Simulation Modeling And Analysis Of Heat Transfer Process Of Segmental Tire Mould

The quality and efficiency of tire vulcanization are directly related to the heat transfer process of live segmental tire mold.Due to the complexity of the structure of the live tire mold,it is difficult to directly measure the temperature distribution of the tire mold.The simulation technology can accurately model the heat transfer process of tire mold,effectively predict the temperature change and distribution of tire mold,guide the optimization of tire mold structure,and improve the quality and efficiency of tire mold design.In this paper,the simulation modeling and analysis of the preheating process of the live tire mold are systematically carried out.The main innovations are as follows.First,the structure and heat transfer process of segmental tire mold were analyzed,and the finite element transient heat transfer model of tire mold was established.The simplification basis of the tire mold structure,the setting method of the heat transfer boundary conditions,the division criterion of the finite element mesh,and the test method of the material thermophysical parameters were proposed.Besides of that,validation and analysis of finite element transient heat transfer model,structure simplification,boundary condition setting and finite element mesh were generated.Then the influencing factors of heat transfer simulation accuracy of tire mold are analyzed by simulation results.It is found that the convective heat transfer coefficient in the mold chamber has an important influence on the simulation accuracy,which is one of the important factors affecting the heating process of the tire mold,but it is difficult to accurately set up.This paper designs the test of tire guide ring temperature to determine the value method of convective heat transfer coefficient in the mold chamber.The simulation results show that the contact thermal resistance between different parts in the mold is a key factor affecting the temperature uniformity of the mold,and there is a significant nonlinear relationship between contact thermal resistance and temperature and pressure.The setting of the contact thermal resistance must be considered the influence of the molding temperature and pressure.Accurate setting of contact thermal resistance,the steady-state method is used to design the contact thermal resistance test experiment and developed the contact thermal resistance test platform.The thermal resistance curve of contact pairs was obtained,and the relational models of thermal resistance and temperature,as well as pressure were built,through testing of thermal resistances of commonly used tire mould materials and contact pairs.Considering the influence of molding temperature and pressure on thermal resistance parameters,the simulation accuracy of temperature field distribution was significantly improved.In order to verify the accuracy of the simulation,the temperature measurement experiment of the tire mold is designed.Through the temperature test of the upper side plate,the lower side plate and the three points on the pattern block,it is found that there is a large error in the transient temperature calculation during the heating process of the mold.Considering the dynamic change process of convective heat transfer and contact thermal resistance in the heating process,the correction criteria of convective heat transfer coefficient and contact thermal resistance were further established through the test results,and the simulation model of die heat transfer was optimized to improve the simulation accuracy.Finally,comparison of the temperature measurement tests of two sets of loop tire molds shows that the heat transfer analysis model of tire mold presented in this paper has a prediction deviation of 8.3 % for mold heating time and a maximum error of 5 °C for steady temperature calculation,which meets the requirements of engineering application.The established tire mold heat transfer simulation model is of great significance to guide the optimization design of tire mold.