Multiway electro-hydraulic control valve adopting oil return differential pressure as pilot oil source

Abstract

The invention relates to a multiway electro-hydraulic control valve adopting oil return differential pressure as a pilot oil source. The multiway electro-hydraulic control valve comprises an oil inflow valve group, an oil return pressure adjusting valve group, and multiple electro-hydraulic directional control valve groups arranged between the oil inflow valve group and the oil return pressure adjusting valve group. Common oil inflow channels, middle unloading channels and double-way oil return channels are arranged in valve bodies of the oil inflow valve group, the electro-hydraulic directional control valve groups and the oil return pressure adjusting valve group. The common oil inflow channels are communicated with the common oil return channels in parallel respectively. The middle unloading channels are of a series oil way structure. Pilot oil cylinders are arranged in end covers of the electro-hydraulic directional control valve groups. One end of a directional main valve element of each electro-hydraulic directional control valve group is connected with the corresponding pilot oil cylinder in a coaxially matched mode. Electromagnetic pilot valves are integrated on the electro-hydraulic directional control valve groups. Pilot pressure adjusting valves are arranged in the oil return channels of the oil return pressure adjusting valve group. 2-3 Mpa constant-value differential pressure is formed at the front ends and the rear ends of overflow ports of the pilot pressure adjusting valves. The safety guarantee requirements for remote control over hydraulic machines and safety guarantee for equipment or staff in an emergency can be met, and configuration of pipelines and the oil source is reduced.

Description

technical field [0001] The invention belongs to hydraulic machinery, in particular to a multi-channel electro-hydraulic control valve using oil return pressure difference as a pilot oil source. Background technique [0002] At present, the control methods adopted by multi-channel electro-hydraulic directional valves at home and abroad are: the hydraulic control control directional control method of externally controlling the pilot oil source; external solenoid valves are connected at one or both ends of the main spool of the valve body to control the directional control. The pilot oil source is provided externally; the pressure oil is diverted from the oil inlet channel and sent to the solenoid pilot valves of each reversing valve group after decompression to be used as a pilot control oil source; a small amount of pressure oil is diverted from the oil inlet channel of each valve group , After decompression, it enters the pilot solenoid valve at the rear end of the valve gro...

AI Technical Summary

Problems solved by technology

[0004] (1) The use of an externally controlled pilot oil source brings about a significant increase in the cost of the configuration and control of the hydraulic oil source, and each valve group needs to be connected to an external oil inlet and return pipeline

[0005] (2) The structure of the solenoid valve connected to the end of the valve body is adopted, the volume of the valve group increases a lot, the installation and maintenance are inconvenient, and a pilot oil source needs to be configured, and each group of valve groups needs to be connected with an external oil inlet and return pipeline

[0006] (3) Using the method of diverting the pilot oil in the oil inlet will lose part of the working flow, resulting in power loss, and the structure of the oil inlet diverter valve group will be complicated due to the internal diversion and pressure reducing valve core assembly, and the failure rate will increase

Since the shunt flow is affected by the pressure change of the main oil circuit and the oil temperature, it will cause the mutual interference of the pressure and flow between the main oil circuit and the shunt oil circuit, which will affect the stability

[0007] (4) Adopting the method of providing the pilot oil source through diversion and decompression inside the valve group, it is necessary to add a diversion and decompression function in each valve group, resulting in a complex structure of each valve group, and a significant increase in the failure rate of multiple combinations. Reduced reliability and substantially increased cost

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