Design And Experimental Study Of Magnetorheological (MR) Valve With Hybrid Supply Magnetic Source And Double Annular Channels

The rapid technological development of the world’s industries and the increasing popularity of automobiles have led to an increase in auto repair services.At present,most of the car lift systems used in auto repair centers are hydraulic lift systems,in which valves are important components in the hydraulic system to provide precise positions.Traditional hydraulic valves have problems such as difficult control and high friction and wear.Smart material magnetorheological fluid has the advantages of controllable rheological characteristics and fast response time,and magnetorheological valve based on magnetorheological fluid is one of the effective methods to solve the problems of traditional hydraulic valves.However,poor stability of ordinary magnetorheological fluid,low pressure drop performance,and long response time of ordinary magnetorheological valves are the main reasons that limit the application of magnetorheological valves.To solve the above problems,this paper proposes the method of microgel polymer coating carbonyl iron powder to prepare a new magnetorheological fluid,and design MR valve with hybrid supply magnetic source and double annular channels,and experimentally study its pressure drop performance and response time characteristics.The main work of this paper is as follows:(1)In order to meet the requirements of magnetorheological valve applications,a polymeric microgel coating method of carbonyl iron powder was proposed,and a new magnetorheological fluid with high stability was prepared by using the base-loaded liquid substitution method,and then the surface morphology,physical phase and magnetic properties of the coated particles were tested to study the coating effect;oxidation resistance,redispersibility and settling stability of the new magnetorheological fluid were tested to study its stability.The results showed that the HPM coated carbonyl iron powder was successful and the coated particles had good magnetic properties,and the stability of the prepared new magnetorheological fluid was good.(2)MR valve with hybrid supply magnetic source and double annular channels is proposed,the magnetic circuit calculation is carried out according to electromagnetic field theory,and the key structural dimensions of the magnetorheological valve are determined and calibrated.The structural model is established and pressure drop analysis is performed for different fluid flow channels.The hypothesis that the MR valve with hybrid supply magnetic source and double annular channels has three operating modes of two channels working separately and two channels working together is proposed,and the corresponding theoretical pressure drop calculation formula is obtained according to different operating modes.(3)MR valve with hybrid supply magnetic source and double annular channels performance test system is built,and LabVIEW is used for data acquisition to obtain the effects of current and load variations on the pressure drop performance and response time of the magnetorheological valve,and the experimental results are analyzed.The results show that the hypothesis of the proposed three operating modes of inner-loop channel working alone,outer-loop channel working alone,and dual-channel working together is valid.MR valve with hybrid supply magnetic source and double annular channels pressure drop increases with the increase of current;different loads have little effect on MR valve with hybrid supply magnetic source and double annular channels pressure drop at the same current.The change of current has a large effect on the rising response time and an insignificant effect on the falling response time;the load has a small effect on the response time characteristics of the magnetorheological valve.(4)In order to further verify the theoretical pressure drop formula proposed in the hypothesis,the magnetic field in the flow channel of the MR valve with hybrid supply magnetic source and double annular channels is simulated using the finite element magnetic field analysis method to study the influence of input current,damping gap and other parameters on the magnetic field of the MR valve with hybrid supply magnetic source and double annular channels.The results show that the simulated and experimental values of single channel operation basically match;when the inner and outer ring channels work together,the overall pressure drop of the valve is equal to the theoretical pressure drop equation of the single channel pressure drop to obtain a better fit between the simulated and experimental values.