Abstract: A fin member for a heat exchanger is produced by repeatedly folding a plate over itself into a corrugated shape to form corrugated fins. The folded sections which are formed by the folding are pressed and deformed into a recessed shape to form engagement recesses. A pipe member through which fluid flows is disposed at the engagement recesses. The pressing and deformation of the engagement recesses cause swollen sections to protrude at both sides of each folded section with respect to the folding-over direction of the folded section and form flat butt surfaces at the tips of the swollen sections. Adjacent butt surfaces are caused to be in surface contact with each other with the pipe member disposed at the engagement recesses.

Abstract: A heat exchanger wherein the pipe member is formed in a single stage to reduce the height of the heat exchanger in the thickness direction to enable the heat exchanger to be mounted below the floor of an automobile and wherein the pipe member is prevented from being broken. The heat exchanger includes: fin members formed as corrugated fins and having engagement recesses formed in curved sections; and a pipe member formed by connecting straight pipe sections by U-shaped bend sections, the straight pipe sections being arranged by means of the fin members.

Abstract: A fin member for a heat exchanger is produced by repeatedly folding a plate over itself into a corrugated shape to form corrugated fins. The folded sections which are formed by the folding are pressed and deformed into a recessed shape to form engagement recesses. A pipe member through which fluid flows is disposed at the engagement recesses. The pressing and deformation of the engagement recesses cause swollen sections to protrude at both sides of each folded section with respect to the folding-over direction of the folded section and form flat butt surfaces at the tips of the swollen sections. Adjacent butt surfaces are caused to be in surface contact with each other with the pipe member disposed at the engagement recesses.