工具機溫昇熱變形及補償之控制研究

Study in Control of Thermal Errors and Compensation for Machine Tools

張銘雄(Ming-Shiung Chang)

指導教授 ： 康淵

中原大學/工學院/機械工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300680

摘要

由於工具機的高速高精度加工需求，使得因主軸運轉及環境溫度變化所造成的結構熱變形誤差已經成為影響機器加工精度的主要原因。因此，近來CNC工具機的熱變形誤差電腦補償技術逐漸受到重視。
本論文研究主要在發展一套即時熱誤差補償系統，應用於減少綜合加工機的熱變形誤差。為了達到這個目的，首先必須建立一套工具機溫度與熱誤差的精密量測裝置。並將實驗量測結果透過移動平均分析(MA)及自回歸移動平均分析(ARMA)，建立溫度與熱誤差的關係的補償數學模型。此外研究中同時探討比較二種溫度感測器的固定方式與固定位置對補償數學模型強健性的影響。最後為了實機線上補償驗證，發展以單晶片及PC的基礎的補償資訊產生器連結至FANUC 數值控制器，並且利用數值控制器上之機械座標原點偏移功能，達到減少立式綜合加工機熱變形誤差的目的。由實驗結果顯示，16小時主軸變動轉速空切削情況下，即時補償系統可成功地將立式綜合加工機Y、Z軸方向上的熱變形誤差分別由原來的60μm及30μm降低至以±10μm內。

關鍵字

工具機 ； 立式綜合加工機 ； 熱變形 ； 誤差補償 ； 熱漂移

並列摘要

Because the high speed and high precision machining of the machine tools, the structural thermal expansion errors due to the spindle rotation and the variable environment temperature are the main factor that influence the machining accuracy of the machine tools. Hence, the computer compensation techniques for thermal expansion errors of CNC machine tools have received significant attention recently.
In the research described in this paper, a real-time thermal errors compensation system on a vertical machining center was developed to reduce the thermal errors of machine tools. For this purpose, a precision measuring instrument be established to measure temperature variation and thermal errors on machine tools. A mathematical model is then derived, based on the sensed temperature variation and the thermal errors by Moving Average (MA) and Auto-Regression Moving Average (ARMA). A robust compensation modeling approach is also obtained by change the fixation and location of temperature sensors. A single chip and a PC based error compensation scheme has also been developed to connect a FANUC CNC controller for real-time compensation. And shift the zero point of the machine coordinate system to reduce the thermal errors for a vertical machining center. The experimental results show that the technology can successfully reduce the thermal errors from 60 μm to ±10μm for y axis in 16 hours, and from 30 μm to ±10μm for z axis.

並列關鍵字

Thermal shift ； Thermal expansion ； Machine tools ； Vertical machining center ； Error compensation

參考文獻

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