Quick-closing and slow-opening type hydraulic priority valve

Abstract

The invention discloses a quick-closing and slow-opening type hydraulic priority valve, and belongs to the field of hydraulic energy conservation. The hydraulic priority valve comprises a pilot valve, a main valve, a speed regulating valve and a one-way valve, wherein the pilot valve is arranged on the main valve; the speed regulating valve is integrated in a valve element of the main valve; the one-way valve and the main valve share one valve body; the valve body is provided with a port A connected to an oil supply inlet of a main pump and a port D connected to a common load loop at the main valve; the valve body is provided with a port B connected to an oil supply inlet of an auxiliary pump and a port C connected to a steering and shifting loop at the one-way valve; the pilot valve is provided with a port F connected to an oil tank; a feedback cavity E arranged in the pilot valve is always communicated with an oil cavity A of the main valve; and a containing cavity G of the pilot valve is always communicated with a containing cavity H of the main valve. According to the hydraulic priority valve, the speed regulating valve is integrated in the valve element of the main valve, the basic functions that the main pump and the auxiliary pump preferentially supply oil to a steering loop, a gear shifting operation loop and the like, and the steering speed and the gear shifting speed are stable and reliable can be achieved, and the problem that a valve element of a traditional hydraulic priority has certain lag in dynamic response is effectively solved.

Description

technical field [0001] The invention belongs to the field of hydraulic energy saving, in particular to a hydraulic priority valve. Background technique [0002] Hydraulic priority valves are often used in construction machinery, metallurgy, automobile and other industries. Taking construction machinery as an example, the hydraulic steering system and shift control system in construction machinery currently use load sensing systems, and the hydraulic priority valve is the key component of the system. The function of the hydraulic priority valve is to control the order in which the pump group supplies oil to different oil circuits. From the perspective of functional requirements, it can be regarded as a three-way fixed differential flow valve. In construction machinery, the hydraulic priority valve can preferentially distribute the inlet flow to the steering oil circuit and the control oil circuit according to the steering speed and the needs of shifting manipulation. During...

AI Technical Summary

Problems solved by technology

The reason is that most traditional hydraulic priority valves only control the opening and closing of the main valve through a throttle port. Although the basic functions can also be realized, the speed of valve opening and closing cannot be adjusted.

On the one hand, when the vehicle’s steering circuit and gear shift control circuit are in urgent need of oil, this design may cause a delay in the closing speed of the main valve, which slows down the mechanical response speed; on the other hand, when the steering circuit and gear shift control circuit use oil When the demand is met and the priority valve distributes excess oil to other working circuits, this design may cause the main valve to open faster, resulting in large pressure fluctuations before and after the steering gear and shifter, which in turn affects the overall working performance of the machine

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