| The adjustable damping shock absorber can provide different damping characteristics according to the road condition,taking into account the stability and comfort of the car,so it has broad market prospects and practical value.The proportional valve is the core component of the adjustable damping Shock Absorber to adjust the damping characteristics,and its output characteristics have a crucial influence on the damping characteristics of the damper.Therefore,this paper has carried on related research on the steady-state characteristics and dynamic characteristics of proportional valves.The main contents are as follows:(1)A direct-acting proportional valve for an adjustable damping shock absorber is proposed.Then the working principle and structural characteristics of the valve-controlled adjustable damping shock absorber and proportional valve are analyzed.The calculation and analysis,structural design and parameter check of key components such as proportional electromagnet and spool were carried out.(2)The finite element simulation model of proportional electromagnet was established,and the influence of key structural parameters of electromagnet on electromagnetic force was analyzed by Ansoft simulation software.The results show that the electromagnet has good displacement-force and current-force characteristics when the bowl mouth depth is 3.9 mm,the magnetic isolation ring angle is 35°,the boss chamfer length is 0.2 mm,and the radial clearance is 0.3 mm.Further simulation of the model shows that when the voltage amplitude is 24 V,the rise time of the electromagnetic force under the step excitation signal is about 40 ms,and the cutoff frequency of the electromagnet is about 36 Hz.(3)According to the force balance equation of the proportional valve spool,combined with static magnetic force,steady-state hydraulic power,etc.,the displacement characteristics of the spool and the differential pressure flow characteristics of the valve are obtained under steady-state conditions.Based on the theory of kinematics and electromagnetism,the differential equation of the valve core motion is established and the transfer function of voltage to spool displacement is obtained.The simulation of the proportional valve is carried out by Matlab software,and the rise time and response time of the valve core are obtained.Important dynamic characteristics such as amplitude bandwidth and phase bandwidth,and determine the main factors affecting the dynamic characteristics of the proportional valve.(5)The proportional valve experimental test system was designed and built.The differential pressure flow characteristics of the proportional valve under different excitation currents were studied experimentally.The experimental results and calculation results were basically the same.A test method for the frequency response characteristics of the proportional valve is proposed.The amplitude and phase width of the valve are measured at 28 Hz and 20 Hz,respectively. |
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