OPTIMIZATION OF COIL SPRING FOR THREE WHEELER

Abstract: The helical compression spring used in suspension system or shock absorber is a mechanical device designed to smooth out or damp shock impulse and dissipate kinetic energy. A helical coil compression spring which used in transport three wheeler is belonging to the medium segment of the Indian automotive market. The detailed assessment of the problem of three wheeler vehicle's front suspension system is studied in this project. It is observed that, the vehicle drifts towards one side due to high weight of suspension system. This problem can be solved by redesigning and optimizing front suspension spring. So for this purpose the static stress analysis using finite element method has been done in order to find out the detailed stress distribution of the spring. The design process can be viewed as an optimization process to find structures, mechanical systems, and structural parts that fulfill certain expectations towards their economy, functionality, and appearance. The experimental investigation is performed to calculate the stiffness and vertical acceleration of helical compression spring. The calculated results are to compare on common scale with theoretical and software results. After optimization the spring checked for its structural strength and if it did not meet the strength requirements the spring had to be redesign until the strength was meeting. Once optimization of the spring was done prototype of the spring were made. These springs have to face very high working stresses. The structural reliability of the spring must therefore be ensured. For the present experimental investigation the SP ST GRD II material was taken for spring manufacturing and performs the static and dynamic test. In static test the universal testing machine was used to find stiffness of spring and quarter car test rig used to find the vertical acceleration of helical compression spring.

Keywords: Deflection, coil spring, optimization, FEA, etc.