本文提出不等長無槽間距 (Unequal Fluteless Spacing, UFS)的概念設計M1.2微型擠壓絲攻。常見的擠壓絲攻具有四個等長的圓弧邊，而UFS擠壓絲攻則具有八個不等長的圓弧邊及四個等長的平直邊。UFS的概念能降低擠壓絲攻的加工扭矩並使其壽命提升，而為了探討其降低扭矩的效應，本文將UFS擠壓絲攻應用於內螺紋的加工實驗。實驗採用的UFS擠壓絲攻和工件材質分別為碳化鎢材質和7075-T651鋁合金。本文考慮的UFS擠壓絲攻加工製程參數(或稱品質因子)有下孔徑及主軸轉速以及潤滑液濃度，採用中央合成設計法規劃並進行實驗，建立攻牙最大扭矩和內螺紋飽牙率的迴歸模型，完成參數最佳化設計的目的。此外，本文亦探討前述加工製程參數對內螺紋成型之扭矩和內螺紋飽牙率的影響。最大扭矩和內螺紋飽牙率迴歸模型，為運用統計軟體Minitab對實驗結果進行統計和變異分析(ANOVA)而建立，且被應用於參數最佳化設計。本文以望小最大扭距為目標函數，內螺紋飽牙率為限制條件進行最佳化設計，以期獲得最佳化的內螺紋飽牙率與最大扭矩。此外，本文依據加工製程參數最佳化的結果進行實驗驗證，結果顯示前述迴歸模型具有良好的預測性。;This study proposes a conceptual design of M1.2 micro-form taps with Unequal Fluteless Spacing (UFS). The common form tap has four arc edges of equal length, while the UFS form tap has eight arc edges of unequal length and four straight edges of equal. The concept of UFS can reduce the processing torque of the form tap and increase its life. In order to explore the effect of reducing the torque, this study applies the UFS form tap to the processing experiment of internal threads. The UFS form tap and workpiece materials used in the experiment are tungsten carbide and aluminum alloy 7075-T651, respectively. The processing parameters (or control variables) of the UFS form tap considered in this study are the lower aperture, the speed of the rotation and the concentration of the lubrication. The central composite design method is used to plan and conduct experiments to establish the regression model of the maximum torque and the fill rate of the internal thread. The regression model is used to complete the purpose of parameter optimization design. In addition, this study also discusses the influence of the processing parameters on the torque of the internal thread forming and the fill rate of the internal thread. Regression models of maximum torque and the fill rate of the internal thread were established for statistical analysis and analysis of variance (ANOVA) of experimental results using the statistical software Minitab, and were used in the parameter optimization design. In this study, the objective function is to take the desired maximum torque as the objective function, and the fill rate of internal thread is the limiting condition to optimization design, in order to obtain the optimized fill rate of internal thread and maximum torque. In addition, this study conducts experimental verification based on the results of the processing parameters optimization design, and the results show that the regression model of maximum torque and the fill rate of the internal thread have good predictability.
