Effect of Electrode Shape on High Aspect Ratio Deep Hole Drilling by EDM
Effect of Electrode Shape on High Aspect Ratio Deep Hole Drilling by EDM
复制标题
电极形状对电火花高深宽比深孔钻削的影响
DOI：
10.1016/j.procir.2022.09.156
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
TANI Takayuki
中科院分区：
文献类型：
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作者：
HIRAO Atsutoshi;GOTOH Hiromitsu;TANI Takayuki
一般来说，随着加工深度的增加，放电加工（EDM）的加工速度逐渐减慢。特别是，当长径比超过3(L/D＝3)时，加工速度变得显着停滞。这是因为电火花加工产生的加工碎片和聚结气泡介入工作间隙之间，具有显着的影响。长宽比越高（L/D>5），孔底部到顶部的距离越长。因此，很难有效排出孔底产生的加工碎屑和聚结气泡。如果可以将它们移除，则可以进行更深的钻孔。在本研究中，我们研究了工具电极形状对电火花深孔钻削的影响。我们开发了搅拌器形状的电极。与圆棒电极相比，搅拌器形状的电极能够加工大约3.5倍的深度。我们还开发了使用 EDM 方法进行深孔钻削的观察系统。使用观察系统从侧面观察加工碎片和合并的气泡。结果，证实当使用圆棒电极时，工作间隙之间的介电工作流体变黑。这是因为加工碎屑没有从孔的顶部清除，而残留在工作间隙之间的侧面。因此，电极和工件经常短路，Z轴升高。此外，我们制作了哑铃形电极并将其用于电火花加工。通过使用该电极，可以去除EDM产生的气泡。结果，实现了高深孔比的深孔加工。
In general, as the machining depth increases, the machining speed gradually slows down by electric discharge machining (EDM). In particular, when the aspect ratio exceeds 3 (L/D=3), the machining speed becomes significantly stagnant. This is because the machining debris and coalesced bubbles by EDM, which intervene between the working gaps, have a significant effect. The higher the aspect ratio (L/D>5), the longer the distance from the bottom to the top of the hole. Therefore, it is difficult to effectively discharge the machining debris and coalesced bubbles generated at the bottom of the hole. If they can be removed, deeper hole drilling can be performed. In this study, we investigated the effect of the tool electrode shape on deep-hole drilling using EDM. We developed a stirrer-shaped electrode. Compared with the round bar electrode, the stirrer-shaped electrode was able to machine approximately 3.5 times deeper. We have also developed an observation system for deep-hole drilling using the EDM method. Machining debris and coalesced bubbles were observed from a lateral view using the observation system. As a result, it was confirmed that the dielectric working fluid between the working gap turned black when the round bar electrode was used. This is because the machining debris was not removed from the top of the hole and remained at the side between the working gap. Therefore, the electrode and workpiece were frequently short-circuited, and the Z-axis was raised. Further, we made a dumbbell-shaped electrode and used it for EDM. By using this electrode, the bubbles generated by EDM were removed. As a result, deep hole drilling with a high aspect ratio was achieved.