Optimization of chip repose angle in dry hobbing machine considering minimum thermal accumulation on workbench

The thermal deformation problem is quite serious for the workbench of the environmental dry hobbing machine due to the thermal accumulation of hot chips. A better understanding of the quantity and optimization of the chip repose angle is quite necessary to reduce the workbench thermal deformation. Hence, this paper focuses on the chip repose angle modeling and optimization for the workbench of the dry hobbing machine. Firstly, the dynamic flow characteristics of chips are clarified by analyzing the chip generation mechanism and the motion trajectory of dry hobbing. Then, the chip repose angle is mathematically characterized with consideration of the chip rolling characteristics, with which a chip repose angle optimization model is established by minimizing the thermal accumulation on the workbench, and a chip repose angle optimization method is proposed based on the intelligent optimization algorithm. Finally, the effectiveness of the proposed method is analyzed through the simulation experiment on the dry hobbing of automotive reverse gear. The results show that the maximum overall thermal deformation is reduced by 8 μm for the workbench, and the skewness is reduced by 32% for the workbench spindle with the help of the proposed optimization method. The study provides an effective solution for the quantitative analysis and optimal design of chip repose angle on the workbench of the dry hobbing machine.