Bypass-type electronically-controlled oil injector with carved grooves

Abstract

The invention aims at providing a bypass-type electronically-controlled oil injector with carved grooves. The bypass-type electronically-controlled oil injector comprises an oil injector head, an oil injector body, a flow-limiting valve assembly, an electromagnetic valve assembly, a locking nut, a needle valve assembly, a nozzle, a needle valve seat and other components. A pressure accumulation cavity is formed in the oil injector body, and communicates with a main oil inlet hole and the flow-limiting valve assembly, so that a stable oil injection process of each cylinder in the case of large-pulse-width oil injection can be ensured. The electromagnetic valve assembly and the needle valve assembly are sequentially arranged below the flow-limiting valve assembly. The electromagnetic valve assembly and the needle valve assembly are connected together through the locking nut. A control slide block is arranged in a control cavity and contacts with a middle block, thereby playing the roles of slowing down an oil injection speed in the initial stage of injection and accelerating the seating response of a needle valve. The carved grooves with micron-level depths are formed in the surface of a needle valve body, and capable of effectively improving the stability of cavitation flow, thereby lowering the cavitation erosion degree of the oil injector. The needle valve assembly part achieves internal hydraulic pressure balance and has no static pressure difference, thereby realizing the function of no static leakage of the oil injector.

Description

technical field [0001] The invention relates to a fuel injection device, in particular to a high-pressure common rail fuel injection device. Background technique [0002] As the requirements for fuel economy and emission characteristics of the engine are getting higher and higher, the emission limitation mainly lies in two aspects of nitrogen oxides and particulate matter. In order to reduce the emission of nitrogen oxides, it is required to control the opening of the needle valve at the beginning of fuel injection, so that there is a low fuel injection rate and a gently rising fuel injection rate during the ignition delay period, which is beneficial to ensure the fuel injection process and Consistency in the shape of the fuel injection rate; at the end of the fuel injection, the closing speed of the needle valve is required to be fast, which is beneficial to the rapid pressure build-up of the system. That is to say, it can realize the characteristic curve of fuel injection...

AI Technical Summary

Problems solved by technology

As the work of the injector increases gradually and the flow rate increases, the degree of cavitation and cavitation in the injector increases significantly, and the reliability of the injector decreases.

In addition, the presence of the control plunger causes a static pressure difference in the injectors, resulting in static leakage of fuel

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