Design And Research On Radial Scalable Inner Mold Mechanism Of Tire Vulcanizing Machine

Vulcanization is a pivotal process of tire manufacturing,endowing the uncured tire with exquisite surface pattern and superior performance by converting rubber property from plasticity to elasticity.However,the defects of incomplete expansion,asymmetric structure,and vapor condensation deposition in the existing vulcanization technology inferiorly affect the uniformity and dynamic balance performance of tires.Based on the direct pressure vulcanization technology,this paper designs a novel tire vulcanization equipment,i.e.,vulcanization inner mold drum(VIMD),which is used to replace the bladder in the traditional bladder vulcanization process.A series of research work is carried out on the design and optimization of the VIMD.The main work and research results are as follows:(1)In order to meet the design requirements of the VIMD and achieve a larger contraction ratio,the relationship between the drum-tile parameters and the contraction ratio was studied,and the maximum contraction ratio under different drum-tile parameters was obtained.Based on the degree of freedom design theory and configuration theory analysis,a new radial telescopic mechanism scheme is derived.The combined mechanism form of the link mechanism and the cylindrical cam mechanism and the symmetrical arrangement of the link mechanism are adopted to realize the independent movement of the wide and narrow-tile link mechanism,and effectively avoid the complicated control design.The mechanism is integrated based on the method of multi-position rigid body guidance,and the main dimensional parameters of the mechanism are determined,which meets the requirement of large contraction ratio.(2)A virtual prototype model of the VIMD was established through SOLIDWORKS,and the movement characteristics of were also researched and analyzed based on the dynamic analysis software ADAMS.Comparing different cylindrical cam track schemes,it is found that the design of increasing the circumferential groove can improve the self-locking ability of the link mechanism and the inclination angle of the drum-tiles after the link mechanisms are fully expanded,which enhance the overall dimensional accuracy of the VIMD.(3)Based on finite element commercial software ABAQUS,the VIMD is statically simulated to study its mechanical properties under vulcanization conditions.By comparing the simulation results of the overall finite element model of the link mechanism unit and the VIMD,it is found that the cutting-tile angle plays a role of self-locking,which not only reduces the overall force of the mechanism,but also improves the structural stability of the VIMD and reduces the radial and lateral errors,which improves the overall dimensional accuracy of the outer contour of the equipment.(4)The physical prototype of the VIMD was fabricated,and the feasibility and reliability of the scheme were verified through experimental tests.The torque test was conducted by setting up a torque test platform to verify the simulation model of VIMD.And the compression modulus of the link mechanism units were obtained through the quasi-static compression test.The results suggest that the VIMD has excellent stiffness and structural stability.