| Variable medium diameter C-shaped coil spring is widely used in the suspension systems of vehicles to improve their lifespan by reducing or offsetting the lateral force applied to the dampers,and it can meet the requirements of installation,so,it can replace ordinary cylindrical coil springs well.Therefore,variable medium diameter C-shaped coil spring has become one of the research hotspots.At present,there is a lack of clear methods to calculate the mechanical properties and design the key parameters of variable medium diameter C-shaped coil spring,and the relationship between key parameters and mechanical properties has not been studied in depth.For the problem,the paper adopted theoretical calculations,simulation analysis,and experimental verification methods to analyze the mechanical properties of the variable medium diameter Cshaped coil spring,analyze the influence of key parameters,and design the spring’s key parameters.The following innovative research results are achieved:(1)When working,the variable medium diameter C-shaped coil spring becomes the variable medium diameter coil spring,and its mechanical properties are similar to the mechanical properties of variable medium diameter coil spring,the study simplified the variable medium diameter C-shaped coil spring model to the variable medium diameter coil spring to analyze the mechanical properties.The study used the Mohr integral to establish theoretical calculation methods for the axial stiffness and the steady-state constraint bending moment and the steadystate lateral stiffness of the spring,the maximum value method was used to calculate the compressive load of each ring.According to the superposition principle and elastic theory knowledges,when the variable medium diameter coil spring was subjected to axial load and lateral load,the calculation methods of axial deflection,lateral deflection and maximum composite shear stress were established.The reliability of the mechanical properties analysis calculation methods of variable medium diameter C-shaped coil spring simplified to variable medium diameter coil spring was verified.(2)The high diameter ratio required for variable medium diameter spring to maintain stability was derived,based on the established calculation methods of mechanical properties of the variable medium diameter coil spring,the calculation methods of relative axial deflection and steady-state relative lateral deflection of variable medium diameter coil spring were established,the variable medium diameter coil spring was subjected to axial load and lateral load,and its end remained stable,the theoretical calculation methods of axial deflection and lateral deflection at any position of the spring were established by using the superposition principle and Mohr integral,which laid the foundation for the design of the axial line of variable medium diameter C-shaped coil spring.(3)Based on the established calculation methods of mechanical properties of variable medium diameter C-shaped coil spring,the relationship between spring medium diameter,spring wire diameter,spring index,the number of effective working coils and mechanical properties of variable medium diameter C-shaped coil spring was analyzed.According to the optimal damping match of the shock absorber,the calculation formulas of the lateral force on the shock absorber were obtained.Based on the calculation methods of mechanical properties of variable medium diameter C-shaped coil spring,the calculation formulas of lateral force,and the calculation methods of relative deflection of variable medium diameter coil spring,the design methods of variable medium diameter C-shaped coil spring axis line and key parameters were established with stress and stiffness as constraints.Through simulation and experiment,the calculation methods of mechanical properties and the design methods of key parameters of the established variable medium diameter C-shaped coil spring were verified.The results show that it is reliable to simplify the variable medium diameter C-shaped coil spring to the variable medium diameter coil spring to derive the mechanical characteristics calculation formula,and the maximum deviation between the calculated value and the simulation analysis value and test results is not more than 5%,and the variable medium diameter C-shaped coil spring becomes the variable medium diameter coil spring when working,which can offset the lateral force on the shock absorber.This study can provide a certain reference for the forward design of variable medium diameter C-shaped coil spring. |
