Heat exchanger tube and manufacturing method thereof

Abstract

The present invention relates to a heat exchanger tube and a manufacturing method thereof. The heat exchanger tube comprises: a tube forming an inner space; and inner fins configured to be inserted into the inner space of the tube and form a plurality of channels. The tube includes a front edge and a rear edge positioned at opposite sides in the widthwise direction of the inner fins, respectively, and each of the front edge and the rear edge has an outwardly convex round shape.

Description

Heat exchanger tube and method for manufacturing the same

[0001] The present invention relates to a heat exchanger tube and a method for manufacturing a heat exchanger tube.

[0002] Typically, a heat exchanger comprises a pair of header tanks that store a heat exchange medium, and a plurality of tubes connecting the pair of header tanks. The tubes extend between the pair of header tanks and form passages that allow the heat exchange medium to flow between the tanks. The inner space of these tubes is typically divided into a plurality of channels.

[0003] Previously, the primary manufacturing method for these tubes involved folding a single sheet metal multiple times to achieve the desired shape. For example, U.S. Patent No. 7,657,986B2 disclosed a method for forming a U-shaped groove in a single sheet metal and folding it to produce a tube with multiple channels. Since this existing manufacturing method processes a single sheet metal to produce a tube, the outer wall forming the outer portion of the tube and the baffles forming the inner channels had to have the same thickness, which resulted in increased weight and a reduction in the cross-sectional area of ​​the flow path, negatively affecting the performance of the tube and heat exchanger. Furthermore, there was the problem of increased manufacturing costs due to the use of unnecessary materials.

[0004] The matters described in the technical background of this invention are written to enhance understanding of the background of the invention and may include matters that are not already known in the field to which this technology belongs.

[0005] <Prior Art Literature>

[0006] - U.S. Patent Publication No. US7,657,986B2 (February 9, 2010)

[0007] The problem to be solved by the present invention is to provide a method for manufacturing a heat exchanger tube that can achieve weight reduction and increase in the cross-sectional area of ​​the channel flow path by reducing the thickness of the inner structure for forming a channel within the heat exchanger tube.

[0008] In addition, another problem to be solved by the present invention is to provide a method for manufacturing a heat exchanger tube having high structural stability while having a low manufacturing cost and a simple manufacturing process.

[0009] A heat exchanger tube according to an embodiment of the present invention includes a tube forming an inner space, and an inner fin inserted into the inner space of the tube to form a plurality of channels. The tube includes a front edge and a rear edge positioned on each of the widthwise sides of the inner fin, and the front edge and the rear edge each have an outwardly convex round shape.

[0010] The tube may be formed by forming a single flat strip, the front edge of which may include first and second round portions forming a two-layer structure by bending one end of the flat strip, and a connecting portion connecting the first and second round portions.

[0011] The tube may include an upper tube wall and a lower tube wall formed by folding the flat strip to wrap around one end of the inner fin, and the tube may include a support portion configured to support the connecting portion while extending from one end of the upper wall and being in close contact with the connecting portion.

[0012] The inner fin may include a fixed flange that is in close contact with the lower tube wall, and the support member may have a lower end configured to press the fixed flange.

[0013] According to another embodiment of the present invention, one end of the inner fin may include a fixed flange that is in close contact with the lower tube wall, and the tube may further include a pressing portion configured to extend from the lower end of the lower end of the support portion and press the fixed flange.

[0014] The other end of the inner pin may be in close contact with the rear edge, and the rear edge may include a round support portion for supporting the rear edge.

[0015] The inner fin may have a thickness thinner than the tube.

[0016] According to an embodiment of the present invention, a manufacturing method for manufacturing a heat exchanger tube having front edges and rear edges respectively arranged on the front and rear sides and having a plurality of channels therein comprises the steps of: forming a first rounded portion by rotating inwardly a first outer edge of a flat strip having a first outer edge and a second outer edge facing each other along a width direction about a first bent portion spaced inwardly from the first outer edge by a preset distance; forming a first formed portion extending between the first bent portion and the second bent portion by rotating an outer portion of the second bent portion about a second bent portion spaced inwardly from the first bent portion by a preset distance; forming a second formed portion extending between the first bent portion and the third bent portion by rotating an upper portion of the first formed portion about a third bent portion located between the first bent portion and the second bent portion; forming a third formed portion extending between the third bent portion and the second bent portion; A step of forming the front edge by rotating the forming part and the first round part to form the third forming part into a second round part that contacts the first round part and forming the second forming part into a connecting part that connects the first round and the second round part, and a step of forming the fourth forming part that extends between the second outer edge and the fourth bend part by rotating the fourth bend part around a fourth bend part spaced inward by a preset distance from the second outer edge.And, in a state where the inner fin for forming the plurality of channels is placed on the flat strip so as to be adjacent to the connecting portion, a part corresponding to the outer side of the fifth bending portion including the fourth forming portion is rotated around the fifth bending portion located near one end of the inner fin, and a part adjacent to the fifth bending portion is formed as the rear edge, and an upper tube wall and a lower tube wall that contact the upper and lower sides of the inner fin, respectively, are formed, and the fourth forming portion is formed into a support portion by being in close contact with the connecting portion.

[0017] The inner pin may have a fixed flange provided on one end, and the fourth molding part may press the fixed flange during the process of being molded into the support part to bring it into close contact with the upper surface of the flat strip.

[0018] The inner fin may have a round support provided on the other end, and the rear edge may be formed to have a round shape that contacts the round support.

[0019] According to another embodiment of the present invention, a manufacturing method for manufacturing a heat exchanger tube having front edges and rear edges respectively disposed on the front and rear sides and having a plurality of channels therein comprises the steps of: forming a first rounded portion by rotating inwardly a first outer edge of a flat strip having a first outer edge and a second outer edge facing each other along a width direction about a first bent portion spaced inwardly from the first outer edge by a preset distance; forming a first formed portion extending between the first bent portion and the second bent portion by rotating an outer portion of the second bent portion about a second bent portion spaced inwardly from the first bent portion by a preset distance; forming a second formed portion extending between the first bent portion and the third bent portion by rotating an upper portion of the first formed portion about a third bent portion located between the first bent portion and the second bent portion; forming a third formed portion extending between the third bent portion and the second bent portion; A step of forming the front edge by rotating the forming part and the first round part to form the third forming part into a second round part that contacts the first round part and forming the second forming part into a connecting part that connects the first round and the second round part, a step of forming a fourth forming part extending between the second outer edge and the fourth bend part by rotating the fourth forming part around a fourth bend part spaced inwardly from the second outer edge by a preset distance, a step of forming a fifth forming part extending between the fourth bend part and the fifth bend part by rotating the fourth forming part around a fifth bend part spaced inwardly from the fourth bend part by a preset distance,And, in a state where the inner fin for forming the plurality of channels is placed on the flat strip adjacent to the connecting portion, the outer portion of the sixth bending portion including the fourth and fifth forming portions is rotated around the sixth bending portion located near one end of the inner fin, and the portion adjacent to the sixth bending portion is formed as the rear edge, and an upper tube wall and a lower tube wall that contact the upper and lower sides of the inner fin, respectively, are formed, and the fourth forming portion is formed into a support portion by being in close contact with the connecting portion.

[0020] The inner pin may have a fixed flange provided on one end, and the fifth molding part may be formed as a pressing part that presses the fixed flange to adhere it to the upper surface of the flat strip during the process in which the fourth molding part is formed into the support part.

[0021] The inner fin may have a round support provided on the other end, and the rear edge may be formed to have a round shape that contacts the round support.

[0022] According to the present invention, by forming a tube using a flat strip and separately forming a plurality of channels using an inner fin having a thickness thinner than the flat strip, the weight of the heat exchanger tube can be reduced and the cross-sectional area of ​​the channel flow path can be increased. In addition, by forming a double-structured round portion on the front side through which air is introduced and adopting a structure in which a connecting portion connecting the double-structured round portion is supported by a support portion, a heat exchanger tube having a sturdy fastening structure while being easy to manufacture can be realized. In addition, by pressurizing and fixing the fixing flange of the inner fin by the support portion, it is possible to increase the ease of assembly and realize a more sturdy structure by increasing the brazing area.

[0023] FIG. 1 is a schematic perspective view of a heat exchanger to which a heat exchanger tube according to an embodiment of the present invention is applied.

[0024] Figure 2 is a perspective view of a heat exchanger tube according to an embodiment of the present invention.

[0025] Figure 3 is a cross-sectional view taken along line Ⅲ-Ⅲ of Figure 2.

[0026] FIGS. 4A to 4I are drawings showing sequential steps of a method for manufacturing a heat exchanger tube according to an embodiment of the present invention.

[0027] Figure 5 is a cross-sectional view of a heat exchanger tube according to another embodiment of the present invention.

[0028] FIG. 6 is a drawing for explaining a molding process for forming a pressurized portion among the methods for manufacturing the heat exchanger tube of FIG. 5.

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the described embodiments.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "comprises" and / or "comprising," as used herein, indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The term "coupled" indicates a physical relationship between two components in which the components are directly connected to one another or are indirectly connected through one or more intervening components.

[0031] When describing components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected, coupled, or connected to the other component, but that another component may also be "connected," "coupled," or "connected" between each component.

[0032] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0033] Fig. 1 is a schematic perspective view of a heat exchanger to which a heat exchanger tube according to an embodiment of the present invention is applied. Fig. 2 is a perspective view of a heat exchanger tube according to an embodiment of the present invention, and Fig. 3 is a cross-sectional view taken along line Ⅲ-Ⅲ of Fig. 2.

[0034] Figures 2 and 3 illustrate a heat exchanger tube (10) according to an embodiment of the present invention, and the heat exchanger tube (10) illustrated in Figures 2 and 3 can be applied to the heat exchanger (1) exemplarily illustrated in Figure 1. Referring to Figure 1, the heat exchanger (1) includes a pair of header tanks (2, 3) arranged to face each other, and a plurality of heat exchanger tubes (10) fluidly connecting the header tanks (2, 3).

[0035] The header tanks (2, 3) are formed so that heat exchange media such as refrigerant, cooling water, etc. can be introduced and discharged. The heat exchange media moves between the header tanks (2, 3) through the heat exchanger tubes (10), and while the heat exchange media passes through the heat exchanger tubes (10), heat exchange can occur with the air passing around the heat exchanger tubes (10). At this time, heat from the air can be absorbed to cause evaporation of the cooling water or refrigerant, and in this respect, such a heat exchanger can be called an evaporator. Fins (4) for promoting heat exchange can be arranged between the heat exchanger tubes (10). It should be noted that in FIG. 1, for convenience of illustration, most of the fins (4) are omitted, and a case in which the fins (4) are arranged only in a part of the space between the heat exchanger tubes (10) is illustrated as an example.

[0036] Referring to FIGS. 2 and 3, the heat exchanger tube (10) includes a tube (11) and an inner fin (13). The inner fin (13) can be formed separately and then combined with the tube (11) through an assembly process.

[0037] The tube (11) has a roughly flat shape and forms an inner space. The tube (11) includes upper and lower tube walls (15, 16) that face each other at a predetermined distance apart from each other, and front and rear edges (17, 18). The front and rear edges (17, 18) are respectively located on both sides in the width direction of the heat exchanger tube (10). Here, the front may be understood as the side where air flows in and the rear may be understood as the side where air flows out, based on the tube (11) installed in the heat exchanger (100). The front edge (17) and the rear edge (18) are respectively located on both sides in the width direction of the inner fin (13). The front edge (17) may be understood as the right edge of the tube (11) in FIG. 1, and the rear edge (18) may be understood as the left edge of the tube (11) in FIG. 1.

[0038] Referring to FIGS. 2 and 3, the upper and lower tube walls (15, 16) of the tube (11) each have a flat shape, and the front and rear edges (17, 18) have a round shape that protrudes outward. Both longitudinal ends of the tube (11) inserted into the header tank (2, 3) are open, and movement of the heat exchange medium occurs through the open portion of the tube (11).

[0039] The tube (11) can be formed by forming a flat strip, and the front edge (17) includes two rounded portions formed by bending one end of the flat strip, i.e., first and third rounded portions (171, 172). Since the front edge (17) corresponds to the side into which air is introduced, it is formed with a multi-layer structure so as to prevent damage caused by collision with foreign substances mixed in the air. The front edge (17) includes first and second rounded portions (171, 172) formed in two layers, and a connecting portion (173) connecting the first and second rounded portions (171, 172). This front edge (17) can be formed by extending from the end of any one of the tube walls (15, 16), i.e., the lower tube wall (16). In addition, a support portion (151) extending from the end of the upper tube wall (15) is provided, and the support portion (151) is in close contact with the connecting portion (173) to support the front edge (17). The support portion (151) may be formed in a flange shape at the end of the upper tube wall (151). The rear edge (118) corresponds to a portion connecting the upper and lower tube walls (15, 16) and may be formed to be convex outwardly toward the rear. When the tube (11) is used in a condenser, for example, when an external impact by a foreign substance is applied to the round portion (172) of the tube (11) directly exposed to the outside, the durability against the external impact can be improved by the reinforcing structure by the double round portions (171, 172).

[0040] The inner fin (13) is inserted into the tube (11) to form a plurality of channels (21). The channels (21) extend in the longitudinal direction of the tube (11), i.e., in the depth direction in FIG. 3, and act as passages for a heat exchange medium. The inner fin (13) may have a thickness thinner than that of the tube (11) to reduce weight and save material. The tube (11) and the inner fin (13) may each be formed of a plate material, and the inner fin (13) may be formed of a plate material having a thickness that is significantly smaller than the thickness of the plate material for forming the tube (11), for example, a plate material having a thickness of 30% or less of the thickness of the plate material for forming the tube (11). As illustrated in FIGS. 2 and 3, the inner fin (13) may be formed to have a plurality of grooves that are alternately formed up and down. For example, the inner fin (13) may include a first groove bottom portion (131) that contacts the upper tube wall (15), a second groove bottom portion (132) that contacts the lower tube wall (16), and a groove side portion (133) that connects the first groove bottom portion (131) and the second groove bottom portion (132). The groove bottom portions (131, 132) have a function of supporting the upper and lower tube walls (15, 16), and the groove side portion (133) has a function of dividing an adjacent channel (21).

[0041] In addition, as illustrated in part B of FIG. 3, the inner fin (13) may include a round support (134) that is inscribed in the rear edge (18) of the tube (11). The round support (134) may have a round shape corresponding to the inner surface of the rear edge (18). The round support (134) may be formed to contact at least a portion of the inner surface of the rear edge (18). By providing the round support (134), the rear edge (18) can be reinforced, and interference can be minimized when the tube (11) is bent, as will be described later.

[0042] Meanwhile, the inner fin (13) may be provided with a fixing flange (135) at the end of the front edge (17) of the tube (11). Referring to part A of Fig. 3, the fixing flange (135) is pressed against the lower tube wall (16) by the support (151) provided at the end of the upper tube wall (15) described above in the final assembled state. As a result, the inner fin (13) can be fixed at a set position, and when the tube (11) and the inner fin (13) are joined by brazing, a more solid joint can be achieved by increasing the brazing area.

[0043] FIGS. 4A to 4I are drawings showing sequential steps of a method for manufacturing a heat exchanger tube according to an embodiment of the present invention. Hereinafter, a method for manufacturing a heat exchanger tube according to an embodiment of the present invention will be described with reference to FIGS. 4A to 4I.

[0044] Referring to FIG. 4a, a flat strip (41) to be formed into a tube (11) is provided. The flat strip (41) may have a size and shape suitable for forming one or more tubes (11) and may be formed of, for example, a metal suitable for manufacturing tubes (11). The flat strip (41) includes outer edges (42, 43) facing each other along the width direction and extending in the length direction of the tube (11) to be formed.

[0045] Referring to Fig. 4b, forming is performed by rotating the outer edge (42) inward around the first fold (45). At this time, the portion between the outer edge (42) and the first fold (45) is formed into a round shape so as to be convex upward, and the outer edge (42) is in close contact with the upper surface of the flat strip (41). Through this forming, the first round portion (171) of the front edge (17) described above is formed.

[0046] Referring to Fig. 4c, a forming process is performed in which the outer portion is rotated upwards around a second bend (47) spaced inward a predetermined distance from the first bend (45) to be approximately vertically erected. Through this forming process, a substantially vertically erected forming part (50) is formed. The forming part (50) is formed into a second round part (172) and a connecting part (173) through subsequent forming.

[0047]

[0048] *Referring to FIG. 4d, the upper part of the molding part (50) is formed by rotating it inward around the third bend (49) located between the first bend (45) and the second bend (47) so that it is positioned in a substantially horizontal direction. Through this forming, the upper part of the molding part (50) is formed into a horizontal molding part (51) extending approximately horizontally around the third bend (49), and the remaining lower part becomes a vertical molding part (53) that maintains a substantially vertical state. At this time, the end of the first round part (171) is in contact with the side of the vertical molding part (53).

[0049] Referring to Fig. 4e, the horizontal forming part (51) and the first round part (171) are rotated to form the vertical forming part (53) into a round shape that is in contact with the shape of the first round part (172). By this forming, the vertical forming part (53) is formed into the second round part (172), and the horizontal forming part (51) is formed into a connecting part (173) while standing upright.

[0050] Referring to FIG. 4f, a forming process is performed in which the other outer edge (43) of the flat strip (41) is rotated upward by approximately 90 degrees about the fourth bend (55) to form a vertical forming portion (57), and at the same time or separately, a pre-formed inner fin (13) is placed on the flat strip (41). At this time, the inner fin (13) is placed so that the fixed flange (135) is located below the connecting portion (173), and the inner fin (13) is placed on an area occupying approximately half of the width direction of the flat strip (41). The forming process to form the vertical forming portion (57) may be performed before or after the inner fin (13) is placed on the flat strip (41).

[0051] Referring to FIGS. 4g to 4i, a forming process is performed in which a portion (58) where the inner fin (13) is not positioned is rotated in the direction of the arrow around the fifth fold (59) so that the vertical forming portion (57) is inserted between the connecting portion (173) of the front edge (17) and the widthwise end of the inner fin (13). The fifth fold (59) is located near the round support portion (134) of the inner fin (13). During this forming process, the portion adjacent to the fifth fold (59) is formed into a round shape according to the outer shape of the inner fin (13) to form the outer edge (18), and the vertical forming portion (57) is erected vertically and comes into close contact with the side surface of the connecting portion (173) to form the supporting portion (151) described above. In addition, the lower end of the supporting portion (151) presses downward the fixing flange (135) of the inner fin (13). At this time, an upper tube wall (15) and a lower tube wall (16) that contact the upper and lower sides of the inner fin (13) are formed, respectively. By this forming, a heat exchanger tube according to an embodiment of the present invention as illustrated in Fig. 4i can be formed, and each part can be firmly fixed to each other through an additional process such as brazing. At this time, a plurality of heat exchanger tubes can be manufactured by forming them long in the depth direction of Fig. 4i and cutting them.

[0052] Fig. 5 illustrates a heat exchanger tube according to another embodiment of the present invention. The heat exchanger tube according to the embodiment illustrated in Fig. 5 is identical to the embodiment described above, except for the pressurizing member (153) provided at the end of the support member (151). Identical parts are designated by the same reference numerals, and redundant descriptions are omitted.

[0053] Referring to an enlarged portion of C in FIG. 5, the pressurizing portion (153) is bent from the lower end of the support portion (151) and extends approximately horizontally, pressurizing the fixing flange (135) of the inner pin (13) downward. Since the pressurizing portion (153) is assembled in a state of pressing the fixing flange (135), the position of the inner pin (13) can be more firmly fixed, and a firm bond is possible by increasing the area where the subsequent brazing process is performed.

[0054] Fig. 6 is a drawing for explaining a molding process for forming a pressurized portion in the method for manufacturing the heat exchanger tube of Fig. 5, and Fig. 6 corresponds to the process of Fig. 4f described above. The remaining molding processes are the same as those of the previously described embodiment, so redundant descriptions are omitted.

[0055] As shown in Fig. 6, forming is performed by rotating the outer edge (43) of the flat strip (41) about a folded portion (61) spaced apart from the outer edge (43) by a set distance to form a formed portion (62). In addition, forming is performed by rotating the outer portion about a folded portion (63) spaced apart from the folded portion (61) by a set distance to form a formed portion (64). These two forming operations can be performed sequentially, and as shown in Fig. 6, the formed portion (62) formed first can extend approximately horizontally, and the formed portion (64) formed later can extend approximately vertically. By such forming, a formed portion (64) that is approximately vertically erected and a formed portion (62) that extends horizontally from an upper end thereof can be formed.

[0056] The intermediate molded product illustrated in Fig. 6 can be manufactured into a heat exchanger tube illustrated in Fig. 5 by rotating the portion located on the right side of the inner fin (13) as illustrated in Figs. 4g and 4h. At this time, the molded portion (64) extending vertically illustrated in Fig. 6 becomes the support portion (151) of Fig. 5, and the molded portion (62) extending horizontally becomes the pressurizing portion (153) of Fig. 5.

[0057] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and includes all changes and modifications that can be easily modified by a person having ordinary skill in the art to which the present invention pertains and are recognized as equivalent from the embodiments of the present invention.

Claims

1. A tube forming an inner space, and Including an inner fin configured to be inserted into the inner space of the above tube and form a plurality of channels; The above tube includes a front edge and a rear edge respectively positioned on both sides of the width direction of the inner fin, A heat exchanger tube wherein the front edge and the rear edge each have an outwardly convex round shape.

2. In paragraph 1, The above tube is formed by forming a single flat strip, A heat exchanger tube having first and second round portions each having a two-layer structure formed by bending one end of the flat strip, and a connecting portion connecting the first and second round portions.

3. In paragraph 2, The above tube includes an upper tube wall and a lower tube wall formed by folding the above flat strip so as to wrap around one end of the inner fin, A heat exchanger tube including a support member configured to support the connecting portion while the tube extends from one end of the upper wall and is in close contact with the connecting portion.

4. In paragraph 3, The above inner fin includes a fixed flange that is in close contact with the lower tube wall, The above support member is a heat exchanger tube whose lower end is configured to pressurize the above fixed flange.

5. In paragraph 3, One end of the inner fin includes a fixed flange that is in close contact with the lower tube wall, A heat exchanger tube wherein the tube further includes a pressurizing portion configured to extend from a lower end of the lower end of the support member and pressurize the fixed flange.

6. In paragraph 1, A heat exchanger tube having a round support portion, the other end of the inner fin being in close contact with the rear edge and the rear edge supporting the round support portion.

7. In paragraph 1, The above inner fin is a heat exchanger tube having a thickness thinner than the above tube.

8. A manufacturing method for manufacturing a heat exchanger tube having front edges and rear edges respectively arranged on the front and rear sides and having a plurality of channels inside, A step of forming a first round portion having a round shape by rotating the first outer edge of a flat strip having a first outer edge and a second outer edge facing each other along the width direction inwardly about a first folded portion spaced inwardly from the first outer edge by a preset distance, A step of forming a first molded portion extending between the first bend portion and the second bend portion by rotating the outer portion of the second bend portion around the second bend portion spaced apart from the first bend portion by a preset distance; A step of rotating the upper part of the first forming part around the third bend part located between the first bend part and the second bend part to form a second forming part extending between the first bend part and the third bend part and a third forming part extending between the third bend part and the second bend part. A step of forming the third molding part into a second round part that contacts the first round part by rotating the second molding part and the first round part, and forming the second molding part into a connecting part that connects the first round part and the second round part to form the front edge. A step of forming a fourth forming portion extending between the second outer edge and the fourth bend portion by rotating the fourth bend portion centered on the second outer edge spaced inward by a preset distance, and A method for manufacturing a heat exchanger tube, comprising the steps of: arranging the inner fins for forming the plurality of channels on the flat strip so as to be adjacent to the connecting portion; rotating a portion corresponding to the outer side of the fifth bend portion including the fourth forming portion around a fifth bend portion located near one end of the inner fin, forming a portion adjacent to the fifth bend portion as the rear edge, forming an upper tube wall and a lower tube wall which respectively contact the upper and lower sides of the inner fin; and forming the fourth forming portion into a support portion by closely contacting the connecting portion.

9. In paragraph 8, The above inner pin has a fixed flange provided on one end, A method for manufacturing a heat exchanger tube in which the fourth molding part presses the fixed flange during the process of being molded into the support part to adhere it to the upper surface of the flat strip.

10. In paragraph 8, The above inner fin has a round support provided on the other end, A method for manufacturing a heat exchanger tube, wherein the rear edge is formed to have a round shape that contacts the round support.

11. A manufacturing method for manufacturing a heat exchanger tube having front edges and rear edges respectively arranged on the front and rear sides and having a plurality of channels inside, A step of forming a first round portion having a round shape by rotating the first outer edge of a flat strip having a first outer edge and a second outer edge facing each other along the width direction inwardly about a first folded portion spaced inwardly from the first outer edge by a preset distance, A step of forming a first molded portion extending between the first bend portion and the second bend portion by rotating the outer portion of the second bend portion around the second bend portion spaced apart from the first bend portion by a preset distance; A step of rotating the upper part of the first forming part around the third bend part located between the first bend part and the second bend part to form a second forming part extending between the first bend part and the third bend part and a third forming part extending between the third bend part and the second bend part. A step of forming the third molding part into a second round part that contacts the first round part by rotating the second molding part and the first round part, and forming the second molding part into a connecting part that connects the first round part and the second round part to form the front edge. A step of forming a fourth forming portion extending between the second outer edge and the fourth bend portion by rotating the fourth bend portion centered on the second outer edge spaced inward by a preset distance; A step of rotating the fourth molded part around a fifth bend part spaced inwardly from the fourth bend part by a preset distance to form a fifth molded part extending between the fourth bend part and the fifth bend part, and A method for manufacturing a heat exchanger tube, comprising the steps of: arranging an inner fin for forming the plurality of channels on the flat strip so as to be adjacent to the connecting portion; rotating a portion corresponding to the outer side of the sixth bend portion including the fourth and fifth forming portions around a sixth bend portion located near one end of the inner fin, forming a portion adjacent to the sixth bend portion as the rear edge, forming an upper tube wall and a lower tube wall which respectively contact the upper and lower sides of the inner fin, and forming the fourth forming portion into a support portion by closely contacting the connecting portion.

12. In paragraph 11, The above inner pin has a fixed flange provided on one end, A method for manufacturing a heat exchanger tube, wherein the fifth molding part is formed as a pressurizing part that presses the fixed flange to adhere it to the upper surface of the flat strip during the process in which the fourth molding part is formed into the support part.

13. In paragraph 11, The above inner fin has a round support provided on the other end, A method for manufacturing a heat exchanger tube, wherein the rear edge is formed to have a round shape that contacts the round support.

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