Diesel engine market in foreign countries developed rapidly, mainly due to people's awareness of environmental protection has been strengthened by diesel engines as the driving force of the car rapid growth, this trend is reflected not only in Europe, but also in the world.
Worldwide sales of light duty diesel vehicles by 2015 from 2004's 12.5 million to 27 million. 6 O% of which is in the European car market outside the main sales growth, from North America cars and light trucks sales ratio in the next 12 years from the current 4.5 percent raised to six percent.
At present, the Volkswagen diesel cars in North America, sales highest, and the other almost the same as OEM, they are also looking for new technological innovations.
The company Many researchers suggest that in the next 3 O years, the gasoline engine and diesel engine cars is still the main driving force, there are still many technical problems and human factors waiting to capture. The company developed from 1976 to the first turbo direct injection (TDI) engine, the diesel engine in the field has been in a leading position in U.S. sales of the Jetta (Jetta), golf (Golf) and the new Beetle (New Beetle) the total sales of diesel cars accounted for the 1 O%.
In order to maintain living in the North American market share of diesel cars, the public company intends to expand its product range, introduce new Touareg (Touareg) SUV and Phaeton (Phaeton) luxury sedan. Both models of the engine for 5, OL V1U power of 230 kW, twin-turbo direct injection engine speed in 2000 r / min, torque to 750 Nm. Engine by two rows of five independent of the cylinder through the machinery and electronic means and progress, connecting both sides of the exhaust. Cylinder and the distance between the cylinder is 88 mm bore and stroke are 81 mm and 95.5 mm.
Head of the basic design is a small engine as the basis for development, V1 0 engine cylinder head design for the cross-cutting re-shape to meet the two rows between the cylinder into the trachea requirements. Alternator and water pump assembly V-word, no lateral force through the drive shaft when the driver control. The engine is aluminum crankcase, with a gray cast iron bearing channel due to burning of the box in the crankcase deformation. Therefore, the Tianjin FAW Xiali Co., Ltd. Lin public companies, such as the use of ion plating method will review the cylinder wall painted coating. This method is developed by the public, and the first plasma Tudu methods used in the production of the diesel engine, the cylinder walls painted in about O 1-mm coating, so that the cylinder "long" resistance gas Cylinder deformation and wear.
V10 TDI engine used Bosch third-generation 5-nozzle, it has a very compact electromagnetic valve, can increase the injection pressure of the load. Two electronic control device to control fuel injection pressure to 2050 bar above, from the injector directly injected into the cylinder. It has two electronic control, electronic control devices each have a 32 bytes of microprocessors, control each cylinder row to drive better and function of dynamic performance and emission characteristics suit. V1OTDI engine injection system from 1 O independent pump nozzle of the fuel injector components, fuel injector for each cylinder of a jet fuel. Electromagnetic valve of a precise control of fuel injection and adjustment time. Pre-combustion jet is used to reduce noise.
A diesel engine emissions
The company in optimizing the engine combustion system to take the design principles not only to improve engine performance, but also to meet emission standards. Companies that installed on the fuel injector of the vehicle has reached the European IV standards. In fact they produced 65 percent of the diesel vehicles in line with the European IV standards.
In order to continue to meet and exceed the current emission standards for diesel engines for large companies to improve the top five, including internal combustion, fuel quality, oxidation catalytic converter, nitrogen oxides (NOx) emissions control device (or post-processing) and diesel particulate trap - (DPF).
?The focus should be on optimizing the internal combustion engine design, using various ways to reduce emissions in order to achieve satisfactory results. As more and more strict emissions regulations, and must therefore focus on how to control INOx and particulate (PM). In order to reduce the emissions V1OTDI engine, engine fitted with a pneumatic control exhaust gas recirculation (EGR) valve and EGR radiator. Oxidation catalytic converters installed in close to the location from the engine, the greatest extent possible not to clean up the emissions control. Two-slip road exhaust system has two catalytic converters: a pre-ceramic oval converters, installed in close to the location from the engine, another three oval into the engine to fit in at the bottom.
At present, V1OTDI Ouchuan with engine emission standards, the public company in Frankfurt auto show that they began to lV do not meet European standards of motor vehicles (about 5 O%) are fitted with particulate trap DPF, to meet the European IV. Last year, the Passat car at the bottom with a particulate trap system, which is the shell of steel materials, filter of a silicon carbide materials, with intake and exhaust channel. Inlet channel to collect carbon deposition, only emissions through porous ceramic wall into the exhaust channel. Filter in the filter process, to gather up the carbon deposition in the 500 íŠ at Shaojin. To be able to lower the temperature in the case under the conditions of combustion particles and reduce Huifen, add an iron diesel additives.
Bosch developed by the particulate trap, the material is sintered metal, and ceramic materials used now different. This new structure of the particulate deposition is very uniform, filter to filter again, the process is very simple. They also conducted two other studies, is a fuel additive, and the other is coated with catalytic converters, the two methods should be used to filter the exhaust filter again.
Second, common-rail diesel engine system
1. Bosch promote particulate trap system at the same time, they are still to all of the diesel engine car manufacturers to provide common-rail fuel system, to the three-cylinder Smart, 6-cylinder Audi and BMW, Audi and Mercedes-Benz eight-cylinder diesel cars matching .
Bosch started production in May last year, third-generation common-rail system, the electromagnetic injector for the implementation of the piezoelectric crystal has been replaced by the piezoelectric crystal from hundreds of very small crystal modules, the jet fuel Transform second time only 0.1 percent over the electromagnetic injector transform almost cut by half time. The third-and second-generation common-rail fuel injection system of pressure, are 1600 bar.
However, third-generation product, it's blasting process integrity and maintain stability, second-generation products than any of the injection process is complete, the old injection system limit each injection process, each jet fuel injection process up to five to seven times. The results show that third-generation common-rail system will reduce the emission of 15% ~ 2 O%, while the engine power increase by 5% to 7%.
The integration of the piezoelectric injector, or the piezoelectric actuator together with the nozzle valve installed in the first-injector, the fuel injection system to improve speed. As high-speed injection conversion, each an independent fuel injection process they reduce the interval between the time, so that more flexible control jet engines produce more power. The researchers are also trying to reduce the fuel injector in the moving parts, the nozzle needle on the activities of components from four reduced to one.
2, Germany-Erfu company's IV line with European standards of common rail systems, the fuel injector voltage battery voltage control, this is a very simple and low cost of electronic control devices. Delphi Corporation has begun to develop in line with European emission standards of a new generation of V common-rail system (expected by the end of 2004 or early 2005 on the market), and also study the new piezoelectric injection system, in order to make heavy-duty vehicles to meet the EU V And the new U.S. emissions regulations. And the current piezoelectric common-rail systems, Delphi hopes to produce a new generation of piezoelectric injection system of emissions should be reduced 2 5% ~ 3O%. Piezoelectric injector technology to ensure that injection system in each cycle and high-precision fuel injection seven times over.
3, Japan Electrical Company in 1995 developed the first high-pressure common rail diesel system, the company will be 1 800bar injection pressure for a new generation of common rail systems installed in the Mazda MPV and Mazda 6 sedan, the new Generation common-rail system, including: for pumps, with a common rail high pressure sensors, electromagnetic injector and by the driver of an electronic fuel injection devices and electronic engine controls a combination of control components, since the system started in 2002 Daou has IV standards.
Used for fuel pumps to the pressure, through the pipeline for fuel delivered to the common rail, and then use the electromagnetic injector to spray its combustion chamber. Fuel pump for pressure from the electromagnetic valve control, fuel pressure and engine speed and load to match the best value.
Denso Corporation is now used in a fuel injector for each jet fuel, when asked interval is 0.4 S, a five-stroke combustion of the fuel injection action. In order to meet the requirements of different users, Denso Corporation has developed a software, used to compensate the injector when the fuel injector deviation. System itself with a 2 1 D decoder. Each injector has its own value bias, when the engine control system to read every deviation value, the deviation will immediately add value.
And the development of other common-rail fuel system manufacturer, Denso company also is developing piezoelectric common-rail system, the use of piezoelectric technology has each injector will shorten the time interval of the 0.1 S, while also improving the speed injection The.
4, Siemens will piezoelectric common-rail system has been put on the market several years, was first installed in the Peugeot 307 car. The company said third-generation piezoelectric common-rail injection system (PCR3) will throw in mass production. PCR3 the core components is a new type of fuel injection, significantly reduced the size of the piezoelectric actuator directly into valve shaft, so that the jet pressure system from the second-generation common-rail injection system of the 1600 ba r pressure to 1800 bar. Siemens AG said third-generation common-rail injection system of the 2000 bar pressure to achieve the goal can be achieved, so that V meet EU standards.
New nozzle so that the structure of the injector needle control very quickly in a short period of time emitting a large number of high-pressure fuel, but not because of a hydraulic system caused by the impact of the unnecessary side effects. Therefore, the engine can be designed to have five independent injector of the structure, weight of less than 1 mg of fuel can be injected into the cylinder.
In piezoelectric actuator between the nozzle design and installation of a hydraulic compensation, which the piezoelectric actuator below the pressure delivered to servo valve, this can not only make up for the processing system at the minimum tolerance, but also because of compensation Temperature changes in the length of the injector and the system itself Wear The resulting changes. Controller connected with the engine, combustion engine knock sensor monitoring process, the situation on the jet to adjust, so that each work cycle will advance the process of calculating good, the same amount of fuel injected into the cylinder, so the value of emissions Remain stable.
World production of diesel engine parts on a few large manufacturers are active in development and production of low-emission engines, with direct injection, common-rail fuel, and other emerging technologies, diesel cars will have a lot of the market.