A novel variable pressure differential load sensing system for quantitative pump and its control method

Abstract

The invention discloses a novel variable pressure differential load sensing system of a quantitative pump, comprising a load sensing valve, a safety protection valve, a pressure compensator, a first reversing valve, a differential pressure control valve, a load sensing valve, a safety protection valve and a pressure compensation valve The oil inlet end of the compensator is connected to the oil inlet, the load sensitive valve is respectively connected with the differential pressure control mechanism and the safety protection valve, the pressure compensator is connected with the first reversing valve, and the differential pressure control valve includes a damping hole and a differential pressure control mechanism. and the second reversing valve, the differential pressure control mechanism is connected with the second reversing valve, and a damping hole is arranged between the differential pressure control mechanism and the second reversing valve; The pressure difference of the valve realizes that the flow output is related to the actual demand of the system. Through the variable pressure difference, the overflow loss of the system in the standby state is reduced, thereby improving the energy saving of the system.

Description

technical field [0001] The invention belongs to the technical field of energy saving and environmental protection of cranes, and in particular relates to a novel variable pressure differential load sensing system of a quantitative pump and a control method thereof. Background technique [0002] The load-sensing system of the quantitative pump has good energy-saving characteristics and stability, and has been widely used in the hydraulic system of cranes. At present, the method of constant pressure difference control is used, and the pressure difference ΔP of the system is set through the load-sensing valve. When the system is working , so that the pump outlet pressure is always higher than the load pressure by ΔP, so as to achieve adaptive matching between the system pressure and the load pressure. [0003] In the prior art, the commonly used method is the method of constant pressure difference control, and the control principle is: [0004] (1) In the standby state, the hy...

AI Technical Summary

Problems solved by technology

[0008] The main problem of the above method is: in order to compensate the pressure loss along the pipeline caused by the maximum flow rate, the load sensing valve ΔP needs to be set at a higher pressure, that is, the constant pressure difference is generally set at a higher value, which makes the state (non-working state), the quantitative pump system has a large overflow loss, resulting in a large amount of heat dissipation

Images