Micro-dynamic oil-returning electric control oil sprayer with hydraulic feedback

Abstract

The invention aims at providing a micro-dynamic oil-returning electric control oil sprayer with hydraulic feedback. The micro-dynamic oil-returning electric control oil sprayer comprises an oil sprayer head, an oil sprayer body, a flow limiting valve assembly, a solenoid valve assembly, a needle valve limiting sleeve, a nozzle and a needle valve body. A pressure accumulation cavity is formed in the oil sprayer body and is communicated with a main oil inlet and the flow limiting valve assembly, so that the stability of an oil spraying process of each cylinder is guaranteed under the condition that the oil spraying amount is great. The flow limiting valve assembly is arranged below the pressure accumulation cavity and the continuous movement of abnormal oil spraying is stopped. The solenoid valve assembly is machined at the bottom of the oil sprayer body and a valve rod is driven by an electromagnetic force to move, and an annular throttling belt and an oil inlet throttling hole on the tapered surface of a balance valve rod are matched with a hydraulic feedback oil path, so that a variable oil spraying rule that an oil spraying speed becomes rapid from slow is realized; and the seating response of a needle valve is accelerated. A solenoid valve adopts a two-position and three-way valve form so that the dynamic oil returning amount in an oil spraying process is greatly reduced. The inner part of the oil sprayer has no static pressure difference and the characteristic that the oil sprayer has no static leakage is guaranteed; and the hydraulic efficiency of the system is improved.

Description

technical field [0001] The invention relates to an engine fuel injection device. Background technique [0002] At present, the high-speed solenoid valve injector used has the advantages of fast system response, high control precision, flexible control strategy and reliable working performance. However, in view of the gradual improvement of emission regulations, there are a lot of improvements and upgrades in this electronically controlled fuel injector: First, in order to ensure the normal injection process of the fuel injector, the diameter of the oil outlet orifice must be larger than that of the oil inlet. Orifice diameter, and to further improve the response characteristics of the needle valve seat, it is necessary to increase the diameter of the oil inlet orifice, but this will increase the dynamic oil return volume and cause energy loss. Conversely, if the oil outlet orifice diameter is reduced in order to reduce the dynamic oil return volume, the speed of pressure bu...

AI Technical Summary

Problems solved by technology

However, in view of the gradual improvement of emission regulations, there are a lot of improvements and upgrades in this electronically controlled fuel injector: First, in order to ensure the normal injection process of the fuel injector, the diameter of the oil outlet orifice must be larger than that of the oil inlet. If you want to further improve the response characteristics of the needle valve seat, you need to increase the diameter of the oil inlet orifice, but this will increase the dynamic oil return and cause energy loss

Conversely, if the diameter of the oil outlet orifice is reduced in order to reduce the dynamic oil return, the speed of pressure building in the control chamber will be slowed down, resulting in a delay in the seat of the needle valve

Secondly, there is static leakage on the axial sealing surface of the control plunger coupling and the needle valve coupling in the injector, which reduces the hydraulic efficiency of the system and limits the further increase of the injector pressure

In addition, when the fuel injector injects a large amount of fuel, the oil pressure in the high-pressure common rail will fluctuate violently, which reduces the consistency of the fuel injection process of each cylinder

Images