氣體式快速模具表面動態溫控方法 建置與分析之研究

Investigation on the Establishment and Analyses of Rapid Mold Surface Temperature Control Using Gas-Assisted Heating

張仁安(Jen-An Chang)

指導教授 ： 陳夏宗

中原大學/工學院/機械工程學系/博士(2008年)

https://doi.org/10.6840/CYCU.2008.00010

摘要

有別於傳統的模具溫度控制方法，新型的『動態模具溫度控制技術』於充填階段維持高模溫及充填結束後快速冷卻降溫以取出成型品之特性，可成功解決大部份傳統射出成型品的問題，一次達成高等級外觀面需求及精密射出成型，具有高度發展潛力與重要性。
本研究目的在建置一新型氣體式模具快速加熱系統以及電腦模擬溫控分析技術，利用高溫氣體快速通過模具表面進行瞬間加熱之溫控實驗、模擬以及效益評估。首先設計外部式氣體加熱與感應式加熱比較實驗，確認介面熱阻設計與影響。其次建置內部式氣體加熱基礎實驗，將高流量熱氣導入實驗模具內以進行模具表面動態溫控。同時利用CFD-ACE軟體進行流體-固體耦合分析並與實驗比對，藉以尋找可信之對流熱傳係數h值，提升分析可信度。
研究結果顯示，搭配介面熱阻設計可有效提升氣體加熱速度。將氣體導入模具內部加熱實驗結果，中央進氣（垂直模仁）搭配熱阻隔方式，升溫速度13.3 ℃/s；無搭配熱阻隔升溫速度可達8.5 ℃/s。側邊進氣（平行模仁）搭配熱阻隔升溫速度可達6.3 ℃/s，無搭配熱阻隔升溫速度可達3.8 ℃/s。高速流動的熱氣才能有效提升加熱效率；垂直模面的衝擊式加熱能有較高的加熱速度，並可以得到局部加熱之結果。若氣體平行於模面加熱方式要能夠成功可行，提高氣體流速方式具有較明顯結果。流體-固體耦合分析結果與實驗分析趨勢符合，已達成有效建立可信賴之氣體輔助加熱分析技術。
從本研究中，可以充分瞭解氣體式加熱製程所需的重要控制參數與應用方式，並建立具體實驗數據與氣體加熱特性掌握，相關研究成果可提供研究人員或相關業者在應用氣體加熱模具之參考準則。

關鍵字

流體-固體耦合分析 ； 氣體式加熱 ； 動態模具溫度控制

並列摘要

High mold temperature provided great contributions to injection molded parts. In conventional, the mold temperature variation entails a long duration because a much longer time is needed to rise whole mold base of the heating/cooling medium (oil or water). Thus, the cycle time will be longer than using a variable mold surface heating technology. Consequently, in this work, a new concept of gas-assisted mold heating was used for rapid mold surface heating and reduced cycle time. The first stage will establish a forced air convection heating system, and design the parameter of process for the effect of mold temperature. The next, suitable thermal resistance design combine with difference type of gas entrance gate to increase heating speed. Finally, heating experiment to find out correlative operation parameters and implement CFD-ACE analysis for fluid-solid couple heat transfer analysis for comparing the experiments results.
As a result, the mold surface temperature can be heated efficiently with a thermal resistance design. In the direct gate design, with or without thermal resistance, the heating speed is 13.3 ℃/s and 8.5 ℃/s, respectively. In the horizontal gate design, with or without thermal resistance, the heating speed is 6.3 ℃/s and 3.8 ℃/s, respectively. Direct gate design case can get the best heating efficiency in local area. The higher air speed can improve the heating speed especially on the horizontal gate design case. The result of convection heat transfer analysis can verify the results of the experiment.
In summary, we can realize the important parameters and design rule of the applications for force convection air heating. The selection of air heating as the method of mold surface temperature control delivering energy represented the simplest and accepted method.

並列關鍵字

Gas-assisted heating ； Dynamic mold temperature control

參考文獻

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