Multi-mode piezoelectric normally closed electronically controlled unit pump

Abstract

The invention aims to provide a multi-mode piezoelectric normally closed electronic control unit pump. The pump comprises a double-jumper cam, a roller plunger, a normally closed piezoelectric fuel oil control valve, a fuel oil path reverse valve and double oil outlet valves, wherein the normally closed piezoelectric fuel oil control valve is arranged on the upper side of the plunger and comprises an electromagnetic valve, a control valve rod, an oil drainage conical valve and an oil drainage conical valve spring; the fuel oil path reverse valve is arranged on the upper side of the normally closed piezoelectric fuel oil control valve and comprises a piezoelectric crystal, a front reverse valve rod, a reverse valve, a rear reverse valve rod and a fuel oil path partition block. The working efficiency of the electronic control unit pump can be effectively improved, the engine efficiency is improved, the requirements on oil supply frequency, oil supply pressure and oil supply quantity under different working conditions and different loads of an engine are met, the engine economy and dynamic property are improved, and harmful emission is effectively reduced.

Description

technical field [0001] The invention relates to a fuel injection device, in particular to an engine fuel injection device. Background technique [0002] With the development and progress of human society, the development of modern engines has to face the dual pressures of energy crisis and environmental pollution, and the engine emission standards are constantly improving, which makes the development of engines must be in the direction of energy saving and emission reduction. The use of electronic control to realize the control of the engine fuel injection system has become the development trend of the engine, and the electronically controlled unit pump technology is an important technical means. The electronically controlled unit pump is a time-controlled fuel injection system that meets engine emission regulations and economic requirements. It has the characteristics of high fuel injection pressure and flexible and adjustable fuel injection timing. The development of piez...

AI Technical Summary

Problems solved by technology

However, the traditional electronically controlled single pump has the following disadvantages: first, the high-speed switching solenoid valve only has two working states of on and off, and cannot complete multi-mode control; second, the response speed of the solenoid valve is limited, and the control accuracy and working stability are not high. ; Third, the unit pump has low working efficiency, and the camshaft can only complete the fuel supply function to one injector after one revolution; Fourth, if the cam profile is simply changed to a double peach cam, the fuel supplied by the camshaft one revolution The fuel injection quantity of more than one fuel injector will reduce the efficiency of the engine fuel system; fifth, the traditional electronically controlled unit pump can only complete the control function of a single control valve, which is difficult to meet the needs of the engine under different working conditions. Requirements for the fuel injection process; Sixth, when the solenoid valve fails to be powered on, the oil drain circuit will always be open, and the normally open valve will not be able to complete the function of controlling fuel flow; Seventh, if the solenoid valve is stuck in In the closed state, the oil pressure in the valve will continue to rise, causing adverse effects on the normally open valve and the injector, resulting in damage to other hydraulic devices such as the injector

In short, the traditional electronically controlled unit pump has low working efficiency and poor safety, and cannot meet the stability of the engine, and does not have the ability to respond to failures in a timely manner.

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