Structural Design And Performance Analysis Of Rotary MR Damper For Automotive Scissors Seat Suspension

The semi-active control suspension of automobile seat is one of the common ways to reduce vibration of automobile seat,which can effectively improve the safety and comfort of passengers.However,the traditional automobile seat semi-active control suspension adopts a direct-acting MR damper,which has the disadvantages of large space occupation,high production cost and small adjustable range.In view of the above shortcomings,a rotary MR damper with T-shaped rotor was proposed and applied to the vibration reduction of automobile scissors seat.The structure design,magnetic circuit design and electromagnetic field simulation of the rotary MR damper were carried out;the damping torque test platform and damping force performance test platform were built,the torque performance test of the designed rotary MR damper was carried out,and the damping performance test of the shear seat suspension with the damper was carried out.The main contents of this paper are as follows:(1)A rotating MR damper with T-shaped rotor was proposed and designed.Through the reasonable use of magnetic isolation materials to guide the direction of magnetic field lines,so that it has four axial effective liquid flow channels and two radial effective liquid flow channels,so as to improve the utilization rate of magnetic field and have a higher adjustable range.According to Ohm’s law of magnetic circuit and Ampere’s loop theorem,the magnetic circuit was designed and calculated.According to the application situation,the size of each part was designed and the strength is checked.According to the selected constitutive model of MR fluid,the mathematical model of damping torque was deduced.(2)Using the finite element simulation software to simulate the electromagnetic field,the magnetic line of force of the rotary MR damper was analyzed,the variation law of the magnetic induction intensity at each effective flow channel and the average magnetic induction intensity were solved,and the theoretical value of the output damping torque was calculated.The simulation results verify the rationality and effectiveness of the damper structure design and magnetic circuit design.(3)The prototype model of rotary MR damper with T-shaped rotor was manufactured,and the damping torque test platform was built.The magnitude and variation of output damping torque under different loading current and rotation speed were analyzed through experiments.The results show that the designed rotary MR damper can achieve the expected goal,and can be used to reduce the vibration of scissor seat suspension.(4)The designed damper was installed on the shear seat suspension model,and the tension test was carried out on the damper test platform.The sinusoidal excitation was set,and the load current,vibration amplitude and vibration frequency were changed to observe the output damping force.The test results show that it is feasible to use the rotating MR damper with T-shaped rotor as the control element in the semi-active control suspension of automobile scissor seat.