Effect of Coil Geometry on Induction Heating for Injection Mold Part

感應加熱線圈之幾何形狀於射出模具之影響性

陳夏宗(Shia-Chung Chen) ； 蔡碧霖(Pi-Lin Tsai) ； 張仁安(Jen-An Chang) ； 范山明(Pham Son Minh)

《中國機械工程學刊》 43卷2期 (2022/04) Pp. 97-106

摘要

In this study, a sample mold plate was used to test an induction heating system with different coil designs. Four coil configurations, parallel, spiral, 3D, and serial coil, were constructed for the induction heating process. The mold surface temperature was heated in 2 s. The temperature at three points and the temperature distribution on the heating surface were then collected to evaluate the effect of the coil geometry on the induction heating process. At the same heating power, the spiral coil has the highest heating rate of 35.5 ℃/s, followed by the 3D coil at 25.5 ℃/s. In addition, the spiral coil creates a ring-shaped high temperature area while the 3D coil creates a rectangular high temperature area. The 3D coil also exhibits better temperature uniformity than the spiral coil, which reduced the temperature difference between 3 points from 41 ℃ (spiral coil) to 23 ℃ (3D coil). Results also show that the heating effect of the parallel and serial coil are not good enough for use in the injection molding process. By using the 3D coil, double sided heating was achieved with positive results. Although the heating rate of the double sided heating is not as high as with single sided heating because of the larger area that must be heated, the temperature difference between three points fell from 23 ℃ to 17.5 ℃ in the experiment when double sided heating was used.

關鍵字

injection molding ； dynamic mold temperature control ； induction heating ； 3D coil ； coil design

並列摘要

本研究中，透過感應加熱系統搭配不同幾何形狀之線圈加熱於模板上，探討不同幾何形狀之加熱效果。本研究建構四種不同的線圈設計，分別為平行式、螺旋式、3D立體式以及串聯式線圈。於2秒的加熱過程中，利用溫度感測器收集模板上三處位置的點溫度數據，以及透過紅外線熱影像儀所拍攝之整體溫度分佈，藉此評估不同幾何形狀於加熱過程中的影響。結果中，於相同的加熱功率下，螺旋線圈之加熱速率最高，可達35.5℃/s，其次為3D線圈之25.5℃/s。此外，螺旋線圈於加熱過程中會產生環形的高溫區域，而3D線圈則產生矩形的高溫區域。但是整體溫度均勻性結果中，3D線圈有較好的表現，3處溫度點的溫差由41℃（螺旋線圈）降低至23℃（3D線圈）。結果還表明了，並聯與串聯線圈的加熱效果，並不適用於射出成型中。通過使用3D線圈，雙面模板之加熱效果取得了良好的成果。雖然加熱效率較單面加熱低，因為整體受加熱的面積變大了，但是使用雙面加熱時，三點的溫度差異由23℃降低至17.5℃。