Research On Key Technology Of Electromagnetic Induction Heating Of Shrink-fit Tool Holder And Development Of Device

At present,the application of heat-fitting tool systems in high-speed CNC machine tools is becoming more and more popular.Shrink-fit tool holder is an important part of the heat-fitting tool system,because they are mostly used in induction heating,which has many advantages sunch as high efficiency,environmental protection,and easy to control.Because of their high clamping accuracy,they are compared with other tool holders,shrink-fit tool holders have good rigidity and dynamic balance,so it has been widely used in high-speed cutting.The key technologies of shrink-fit tool holder heating is studied in this subject.Based on the basic principle of electromagnetic induction heating,the power required during the heating process of the tool holder is analyzed.ANSYS finite element analysis software is used to establish the coil and tool holder model,according to the magnetic field distribution,combined with the special cooperation of the tool holder and tool,The coils of different structures are analyzed,and finally a reasonable induction heating coil is designed.Based on the magnetic field distribution of this coil structure,combined with the actual material parameters of the tool holder,a magnetic-thermal-structure coupling analysis model is established to analyze the temperature field and strain field of the tool holder during heating.The theoretical heating temperature and thermal fatigue life of the tool holder are also studied.Based on the above theory and simulation analysis,the tool holder shrink-fit device that can heat domestically-made tool holders of different sizes is designed,first of all,according to the electromagnetic induction heating principle and the actual needs of tool holder heating,the hardware system framework of the shrink-fit device is designed.It mainly includes three-phase rectifier circuit,full-bridge inverter circuit,drive protection circuit,coil and load circuit,button and display module and main control circuit.A control scheme with STM32F103RBT6 as the main control chip and IR2213 as the driving chip was formulated.The software solution is formulated according to the actual situation of the tool holder heating,including the initialization module,the drive signal generation module,the ADC sampling module,the interrupt module and the parameter adjustment module.The designed software program can adjust various heating parameters,and can realize the heating of tool holders of different specifications.Finally,the developed tool holder hot loading machine is used to heat the shrink-fit tool holder,a large number of heating experiments are carried out on the BT40-SF06 tool holder and BT40-SF10 tool holder of Chengdu Sentai Inge Tool Company.The relationship between the final heating temperature and various heating parameters is studied,and the reliability of the device is verified.