Title:
EASILY OPENABLE CAN LID MADE OF METAL PLATE OF EXCELLENT OPENABILITY, AND MANUFACTURE THEREOF
Document Type and Number:
Japanese Patent JPH1135036
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To realize a can lid made of a steel plate wherein a can openability and corrosion resistance are ensured by a pressing work for which a sharp blade is not used and a pushing- back work by a method wherein a cross sectional shape which constitutes an opening piece edge part is made a structure wherein at one part of an S-shaped cutting guide groove, one of the peaks of the S-shape is broken. SOLUTION: When a cutting guide groove is formed, top and bottom dies having smooth curved surfaces at locations corresponding with the shape dimensions of an opening piece 2, are used, and a metal plate is press-formed. After forming a thinner part wherein the plate thickness is gradually changed, a pushing-back work is performed, and the press-formed part is formed into an S-shape, and one part of the metal plate at the thinner part is broken. At the time of can opening, the can opening is advanced by a propagation of the breakge from a broken part 6, and even when a steel plate is used as the metal plate, the can openability is improved. The thinning of the plate thickness at the part to be broken only, is performed by adjusting the shape of the press-forming dies. The thickness of a non-broken part after the pushing-back work, is selected in response to the kind of the metal plate such as a steel plate and an aluminum plate, from the viewpoints of the can openability and drop strength.
Inventors:
NISHIDA HIROSHI
ISAKI TERUAKI
MURAKAMI HIDEKUNI
ISAKI TERUAKI
MURAKAMI HIDEKUNI
Application Number:
JP18989597A
Publication Date:
February 09, 1999
Filing Date:
July 15, 1997
Export Citation:
Assignee:
NIPPON STEEL CORP
International Classes:
B65D17/28; B21D51/44; (IPC1-7): B65D17/28; B21D51/44
Attorney, Agent or Firm:
Yu Shiina (1 person outside)