Study On Quality Control Of Surface Quenching For Large Automobile Panel Dies

Large automobile panel mould is an important tool used in the automotive industry,the level of mould technology affects the level of the automotive industry.Because of the need for more than ten thousand times the working life of large mould,so improve the life of the mould is an urgent problem to be solved in the automotive industry.At present,most of the automobile enterprises adopt the method of surface flame quenching to improve the hardness and strength of the mould surface in order to prolong the working life of the mould.However,due to the flame quenching mainly depends on the experience of workers to determine the heating temperature,will lead to over burning,underbumt,affecting the quality of quenching.Therefore,this paper put forward a new method based on the six axis high frequency induction quenching machine,which is used to process the surface of the mould by scanning high frequency induction heating.Thus,this paper studied mould high-frequency induction quenching.The main contents of this paper are as follows:(1)The mathematical model of the high frequency induction heating system is established by using the Maxwell equations,the Heat transfer theory and the Multi field coupling method.Using finite element analysis method of numerical simulation,simulation of the induction quenching process of high frequency induction heating process of mould steel in different power and frequency,the Avrami equation and the Magee formula are used to calculate the variation of austenite and martensite in the heating process,quantitative analysis of the influence of heating frequency on heat penetration and heating power on the depth of hardened layer depth.According to the design requirements of mould surface quenching,the quenching temperature is determined by simulating the change of microstructure.(2)The hardware control system of six axis high frequency induction quenching machine tool based on PC+Clipper is developed.For the control of complex mould surface induction quenching requirements,based on six axis induction quenching machine tool has been developed on the open CNC system PMAC,designed the electrical control circuit of the machine tool,and set up the hardware platform of machine tool.The hand control unit of the NC machine tool is carried out the two development,and the data acquisition is realized in the teaching mode.Aiming at the possible failure of the system,the function of self-locking protection of the machine tool is developed.(3)The temperature control system of the scanning high frequency induction quenching is designed.In view of the problems of time delay and nonlinearity in the temperature control of scanning quenching,based on the fuzzy control theory,the fuzzy controller of quenching temperature is designed,by adjusting the operating speed of the feed system,the adaptive control of the temperature of the mould surface is realized.(4)The experimental study on the induction hardening of mould.The six axis high frequency induction hardening machine is used to test the data of the complex mould.The results show that the open CNC system has perfect function and reliable performance.The feasibility of the fuzzy control system of quenching temperature is verified by the scanning temperature control quenching experiment.And the correctness of the mathematical model of the high frequency induction heating system is verified by the quenching process experiment and metallographic analysis.