Displacement adjusting method for positive-flow hydraulic pump of excavator

Abstract

The invention discloses a displacement adjusting method for a positive-flow hydraulic pump of an excavator. A throttle opening is arranged on an oil return passage in a multiple directional control valve in a hydraulic system, and a plurality of pilot valves are installed outside a variable pump; largest pilot pressure is selected through a shuttle valve group to control the displacement of the hydraulic pump, and a displacement value of the hydraulic pump is controlled according to opening degrees of a way of valves with largest pilot pressure; an electric control unit of the hydraulic pump is reserved on one of main valves, and the pilot pressure of the main valves is converted into electrical signals through a pressure sensor; main hydraulic pump outlet pressure is detected to calculate another displacement value of the main pump according to a curve, the displacement of the main pump is adjusted according to the two values; and the pressure sensor, a tilt angle sensor and a displacement sensor are arranged at corresponding positions of the excavator. The displacement adjusting method for the positive-flow hydraulic pump of the excavator has the advantages that the output flow of the hydraulic pump is in accordance with the operation of operators, the response time is short, the flow fluctuation is small, the operability is good, and the working efficiency can be improved.

Description

technical field [0001] The invention relates to the field of hydraulic technology, in particular to a method for adjusting the displacement of a positive flow excavator hydraulic pump. Background technique [0002] The hydraulic system has the advantages of large power, good adjustability of working pressure and flow, heat can be brought back to the oil tank, etc. However, there are multiple energy conversions in hydraulic transmission, and the hydraulic oil tank causes potential environmental pollution and oil loss. Therefore, hydraulic technology must improve the performance of hydraulic transmission and control in order to meet the needs of sustainable development and energy saving. Mechanical transmission competitiveness. At present, mainstream excavators still use multi-way valve as the main control valve. The main power loss of this type of system includes throttling loss, overflow loss during the starting and braking process of the slewing mechanism, potential energy...

AI Technical Summary

Problems solved by technology

However, there are multiple energy conversions in hydraulic transmission, and the hydraulic oil tank causes potential environmental pollution and oil loss. Therefore, hydraulic technology must improve the performance of hydraulic transmission and control in order to meet the needs of sustainable development and energy saving. Mechanical transmission competitiveness

At present, mainstream excavators still use multi-way valve as the main control valve. The main power loss of this type of system includes throttling loss, overflow loss during the starting and braking process of the slewing mechanism, potential energy loss and throttling during the boom lowering process. Losses and losses caused by poor matching of engine and hydraulic system power

With the development of hydraulic energy-saving technology, the hydraulic system of excavators has developed into various control methods such as negative flow control, positive flow control and load sensitive control. Limited and highly affected by load, these will lead to low product share