| The explosion-proof solenoid directional control valve is indispensable and one of the most biggest dosage component in coal mine hydraulic system, its capability directly has influence on the capability of hydraulic system of the whole mining equipments.With the fast development of coal industry, coal bed exploitation technic in China has reached international leading level, which gains fruitful and efficient effects. For the need of mine underground equipments, there has to be the corresponding explosion-proof solenoid directional control valve to match with it. When the explosion-proof solenoid directional control valve is used, it is expected to have both manual function when power cut or faults occur. On the basic of analysis and study on a great deal congeneric valves of inside and outside country, a sort of credible,both manual and electromechanical and little cubage explosion-proof solenoid directional control valve is need to be real time manufactured.The explosion-proof bidirectional designed in this paper can replace the former voluminous ones, which saves space for limited fixing station.The flexible and credible bidirectional control mode enhances the operational and change-over capability of the valve. At the same time, the wet type electromagnetic iron is explosion-proof, which improves the security of operation under the coal well.The main research content is listed as below:(1)According to the parameters of the change-over valve, the choosing of components, the devising of structure are realized.(2)The three-dimensional geometrical model of flow field within spool valve is built by pre-processor software Gambit of Fluent.The built model is partitioned to meshes by Gambit. When the meshes are made, the entrance and exit of oil flow line are partitioned by rough meshes, while the meshes of small throttle and ones in mutation location of flow section are partitioned by micromesh ones.(3)When the spool valve element is steady the flow field inside the spool valve is visualizing analysis. The whole spool valve model is separated into the metering-in spool valve and metering-out spool valve to research and analyze. Comparing the path line, velocity distribution, turbulent kinetic energy and pressure distribution the metering-in spool valve and metering-out spool valve, it offers the theory foundation for designing spool valve.(4) The different diametrical pole of spool valve models are simulated and analyzed, on the situation of contented flux, The diameter of pole for spool valve should choose bigger value, it offers the theory foundation for designing diameter of pole for spool valve.(5)A new method which compensates for flow force by opening slant-hole in the valve sleeve is put forward in the paper. Fluent software is used to simulate and compare flow state before and after the valve to open slant-hole and analyze change of the axial velocity. The effect of compensation for flow force is analyzed from the view of the momentum change. At the same time, by the analysis of the pressure distribution on the spool wall, the cause, size and direction of the flow force production are analyzed from another point of view. It is pointed out that the flow forces is generated mainly due to the change of velocity in the valve port, which caused the variation of the pressure distribution on the spool wall. Thus, an additional axial force is generated. That is steady-state fluid force. |
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