Crane and multi-way valve hydraulic system thereof

Abstract

The invention discloses a multi-way valve hydraulic system which comprises a multi-way valve set connected with a performing mechanism, first and second oil pumps connected with the oil supply line of the valve set, and a flow distributing and converging device, wherein the flow distributing and converging device is arranged between the second oil pump and the oil supply line; when the difference between the oil supply pressure of the oil supply line and the load pressure of the hydraulic system is greater than a preset value, the flow distributing and converging device is in a first state, so that hydraulic oil output by the second oil pump flows back to an oil tank through the flow distributing and converging device; when the difference between the oil supply pressure of the oil supply line and the load pressure of the hydraulic system is smaller than the preset value, the flow distributing and converging device is in a second state, so that the hydraulic oil output by the second oil pump enters the oil supply line to be converged with hydraulic oil in the first oil pump. The hydraulic system is capable of outputting the hydraulic oil with the corresponding flow quantity according to the flow quantity required by the performing mechanism, so that the energy waste is avoided and the smoothness and the micro-motion property of the system are improved. The invention further discloses a crane to which the multi-way valve hydraulic system is applied.

Description

technical field [0001] The invention relates to the technical field of cranes, in particular to a crane and its multi-way valve hydraulic system. Background technique [0002] Cranes usually adopt a multi-valve hydraulic system, that is, multiple valve groups arranged in parallel are used to jointly control the action of the actuators. As users increase the efficiency of crane operations, hydraulic pumps are required to provide sufficient flow to meet system requirements. [0003] Please refer to figure 1 , figure 1 It is the hydraulic principle diagram of the multi-way valve hydraulic system of the crane in the prior art. [0004] Currently, if figure 1 As shown, most of the power components of the crane hydraulic system using the quantitative pump system use the first oil pump 1' and the second oil pump 2', and the pressure oil output by the two gear pumps is jointly supplied to the actuator after the oil supply circuit merges. . This double-pump oil supply method can...

AI Technical Summary

Problems solved by technology

[0006] First of all, since the hydraulic system always uses double pumps to supply oil, it will cause a lot of energy waste under certain working conditions

For example, when the actuator moves at a low speed, the required flow of the system is small. If the dual pumps are still used to supply oil, a large amount of excess flow generated will be overflowed and consumed in a large amount only in the form of heat

[0007] Secondly, because the hydraulic oil output by the two gear pumps is too large, the valve ports of the reversing valves of each valve group 5' are subjected to a large pressure shock when they are just opened, which directly affects the smoothness and fretting of the system

Images