Research On Vertical Stiffness Of Hyperbolic Air Spring And Design Of Forming Drum

Rubber air springs are one of the key components of vehicle vibration control and have good vibration and noise damping capabilities for high frequency vibrations.The indicators of stiffness,displacement,load and internal pressure are important indicators to characterize air springs and have strict national and industry standards.With a new generation of drivers in our country,the stability of vehicle operation and ride comfort requirements have been further improved.On the other hand,our country’s governance of the "overload" problem is also being strengthened.So that the application of rubber air springs constantly expanded,the product design is more scientific and reasonable,the manufacturing equipment of rubber air springs also continue to put forward new requirements.This paper used finite element software such as Abaqus,Fe-safe,etc.,and took the hyperbolic bladder type rubber air spring and the air spring forming drum as the main object of study,through the finite element analysis method,numerical analysis method,orthogonal test method,etc.,to simulate and analyze the parameters related to the air spring design,and derived the primary and secondary relationships of the influencing factors.In order to improve the design of the forming drum mechanism,the existing air spring forming drums have the problems of single size and uneven unloading,which can satisfy the production of various sizes of air springs to a certain extent and improve the adaptability of the forming drum.The main research in this paper is as follows:(1)Taking the hyperbolic bladder air spring as an example,the non-linear characteristics of the air spring were investigated,and a finite element model of the air spring was established to obtain load-displacement diagrams and stress diagrams in compression for the vertical stiffness of the hyperbolic bladder air spring with different cord parameters.An orthogonal test of the factors influencing the vertical stiffness of the air spring was designed,and the primary and secondary relationships of the influencing factors were obtained through ANOVA:number of cord layers>cord angle>modulus of elasticity>cord radius>cord spacing.Through ANOVA the significance of the influencing factors was obtained:the influence of the cord angle on the vertical stiffness of the air spring was significant,the influence of the number of layers of cord on the vertical stiffness of the air spring was highly significant and the influence of the modulus of elasticity,cord spacing and cord radius on the vertical stiffness of the air spring was not significant.(2)The dynamic simulation of hyperbolic air spring was carried out by using Abaqus and Fe-safe software.The influence of cord angle on the vertical dynamic rigidity and fatigue life of hyperbolic air spring was studied.The simulation results were verified by combining existing research and manufacturer data.The results show that the fatigue life of the hyperbolic air spring increases with the increase of the cord angle,and the damage area of the air spring is concentrated in the bend of the interface between the upper cover plate and the base and the air spring bladder.(3)The kinematic analysis of the forming drum mechanism of the air spring forming machine was carried out,and the problems of the existing air spring forming drum were clarified.Studied the drum parameters and radial expansion ratio,proposed a new radially movable air spring forming drum mechanism,and used Pro/E software to model the mechanism and assemble the virtual prototype,so that the forming drum can achieve radial scalability,and can satisfy the production of a variety of sizes of air spring models.The adaptability of the forming drum has been improved.