Abstract: In a heat exchanger in which a number of V-shaped convex portions are arranged in parallel at a surface of a fin, one of a pair of inclined convex portions forming a V-shape is arranged to be inclined to a plus side by an angle a relative to a circulation direction of a gas at a first plane of a fin, the other is arranged to be inclined to a minus side by an angle b, and both of them are arranged by asymmetric angles in a left and right direction, and at a second plane opposed to the first plane, the angles which are asymmetric in the left and right direction are made to be reverse to those of the first plane relative to the circulation direction of the gas.

Abstract: In a heat exchanger in which a number of V-shaped convex portions are arranged in parallel at a surface of a fin, one of a pair of inclined convex portions forming a V-shape is arranged to be inclined to a plus side by an angle a relative to a circulation direction of a gas at a first plane of a fin, the other is arranged to be inclined to a minus side by an angle b, and both of them are arranged by asymmetric angles in a left and right direction, and at a second plane opposed to the first plane, the angles which are asymmetric in the left and right direction are made to be reverse to those of the first plane relative to the circulation direction of the gas.

Abstract: To provide an EGR cooler which has a small number of parts and achieves compact design with low cost. A plurality of flat tubes, each having a bottom to close an end thereof, is arranged in parallel. An opening of each of the flat tubes penetrates through a tube plate. Corrugated fins are placed in each of the flat tubes, thus forming a core. A casing encloses the outer circumferential surface of the core. The tube plate closes the opening of a tank body equipped with a partition. The edge of the partition is placed at an intermediate position in the width direction of the opening of the flat tube.

Abstract: To provide an EGR cooler which has a small number of parts and achieves compact design with low cost. A plurality of flat tubes, each having a bottom to close an end thereof, is arranged in parallel. An opening of each of the flat tubes penetrates through a tube plate. Corrugated fins are placed in each of the flat tubes, thus forming a core. A casing encloses the outer circumferential surface of the core. The tube plate closes the opening of a tank body equipped with a partition. The edge of the partition is placed at an intermediate position in the width direction of the opening of the flat tube.