难加工材料攻丝摩擦扭矩的试验研究

Experimental Investigation of Friction Torque for Tapping Hard-to-cut Materials

分析了攻丝过程及退回过程两阶段丝锥的力学特征,在此基础上分别建立了切削扭矩和摩擦扭矩力学模型。针对难加工材料GH4169和TC4,采用M6标准丝锥进行攻丝试验。结果表明:摩擦扭矩占攻丝扭矩的比率分别为45%和55%;针对45钢,摩擦扭矩则很小。可见,摩擦扭矩大是GH4169和TC4攻丝困难的主要原因。

Based on the analysis of tap mechanics feature in both cutting and withdrawal process, the mechanical models of tapping moment of torque and friction one were created respectively in the paper. The standard tap of an outer diameter of M6 was utilized for tapping difficult-to-machine materials of GH4169 and TC4. The test results indicated that the leading cause of difficult tapping in GH4169 and TC4 was the largeness of their friction torques which was about 45 % and 55% of tapping torque respectively but a lesser percentage for 45 steel.