Load-sensitive rotation buffer valve and crane rotation hydraulic system

Abstract

The invention discloses a load-sensitive rotation buffer valve and a crane rotation hydraulic system. A middle path of a rotation reversing valve is sequentially connected with a guide oil port of a three-way pressure compensation valve and an oil inlet of a constant flow valve through an LS feedback oil path, an oil inlet of the three-way pressure compensation valve is communicated with an oil inlet of a valve body, an oil outlet of the three-way pressure compensation valve is communicated with an oil returning opening of the valve body, an oil outlet of the constant flow valve is divided into two paths, one path is directly connected with the oil returning opening of the valve body, the other path is communicated with an oil inlet of a first one-way valve and an oil inlet of a second one-way valve at the same time, a speed adjusting valve is formed by the three-way pressure compensation valve and the rotation reversing valve, flow adjustment of a work oil port A and a work oil port B is achieved, flow is output proportionally, influences of the load are avoided, in the whole operation process, action is stable, fast and slow action is avoided, stable opening is achieved, during stopping, pressure impact is small, and a crane cannot rotate and swing.

Description

technical field [0001] The invention relates to the field of engineering machinery, in particular to a load-sensitive rotary buffer valve and a crane rotary hydraulic system. Background technique [0002] Medium and large-tonnage truck cranes have long booms and large load capacity. When the whole machine is slewing, the slewing inertia is large, resulting in poor slewing performance (large space-time travel when starting, and large slewing swing when stopping). If a closed system is used, Although the operating performance is superior, the cost is relatively high. [0003] Chinese patent 01142605.5 discloses a rotary buffer valve, the principle of which is figure 1 As shown, including the main valve body, there are oil inlet P, oil outlet T and the working oil port A / B connected to the hydraulic motor on the main valve body, and the oil inlet P and oil outlet T of the main valve body The ports are respectively connected to the oil inlet and the oil outlet of the steering ...

AI Technical Summary

Problems solved by technology

The steering reversing valve 1 of this patent adopts the principle of bypass shunt flow. During the operation process, the fluctuation of the pressure at the load end will directly affect the flow of A / B port, that is, the output flow is unstable, which will cause the rotation to be fast and slow, such as When the position of the operating handle remains unchanged, when the load increases, the hydraulic oil pumped out of the pump goes to the A / B port of the load end to decrease, and more hydraulic oil returns to the oil tank through the operation of the reversing valve 1, so that the rotation speed becomes slower. Similarly, when the load decreases, the slewing speed becomes faster. Large-tonnage cranes adopt this slewing technology. Due to the large inertial load, the space-time travel is large when starting, and the turntable swings greatly when stopping, which is a potential danger to both people and machines.

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