2011 Fiscal Year Final Research Report

Development of Fine Multi-hole Piercing Process by Using Press Indenting and Chemical Etching

Research Project

Project/Area Number	21560127
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Production engineering/Processing studies
Research Institution	Kyushu Institute of Technology
Principal Investigator	HIROTA Kenji 九州工業大学, 大学院・工学研究院, 准教授 (50273256)
Project Period (FY)	2009 – 2011
Keywords	微細穴 / プレス加工 / 塑性加工 / エッチング / 加工精度
Research Abstract	A new micro piercing process was developed ; after a deep indentation is formed on a sheet metal, the other side of the sheet is removed uniformly by chemical etching until the dissolution reaches the tip of indentation. In this study, multi-holes were pierced by the process and the influence of the hole-pitch on the accuracy of the adjacent holes was investigated. Experi-ments were carried out for a 0. 1mm thick copper alloy sheet. By using conical and V-shaped in-denters, circular and rectangular holes having tens of micrometers in size were successfully pro-duced, respectively. The error of thickness reduction by etching was more influential on the dimen-sional accuracy of the hole than that of the indenting depth. The hole shape was distorted when the pitch between holes was below a specific threshold. The threshold pitch for rectangular holes was considerably larger than that for circular holes, which was explained by the metal flow during in-denting.

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