線性與傳統伺服馬達CNC三軸銑床加工 420不鏽鋼之表面粗糙度影響探討

The Influence of Surface Roughness of 420 Stainless Steel Processed by Linear and Traditional Servo Motor Three-axis CNC Milling Machine

林宜萱(Yi-Hsuan Lin)

指導教授 ： 王銀添

淡江大學/工學院/機械與機電工程學系碩士班/碩士(2021年)

https://doi.org/10.6846/TKU.2021.00862

摘要

本研究目的為利用線性馬達和伺服馬達驅動之CNC加工機，加工420預硬不鏽鋼(模具鋼)，探討其最佳銑削參數組合，以及在高速銑削加工下兩者機台對加工工件的表面粗糙度之影響。本研究會先應用田口方法，求出420預硬不鏽鋼之最佳化銑削參數，實驗選用4個控制因子3水準：主軸轉速、進給率、刀間距和加工方式(平行、環繞、3D等間距)。再以兩種不同馬達驅動之CNC機台各銑削一工件來驗證最佳化銑削參數組合之推估值的再現性。另外，在高速銑削方式加工時，比較兩種機台對銑削後工件表面粗糙度之影響。
實驗結果可得知主軸轉速14,000rpm、進給率500mm/min、刀間距0.01mm、3D等間距銑削方式為最佳化銑削參數組合，將銑削方式微調成平行加工後，其推估表面粗糙度R_a值能達到0.244μm。兩種不同馬達機台在最佳化銑削參數條件加工下，皆能達到實驗的再現性，表面粗糙度R_a值分別為0.246μm和0.247μm。另外在高速銑削方式加工下，線性馬達之機台的工件R_a值為0.222μm相較於伺服馬達以高速銑削方式加工之工件R_a值0.256μm，更能表現出其加工時機台的穩定性。

關鍵字

420不鏽鋼 ； 表面粗糙度 ； 田口方法 ； CNC三軸銑床 ； 線性馬達 ； 伺服馬達

並列摘要

The purpose of this study was to process 420 prehardened stainless steel (die steel) by a CNC machine driven by a linear motor and a servo motor, and to investigate the optimum milling parameter combination and the effect of the two machines on the surface roughness of the workpiece under high speed milling. In this study, the optimal milling parameters of 420 prehardened stainless steel were obtained by using Taguchi method. Four control factors and three levels were selected in the experiment: spindle speed, feed rate, tool spacing, and processing method (parallel, surround, and 3D equidistance). The reproducibility of the estimation based on the optimal milling parameters was verified by milling one workpiece per CNC machine driven by two different motors. In addition, the effects of the two machines on the surface roughness of the milling workpiece in high speed milling were compared.
The results showed that the optimum milling parameters were the spindle speed of 14,000rpm, feed rate of 500mm/min, cutter spacing of 0.01mm and parallel milling. The R_a value of surface roughness could reach 0.244 μm. The surface roughness R_a values were 0.246 μm and 0.247 m, respectively. The R_a value of the workpiece of the linear motor was 0.222 μm compared with the R_a value of 0.256 μm of the workpiece of the servo motor in the high speed milling mode, which showed the stability of the machine during milling.

並列關鍵字

420 Steel ； Surface Roughness ； Taguchi Method ； 3-axis CNC Milling Machine ； Linear Motor ； Servo Motor

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