Title:
COUNTERSUNK HOLE FORMING METHOD AND PRESS MACHINE
Document Type and Number:
Japanese Patent JP2018089632
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a countersunk hole forming method which enables a countersunk hole to precisely be formed in a vicinity of the end part of a tabular workpiece and a press machine.SOLUTION: A method of forming a countersunk hole 30 where a first position P1, a vicinity of the end part Wa of a tabular workpiece W, is the center of a through hole 31, includes: a lower hole forming step of forming a lower hole 10, which is centered on a second position P2 off the end part Wa of the tabular workpiece W from a first distance d1 and has an area smaller than the area of the through hole 31; a countersunk molding step of countersunk processing, to a region including the lower hole 10, centered on the first position P1 or a third position P3 in a vicinity of the first position P1 to form a flat part 21 in a taper part 32 or a part of the region surrounded by this taper part 32; and a through hole forming step of forming a through hole 31, to a region including the flat part 21, centered on the first position P1.SELECTED DRAWING: Figure 1
Inventors:
AOI MASAMICHI
Application Number:
JP2016232391A
Publication Date:
June 14, 2018
Filing Date:
November 30, 2016
Export Citation:
Assignee:
MURATA MACHINERY LTD
International Classes:
B21D28/24; B21D19/00; B21D22/02; B23K26/382
Attorney, Agent or Firm:
Kazuya Nishi
Tomihiko Isono
Tomihiko Isono
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