A hydraulic system and control method for electric proportional control multi-position valve

Abstract

The invention discloses a hydraulic system for electric proportional control of a multi-working position valve and a control method thereof. The system comprises: a first main pump, a second main pump, a pilot hydraulic control handle group, a stick oil cylinder, a main controller, an electric The proportional valve, and the valve core with multiple working positions inside, the signal output end of the main controller is jointly controlled with the retracted pilot conducting proportional valve, and the pilot ports at both ends of the valve core are respectively connected with the pilot hydraulic control handle group, the retracted pilot conducting The proportional valve joint control realizes the regulation of the working position of the spool. The main controller in the hydraulic control system of the present invention can judge the working condition of the actuator, and then can choose to operate and control the hydraulic system in different working conditions of heavy-load working position or light-load working; The oil return flow of the rod cavity is adapted to different working conditions through the area ratio of the oil return check valve and the regeneration check valve, so as to realize the fine adjustment of the back pressure ratio of the actuator, and finally realize the back pressure control of the actuator under different loads.

Description

technical field [0001] The invention belongs to the technical field of hydraulic pressure, and in particular relates to a hydraulic system and a control method of an electric proportional control multi-position valve. Background technique [0002] In construction machinery, when the thrust direction of the hydraulic cylinder is opposite to the direction of the load (in most cases), the load is called a resistance load; As a result, the load on the hydraulic cylinder is in the same direction as the thrust of the hydraulic cylinder, and the load is called a tensile load at this time. Under the condition of tension load, the cavity on the oil supply side of the oil cylinder is very easy to cause the hydraulic components to suck due to insufficient flow, so the oil return back pressure is usually set higher under the tension load At low engine speed, the minimum flow obtained by the hydraulic actuator is not taken as a standard), in order to avoid damage to the hydraulic actuat...

AI Technical Summary

Problems solved by technology

Setting a higher oil return back pressure of the actuator will result in a large oil return back pressure when the actuator is single-acting or when the engine speed is high, resulting in energy loss, especially under the resistance load condition of the actuator, the oil return back pressure is large Causes a large loss of machine energy consumption and low work efficiency

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