A fuel injector for high pressure common rail fuel injection system

Abstract

A fuel injector for a high-pressure common rail electronically controlled fuel injection system disclosed by the invention comprises a fuel injector body part, a fuel injection nozzle part and a solenoid valve part. The control valve assembly is composed of a control valve seat and a control valve core, and the cone angle of the upper conical section of the control valve core is smaller than the cone angle of the axial sealing tapered hole on the control valve seat, thus forming a balanced valve structure, which can Greatly improve the response speed of electronically controlled fuel injectors. The present invention sets a center needle valve socket in the orifice plate, which is filled with high-pressure fuel oil, which can greatly reduce the dynamic leakage of fuel injector parts. The contact surfaces among the fuel injector assembly, the orifice plate, the control valve assembly and the fuel injector body of the present invention are all precision surfaces. Significantly improve the sealing and reliability of the system.

Description

technical field [0001] The invention relates to a fuel injector, in particular to a high-pressure fuel injector applied to a high-pressure common rail fuel injection system. Background technique [0002] Electronically controlled high-pressure common rail fuel injection system, as the best choice for diesel engines to meet China III, China IV or higher emission standards, consists of high pressure fuel supply pumps, high pressure fuel rails, electronically controlled fuel injectors, ECU and sensors. In this system, the electronically controlled fuel injector is the most critical and complex part. Its function is to control the opening and closing of the solenoid valve according to the control signal sent by the ECU, and inject the fuel in the high-pressure fuel rail at an optimal Injection Timing, Injection Quantity, and Injection Rate Inject fuel into the engine combustion chamber. A typical high-pressure common rail injector is composed of an injector, a control piston, a...

AI Technical Summary

Problems solved by technology

However, with the increase of injection pressure, it is difficult to guarantee the reliability of the ball valve under the existing technology level and mechanical processing equipment of domestic fuel system manufacturers, so this ball valve structure is not suitable for injectors with 2000bar and above

It is also pointed out in the literature that for the improvement of the needle valve couple, various inventions mainly start from reducing the dimensional tolerance accuracy and wear of the parts, so as to reduce the leakage of the couple and achieve the effect of precise control, but it will greatly increase the manufacturing difficulty and process cost.

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