高速小钻头温度与热应力场特性研究

基于传热学和金属切削理论,建立了某型高速钻头温度场模型.利用有限元法,模拟该钻头在典型工况的温度场分布及变化规律,研究了切削速度等参数对温度场的影响,得到了钻头在温度载荷下的应力和变形,计算结果表明,高速钻削最高温度出现在钻头尖部,沿轴向逐渐降低,对于小直径钻头心部与表面温差不显著;最高温度随着转速升高而升高,达到一定值后上升趋势逐渐变缓进而下降;刀具热变形较小,但热变形量可能会影响加工精度,应调整刀具材料或加强冷却;切削温度基本不影响其强度.

Study on Temperature and Stress Field of High-speed Micro Drill

The temperature field model of micro - drilling spindle system was built by based on heat transfer theory and metal cutting theory. The distribution of temperature field is simulated using FEM. The influence of drilling speed on temperature field is proposed. The stress and deformation of drill with heat load are obtained. The conclusion is that the hottest section of drill is the head, and temperature is gradually reduced along the drill axis. The difference of drill temper- ature between surface and the core is not obvious to small size drill, the temperature rises as the drill speed increases, but uptrend would be slow and then falls. The heat deformation may in affect working precision. The material and cooling should be improved. The heat load can not affect the drill strength.