| 摘要: | 積層製造技術是一種可快速製作具複雜外型產品的技術。在眾多積層製造技術中，熔融沉積成型(Fused Deposition Modeling, FDM)為較常見的方法之一。一直以來，FDM技術有兩個主要缺點：表面品質不佳與製造效率低落。影響FDM技術之製造效率與表面品質的因素主要有三：層與層堆疊方向、切層方式以及路徑生成與規劃，其中路徑之生成是更是FDM技術的基礎。一個完整沉積路徑包含有：垂直殼、水平殼、內部填充以及外部支撐等。而本研究將使用影像處理方式，針對各種基本沉積路徑，提出有效提升製造效率之路徑規劃。
另外，本研究考慮到客製化且一次性的應用之成品，使用完畢即丟棄，在強度需求較低的情況下，使用傳統的內部填充方式：以特定圖形進行模型內部等比例的填充，既耗時又不符合效益，並非是最理想的設計。倘若要以最短時間製造FDM模型，可將內部填充比例設定為0%，使其成為一中空物件。但由於移除內部填充路徑後，部份的沉積路徑下無足夠的支撐附著點，使模形表面產生孔洞。為達到兼顧效率與品質，本研究捨棄傳統內部填充方式，提出兩種內部支撐結構：柱狀結構內部支撐、分支結構內部支撐。此內部支撐僅在懸空特徵使用內部支撐結構，使模型懸空特徵下擁有足夠的附著點，讓材料可以成功的逐漸向上疊加，形成一個完整的實體模型。
本研究以五個範例來驗證本研究所發展的路徑規劃方式與內部支撐路徑生成演算法。在維持相同的表面品質下，結果發現與傳統內部填充方式相比，本研究之內部填充製造時間可減少約6%至16%；柱狀結構內部支撐製造時間可減少約19%至36%；分支結構內部支撐製造時間可減少約34%至54%，證明本方法可有效提高FDM技術的製造效率。
;Additive manufacturing is a technology that can fabricate products with complex shape rapidly. Fused Deposition Modeling (FDM) is one of the commonly used manner in additive manufacturing field. However, FDM has two major disadvantages: poor surface quality and low manufacturing efficiency. Three factors that may influence these disadvantages: build orientation, slicing methods, and path generation and planning. Among these factors, the path generation is the key of FDM. The FDM paths are included vertical shell, horizontal shell, infill and support. This study will purpose a path planning method which can improve manufacturing efficiency via image processing, including all FDM paths.
In addition, this study takes into account the customized and one-time application which is discarded after use. In the case of lower intensity requirements, the use of traditional infll method, a specific pattern with specific infill ratio, is time-consuming and not in the best interest. It is not the best design. In order to get a FDM model as fast as possible, setting the infill ratio to 0% to make a hollow model is a triable strategy. However, due to the removal of the infill path, some of the deposition path may lack support structure and produce cavities on the surface of FDM model. In order to consider both manufacturing efficiency and model quality simultaneously, this study abandoned the traditional infill method and develops two path generation algorithm of inner support for supporting the near dangling features, including pillar-type inner support and branch-type inner support. With inner support structures, there are enough support points to sustain the deposition path on the top, so that the material can successfully stack from bottom to up, layer by layer, and generate a complete solid model.
This study will demonstrate the concept of the path planning and inner support by five cases to verify the result. Comparing with traditional infill method, the result shows that our proposed path planning method improves the 6-16% manufacturing efficiency, pillar-type inner support method improves the 19-36% manufacturing efficiency and branch-type inner support improves the 34-54% manufacturing efficiency. It is proved that this method can effectively improve the manufacturing efficiency of FDM technology. |
