Pressure-compensated valve, load-sensitive hydraulic system and crane applying same

Abstract

The invention discloses a pressure-compensated valve, comprising a valve body and a valve core arranged inside the valve body, wherein the valve core slides in the valve body so as to communicate or disconnect an oil inlet and an oil outlet of the valve body; four relatively closed cavities are formed between the valve core and the valve body, a first control oil inlet, a second control oil inlet, a first control oil outlet and a second control oil outlet, which are communicated with each cavity, are arranged in the valve body; and oil in the cavities communicated with the first control oil inlet and the first control oil outlet acts on the valve core to form a trend of sliding towards one side, and oil in the cavities communicated with the second control oil inlet and the second control oil outlet acts on the valve core to form a trend of sliding towards the other side. On the basis, the invention further provides a load-sensitive hydraulic system and a crane applying the pressure-compensated valve so as to adjust the flow of executive components and ensure the proportional flow distribution of each executive component during flow saturation.

Description

technical field [0001] The invention relates to engineering machinery technology, in particular to a pressure compensation valve, a load sensitive hydraulic system and a crane using the valve. Background technique [0002] Load sensing technology is widely used in various construction machinery, the main reason is that it has good energy saving, hydraulic pump can provide corresponding flow according to the system demand, the flow required by the system is not affected by the load pressure, and when the main valve is in the middle When it is in position, low voltage overflow can be realized, thereby reducing the power loss of the system. [0003] At present, with the acceleration of the pace of social development, the requirements for construction machinery are not limited to basic working performance such as energy saving, safety and reliability. How to improve operating efficiency has become the key point of optimal design, especially, the design of compound movements is ...

AI Technical Summary

Problems solved by technology

[0005] However, for the traditional load sensing system (LS system) that realizes compound action, there are certain defects in the use process, for example, when the system needs to realize the simultaneous action of multiple actuators, if the maximum flow supplied by the hydraulic pump is less If the required total traffic is exceeded, the load-sensitive system will lose its load-sensitive function and cannot realize the on-demand distribution of saturated traffic

Although the prior art has subsequently developed a LUDV hydraulic system and a load-sensing system integrating AVR functions in order to overcome the above-mentioned defects; however, the above-mentioned solutions also have their own shortcomings: the former components are very expensive, which greatly increases the manufacturing cost of the crane; the latter The flow distribution of the crane is not proportional, so it cannot fully meet some special operating requirements of the crane hydraulic system, such as energy saving, micro-movement and compound action of the crane hydraulic system.

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