greatly promote China's automotive diesel engine product updates updating, and in the future for a long period does not participate in international competition and lay a solid foundation.
2. Modern car engine electronic control system of new technologies
Time control of the diesel engine technology of the new generation of EFI EFI system uses time-control, high-speed solenoid valve used to replace the traditional mechanical spray valve on the high-pressure fuel the digital regulation. This injection system is now gradually moving toward a high-pressure, high-pressure spray atomization can very small diesel engine combustion process quite well and fast, without significantly enhancing the combustion temperature. Increased pressure direct injection diesel engine, it can not only comprehensively reduce HC, CO and NOx, and particulates of soot emissions, but can also significantly reduce fuel consumption.
EFI system in the Common Rail Diesel Engine, high-speed operation of the diesel injection process only 0.07 seconds time in the course of high-pressure injection tubing pressure throughout with time and location of the different change. As diesel compressibility and high pressure tubing pressure fluctuations in diesel, the actual fuel pump and injector status under the law of supply plunger greater difference. Tubing, sometimes the pressure fluctuations in the main jet, so that the pressure within the high-pressure pipeline rose again, reaching the injector pressure to open the valve, the valve has been closed and reopened the secondary injection phenomenon, Because it is impossible to burn the second injection, so an increase of smoke and hydrocarbons (HC) emissions, fuel consumption increases. In addition, each spray cycle of the high-pressure pipeline residual pressure will change the ensuing instability arising from the jet, especially in the low-speed region prone to this phenomenon, not only serious injection uneven, but will not spray in intermittent phenomenon. To address this diesel engine fuel pressure changes shortcomings, the modern use of a diesel engine known as the "Common Rail" technology.
It is the engine of a high-pressure injection system, the maximum pressure of 200 to 220 MPa. The system is no longer the pulse of a universal principle, but instead used the time pressure measurement principle. "Common Rail Injection" is the common high-pressure cylinder oil, and jet solenoid valve control to achieve a combination of fuel injection control. This injection system can guarantee that with the injection pressure not to the number of engine changes, which reduces particulate emissions, electronically controlled common rail injection pressure of time is also known as the third-generation jet or jet, which can be divided into pressure in the common rail and High Pressure Common Rail two categories. ECU electrical pulse generated sequentially trigger injector solenoid valve to determine each injection engine and the closure of the initial moment, electronically controlled common rail injection can be used repeatedly spray approach to the flexible control of fuel injection rate. The United States, Japan, Germany, Italy, and other countries have large-volume production of EFI common rail system, which will on behalf of the future of the diesel engine fuel injection system mainstream. Germany Mercedes-Benz C200 sedan, a Common Rail EFI system, its power, torque and emissions, and other indicators in the world leading level. Computer Control of High Pressure Common Rail Diesel injection system shown in figure 1.
Turbocharged diesel engine using technology in the cold exhaust turbocharger technology, to fuel combustion, which reduces CO and HC of the formation. But inlet temperature increased, the NOx emissions has increased, the use of booster and fringe intercooler may also reduce HC, CO and NOx emissions. In the cold by turbocharged diesel engine technology can improve power, with a turbo-diesel engine power output than not installed supercharger to increase 20% to 30%, while use of technology and even turbo-charged 50% of the increased power. New Turbocharger the use of means that can be used in small-displacement engine alternative, larger engines, reducing the engine and vehicle quality, improve the economy and emissions of.
Multi-valve technology can be multi-valve diesel engine increases the feed rate, the diesel combustion more thoroughly exhaust faster and more thoroughly so as to enhance the output power of the diesel engine.
EGR technology is the engine driving force in the performance guarantee under the premise of not lower, according to the engine temperature and load size, suitably emissions will be part of the introduction into the trachea and then into the cylinder so that the combustion reaction has slowed, the lower the maximum combustion temperature , thus reducing NOx emissions. EGR especially in the cold, not only to reduce NOx emissions, but will also maintain its pollution emissions from the low-emission standards.
New clean up diesel engine electronic control system technology in the foreign application rate has reached 60% to 90%. 20 beginning in the 1980s put on the market, the German company Bosch, the United States GM's Detroit Diesel Corporation, Japan Zexel company has its own products on the market. At present major companies competing to develop new products to meet emissions regulations, and market requirements. Electronically Controlled Diesel Engine technology, the development of technology to improve power from the diesel engine of the economy, the biggest impetus from the international community increasingly stringent emissions regulations. Peugeot company recently developed a new type of diesel engine decontamination systems, will be opened in recent years, the veil of its flagship car, the car will be equipped several engine, a 2.2 L of HDI diesel engine will be equipped with the unique breathing carbon filtration systems. Peugeot - Citroen company said the technology in the development of HDI engine of the new system can effectively overcome the particulate emissions from this dilemma. The system allows HDI engine emissions of carbon dioxide by 20 percent, carbon monoxide by 40%, hydrocarbons by 50%, while the particles can be reduced by 60%. Been known since the advent of the diesel engine biggest innovation. It is learnt that the particulate filter system has been adopted by France, Germany and the approval of the environmental sector, so that the technology has aroused the attention of Europe. Over the years, filtered solution is considered one of the ways in diesel engine exhaust. New filters enable HDI engine management systems and computer sensors to detect particles accumulate status, and the timely switch will automatically trigger particles burn out. Such filtering device in the next five years, if market acceptance, it will be extended to all Peugeot Citroen diesel cars and light commercial vehicles on. Particulate traps on the car had no effect on the performance of the original. HDI engine fuel consumption may rise at 5%, but performance compared with similar engines has increased by 15 per cent. This shows that the overall owners are still cost-effective. At present diesel vehicles sales in Europe to grow by about 1% a year, if as technology advances, more and more diesel vehicles acceptable to the vast number of consumers, its sales will grow by 2% to 3%, and the particulate filter system can accelerate this process. According to statistics of diesel vehicles currently account for about Europe minibus number of 25 per cent. PSA particulate filter system will be installed in the first new Peugeot car, and sales have been weak for the renewal of the Peugeot 605 series. Equipped with the filtration system DWl2TED4 models for the 2.2 L engine, up to 110.4 kW power output torque of 315 N m, than the current level of 2.5 L diesel engine performance okay.
3. Common Rail EFI new technology is a modern diesel engine car the inevitable trend of development
With the world's urban transport vehicles States, the dramatic increase in ships, diesel engine exhaust emissions on the Earth's environment has become the main source of pollution. Countries around the world have started looking for the technology and to take effective measures to take the initiative to reduce and control the emission of pollutants. Common Rail Diesel Engine Electronic Fuel Injection technology is a more successful pollution control emissions from new technologies. Electronically controlled common rail fuel injection common rail technology, directly or indirectly, through the formation of a constant high-pressure fuel delivered to each injector, and the help of integration in each injector switch on the high-speed electromagnetic valve open and closed , time, and quantity control of the injector jet fuel to the engine combustion chamber, thus ensuring the best diesel engine combustion ratio and good atomization, and the best time of the ignition, the ignition enough energy and the least polluting emissions. The new technology has now begun to foreign Diesel-powered vehicles in use. This is the world auto industry to meet the increasingly stringent emission standards of an inevitable trend.
Common Rail Diesel Engine Electronic Fuel Injection technology is a new technology, because it integrates computer-controlled technology, modern sensor detection technology and advanced fuel injection in a structure. The main features of the technology are: the application of advanced electronic control devices and equipped with high-speed Solenoid Valve; way using common rail fuel supply and a high-speed high-frequency electromagnetic on-off valve, control flexible system architecture to facilitate transplantation, to a wide range. Research and development of this technology is hot: High Pressure Common Rail System to resolve the constant high-pressure sealing; solution High Pressure Common Rail system, the common rail pressure fluctuations caused by small volume injection uneven; solution High Pressure Common Rail System Multi-MAP (three-dimensional control data table) optimization problem and solution structure, switching frequency electromagnetic valve design and manufacturing process of the key technical issues. Common Rail Fuel Injection technology can help reduce diesel exhaust emissions, and to improve noise, fuel consumption and other aspects of the comprehensive performance; it conducive to the global environment, but it also will promote diesel engine industry, the auto industry and with the development of related industries.
High-pressure common rail technology is the means, pumps, pressure sensors and closed-loop system composed of ECU, will be the selection of injection pressure and injection process in a completely separate their supply, high-pressure pumps from the high-pressure fuel pipeline for conveying to the public, Through the public for the hydraulic tubing to achieve precise control, high-pressure tubing pressure size has nothing to do with the engine speed, engine oil can be drastically reduced pressure with engine speed changes, therefore, you reduce the shortcomings of the traditional diesel engine. ECU control the injector fuel injection quantity, depends on the size of the fuel injector rail (public for tubing) solenoid valve opening pressure and the length of time. Electronically controlled common rail fuel injection common rail technology, directly or indirectly, through the formation of a constant high-pressure fuel delivered to each injector, and the help of integration in each injector switch on the high-speed electromagnetic valve open and closed , time, and quantity control of the injector jet fuel to the engine combustion chamber, thus ensuring the best diesel engine combustion ratio and good atomization, and the best time of the ignition, the ignition enough energy and the least polluting emissions. Common Rail Fuel Injection Device was successfully developed in recent years is that the ideal of a high-pressure fuel injection devices. In a shared track and the pressure of injection, respectively. Injection pressure can be as high as 16 O MPa. Its pressure on memory and distributor of rail Transcatheter to mouth. Use the controller to a pulse signal injection into the solenoid valve caused a jet. Through the nozzle pressure and open storage duration to regulate fuel. Currently, the various devices in the European automotive diesel engine have been widely used, and experts believe that this is a Europe able to meet future Ⅳ, Europe V the most potential for improvement of fuel injection devices. At the same time, reducing the nozzle diameter, to increase the number reduced nozzle hole diameter, a few more holes, can improve fuel atomization and uniformity of the distribution, reducing ignition delay, reduce particulate emissions and NO.
In recent years just commercialization of Common Rail fuel injection system to provide high injection pressure, but there will not be abnormal control of the jet, but also effectively reduce noise and nitrogen oxides emissions. Common Rail high-pressure fuel injection system for diesel technology is a revolution. The new technology has now begun to foreign Diesel-powered vehicles in use. This is the world auto industry to meet the increasingly stringent emission standards of an inevitable trend.
Bulky, noisy, smoky, the diesel engine is a poor impression of intuitive, and more complex structure Diesel, and many people lack an understanding of the diesel engine, particularly on modern art diesel lack of understanding, diesel vehicles in some cities a "limited," and face all kinds of discrimination. In fact, after many years of research and application of new technologies, the situation has been in modern diesel engine with the same metaphor of the past, diesel cars in Europe is relatively common, Mercedes-Benz, Volkswagen, BMW, Renault, Volvo, and other European brand cars have diesel engines models. After years of research and application of advanced modern diesel engine vehicles generally use EFI, common-rail, turbo in the cold, and other technical means, in the weight, noise, smoke, etc. has been made a major breakthrough, reaching the level of gasoline engine .
EFI in the area of diesel and petrol are the main differences between gasoline machine EFI system is air-fuel ratio control (the ratio of air and gasoline), diesel EFI system by controlling the fuel injection is time to adjust the size of the output, and the diesel engine fuel injection engine control by the speed and accelerator pedal position (drawbars throttle position) to decide. Thus, the basic principle is the basis of computer speed sensor and throttle position sensor input signals, first calculate the basic fuel injection quantity, and then under water temperature, inlet temperature of the air pressure sensor signal amendment, and again from the control sets Position sensor signal feedback amendment, to determine the optimum amount of fuel injection.
Electronic diesel injection system consists of sensors, ECU (computer) and the implementing agencies, and other components. Its mission is to electronically controlled fuel injection system, fuel injection volume, and the realization of the injection timing with the operating status of the real-time control. Using speed, temperature, pressure sensors, real-time detection parameters will be entered into the computer simultaneously, and had been stored values of the parameters of comparison, has been treated in accordance with the calculation of the best value on the fuel pump, exhaust gas recirculation valve, such as preheating Cypriot implementing agencies control, driven fuel injection system to achieve the best diesel engine operating status.
With the world's urban transport vehicles to the sharp increase in diesel engine exhaust emissions on the Earth's environment has become the main source of pollution. Countries around the world have started looking for the technology and to take effective measures to take the initiative to reduce and control the emission of pollutants. Common Rail Diesel Engine Electronic Fuel Injection technology is a more successful pollution control emissions from new technologies.