The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 1998
Filed:
Jun. 27, 1996
Masahiko Mitsubayashi, Nagoya, JP;
Masazumi Ohnishi, Toyota, JP;
Noritaka Miyamoto, Toyota, JP;
Shinobu Ishida, Toyota, JP;
Shinji Kawasaki, Toyota, JP;
Shoichiro Nitta, Aichi-ken, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A method of corrugating a metallic pipe which achieves an increase in the limit of tube expansion ratios. First, a heated part is formed by heating a local part of an outer periphery of a pipe in a circumferential direction by a high frequency coil. Next, the heated part is located within a forming surface of a forming die, and an axial compressive stress is applied to the pipe. Thus, the heated part is expanded while restricted by the forming surface. Therefore, even when the axial length of the heated part is increased, formability is stabilized and the tube expansion ratio can be raised.