Method of making a tube for a heat exchanger

(19)

(11)

EP 1 179 719 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	20.03.2002 Bulletin 2002/12

(43)	Date of publication A2:
	13.02.2002 Bulletin 2002/07

(21)	Application number: 01117658.3

(22)	Date of filing: 25.07.2001

(51)	International Patent Classification (IPC)⁷: F28D 1/03, F28F 3/04, B21C 37/08, B21C 37/15

(84)	Designated Contracting States:
	AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
	Designated Extension States:
	AL LT LV MK RO SI

(30)

Priority:

08.08.2000 US 634037

(71)	Applicant: Modine Manufacturing Company
	Racine Wisconsin 53403 (US)

(72)	Inventors:
	Heyse, Richard P. Racine, Wisconsin 53406 (US) Eggert, Jeffrey F. Kenosha, Wisconsin 53142 (US) Fox, Richard A. Racine, Wisconsin 53406 (US) Kaat, Ronald J. Racine, Wisconsin 53404 (US)

(74)	Representative: Heselberger, Johannes
	Bardehle, Pagenberg, Dost, Altenburg, Geissler, Isenbruck, Postfach 86 06 20 81633 München 81633 München (DE)

(54)	Method of making a tube for a heat exchanger

(57) Method for manufacturing dimpled, flattened tubes for heat exchangers including the steps of:

a) providing an elongated strip of aluminum based material (22) having opposed edges (24,26) and a braze alloy on only one side thereof;
b) forming dimples (30) in the strip (22) such that the dimples (30) project to the side of the strip (22) opposite the strip one side and the dimples (30) on one side of a predetermined fold line (28) located between opposed edges will align with the dimples (30) on the other side of the fold line (28);
c) placing slits (34) extending through the strip (22) at the apexes (44) of the dimples (30) on at least one side of the fold line (28);
d) folding the strip (22) along the fold line (28) and bringing the edges (24,26) into contact with one another while causing the apexes (44,46) of aligned ones of the dimples (30) to abut one another;
e) welding the edges (24,26) to each other to form a tube; and
f) causing the braze alloy to flow from the strip one side through the slits to the interior of the tube and braze the apexes (44,46) of the aligned dimples (30) together.