The invention discloses a multi-way valve, a crane hydraulic system and a crane. The multi-way valve comprises a telescopic unit, a variable amplitude unit and a winch unit. Each unit comprises a reversing valve, a pressure compensator, an electric proportional pilot valve and an overflow valve; the control end of the hydraulic control reversing valve is connected with a working port of the reversing valve, an inlet of the hydraulic control reversing valve is connected with an LS oil way of the pressure compensator, and an outlet of the hydraulic control reversing valve is connected with an oil return port through an overflow valve. The winch unit comprises a main winch and an auxiliary winch, and the main winch and the auxiliary winch share an overflow valve through a shuttle valve. According to the invention, the pressure of each oil outlet of the multi-way valve is used as a feedback condition to determine which overflow valve on a feedback oil way of a hydraulic system works according to innovation from a bottom-layer principle, so that the effect of limiting the pressure of a load feedback oil way is achieved. Under the overflow working condition, the upper vehicle reduces the displacement of the oil pump by limiting the pressure of the oil pump feedback oil way, so that the problem that a large amount of oil flows to the oil tank through the overflow valve is avoided, the energy-saving performance of the hydraulic system is improved, and meanwhile, the hydraulic system has the advantage of good composite action performance.
本发明公开一种多路阀、起重机液压系统及起重机,多路阀包括:伸缩联、变幅联和卷扬联;各联包括换向阀、压力补偿器、电比例先导阀及溢流阀;液控换向阀的控制端连接换向阀的工作口,液控换向阀的进口连接压力补偿器的LS油路,液控换向阀的出口通过溢流阀连接回油口;卷扬联包括主卷扬和副卷扬,主卷扬和副卷扬通过梭阀共用溢流阀。本发明从底层原理创新,把多路阀各出油口的压力作为反馈条件,来决定液压系统反馈油路上的哪个溢流阀起作用,从而起到限定负载反馈油路压力的作用。在溢流工况时,上车通过限制油泵反馈油路的压力来降低油泵排量,从而避免大量油液通过溢流阀流到油箱的问题,提升液压系统的节能性的同时具有复合动作性能好的优点。
Multi-way valve, crane hydraulic system and crane
一种多路阀、起重机液压系统及起重机
2025-02-18
Patent
Electronic Resource
Chinese