Dieless punching of ultrasmall-diameter holes
Dieless punching of ultrasmall-diameter holes
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超小直径孔的无模冲裁
DOI：
10.1016/j.precisioneng.2022.07.011
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Keishi Yamaguchi
中科院分区：
文献类型：
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作者：
Kai Egashira;Hayata Hamafuji;Shinya Araki;Keishi Yamaguchi
由于用传统的冲压方法很难冲压出超小直径的孔，因此尝试了无模冲压。通过拆模，解决了超小直径模孔冲裁和模架装配困难的问题。用胶带代替模具支撑工件。使用通过电火花加工制造的烧结碳化钨小直径冲头对不锈钢板进行冲压。结果，使用10 μ m直径的冲头在5 μ m厚的片材上成功地冲压出直径为8.5 μ m的孔。还使用直径为6 μ m的冲头在3 μ m厚的片材上冲出直径小于6 μm的孔。此外，使用测力传感器测量冲头载荷的演变，并且冲头载荷被示出为当冲头穿透工件时达到正峰值。研究了冲裁条件与冲裁特性之间的关系，结果表明，当冲裁速度为50 μm/s时，直径为10 μ m的冲裁模要冲裁5 μ m厚的工件，冲裁行程至少为30 μm。此外，最大冲压载荷随着冲压进给速度的增加而减小。当冲头旋转时，孔直径增加，这可能是由于冲头外周表面的切割作用。切割动作促进冲压穿透，从而减少冲压负荷。超声波振荡也通过在冲头轴向方向上振荡工件来使用。冲头载荷大大降低，表明即使在工件而不是冲头振动时，超声波振动也是有效的。
The dieless punching of ultrasmall-diameter holes was attempted because it is difficult to punch such holes by conventional punching methods. Removing the die made it possible to solve the problem of difficulty in piercing an ultrasmall-diameter die hole and assembling a die set. The workpiece was backed up with adhesive tape instead of the die. Stainless-steel sheets were punched using cemented tungsten carbide small-diameter punches fabricated by electrical discharge machining. As a result, an 8.5-μm-diameter hole was successfully punched in a 5-μm-thick sheet using a 10-μm-diameter punch. A hole with a diameter smaller than 6 μm was also punched in a 3-μm-thick sheet using a 6-μm-diameter punch. Furthermore, the punch load evolution was measured using a load cell, and the punch load was shown to reach a positive peak when the punch penetrated the workpiece. An investigation into the relationships between punching conditions and punching characteristics showed that the punch stroke must be at least 30 μm for a 10-μm-diameter punch to penetrate a 5-μm-thick workpiece at a punch feed speed of 50 μm/s. In addition, the maximum punch load decreased with increasing punch feed speed. When the punch was rotated, the hole diameter increased, likely because of the cutting action of the punch peripheral surface. The cutting action facilitated punch penetration, resulting in a reduced punch load. Ultrasonic oscillation was also employed by oscillating the workpiece in the punch axial direction. The punch load was considerably reduced, demonstrating that ultrasonic oscillation is effective even when the workpiece is oscillated instead of the punch.