It has the advantages of compact structure and stable operation, and is the most widely used mechanical transmission system. As China moves towards becoming a powerful country in equipment manufacturing industry, there is an urgent need to improve the process level of basic parts such as gears. In the field of multi frequency induction quenching surface hardening technology, the dual frequency induction quenching process of bevel gear is explored. In this paper, the three-dimensional finite element model of bevel gear is established in the finite element software ANSYS. By using the method of segmented dual frequency induction heating, the dynamic simulation of dual frequency induction heating process is realized, and the dual frequency induction heating process is analyzed. Finally, the experimental platform was built to carry out the dual frequency induction heating experiment, and the quenching and cooling process was simulated.
The phased research results obtained are as follows:
(1) According to the structural characteristics of bevel gear and the design principle of gear induction coil, the “tooth wound” induction coil for the induction quenching process of bevel gear is designed, and the structural parameters are optimized.
(2) Combined with the characteristics of induction heating technology, a three-dimensional finite element model for the exploration of dual frequency induction heating process of bevel gear is established, and the numerical simulation of segmented dual frequency electromagnetic thermal coupling process is successfully realized in the finite element software ANSYS. Comparing dual frequency induction heating with single frequency induction heating, it is pointed out that dual frequency induction heating can obtain a more uniform temperature field model.
(3) The dual frequency induction heating process is analyzed from many angles, and the effects of medium and high frequency output time ratio and switching frequency ratio on the dual frequency induction heating process of bevel gear are explored. The distribution characteristics and uniformity of dual frequency induction heating temperature field are analyzed from the tooth profile direction and tooth width direction of bevel gear. It is pointed out that a more uniform bevel gear temperature field model can be obtained by optimizing the process parameters such as medium and high frequency current density ratio, frequency ratio and switching time.
(4) The initial microstructure field of quenching and cooling is defined by simple temperature method, and the microstructure of bevel gear quenching and cooling process is successfully simulated by DEFORM software. The depth and uniformity of the hardened layer are quantitatively analyzed from the distribution of the microstructure content on the surface of the bevel gear. It is revealed that compared with the single frequency induction quenching method, the dual frequency induction quenching method can obtain the hardened layer evenly distributed along the tooth profile.
(5) Using the medium and high frequency induction heating equipment in the laboratory, the dual frequency induction heating experimental platform was successfully built, and the dual frequency induction heating experiment of bevel gear was carried out. The four temperature values on the outer surface of the bevel gear are detected and recorded by the temperature measuring device, and the experimental data are compared with the simulated data. The results show that the simulated temperature rise data is basically consistent with the experimental temperature rise data, which verifies the correctness and effectiveness of the finite element simulation.
Although some phased results have been achieved, some aspects still need to be improved.
(1) This paper mainly explores the dual frequency induction heating process of bevel gear, and analyzes the influence of various factors on the dual frequency induction heating process. The orthogonal method is not used to comprehensively analyze the influencing factors of bevel gear dual frequency induction heating process, and the best temperature field model is obtained.
(2) According to the temperature field model of bevel gear after induction heating, the initial microstructure field of quenching and cooling is defined. If the microstructure field can be simulated directly in the induction heating process, the accuracy of microstructure simulation will be higher. Moreover, the quenching and cooling process adopts flow field analysis, which will be closer to the actual production.