Tappet rod type high pressure co-rail electric-controlled oil ejector

Abstract

The invention provides a tappet type high pressure common rail injector, consisting of an injector body, a high-speed electromagnet, a tappet, a pin valve component, a two-position two-way switch valve and a middle cushion block component, wherein, a central lathy pylome of the injector body is a cascade circular hole, the tappet is arranged inside a small-diameter circular hole of the injector body, the high-speed electromagnet comprises a static iron core, a movable iron core and an offsetting spring. The tappet type high pressure common rail injector has simple structure, greatly reduces the leakage of the high pressure fuel, is easy to establish the high pressure inside the injector body, and realizes the high pressure or the supervoltage fuel injection, thereby satisfying the requirements of much more stringent emission regulations of a diesel engine.

Description

technical field [0001] The invention is a tappet type high-pressure common-rail electronically controlled fuel injector, which is applied to a high-pressure common-rail electronically controlled fuel injection system of a diesel engine. Background technique [0002] The CR series high-pressure common rail electronic control fuel injection system of German Bosch company is currently the most advanced diesel engine electronic control fuel injection system, including: electronic control fuel injector, high pressure common rail, high pressure oil pump, pressure regulating valve, pressure limiting valve, Current limiter, various sensors and electronic control unit, etc. The high-pressure common rail electronically controlled fuel injector is its core and most critical components, including high-speed solenoid valve components: moving iron core, excitation coil, return spring, static iron core, oil return pipe, large nut, return spring, moving iron core Guide rod, large adjustmen...

AI Technical Summary

Problems solved by technology

Since these parts are sliding fit, there must be a gap. The gap should not be too small, otherwise reliable reciprocating motion cannot be guaranteed, and if it is too large, the fuel leakage must be serious, and high pressure cannot be established and high-pressure injection cannot be realized.

Obviously this is an insurmountable contradiction, and with the continuous upgrading of diesel engine emission regulations, the emission regulations are becoming increasingly strict, and the diesel engine must further increase the fuel injection pressure, which makes the problem of gap sealing in these parts more prominent. In fact, due to these parts It is very difficult to further increase the injection pressure of the high-pressure common rail injector with this structure

In addition, the radial clearance between the potassium plane of the valve sleeve shoulder and the hollow plane of the injector body leaks, and the axial clearance between the minimum outer circle of the valve sleeve and the inner hole of the injector body leaks

Although these two places are static seals, as the injection pressure further increases, it is also difficult to ensure a reliable seal

Similarly, if the leakage of these parts cannot be effectively controlled, the ultra-high pressure injection in the high-pressure common rail injector is also impossible to achieve

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