Abstract: A heat exchange tube is formed by using a sheet member not clad with a brazing material layer, with bonding regions at which ends of the sheet member are overlapped and brazed by using a brazing material. This structure reduces the extent to which the brazing material becomes dispersed while the heat exchange tube is brazed and the likelihood of dissolution due to erosion, which makes it possible to assure the desired product quality, such as corrosion resistance, even when a tube material with a smaller wall thickness is used.

Abstract: A heat exchange tube is formed by using a sheet member not clad with a brazing material layer, with bonding regions at which ends of the sheet member are overlapped and brazed by using a brazing material. This structure reduces the extent to which the brazing material becomes dispersed while the heat exchange tube is brazed and the likelihood of dissolution due to erosion, which makes it possible to assure the desired product quality, such as corrosion resistance, even when a tube material with a smaller wall thickness is used.

Abstract: In tubular portion of a tank, slits are formed in each side face of chambers or across all side faces of the chambers. For partition plates that are to be inserted from the slits, groove portions in which the partition plates are fitted are formed by cutting portions to which the partition plates butt. The slits are formed in the chambers at positions relatively shifted from each other in a direction in which tubes are layered. This structure guarantees that, in the tank for a heat exchanger, bypass leakage of a heat exchange medium between sub-chambers is prevented from occurring when the partition plates are inserted in the tank from the slits provided on the tank side faces. Further, the tank can maintain required strength even if the slits are formed in it.

Abstract: In a tube (4) for a heat exchanger comprising a flat pipe (16) whose both ends are opened and in which a flow path (15) for a heat exchanging medium is formed, and an inner fin (17) arranged in the flow path (15), wherein said flat pipe (16) is constituted of a sheet of material for a flat pipe, the inner fin is constituted of two opposing flat plate portions (17b, 17c) connected along one of side edges of said flat pipe (16) and formed in a flat plate shape so as to be in contact with an inner surface of the said flat pipe (16), and projection portions (17d) which are projected from at least one of the flat plate portions (17b, 17c) and whose tops are in contact with the other opposing flat plate portion (17b, 17c). It is preferred that the projection portions (17d) are projected from both of the flat plate portions (17b, 17c) toward the opposing flat plate portion, and the opposing tops are made come in contact with each other.

Abstract: A heat exchange tube 4 is formed by using a sheet member not clad with a brazing material layer, with bonding margins 4d at which ends of the sheet member are overlapped and brazed by using a brazing material. This structure reduces the extent to which the brazing material becomes dispersed while the heat exchange tube is brazed and the likelihood of dissolution due to erosion, which makes it possible to assure the desired product quality such as corrosion resistance even when a tube material with a smaller wall thickness is used.

Abstract: Projected portions 34 formed at the external circumferential edge of a tank 2 are made to engage with, at least, groove portions 36 formed at a brazing filler metal supplying member 23 and groove portions 39 formed at a connector 9 to hold the tank 2, the brazing filler metal supplying member 23 and the connector 9 together in a stable state prior to the brazing process. The structure provides a reliable means for supplying brazing filler metal material to be used to braze a tank not clad with a brazing filler metal layer and a connector formed through machining. In addition, it effectively prevents the member constituting the means for brazing filler metal supply from coming off.

Abstract: A die arm 34 and a punch 35 to be used to punch a hole are inserted into chambers 21 and 22 lying parallel to each other along the direction of ventilation through openings located on one side of the chambers along the lengthwise direction. A partition portion 20 has a small wall thickness T1 relative to the wall thicknesses of partition portions in the related art, in a range of equal to or greater than 0.4 mm and equal to or less than 1.65 mm, so as to ensure that the punch unit achieves a high enough level of fatigue resistance to assure a specific number of uses without a failure even though the fulcrum and the power point of the die arm 34 and the punch 35 are not on a single axis along the operating direction and also that the partition portion 20 with the smaller wall thickness still has sufficient strength to prevent deformation.

Abstract: In a tube (4) for a heat exchanger comprising a flat pipe (16) whose both ends are opened and in which a flow path (15) for a heat exchanging medium is formed, and an inner fin (17) arranged in the flow path (15), wherein said flat pipe (16) is constituted of a sheet of material for a flat pipe, the inner fin is constituted of two opposing flat plate portions (17b, 17c) connected along one of side edges of said flat pipe (16) and formed in a flat plate shape so as to be in contact with an inner surface of the said flat pipe (16), and projection portions (17d) which are projected from at least one of the flat plate portions (17b, 17c) and whose tops are in contact with the other opposing flat plate portion (17b, 17c). It is preferred that the projection portions (17d) are projected from both of the flat plate portions (17b, 17c) toward the opposing flat plate portion, and the opposing tops are made come in contact with each other.