Magneto-rheological pilot safety valve of hydraulic support based on magnetic control material and its application

Abstract

The invention relates to a magneto-rheological pilot-operated safety valve for a hydraulic support based on a magnetic control material and its application, comprising a valve body, a valve core, a return spring and a pilot valve; The valve is placed in the pilot valve cavity opened in the valve body; the pilot valve includes a magnetically controlled shape memory alloy, an electromagnet, a push rod, a piston, a magneto-rheological fluid control coil, and a pilot valve core arranged in sequence from left to right; A plurality of magnetic control material control coils are provided, and the magnetic control shape memory alloy penetrates through the electromagnet and is connected to a push rod, and the push rod is connected to the piston, and the magnetorheological fluid is located between the piston and the pilot valve core. The invention uses magnetorheological fluid to control the action of the pilot valve core, relies on the extremely short response time of the magnetorheological fluid, and cancels the return spring structure in the pilot valve core of the traditional large-flow safety valve, and uses a magnetically controlled shape memory alloy as the The reset device of the pilot valve spool shortens the response time.

Description

technical field [0001] The invention relates to a magnetically controlled material-based magnetorheological pilot safety valve for a hydraulic support and an application thereof, belonging to the technical field of valves. Background technique [0002] With the depletion of underground shallow coal resources, it is an inevitable trend for coal mine production to develop to a large mining depth, and the problems that follow are the sudden increase in the support pressure of the coal mine working face and frequent rock burst phenomena. In order to deal with the above problems, most of the current coal mine hydraulic supports adopt the measures of installing large flow safety valves. However, in actual application, it was found that the large flow safety valve could not respond in time when the rock burst occurred, causing damage to the structure of the hydraulic support, and even causing casualties. Through on-site investigation and theoretical analysis, the researchers found...

AI Technical Summary

Problems solved by technology

However, in actual application, it was found that the large-flow safety valve could not respond in time when the rock burst occurred, causing damage to the hydraulic support structure, and even causing casualties

Through on-site investigation and theoretical analysis, the researchers found that the reason why the large-flow safety valve fails to act when the rock burst occurs is that the time when the rock burst acts on the hydraulic support column is extremely short, and the impact of the rock burst After being mounted on the bracket, it takes a certain amount of time for the oil to be transferred to the spool of the high-flow safety valve through the upper and lower chambers of the column, and it takes a certain amount of time for the spool of the high-flow safety valve to overcome the action of the spring.

The sum of these two periods exceeds the action time of the rock burst, resulting in the impact energy not being unloaded in time

The huge impact energy is released through the deformation of the hydraulic support, which causes structural damage, deformation and instability of the hydraulic support, resulting in coal mine safety accidents

Chinese patent documents CN107725083A and CN103953369A provide a hydraulic support safety valve reset method using nitrogen to reset the valve core. Using gas as an elastic material to reset the valve core has a faster response speed than traditional safety valves using spring resets, but compressed gas is Elastomers also have elastic modulus, and there is still room for improvement in response speed

The safety valve adopts the electric control part to control the magneto-controlled shape memory and the magneto-rheological fluid to solve the problems of the traditional safety valve in the hydraulic shock transmission time and spring response time are too long

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