Multi-flow control valve, chassis supporting leg hydraulic control system and crane

Abstract

The invention relates to a multi-flow control valve, a chassis supporting leg hydraulic control system and a crane. The multi-flow control valve comprises a valve body and at least one switching value control valve, the valve body comprises a valve body oil inlet and at least two valve body work oil openings corresponding to loads of different flow demands, an oil inlet of the at least one switching value control valve is communicated with the valve body oil inlet, a work oil opening of the at least one switching value control valve is communicated with the at least two valve body work oil openings of the valve body, at least two work oil channels corresponding to the loads of the different flow demands are formed, and a throttling opening with the drift diameter corresponding to the flow demands is formed in each work oil channel. Compared with an exiting control mode of a proportional directional valve, due to the fact that the flow is mainly determined by the throttling openings of the valve body, the requirement for the precision of the switching value control valve is low, cost is low, the sensitiveness of the switching value control valve to oil pollution is low, the pollution resisting capacity is high, and therefore higher reliability is achieved.

Description

technical field [0001] The invention relates to the field of engineering machinery, in particular to a multi-flow control valve, a chassis outrigger hydraulic control system and a crane. Background technique [0002] In the outrigger hydraulic system of the crane chassis, there are many kinds of hydraulic cylinders for the actuators. Some hydraulic cylinders with similar parameters can adopt a flow control, and some hydraulic cylinders have different flow requirements from other hydraulic cylinders, such as the pin cylinder with small flow requirements. Etc., if only adopting the switching value control of single oil pump, there will be problems. [0003] The current solution is to use a variable variable pump to connect the proportional directional valve, and use the current supplied to the proportional directional valve to adjust the flow into the load. Such as figure 1 As shown, it is a hydraulic schematic diagram of an existing solution for hydraulic control of crane c...

AI Technical Summary

Problems solved by technology

[0005] There are many problems in this current solution: firstly, the proportional directional control valve a4 has high cost, poor reliability, and is sensitive to oil pollution; secondly, the load sensitive control hydraulic system is highly sensitive to load changes, The adjustment response to load changes is fast, but in practical applications, adjusting the output power too frequently may affect the working life of the machine; finally, the valve diameter control is subject to the influence of proportional reversing valve hysteresis and repeatability, etc. some imprecision

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