Abstract: A fin according to the present disclosure is a corrugated fin formed of a metal plate by bending into a corrugated shape, and the corrugated fin includes peak portions extending in a first direction, valley portions extending in the first direction, and inclined portions connecting the peak portions and the valley portions adjacent to each other. The peak portions and the valley portions are alternately arranged in a second direction perpendicular to the first direction, and a thickness of the metal plate at each apex of the peak portions and the valley portions is larger than a thickness of the inclined portions of the metal plate.

Abstract: A fin according to the present disclosure is a corrugated fin formed of a metal plate by bending into a corrugated shape, and the corrugated fin includes peak portions extending in a first direction, valley portions extending in the first direction, and inclined portions connecting the peak portions and the valley portions adjacent to each other. The peak portions and the valley portions are alternately arranged in a second direction perpendicular to the first direction, and a thickness of the metal plate at each apex of the peak portions and the valley portions is larger than a thickness of the inclined portions of the metal plate.

Abstract: An offset fin manufacturing method for manufacturing offset fins includes a feeding step of feeding a strip plate, a connection forming step of forming a connection in the strip plate, and an offset fin forming step of bending a planar plate portion located between corresponding two of the connections. In the offset fin forming step, each offset fin is formed such that two of top surface portions, which are located at an upstream end and a downstream end, respectively, of the offset fin in a feed direction of the strip plate, are respectively and directly connected to corresponding two of the connections. One of two of lateral surface portions joined to a corresponding one of the two of the top surface portions is not offset, and thereby a length of the corresponding one of the two of the top surface portions measured along a wave continuation direction is increased.

Abstract: In a corrugated plate manufacturing apparatus, each of a plurality of primary forming punches includes a plurality of primary pressable portions that are arranged one after another in a slider reciprocating direction and are pressable by a corresponding one of a plurality of primary sliders. When the primary sliders are sequentially moved toward one side in the slider reciprocating direction, each corresponding one of the primary sliders presses the primary pressable portions of the corresponding one of the primary forming punches to press the primary forming punch against a secondary die.

Abstract: A processing machine for performing a bending operation on a workpiece includes a die, a punch movable in a first direction for pressing the workpiece against the die, a slide member movable in a second direction perpendicular to the first direction, a first cam device that moves the punch toward the die for deforming the workpiece when being actuated by movement of the slide member, a second cam device that moves the punch for pressing a surface of the workpiece when being actuated by movement of the slide member. The pressure angle of the second cam device is smaller than a pressure angle of the first cam device. The processing machine further includes a drive member configured to move the slide member such that the second cam device is actuated after the first cam device is actuated.

Abstract: An offset fin manufacturing method for manufacturing offset fins includes a feeding step of feeding a strip plate, a connection forming step of forming a connection in the strip plate, and an offset fin forming step of bending a planar plate portion located between corresponding two of the connections. In the offset fin forming step, each offset fin is formed such that two of top surface portions, which are located at an upstream end and a downstream end, respectively, of the offset fin in a feed direction of the strip plate, are respectively and directly connected to corresponding two of the connections. One of two of lateral surface portions joined to a corresponding one of the two of the top surface portions is not offset, and thereby a length of the corresponding one of the two of the top surface portions measured along a wave continuation direction is increased.

Abstract: Flat-plate connecting portions are formed in a band plate by a connecting-portion forming unit. The flat-plate connecting portions are cut off by another connecting-portion forming unit except one flat-plate connecting portion so as to form a corrugated-plate connecting portion. A corrugated-plate portion is formed by a corrugation forming unit, so that the corrugated-plate portion has multiple projections arranged in a width direction of the band plate and each of the projections extends in a plate feeding direction. The corrugated-plate connecting portion corresponding to a predetermined connecting number is cut off so as to form a corrugated fin having a predetermined number of corrugated-plate portions.

Abstract: In a corrugated plate manufacturing apparatus, each of a plurality of primary forming punches includes a plurality of primary pressable portions that are arranged one after another in a slider reciprocating direction and are pressable by a corresponding one of a plurality of primary sliders. When the primary sliders are sequentially moved toward one side in the slider reciprocating direction, each corresponding one of the primary sliders presses the primary pressable portions of the corresponding one of the primary forming punches to press the primary forming punch against a secondary die.

Abstract: A processing machine for performing a bending operation on a workpiece includes a die, a punch movable in a first direction for pressing the workpiece against the die, a slide member movable in a second direction perpendicular to the first direction, a first cam device that moves the punch toward the die for deforming the workpiece when being actuated by movement of the slide member, a second cam device that moves the punch for pressing a surface of the workpiece when being actuated by movement of the slide member. The pressure angle of the second cam device is smaller than a pressure angle of the first cam device. The processing machine further includes a drive member configured to move the slide member such that the second cam device is actuated after the first cam device is actuated.

Abstract: A heat exchanger has a flat tube (10) having a curved portion (13). A part of the curved portion (13) is formed by overlapping an outer rim (22) on an inner rim (21). The inner rim (21) has a small curvature region (102). The small curvature region (102) is inclined to a flat plate portion (11), and is defined by a radius larger than a difference between a half of a thickness of the flat tube (10) and a thickness of the outer rim (22). The small curvature region (102) is not beyond a center line (C1) in a thickness of the flat tube (10). The outer rim (22) extends beyond the center line (C1). The outer rim (22) has an end face (22a) placed on the small curvature region (102). The flat tube (10) has flared portions (15, 16) expanded at insertion holes (54).

Abstract: Multiple movable die portions (press punches) are respectively opposing to multiple fixed die portions (block members). Each of the press punches is sequentially pushed down with a predetermined time difference to the corresponding block member to continuously carry out press work to a material inserted into a press-work area between the press punches and the block members. A clearance is formed between a forward end of the press punch and a forward end of the block member at a position shortly before a press-work operating position in order to control a pulling force of the material, so that a shape distortion can be avoided.

Abstract: A method of producing a flat tube T by bending a band-like material M to be worked, wherein the material M to be worked is pre-bent to form a pre-formed groove Md in the material M along the longitudinal center axis thereof. Thereafter, the material M to be worked is gradually moved so that both edge portions of the material M to be worked in the lengthwise direction thereof gradually approach each other with the pre-formed groove Md as a center to form a tubular shape.

Abstract: A cylindrical member of a tube for a heat exchanger is made of a pair of flat plate portions, and a pair of curved portions for connecting the pair of flat plate portions to each other. One of the pair of curved portions constructs a bonded portion in which an outer wall portion and an inner wall portion are bonded to each by brazing in a state where the outer wall portion and the inner wall portion overlap each other. The inner wall portion has a portion opposite to the outer wall portion put into close contact with the outer wall portion and is bonded to the one flat plate portion in a state where a tip end portion of the inner wall portion opposite to the one flat plate portion is separated from the one flat plate portion.

Abstract: Multiple movable die portions (press punches) are respectively opposing to multiple fixed die portions (block members). Each of the press punches is sequentially pushed down with a predetermined time difference to the corresponding block member to continuously carry out press work to a material inserted into a press-work area between the press punches and the block members. A clearance is formed between a forward end of the press punch and a forward end of the block member at a position shortly before a press-work operating position in order to control a pulling force of the material, so that a shape distortion can be avoided.

Abstract: A method of producing a flat tube T by bending a band-like material M to be worked, wherein the material M to be worked is pre-bent to form a pre-formed groove Md in the material M along the longitudinal center axis thereof. Thereafter, the material M to be worked is gradually moved so that both edge portions of the material M to be worked in the lengthwise direction thereof gradually approach each other with the pre-formed groove Md as a center to form a tubular shape.

Abstract: A roll forming apparatus for forming projections on a band plate at predetermined internals with respect to a longitudinal direction of the band plate has a carrying roll between an upstream forming roll unit and a downstream forming roll unit. Projections having a first shape are formed on the band plate by an upstream projection forming roll and an upstream recession forming roll of the upstream forming roll unit. The projections having the first shape are formed into projections having a second shape that is steeper than the first shape by a downstream projection forming roll and a downstream recession forming roll of the downstream forming roll unit. Also, the band plate is carried in a sprocket manner that the projections formed in the upstream forming roll unit sequentially engage with projections of the upstream projection forming roll, recessions of the carrying roll, and projections of the downstream projection forming roll.

Abstract: A tube for a heat exchanger has a tube member and a fin inserted in the tube member. The tube member has a first wall having a first end portion and a second wall having a second end portion. The second end portion of the second wall is folded over the first end portion of the first wall. Also, an end of the fin is held between the first end portion and the second end portion of the tube member. Further, the end of the fin has a bent portion at an end of the first end portion within the folded second end portion. The bent portion of the fin is engaged with the first end portion of the tube member for positioning the fin with respect to the tube member.

Abstract: An offset-shaped fin 4 can be continuously processed by roll molding by a method involving a first step of bending a flat sheet-like material 40A into a concavo-convex shape by a pair of first rollers 5, 5? to form a corrugate sheet 40B; a second step of cutting slopes of the concavo-convex ridges of the corrugate sheet by a pair of second rollers; and a third step of bending the offset portion, offset and cut in the second step, by a pair of third rollers. A pitch-changing method of offset-shaped fins involves a step of supplying offset-shaped fins between at least one pair of pitch-changing rollers rotating while meshing with the other so that at least one pair of pitch-changing rollers clamp the offset-shaped fins between them, allow them to pass through said pitch-changing rollers and change their pitch.

Abstract: A die roll 3 comprises a core part 3a which is formed of an elastic material and faces a punch part 2a of a punch roll 2. The core part 3a presses a bottom portion 4b of a drawn portion 4a of a metal material 4 and is separate from a surrounding die part 3b and is provided with a space 3c at the whole outer periphery of the core part 3a. In accordance with the above configuration, swelling is suppressed at the bottom portion 4b of the drawn portion 4a and production of large wrinkles, which is a reason for folds, can be prevented by increase of pressing areas for preventing wrinkles at both sides of the drawn portion.

Abstract: A die roll 3 comprises a core part 3a which is formed of an elastic material and faces a punch part 2a of a punch roll 2. The core part 3a presses a bottom portion 4b of a drawn portion 4a of a metal material 4 and is separate from a surrounding die part 3b and is provided with a space 3c at the whole outer periphery of the core part 3a. In accordance with the above configuration, swelling is suppressed at the bottom portion 4b of the drawn portion 4a and production of large wrinkles, which is a reason for folds, can be prevented by increase of pressing areas for preventing wrinkles at both sides of the drawn portion.