Direct-injection engine
With the increasing shortage of oil resources, the people of the car’s fuel economy increasingly high demand for this, a new type of gasoline engine combustion came into being, that lean burn engine technology, the ideal way to achieve lean combustion is direct injection (FSI) stratified injection, that is, gasoline direct injection (GDI). Direct injection engine is gasoline in the cylinder injection, the injector installed in the combustion chamber, direct injection gasoline combustion chamber in the cylinder, the air entering the combustion chamber through the intake valve and fuel mixture is ignited mixture into acting, which forms and direct injection diesel engine is similar, therefore, cylinder injection gasoline engine is ported to the form of diesel gasoline on a major initiative.
Direct injection engine air-fuel ratio to 40:1, with fuel savings, reduced emissions and improved dynamic performance, reduce engine vibration, improve the accuracy of fuel injection engine is more durable, etc., all the car manufacturers have launched their own The direct injection engine, such as Volkswagen’s FSI (Fuel Stratified Injection), GM’s SIDI (spark ignition direct injection), Toyota’s D-4S, BMW’s HPI (high pressure direct injection), Mitsubishi company GDI (gasoline direct injection), Porsche’s DFI (direct fuel injection) and so on.
Direct injection, also known as FSI, FSI (Fuel Stratified Injection) Fuel Stratified Injection technology represents a conventional gasoline engine development. Conventional gasoline engine is collected through computer-related cam position and the engine operating conditions to control the fuel injectors to spray fuel into the intake manifold. However, due to the combustion chamber nozzle from a certain distance, the mixing of gasoline with air by the air intake valve switches and the impact of large and small oil particles adsorbed on the pipe wall, so I hope to direct the fuel injectors sprayed into the cylinder.
FSI is Volkswagen Group developed to improve the way the traditional gasoline engine oil shortage developed in the cylinder direct injection technology and advanced direct injection gasoline engine similar to that of diesel engine oil technology, through a piston pump to provide the required The above 100bar pressure in the cylinder gasoline supplied to the solenoid injectors. And then by computer-controlled jet fuel in the most appropriate time directly into the combustion chamber, the control accuracy close to millisecond, the key is to consider the installation of injectors, the cylinder must be in the upper left to the certain space. Since the cylinder at the top has arranged a very environmentally friendly spark plugs and a number of public 1.4TSI engine valve, it is very compact, so it is arranged near the intake valve side. As the jet to join the cause of design and manufacturing requirements are quite high, if the layout is unreasonable, mainly the manufacture of precision can lead to stiffness of the leak even more harm than good enough. In addition FSI engine fuel quality requirements are relatively high, the current state of the domestic oil FSI engine may be difficult to achieve the requirements, so part of the assembly of imported golf FSI engine appeared acclimatized.
In addition, FSI technology uses two different oiling patterns, that is layered and uniform oiling oiling patterns. Low or medium speed engine operation mode when stratified oiling. At this point the throttle is partially open air from the intake manifold into the cylinder hit the top of the piston, the piston at the top made into a special shape to the formation of expectations in the spark plug near the vortex. When towards the end of the compression process, a small amount of fuel emitted by the jet, the formation of combustible gases. This hierarchical approach can be fully grease the engine of the economy to improve, because speed is low, the load is small, except around the spark plug needs to form a high concentration of gas mixture, the combustion chamber of the other places with higher levels of only the mixture of air can, and FSI is very close to the ideal state. When the throttle fully open, the engine at high speed, a lot of air into the cylinder to form a strong high-speed vortex mixing with gasoline. Thereby contributing to fuel combustion, improved engine power output. Computer constantly change according to the working conditions of the engine fuel injection mode, always the most appropriate way of oil. Full use of fuel not only improve fuel efficiency and engine output and improved emissions.