Diesel engine injector ‌ is a vital component in the diesel engine fuel supply system. Its main function is to atomize the fuel into fine oil droplets and spray it into a specific part of the combustion chamber. The injector meets the requirements of different types of combustion chambers for atomization characteristics according to the characteristics of the diesel engine mixture formation.

Types and structures of injectors

Injectors are mainly divided into open injectors and closed injectors. The open injector has a simple structure but poor atomization and is rarely used; while the closed injector is widely used in various diesel engines. The closed injector is usually composed of the injector body, the pressure regulating device and the injector nozzle. The injector nozzle is composed of the needle valve and the needle valve body. The two are precisely matched, and the gap is only 0.002~0.004mm‌1,2.

Classification of injectors

According to the different structural forms of the injector nozzle, the closed injector can be divided into the hole injector and the shaft needle injector. The hole-type fuel injector is suitable for direct injection combustion chambers. Its structure includes needle valves, needle valve bodies, push rods, pressure regulating springs and other components. The needle valve is pushed by high-pressure diesel to open the spray hole to achieve fine atomization of the fuel ‌2,3. The shaft needle fuel injector is mostly used in indirect injection systems such as pre-combustion chambers and swirl chambers ‌2.

Working principle and application scenarios

The hole-type fuel injector pushes the needle valve to open the spray hole through high-pressure diesel to achieve fine atomization of the fuel. Its porous and small-diameter structure enables it to achieve fine atomization of the fuel under high pressure, meeting the efficient fuel distribution requirements of the direct injection system. The hole-type fuel injector is widely used in diesel engines with direct injection combustion chambers ‌2,3.

Maintenance

In order to ensure the normal operation of the fuel injector and extend its service life, regular maintenance is essential. Key measures include regular replacement of fuel filters, inspection and adjustment of injection pressure, etc. In addition, the design of the fuel injector takes into account high-temperature and wear-resistant materials to ensure that it can still maintain good performance under high-intensity working conditions ‌4.