Design And Research Of A Novel Electromagnetic Drive Mechanism For Hydraulic Valves

In the hydraulic system,when the hydraulic reversing valve action causes a sudden change in the liquid flow state,since the flowing liquid and the hydraulic control element have inertia,under the influence of the inertial force,the liquid pressure suddenly rises,resulting in a high pressure peak,this phenomenon is called hydraulic shock.The pressure peak generated by hydraulic shock is often 3 to 4 times higher than the normal working pressure,and often accompanied by a large vibration and noise,which brings hidden dangers to the normal operation of the hydraulic system.In recent years,with the development of hydraulic technology in the direction of high power,high pressure and high speed,more stringent requirements have been placed on the performance of hydraulic components.Therefore,it is of great significance to reduce the commutation impact of hydraulic components.This paper designs a new type of electromagnetic drive mechanism which is for hydraulic valve,which can reduce and regulate the hydraulic shock.The new electromagnetic drive mechanism mainly comprises a bistable permanent magnet mechanism and a magnetorheological fluid damper(MRD).The function of the bistable permanent magnet operating mechanism is to keep the valve in holding position or to converse;The function of the MRD is to change the yield strength of the MRF by controlling the magnitude of the current input to the coil during conversing,thereby outputting a controllable damping force to offset the hydraulic shock which is caused by the electromagnetic driving force of the bistable permanent magnet operating mechanism.Therefore,this mechanism has the advantages of high working stability,maximum hydraulic shock reduction,and continuous operation of the hydraulic system.The paper mainly includes the following parts:(1)Firstly,according to the working condition of the hydraulic valve,design the bistable permanent magnet operating mechanism,and the static and transient electromagnetic field simulation is performed in the Ansoft Maxwell software to verify whether the mechanism can meet the requirements.(2)Design the MRD according to the force situation when the bistable permanent magnet operating mechanism converses.It is proposed that the minimum damping force generated by the MRD can not hinder the normal commutation of the bistable permanent magnet mechanism,and the maximum damping force that the MRD can generate must be able to effectively reduce the bistable permanent magnet.Use the genetic algorithm to optimize the key structural parameters which affect the MRD performance: the effective length of the damping gap and the damping gap width are optimized under different viscous force conditions;then,according to the optimization result of the genetic algorithm,perform the electromagnetic field analysis in Maxwell software,get the corresponding magnetic field strength;according to the results of Maxwell simulation,establishes the damping force model of MRD in Simulink software,select the structure which best meets the design requirements according to the Simulink analysis.