Needle valve coupling of common rail oil injector

Abstract

The invention discloses a needle valve coupling of a common rail oil injector, and belongs to the technical field of oil injection systems. The needle valve coupling of the common rail oil injector comprises a needle valve, a needle valve body and an elastic module, wherein the needle valve is located in the needle valve body, a pressure chamber is formed between the interior of the needle valve body and the bottom of the needle valve, a plurality of oil injection holes are formed in the bottom of the needle valve body, the oil injection holes are formed in the circumferential direction of the pressure chamber, the elastic module is arranged at the bottom of the needle valve, a plurality of oil outlet holes distributed in the circumferential direction are formed in the periphery of the elastic module, a high-pressure oil channel is formed in the needle valve, an outlet of the high-pressure oil channel communicates with the oil outlet holes, a ball valve is arranged between the elastic module and the outlet of the high-pressure oil channel, and the ball valve is controlled to be opened or closed through the pressure of fuel oil in the high-pressure oil channel. In the lifting process of the needle valve, dynamic compensation of the fuel oil injection flow can be realized, so that the oil injection amount in unit time can be improved, meanwhile, the cavitation phenomenon inside an oil nozzle is relieved, and the service life of the oil injector is prolonged while the working performance of the oil injector is improved.

Description

technical field [0001] The invention relates to the technical field of fuel injection systems, in particular to a needle valve couple of a common rail fuel injector. Background technique [0002] In the traditional high-pressure common rail injector, the needle valve coupling is the most critical structural component in the entire oil supply system. When high-pressure fuel flows into the fuel injector from the pressure chamber of the needle valve body, due to the sharp change in the cross-sectional area of ​​the fuel flow and the flow direction, the fuel pressure drops sharply, resulting in serious cavitation on the upper surface of the fuel injector, which will occur over time. Surface cavitation shortens the service life of the injector itself and seriously affects the injection characteristics, working stability and safety of the injector. As the injection pressure of the common rail system continues to increase, when the fuel flows through the cone surface of the needle...

AI Technical Summary

Problems solved by technology

Although the above method can reduce the flow loss to a certain extent, it is difficult to meet the actual needs of specific engineering applications, which limits the actual application scenarios

In addition, the generation of cavitation inside the fuel injector cannot be effectively suppressed, so the flow coefficient of the fuel injector cannot be improved to improve the injection performance of the fuel injector

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