Heat exchanger and method for manufacturing heat exchanger

Abstract

A heat exchanger (1A) comprises: a fin (3A) having a thick plate section (35) and a thin plate section (36) that is thinner than the thick plate section (35) and is adjacent to the thick plate section (35), at least one plate surface of the fin being uneven as a result of the thick plate section (35) and the thin plate section (36) being adjacent to each other; and a plurality of heat transfer tubes (2) that is arranged in a direction perpendicular to the tube axis with the tube axes being parallel to each other, and sandwiches the fin (3A) therebetween. The fin (3A) has a portion protruding more than the plurality of heat transfer tubes (2) in at least one direction among directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes (2). At least a thick plate section (35) among the thick plate section (35) and the thin plate section (36) is provided at the protruding portion of the fin (3A).

Description

Heat exchanger and method for manufacturing the same

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to heat exchangers and methods for manufacturing heat exchangers.

[0002] In heat exchangers, the fins can become deformed during molding, so heat exchangers with fins that are less likely to deform during molding have been developed.

[0003] For example, Patent Document 1 discloses a heat exchanger having a metal strip formed into a corrugated shape and fins formed by folding back both ends of the metal strip in the band direction.

[0004] Japanese Patent Application Laid-Open No. 2003-83691

[0005] The heat exchanger described in Patent Document 1 increases the rigidity of the fins by folding back both ends of the metal strip in the band direction, thereby preventing deformation of the fins themselves. However, this heat exchanger uses a large amount of metal material due to the folded back portions of the metal strip, which results in higher material costs.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a heat exchanger that is highly rigid and can be manufactured using a small amount of material, and a method for manufacturing a heat exchanger.

[0007] To achieve the above object, a heat exchanger according to the present disclosure includes a fin having a thick plate portion and a thin plate portion adjacent to the thick plate portion, the thick plate portion being thinner than the thick plate portion and having at least one plate surface uneven due to the adjacent thick plate portion and the thin plate portion being adjacent to the thick plate portion, and a plurality of heat transfer tubes arranged in a direction perpendicular to the tube axis with the tube axes parallel to each other and sandwiching the fin between them. The fin has a portion that protrudes beyond the plurality of heat transfer tubes in at least one direction perpendicular to the tube axis and the arrangement direction of the heat transfer tubes. Furthermore, at least the thick plate portion of the thick plate portion and the thin plate portion is provided at the protruding portion of the fin.

[0008] According to the configuration of the present disclosure, the fin has a portion that protrudes beyond the heat transfer tubes in at least one direction perpendicular to the tube axis and the arrangement direction of the heat transfer tubes. Furthermore, the protruding portion of the fin is provided with at least a thick plate portion, out of a thick plate portion and a thin plate portion. Therefore, the rigidity is higher than when the entire fin is made of a thin plate. Furthermore, because the rigidity of the fin is ensured, it can be manufactured using less material than when the entire fin is made of a thick plate.

[0009]

[0010] A heat exchanger and a manufacturing method for a heat exchanger according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. In the drawings, identical or equivalent parts are designated by the same reference numerals. In the illustrated Cartesian coordinate system XYZ, the direction in which the axes of the heat transfer tubes of the heat exchanger extend is the vertical direction, and the direction in which the heat transfer tubes are arranged is the horizontal direction. The vertical direction is the Z-axis, the horizontal direction is the X-axis, and the direction perpendicular to the Z-axis and X-axis is the Y-axis. This coordinate system will be referenced as appropriate below.

[0011] (Embodiment 1) A heat exchanger according to embodiment 1 is a heat exchanger in which the thickness of the fins themselves is changed to provide unevenness on the plate surfaces of the fins. First, the overall configuration of the heat exchanger will be described with reference to Figures 1 to 3.

[0012] FIG. 1 is a perspective view of a heat exchanger 1A according to a first embodiment. FIG. 2 is a front view of the heat exchanger 1A. FIG. 3 is an enlarged perspective view of a portion of a heat transfer tube 2 provided in the heat exchanger 1A and a portion of a fin 3A attached to the portion of the heat transfer tube 2. Note that the fin 3A is omitted from FIG. 1 for ease of understanding. Also, in FIG. 2, the shape of the fin 3A is simplified to a shape that is bent multiple times left and right when viewed from the front. In FIGS. 1 to 3, the shape of the heat transfer tube 2 is simplified to a rectangular parallelepiped outer shape with the internal flow paths omitted.

[0013] As shown in Figures 1 and 2, the heat exchanger 1A includes headers 11 and 12 that are connected to external equipment and through which a refrigerant is supplied and discharged, a plurality of heat transfer tubes 2 that are connected to the headers 11 and 12 and through which the refrigerant flows, and fins 3A attached to the heat transfer tubes 2.

[0014] As shown in Fig. 1, the headers 11 and 12 are formed in a cylindrical shape. Although not shown, the headers 11 and 12 are provided with connecting pipes for connection to external devices that supply and discharge the refrigerant. Furthermore, flow paths for distributing and collecting the refrigerant are formed inside the headers 11 and 12. As shown in Fig. 1, the headers 11 and 12 are arranged spaced apart from each other in the vertical direction with their cylindrical axes oriented in the horizontal direction. A plurality of heat transfer tubes 2 are connected to the headers 11 and 12 to circulate the refrigerant between them.

[0015] Each heat transfer tube 2 is formed in a tubular shape to allow the refrigerant to flow, with its tube axis oriented vertically. The upper and lower ends of the heat transfer tubes 2 are inserted into insertion holes (not shown) in the cylindrical walls of the headers 11 and 12. As a result, when the refrigerant flows through the headers 11 and 12, the refrigerant circulates inside the heat transfer tubes 2.

[0016] Each heat transfer tube 2 is made of a metal with high thermal conductivity, such as pure aluminum or an aluminum alloy, to facilitate the transfer of heat from the refrigerant flowing therethrough. Furthermore, the heat transfer tubes 2 are formed in the shape of flat tubes with a flat pipe cross section. The heat exchanger 1A is intended to exchange heat with air blown in the front-to-rear direction during use. To reduce resistance to the air blown, the short axis of the flat pipe cross section of the heat transfer tube 2 is oriented in the left-to-right direction, and the long axis is oriented in the front-to-rear direction. The heat transfer tubes 2 are arranged in the left-to-right direction at regular intervals. Fins 3A are sandwiched between the heat transfer tubes 2, as shown in FIG. 2 .

[0017] The fins 3A have a corrugated plate shape in front view to increase the contact area with the air and improve heat exchange performance. Specifically, the fins 3A are formed from a metal plate with high thermal conductivity, such as a metal plate made of pure aluminum or an aluminum alloy. As shown in FIG. 3 , the fins 3A are formed by bending the metal plate into a corrugated shape with multiple peaks 31 and valleys 33 adjacent to each other in one direction in cross section. The fins 3A are sandwiched between the heat transfer tubes 2 with the direction in which the peaks 31 or valleys 33 are aligned along the tube axis direction D1 of the heat transfer tubes 2, i.e., the Z direction. The fins 3A are brazed to the heat transfer tubes 2 with their tops 32 and bottoms 34 abutting against the heat transfer tubes 2.

[0018] To increase the surface area and improve heat exchange performance, the fins 3A having such a corrugated shape may have a width W1 in the front-to-rear direction, i.e., in the Y direction, that is larger than the width W2 in the Y direction of the heat transfer tube 2. In this case, for example, the fins 3A may be attached to the heat transfer tube 2 with their +Y end portions protruding in the +Y direction, on the downwind side, beyond the heat transfer tube 2 by 1 / 5 to 1 / 50 of the width W1 in the Y direction of the fins 3A.

[0019] However, when the fins 3A are formed into such a shape with width W1 and positioned in such a protruding position, the +Y end portion of the fins 3A protruding in the +Y direction from the heat transfer tube 2 may be deformed by external forces such as collision or contact during manufacturing or use.

[0020] Furthermore, the fins 3A are being made thinner to reduce material costs. Therefore, as the fins 3A are made thinner, the strength and rigidity of the fins 3A themselves tend to decrease. As a result, if the fins 3A formed into the above-described shape and arranged as described above are made even thinner, the ends of the fins 3A, including the +Y end, become more susceptible to deformation, making it difficult to manufacture the fins 3A into the desired shape. Furthermore, it becomes difficult to use the fins 3A in their desired shape.

[0021] Therefore, in the heat exchanger 1A, in order to increase the strength and rigidity, the thickness of the fins 3A itself is changed to provide unevenness on the plate surfaces of the fins 3A. Next, the detailed configuration of the fins 3A will be described with reference to Figures 4 and 5.

[0022] Fig. 4 is an enlarged top view of some of the fins 3A included in the heat exchanger 1A. Fig. 5 is a cross-sectional view taken along the VV section line shown in Fig. 4. For ease of understanding, Fig. 5 shows a cross-section of only the uppermost portion of the corrugated fin 3A extracted and expanded.

[0023] As shown in FIGS. 4 and 5, fin 3A has a thick plate portion 35 provided at the +Y end portion, and a thin plate portion 36 provided on the -Y side of thick plate portion 35 and adjacent to thick plate portion 35.

[0024] As shown in FIG. 5 , the thickness T1 of the thick plate portion 35 is greater than the thickness T2 of the thin plate portion 36. For example, the difference between the thickness T1 of the thick plate portion 35 and the thickness T2 of the thin plate portion 36 is 10% to 90% of the thickness T1 of the plate portion 35. Furthermore, the thickness T1 of the thick plate portion 35 and the thickness T2 of the thin plate portion 36 are both constant. The center line CL1 of the thick plate portion 35 in a cross-sectional view is located on an extension of the center line CL2 of the thin plate portion 36 in a cross-sectional view. Furthermore, the thick plate portion 35 is adjacent to the thin plate portion 36. As a result, the thick plate portion 35 has a step between itself and the thin plate portion 36 on one side of the fin 3A and the other side of the fin 3A. As a result, the thick plate portion 35 forms a protrusion 37 on one side of the fin 3A, i.e., the +Z surface, that protrudes from the thin plate portion 36 in the +Z direction. Furthermore, the thick plate portion 35 forms a protrusion 38 that protrudes in the -Z direction from the thin plate portion 36 on the other surface of the fin 3A, i.e., the -Z surface. As a result, the thick plate portion 35 and the thin plate portion 36 form irregularities on the +Z surface and the -Z surface of the fin 3A. By providing such a configuration, the thick plate portion 35 and the thin plate portion 36 increase the strength and rigidity of the fin 3A.

[0025] The thick plate portion 35 is provided at the +Y end portion of the fin 3A, as shown in FIG. 4 , which protrudes in the +Y direction beyond the heat transfer tube 2. The width of the thick plate portion 35 in the Y direction is, for example, the same as or smaller than the protruding length of the fin 3A in the +Y direction. Alternatively, the width is smaller than the period, i.e., the corrugation pitch, which is the distance between adjacent peaks 32 of the corrugations of the fin 3A. More specifically, the width of the thick plate portion 35 in the Y direction is 1 / 5 to 1 / 50 of the width of the fin 3A in the Y direction. This allows the thick plate portion 35 to increase the strength and rigidity of the +Y end portion of the fin 3A. Because the +Y end portion of the fin 3A protrudes beyond the heat transfer tube 2, it is prone to collision and contact with other objects and is therefore prone to deformation. By providing the thick plate portion 35 at the +Y end portion of the fin 3A, deformation of the +Y end portion is prevented. The cross-sectional area of ​​the thick plate portion 35 is larger than the cross-sectional area of ​​the thin plate portion 36, and as a result, the thick plate portion 35 increases the strength and rigidity of the fin 3A.

[0026] Furthermore, the thick plate portions 35 extend along the peaks 31 and valleys 33 of the corrugated shape of the fin 3A shown in Fig. 3, which are continuous in the Z direction. In other words, the thick plate portions 35 extend in a direction perpendicular to the width direction of the fin 3A. This increases the strength and rigidity of the entire corrugated fin 3A, making it easier for the fin 3A to maintain its corrugated shape.

[0027] 4, the thin plate portion 36 has a plurality of cut-and-raised portions 39 formed therein to allow air to circulate around the fin 3A. The cut-and-raised portions 39 are formed by forming cuts in the metal plate of the fin 3A and bending and raising the portions of the metal plate adjacent to the cuts. Forming the cut-and-raised portions 39 in the thin plate portion 36 rather than in the thick plate portion 35 facilitates the manufacture of the fin 3A.

[0028] The thick plate portion 35 and the thin plate portion 36 are formed by rolling the metal plate from which the fins 3A are made. Because the thin plate portion 36 is formed thinner than the metal plate from which the fins 3A are made, the fins 3A can be manufactured using less material in the manufacture of the heat exchanger 1A compared to manufacturing the fins 3A using the same thickness as the metal plate. Next, a method for manufacturing the heat exchanger 1A will be described with reference to FIGS. 6 and 7.

[0029] Fig. 6 is a flowchart of the method for manufacturing the heat exchanger 1 A. Fig. 7 is a conceptual diagram of a fin forming device 40 used in the method for manufacturing the heat exchanger 1 A.

[0030] First, although not shown, the headers 11, 12 and the heat transfer tubes 2 of the above-described material, shape, and number are prepared. In parallel with the preparation of the heat transfer tubes 2, a rolling process (step S1) shown in FIG. 6 is performed to prepare a plate member, which is the material for the fins 3A. Then, following the rolling process, a fin forming process (step S2) is performed to produce the fins 3A from the prepared plate member. In the rolling process and the fin forming process, for example, a fin forming apparatus 40 shown in FIG. 7 is used.

[0031] The fin forming device 40 includes an uncoiler 42 that supports the core portion of a coil 41 around which a band-shaped metal sheet 4 is wound. Here, the band-shaped metal sheet 4 refers to a band-shaped metal sheet that is the raw material for the fins 3A and is made of a highly heat-conductive metal such as pure aluminum or an aluminum alloy. In the fin forming device 40, the uncoiler 42 rotates the coil 41, thereby pulling out the band-shaped metal sheet 4 from one end of the coil 41. The fin forming device 40 also includes a plurality of dancer rolls 43 around which the pulled-out band-shaped metal sheet 4 is wrapped, and a tension controller 44, which enable the fin forming device 40 to maintain a constant tension in the band-shaped metal sheet 4.

[0032] The fin forming apparatus 40 also includes multiple pairs of rolls 45 arranged vertically to form the rolling process described above. Although not shown, the multiple pairs of rolls 45 have unevenness on their outer peripheries to form the thick and thin portions 35 and 36 described above. A strip metal plate 4, tensioned by multiple dancer rolls 43 and a tension controller 44, passes between the paired rolls 45. As a result, the rolls 45 roll the strip metal plate 4 by rotating themselves to form the plate member 5 having the thick and thin portions 35 and 36 described above. For example, the rolls 45 form the thick portions 35 that are thicker than the strip metal plate 4 and the thin portions 36 that are 10% to 90% thicker than the thick portions 35. In this manner, the fin forming apparatus 40 performs the rolling process (step S1) shown in FIG. 6 .

[0033] During rolling by the rolling rolls 45, minute linear grooves extending in the feed direction D2 of the strip metal plate 4 are formed in the plate member 5 by the rotation of the rolling rolls 45. These minute linear grooves are preferably used to drain water adhering to the fins 3A when the heat exchanger 1A is in use.

[0034] Furthermore, as shown in FIG. 7 , the fin forming apparatus 40 includes multiple sets of forming rolls 46, multiple sets of pitch-reducing rolls 47, and multiple pitch-adjusting rolls 48. Regarding these rolls, the multiple sets of forming rolls 46 have convex portions (not shown) on their outer circumferential surfaces for forming a corrugated shape and concave portions (not shown) adjacent to the convex portions in the circumferential direction, thereby forming semi-finished fins 6 with a larger corrugation pitch than the final fin 3A. Furthermore, the multiple sets of pitch-reducing rolls 47 rotate at a slower speed than the fin forming rolls 46, thereby reducing the corrugation pitch of the semi-finished fin 6. Furthermore, the multiple pitch-adjusting rolls 48 adjust the pitch of the semi-finished fin 6, whose corrugation pitch has been reduced by the pitch-reducing rolls 47, by adjusting their rotational speed or by orienting their roll axes in the direction of travel of the semi-finished fin 6. With this configuration, the fin forming apparatus 40 forms semi-finished fins 6 with the same corrugation shape as the final desired fin 3A.

[0035] The fin forming device 40 also includes a hump unit 49 that slackens the semi-finished fin 6 whose pitch has been adjusted by the pitch adjusting roll 48, and a cutter unit 51 that counts the pitches of the slackened semi-finished fin 6 using a counting worm 50 and cuts the semi-finished fin 6 at a predetermined pitch count. In this way, the fin forming device 40 produces fins 3A with a desired pitch count. In this way, the fin forming device 40 performs the fin forming process (step S2) described above.

[0036] After the rolling process (step S1) and the fin forming process (step S2) are performed using such a fin forming device 40, the core assembly process shown in FIG. 6 is performed using the manufactured fin 3A and the prepared headers 11, 12 and heat transfer tube 2 (step S3).

[0037] In the core assembly process, although not shown, a plurality of prepared heat transfer tubes 2 are arranged with their tube axes parallel to each other and their flat surfaces facing each other. Fins 3A are then sandwiched between the heat transfer tubes 2 with the corrugated waves oriented in the axial direction of the heat transfer tubes 2. This results in a stack of alternately stacked heat transfer tubes 2 and fins 3A. The assembled stack is then compressed in the stacking direction to tightly attach the fins 3A to the heat transfer tubes 2. In this state, one end and the other end of the heat transfer tubes 2 are inserted into insertion holes (not shown) in the prepared headers 11 and 12, and the stack of heat transfer tubes 2 and fins 3A is attached to the headers 11 and 12. This completes the core assembly process. The compressive force applied to the stack is then adjusted, and a restraining jig is attached to the stack to maintain the compressed state of the stack. This completes the core assembly process.

[0038] Following the core assembly process, a brazing process shown in FIG. 6 is performed (step S4). Although not shown in detail, the heat transfer tubes 2 and fins 3A included in the stack with the restraining jig attached are brazed together. The heat transfer tubes 2 are also brazed together with the headers 11 and 12. After brazing, the restraining jig is removed from the stack. This completes the production of the heat exchanger 1A.

[0039] In the manufactured heat exchanger 1A, thick plate portions 35 and thin plate portions 36 are formed in the fins 3A through the rolling process (step S1). As a result, the manufacturing method for the heat exchanger 1A requires less material than manufacturing the fins 3A using the same thickness as the strip metal plate 4 drawn from the coil 41. Furthermore, because the plate member 5 manufactured through the rolling process and the semi-finished fins 6 and fins 3A manufactured through the fin forming process (step S2) each have a thick plate portion 35, the strength and rigidity of the plate member 5, semi-finished fins 6, and fins 3A are high. This reduces the deformation of the plate member 5, semi-finished fins 6, and fins 3A during the manufacturing process of the heat exchanger 1A. As a result, defective fins 3A are less likely to occur. Furthermore, the manufacturing method for the heat exchanger 1A allows for the manufacture of highly accurate fins 3A.

[0040] The above-described strip metal plate 4 is an example of a metal plate as defined in the present disclosure. The above-described plate member 5 is an example of a fin plate member as defined in the present disclosure. The above-described rolling process (step S1) and fin forming process (step S2) are an example of a fin manufacturing method as defined in the present disclosure. The above-described core assembly process (step S3) and brazing (step S4) are an example of an assembly process for attaching the fin 3A to the heat transfer tube 2 as defined in the present disclosure.

[0041] Furthermore, in the steel plate field, a thick plate is generally defined as having a thickness of 6 mm or more, and a thin plate as having a thickness of less than 3 mm. However, in this specification, it is sufficient that the thin plate portion 36 is thinner than the thick plate portion 35, and the thickness regulation of a thick plate in the steel plate field does not apply.

[0042] As described above, in the heat exchanger 1A according to the first embodiment, the fins 3A include the thick plate portions 35 and the thin plate portions 36 that are thinner than the thick plate portions 35 and adjacent to the thick plate portions 35. This provides the fins 3A with greater strength and rigidity than if the entire fins 3A were made of thin plates. Furthermore, to ensure the strength and rigidity of the fins 3A, the fins 3A can be manufactured using less material than if the entire fins 3A were made of thick plates. As a result, the configuration of the heat exchanger 1A reduces material costs.

[0043] In the heat exchanger 1A, the fins 3A protrude beyond the heat transfer tubes 2 in a direction perpendicular to the tube axes of the heat transfer tubes 2 and the arrangement direction of the heat transfer tubes 2. The ends of the fins 3A protruding beyond the heat transfer tubes 2 are prone to colliding with or coming into contact with external objects, but the ends are provided with thick plate portions 35. This gives the fins 3A high strength and rigidity, making them less likely to deform.

[0044] Furthermore, the fin 3A has a corrugated plate shape, and the thick plate portion 35 extends in the direction in which the corrugated peaks 31 and valleys 33 join together, resulting in high strength and rigidity of the entire fin 3A.

[0045] (Variation of Fin Forming Apparatus) In the manufacturing method of the heat exchanger 1A, a fin forming apparatus 40 is used in the rolling step (step S1) and the fin forming step (step S2). The fin forming apparatus 40 includes multiple sets of rolling rolls 45. However, the fin forming apparatus 40 is merely one example of an apparatus that performs the rolling step and the fin forming step. The fin forming apparatus 40 itself does not have to perform the rolling step. As a result, the fin forming apparatus 40 does not have to include the rolling rolls 45.

[0046] Fig. 8 is a conceptual diagram of a modified example of the fin forming device 40 used in the manufacturing method of the heat exchanger 1 A. Fig. 9 is a conceptual diagram of a rolling device 60 used in the manufacturing method of the heat exchanger 1 A.

[0047] As shown in Fig. 8, the fin forming device 40 does not have to be equipped with the reduction rolls 45. In that case, an uncoiler 42 may hold a coil 61 around which a band-shaped plate member 5 having a thick plate portion 35 and a thin plate portion 36 is wound, and the plate member 5 pulled out from the coil 61 may be wound around a dancer roll 43 and then passed between multiple pairs of forming rolls 46 without passing through the reduction rolls 45. The coil 61 may be manufactured by a rolling device 60 shown in Fig. 9. This is because even with this modified example of the fin forming device 40, the fin 3A can be manufactured from a band-shaped plate member 5 having a thick plate portion 35 and a thin plate portion 36.

[0048] The rolling device 60 refers to a device equipped with means for rolling the strip metal plate 4, for example, the rolling rolls 45. To give a specific example, the rolling device 60 is a device equipped with an uncoiler 62 that supports the core portion of the coil 41 around which the strip metal plate 4 is wound, a plurality of dancer rolls 63 that maintain a constant tension on the strip metal plate 4 pulled out from the uncoiler 62, a plurality of sets of rolling rolls 65 that have the same configuration as the plurality of sets of rolling rolls 45 described in the first embodiment, and a recoiler 66 that winds the strip-shaped plate member 5 produced by rolling with the rolling rolls 65 into the coil 61, as shown in FIG.

[0049] In the heat exchanger 1A, the thick plate portions 35 of the fins 3A are rectangular in cross section, and as a result, the corners of the protrusions 37, 38 are right angles in cross section. However, the cross-sectional shape of the protrusions 37, 38 is not limited to this.

[0050] 10A to 10C are cross-sectional views of first to third modified examples of the fins 3A of the heat exchanger 1A.

[0051] As shown in Figures 10A and 10B, in the first and second modified examples of the fin 3A, the front end of the thick plate portion 35, i.e., the +Y end, is rounded. As a result, the corners of the +Y side of the protrusions 37 and 38 in a cross-sectional view are rounded. Furthermore, the -Y end of the thin plate portion 36 is rounded, resulting in the corners of the -Y side of the thin plate portion 36 in a cross-sectional view. This shape is formed by using a roll that presses the widthwise end of the strip metal plate 4 when rolling the strip metal plate 4 with the above-mentioned rolling roll 45, or by providing a guide mechanism on the rolling roll 45 that presses the widthwise end. In this way, the corners of the protrusions 37 and 38 in a cross-sectional view may be rounded in addition to being right-angled. Furthermore, the corners of the protrusions 37 and 38 in a cross-sectional view may be chamfered.

[0052] 10A and 10B, in the first and second modified examples of the fin 3A, multiple steps are formed at the rear end, i.e., the -Y end, of the thick plate portion 35. Specifically, as shown in FIG. 10A, in the first modified example of the fin 3A, two steps are formed between the -Y end of the thick plate portion 35 and the thin plate portion 36. As shown in FIG. 10B, in the second modified example of the fin 3A, three steps are formed between the -Y end of the thick plate portion 35 and the thin plate portion 36. This shape is formed by the above-mentioned rolling roll 45. In this way, the thick plate portion 35 may have multiple steps between it and the thin plate portion 36.

[0053] 10C , in the third modification of the fin 3A, recesses are formed in the thick plate portion 35, so that the thick plate portion 35 does not have a constant thickness but has multiple thicknesses. In this way, the thickness of the thick plate portion 35 may vary in the extension direction, resulting in multiple thicknesses.

[0054] In the heat exchanger 1A, the +Y end portions of the fins 3A protrude beyond the heat transfer tubes 2 in the +Y direction, which is the downwind side shown in Fig. 4, and the thick plate portions 35 are formed only in the protruding portions 30. In other words, the thick plate portions 35 are formed in the portions of the protruding portions 30 that are distant from the heat transfer tubes 2. However, the position of the thick plate portions 35 is not limited to this.

[0055] Fig. 11A is a cross-sectional view of a fourth modified example of the fin 3A included in the heat exchanger 1A, and Fig. 11B is a cross-sectional view taken along the line XIB-XIB shown in Fig. 11A.

[0056] In the heat exchanger 1A shown in Figures 11A and 11B, thick plate portions 35 are formed from the protruding portions 30 of the fins 3A that protrude in the -Y direction beyond the heat transfer tubes 2 to the portions sandwiched between the heat transfer tubes 2. As a result, the base portions of the thick plate portions 35, i.e., the region A1 portion, are sandwiched between the heat transfer tubes 2. Furthermore, the region A1 portion of the thick plate portions 35 is brazed to the heat transfer tubes 2. As a result, the thick plate portions 35 not only increase the strength and rigidity of the protruding portions 30, but also increase the strength and rigidity of the heat exchanger 1A itself. In this way, it is preferable that the thick plate portions 35 are formed not only on the protruding portions 30 of the fins 3A, but also on the fins 3A from the protruding portions 30 to the portions sandwiched between the heat transfer tubes 2.

[0057] 11A and 11B, the +Y end of the fin 3A does not protrude further in the +Y direction than the heat transfer tube 2, and is positioned in the Y direction at the same position as the +Y end of the heat transfer tube 2. A thick plate portion 35 is formed from the +Y end of the fin 3A to the portion sandwiched between the heat transfer tubes 2. In this case, too, the thick plate portion 35 is joined to the heat transfer tube 2, thereby increasing the strength and rigidity of the heat exchanger 1A itself.

[0058] In the fourth modification, unevenness may be provided on the thin plate portion 36. Furthermore, in the fourth modification of the fin 3A, the protruding portion 30 is provided on the −Y side of the fin 3A, but the protruding portion 30 may be provided on the +Y side of the fin 3A.

[0059] (Embodiment 2) In the heat exchanger 1A according to embodiment 1, one thick plate portion 35 is provided at the +Y end of the fin 3A. However, the fin 3A is not limited to this. The fin 3A may include a thick plate portion 35 and a thin plate portion 36 that is thinner than the thick plate portion 35 and adjacent to the thick plate portion 35, and the thick plate portion 35 and the thin plate portion 36 are adjacent to each other, so that at least one plate surface is uneven. Therefore, the fin 3A may be provided with multiple thick plate portions 35. Furthermore, the thick plate portion 35 may be provided at a location other than the +Y end of the fin 3A.

[0060] In the heat exchanger 1B according to the second embodiment, a plurality of thick plate portions 35 and a plurality of thin plate portions 36 are provided over the entire fin 3B. The configuration of the fin 3B will be described below with reference to Figures 12 and 13. The second embodiment will be described mainly with respect to the configuration different from the first embodiment.

[0061] Fig. 12 is an enlarged top view of some fins 3B included in a heat exchanger 1B according to embodiment 2. Fig. 13 is a cross-sectional view taken along the XIII-XIII cutting line shown in Fig. 12. For ease of understanding, the cut-and-raised portions 39 are omitted from Fig. 12. Similarly to Fig. 5, Fig. 13 shows a cross-section of only the uppermost portion of the corrugated fin 3B when it is extracted and unfolded.

[0062] As shown in FIG. 12 , the fin 3B has alternating thick plate portions 35 and thin plate portions 36. As a result, as shown in FIG. 13 , convex portions 37, 38 and concave portions 57, 58 are formed on each plate surface of the fin 3B. Specifically, the fin 3B has alternating thick plate portions 35 and thin plate portions 36 in this order from the +Y end. As a result, convex portions 37 and concave portions 57 are formed alternately on the +Z surface of the fin 3B. Convex portions 38 and concave portions 58 are also formed alternately on the −Z surface of the fin 3B. The distance between adjacent convex portions 37 or adjacent convex portions 38, i.e., the pitch between the convex portions 37 or 38, is, for example, 1 mm or more. This configuration enhances the strength and rigidity of the fin 3B.

[0063] The difference in thickness between the thick plate portion 35 and the thin plate portion 36 should be large enough that when the fin 3B is abutted against the heat transfer tube 2 and brazed, the solder penetrates into the recesses 57, 58 of the thin plate portion 36 or a solder fillet is formed.

[0064] Also in the second embodiment, the +Y end portions of fins 3B protrude in the +Y direction beyond heat transfer tube 2. The +Y end portions of fins 3B are provided with a plurality of thick plate portions 35. As a result, similar to fins 3A described in the first embodiment, the strength and rigidity of the +Y end portions of fins 3B are increased, and deformation of the +Y end portions is prevented.

[0065] Furthermore, although not shown, the thick plate portions 35 and the thin plate portions 36 extend in the direction in which the peak portions 31 and valley portions 33 of the corrugated shape of the fin 3B described in the first embodiment are connected. As a result, the thick plate portions 35 and the thin plate portions 36 are provided over the entire fin 3B. As a result, the thick plate portions 35 and the thin plate portions 36 increase the strength and rigidity of the entire fin 3B and prevent deformation of the corrugation of the entire fin 3B.

[0066] The method for manufacturing the heat exchanger 1B according to the second embodiment is the same as that of the first embodiment, except that the fins 3B are manufactured by using a rolling roll (not shown) having concave and convex portions arranged alternately in the axial direction on its outer periphery, instead of the rolling roll 45 described in the first embodiment. Therefore, a detailed description of the method for manufacturing the heat exchanger 1B will be omitted.

[0067] As described above, in the heat exchanger 1B according to the second embodiment, the thick plate portions 35 and the thin plate portions 36 are provided over the entire fins 3B. Therefore, the strength and rigidity of the entire fins 3B are high, and the fins 3B are less likely to deform.

[0068] Furthermore, since the thick plate portions 35 and thin plate portions 36 are alternately arranged in the fins 3B, the strength and rigidity of the fins 3B are higher than when the entire fins 3B are made thinner. Also, the fins 3B can be manufactured using less material than when the entire fins 3B remain thick, and the material cost of the fins 3B is lower.

[0069] In the second embodiment, cut-and-raised portions 39 (not shown in FIG. 12 ) are provided in the portions of the fin 3B where the thick plate portions 35 and the thin plate portions 36 are alternately arranged. However, the fin 3B is not limited to this. The fin 3B may have an area where the thick plate portions 35 and the thin plate portions 36 are not formed, and the cut-and-raised portions 39 may be provided in that area. This is because such a configuration makes it easier to fabricate the cut-and-raised portions 39, and enables the fabrication of highly accurate cut-and-raised portions 39.

[0070] The heat exchangers 1A, 1B and the manufacturing method for the heat exchangers 1A, 1B according to the embodiment of the present disclosure have been described above, but the heat exchangers 1A, 1B and the manufacturing method for the heat exchangers 1A, 1B are not limited to this.

[0071] For example, in the first embodiment, one thick plate portion 35 is provided at one end portion of the fin 3A. Furthermore, in the first and second embodiments, the fins 3A and 3B each include the thick plate portion 35, so that a convex portion 37 is provided on one surface of the fin 3A and a convex portion 38 is provided on the other surface of the fin 3A and 3B. However, the fins 3A and 3B are not limited to this. The fins 3A and 3B may each include the thick plate portion 35 and a thin plate portion 36 that is thinner than the thick plate portion 35 and adjacent to the thick plate portion 35, and the thick plate portion 35 and the thin plate portion 36 are adjacent to each other, so that at least one plate surface is uneven.

[0072] 14A to 14E are partial cross-sectional views of first to fifth modified examples of the thick plate portion 35 provided on the fin 3A included in the heat exchanger 1A according to embodiment 1. FIGS. 15A to 15F are partial cross-sectional views of sixth to eleventh modified examples of the thick plate portion 35 provided on the fin 3A. FIGS. 16A and 16B are partial cross-sectional views of twelfth and thirteenth modified examples of the thick plate portion 35 provided on the fin 3A.

[0073] 14A and 14B, a thick plate portion 35 may be provided in the center portion of the fin 3A, and thin plate portions 36 may be provided at both end portions. In this case, as shown in Fig. 14A, protrusions 37 and 38 may be provided on each plate surface of the fin 3A, and recesses 57 and 58 may be provided on each plate surface of the fin 3A. Alternatively, as shown in Fig. 14B, protrusions 37 and recesses 57 may be provided on only one plate surface of the fin 3A.

[0074] 14C and 14D, the fin 3A may have thick plate portions 35 at both end portions and a thin plate portion 36 at the center portion. In this case, as shown in Fig. 14C, protrusions 37 and 38 may be provided on each plate surface of the fin 3A, and recesses 57 and 58 may be provided on each plate surface of the fin 3A. As shown in Fig. 14D, the protrusions 37 and recesses 57 may be provided on only one plate surface of the fin 3A.

[0075] Alternatively, as shown in FIG. 14E, thick plate portions 35 and thin plate portions 36 may be alternately provided, and convex portions 37 and concave portions 57 may be provided on only one plate surface of the fin 3A.

[0076] 15A and 15B, the end faces of the thick plate portion 35 may be inclined, so that the convex portions 37 and 38 are trapezoidal in cross section. Also, as shown in FIGS. 15C and 15D, the end faces of the thick plate portion 35 may be inclined and the width of the thick plate portion 35 may be small, so that the convex portions 37 and 38 are triangular in cross section. Furthermore, as shown in FIGS. 15E and 15F, the end faces of the thick plate portion 35 may be arc-shaped, more specifically, semicircular in cross section, so that the convex portions 37 and 38 are semicircular or semielliptical in cross section.

[0077] As shown in FIG. 16A , the fin 3A includes a thick plate portion 59 that is thinner than the thick plate portion 35 and thicker than the thin plate portion 36, in addition to the thick plate portion 35 and the thin plate portion 36. This allows the widths of the protrusions 37 on one plate surface of the fin 3A and the protrusions 38 on the other plate surface of the fin 3A to be different. In this case, the protrusions 37 and 38 may be rectangular. Specifically, the protrusions 37 may be trapezoidal in cross section, and the protrusions 38 may be rectangular in cross section. Alternatively, although not shown, the protrusions 37 may be rectangular in cross section, and the protrusions 38 may be trapezoidal in cross section. Furthermore, as shown in FIG. 16B , even if the thick plate portion 35 has the same thickness, the thick plate portion 35 may have only the protrusions 37 on one plate surface or only the protrusions 38 on the other plate surface, depending on whether the thick plate portion 35 is located on one plate surface side or the other plate surface side of the thin plate portion 36. In this case, too, the protrusion 37 may have a trapezoidal cross section, and the protrusion 38 may have a rectangular cross section. Although not shown, the protrusion 37 may have a rectangular cross section, and the protrusion 38 may have a trapezoidal cross section.

[0078] In the second embodiment, thick plate portions 35 and thin plate portions 36 are alternately formed in the fin 3B. In other words, a combination of thick plate portions 35 and thin plate portions 36 adjacent to the thick plate portions 35 is formed throughout the fin 3B. However, the arrangement of the thick plate portions 35 and thin plate portions 36 is not limited to this. As described above, the thick plate portions 35 and thin plate portions 36 may be adjacent to each other to form irregularities on at least one plate surface.

[0079] Figures 17A-17E are conceptual diagrams of first to fifth modified examples of the arrangement patterns of the thick plate portions 35 and thin plate portions 36 provided on the fin 3B of the heat exchanger 1B according to embodiment 2. For ease of understanding, Figures 17A-17E show the fin 3B when the corrugated structure is unfolded in a straight line. The longitudinal direction of the fin 3B corresponds to the feed direction D2 in which the plate member 5 of the fin forming device 40 shown in Figure 7 is fed into the forming roll 46. For ease of understanding, the irregularities 7-10 formed by the combination of the thick plate portions 35 and thin plate portions 36 described in Figures 13(A)-13(F) and Figures 16A and 16B are shown as solid lines. As a result, the portions of the fin 3B without solid lines are flat surfaces without the irregularities 7-10.

[0080] As shown in Fig. 17A, the fin 3B may be formed with a plurality of irregularities 7 that extend in the longitudinal direction and are arranged in the lateral direction. Furthermore, as shown in Fig. 17B, the fin 3B may be formed with a plurality of irregularities 8 that extend in the lateral direction and are arranged in the longitudinal direction. Furthermore, as shown in Fig. 17C, the fin 3B may have a mixture of a plurality of irregularities 7 that extend in the longitudinal direction and are arranged in the lateral direction, and a plurality of irregularities 8 that extend in the lateral direction and are arranged in the longitudinal direction.

[0081] Here, the longitudinal direction of the fins 3B refers to the longitudinal direction of the fins 3B when they are unfolded into a flat plate, and is the direction in which the heat transfer tubes 2 are arranged in the heat exchanger 1B. The lateral direction of the fins 3B refers to the lateral direction of the fins 3B when they are unfolded into a flat plate, and is the direction perpendicular to the direction in which the heat transfer tubes 2 are arranged in the heat exchanger 1B.

[0082] As shown in Fig. 17D, the fin 3B may have a plurality of projections and recesses 9 formed thereon, each extending in a direction inclined with respect to the longitudinal direction of the fin 3B and parallel to one another. The fin 3B may also have a plurality of projections and recesses 10 formed thereon, each inclined in a different direction with respect to the longitudinal direction. For example, as shown in Fig. 17E, the fin 3B may have a plurality of projections and recesses 9 inclined at a constant angle with respect to the longitudinal direction, and a plurality of projections and recesses 10 inclined line-symmetrically with respect to the plurality of projections and recesses 9.

[0083] In the first and second embodiments, the fins 3A and 3B have a corrugated shape. However, the fins 3A and 3B may have any overall shape as long as they include the thick plate portion 35 and the thin plate portion 36 that is thinner than and adjacent to the thick plate portion 35 and that has an uneven surface on at least one side due to the thick plate portion 35 and the thin plate portion 36 being adjacent to each other. For example, the fins 3A and 3B may have a flat plate shape as a whole.

[0084] Although the heat transfer tubes 2 are flattened in the first and second embodiments, the shape of the heat transfer tubes 2 is arbitrary. For example, the heat transfer tubes 2 may be circular tubes.

[0085] As described above, the heat exchangers 1A and 1B and the manufacturing method thereof are not limited to the above-described embodiment, and various modifications and substitutions can be made. Various embodiments of the present disclosure are described below as appendices.

[0086] (Supplementary Note 1) A heat exchanger comprising: a fin having a thick plate portion and a thin plate portion thinner than the thick plate portion and adjacent to the thick plate portion, at least one plate surface of which is uneven due to the thick plate portion and the thin plate portion being adjacent to each other; and a plurality of heat transfer tubes arranged in a direction perpendicular to the tube axis with their tube axes oriented parallel to each other and sandwiching the fin between them, wherein the fin has portions that protrude beyond the plurality of heat transfer tubes in at least one direction perpendicular to the tube axis and the arrangement direction of the heat transfer tubes, and at least the thick plate portion of the thick plate portion and the thin plate portion are provided on the protruding portions of the fin. (Supplementary Note 2) The heat exchanger according to Supplementary Note 1, wherein the protruding portions of the fin are provided with both the thick plate portion and the thin plate portion. (Supplementary Note 3) The heat exchanger according to Supplementary Note 1, wherein the thick plate portion is provided from the protruding portion of the fin to the portion sandwiched between the fins, and is joined to the fin at the portion sandwiched between the fins. (Supplementary Note 4) The heat exchanger according to any one of Supplementary Notes 1 to 3, wherein the thick plate portion protrudes from the thin plate portion in a quadrangular shape that is rectangular or trapezoidal in cross section. (Supplementary Note 5) The heat exchanger according to any one of Supplementary Notes 1 to 3, wherein the thick plate portion protrudes from the thin plate portion in a triangular shape in cross section. (Supplementary Note 6) The heat exchanger according to any one of Supplementary Notes 1 to 3, wherein the thick plate portion protrudes from the thin plate portion in a semicircular shape in cross section. (Supplementary Note 7) The heat exchanger according to any one of Supplementary Notes 1 to 6, wherein the thick plate portion and the thin plate portion extend in the arrangement direction of the heat transfer tubes. (Supplementary Note 8) The heat exchanger according to any one of Supplementary Notes 1 to 7, wherein the thick plate portions and the thin plate portions extend in a direction perpendicular to the arrangement direction of the heat transfer tubes. (Supplementary Note 9) The heat exchanger according to any one of Supplementary Notes 1 to 7, wherein the thick plate portions and the thin plate portions extend in a direction inclined with respect to the arrangement direction of the heat transfer tubes. (Supplementary Note 10) The heat exchanger according to any one of Supplementary Notes 1 to 9, wherein the fins have a corrugated shape in which peaks and valleys are connected in the direction of the tube axis.(Supplementary Note 11) A method for manufacturing a fin plate member, comprising: a rolling step of sandwiching a metal plate between a pair of rolls, at least one of which has a convex portion and a concave portion adjacent to the convex portion on an outer circumferential surface, and rotating the pair of rolls to roll the metal plate, to produce a fin plate member having a thick portion and a thin portion thinner than the thick portion and adjacent to the thick portion, wherein at least one plate surface is uneven due to the thick portion and the thin portion, and the thick portion is formed at an end portion; a fin forming step of forming a corrugated fin from the fin plate member; and a step of assembling the fin to the heat transfer tubes by arranging a plurality of heat transfer tubes in a direction perpendicular to the tube axes with the tube axes oriented parallel to each other and sandwiching the fin between the plurality of heat transfer tubes, wherein in the step of assembling the fin to the heat transfer tubes, the end portion of the fin where the thick portion is formed protrudes beyond the plurality of heat transfer tubes in at least one direction perpendicular to the tube axes and the arrangement direction of the heat transfer tubes. A method for manufacturing a heat exchanger. (Appendix 12) The method for manufacturing a heat exchanger according to Appendix 11, wherein in the rolling step, the pair of rolls roll the metal plate to form the fin plate member having fine linear grooves, and the fine linear grooves extend in a feed direction in which the metal plate is fed by rotation of the pair of rolls. (Appendix 13) The method for manufacturing a heat exchanger according to Appendix 11 or 12, wherein the metal plate has a band shape, and in the rolling step, the band-shaped fin plate member is manufactured by rolling the metal plate with the band extending in the feed direction in which the pair of rolls feed the metal plate by rotation, and the fin forming step bends the fin plate member in the direction in which the band extends to manufacture the corrugated fins.

[0087] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to explain the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and within the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

[0088] This application is based on Japanese Patent Application No. 2023-51942, filed on March 28, 2023. The entire specification, claims, and drawings of Japanese Patent Application No. 2023-51942 are incorporated herein by reference.

[0089] 1A, 1B Heat exchanger, 2 Heat transfer tube, 3A, 3B Fin, 4 Strip metal plate, 5 Plate member, 6 Semi-finished fin, 7-10 Concave and concave, 11, 12 Header, 30 Protruding portion, 31 Peak portion, 32 Crest, 33 Valley portion, 34 Bottom, 35 Thick plate portion, 36 Thin plate portion, 37, 38 Convex portion, 39 Cut-and-raised portion, 40 Fin forming device, 41 Coil, 42 Uncoiler, 43 Dancer roll, 44 Tension controller, 45 Rolling roll, 46 Forming roll, 47 Pitch reducing roll, 48 Pitch adjusting roll, 49 Hump unit, 50 Counting worm, 51 Cutter unit, 57, 58 Concave portion, 59 Thick plate portion, 60 Rolling device, 61 Coil, 62 Uncoiler, 63 Dancer roll, 65 Rolling roll, 66 recoiler, D1 tube axial direction, D2 feed direction, W1, W2 width, CL1, CL2 center line.

Claims

1. A fin having a thick plate portion and a thin plate portion adjacent to the thick plate portion and thinner than the thick plate portion, wherein at least one plate surface is uneven due to the adjacent thick plate portion and thin plate portion, a plurality of heat transfer tubes arranged in a direction perpendicular to the tube axis with their tube axes parallel to each other and sandwiching the fin therebetween, comprising: the fin has a portion protruding beyond the plurality of heat transfer tubes in at least one direction among the directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes, at least the thick plate portion of the thick plate portion and the thin plate portion is provided in the protruding portion of the fin, the thick plate portion is provided from the protruding portion of the fin to the portion sandwiched between the heat transfer tubes, and is joined to the heat transfer tubes at the portion sandwiched between the heat transfer tubes, a heat exchanger.

2. A fin having a thick plate portion and a thin plate portion adjacent to the thick plate portion and thinner than the thick plate portion, wherein at least one plate surface is uneven due to the adjacent thick plate portion and thin plate portion, a plurality of heat transfer tubes arranged in a direction perpendicular to the tube axis with their tube axes parallel to each other and sandwiching the fin therebetween, comprising: the fin has a portion protruding beyond the plurality of heat transfer tubes in at least one direction among the directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes, at least the thick plate portion of the thick plate portion and the thin plate portion is provided in the protruding portion of the fin, the thick plate portion protrudes in a triangular shape from the thin plate portion in a cross-sectional view, a heat exchanger.

3. A fin having a thick plate portion and a thin plate portion adjacent to the thick plate portion and thinner than the thick plate portion, wherein at least one plate surface is uneven due to the adjacent thick plate portion and thin plate portion, a plurality of heat transfer tubes arranged in a direction perpendicular to the tube axis with their tube axes parallel to each other and sandwiching the fin therebetween, comprising: the fin has a portion protruding beyond the plurality of heat transfer tubes in at least one direction among the directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes, at least the thick plate portion of the thick plate portion and the thin plate portion is provided in the protruding portion of the fin, the thick plate portion protrudes in a semi-circular shape from the thin plate portion in a cross-sectional view, a heat exchanger.

4. A fin having a thick plate portion and a thin plate portion adjacent to the thick plate portion and thinner than the thick plate portion, wherein at least one plate surface is uneven due to the adjacent thick plate portion and thin plate portion, A plurality of heat transfer tubes arranged in a direction perpendicular to the tube axes with the tube axes parallel to each other, and sandwiching the fins between them. Comprising The fins have portions protruding beyond the plurality of heat transfer tubes in at least one direction among the directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes. At least the thick plate portion of the thick plate portion and the thin plate portion is provided on the protruding portion of the fin. The thick plate portion and the thin plate portion extend in the arrangement direction of the heat transfer tubes. Heat exchanger. **Claim 5**: A thick plate portion, a thin plate portion thinner than the thick plate portion, and a fin having a thin plate portion adjacent to the thick plate portion, wherein at least one plate surface is uneven due to the adjacent thick plate portion and thin plate portion. A plurality of heat transfer tubes arranged in a direction perpendicular to the tube axes with the tube axes parallel to each other, and sandwiching the fins between them. Comprising The fins have portions protruding beyond the plurality of heat transfer tubes in at least one direction among the directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes. At least the thick plate portion of the thick plate portion and the thin plate portion is provided on the protruding portion of the fin. The thick plate portion and the thin plate portion extend in a direction inclined with respect to the arrangement direction of the heat transfer tubes. Heat exchanger. **Claim 6** Both the thick plate portion and the thin plate portion are provided on the protruding portion of the fin. The heat exchanger according to any one of claims 1 to 5. **Claim 7** The thick plate portion protrudes in a rectangular or trapezoidal shape from the thin plate portion in a cross-sectional view. The heat exchanger according to any one of claims 1, 4, and 5. **Claim 8** The thick plate portion and the thin plate portion extend in a direction perpendicular to the arrangement direction of the heat transfer tubes. The heat exchanger according to any one of claims 1 to 5. **Claim 9** The fins have a corrugated shape in which mountain portions and valley portions are connected in the direction of the tube axis. The heat exchanger according to any one of claims 1 to 5. **Claim 10**: By sandwiching a metal plate between a pair of rolls, at least one of which has a convex portion and a concave portion adjacent to the convex portion on the outer peripheral surface, and rotating the pair of rolls to roll the metal plate, a thick plate portion, a thin plate portion thinner than the thick plate portion, and a thin plate portion adjacent to the thick plate portion are formed. By having the thick plate portion and the thin plate portion, at least one plate surface is uneven, and a fin plate member having the thick plate portion formed at the end is produced. A rolling process A fin forming step of forming corrugated fins from the fin plate member; A step of assembling the fins to the heat transfer tubes by arranging a plurality of heat transfer tubes in a direction perpendicular to the tube axes with the tube axes facing parallel to each other and sandwiching the fins between the plurality of heat transfer tubes; comprising; In the step of assembling the fins to the heat transfer tubes, at least one direction among the directions perpendicular to the tube axis and the arrangement direction of the heat transfer tubes, the end portion of the fin where the thick plate portion is formed is protruded from the plurality of heat transfer tubes; In the rolling step, the pair of rolls roll the metal plate to form the fin plate member having minute linear grooves; The minute linear grooves extend in the feed direction in which the pair of rolls feed the metal plate by rotation; A method of manufacturing a heat exchanger.

11. The metal plate has a strip shape; In the rolling step, the strip-shaped fin plate member is produced by rolling the metal plate with the direction in which the strip of the metal plate extends in the feed direction in which the pair of rolls feed the metal plate by rotation; In the fin forming step, the corrugated fins are produced by bending the fin plate member in the direction in which the strip extends; The method of manufacturing a heat exchanger according to Claim 10.