In modern fuel injection systems, fuel injectors play a vital role. It directly affects engine performance, fuel economy and emissions. According to different classification standards, there are many types of fuel injectors.
According to the injection method, fuel injectors are mainly divided into continuous injection and intermittent injection. Continuous injection means that the fuel injector continuously injects fuel throughout the engine working cycle, and the amount of fuel injection depends on the needle valve opening time of the injector and the fuel pressure. This method has a simple structure, but because the fuel cannot be accurately distributed according to the actual needs of the engine, it is rarely used in practical applications.
Intermittent injection can be divided into simultaneous injection, group injection and sequential injection. Simultaneous injection means that all injectors inject fuel at the same time. This method is simple to control, but the fuel distribution uniformity is poor. Group injection is to divide the injectors into several groups, and the injectors in the same group inject fuel at the same time. Compared with simultaneous injection, it can improve the fuel distribution uniformity to a certain extent.
Sequential injection is to inject fuel in time before the start of the intake stroke of each cylinder according to the working order of each cylinder of the engine. It can accurately control the injection amount and injection time according to the actual needs of each cylinder, and has good fuel distribution uniformity. It is currently the most widely used injection method.
According to the injection pressure of the injector, there are low-pressure injectors and high-pressure injectors. Some early small engines mostly used low-pressure injectors, and their injection pressure was relatively low. With the development of engine technology and the improvement of performance requirements, high-pressure injectors have gradually become the mainstream. High injection pressure can make the fuel atomization effect better, thereby improving combustion efficiency and engine performance.
In addition, according to the injector drive mode, it can also be divided into voltage drive and current drive. Different types of fuel injectors have their own characteristics in performance and application range, meeting the needs of different engines and driving the continuous development of related industries such as automobiles.