臺灣博碩士論文加值系統

在機械零件加工中，加工精度在製程中扮演極為關鍵的角色，尤其在薄件加工時，隨著材料被移除，工件剛性降低，薄工件便容易受切削力的影響而產生彈性變形，使加工精度下降。而在傳統製程中，通常藉由多道次的加工，減少刀具對工件產生的切削力，避免工件彈性變形問題的產生，但此方法便會使切削效率降低。因此，本文為了能同時確保成品加工精度及切削效率，允許工件在適度範圍內產生彈性變形，並藉由修正刀具路徑之方法，補償因彈性變形所產生之刀尖點與工件間之誤差。
首先藉由實驗求得該工件、刀具材料之切削常數，再藉由加工參數預測切削力大小，並將所預測之切削力做為負載，對工件進行結構分析，以求得工件之彈性變形量，再藉由此變形量結果，於NX CAM軟體中建立出補償後的加工路徑，最後以此加工路徑進行切削實驗。本文使用智慧型刀把(Sensory tool holder)做為切削力量測設備，其可直接量測刀具端之切削力，此外，本文建立一套流程進行量測數據的座標系統轉換及定位，以方便後續所量測之數據可在同一座標系統下進行分析。
本文以三軸加工薄板為實例，驗證工件材料 SS316L 及刀具材料鎢鋼之切削力預測值與實驗值，並應用體積補償方法進行切削實驗，最後使用三次元量床對原始加工路徑與補償後加工路徑之成品進行加工精度之比較。
本文於 MATLAB 中建立三個主要程式介面：切削常數計算程式、切削力模擬程式、建立補償路徑之程式，對於不同的工件、刀具材料，工件幾何模型及加工方式皆適用，使用者能以方便簡單的操作，快速獲得體積誤差補償之路徑，以解決薄件彈性變形之問題，同時提升產品精度及加工效率。

The purpose of this study is to improve the machining precision and processing efficiency in the milling process of thin workpieces. In the case of thin workpieces, elastic deformation is the main problem causing volumetric errors during milling. To solve this problem, the tool path is modified to compensate for volumetric error. First, the cutting forces generated during the milling process can be predicted from a cutting force model. Second, in order to analyze the elastic deformation of a workpiece, feature points are chosen on the workpiece, and the predicted cutting forces are set as the load on these feature points in ANSYS to conduct a static analysis. Then, the workpiece deformation data is used to build a deformation matrix in order to generate a new tool path that enables volumetric error compensation. This modified tool path is generated as a CL (cutter location) file. Finally, CAM (computer aided manufacturing) software is used to convert the modified CL file into NC code, so milling experiments can be conducted. In this study, the cutting forces during the milling process are measured using a sensory tool holder. To use the cutting force data from a sensory tool holder to do an analysis, data coordinate transformation between the tool and workpiece is necessary.
Moreover, in order to establish a process that can allow users to quickly and easily obtain the compensation tool path necessary to conduct a milling experiment, three main program interfaces are built using MATLAB software. Three programs are used to calculate the cutting constants, to predict the cutting force, and to generate the compensation tool path, respectively. Finally, for demonstration and verification, a thin workpiece machining example was made, including a tool path simulation in NX CAM software and practical machining on a CNC milling machine. The results of the thin workpiece milling experiment proved the approach presented in this study successfully improved machining precision and processing efficiency at the same time.

摘要 I
Extended Abstract III
誌謝 XX
目錄 XXI
表目錄 XXV
圖目錄 XXVI
符號說明 XXXII
第一章 緒論 1
1-1前言 1
1-2 文獻回顧 2
1-2-1工具機之誤差分析與補償 2
1-2-2 薄件加工之誤差分析與補償 4
1-3 研究動機與目的 5
1-4 論文架構 6
第二章 基礎理論 8
2-1 端銑刀切削力模式 8
2-1-1 端銑刀座標系統 8
2-1-2 犁切力的成因與影響 10
2-1-3 局部切削力 12
2-1-4 局部切削力之積分 14
2-1-5 總切削力 16
2-2 端銑刀之切削力常數求法 17
2-2-1 端銑刀平均力模式 17
2-2-2 端銑刀切削力常數 19
2-3 球銑刀切削力模式 21
2-3-1球銑刀座標系統 22
2-3-2局部切削力 23
2-3-3總切削力 28
2-4 加工誤差 29
2-5 有限元素法 30
第三章 研究方法與系統架構 31
3-1 薄工件之體積誤差補償 31
3-2 體積誤差之擬合函數 33
3-3 修正刀具路徑 34
3-4 研究流程 36
3-5 智慧型刀把 37
3-5-1設備及裝置 37
3-5-2量測數據之座標轉換 40
3-5-3刀把座標系統定位 44
3-6 程式介面 47
3-6-1切削常數計算介面 47
3-6-2切削力模擬介面 49
3-6-3 端銑刀與球銑刀切削力模擬與文獻驗證 50
3-6-4補償後之加工路徑建立介面 62
第四章 薄件之體積補償應用實例 65
4-1 薄件實例分析 65
4-1-1 實驗設備介紹 66
4-1-2 切削常數 69
4-1-3 切削常數驗證 70
4-1-4 薄件幾何模型 73
4-1-5 彈性變形之分析與補償 74
4-2 加工精度量測 84
4-2-1 原始加工路徑 84
4-2-2 補償後加工路徑 88
4-3 路徑補償前後結果比較 91
4-3-1 加工誤差改善 91
4-3-2 加工效率改善 93
第五章 結論與未來展望 94
5-1 結論 94
5-2 未來展望 96
參考資料 97
索引 101

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