Two-way-oil-inlet resonance bypass type electronic-control fuel injector

Abstract

The invention aims at providing a two-way-oil-inlet resonance bypass type electronic-control fuel injector comprising a fuel injector head, a fuel injector body, a flow-limiting valve assembly, an electromagnetic valve assembly, a needle valve assembly and a spray nozzle. The flow-limiting valve assembly is located in a pressure storage cavity, and it is ensured that under the condition of the large fuel injection quantity, fuel injection processes of all cylinders are stable. A resonance through hole and a resonance throttling hole are machined in the bottom of the flow-limiting valve assembly, and fluctuation of fuel passing through the flow-limiting valve assembly is reduced according to the wave superposition principle. The electromagnetic valve assembly and the needle valve assembly are arranged on the lower portion. A two-position three-way valve form is adopted for an electromagnetic valve so that the dynamic oil return amount can be decreased. A control slide block is arranged in a control cavity and makes contact with a middle block so as to play a role in decreasing the fuel injection speed at the initial stage of injection and accelerating the needle valve seating response. The two-way-oil-inlet manner is adopted for the control cavity, and therefore the pressure buildup speed is further increased, and the rapid response characteristic of the fuel injector is achieved. No static pressure differences exist in the fuel injector, and the fuel injector is free of static leakage.

Description

technical field [0001] The invention relates to an engine fuel injection device. Background technique [0002] The high-speed solenoid valve type fuel injector realizes complex fuel injection rules with the help of the controller, which has the advantages of fast response, high control precision, flexible control strategy and reliable working performance. However, with the gradual increase of the fuel injection pressure in the current fuel injector, the performance of the fuel injector is also tested in various aspects: the fuel injector has static leakage when it is not injecting fuel; the form of two-position two-way valve The dynamic oil return volume is large, which affects the fuel utilization rate; at the beginning of the injection, the fuel injection rate is too high, resulting in an increase in the emission of nitrogen oxides, and after the injection, the control chamber enters the oil in a single way, and the pressure build-up speed is slow, so that the fuel cut-off...

AI Technical Summary

Problems solved by technology

However, with the gradual increase of the fuel injection pressure in the current fuel injector, the performance of the fuel injector is also tested in various aspects: the fuel injector has static leakage when it is not injecting fuel; the form of two-position two-way valve The dynamic oil return volume is large, which affects the fuel utilization rate; at the beginning of the injection, the fuel injection rate is too high, resulting in an increase in the emission of nitrogen oxides, and after the injection, the control chamber enters the oil in a single way, and the pressure build-up speed is slow, so that the fuel cut-off is not rapid , resulting in the rise of particle emissions; needle valve movement and fuel injection will stimulate water shock pressure waves, resulting in fuel pressure changes in each volume chamber; when a large amount of fuel is injected, the fuel injection process of the fuel injector may affect the fluctuation of the common rail pressure , making the stability and uniformity of the fuel injection process of each cylinder decrease

Images