博士 / 國立臺北科技大學 / 機電學院機電科技博士班 / 107 / This study changed D-type submarine gate angles to achieve superior degating results and produce less degating residue. The goal was to decrease the force-bearing area given an identical ejector force, thereby increasing the degating stress. A tensile test was performed to identify brittle plastic materials, in which degating stress was calculated using the theoretical formulas typically used for calculating brittle material’s stress. According to the calculations, flipping the gate angles created higher degating stress. Subsequently, a computer-assisted engineering software called ANSYS Workbench was utilized to calculate stress created during degating. The results revealed that the higher the flip angle was, the greater the stress became, and that the higher the wedge angle was, the lower the maximum principal stress became. Next, a fatigue life test was conducted; the results indicated that flip angle exhibited a minimal effect on fatigue life. Then, Autodesk Moldflow was used to perform filling and packing analyses, where the results showed that the least filling stress was achieved at a flip angle of 60°; such flip angle also produced a relatively small air trap effect. On the basis of these findings, the D-type submarine gate with a flip angle of 60° was compared with the D-type submarine gate with a flip angle of 0° during an open-die verification experiment.
The verification experiment showed that when the fixed number sampling method was adopted, gate residue was observed in the 1000th mode of the D-type submarine gate with a flip angle of 0°, whereas no gate residue was observed by the 3500th mode of the D-type submarine gate with a flip angle of 60°. When the random sampling method was adopted, more than 50% of D-type submarine gates with a flip angle of 0° had gate residue (note that 32% of them exceeded the requirement of 0.05 mm), whereas only 12% of D-type submarine gates with a flip angle of 60° had gate residue. These results confirm that flipped D-type submarine gates demonstrate superior degating performance than traditional D-type submarine gates do, and that they can effectively reduce degating residue.
| Identifer | oai:union.ndltd.org:TW/107TIT05657001 |
| Date | January 2018 |
| Creators | Iao, Hong-wai, 尤鴻威 |
| Contributors | 陸元平 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 123 |
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