Piezoelectric control pressure accumulation and stabilization oil sprayer

Abstract

The invention provides a piezoelectric control pressure accumulation and stabilization oil sprayer which comprises an oil sprayer head, an oil sprayer body, a flow limiting component, a needle valve reset spring, a nozzle, a needle valve, a tightening cap, a piezoelectric control component and a locking sleeve. The flow limiting component structure is adopted, the situation that the economical efficiency of fuel oil is reduced due to the fact that the oil sprayer sprays oil abnormally and continuously can be effectively avoided, and work reliability of the oil sprayer is guaranteed. Pressure fluctuation caused in the fuel oil spraying process can be reduced through a pressure accumulation cavity in the oil sprayer body, and oil spraying stability can be controlled precisely. When the oil sprayer is used for a common-rail fuel oil system, the structural size of a common-rail pipe can be reduced, and therefore the strength requirement for common-rail pipe materials is lowered, the service life of the oil sprayer can be prolonged, and the space utilization rate of the oil sprayer can be improved. The needle valve is directly driven by a piezoelectric stack in the movement process, and is high in response speed, the control freedom degree is large, the oil spraying rule is flexible and variable, the dynamic property and economical efficiency of a diesel engine are effectively improved, and the diesel engine can meet the stricter emission regulation.

Description

technical field [0001] The invention relates to a fuel injector, specifically a diesel fuel injector. Background technique [0002] The traditional mechanically controlled fuel injector is mainly composed of injector body, nozzle, needle valve coupling, etc. It has the advantages of simple structure and high working reliability, but its fuel injection timing, fuel injection pressure and fuel injection rate are limited Due to the restriction of the cam shape of the high-pressure fuel supply pump, there are inflexible fuel injection characteristics, slow response, and poor control accuracy of the fuel injection quantity. With the increasingly stringent emission regulations, it is difficult to further improve the economy and emission performance of the engine. Also can not satisfy present market to the requirement of engine. [0003] Compared with the mechanically controlled injector, the electromagnetically controlled injector used in the electronically controlled fuel inject...

AI Technical Summary

Problems solved by technology

Although the electromagnetically controlled fuel injector has improved the emission performance of the diesel engine, there are still some shortcomings: because there is a control piston above the needle valve, it has a certain restrictive effect on further improving the response speed of the fuel injector; at the same time, due to the The turbulent flow will be intensified during the fuel injection and fuel cut-off of the injector, causing severe pressure fluctuations in the fuel injection system, causing large fluctuations in the fuel injection pressure and fuel injection rate, and increasing the precise control of the fuel injection volume. Moreover, the structure of the electromagnetically controlled fuel injector is complicated. Due to the inductance of the solenoid valve coil, there is a certain lag time in its response, which leads to the limitation of further increasing the number of fuel injections and the repeatability of fuel injection needs to be improved. These The shortcomings make the existing electromagnetic control injector unable to meet higher requirements such as flexible control of injection rate

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