南台科技大學 精密製造實驗室， 102 年 8 月 8 日 班級 : 碩研機械一甲 姓名 : 鄧文斌 指導老師 : 曾信智

南台科技大學 精密製造實驗室， 102 年 8 月 8 日 Introduction─ Conventional approach in mold design for injection molding is based on allowances for post mold shrinkage of the part. Experienced designers account for possible warping by allowing for ‘‘windage’’ in tool design. Conventional practice also involves an iteration of modification on the existing mold until the molded part is within specification as shown in Fig. 1. Such procedure results in long and expensive product development time.

南台科技大學 精密製造實驗室， 102 年 8 月 8 日 In order to cut product development, cycle time and cost, mold flow simulation software like Mold Plastic Insight (MPI) is used to predict the interaction between product design and mold (Fig. 2). The need for such analysis becomes more critical since the material used involves fiber reinforcement. During injection molding,fiber orientation occur inevitably causing anisotropy that affects the final parts properties and characteristics. However, by predicting beforehand, the anisotropic can be utilized to make the composite part lighter, stiffer, stronger and more reliable than the uncontrolled composites.

南台科技大學 精密製造實驗室， 102 年 8 月 8 日 Fig. 3 indicates a similar trend clearly exists between published experimental results and the predicted results of the fiber orientation pattern in injection molded polycarbonate disc.

南台科技大學 精密製造實驗室， 102 年 8 月 8 日 Methodology─ Currently, the existing pedal box system used by a Malaysian car manufacturer has been made mainly from metal except for accelerator pedal, where it is made from polyamide composite for one of its car. The design of the accelerator pedal is observed in terms of weight, wall thickness, and profile shape and ribbing pattern. These observations helped to initiate some ideas in this research before converting the current steel clutch pedal design into a polyamide composite. The design of the steel clutch pedal for a Malaysian car is shown in Fig. 4.

南台科技大學 精密製造實驗室， 102 年 8 月 8 日 The outline of the simulation program for MPI is described in Fig. 5.

南台科技大學 精密製造實驗室， 102 年 8 月 8 日 In this research, MPI is used to study the effects of gating number for both V and X ribbing for profile clutch pedal (Fig. 6).