Research On Vehicle Suspension Leaf-spring Of The End Non Equal Strctural Slash Type Variable Cross-section

Research on leaf spring of slash type is aimed at end equal structure leaf spring mostly,that for the end non equal structural slash type leaf spring,and as a result of the rigidity,deformation,equivalent thickness,split design and prestress matching,camber design ect constraints of mechanical models.The analytic expression of the forward design for the end non equal structural slash type leaf spring,which has not been given so far,and draw lessons from the design method about experience and experiment for multi leaf spring as before.Although the traditional design method of leaf spring can meet the design requirements,but the precise design for the suspension leaf-spring of slash type,forward development and intelligent production and manufacture that are difficult to achieved,also it is inconsistent with the current era of high quality and low energy consumption.This article aims at analyzed about the end non equal structural slash type leaf spring’s problems in the design process,which the specific research contents are as follows:(1)The mechanical model of slash type variable cross-section leaf spring is established,then take advantage of the deformable differential equation,obtained the deformation of a single slanted steel plate spring at any location and stiffness analytical expressions,and analyzed the influence of dimension parameter to leaf spring deflection and stiffness of spring parameters.Analysised the stress of a single slanted steel plate spring at any location,the formula for calculating the maximum stress of a single slanted steel plate spring is obtained,and the influence of oblique line thickness ratio on the maximum stress of spring is analyzed.Through example calculation and simulation verification,which is shown that the formulas for calculating the deformation,stiffness and stress of slash type leaf spring are accurate.(2)The stress and deformation of superimposed oblique-line leaf spring were studied,and the analytical expression of equivalent thickness of superimposed slash type leaf spring is derived,after the relationship between the stress of superimposed leaf spring and the thickness of leaf spring root was studied,and the maximum allowable thickness of the split design is given.Under the condition of satisfying rigidity and strength,that the split design is carried out on slash type leaf spring,and determined the number of split pieces of the slash type leaf springs and the thickness of the leaf spring at any position.(3)According to the relationship between the maximum stress and the allowable stress at the root of the oblique line type leaf spring,that prestress matching is carried out on the leaf springs,and according to the relationship between clamping stiffness and full load,the analytical expression of initial tangent arc height is established.Then according to the relationship between the maximum load carried by the main leaf spring and the deformation of the leaf spring,that design method for established limit stroke of slash type leaf spring.On the basis of the prestress matching of the slash type leaf springs and the design of the initial tangent arc height of the assembly,and the free arc height of a slash type leaf spring is calculated analytically,also the size parameters affecting the free arc height of the spring are analyzed.(4)According to the theoretical calculation formulas of deformation,rigidity and stress of slash type spring,and the deflection and stiffness of the oblique-line spring are verified by theoretical calculation and simulation.And the split design of oblique line variable cross-section leaf spring that end non equal for vehicle suspension is carried out,after commission leaf spring manufacturing enterprises for trial production,and the stiffness characteristic test was carried out,that the load-deformation experimental curve of oblique line type leaf spring is obtained,which can be used as a reference for the forward design of the end non equal structure spring.Through simulation verification and stiffness characteristic experiment that the results show that the analytical expression of the stiffness of the oblique-line type leaf spring is correct.The mechanical model of equivalent thickness and split design of superimposed oblique-line spring is reliable.The matching of the prestress of each leaf spring and the design of the arc height and the limit stroke meet the requirements.Therefore,the research has an important theoretical significance and practical application value for the design of the end non equal structural slash type variable cross-section leaf spring.