運用噴墨式感測器於切削溫度之偵測

Applying Ink-jet Patterned Sensor in On-line Cutting Temperature Monitoring

張繼文(Chi-Wen Chang)

指導教授 ： 李貫銘

國立臺灣大學/工學院/機械工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10391

摘要

在切削作業中，刀尖溫度之量測方法仍有諸多困難，因為最高溫度發生位置位於刀具與切屑之接觸面，若使用紅外線熱像儀是容易受到切屑或切削液的干擾。若使用熱電偶或是熱敏電阻，亦難以直接到達該溫度面作量測，且必須於刀具做鑽孔加工，增加成本。
為了提高監控系統在經濟上之效益，本研究開發出適用於車削加工之溫度感測器，此感測器採用噴墨式熱敏電阻，擁有相當高之熱敏指標B值，使得溫度量測範圍以及分辨率皆得以提升。另一方面採用噴墨製程，實現感測元件微小化以及陣列量測的可能。不但能夠大幅降低感測器對溫度之反應時間，更可以實現陣列溫度場之量測。為達成在線監控(online monitoring)之目標，本研究使用二維FTCS(forward time central space)有限差分法求解逆向熱傳問題(inverse heat conduction problem, IHCP)。利用噴墨式熱敏電阻量測之溫度與FTCS預測之結果比較，以逼近法推估刀尖平均溫度。
研究結果證實，本論文提出之溫度感測器可對溫度變化做出快速的預測。在後續切屑溫度驗證中，模型預測之表面溫度亦與切削溫度範圍吻合，由此確認本論文提出之溫度感測與預測方法具有相當之準確性。

關鍵字

切削溫度 ； 噴墨式感測器

並列摘要

In cutting, how to measure the tool tip temperature is always an issue. The highest temperature happens at the contact surface between the tool chip and swarfs, which is hard for non-contact methods such as infrared thermal imaging to measure the surface temperature since it is affected by the scattering swarfs and cutting fluid. For conventional contact measuring methods such as thermocouple or thermistor, additional drilling hole is needed to place the sensor in the designated position, which greatly increase the total cost, besides, it is hard to reach the exact contact surface to measure the real contact surface temperature.
To increase the economy effect for cutting process monitoring system, this research proposes a temperature sensor adapt to lathe cutting process. This sensor is an ink-jet-printed thermistor with high thermal sensitive B parameter, which greatly increases the temperature measuring range and resolution. In addition, the ink-jet-printed method realizes the sensor microminiaturization and matrix measuring, which greatly reduced the sensing response time and can measure the temperature distribution matrix.
Meanwhile, to realize the online monitoring capability, this research also proposes a 2-D thermal conduction model with FTCS (Forward Time Central Space) method to solve the inverse heat conduction problem. And by using bisection method between the measured temperature and the 2-D thermal conduction model, the average tip temperature can be solved.
The research result shows that the proposed ink-jet-printed thermistor sensors with 2-D thermal conduction model do provide a fast prediction capability to the temperature variation. And the predicted tip surface temperature lays in the same range with lathe swarfs, which proves the accuracy for the proposed temperature sensing technique from this research.

並列關鍵字

cutting temperature ； ink-jet-printed thermistor

參考文獻

[1] N. Abukhshim, P. Mativenga, and M. Sheikh, "Heat generation and temperature prediction in metal cutting: A review and implications for high speed machining," International Journal of Machine Tools and Manufacture, vol. 46, pp. 782-800, 2006.

[2] D. A. Stephenson, "Assessment of Steady-State Metal Cutting Temperature Models Based on Simultaneous Infrared and Thermocouple Data," Journal of Engineering for Industry, vol. 113, pp. 121-128, 1991.

[3] A. Basti, T. Obikawa, and J. Shinozuka, "Tools with built-in thin film thermocouple sensors for monitoring cutting temperature," International Journal of Machine Tools and Manufacture, vol. 47, pp. 793-798, 2007.

[4] W. Grzesik, "Determination of temperature distribution in the cutting zone using hybrid analytical-FEM technique," International Journal of Machine Tools and Manufacture, vol. 46, pp. 651-658, 2006.

[5] Y. Dogu, E. Aslan, and N. Camuscu, "A numerical model to determine temperature distribution in orthogonal metal cutting," Journal of Materials Processing Technology, vol. 171, pp. 1-9, 2006.