Research On Key Technology Of Large Liameter Solenoid Pilot Operated Valve For Electro-hydraulic Control Hydraulic Support

Solenoid pilot operated valve is a core device of the hydraulic support electro-hydraulic control system. Due to the special environment of coal mine, the current hydraulic support electro-hydraulic control system needs to meet essential safety requirements of GB3836.4, and the maximum working current of the electromagnet is limited to 200 m A, which limits the electromagnetic thrust. At present, the valve core opening is around 0.1mm, which can be easily blocked by the coal dust and particulate contamination in emulsion. This phenomenon may lead to the electro-hydraulic control system failure and affects the safety production of coal mine. In this paper, the opening of valve core is appropriately enlarged to improve the anti-blockage capability of solenoid pilot operated valve fundamentally, on the basis of existing structure. The core components and flow field are optimized to enhance the response characteristics and opening-closing characteristics of solenoid pilot operated valve. The experiment bench is established to verify the performance of solenoid pilot operated valve. The main research contents of this paper are as follows:(1) The structure composition of solenoid pilot operated valve and principle of electro-hydraulic control hydraulic support valve group was analyzed. Through the force analysis of the valve parts, the flow equation and the mathematical model of solenoid pilot operated valve were established.(2) According to the analysis of the reasons for blocking solenoid pilot operated valve, the valve core opening increased to 0.3mm and the reset spring is optimized based on a support vector machine. The dynamic characteristic of the optimized valve was simulated by the use of Simulink, and the change rules of valve core displacement, flow and hydrodynamic characteristics were explored in the open and reset process.(3) The flow field characteristics of solenoid pilot operated valve with different inlet flow rates, outlet pressure and valve core openings were simulated by the use of Fluent. The simulation results indicated that the flux is smaller, the fluid flow is more stable, the pressure is less loss, and the life of the valve is longer. When the opening of valve core is enlarged to 0.3mm, the anti-blockage capability of valve can be improved and the flow field performance of valve core can be perfected.(4) The experiment bench of solenoid pilot operated valve was built, and the opening-closing performance, response time and flow-pressure difference characteristic of the optimized valve were tested. The results showed that the solenoid pilot operated valve possesses better anti-clogging ability, and its opening-closing performance, response time and flow-pressure difference characteristic can meet the design requirements.