| 研究生: |
陳郁雯 Chen, Yu-Wen |
|---|---|
| 論文名稱: |
智慧型刀把於薄件加工切削力驗證及工件體積誤差補償分析 Cutting Force Validation and Volumetric Errors Compensation of Thin Workpieces with Sensory Tool Holder |
| 指導教授: |
黃聖杰
Hwang, Sheng-Jye |
| 學位類別: |
碩士 Master |
| 系所名稱: |
工學院 - 機械工程學系 Department of Mechanical Engineering |
| 論文出版年: | 2018 |
| 畢業學年度: | 106 |
| 語文別: | 中文 |
| 論文頁數: | 102 |
| 中文關鍵詞: | 薄件 、彈性變形 、體積誤差補償 、智慧型刀把 |
| 外文關鍵詞: | thin workpiece, elastic deformation, volumetric error compensation, sensory tool holder |
| 相關次數: | 點閱:112 下載:3 |
| 分享至: |
| 查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報 |
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.
[1]S. Lin and R. Yang, "Force-based model for tool wear monitoring in face milling," International Journal of Machine Tools and Manufacture, Vol. 35, pp. 1201-1211, 1995.
[2]A. Sarhan, R. Sayed, A. Nassr, and R. El-Zahry, "Interrelationships between cutting force variation and tool wear in end-milling," Journal of Materials Processing Technology, Vol. 109, pp. 229-235, 2001.
[3]R. Ramesh, M. Mannan, and A. Poo, "Error compensation in machine tools—a review: part I: geometric, cutting-force induced and fixture-dependent errors," International Journal of Machine Tools and Manufacture, Vol. 40, pp. 1235-1256, 2000.
[4]P. Andersson, Methodology for Evaluating the Production Accuracy of Machine Tools: Tampereen teknillinen korkeakoulu, 1992.
[5]M. Rahman, J. Heikkala, and K. Lappalainen, "Modeling, measurement and error compensation of multi-axis machine tools. Part I: theory," International Journal of Machine Tools and Manufacture, Vol. 40, pp. 1535-1546, 2000.
[6]A. W. Khan and W. Chen, "A methodology for systematic geometric error compensation in five-axis machine tools," The International Journal of Advanced Manufacturing Technology, Vol. 53, pp. 615-628, 2011.
[7]J.-S. Tsai and C.-L. Liao, "Finite-element modeling of static surface errors in the peripheral milling of thin-walled workpieces," Journal of Materials Processing Technology, Vol. 94, pp. 235-246, 1999.
[8]T. Aijun and L. Zhanqiang, "Deformations of thin-walled plate due to static end milling force," journal of materials processing technology, Vol. 206, pp. 345-351, 2008.
[9]L. Gang, "Study on deformation of titanium thin-walled part in milling process," Journal of materials processing technology, Vol. 209, pp. 2788-2793, 2009.
[10]H. Ning, W. Zhigang, J. Chengyu, and Z. Bing, "Finite element method analysis and control stratagem for machining deformation of thin-walled components," Journal of materials processing technology, Vol. 139, pp. 332-336, 2003.
[11]M. Wan, W. Zhang, G. Qin, and Z. Wang, "Strategies for error prediction and error control in peripheral milling of thin-walled workpiece," International Journal of Machine Tools and Manufacture, Vol. 48, pp. 1366-1374, 2008.
[12]L. C. Huang, Volumetric Errors Analysis and Compensation of Elastic Deformation of Thin Workpiece in Five-Axis Virtual Machining, Master Thesis, Department of Mechanical Engineering, National Cheng Kung University, 2013.
[13]J.-J. J. Wang and C. Zheng, "An analytical force model with shearing and ploughing mechanisms for end milling," International Journal of Machine Tools and Manufacture, Vol. 42, pp. 761-771, 2002.
[14]J.-J. J. Wang, S. Y. Liang, and W. J. Book, "Convolution analysis of milling force pulsation," Journal of Engineering for Industry, Vol. 116, pp. 17-25, 1994.
[15]H. C. Chang, A force model for face and end milling with side and bottom plowing effects, Master Thesis, Department of Mechanical Engineering, National Cheng Kung University, 2001.
[16]W. Endres, R. DeVor, and S. Kapoor, "A dual-mechanism approach to the prediction of machining forces, part 1: model development," Journal of engineering for industry, Vol. 117, pp. 526-533, 1995.
[17]W. Endres, R. DeVor, and S. Kapoor, "A dual-mechanism approach to the prediction of machining forces, part 2: calibration and validation," Journal of Engineering for Industry, Vol. 117, pp. 534-541, 1995.
[18]M. Martellotti, "An analysis of the milling process," Trans ASME, Vol. 63, p. 677, 1941.
[19]I. Yellowley, "Observations on the mean values of forces, torque and specific power in the peripheral milling process," International Journal of Machine Tool Design and Research, Vol. 25, pp. 337-346, 1985.
[20]J.-J. Wang and C. Zheng, "Identification of shearing and ploughing cutting constants from average forces in ball-end milling," International Journal of Machine Tools and Manufacture, Vol. 42, pp. 695-705, 2002.
[21]C. Y. Huang, Force Model and Stability Analysis for Step-Over Cutting in Ball-End Mill, Master Thesis, Department of Mechanical Engineering, National Cheng Kung University, 2001.
[22]M. Saeed, Finite element analysis: theory and application with ANSYS, New Jersey, Prentice Hall, 2003.
[23]P. Lee and Y. Altintas, "Prediction of ball-end milling forces from orthogonal cutting data," International Journal of Machine Tools and Manufacture, Vol. 36, pp. 1059-1072, 1996.