A micro-injection electronically controlled fuel injector with a pressure-holding structure

Abstract

The invention relates to a micro-injection electronically-controlled fuel injector with a pressure-maintaining structure. According to the micro-injection electronically-controlled fuel injector, an upper fuel cavity as well as a main fuel inlet channel, a main fuel return channel, a fuel inlet channel and a fuel return channel which communicate with the upper fuel cavity are formed in the upper body of the fuel injector; the lower body of the fuel injector is connected to the lower end of the upper body of the fuel injector through a fuel injector fastening nut, a lower fuel cavity is formed in the lower body of the fuel injector, and the lower fuel cavity communicates with the main fuel return channel; a nozzle member is connected to the lower end of the lower body of the fuel injector through a nozzle fastening nut and communicates with the lower fuel cavity, and further communicates with a main fuel channel penetrating through the lower body of the fuel injector; and an electromagnetic valve is connected to the left side of the upper part of the upper body of the fuel injector through an electromagnetic valve fastening nut, one end part of a control valve element of the electromagnetic valve stretches in the upper fuel cavity, and the other end part of the control valve element is abutted against an electromagnetic valve return spring arranged at the central part of an electromagnet. According to the micro-injection electronically-controlled fuel injector disclosed by the invention, a fuel inlet process and a fuel return process can be mutually independent, so that the influence of the mutual interference of fuel flowing in the fuel inlet process and the fuel return process on a fuel injection process is avoided; and the opening speed of a needle valve can be increased, so that the injection characteristic of a micro-injection fuel system is improved.

Description

technical field [0001] The invention relates to a dual-fuel engine, in particular to a micro-jet electronically controlled fuel injector with a pressure-holding structure, in particular to a micro-jet fuel injector for a dual-fuel engine. Background technique [0002] In order to alleviate the energy crisis and reduce environmental pollution, dual-fuel engines that can realize diesel / natural gas switching, low emissions, and low pollution have attracted more and more attention. [0003] Micro-injection electronically controlled fuel injector is a kind of fuel injector applied to dual-fuel engines. Its function is to inject a small amount of fuel into the cylinder as pilot fuel in the gas mode of the dual fuel engine. Compared with the main fuel injector, the amount of pilot fuel injected by this injector is only 1%~5% of the fuel amount in pure diesel mode, so it is called a micro-spray injector. The spray quality of the pilot fuel is a reliable guarantee for the stable ig...

AI Technical Summary

Problems solved by technology

The natural gas intake port and the main injector occupy most of the space on the cylinder head, so the installation space of the micro-injection electronically controlled injector is very small, resulting in relatively slender oil passages inside the micro-injection electronically controlled injector

The slender oil passage will reduce the cross-sectional area of ​​the fuel flow, increase the fuel flow resistance and pressure loss at the same time, and then make the opening / closing time of the needle valve longer and the fuel injection duration longer

In addition, during the fuel injection process of the electronically controlled fuel injector, the inlet / return oil passages are connected to each other, and the extension of the fuel injection duration will lead to an increase in the oil return. The fuel pressure build-up time increases, and the opening speed of the needle valve slows down

The above shortcomings all affect the injection characteristics of the micro-injection fuel system

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