Research On Intelligent Curing Technology Of Direct Pressure Shapping And Electromagnetic Induction Heating For High Performance Tire

Tire production needs to experience many complex processes.As the last step of the process,vulcanization determines the appearance quality and performance of the product.Current vulcanization technology uses high elasticity and low rigidity bladder to determine the tire inner contour based on the tire curing machine.Therefore,it is difficult to obtain a highly uniform geometric structure and mass distribution,resulting in poor dynamic balance and uniformity of the tire.In addition,heat by using steam or hot water in the traditional tire vulcanization.In the inner side of the tire,the heat needed for vulcanization is obtained indirectly from the bladder with low thermal conductivity,and the heat energy is mostly dissipated in the circulation of the pipeline.These results in low tire curing efficiency and large energy consumption.The relevance between of temperature to the stream pressure limits the optimization of the vulcanization process parameters.In order to improve the quality of tire,shorten the curing cycle and reduce the energy consumption,we present a direct pressure vulcanization technology for high performance tire.The technology uses a telescopic,high rigidity and thermal conductivity metal internal mold to replace the curing bladder,and adopts the electromagnetic induction heating method to simultaneously heat the internal and external molds replacing the traditional heat transfer mode completely.The main works of this paper are as follows:1?We put forward to two kinds of metal internal mold based on planar linkage and wedge guide mechanism,then made kinematic analysis and design.The virtual prototypes were optimized with FEM and developed successfully.We have developed a scheme of electromagnetic induction heating system and heating control method for curing mold of tire,then we simulated the internal eddy current distribution in the high frequency alternating magnetic field.The uniformity of temperature rise of electromagnetic induction heating is verified preliminarily.According to the special technical requirements of direct pressure vulcanization,We have developed a new type of hydraulic tire curing machine with the function of internal and external mold independent locked.We designed and manufactured the hydraulic system and industrial control system to meet the requirements of the experimental prototype.It provides sufficient experimental conditions for the subsequent study of the direct pressure vulcanization process for high performance tire.2?Through the analysis and experiment,we proved the pressure form of the direct pressure vulcanization process made positive effects on the physical and mechanical properties like tire framework,rubber hardness,tensile strength,elongation and loss factor etc.Based on the test results,such as the frontal unbalance mass,the radial force variation RFV,the lateral force variation LFV,the lateral force deviation LFD,the ply steel force PSF,the conicity force CON and so on,we investigated the lifting effect of rigid metal mold of high roundness on the mass distribution and the uniformity of the geometric size of the tire.In this paper,we set up the model of the clamping force of the internal and external mold for the direct pressure vulcanization process.3?We verified the temperature uniformity of the tire mold by electromagnetic induction heating.And we took the 255/30R22 specification tire as the research object,carried on the curing temperature measurement to the product.Considering the nonlinear of thermal and physical properties about materials,curing reaction heat and other factors,we used temperature data as boundary conditions,simulated the temperature field of tire by finite element method based on the electromagnetic induction heating.Then we studied the favorable effect of high temperature curing conditions on tire curing process,and further determined the best process temperature of tire vulcanization.4?Based on the set of fully automatic experimental prototype,and according to the best parameters,we carried out the continuous mass production of the 255/30R22 specification tire and the tire running test.At the same time,we analyzed the process characteristics in product curing efficiency and energy consumption of direct pressure vulcanization process.The results show that in the direct pressure vulcanization process,the tire curing cycle is shortened by 11.06%compared with traditional process,the energy consumption decreased by about 86%than the traditional process.The tire appearance inspection,laser speckle nondestructive testing and product performance laboratory tests are all up to the national standard.It can be preliminarily confirmed that the pressure vulcanization process for high performance tire has good industrial application prospects.