Improvement of Wire Transport System in Wire Electrical Discharge Machining Machine
| Autor: | Chen, Guanbin, 陳冠彬 |
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| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 The improvements of wire transport system on machining precision of wire electrical discharge machining (W-EDM) are investigated. The impedance-based string vibration theory is employed to analyze the dynamic behavior of the wire electrode coupled with a damper. The optimal damping coefficient is obtained through exercising the developed theory. The active wire transport apparatus and damped vibration absorber are integrated with the commercial wire transport system to test their performances on the wire tension variation, surface roughness, corner error and straightness. The wire tension variation can be reduced from 127 gf to 84 gf after mounting active wire transport apparatus and the variation frequency is also significantly increased. After mounting both damped vibration absorber and active wire feed apparatus, the high frequency variation can be eliminated and the wire tension variation can be further reduced to 47 gf. A 50 mm thickness, SKD11 tool steel is used to test the influences on the machining precision. Results show that the surface roughness and straightness and corner error are not significantly improved when mounting either one device on the WEDM machine. After mounting both devices, the surface roughness, 30°corner error, and straightness can be reduced from Ra 3.5 μm to 2.7 μm, 48 μm to 29 μm and 28.4 μm to23.8 μm, respectively. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
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