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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).
南台科技大學 精密製造實驗室，102年8月8日