Fuel injection electronic unit injector of a diesel engine

Abstract

The invention discloses a fuel injection electronic unit injector of a diesel engine, which comprises a plunger and barrel assembly, a plunger spring, a plunger spring base, a plunger cushion block, an elastic collar, a rocker cushion block, a fuel atomizer nut, an electromagnetic valve and a fuel atomizer, wherein the fuel atomizer and the electromagnetic valve are stacked in the electromagnetic valve nut from bottom to top, and are tightly connected with the plunger and barrel assembly through threads in advance; a pump body and a control valve base are provided with auxiliary pressure fuel passages (including pressure fuel passages and bypass fuel passages) communicated with a fuel pressure cavity and a main pressure fuel passage leading to the fuel atomizer; and one to three fuel passages and bypass fuel passages are arranged in pairs. The invention can realize the accurate and flexible control of optimum fuel injection quantity, optimum fuel injection time and fuel injection pressure, improve combustion in the engine cylinder, increase fuel taking speed and quantity, and reduce fuel sucking resistance and friction when a spool moves and the reset load of the plunger spring so that the harmful effulent of the engine is reduced and the economical, dynamic and intelligent properties of the engine are improved.

Description

technical field [0001] The invention relates to a pump nozzle for a diesel engine, in particular to a fuel injection electronically controlled pump nozzle for a medium-power diesel engine. Background technique [0002] Existing diesel engine fuel injection devices are mechanical synthetic pumps or electronically controlled unit pumps. The mechanical synthetic pump is composed of fuel injection pressure regulating mechanism, fuel injection quantity regulating mechanism, fuel injection time regulating mechanism and injection mechanism. The fuel injector of the electronically controlled unit pump has an independent oil pump, which is simplified in structure, but still retains the high-pressure pipeline. These two types of injection devices have low control precision, poor flexibility, and narrow control range. The road is long, there is pressure loss, the pressure of the fuel injection pump is usually lower than 1500bar, and pressure fluctuations such as residual pressure and...

AI Technical Summary

Problems solved by technology

These two injection devices have low control accuracy, poor flexibility, and narrow control range. The road is long, there is pressure loss, the pressure of the fuel injection pump is usually lower than 1500bar, and pressure fluctuations such as residual pressure and reflected waves will cause abnormal injection; there are various straight grooves and inclined grooves on the plunger, which increase leakage and reduce strength and stiffness , the pressure at the pump end is difficult to increase above 1300bar

Due to these shortcomings, mechanical synthetic pumps cannot meet Euro III and above emission standards

The electronically controlled unit pump also limits the increase in fuel injection pressure and the reduction of emission standards

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