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:
Jun. 09, 1992
Filed:
Feb. 19, 1991
Naoyoshi Sutou, Takasaki, JP;
Toshiharu Shinmura, Takasaki, JP;
Sanden Corporation, Gunma, JP;
Abstract
A method for manufacturing a header pipe of a heat exchanger wherein a planar raw plate is bent to have a U-shaped cross section in a first bending step. Connection holes to which heat exchanger tubes are to be connected are opened directly on the curved portion of the U-shaped raw plate formed by the first bending step. Thereafter, the side portions of the U-shaped raw plate are bent inward to abut their terminal ends to each other. Since the connection holes are formed directly on the curved portion of the raw plate, the size and shape of a punch for opening the connection holes may be set to a size and shape corresponding to the size and shape of the end portions of the heat exchanger tubes. Thus, the desired connection holes can be formed easily and precisely. Even if a deformation occurs on the side portions of the U-shaped raw plate in the connection hole opening step, such a deformation can be corrected in a second bending step. Since only the side portions of the raw plate are bent in the second bending step and not the side portion of the raw plate having the connection holes, the connection holes which have been already formed are not distorted. Therefore, the desired connection holes can be formed with high accuracy.