Research On The Moving-coil Reducing Valve Operating Characteristics Of HMT Clutch

Proportional reducing valve is the key control element of the HMT Clutch hydraulic system,its performance is very important to hydraulic system.Nowadays the valve is driven by proportional solenoid.The reducing valve is configured with movingcoil motor in this paper.In order to increase the thrust density of motor,to reduce the influence of temperature on thrust and to deal with the hysteresis,the research is conducted in this paper on the characteristic of magnetic field and thrust characteristic,the temperature characteristic and hysteresis characteristic.These researches have great significance on performance of moving-coil valve and control quality of HMT clutch hydraulic system.On the basis of the existing analytical model of axis moving coil magnetic field,the research is conducted in this paper to analyze the influence between structure parameters and air gap magnetic field,thrust and stroke.A design procedure is come up with in this paper to increase thrust density.The dynamic performance of movingcoil motor is also be analyzed.In order to deal with the motor thrust drop under higher temperature of magnet,the thermal resistance model is built and analyze the temperature characteristic under different current condition.The effect of motor thrust and magnet temperature is researched.And the current compensation under temperature feedback and no feedback condition is conducted to improve thrust control performance.To depress the effect of moving-coil thrust hysteresis,the Preisach model is introduced and model parameters are identified.The inverse model is built and the effect of temperature on thrust is considered.With the combination of current compensation and hyteresis inverse model,the negative effects of hysteresis on thrust control is reduced.The experiments of moving-coil reducing valve and proportional valve are conducted.And it is proved that moving-coil valve has an advantage in dynamic characteristic.It means moving-coil valve is helpful to improving the quality of clutch hydraulic control system.