在進行塑膠模具設計時，若要開模的零件為簡易造型的零件，則工程師可以輕易判斷出分模線、分模面及脫模方向，但對於造型複雜的零件，例如運動型頭盔，則因為產品特性之故，有許多倒勾區域及複雜曲面，所以在進行模具設計時，需建立數個能順利脫模的滑塊，且每一個滑塊在製造過程中均需考量工件表面的平順度，此將造成在模具設計過程中，分模線的選擇非常困難。針對此問題，本論文將針對不同類型之運動型頭盔擬定滑塊設計的標準作業流程，以輔助模具設計工程師規劃設計步驟，避免浪費時間於繁瑣的模具反覆修改。在本研究中以運動型頭盔為載具，運用倒勾區域之脫模方向，對頭盔表面作脫模性分析，尋找可脫模和不可脫模之交線，進而劃分分模線範圍，再依脫模順序建立滑塊及公母模仁，最後使用Creo 2.0中的干涉分析功能來驗證滑塊脫模時的干涉情形。本研究以兩個不同型式的運動型頭盔做為應用實例，驗證所提出之模具設計標準作業流程之可行性。

For a plastic mold design, if the molding parts have simple geometry, the engineer can easily determine the parting curves, parting surfaces, and releasing directions. However for complex modeling parts, such as sports helmets, many undercut regions and complex free-form surfaces exist due to the product features, therefore during the process of mold design, it is necessary to create a number of sliders for interference-free mold opening. Besides, in the manufacturing of each slider, the smoothness of the part surface must be considered, thus the choice of parting curves is very difficult in the process of mold design. To solve this problem, this thesis develops standard operating procedures (SOP) for slider design for different types of sports helmets in order to facilitate mold design engineers in the planning and design stage in order to avoid wasting time on tedious and repeated mold modifications. Taking a sports helmet as a case study, this thesis made use of the releasing directions of the undercut regions on the helmet surface for the demoldability analysis to look for the crossover between demoldable and non-demoldable; further divided the range of parting curves; built the sliders, the core and the cavity in accordance with the sequence of mold opening; as well as validated the interference scenario during the release of the sliders by using the function of interference checking in Creo 2.0. Taking two different types of sports helmets as application examples, this study validated the feasibility of the proposed SOP for plastic mold design of sports helmets.

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