Research On The Rotary Welding Technology Of Plastic Automobile Clutch Master Cylinder

With the development of plastic and the increasing needs of lightweight products,the tendency of replacing steel with plastic for automotive parts has evolved from decorative parts to functional parts,and the plastic welding technology has been fully developed as well.Due to the significant amount of uncontrollable factors in welding,it is prone to exposing problems such as low welding strength,poor sealing,quality instability and so on.How to develop a set of stable,effective and high welding strength welding process was the key technique for solving the problems.According to the production demand,the research about the process of rotary welding in a plastic automobile clutch master cylinder manufacturing process has been worked in this paper,for figuring out the solutions.According to the enterprise standards,the clutch master cylinder should withstand the maximum pressure of 14 MPa.It is on this premise that the stress of the clutch master cylinder is analyzed by ANSYS,in order to check the strength of the pump.Furthermore,based on the analysis of pump structure and rotary welding machine working principle,the scheme of rotary welding surface and rotary welding fixture structure were designed.Taking the principle of rotary welding as a basis,and the physical properties of water absorption and crystallinity were as the research objects,an experimental design method for the influence of water absorption and crystallinity on weld strength was proposed with the purpose of enhancing the welding strength and improving the process.The process conditions of injection molding at 130 ℃ mold temperature and the process of drying the pump body at 120 ℃ for 12 hours was determined.Based on the experimental statistic method of CCD and RAM,a forecasting model is established.The melting point of clutch master cylinder material was obtained by DSC.Combined with the rotary welding mechanism,the welding parameter coupling model was constructed,and the relationship between friction surface temperature and the process parameters was analyzed as well.The validity of the formula was verified by a confirmatory experiment.After optimizing the welding parameters,the weld could withstand pressure far more than 14 MPa required by enterprise standards.Based on the summarized results of the plastic clutch master cylinder welding process research,developed the welding process,by using of high-pressure experiments and the durability experiments,to verify the feasibility of the welding process.Further,the manufacturing process flow of the clutch master cylinder assembly and the PFMEA were worked out.Through this study:effectively improve the weld strength.The research results were directly applied to the mass production process of the plastic clutch master cylinder and up to a yield of 98%.