Abstract: A corrugated fin cutting method includes continuously conveying a fin material formed into a corrugated shape having a plurality of ridge sections and a plurality of valley sections while regulating a number of the ridge sections and positioning the valley sections; and cutting the fin material at a bottom portion of one of the valley sections between a stationary blade member and a rotating blade member as the rotating blade member rotates in one direction with respect to the stationary blade member while the fin material is being conveyed.

Abstract: An oil cooler is contained in a radiator tank. It includes a connecting pipe having an enlarged diameter portion, a heat exchange part including elements and a communicating passage fluidically communicating the elements, and a pipe connector. The pipe connector has a first retaining portion seated on one side of a wall portion of the radiator tank to contain and fix at least a part of the enlarged diameter portion of the connecting pipe by caulking, and a second retaining portion inserted through a through-hole of the wall portion and an one end portion of the communicating passage to fix the heat exchanger part and the wall portion at the other side of the wall portion by caulking.

Abstract: An inner fin (1) of a heat exchanger has, on front and rear faces thereof, protruding ridges (2, 3) protruding in opposite directions to each other. Grooves (4, 5) to serve as passages of a heat exchange medium are formed between the adjacent protruding ridges (2, 3). In wall portions (6) forming these protruding ridges (2, 3), cutout windows (10, 11) are formed to allow the adjacent passages to communicate with each other. Further, protruding weir portions (12, 13) are provided at bottoms of entrances of the cutout windows (10 and 11), so that the heat exchange medium hits against the weir portions to promote diffluence and stirring of the heat exchange medium, thereby enhancing heat exchange efficiency.

Abstract: An inner fin (1) of a heat exchanger has, on front and rear faces thereof, protruding ridges (2, 3) protruding in opposite directions to each other. Grooves (4, 5) to serve as passages of a heat exchange medium are formed between the adjacent protruding ridges (2, 3). In wall portions (6) forming these protruding ridges (2, 3), cutout windows (10, 11) are formed to allow the adjacent passages to communicate with each other. Further, protruding weir portions (12, 13) are provided at bottoms of entrances of the cutout windows (10 and 11), so that the heat exchange medium hits against the weir portions to promote difference and stirring of the heat exchange medium, thereby enhancing heat exchange efficiency.

Abstract: An oil cooler is contained in a radiator tank. It includes a connecting pipe having an enlarged diameter portion, a heat exchange part including elements and a communicating passage fluidically communicating the elements, and a pipe connector. The pipe connector has a first retaining portion seated on one side of a wall portion of the radiator tank to contain and fix at least a part of the enlarged diameter portion of the connecting pipe by caulking, and a second retaining portion inserted through a through-hole of the wall portion and an one end portion of the communicating passage to fix the heat exchanger part and the wall portion at the other side of the wall portion by caulking.

Abstract: A temporary assembling unit for a heat exchanger core including a pair of parallel feed shafts placed facing each other in a predetermined spacing, includes spiral tube guide grooves for guiding ends of a tube of the heat exchanger; and spiral fin guide parts for guiding ends of a corrugated fin of the heat exchanger, the spiral fin guide parts being disposed between the tube guide grooves; wherein an outer diameter of the fin guide part positioned in a supply section of the corrugated fin is smaller than an outer diameter of the tube guide groove.