Abstract: A tube for a heat exchanger which has beads (21) formed on a brazing sheet (B) for configuring a tube (2) and tops of the beads brazed with opposed portions within a tube part (20) and a method for manufacturing the tube. The tube part (20) prior to brazing is determined to have a thickness (t′) larger than a predetermined thickness (t) and compressed in a direction of its thickness when it is brazed, and the tube which has tops of the beads crushed against or lodged in opposed portions within the tube part. Also a method for manufacturing the tube which can braze the tops of the beads with the opposed portions within the tube more securely and firmly than before.

Abstract: A tube for a heat exchanger which is formed to have beads for dividing passages for a medium in the tube by roll forming, wherein base portions of the beads are formed to have a thickness (B) greater than a thickness of a plate material for the tube. The roll forming has a first step of sequentially bending the plate to have a depressed shape to form portions-to-be-bead which are to be intermediate forms of the beads, a second step of performing a width drawing of the portions-to-be-bead and a third step of compressing the portions-to-be-bead, after the second step, in a direction of the height of the beads, wherein a width (w′) of the depressions of the portions-to-be-bead (21a) in the first step is larger than a width (w) of depressions of beads (21) after forming, and a height (h′) of portions-to-be-bead (21b) after the second step is determined to be higher than a height (h) of the beads (21) after forming.

Abstract: A heat exchanger comprises a plurality of tubes layered with fins intervened between them, header pipes disposed on the end portions of the tubes, and side plates for holding the tube layer, wherein each of the side plates (8) is connected to a side plate insertion hole (10) formed on the header pipe (3) or (4) by inserting its end portion (82) into the side plate insertion hole and forming a taper on the end portion (82) of the side plate (8) to decrease a thickness toward the leading end (82a). The end portions (82) of the side plates (8) are tapered toward the leading ends to decrease a width, contact portions (81a) are formed on the side plate to contact with the outer surface of the header pipes (3), (4), and the contact portions are brazed with the outer surface of the header pipe. Further, a stopper means is formed on the end portions of the side plates to prevent the end portions of the side plates from coming out of the side plate insertion holes (10).

Abstract: A heat exchanger that a tube member 2' has beads 21 protruded from the face of one plate toward the other plate, tube member 2' is held by block members 31, 31, a forming jig 40 is inserted between medium passages 24, 24 formed by the beads 21 to hold to press the beads 21 at an end 2a of the tube member 2' to mutually adhere the faces of the beads 21 on the outer face of the tube member 2', and recesses formed by the mutually contacted faces of the beads 21, 21 have a cross-sectional area of about 0.2 mm.sup.2 or below. And, a region where the recesses have a cross-sectional area of about 0.2 mm.sup.2 or below is within 10 mm outside header pipes 3, 4.