Research On The Equipment And Process Of No Bladder Tire Vulcanization

Tire is an important part of the automobile, its performance is directly related to the safety and stability of the vehicle. Vulcanization is the last step in tire production, which has a direct impact on the quality of tire products.The steam or hot water heating is adopted in the traditional process to provide the temperature and pressure required for vulcanization by passing it into the flexible bladder. Due to the low thermal conductivity and the limited life of the bladder, the vulcanizing efficiency is low and the cost is high.In this paper, we propose a kind flange clamping mechanism for no bladder vulcanization process. The hydraulic vulcanizing machine is modified by replacing the central mechanism by the upper and lower flange clamping mechanism. The mechanism plays a role in fixing tire during vulcanizing. The inner cavity of the tire is vulcanized by nitrogen. During vulcanization, the nitrogen is directly injected into the inner-liner of pre-vulcanized tire and the external mold is heated by the electromagnetic induction to replace hot water or steam heat transfer medium. Therefore, the tire vulcanizing efficiency is improved, and the cost is greatly reduced. The main research contents are as follows:(1) Based on the principle and the requirement of no bladder vulcanizing process, a kind of equipment is designed successfully for 255/30R22 tire-the flange clamping mechanism. It adopts a connecting rod type actuator. We had the kinematic analysis and theoretical calculation of the mechanism. A mathematical model is established about taking the piston rod of the central mechanism to drive the whole mechanism and the design parameters of the mechanism is determined to keep the normal motion of the mechanism and to achieve the purpose of loading and unloading the tire. The virtual prototype technology is used to verify the rationality of the design.(2) After transforming the traditional central mechanism into the flange clamping mechanism, the sealing position is determined based on the analysis of the internal structure of the vulcanizing machine. The sealing form of internal mold is designed reasonably in order to keep the high pressure. The scheme of the electromagnetic heating system is determined, and the transformation of the middle mold sleeve and the hot plate on the traditional structure are carried out.(3) The finite element analysis software ABAQUS was used to simulate the structural stress and deformation of the flange clamping mechanism. The structural strength of each part is checked and the structural optimization of the main force component is carried out. Finally, the overall design scheme of the flange clamping mechanism is determined.(4) The process flow of no bladder vulcanization is designed, and the automatic operation sequence of the vulcanizing machine is determined. The heating experimental research is developed to compare the temperature change of different rubber layers under the condition of no bladder vulcanization with traditional vulcanization. The results show that under the condition of no bladder vulcanizing process, the tire can obtain higher vulcanization temperature and the temperature rise speed, the higher heating efficiency and the better products quality. The production process and the production cost of the bladder are analyzed. The results show the production and equipment cost of no bladder vulcanization are lower compared with traditional vulcanization,and the whole vulcanization process is simplified.