Title:
METHOD AND DEVICE OF FORMING EXTRUSION EDGE
Document Type and Number:
Japanese Patent JPS5376967
Kind Code:
A
Abstract:
Method and apparatus for extruding burr holes in a metal sheet, in which a punch with a conical end portion and adjoining cylindrical portion of a diameter greater than the inner burr diameter is passed through the burr. The conical end portion has a half apex angle between 10 DEG and 20 DEG , and the axial length of the cylindrical portion and the coefficient of friction between the cylindrical portion and the burr wall are selected according to a specified relationship.
Inventors:
YOHANESU ARUNORUDASU GERARUDAS
Application Number:
JP15122877A
Publication Date:
July 07, 1978
Filing Date:
December 17, 1977
Export Citation:
Assignee:
PHILIPS NV
International Classes:
B21C37/29; B21D19/08; (IPC1-7): B21D19/00; B21D28/14