Accumulator Piezo-Solenoid Control Injector with Control Chamber Slider

Abstract

The object of the present invention is to provide a pressure accumulator piezoelectric-electromagnetic control fuel injector with a control chamber slider, which includes a fuel injector body, a pressure boost control valve part, a fuel injection control valve part, and a needle valve part. The pressure accumulator chamber of the present invention can reduce the pressure fluctuation caused during the fuel injection process, which is beneficial to the precise control of the fuel injection stability; the action process of the needle valve is directly driven by the piezoelectric stack, the needle valve has a fast response speed and a large degree of control freedom , The fuel injection schedule is flexible and changeable, effectively improving the power and fuel economy of the diesel engine, enabling the diesel engine to meet more stringent emission regulations. At the same time, the design of the oil inlet orifice of the control chamber and the oil inlet passage of the control chamber slider will make the fuel pressure in the control chamber rise rapidly, thereby greatly increasing the seating speed of the needle valve and realizing wedge-shaped injection. At the same time, the oil inlet passage of the slider in the control chamber can make the slider in the control chamber reach hydraulic balance quickly.

Description

technical field [0001] The invention relates to a diesel engine, in particular to a diesel engine fuel system. Background technique [0002] The traditional mechanically controlled fuel injector has the advantages of high reliability and simple structure. However, because its fuel injection characteristics such as fuel injection timing, fuel injection pressure and fuel injection rate are restricted by the cam profile of the high-pressure fuel supply pump, it has disadvantages such as inflexible fuel injection characteristics, slow response, and poor control accuracy of fuel injection volume. . With the increasingly stringent emission regulations, it is difficult to further improve the economy and emission performance of the engine, nor can it meet the requirements of the current market for the engine. [0003] Compared with the mechanically controlled injector, the electromagnetically controlled injector used in the electronically controlled fuel injection system of a dies...

AI Technical Summary

Problems solved by technology

Although the electromagnetic control injector has improved the emission performance of the diesel engine, there are still some shortcomings: the injector usually adopts the form of single-way oil inlet, and the response speed of the needle valve seat is slow, and due to the balance of the diameter of the inlet and outlet holes relationship, it is difficult to further improve the response characteristics; the dynamic oil return in the form of a two-position two-way valve is large, which affects fuel utilization; the axial gap between the needle valve and the control plunger causes static leakage in the injector Fuel problem; due to the inductance of the solenoid valve coil, there is a certain lag time in its response, which leads to further increase in the number of fuel injections is limited, and the repeatability of fuel injection needs to be improved; in the state of large fuel injection, the fuel injection of each cylinder Process uniformity and stability decline, etc.

Images