Novel constant delivery pump variable differential pressure load sensitive system and control method thereof

Abstract

The invention discloses a novel constant delivery pump variable differential pressure load sensitive system which comprises a load sensitive valve, a safety protection valve, a pressure compensator, afirst reversing valve and a differential pressure control valve, the oil inlet ends of the load sensitive valve, the safety protection valve and the pressure compensator are connected to an oil inlet, and the load sensitive valve is connected with a differential pressure control mechanism and the safety protection valve. The pressure compensator is connected with the first reversing valve, the differential pressure control valve comprises a damping hole, the differential pressure control mechanism and a second reversing valve, the differential pressure control mechanism is connected with thesecond reversing valve, and the damping hole is formed between the differential pressure control mechanism and the second reversing valve. The pressure difference of the load sensitive valve in the constant delivery pump load system is changed through the pressure difference control valve, flow output is related to actual requirements of the system, overflow loss of the system in a standby state is reduced through variable pressure difference, and therefore energy saving performance of the system is improved.

Description

technical field [0001] The invention belongs to the technical field of crane energy saving and environmental protection, and in particular relates to a novel quantitative pump variable pressure difference load sensitive system and a control method thereof. Background technique [0002] Quantitative pump load-sensing system has good energy-saving characteristics and stability, and has been widely used in crane hydraulic systems; at present, the method of constant pressure difference control is used to set the pressure difference ΔP of the system through the load-sensing valve. When the system is working , which can make the pump outlet pressure always higher than the load pressure by ΔP, so as to realize the 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 hydraulic oil output by th...

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