Heat exchanger, and method for manufacturing heat exchanger

Abstract

To provide a heat exchanger easy to drain condensate water, and to provide a method for manufacturing a heat exchanger.SOLUTION: A heat exchanger includes: a plurality of flat pipes extending along a vertical direction and disposed in parallel; and corrugate fins disposed between the adjacent flat pipes. The corrugate fins each has: a non-exposed part whose position occupying in a ventilation direction is overlapped on a position occupied by the flat pipes in the ventilation direction; and an exposed part projecting further than the flat pipes in the ventilation direction. On the exposed part, a folded part folded toward the adjacent flat pipes is formed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger and a method for manufacturing a heat exchanger. [Background technology]

[0002] Patent Document 1 discloses a heat exchanger that improves the drainage of corrugated fins. This heat exchanger is formed with drainage slits that serve as through-holes for draining water from the fins. Patent Document 2 discloses a heat exchanger that allows condensed water to flow smoothly down. This heat exchanger includes corrugated fins, a lower header pipe, and a drain guide plate that contacts a drain pan. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6734002

[0004] [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-025462 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a heat exchanger that facilitates drainage of condensed water, and a method for manufacturing the heat exchanger. [Means for solving the problem]

[0006] A heat exchanger according to a first aspect of the present disclosure comprises a plurality of flat tubes extending in an up-down direction and arranged in parallel, and corrugated fins arranged between adjacent flat tubes, wherein the corrugated fins have a non-exposed portion whose position in the ventilation direction overlaps with the position occupied by the flat tubes in the ventilation direction, and an exposed portion that protrudes further than the flat tubes in the ventilation direction, and the exposed portion has a bent portion that is bent toward the adjacent flat tube.

[0007] A heat exchanger according to a second aspect of the present disclosure comprises a plurality of flat tubes arranged in parallel and corrugated fins arranged between adjacent flat tubes, wherein the corrugated fins have non-exposed portions whose positions in the ventilation direction overlap with the positions occupied by the flat tubes in the ventilation direction, and exposed portions that protrude further than the flat tubes in the ventilation direction, and wherein slits are formed in the exposed portions that allow the exposed portions to be bent toward the flat tubes.

[0008] A method for manufacturing a heat exchanger according to a third aspect of the present disclosure includes the steps of fixing a corrugated fin having a slit formed therein between a plurality of flat tubes arranged in parallel, and bending the corrugated fin toward the flat tubes using the slit as a boundary to form a bent portion. [Effects of the Invention]

[0009] The heat exchanger according to the first aspect of the present disclosure can easily allow adhering condensed water to flow along the bent portions, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0010] In the heat exchanger according to the second aspect of the present disclosure, the bent portion for draining condensed water can be formed simply by bending the exposed portion toward the flat tube at the slit as a boundary, which makes it easy to provide a heat exchanger that easily drains condensed water.

[0011] The method for manufacturing a heat exchanger according to the third aspect of the present disclosure can form a heat exchanger having a bent portion through a simple manufacturing process, making it easy to provide a heat exchanger that allows condensed water to be easily drained. [Brief explanation of the drawings]

[0012] [Figure 1] Overall view of a heat exchanger according to embodiment 1 [Figure 2] Enlarged view of a part of the heat exchanger [Figure 3] Front view of the corrugated fin [Figure 4] Side view of the heat exchanger from the right [Figure 5] FIG. 10 is a perspective view of a corrugated fin according to a second embodiment. [Figure 6] Cross-sectional view of a heat exchanger according to a second embodiment [Figure 7] Cross-sectional view taken along the line VII-VII in Figure 6 [Figure 8] 10 is a plan view of a pressed metal plate according to the third embodiment. [Figure 9] 10 is a cross-sectional view of a heat exchanger at the end of an assembly process according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Findings that formed the basis of this disclosure) At the time the inventors conceived the present disclosure, heat exchangers with corrugated fins were known in the heat exchanger technical field. Such heat exchangers had a problem in that, depending on the orientation of the heat exchanger, condensed water adhering to the corrugated fins could easily accumulate without being drained. To address this problem, a technique was proposed in which drainage slits were formed as through-holes in the corrugated fins and the condensed water was drained through the drainage slits. Another technique was proposed in which a drainage guide plate was provided in the heat exchanger in contact with the corrugated fins, the lower header pipe, and the drain pan, and the condensed water was drained through the drainage guide plate. However, the inventors discovered a problem in which, when drainage slits were provided, the surface area of ​​the corrugated fins in the horizontal direction was larger than the diameter of the drainage slits, and therefore, surface tension acted on the condensed water more strongly than gravity, causing the condensed water to easily accumulate on the corrugated fins. Furthermore, the inventors have discovered that providing a drainage guide plate increases the number of parts in the heat exchanger, which tends to lead to increases in material costs, parts management costs, and manufacturing costs, as well as reduced productivity, etc. The inventors have come up with the subject matter of the present disclosure in order to solve these problems. Therefore, the present disclosure provides a heat exchanger that allows condensed water to be easily drained, and a method for manufacturing the heat exchanger.

[0014] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0015] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to the drawings. [1-1.Configuration] [1-1-1. Overall configuration of heat exchanger] Fig. 1 is an overall view of a heat exchanger 1 according to a first embodiment. Fig. 2 is an enlarged view of a portion of the heat exchanger 1. In the drawing, X indicates the right direction, Y indicates the forward direction, and Z indicates the vertically upward direction. The heat exchanger 1 is used, for example, in an outdoor unit of an air conditioner, and exchanges heat between the internal refrigerant and outside air.

[0016] The heat exchanger 1 has a plurality of flat tubes 10 arranged parallel to one another in the vertical direction. The flat tubes 10 are tubes with a flat cross-sectional shape in a horizontal cross section and have a plurality of microchannels inside. The plurality of flat tubes 10 are oriented such that the longitudinal directions and lateral directions of each cross-sectional shape are parallel to one another. Hereinafter, the longitudinal direction of the plurality of flat tubes 10 in a horizontal cross section will be referred to as the first direction, and the lateral direction will be referred to as the second direction. The plurality of flat tubes 10 are arranged with their positions aligned in the first direction. The plurality of flat tubes 10 are also arranged side by side along the second direction. In this embodiment, the first direction is the front-to-rear direction, and the second direction is the left-to-right direction.

[0017] The upper ends of the multiple flat tubes 10 are connected to an upper header pipe 11. The lower ends of the multiple flat tubes 10 are connected to a lower header pipe 13. Each header pipe 11, 13 is a hollow pipe connected to a refrigerant piping of an air conditioner or the like. In this embodiment, the heat exchanger 1 is connected to a refrigeration circuit of the air conditioner or the like so that it can function at least as an evaporator. When the heat exchanger 1 functions as an evaporator, the lower header pipe 13 is upstream of the flat tubes 10 in the flow of refrigerant, and the upper header pipe 11 is downstream of the flat tubes 10.

[0018] FIG. 3 is a diagram showing the corrugated fins 30 as seen from the front. The heat exchanger 1 is provided with the corrugated fins 30. The corrugated fins 30 are made of sheet metal made of a metal with high thermal conductivity, such as aluminum. The corrugated fins 30 are formed by repeatedly bending the sheet metal into a wave shape, and have multiple fins 31 arranged in the vertical direction. The multiple fins 31 are connected to each other via bent portions 33. The corrugated fins 30 are arranged between adjacent flat tubes 10, with each bent portion 33 in contact with the flat tube 10. The corrugated fins 30 are fixed to the flat tubes 10 by brazing or the like.

[0019] The fins 31 of the corrugated fins 30 are arranged with gaps between them above and below. Therefore, the heat exchanger 1 is configured to allow ventilation through the spaces between the fins 31. In this specification, the direction parallel to the direction in which air passes through the heat exchanger 1 is referred to as the ventilation direction. The ventilation direction is parallel to the longitudinal direction of the horizontal cross section of the flat tubes 10, i.e., the first direction. In this embodiment, the ventilation direction is the front-to-rear direction.

[0020] Each fin 31 has a non-exposed portion 35. The non-exposed portion 35 is a portion of the fin 31 whose position in the ventilation direction overlaps with the position of the flat tubes 10 in the ventilation direction. The non-exposed portion 35 is configured in a generally horizontal plate shape. In this embodiment, the metal sheet constituting the corrugated fin 30 is bent in a triangular wave shape, and two adjacent non-exposed portions 35 form a generally V-shape when viewed along the ventilation direction. That is, in this embodiment, the non-exposed portion 35 is configured in a plate shape that is slightly inclined from the horizontal plane. Furthermore, in this embodiment, each fin 31 is formed in a wave-like bent shape in the ventilation direction.

[0021] FIG. 4 is a side view of the heat exchanger 1 as viewed from the right, showing the lower portion 2 and upper portion 3 of the heat exchanger 1. As shown in FIGS. 2 and 4, the corrugated fins 30 are provided with exposed portions 37. The exposed portions 37 are portions of the fins 31 whose positions in the airflow direction do not overlap with the positions of the flat tubes 10 in the airflow direction. In other words, the exposed portions 37 are portions of each fin 31 of the corrugated fins 30 that protrude beyond the flat tubes 10 in the airflow direction. In this embodiment, the exposed portions 37 are provided on both sides of the non-exposed portions 35 in the airflow direction. Also, in this embodiment, the exposed portions 37 are provided on the fins 31 of the corrugated fins 30 that are located in the lower portion 2 of the heat exchanger 1. On the other hand, the fins 31 of the corrugated fins 30 that are located in the upper portion 3 of the heat exchanger 1 do not have the exposed portions 37, but only have the non-exposed portions 35.

[0022] 4, in the ventilation direction, the dimension L1 of each exposed portion 37 is smaller than the dimension L2 of the non-exposed portion 35. In other words, in the ventilation direction, the dimension L1 of each exposed portion 37 is smaller than the dimension L2 of the flat tube 10. In this embodiment, in the ventilation direction, the dimension L1 of each exposed portion 37 is less than half the dimension L2 of the non-exposed portion 35.

[0023] 2 and 3, the exposed portion 37 of each fin 31 is formed with a bending start portion 38 and a bending portion 39. The bending start portion 38 is connected to the non-exposed portion 35 and is a portion that protrudes in the air blowing direction. In this embodiment, the bending start portion 38 is formed at both ends of the exposed portion 37 in the second direction. The bending start portion 38 corresponds to the "starting point of the bending portion" in this embodiment.

[0024] The bent portions 39 are formed by bending a portion of the exposed portion 37 closer to the center than the bent starting point 38, starting from the bent starting point 38, in a direction that forms a crease along the ventilation direction. In other words, the bent portions 39 are portions of the exposed portion 37 that are bent from the bent starting point 38 toward the flat tube 10 adjacent to the bent starting point 38. The bent portions 39 are not directly connected to the non-exposed portion 35, but are indirectly connected to the non-exposed portion 35 via the bent starting point 38. In this embodiment, each bent portion 39 is bent downward from the bent starting point 38. In this embodiment, two bent portions 39 are formed for one exposed portion 37, each bent starting from two bent starting points 38.

[0025] As shown in FIG. 3 , when viewed along the ventilation direction, the bent portions 39 of this embodiment are inclined more toward the vertical direction than the non-exposed portions 35. Furthermore, in this embodiment, the length L3 of each bent portion 39 when viewed along the ventilation direction is greater than the maximum vertical distance D1 between adjacent non-exposed portions 35. Furthermore, in this embodiment, each bent portion 39 is bent to a large angle along the vertical direction. Therefore, each bent portion 39 is close to the bent portion 39 formed in the exposed portion 37 located one level below. Furthermore, as shown in FIG. 4 , the lowest bent portion 39 of the corrugated fin 30 is close to the lower header pipe 13. In this specification, the phrase "a subject is close to an object" means that the subject is in contact with the object, or that the subject is close enough to the object that water flowing along the subject toward the object flows directly onto the object without dripping.

[0026] [1-2. Operation / effect] The operation and function of the heat exchanger 1 configured as above when it functions as an evaporator will be described below.

[0027] When the heat exchanger 1 functions as an evaporator, the refrigerant flows from a refrigerant piping outside the heat exchanger 1 into the lower header pipe 13. The refrigerant that has flowed into the lower header pipe 13 flows into the flat tubes 10 and flows upward inside the flat tubes 10. At this time, air passes through the heat exchanger 1 in one of the ventilation directions, for example, by driving a fan outside the heat exchanger 1. The refrigerant in the flat tubes 10 receives heat from the air passing through the heat exchanger 1 via the corrugated fins 30 and the flat tubes 10. The refrigerant then flows out through the upper header pipe 11 into the refrigerant piping outside the heat exchanger 1.

[0028] That is, when the heat exchanger 1 functions as an evaporator, the air passing through the heat exchanger 1 is cooled. Therefore, when the heat exchanger 1 functions as an evaporator, condensed water adheres to various parts of the heat exchanger 1. The condensed water that adheres to the heat exchanger 1 is drained downward mainly by gravity. However, each fin 31 of the corrugated fin 30 has a generally horizontal, plate-shaped non-exposed portion 35. Therefore, in conventional corrugated fin heat exchangers, condensed water is easily held in the non-exposed portion 35 by surface tension and tends to accumulate on the corrugated fins 30.

[0029] In contrast, the heat exchanger 1 of the present embodiment has exposed portions 37 that protrude further than the flat tubes 10 in the airflow direction, and the exposed portions 37 have bent portions 39 that are bent toward the flat tubes 10. Therefore, condensed water held in the non-exposed portions 35 by surface tension is easily guided toward the bent portions 39 by the surface tension acting between the bent portions 39 and the non-exposed portions 35. Because the bent portions 39 have a greater vertical inclination than the non-exposed portions 35, the condensed water guided to the bent portions 39 is more likely to flow downward due to the action of gravity.

[0030] In this embodiment, the length L3 of the bent portions 39 as viewed along the ventilation direction is greater than the maximum vertical distance D1 between adjacent non-exposed portions 35. Therefore, the bent portions 39 are close to the bent portions 39 formed on the fin 31 one level below, and condensed water can easily flow downward smoothly along the bent portions 39. Furthermore, in this embodiment, the lowest bent portion 39 is close to the lower header pipe 13, and therefore condensed water that flows downward along the bent portions 39 can easily flow directly onto the outer surface of the lower header pipe 13.

[0031] In this embodiment, the exposed portion 37 and the bent portion 39 are provided on each fin 31 of the corrugated fins 30 located in the lower portion 2 of the heat exchanger 1. Because water is retained in the lower portion 2 of the heat exchanger 1 due to the surface tension of the upper surface of the lower header pipe 13, condensed water is more likely to accumulate in the lower portion 2 than in the upper portion 3 of the heat exchanger 1. When the heat exchanger 1 functions as an evaporator, refrigerant flows into the lower portion 2 of the heat exchanger 1, making the temperature in the lower portion 2 of the heat exchanger 1 particularly likely to drop and condense water more easily. Furthermore, condensed water generated in the upper portion 3 of the heat exchanger 1 may flow into the lower portion 2 of the heat exchanger 1. In other words, this embodiment facilitates drainage of condensed water from each fin 31 located in the lower portion 2 of the heat exchanger 1, which is more likely to accumulate condensed water than the upper portion 3 of the heat exchanger 1.

[0032] Furthermore, in this embodiment, exposed portion 37 and bent portion 39 are provided on both sides of non-exposed portion 35 in the ventilation direction, i.e., on both the upwind side and the downwind side in the ventilation direction. Note that the upwind side in the ventilation direction is the upstream side of the flow of air passing through heat exchanger 1 along the ventilation direction, and the downwind side is the downstream side.

[0033] Condensed water adhering to the non-exposed portion 35 is likely to flow to the exposed portion 37 and the bent portion 39 located on the downwind side of the non-exposed portion 35 due to the air flow. This makes it easier to drain the condensed water via the bent portion 39 located on the downwind side of the non-exposed portion 35. Furthermore, in the heat exchanger 1, the windward ends of the flat tubes 10 are particularly susceptible to frost, and frost that forms in this area may grow and block the windward ends of the corrugated fins 30, thereby impeding the flow of air through the heat exchanger 1. In contrast, in the present embodiment, the exposed portion 37 and the bent portion 39 located on the upwind side of the non-exposed portion 35 are provided near the windward ends of the flat tubes 10. The exposed portion 37 and the bent portion 39 have a higher temperature than the flat tubes 10, which makes it easier to suppress frost growth. That is, in this embodiment, the bent portion 39 on the leeward side of the non-exposed portion 35 improves the drainage of condensed water, and the exposed portion 37 and bent portion 39 on the windward side make it easier to suppress a decrease in the heat exchange efficiency of the heat exchanger 1 due to frost formation.

[0034] [1-3. Effects, etc.] As described above, in this embodiment, the heat exchanger 1 comprises a plurality of flat tubes 10 extending in the vertical direction and arranged in parallel, and corrugated fins 30 arranged between adjacent flat tubes 10, and the corrugated fins 30 have a non-exposed portion 35 whose position in the ventilation direction overlaps with the position occupied by the flat tubes 10 in the ventilation direction, and an exposed portion 37 that protrudes further than the flat tubes 10 in the ventilation direction, and the exposed portion 37 has a bent portion 39 bent toward the adjacent flat tube 10. This allows condensed water adhering to the heat exchanger 1 to easily flow along the bent portion 39. Therefore, it is possible to provide a heat exchanger 1 that allows condensed water to be easily drained.

[0035] As in this embodiment, in the heat exchanger 1, the bent portions 39 may be configured to be more inclined vertically than the non-exposed portions . This makes it easier for the condensed water adhering to the heat exchanger 1 to flow along the bent portion 39. Therefore, it is possible to provide a heat exchanger 1 that allows condensed water to be easily drained.

[0036] As in this embodiment, the length L3 of the bent portion 39 may be equal to or greater than the distance D1 between adjacent non-exposed portions 35 of the corrugated fin 30 in the up-down direction. This allows the condensed water flowing along the bent portion 39 to easily flow directly to the next lower bent portion 39. This makes it possible to provide a heat exchanger 1 that allows condensed water to be easily drained.

[0037] As in this embodiment, in the heat exchanger 1, the dimension of the exposed portion 37 in the airflow direction may be half or less of the dimension of the flat tubes 10 in the airflow direction. This prevents the corrugated fins 30 from becoming large in size, thereby reducing manufacturing costs and providing a heat exchanger 1 that allows condensed water to be easily drained. In particular, in this embodiment, the drainage performance is improved without providing any new parts to the heat exchanger 1. This makes it possible to suppress an increase in the number of parts in the heat exchanger 1, and to suppress increases in material costs, parts management costs, and manufacturing costs, as well as decreases in productivity.

[0038] As in this embodiment, the lowermost bent portion 39 of the corrugated fin 30 may be configured to be adjacent to the lower header pipe 13 . As a result, the condensed water that has flowed along the lowest bent portion 39 can easily flow along the lower header pipe 13. Therefore, it is possible to provide a heat exchanger 1 that allows condensed water to be easily drained.

[0039] As in this embodiment, the bent portion 39 may be provided in the lower portion 2 of the heat exchanger 1. This makes it easier to drain condensed water from the lower portion 2 of the heat exchanger 1, which is particularly required to have a high drainage capacity, via the bent portion 39. Therefore, it is possible to provide a heat exchanger 1 that allows condensed water to be easily drained. In particular, in this embodiment, the fins 31 of the corrugated fins 30 located in the upper portion 3 of the heat exchanger 1 do not have the exposed portions 37 and the bent portions 39. Therefore, the exposed portions 37 and the bent portions 39 can be provided only in the lower portion 2 of the heat exchanger 1, where drainage performance is particularly important, making it easier to ensure the necessary drainage performance while minimizing the increase in size of the corrugated fins 30.

[0040] As in this embodiment, the heat exchanger 1 may be configured such that the exposed portion 37 is provided on the upwind side of the non-exposed portion 35 in the airflow direction. This can delay frost formation on the windward side of the heat exchanger 1, making it less likely that the ventilation passage of the heat exchanger 1 will be blocked. This makes it easier to prevent a decrease in the heat exchange efficiency of the heat exchanger 1. In particular, in this embodiment, exposed portion 37 and bent portion 39 are provided on the downwind side as well as on the upwind side of non-exposed portion 35. Therefore, exposed portion 37 on the upwind side makes it easier to delay frost formation on heat exchanger 1, and exposed portion 37 and bent portion 39 on the downwind side make it easier to improve drainage performance.

[0041] (Embodiment 2) Hereinafter, the second embodiment will be described with reference to the drawings. Only the differences from the first embodiment will be described below, and the description of the same configuration as the first embodiment will be omitted.

[0042] [2-1.Configuration] Fig. 5 is a perspective view of a corrugated fin 130 according to embodiment 2. Fig. 6 is a cross-sectional view of heat exchanger 101 according to embodiment 2, showing heat exchanger 101 cut along a horizontal cross section.

[0043] The heat exchanger 101 according to the second embodiment has corrugated fins 130 that are different from the corrugated fins 30 according to the first embodiment. Non-exposed portions 135 of the corrugated fins 130 according to the second embodiment are each formed in a substantially flat plate shape.

[0044] As shown in Fig. 6, in the second embodiment, exposed portion 37 and bent portion 39 are provided only on the front side of non-exposed portion 135 in the ventilation direction. In this embodiment, heat exchanger 101 is disposed in a position where air blown by a blower or the like passes through from the rear to the front. That is, in the second embodiment, exposed portion 37 and bent portion 39 are provided only on the downwind side of non-exposed portion 135 in the ventilation direction. In other words, heat exchanger 101 is disposed in a position where exposed portion 37 and bent portion 39 are located on the downwind side of non-exposed portion 135 in the ventilation direction.

[0045] The corrugated fin 130 is formed with ribs 136 that protrude upward from the upper surface of the non-exposed portion 135. The ribs 136 extend in the non-exposed portion 135 toward the bending start portion 38. The ribs 136 correspond to an example of a "water guide portion" in this embodiment.

[0046] Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. In Fig. 7, a horizontal plane H is indicated by an imaginary line. As shown in Fig. 7, in the corrugated fin 130, each non-exposed portion 135 is inclined so that the front side, on which the exposed portions 37 and the bent portions 39 are provided, is positioned downward. In other words, the non-exposed portion 135 is inclined so that the downwind side in the ventilation direction is positioned downward.

[0047] [2-2. Operation / effect] Non-exposed portion 135 is inclined downward on the side where exposed portion 37 and bent portion 39 are provided. Therefore, if condensed water adheres to exposed portion 135, the condensed water tends to flow due to gravity toward bent portion 39 on the downwind side.

[0048] Furthermore, the condensed water adhering to the non-exposed portion 135 is also carried toward the downwind side in the ventilation direction by the air passing through the heat exchanger 101 in the ventilation direction. As described above, the exposed portion 37 and the bent portion 39 are formed on the downwind side of the non-exposed portion 135 in the ventilation direction, and therefore the condensed water can easily reach the bent portion 39.

[0049] Furthermore, in this embodiment, ribs 136 extending toward bending start points 38 are formed on the upper surface of non-exposed portions 135. Therefore, when condensed water flows along non-exposed portions 135, the condensed water is more likely to flow along ribs 136 toward bending start points 38. Therefore, the condensed water is more likely to reach bending portions 39.

[0050] Condensed water that reaches the bent portion 39 is easily drained, similar to the first embodiment.

[0051] [2-3. Effects, etc.] As in this embodiment, in heat exchanger 101, corrugated fin 130 may be provided with ribs 136 that guide condensed water toward bending starting point 38, which is the starting point of bending portion 39. This allows the condensed water adhering to the corrugated fins 130 to easily flow along with the air flow to the bent portions 39. This makes it possible to provide a heat exchanger 101 that allows condensed water to be easily drained.

[0052] As in this embodiment, the non-exposed portion 135 may be configured to be inclined in the direction in which the side on which the exposed portion 37 is provided is positioned downward in the direction of airflow. This allows the condensed water adhering to the corrugated fins 130 to easily flow to the bent portions 39 by the action of gravity. Therefore, it is possible to provide a heat exchanger 101 that allows condensed water to be easily drained.

[0053] As in this embodiment, the exposed portion 37 may be provided only on the downwind side of the non-exposed portion 135 in the direction of airflow. This makes it possible to prevent the corrugated fins 130 from becoming too large, while making it easier to direct condensed water toward the bent portions 39 by utilizing the air flow passing through the heat exchanger 101. As a result, it is possible to provide a heat exchanger 101 that allows condensed water to be easily drained, while keeping manufacturing costs down.

[0054] (Embodiment 3) Hereinafter, a third embodiment will be described with reference to the drawings. In the third embodiment, a manufacturing method of the heat exchangers 1, 101 will be described using the heat exchanger 101 according to the second embodiment as an example. The manufacturing method of the heat exchanger 101 includes a fin manufacturing process, an assembly process, and a bent portion forming process.

[0055] [3-1. Manufacturing method] FIG. 8 is a plan view of the pressed metal sheet 230. In FIG. 8, the reference numerals of the parts of the corrugated fin 130 corresponding to the parts of the metal sheet 230 are indicated by phantom lines. The fin manufacturing process is a process of processing the metal sheet 230 to manufacture the corrugated fin 330. In the fin manufacturing process, slits 239 are formed in the flat metal sheet 230. The slits 239 are formed, for example, by pressing the metal sheet 230. The slits 239 are formed at positions corresponding to the exposed portions 37 of the corrugated fin 130. In this embodiment, the slits 239 have a first linear portion 239a extending along the airflow direction and a second linear portion 239b extending in a direction perpendicular to the airflow direction, i.e., in the second direction. One end of the first linear portion 239a extends to the end of the exposed portion 37 in the airflow direction. The second linear portion 239b branches into two from the other end of the first linear portion 239a. That is, the slit 239 is T-shaped.

[0056] Furthermore, ribs 136 (not shown) are formed on the flat metal sheet 230 by press working or the like. After the slits 239 and ribs 136 are formed, the metal sheet 230 is bent into a wave shape to form the corrugated fin 330. This completes the fin manufacturing process. However, the corrugated fin 330 manufactured by this fin manufacturing process differs from the corrugated fin 130 of the second embodiment only in that the bent portions 39 are not formed and the slits 239 are formed.

[0057] FIG. 9 is a cross-sectional view of the heat exchanger 301 at the end of the assembly process, showing a cross section corresponding to FIG. 6 . In the assembly process, the flat tubes 10 and the corrugated fins 330 manufactured in the fin manufacturing process are assembled to form the heat exchanger 301. In the assembly process, the corrugated fins 330 are arranged between adjacent flat tubes 10 arranged in parallel, and the corrugated fins 330 and the flat tubes 10 are fixed together. The corrugated fins 330 and the flat tubes 10 are fixed together by brazing, for example. In the assembly process, the upper header pipe 11 and the lower header pipe 13 are connected to both ends of the flat tubes 10 arranged in parallel. The heat exchanger 301 assembled upon completion of the assembly process differs from the heat exchanger 101 of the second embodiment only in that the bent portions 39 are not formed and the slits 239 are formed in the exposed portions 37.

[0058] The bent portion forming step is a step of forming bent portions 39 in the heat exchanger 301 assembled in the assembly step to produce the heat exchanger 101 of the second embodiment. That is, in the bent portion forming step, the bent portions 39 are formed by bending a part of the exposed portion 37 of each corrugated fin 330 along the slits 239. In the bent portion forming step, for example, the bent portions 39 may be formed by pressing each tooth of a comb having a tooth-like structure against each exposed portion 37 from above. By forming the bent portions 39 in each exposed portion 37, the corrugated fin 330 is processed into the corrugated fin 130 of the second embodiment, and the heat exchanger 301 is processed into the heat exchanger 101 of the second embodiment. This completes the bent portion forming step, and completes the manufacture of the heat exchanger 101 described in the second embodiment.

[0059] [3-2. Effects, etc.] As described above, the heat exchanger 301 described in this embodiment comprises a plurality of flat tubes 10 arranged in parallel and corrugated fins 330 arranged between adjacent flat tubes 10, and the corrugated fins 330 have non-exposed portions 135 whose positions in the ventilation direction overlap with the positions occupied by the flat tubes 10 in the ventilation direction, and exposed portions 37 that protrude further than the flat tubes 10 in the ventilation direction, and a slit 239 formed in the exposed portion 37 that allows the exposed portion 37 to be bent toward the flat tube 10. As a result, the bent portion 39 for draining condensed water can be formed simply by bending a part of the exposed portion 37 toward the flat tube 10 with the slit 239 as the boundary. This makes it easy to provide a heat exchanger 101 that can easily drain condensed water. In particular, in this embodiment, the slit 239 is T-shaped. Therefore, when a part of the exposed portion 37 is bent toward the flat tube 10 with the slit 239 as the boundary, two bent portions 39 can be formed in the exposed portion 37. This makes it easier to provide a heat exchanger 101 that allows condensed water to be drained more easily.

[0060] The manufacturing method of the heat exchanger 101 in this embodiment includes a step of fixing a corrugated fin 330 having a slit 239 formed between a plurality of flat tubes 10 arranged in parallel, and a step of bending a part of the corrugated fin 330 toward the flat tube 10 using the slit 239 as a boundary to form a bending portion 39. This allows a heat exchanger having a bent portion to be formed through a simple manufacturing process, making it easier to provide a heat exchanger that allows condensed water to be easily drained.

[0061] (Other embodiments) As described above, Embodiments 1 to 3 have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to these and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in Embodiments 1 to 3 above to create new embodiments. Therefore, other embodiments will be exemplified below.

[0062] In the first to third embodiments, the corrugated fins 30, 130, 330 are bent in a triangular wave shape, and two adjacent non-exposed portions 35, 135 form a substantially V-shape when viewed along the ventilation direction. However, this is merely an example. The corrugated fins 30, 130, 330 may have substantially horizontal, plate-like non-exposed portions 35, 135. Therefore, the corrugated fins 30, 130, 330 may be formed in any shape, such as a rectangular wave shape.

[0063] In the third embodiment, the slits 239 are described as being T-shaped, but this is just one example. The slits 239 are not limited to being T-shaped as long as they allow a portion of the exposed portion 37 to be bent toward 10. For example, the slits 239 may be L-shaped, and in the bent portion forming step, substantially the entire exposed portion 37 may be bent along the slit 239 to form one bent portion 39. That is, the number of bent portions 39 provided in each exposed portion 37 is not limited to two each as in the first and second embodiments, and may be one.

[0064] In the second embodiment, ribs 136 protruding upward from non-exposed portions 135 have been described as an example of a "water conducting portion," but this is merely an example. The "water conducting portion" may be any portion that guides water in non-exposed portions 135 to bending start portions 38 and makes it easier for the water to flow to bending portions 39. For example, slits extending toward bending start portions 38 may be formed as the "water conducting portion."

[0065] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0066] (Addendum) The above description of the embodiments discloses the following techniques. (Technology 1) A heat exchanger comprising a plurality of flat tubes extending in the vertical direction and arranged in parallel, and corrugated fins arranged between adjacent flat tubes, wherein the corrugated fins have non-exposed portions whose positions in the ventilation direction overlap with the positions occupied by the flat tubes in the ventilation direction, and exposed portions that protrude further than the flat tubes in the ventilation direction, and wherein the exposed portions have bent portions that are bent toward the adjacent flat tubes. This allows condensed water adhering to the heat exchanger to easily flow along the bent portion, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0067] (Technical Technique 2) The heat exchanger according to Technical Technique 1, wherein the bent portion is inclined more greatly in the vertical direction than the non-exposed portion. This allows condensed water adhering to the heat exchanger to flow more easily along the bent portion, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0068] (Technical Technique 3) The heat exchanger according to Technical Technique 1 or 2, wherein the length of the bent portion is equal to or greater than the distance between adjacent non-exposed portions of the corrugated fin in the up-down direction. This allows condensed water flowing along the bent portion to easily flow directly to the bent portion one stage below, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0069] (Technology 4) The heat exchanger according to any one of Technologies 1 to 3, wherein the dimension of the exposed portion in the airflow direction is equal to or less than half the dimension of the flat tube in the airflow direction. This prevents the corrugated fins from becoming too large, thereby reducing manufacturing costs and providing a heat exchanger that allows condensed water to be easily drained.

[0070] (Technical Aspect 5) The heat exchanger according to any one of Technical Aspects 1 to 4, wherein the corrugated fin is provided with a water guide portion that guides condensed water toward the starting point of the bent portion. This allows condensed water adhering to the corrugated fins to easily flow through the bent portions, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0071] (Technical Technique 6) The heat exchanger according to any one of Technical Techniques 1 to 5, wherein the non-exposed portion is inclined in a direction in which the side on which the exposed portion is provided is positioned downward in the direction of ventilation. This allows condensed water adhering to the corrugated fins to easily flow through the bent portions, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0072] (Technical Aspect 7) The heat exchanger according to any one of Technical Aspects 1 to 6, wherein the exposed portion is provided only on the downwind side of the non-exposed portion in the direction of airflow. This allows the condensed water to flow easily toward the bent portions by utilizing the air flow passing through the heat exchanger while preventing the corrugated fins from becoming too large, thereby providing a heat exchanger that allows condensed water to be easily drained while reducing manufacturing costs.

[0073] (Technical Aspect 8) The heat exchanger according to any one of Technical Aspects 1 to 7, wherein the bent portion at the bottom of the corrugated fin is adjacent to a header pipe. This allows the condensed water that has flowed along the bent portion at the lowest stage to easily flow down the header pipe, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0074] (Technical Aspect 9) The heat exchanger according to any one of Technical Aspects 1 to 8, wherein the bent portion is provided at a lower portion of the heat exchanger. This allows condensed water to be easily drained through the bent portion from the lower portion of the heat exchanger, which is particularly required to have a high drainage capacity, thereby providing a heat exchanger that allows condensed water to be easily drained.

[0075] (Technology 10) The heat exchanger according to any one of Technologies 1 to 6 or 8 to 9, wherein the exposed portion is provided on the upwind side of the non-exposed portion in the direction of airflow. This delays the formation of frost on the windward side of the heat exchanger, making it less likely that the ventilation passages of the heat exchanger will be blocked, and thus makes it easier to prevent a decrease in the heat exchange efficiency of the heat exchanger.

[0076] (Technology 11) A heat exchanger comprising a plurality of flat tubes arranged in parallel and corrugated fins arranged between adjacent flat tubes, wherein the corrugated fins have non-exposed portions whose positions in the ventilation direction overlap with the positions occupied by the flat tubes in the ventilation direction, and exposed portions that protrude further than the flat tubes in the ventilation direction, and wherein slits are formed in the exposed portions that allow the exposed portions to be bent toward the flat tubes. This allows the bent portion for draining condensed water to be formed simply by bending the exposed portion toward the flat tube at the boundary of the slit, making it easier to provide a heat exchanger that allows condensed water to be easily drained.

[0077] (Technology 12) A method for manufacturing a heat exchanger, comprising the steps of: fixing a corrugated fin having a slit formed therein between a plurality of flat tubes arranged in parallel; and bending the corrugated fin toward the flat tubes using the slit as a boundary to form a bent portion. This allows a heat exchanger having a bent portion to be formed through a simple manufacturing process, making it easier to provide a heat exchanger that allows condensed water to be easily drained. [Industrial Applicability]

[0078] The present disclosure is applicable to a heat exchanger and a manufacturing method thereof. Specifically, the present disclosure is applicable to a heat exchanger that functions as an evaporator in the refrigeration cycle of an air conditioner, a refrigerator, etc., and a manufacturing method thereof. [Explanation of symbols]

[0079] 1 heat exchanger 2. Lower 3. Upper part 10 flat tube 11 Upper header pipe 13 Lower header pipe 30 Corrugated Fin 31 Finn 33 Bend 35 Non-exposed part 37 Exposed part 38 Bending start point (starting point of bending part) 39 Bending section 101 Heat exchanger 130 Corrugated Fin 135 Non-exposed part 136 Ribs 230 Sheet Metal 239 Slit 239a 1st straight section 239b 2nd straight section 301 Heat exchanger 330 Corrugated Fin D1 interval H horizontal plane L1 dimension L2 dimension L3 length

Claims

1. a plurality of flat tubes extending in the vertical direction and arranged in parallel; and corrugated fins arranged between adjacent flat tubes, The corrugated fin is a non-exposed portion whose position in the ventilation direction overlaps with a position occupied by the flat tube in the ventilation direction; an exposed portion protruding from the flat tube in the ventilation direction, The exposed portion has a bent portion bent toward the adjacent flat tube. A heat exchanger characterized by:

2. The bent portion is inclined more greatly toward the vertical direction than the non-exposed portion.

2. The heat exchanger according to claim 1.

3. The length of the bent portion is equal to or greater than the distance between adjacent non-exposed portions of the corrugated fin in the up-down direction.

2. The heat exchanger according to claim 1.

4. The dimension of the exposed portion in the ventilation direction is half or less of the dimension of the flat tube in the ventilation direction. The heat exchanger of claim 1 .

5. The corrugated fin is provided with a water guide portion that guides condensed water toward the starting point of the bent portion. The heat exchanger of claim 1 .

6. the non-exposed portion is inclined in a direction in which the side on which the exposed portion is provided is positioned downward in the airflow direction. The heat exchanger of claim 1 .

7. The exposed portion is provided only on the downwind side of the non-exposed portion in the airflow direction. The heat exchanger of claim 1 .

8. The bent portion at the lowest stage of the corrugated fin is adjacent to a header pipe. The heat exchanger of claim 1 .

9. The bent portion is provided at a lower portion of the heat exchanger. The heat exchanger of claim 1 .

10. The exposed portion is provided on the windward side of the non-exposed portion in the airflow direction. The heat exchanger of claim 1 .

11. A plurality of flat tubes arranged in parallel; and corrugated fins arranged between adjacent flat tubes, The corrugated fin is a non-exposed portion whose position in the ventilation direction overlaps with a position occupied by the flat tube in the ventilation direction; an exposed portion protruding from the flat tube in the ventilation direction, A slit is formed in the exposed portion to enable bending of the exposed portion toward the flat tube. A heat exchanger characterized by:

12. a step of fixing a corrugated fin having slits formed therein between a plurality of flat tubes arranged in parallel; and bending the corrugated fin toward the flat tube using the slit as a boundary to form a bent portion. A method for manufacturing a heat exchanger.

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