Study On The Design Of Stepped Vulcanization Mould And Mechanical Properties Of Tire

With the continuous development of the automobile industry,the functional requirements of the automobile are constantly upgrading,which puts forward higher requirements for tire performance.Vulcanization is an important process affecting the quality of finished tire.The improvement and innovation of tire vulcanization equipment and manufacturing process can effectively improve the performance of tire and meet the requirements of green,safety and energy saving of automobile.Aiming at the defects of the traditional central mechanism capsule,the direct press vulcanization technology is proposed.The central mechanism adopts the metal internal mold with good thermal conductivity and high rigidity to improve the quality of the tire.However,the existing direct press vulcanization internal mold does not have a clear scope of application.It can only be used for 255/30R22 specification tires.Other specifications of tires cannot judge whether the internal mold interferes before design,and the value of the internal mold structure parameters The optimal solution is not achieved,and there is still the problem of friction on the inner surface of tire when the mould is demoulded.The research content is to build an improved structure form on the basis of the conventional direct press vulcanization mould,to put forward the step type direct press vulcanization internal mold,to make up for the deficiency of the radial space through the axial space,and to calculate the application scope of two kinds of direct press vulcanization internal mold and the optimal structural parameters of the internal mold;to establish the step type direct press vulcanization internal mold digital model of 235/45R18 tire,In order to facilitate the demoulding of the metal internal mold,the tire with gradual cross-section was proposed and its mechanical properties were simulated.The main contents of this paper are as follows:(1)In view of the small application scope of the direct press vulcanization internal mold,the structural form of the step type direct press vulcanization internal mold is proposed.The application scope of the conventional direct press vulcanization internal mold and the step type direct press vulcanization internal mold is studied.The physical model and mathematical model of the conventional direct press vulcanization internal mold are established.The optimal solution of the structural parameters of the direct press vulcanization internal mold is obtained by matlab calculation,and the conventional direct press sulfur is defined The application scope of internal mold and step type direct press vulcanization internal mold as well as the judgment formula for any tire specification are extended,and the direct press vulcanization technology is applied to a wider range of specific tire specifications.(2)Based on the requirement of tire specification and the geometric relationship between parts,the formula is used to calculate the size parameters of each part,and the model of direct vulcanization internal mold is established with the aid of UG NX,and the three-dimensional digital model is simulated to verify the rationality of internal mold kinematics without interference.(3)According to the actual curing conditions,the finite element mechanical model of 235/45R18 tire internal mold is established,and ABAQUS is used to simulate the mechanical properties of the internal mold finite element model,analyze the stress distribution and displacement change of the internal mold,and verify that the overall internal mold meets the strength requirements and can be used normally.(4)In view of the problem that the inner surface of tire is easy to be scratched when the metal internal mold is demoulded,the concept of gradient section tire is proposed with reference to the draft angle of plastic parts,the geometric model of gradient section tire of 235/45R18 specification is established,the finite element model of tire mechanical performance simulation is established according to the inflation and static load conditions,and the mechanical performance parameters of ordinary section tire and gradient section tire are compared To verify the feasibility of gradient section tire.