Design method of leaf spring with few pieces and variable cross-section based on vehicle parameters

Abstract

The invention relates to a design method of a few-leaf variable-section plate spring based on vehicle parameters, and belongs to the technical field of suspension plate springs. The design method comprises the following steps: firstly determining the clamping rigidity required by the suspension and the root thickness he of an equivalent leaf of the few-leaf parabolic variable-section plate spring according to the vehicle parameters, the natural frequency of the suspension and an installation structure and a parabolic segment thickness ratio of the plate spring, and determining the root maximally allowable thickness [h2] according to the allowable stress and on-spring mass of a single-wheel suspension; then designing the number of the leaves N and the root thickness h2 according to he and [h2]; and finally, optimally designing the inclined segment length and the thickness and length of the end straight segment of each leaf according to the clamping rigidity requirement value and the inclined segment thickness ratio gamma. Through simulation verification, the parameter design value of the few-leaf variable-section spring meeting the vehicle requirement can be obtained by the method, so that the product design level and performance as well as the vehicle ride comfort are improved; and meanwhile, the design and test cost is lowered.

Description

technical field [0001] The invention relates to a vehicle suspension leaf spring, in particular to a design method for a few-piece variable-section leaf spring based on vehicle parameters. Background technique [0002] Compared with multi-piece superimposed leaf springs, the vehicle suspension with few pieces of variable cross-section leaf springs has a reasonable force, a balanced stress load, and saves materials and costs, realizes vehicle weight reduction, reduces wheel dynamic loads, and improves vehicle driving safety. At the same time, it also saves fuel, improves the efficiency of vehicle transportation, and has good economic and social benefits. It has been promoted and applied on many vehicles abroad. For leaf springs with a small number of variable cross-sections, an oblique section is usually added between the straight section at the root and the parabolic section, that is, a reinforced leaf spring with a few pieces of variable cross-section at the root is used, w...

AI Technical Summary

Problems solved by technology

In addition, due to the influence of the installation and clamping state, the stiffness of the small-piece variable-section leaf spring in the actual use of the vehicle is different from the stiffness in the free state

[0003] Although some people have previously given a design method for a few parabolic variable-section leaf springs, for example, Peng Mo and Gao Jun once proposed the design calculation of a few-piece variable-section leaf spring in "Automotive Engineering" Volume 14 No. 3 method, this method can only be designed for a small number of parabolic variable-section leaf springs with unreinforced roots and isostructured ends. The design requirements of the spring cannot meet the design requirements of the small-piece variable-section leaf spring based on the vehicle parameters

[0004] For the root-reinforced and non-isostructural small-piece variable-section leaf spring based on vehicle parameters, due to the calculation theory of deformation or stiffness under the installation and clamping state, and the equivalent thickness and split of the few-piece variable-section leaf spring Restricted by the design theory, no simple, accurate and reliable design method has been given so far. At present, most of them ignore the influence of the oblique line section of the root reinforcement and the non-isomorphism of the end, and directly approximate the oblique line section as a parabola section. All internal structures are regarded as the same, according to the required value of the free stiffness design, an approximate design is carried out for a few-piece variable-section leaf spring with reinforced roots and non-isomorphic ends. Therefore, it is difficult to obtain accurate and reliable parameter design values.

With the simulation of computer and finite element simulation software, although some people have used the ANSYS modeling and simulation method for the root-reinforced and non-isomorphic few-piece variable-section leaf spring, but this method can only be used for a given design structure. Simulation verification of the deformation or stiffness of a small number of variable-section leaf springs cannot provide accurate analytical design formulas, nor can it meet the rapid development of vehicles and the development of modern CAD design software for suspension leaf springs.

Images