| The maneuverability and driving comfort are an important evaluation index of a vehicle.Due to the structure of the damper of traditional Mc Pherson suspension of the vehicle,there is a lateral load unexpected inevitably.The load will affect the maneuverability and driving comfort of a vehicle and reduce the service life of its damper.Although using inclined spring,inclined spring seat and other methods the lateral load can be reduced,with the improvement of suspension design standards,these measures are difficult to meet the more stringent design requirements.Among the lots of measures put forward by domestic and foreign scholars,the use of a side load spring instead of ordinary spring is the most reasonable,but there is no design method and standards for using.With the continuous development of CAD/CAM/CAE technology and they have got a wide successful application in the engineering.Adopting modern CAD/CAM/CAE technology as a powerful tool for the design and analysis of the side load spring,for the mechanical properties and vibration characteristics and optimization design of the side load spring of the McPherson suspension,the research contents of this thesis are as follows:(1)On the basis of introducing the working principle of the side load spring,the basic parameter design and force analysis of the spring are studied.Under the premise of the horizontal and vertical stiffness requirements of the side load spring,the preliminary determination method of the side load spring of axis curve is given.According to the least squares method,the non-iso-curvature curve of the side-load coil spring is fitted,and the centerline equation of the side load spring is determined as a quadratic curve equation.(2)Using the method of multi-body dynamics and nonlinear finite element method,ANSYS and ADAMS software were used to establish the rigid-flexible coupled model of a side load spring.The 3D solid model of the vehicle is established and imported into ADAMS.The multi-body dynamics model of a vehicle system is established.The simulation results show that the lateral load of the shock absorber is significantly reduced and the driving comfort of the vehicle is improved.(3)The stiffness parameters of the side load springs are obtained by ADAMS simulation,which are taken as the basic constraints of the optimal design of the spring,and the response surface method that is embedded in ANSYS is used to optimize the parameters of the side load springs.The optimized spring makes the vertical and lateral stiffness of the side load spring meet the design requirements in real time no matter the spring is in the no-load,half load,full load and compression,and reduce or even eliminate the lateral force on the shock absorber.The results of this study can provide a reference for the design of side coil spring. |
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