臺灣博碩士論文加值系統

本研究探討一國產三軸立式綜合加工機的熱變位特性。首先對於三軸立式加工機在不同的轉速下，探討機台內的熱源影響整機結構的溫升及熱變形。在實驗部分，於機台上設置多個關鍵溫度點量測，同時使用非接觸式渦電流位移感測計得到即時的位移。在模擬方面，透過實驗得到的溫度及位移修正模擬分析設定的熱源及邊界條件，進行熱、流、固多重物理耦合，建立機台的熱變位模型，可用以分析預測運轉時溫度及熱變形之間的關係。接著使用散熱風扇改變主軸頭板金內部流場，提高對流散熱的效果，期望使整體機台溫度降低，並搭配適應式熱平衡技術以電熱片改變主軸頭結構溫度分佈，修正熱位移，進而改善加工精度。由本實驗室先前的同機型三軸立式綜合加工機研究結果，明確指出主軸頭上方兩側肋板的溫度分佈對於切削端點的偏傾有關鍵的影響，因此使用最佳化軟體分析電熱片於肋板上的最佳設置位置，以有效控制調節肋板溫度分佈。延續前述結果，搭配本研究所進一步修正改良的熱變形模型，分析得到在不同轉速下此工具機的溫度分佈情形，並以實驗進行驗證，建立出一套適應不同轉速所對應的電熱片加熱功率。機台在持續運轉的狀況下，可經由外部系統控制電熱片的發熱功率，並且進行即時的溫度與位移量測以監控機台狀況。根據實驗所獲得之數據，透過MATLAB進行機台量測點溫度變化與切削端點熱變位的相關性分析，建立電熱片調節機台溫度分佈的控制模型，同時評估最佳化軟體計算出的電熱片位置是否適當。在機台結構不需變更及節能的情況下，得以達到即時修正切削點熱變位的效果，特別是可以有效使加工端點偏傾情況得以改善。

This study investigated the thermal displacement characteristics of a domestic three-axis vertical machining center. First, the machining center was operated at different rotational speeds to explore the temperature variation and the thermal deformation of the structure. Based on the experimental measurements, a multi-physics simulation model was constructed, modified and validated. This model was then used to predict the thermal deformation, as well as to evaluate the critical positions of temperature monitoring and control. Moreover, a cooling fan was used to enhance the convective heat transfer of the spindle head. This study further proposed an adaptive thermal balance technology to manage the temperature distribution of the spindle head structure, mitigating its thermal displacement, and thus improving the machining accuracy. Previous studies to the same three-axis vertical machining center that were carried out in our group clearly pointed out that the temperature distribution of the ribs on the spindle head have significant influence to the thermal displacement, especially thermal bending. The optimal locations on the ribs for heaters to adjust the temperature distribution were determined by using optimization software. Experiments were conducted to verify the effects of the heaters at a variety of spindle speed. In addition, a correlation analysis to the temperature and thermal displacement of the cutting point was carried out. With the proposed adaptive thermal balance technology it has been shown that the thermal error of the machine tool can be effectively reduced without changing the structural design of the machine.

中文摘要 i
Abstract ii
目錄 iii
圖目錄 v
表目錄 viii
第1章 緒論 1
1.1 前言 1
1.2 文獻回顧 2
1.3 研究目的與動機 5
第2章 理論簡介 7
2.1 ANSYS運算理論 7
2.1.1 能量方程式 7
2.1.2 連續方程式 8
2.1.3 動量方程式 8
2.2 熱流耦合能量方程式 9
2.3 熱彈性力學方程式 9
2.4 線性迴歸分析 10
第3章 數值模擬及最佳化分析 12
3.1 數值分析 12
3.2 模擬流程 12
3.3 物理模型 14
3.4 邊界條件 15
3.4.1 馬達熱源 15
3.4.2 軸承熱源 16
3.4.3 皮帶輪熱源 19
3.4.4 自然對流邊界 20
3.4.5 強制對流邊界 21
3.5 網格收斂性 22
3.6 最佳化分析系統 25
3.6.1 最佳化流程 25
3.6.2 最佳化設定 27
第4章 實驗驗證 29
4.1 實驗架構 29
4.1.1 溫度量測系統 29
4.1.2 位移量測系統 30
4.1.3 適應式熱平衡技術 31
4.2 實驗流程規劃 32
第5章 結果與討論 35
5.1 模擬結果 35
5.2 實驗結果 44
5.2.1 主軸9000rpm實驗結果 45
5.2.2 主軸6000rpm實驗結果 51
5.2.3 主軸3000rpm實驗結果 56
5.3 實驗參數分析 61
第6章 結論與建議 65
Reference 67

[1]J. Bryan, "International status of thermal error research (1990)," CIRP Annals-Manufacturing Technology, vol. 39, pp. 645-656, 1990.
[2]J. Mayr, J. Jedrzejewski, E. Uhlmann, M. Alkan Donmez, W. Knapp, F. Härtig, et al., "Thermal issues in machine tools," CIRP Annals - Manufacturing Technology, vol. 61, pp. 771-791, // 2012.
[3]NSK, "Super Precision Bearings," 2006.
[4]T. A. Harris and M. N. Kotzalas, Essential concepts of bearing technology: CRC press, 2006.
[5]J. Takabi and M. M. Khonsari, "Experimental testing and thermal analysis of ball bearings," Tribology International, vol. 60, pp. 93-103, 4// 2013.
[6]T. Maier and M. F. Zaeh, "Modeling of the Thermomechanical Process Effects on Machine Tool Structures," Procedia CIRP, vol. 4, pp. 73-78, // 2012.
[7]Z. Haitao, Y. Jianguo, and S. Jinhua, "Simulation of thermal behavior of a CNC machine tool spindle," International Journal of Machine Tools and Manufacture, vol. 47, pp. 1003-1010, 5// 2007.
[8]E. Uhlmann and J. Hu, "Thermal Modelling of a High Speed Motor Spindle," Procedia CIRP, vol. 1, pp. 313-318, // 2012.
[9]M. Weck, P. McKeown, R. Bonse, and U. Herbst, "Reduction and Compensation of Thermal Errors in Machine Tools," CIRP Annals - Manufacturing Technology, vol. 44, pp. 589-598, // 1995.
[10]E. Miao, Y. Liu, H. Liu, Z. Gao, and W. Li, "Study on the effects of changes in temperature-sensitive points on thermal error compensation model for CNC machine tool," International Journal of Machine Tools and Manufacture, vol. 97, pp. 50-59, 10// 2015.
[11]J. Jędrzejewski, W. Kwaśny, Z. Kowal, and Z. Winiarski, "Development of the modelling and numerical simulation of the thermal properties of machine tools," Journal of Machine Engineering, vol. 14, pp. 5--20, 2014.
[12]J. Vyroubal, "Compensation of machine tool thermal deformation in spindle axis direction based on decomposition method," Precision Engineering, vol. 36, pp. 121-127, 1// 2012.
[13]J. Huang, Z. Zhou, M. Liu, E. Zhang, M. Chen, D. T. Pham, et al., "Real-time measurement of temperature field in heavy-duty machine tools using fiber Bragg grating sensors and analysis of thermal shift errors," Mechatronics, vol. 31, pp. 16-21, 10// 2015.
[14]I. O. f. Standardization, "Test Code for Machine Tools – Part 3: Determination of Thermal Effects, in: ISO 230-3", ed. Geneva: International Organization for Standardization, 2007.
[15]N. N. Verma and S. Mazumder, "Extraction of thermal contact conductance of metal–metal contacts from scale-resolved direct numerical simulation," International Journal of Heat and Mass Transfer, vol. 94, pp. 164-173, 3// 2016.
[16]J. Jędrzejewski, "Effect of the thermal contact resistance on thermal behaviour of the spindle radial bearings," International Journal of Machine Tools and Manufacture, vol. 28, pp. 409-416, 1988.
[17]K. Nakajima, "Thermal contact resistance between balls and rings of a bearing under axial, radial, and combined loads," Journal of thermophysics and heat transfer, vol. 9, pp. 88-95, 1995.
[18]J.-S. Chen and W.-Y. Hsu, "Characterizations and models for the thermal growth of a motorized high speed spindle," International Journal of Machine Tools and Manufacture, vol. 43, pp. 1163-1170, 9// 2003.
[19]R. Ramesh, M. Mannan, and A. Poo, "Thermal error measurement and modelling in machine tools.: Part I. Influence of varying operating conditions," International Journal of Machine Tools and Manufacture, vol. 43, pp. 391-404, 2003.
[20]J. Mayr, M. Ess, S. Weikert, and K. Wegener, "Simulation and prediction of the thermally induced deformations of machine tools caused by moving linear axis using the FDEM simulation approach," in Proceedings ASPE 2008 Annual Meeting, 2008.
[21]J. Mayr, S. Weikert, and K. Wegener, "Comparing the thermo-mechanical-behavior of machine tool frame designs using a FDMFEA simulation approach," in Proceedings ASPE annual meeting, 2007, pp. 17-20.
[22]T. J. Ko, T.-w. Gim, and J.-y. Ha, "Particular behavior of spindle thermal deformation by thermal bending," International Journal of Machine Tools and Manufacture, vol. 43, pp. 17-23, 1// 2003.
[23]J. Jędrzejewski and W. Kwaśny, "Study on reducing energy consumption in manufacturing systems," Journal of Machine Engineering, vol. 11, 2011.
[24]C. Brecher, S. Bäumler, D. Jasper, and J. Triebs, "Energy efficient cooling systems for machine tools," in Leveraging Technology for a Sustainable World, ed: Springer, 2012, pp. 239-244.
[25]OKUMA. (2002). Thermo-friendly concept helps cnc machines take the heat.
[26]P.-C. Tseng and J.-L. Ho, "A study of high-precision CNC lathe thermal errors and compensation," The International Journal of Advanced Manufacturing Technology, vol. 19, pp. 850-858, 2002.
[27]ANSYS, "ANSYS Fluent Theory Guide," 2013.
[28]T. L. Bergman and F. P. Incropera, Introduction to heat transfer: John Wiley & Sons, 2011.
[29]費興泰, 機械熱變形理論及應用: 國防工業出版社, 2009.
[30]S. Chatterjee and A. S. Hadi, "Influential observations, high leverage points, and outliers in linear regression," Statistical Science, pp. 379-393, 1986.
[31]S. H. Brown, "Multiple linear regression analysis: a matrix approach with MATLAB," Alabama Journal of Mathematics, vol. 34, pp. 1-3, 2009.
[32]A. Ugural, Mechanical design: an integrated approach: McGraw-Hill Science/Engineering/Math, 2003.
[33]Fanuc, " Large spindle motor αi series," 2008.
[34]C.-Y. Chung and J. M. Mansour, "Determination of poroelastic properties of cartilage using constrained optimization coupled with finite element analysis," Journal of the mechanical behavior of biomedical materials, vol. 42, pp. 10-18, 2015.
[35]S.-Y. Chen, "Gradient-based structural and CFD global shape optimization with smartDO and the response smoothing technology," in Proceedings of the 7th World Congress of Structural and Multidisciplinary Optimization (WCSMO7), COEX Seoul, Korea, 2007, pp. 1-2.