JP7764787B2 - Stacked Heat Exchanger - Google Patents

Description

This disclosure relates to a stacked heat exchanger.

Conventionally, fin-and-tube heat exchangers have been known that have multiple plate-shaped fins arranged parallel to one another and refrigerant pipes inserted into insertion holes provided in each fin (see, for example, Patent Document 1). In these fin-and-tube heat exchangers, the refrigerant pipes are inserted into the insertion holes of the fins and joined to the fins with adhesive. These fin-and-tube heat exchangers exchange heat between the refrigerant flowing through the refrigerant pipes and the air by flowing a fluid such as air between the multiple fins.

Since heat exchangers are required to have the greatest possible heat transfer performance, Patent Document 1 describes a method for joining refrigerant pipes and fins that compensates for the reduced heat transfer performance caused by using adhesive. Specifically, the method describes a refrigerant pipe with adhesive applied to approximately half of its surface being inserted into an insertion hole and joined, thereby creating direct contact between the surface of the refrigerant pipe and the inner surface of the fin insertion hole, thereby improving the heat transfer performance of the heat exchanger. The method also describes a joining method in which multiple grooves for applying adhesive are created on the surface of the refrigerant pipe, and the refrigerant pipe and fin are joined using adhesive filled in the grooves, thereby improving the heat transfer performance of the heat exchanger by creating direct contact between the surface of the refrigerant pipe other than the grooves and the inner surface of the insertion hole.

JP 2016-044841 A

Heat exchangers that use fins have configurations other than fin-and-tube heat exchangers, such as stacked heat exchangers, which alternately stack multiple flat, plate-like plates and fins made by bending thin plate members back and forth in a corrugated pattern. In stacked heat exchangers, adjacent plates form flow paths through which fluid flows, and these plates function as flow path forming sections.

In addition, in a stacked heat exchanger, corrugated fins are provided in the flow path section, and one side of the fins in the plate thickness direction is joined to the flow path forming section. Therefore, in order to ensure heat exchange efficiency, which indicates the heat transfer performance of a stacked heat exchanger, the method of joining the corrugated fins to the flow path forming section, which forms the flow path section through which the fluid flows, is important.

However, Patent Document 1 only describes a method for joining refrigerant tubes and fins that can improve the heat exchange efficiency of a fin-and-tube heat exchanger, and does not describe a method for joining flow path forming sections and fins that can improve the heat exchange efficiency of a stacked heat exchanger.

The purpose of this disclosure is to provide a stacked heat exchanger that can improve heat exchange efficiency.

The invention described in claim 1 is
A stacked heat exchanger,
a plurality of flow path forming portions (20, P) that form flow path portions (AP, RP, WP) through which a fluid flows;
fins (10, 60, IF) joined to the flow path forming portion by an adhesive (G);
The fin is formed by bending a plate-like member into a wave-like shape, and a plurality of tip portions (11, 61) joined to the flow path forming portion and extension portions (12, 62) extending so as to connect adjacent tip portions are alternately arranged, and at least a part of the tip portions is in direct contact with the flow path forming portion without using an adhesive;
The flow path forming portion has a joining surface (21, 22) to which the tip portion is joined,
the joining surface extends in a plane and has guide grooves (70, 71, 72, 73, 74, 75) for guiding adhesive to the portion where the flow path forming portion and the fin are joined;
The guide groove guides the adhesive to the periphery of a portion of the tip portion that directly contacts the flow path forming portion, and when the direction in which the plurality of tip portions and the plurality of extension portions are alternately arranged is defined as the fin extension direction (DR1s, DR2s), the guide groove includes a first guide groove (71) that extends at an angle with respect to the fin extension direction and a second guide groove (72) that is at an angle with respect to the fin extension direction and extends intersecting the direction in which the first guide groove extends,
The first guide groove and the second guide groove intersect with each other at a portion of the joining surface where the tip portion is disposed.

As a result, at least a portion of the tip of the fin is in direct contact with the flow path forming portion without the use of adhesive, which reduces the decrease in thermal conductivity between the fin and the flow path forming portion that occurs when joining with adhesive, thereby improving the heat exchange efficiency of the stacked heat exchanger.

The invention described in claim 3 is as follows:
A stacked heat exchanger,
a plurality of flow path forming portions (20, P) that form flow path portions (AP, RP, WP) through which a fluid flows;
fins (10, 60, IF) joined to the flow path forming portion by an adhesive (G);
The flow path forming portion has a joining surface (21, 22) to which the tip portion is joined,
the joining portion extends in a plane and has guide grooves (70, 71, 72, 73, 74, 75) for guiding adhesive to a portion where the flow path forming portion and the fin are joined;
The fin is formed by bending a plate-like member into a wave-like shape, and a plurality of tip portions (11, 61) joined to the flow path forming portion and extension portions (12, 62) extending so as to connect adjacent tip portions are formed alternately, and at least a part of the tip portions is in contact with the flow path forming portion via a thin film adhesive,
The guide groove guides adhesive to the periphery of the portion that contacts the flow path forming portion via a thin film of adhesive at the tip portion , and includes a first guide groove (71) that extends at an angle to the fin extension direction (DR1s, DR2s) when the direction in which the plurality of tip portions and the plurality of extension portions are alternately arranged is defined as the fin extension direction, and a second guide groove (72) that is at an angle to the fin extension direction and extends intersecting the direction in which the first guide groove extends,
The first guide groove and the second guide groove intersect with each other at a portion of the joining surface where the tip portion is disposed.

Accordingly, even if adhesive is present on at least a portion of the tip of the fin, as long as the adhesive is in the form of a thin film, there is almost no impact from the decrease in thermal conductivity between the fin and the flow path forming portion that occurs when bonding with adhesive. This makes it possible to suppress the decrease in thermal conductivity between the fin and the flow path forming portion that occurs when bonding with adhesive, thereby improving the heat exchange efficiency of the stacked heat exchanger.

In addition, the thin film adhesive provided between the tip and the flow path forming portion is guided by the guide groove so that the film thickness is approximately constant. This reduces variations in thermal conductivity between the fin and the flow path forming portion caused by variations in the film thickness of the thin film adhesive.

Note that the reference symbols in parentheses attached to each component indicate an example of the correspondence between that component and the specific components described in the embodiments described below.

FIG. 1 is a perspective view of a heat exchanger according to a first embodiment. FIG. 2 is an enlarged view of a portion II in FIG. 1 . 3 is a side view of the tube and the first fin as viewed from the direction of the arrow indicated by III in FIG. 2. FIG. 4 is a side view of the tube and the first fin as viewed from the direction of the arrow indicated by IV in FIG. 2. FIG. FIG. 2 is an enlarged view of a portion V in FIG. 1 . FIG. 2 is a cross-sectional view of the tube according to the first embodiment. 5A to 5C are diagrams illustrating a method for joining a first fin and a tube according to the first embodiment. FIG. 8 is a cross-sectional view of part VIII of FIG. 7. FIG. 9 is a cross-sectional view of part IX of FIG. 7. 8 is a side view of the first fin and the tube as viewed from the direction of the arrow indicated by X in FIG. 7 . FIG. 10 is a diagram showing a guide groove according to a first modified example of the first embodiment. FIG. 10 is a diagram showing a guide groove according to a second modified example of the first embodiment. FIG. 10 is a diagram showing a guide groove according to a third modified example of the first embodiment. FIG. 14 is a cross-sectional view of a portion XIV of FIG. 13. FIG. 10 is a diagram corresponding to FIG. 9 in the second embodiment. FIG. 10 is a view corresponding to FIG. 9 in the third embodiment. FIG. 10 is a view corresponding to FIG. 9 in the fourth embodiment. FIG. 10 is a view corresponding to FIG. 9 in the fifth embodiment. FIG. 12 is a view corresponding to FIG. 10 in the sixth embodiment. FIG. 10 is a perspective view of a heat exchanger according to another embodiment. FIG. 21 is a cross-sectional view of a portion XXI of FIG. 20 . FIG. 22 is an enlarged view of a portion XXII of FIG. 21. FIG. 10 is a view corresponding to FIG. 8 of another embodiment.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that in the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, when only some of the components are described in an embodiment, the components described in the preceding embodiment can be applied to the remaining components. The following embodiments can be partially combined with each other, as long as there is no particular problem with the combination, even if not specifically stated.

(First embodiment)
This embodiment will be described with reference to Figures 1 to 10. The heat exchanger 1 of this embodiment is used, for example, as an evaporator that constitutes part of a refrigeration cycle that conditions the air inside a vehicle. The evaporator exchanges heat between a refrigerant circulating in the refrigeration cycle and air passing through the heat exchanger 1, and cools the air using the latent heat of evaporation of the refrigerant.

As shown in FIG. 1, the heat exchanger 1 includes a plurality of first fins 10, a plurality of tubes 20, a first header tank 31, a second header tank 32, a third header tank 33, a fourth header tank 34, and an outer frame member 40. These members are formed from a material (e.g., a metal such as aluminum) with a higher thermal conductivity than the adhesive G (described below) used to join the tubes 20 and the first fins 10. Note that these members are not limited to aluminum and may be formed from a metal other than aluminum, or may be formed from a material other than metal, such as a resin with high conductivity.

The multiple tubes 20 are stacked and arranged at predetermined intervals in a direction intersecting the air flow direction. That is, the heat exchanger 1 of this embodiment is a stacked heat exchanger in which multiple tubes 20 are stacked and arranged, and is a fin-tube heat exchanger. The multiple tubes 20 are arranged in two rows, one upstream and one downstream in the air flow direction. Each of the multiple tubes 20 extends linearly from one end to the other. One end of each of the multiple tubes 20 is inserted into the first header tank 31 or the second header tank 32, and the other end is inserted into the third header tank 33 or the fourth header tank 34.

The first header tank 31 and the second header tank 32 distribute the refrigerant to the multiple tubes 20. The third header tank 33 and the fourth header tank 34 collect the refrigerant flowing in from the multiple tubes 20. Note that the tubes 20 are not limited to a structure with two rows in the air flow direction, and may be a structure with only one row in the air flow direction.

As shown in Figures 2 and 3, the gaps formed between adjacent tubes 20 in the stacking direction among the multiple tubes 20 form air passages AP as flow paths through which air, a fluid, flows. The first fins 10 are provided in the air passages AP. Specifically, the first fins 10 are bonded to the flat surface of the tubes 20. That is, the first fins 10 in this embodiment are outer fins provided on the outside of the tubes 20. Hereinafter, the surface of the tube 20 will also be referred to as the outer peripheral surface 21. The outer peripheral surface 21 of the tube 20 has guide grooves 70, described below, formed therein to guide adhesive G to the area where the tube 20 and the first fin 10 are bonded.

As shown in Figures 4 to 6, the tube 20 has a cross-sectional shape that is a flat tube. The tube 20 is formed by bending a single metal plate into a tubular shape and then overlapping and joining portions of the metal plate's surface. As a result, a refrigerant passage RP is formed inside the tube 20 as a flow path through which a refrigerant fluid flows. The tube 20 has second fins 60 in the refrigerant passage RP. Specifically, the second fins 60 are joined to the flat inner surface of the tube 20. In other words, the second fins 60 in this embodiment are inner fins provided inside the tube 20. Hereinafter, the inner surface of the tube 20 is also referred to as the inner surface 22. Grooves (not shown) are formed in the inner surface 22 of the tube 20 to guide adhesive G to the area where the tube 20 and the second fin 60 are joined. In this embodiment, the tube 20 functions as a flow path forming portion that forms the air passage AP and the refrigerant passage RP, which are flow path portions.

The first fins 10 increase the heat transfer area between the refrigerant flowing inside the tubes 20 and the air flowing outside the tubes 20, thereby improving the heat exchange efficiency between the refrigerant and the air. The first fins 10 are so-called corrugated fins formed by bending a thin metal plate member made of aluminum or other material into a wave-like shape. The first fins 10 have multiple first tip portions 11 and first extension portions 12. The multiple first tip portions 11 are portions where the plate member constituting the first fin 10 is bent at predetermined intervals. The first tip portions 11 have an arc-shaped cross section perpendicular to the air flow direction, and are curved so as to bulge toward the tubes 20.

The first extension portion 12 is a portion of the multiple first tip portions 11 that is located between adjacent first tip portions 11. The first extension portion 12 is formed to extend in a plane so as to connect adjacent first tip portions 11.

As shown in Figures 4 and 5, the first extension section 12 is provided with a plurality of louvers 14 formed by cutting and raising portions of a plate-like member. The first tip sections 11 contact the outer peripheral surfaces 21 of adjacent tubes 20, and these contacting portions are joined with adhesive G. In other words, the outer peripheral surfaces 21 are the joining surfaces to which the first tip sections 11 are joined. This joining structure secures the first fins 10 to the tubes 20. Details of the method for joining the first fins 10 to the tubes 20 will be described later.

In the following, as shown in Figure 2 and other figures, the thickness direction of the first fin 10 is referred to as the first fin thickness direction DR1t, and the direction in which the corrugated fin extends is referred to as the first fin extension direction DR1s. Furthermore, the direction perpendicular to the first fin thickness direction DR1t and the first fin extension direction DR1s is referred to as the first fin width direction DR1w. The first fin thickness direction DR1t is the direction in which the waves in the corrugated first fin 10 travel back and forth, and corresponds to the fin thickness direction. The first fin extension direction DR1s is the direction in which the multiple first tip portions 11 and multiple first extension portions 12 are alternately arranged, and corresponds to the fin extension direction. The first fin width direction DR1w corresponds to the fin width direction.

The first fins 10 are arranged so that the first fin thickness direction DR1t is the stacking direction of the tubes 20 and the first fin extension direction DR1s is the longitudinal direction of the tubes 20. Furthermore, the first fins 10 are arranged so that the first fin width direction DR1w is the air flow direction in the air passage AP. In other words, the first fin extension direction DR1s coincides with the longitudinal extension direction of the outer peripheral surface 21 of the tubes 20. Furthermore, the first fin width direction DR1w coincides with the width direction of the tubes 20.

The second fin 60 is a so-called corrugated fin formed by bending a thin metal plate member made of aluminum or the like into a wave-like shape. The second fin 60 has multiple second tip portions 61 and multiple second extension portions 62. The multiple second tip portions 61 are portions where the plate member constituting the second fin 60 is bent at predetermined intervals. The second tip portions 61 have an arc-shaped cross section perpendicular to the refrigerant flow direction, and are curved so as to bulge toward the inner circumferential surface 22 of the tube 20.

The second extension portion 62 is a portion of the multiple second tip portions 61 that is located between adjacent second tip portions 61. The second extension portion 62 is formed to extend in a plane so as to connect the adjacent second tip portions 61.

The second tip 61 of the second fin 60 contacts the inner circumferential surface 22 of the tube 20, and the contacting portion is bonded with adhesive G. In other words, the inner circumferential surface 22 is the bonding surface to which the second tip 61 is bonded. This bonding structure secures the second fin 60 to the tube 20. The method for bonding the second fin 60 to the tube 20 is the same as the method for bonding the first fin 10 to the tube 20, and details of this bonding method will be described later in the section on the method for bonding the first fin 10 to the tube 20.

In the following, as shown in Figure 6 and other figures, the thickness direction of the second fin 60 is referred to as the second fin thickness direction DR2t, and the direction in which the corrugated fin extends is referred to as the second fin extension direction DR2s. Furthermore, the direction perpendicular to the second fin thickness direction DR2t and the second fin extension direction DR2s is referred to as the second fin width direction DR2w. The second fin thickness direction DR2t is the direction in which the waves in the corrugated second fin 60 travel back and forth, and corresponds to the fin thickness direction. The second fin extension direction DR2s is the direction in which the multiple second tip portions 61 and multiple second extension portions 62 are alternately arranged, and corresponds to the fin extension direction. The second fin width direction DR2w corresponds to the fin width direction.

The second fins 60 are arranged so that the second fin thickness direction DR2t is the stacking direction of the tubes 20 and coincides with the first fin thickness direction DR1t. The second fins 60 are also arranged so that the second fin extension direction DR2s is the width direction of the tubes 20 and coincides with the first fin width direction DR1w. The second fins 60 are also arranged so that the second fin width direction DR2w is the refrigerant flow direction in the refrigerant passage RP and coincides with the first fin extension direction DR1s.

An outer frame member 40 is provided on the outside in the direction in which the multiple tubes 20 and multiple first fins 10 are alternately arranged. A piping connection member (not shown) is fixed to the outer frame member 40. The refrigerant has a refrigerant inlet through which refrigerant is supplied and a refrigerant outlet through which the refrigerant is discharged. The refrigerant flows into the first header tank 31 from the refrigerant inlet of the piping connection member, flows through the first header tank 31 to the fourth header tank 34 and the multiple tubes 20 along a predetermined path, and flows out from the refrigerant outlet of the piping connection member. At this time, the latent heat of vaporization of the refrigerant flowing through the first header tank 31 to the fourth header tank 34 and the multiple tubes 20 cools the air flowing through the air passage AP in which the first fins 10 are provided.

Next, a method for joining the first fin 10 and the tube 20 will be described with reference to Figures 7 to 10. As shown in Figure 7, the first fin 10 is joined by adhesive G applied to the outer peripheral surface 21 of the tube 20 at a location where the first fin 10 will be located. Specifically, the first tip 11 of the first fin 10 on one side in the first fin thickness direction DR1t is joined to the tube 20 by adhesive G applied to the outer peripheral surface 21 of the tube 20 located on one side of the first fin 10 in the first fin thickness direction DR1t. Furthermore, the first tip 11 of the first fin 10 on the other side in the first fin thickness direction DR1t is joined to the tube 20 by adhesive G applied to the outer peripheral surface 21 of the tube 20 located on the other side of the first fin 10 in the first fin thickness direction DR1t.

The method for joining one side of the first fin 10 in the first fin thickness direction DR1t to the tube 20 is the same as the method for joining the other side of the first fin 10 in the first fin thickness direction DR1t to the tube 20. Therefore, in this embodiment, only the details of the method for joining one side of the first fin 10 in the first fin thickness direction DR1t to the tube 20 will be described, and details of the method for joining the other side of the first fin 10 in the first fin thickness direction DR1t to the tube 20 will be omitted.

When joining the first fin 10 and the tube 20, adhesive G for joining the first fin 10 is placed in a guide groove 70 formed on the outer surface 21 of the tube 20. The depth of the guide groove 70 is, for example, 1 mm. However, the depth of the guide groove 70 is not limited, and the depth of the guide groove 70 may be greater or less than 1 mm.

Then, with adhesive G placed in the guide groove 70, the first tip 11 of the first fin 10 is placed on the outer surface 21 of the tube 20, thereby joining the first fin 10 and the tube 20. In this embodiment, the adhesive G is a resin material that has adhesive properties and contains a filler mixed in to enhance thermal conductivity.

Note that Figure 7 shows only a portion of the first fin 10, with other portions omitted. Also, in Figures 7 to 10, the adhesive G is hatched with a dotted pattern to make it easier to see.

Here, as shown in FIG. 7 , in this embodiment, multiple guide grooves 70 are formed on the outer peripheral surface 21 of the tube 20. The guide grooves 70 are formed linearly along the outer peripheral surface 21. The guide grooves 70 extend at an angle in the first fin extension direction DR1s and the first fin width direction DR1w. Specifically, the guide grooves 70 include a first guide groove 71 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w. The guide grooves 70 also include a second guide groove 72 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w and intersects the direction in which the first guide groove 71 extends.

A plurality of first guide grooves 71 are formed in a line along the first fin extension direction DR1s. Furthermore, each first guide groove 71 has a rectangular cross-sectional shape in a plane perpendicular to the direction in which the first guide groove 71 extends. Each first guide groove 71 is formed across one or more first fins 10.

A plurality of second guide grooves 72 are formed in a row along the first fin width direction DR1w. The cross section of the second guide grooves 72 perpendicular to the direction in which the second guide grooves 72 extend is rectangular. The second guide grooves 72 are formed across one or more first fins 10.

The cross-sectional shape of the plane perpendicular to the direction in which the first guide groove 71 and the second guide groove 72 extend is not limited to a rectangular shape, but may be, for example, an arc shape or a V shape.

The first guide groove 71 and the second guide groove 72 are formed over the entire outer peripheral surface 21 of the tube 20 and intersect with each other. That is, the first guide groove 71 and the second guide groove 72 are formed in a grid pattern. The first tip 11 of the first fin 10 is joined at the location where the first guide groove 71 and the second guide groove 72 intersect with each other. In other words, the first guide groove 71 and the second guide groove 72 are formed so as to intersect with each other at the location on the outer peripheral surface 21 of the tube 20 where the first tip 11 is located.

For this reason, the portions of the outer peripheral surface 21 of the tube 20 where the first fins 10 are arranged alternate along the first fin width direction DR1w between portions where the first guide grooves 71 and second guide grooves 72 intersect and portions where the first guide grooves 71 and second guide grooves 72 are not formed. The cross section shown in Figure 8 is perpendicular to the first fin width direction DR1w and shows a cross section of a portion where the first guide grooves 71 and second guide grooves 72 intersect. In contrast, the cross section shown in Figure 9 is perpendicular to the first fin width direction DR1w and shows a cross section of a portion where the first guide grooves 71 and second guide grooves 72 are not formed.

When the first fin 10 and the tube 20 are joined, the adhesive G used to bond the first fin 10 to the tube 20 is filled into the first guide groove 71 and the second guide groove 72 formed in this manner. When the adhesive G is filled into the first guide groove 71 and the second guide groove 72, it flows and spreads inside the first guide groove 71 and the second guide groove 72. Furthermore, the adhesive G is guided along the first guide groove 71 and the second guide groove 72 by the surface tension generated on its surface. Therefore, the adhesive G that is guided and filled into the first guide groove 71 and the second guide groove 72 is arranged so that the size in the depth direction of the groove is approximately uniform. In other words, the adhesive G that is guided and filled into the first guide groove 71 and the second guide groove 72 is arranged so that the film thickness is approximately constant. In this embodiment, the entire space formed by the first guide groove 71 and the second guide groove 72 is filled with adhesive G.

The first fin 10 is bonded to the outer peripheral surface 21 of the tube 20 by the adhesive G disposed in the first guide groove 71 and the second guide groove 72. The portion of the first tip portion 11 of the first fin 10 facing the outer peripheral surface 21 of the tube 20, opposite the portion where the first guide groove 71 and the second guide groove 72 are formed, contacts the outer peripheral surface 21 of the tube 20 via the adhesive G. In contrast, the portion of the first tip portion 11 of the first fin 10 facing the outer peripheral surface 21 of the tube 20, opposite the portion where the first guide groove 71 and the second guide groove 72 are not formed, contacts the outer peripheral surface 21 of the tube 20 directly without the adhesive G. In other words, a portion of the first fin 10 directly contacts the tube 20 without the adhesive G.

Hereinafter, the portion of the first tip portion 11 that directly contacts the tube 20 will be referred to as the direct contact portion 11a, and the portion that does not directly contact the tube 20 but indirectly contacts the tube 20 via the adhesive G will be referred to as the indirect contact portion 11b.

Here, as shown in Figures 8 to 10, a fillet F is formed at the joint between the first fin 10 and the tube 20 using adhesive G. The fillet F is formed on one side and the other side of the first tip portion 11 in the first fin extension direction DR1s. Specifically, the fillet F is formed on one side and the other side of the direct contact portion 11a and the indirect contact portion 11b in the first fin extension direction DR1s.

This fillet F is formed when the adhesive G is drawn up toward the first tip 11 by capillary force that occurs when the first fin 10 is joined to the outer surface 21 of the tube 20. Therefore, the size of the fillet F in the first fin plate thickness direction DR1t decreases with increasing distance from the first tip 11, like the foot of a mountain.

The fillets F formed on one side of the indirect contact portion 11b in the first fin extension direction DR1s and the other side of the first fin extension direction DR1s are connected via adhesive G filled in the first guide groove 71 and the second guide groove 72, as shown in FIG. 8. Therefore, the surface tensions of the fillets F formed on one side of the indirect contact portion 11b in the first fin extension direction DR1s and the fillets F formed on the other side of the first fin extension direction DR1s are approximately equal. Therefore, the fillets F formed on one side of the indirect contact portion 11b in the first fin extension direction DR1s and the fillets F formed on the other side of the first fin extension direction DR1s have approximately the same size in the first fin thickness direction DR1t. Hereinafter, the size of the fillet F in the first fin thickness direction DR1t is also referred to as the fillet height Fh.

Furthermore, the fillet F formed on one side of the indirect contact portion 11b in the first fin extension direction DR1s extends to the ends of the first guide groove 71 and the second guide groove 72 on one side in the first fin extension direction DR1s. The fillet F formed on the other side of the indirect contact portion 11b in the first fin extension direction DR1s extends to the ends of the first guide groove 71 and the second guide groove 72 on the other side in the first fin extension direction DR1s.

For this reason, the size of the first fin width direction DR1w of the fillet F formed on one side and the other side of the indirect contact portion 11b in the first fin extension direction DR1s can be set by the size of the first fin extension direction DR1s of the first guide groove 71 and the second guide groove 72. In this embodiment, the size of the first fin extension direction DR1s of the first guide groove 71 and the second guide groove 72 is formed to a size that ensures sufficient joining force when joining the first fin 10 and the tube 20. Hereinafter, the size of the fillet F in the first fin extension direction DR1s is also referred to as the fillet width Fw.

As shown in FIG. 9 , the fillets F formed on one side of the direct contact portion 11a in the first fin extension direction DR1s and the other side of the first fin extension direction DR1s are not directly connected. However, as shown in FIG. 10 , the fillet F formed on the other side of the direct contact portion 11a in the first fin extension direction DR1s is connected to the fillet F formed on the other side of the indirect contact portion 11b in the first fin extension direction DR1s. Furthermore, although not shown, the fillet F formed on one side of the direct contact portion 11a in the first fin extension direction DR1s is connected to the fillet F formed on one side of the indirect contact portion 11b in the first fin extension direction DR1s. As a result, the fillet F formed on one side of the direct contact portion 11a in the first fin extension direction DR1s and the fillet F formed on the other side of the first fin extension direction DR1s are connected via the adhesive G disposed in the first guide groove 71 and the second guide groove 72.

As a result, the surface tensions of the fillets F formed on one side of the direct contact portion 11a in the first fin extension direction DR1s and the fillets F formed on the other side of the first fin extension direction DR1s are approximately equal. Therefore, the fillets F formed on one side of the direct contact portion 11a in the first fin extension direction DR1s and the fillets F formed on the other side of the first fin extension direction DR1s are approximately equal. Furthermore, the fillets F formed on one side of the direct contact portion 11a in the first fin extension direction DR1s have approximately the same fillet width Fw as the fillets F formed on one side of the indirect contact portion 11b in the first fin extension direction DR1s. Furthermore, the fillets F formed on the other side of the direct contact portion 11a in the first fin extension direction DR1s have approximately the same fillet width Fw as the fillets F formed on the other side of the indirect contact portion 11b in the first fin extension direction DR1s.

For this reason, the fillets F formed on one side and the other side of the direct contact portion 11a in the first fin extension direction DR1s can also be set by the size of the first guide groove 71 and the second guide groove 72 in the first fin extension direction DR1s.

As described above, the fillet F formed between the first tip portion 11 of the first fin 10 and the outer surface 21 of the tube 20 more firmly bonds the first fin 10 and the tube 20.

Although detailed description will be omitted, the second fin 60 and the tube 20 are joined using the same joining method as the first fin 10 and the tube 20. That is, the second tip end 61 of the second fin 60 on one side in the second fin thickness direction DR2t is joined to the inner surface 22 of the tube 20 by adhesive G applied to the inner surface 22 of the tube 20 located on one side of the second fin 60 in the second fin thickness direction DR2t. Furthermore, the second tip end 61 of the second fin 60 on the other side in the second fin thickness direction DR2t is joined to the inner surface 22 of the tube 20 by adhesive G applied to the inner surface 22 of the tube 20 located on the other side of the second fin 60 in the second fin thickness direction DR2t.

Grooves (not shown) for filling with adhesive G are formed on the inner circumferential surface 22 of the tube 20, and adhesive G is filled into these grooves for bonding the second fin 60. These grooves are formed in a grid pattern, similar to the first guide grooves 71 and second guide grooves 72 formed on the outer circumferential surface 21 of the tube 20. That is, the grooves formed on the inner circumferential surface 22 have first grooves that extend at an angle in the second fin extension direction DR2s and the second fin width direction DR2w. The grooves formed on the inner circumferential surface 22 also have second grooves that extend at an angle in the second fin extension direction DR2s and the second fin width direction DR2w and intersect the direction in which the first grooves extend.

The second fin 60 is bonded to the inner circumferential surface 22 of the tube 20 by adhesive G filled in the first and second grooves thus formed. The second tip 61 of the second fin 60, at the portion facing the inner circumferential surface 22 of the tube 20 opposite the portion where the first and second grooves are formed, contacts the tube 20 via adhesive G. In contrast, the second tip 61 of the second fin 60, at the portion facing the inner circumferential surface 22 of the tube 20 opposite the portion where the first and second grooves are not formed, contacts the inner circumferential surface 22 of the tube 20 directly without adhesive G. In other words, a portion of the second tip 61 directly contacts the tube 20 without adhesive G. Furthermore, at the joint between the second fin 60 and the inner circumferential surface 22 of the tube 20, fillets F are formed on both sides of the second tip 61 in the second fin extension direction DR2s.

As described above, portions of the first fins 10 and second fins 60 are in direct contact with the tubes 20 without the adhesive G. The thermal conductivity of the adhesive resin material contained in the adhesive G is approximately 1/100 to 1/1000 lower than that of the first fins 10 and second fins 60, which are made of metal. Therefore, joining the first fins 10 and second fins 60 to the tubes 20 using adhesive G reduces the thermal conductivity during heat exchange between the first fins 10 and second fins 60 and the tubes 20. Furthermore, reduced thermal conductivity between the first fins 10 and second fins 60 and the tubes 20 reduces the heat exchange efficiency during heat exchange between the refrigerant circulating in the refrigeration cycle and the air passing through the heat exchanger 1.

In contrast, in the first fin 10 of this embodiment, a portion of the first tip portion 11 is in direct contact with the outer surface 21 of the tube 20 without the adhesive G. This prevents a decrease in thermal conductivity between the first fin 10 and the tube 20 that occurs when they are joined using the adhesive G.

In addition, a portion of the second tip portion 61 of the second fin 60 is in direct contact with the inner surface 22 of the tube 20 without the adhesive G. This prevents a decrease in thermal conductivity between the second fin 60 and the tube 20 that occurs when joining them with the adhesive G. This improves the heat exchange efficiency of the heat exchanger 1.

Furthermore, a portion of the first tip 11 of the first fin 10 is in direct contact with the outer peripheral surface 21 of the tube 20 without the adhesive G interposed therebetween. Furthermore, a portion of the second tip 61 of the second fin 60 is in direct contact with the inner peripheral surface 22 of the tube 20 without the adhesive G interposed therebetween. As a result, the amount of adhesive G can be reduced compared to a configuration in which adhesive G is provided so that the entire first tip 11 and the entire second tip 61 each contact the tube 20 via adhesive G.

In addition, the adhesive G in this embodiment contains a filler to increase thermal conductivity. However, mixing a filler into the adhesive G reduces the adhesiveness of the adhesive G.

In contrast, the heat exchanger 1 of this embodiment is configured so that portions of the first fins 10 and second fins 60 directly contact the tubes 20 without the adhesive G, as described above, thereby improving the heat exchange efficiency of the heat exchanger 1. Therefore, even if the filler content is reduced compared to when this configuration is not used, it is possible to ensure heat exchange efficiency while also ensuring adhesion between the first fins 10 and second fins 60 and the tubes 20.

Furthermore, the above embodiment can achieve the following effects:

(1) In the above embodiment, the tube 20 has an outer peripheral surface 21 to which the first tip portion 11 is joined. The outer peripheral surface 21 extends flat and is formed with a first guide groove 71 and a second guide groove 72 that guide adhesive G to the area where the tube 20 and the first fin 10 are joined. The first guide groove 71 and the second guide groove 72 guide adhesive G to the periphery of the area of the first tip portion 11 that directly contacts the tube 20.

As a result, when adhesive G is placed on the outer surface 21 of the tube 20, the adhesive G is guided into the first guide groove 71 and the second guide groove 72. This makes it easier to place adhesive G around the first tip 11, ensuring a reliable bond between the outer surface 21 of the tube 20 and the first fin 10.

Furthermore, when the tube 20 and the first fin 10 are connected with adhesive G, a fillet F is formed at the joint between the tube 20 and the first fin 10. Like the foot of a mountain, the fillet height Fh of this fillet F decreases with increasing distance from the first tip 11, and it is formed up to the ends of the first guide groove 71 and the second guide groove 72. The smaller the fillet width Fw of the fillet F formed at the joint between the tube 20 and the first fin 10, the lower the bond between the tube 20 and the first fin 10.

In contrast, the fillet width Fw of the fillet F is set by the size of the first fin extension direction DR1s of the first guide groove 71 and the second guide groove 72. The size of the first fin extension direction DR1s of the first guide groove 71 and the second guide groove 72 is formed to a size that ensures sufficient joining force when joining the first fin 10 and the tube 20. This allows for reliable joining of the tube 20 and the first fin 10.

(2) In the above embodiment, the first guide groove 71 extends at an angle with respect to the first fin extension direction DR1s.

This ensures that a portion of the first fin 10 comes into direct contact with the tube 20 even if the positions of the tube 20 and the first fin 10 shift from their designed positions in the first fin extension direction DR1s when joining the tube 20 and the first fin 10. In other words, compared to forming the first guide groove 71 and the second guide groove 72 only in the portion facing the first tip portion 11, the first guide groove 71 and the second guide groove 72 can be easily formed on the outer surface 21 of the tube 20 without requiring high design precision.

(3) In the above embodiment, the outer peripheral surface 21 is formed with a first guide groove 71 that extends at an angle relative to the first fin width direction DR1w, and a second guide groove 72 that extends at an angle relative to the first fin width direction DR1w and intersects the direction in which the first guide groove 71 extends.

This allows the tube 20 and the first fin 10 to be bonded together using the adhesive G filled in the first guide groove 71 and the second guide groove 72. This increases the area over which the tube 20 and the first fin 10 come into contact with the adhesive G compared to when only one of the first guide groove 71 and the second guide groove 72 is formed on the outer peripheral surface 21. This allows the tube 20 and the first fin 10 to be reliably bonded together.

(First Modification of the First Embodiment)
In the first embodiment described above, the guide groove 70 includes a first guide groove 71 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w. The guide groove 70 also includes a second guide groove 72 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w and intersects with the direction in which the first guide groove 71 extends. However, the guide groove 70 is not limited to this configuration.

For example, the guide groove 70 may be configured with only one of the first guide groove 71 and the second guide groove 72 extending at an angle in the first fin extension direction DR1s and the first fin width direction DR1w. For example, as shown in FIG. 11 , the first guide groove 71 may be eliminated compared to the first embodiment, and only the second guide groove 72 may be included. Alternatively, although not shown, the second guide groove 72 may be eliminated compared to the first embodiment, and only the first guide groove 71 may be included.

(Second Modification of the First Embodiment)
In the first embodiment described above, the guide groove 70 includes a first guide groove 71 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w. The guide groove 70 also includes a second guide groove 72 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w and intersects with the direction in which the first guide groove 71 extends. However, the guide groove 70 is not limited to this configuration.

For example, the guide groove 70 may include a third guide groove 73 extending along the first fin extension direction DR1s, as shown in FIG. 12.

(Third Modification of the First Embodiment)
In the first embodiment described above, the guide groove 70 includes a first guide groove 71 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w. The guide groove 70 also includes a second guide groove 72 that extends at an angle in the first fin extension direction DR1s and the first fin width direction DR1w and intersects with the direction in which the first guide groove 71 extends. However, the guide groove 70 is not limited to this configuration.

For example, as shown in Figures 13 and 14, the guide groove 70 may include a fourth guide groove 74 and a fifth guide groove 75 extending along the first fin width direction DR1w. The fourth guide groove 74 is formed on one side of the outer peripheral surface 21 of the tube 20 in the first fin extension direction DR1s at a portion facing the first tip end 11. The fifth guide groove 75 is formed on the other side of the outer peripheral surface 21 of the tube 20 in the first fin extension direction DR1s at a portion facing the first tip end 11.

By forming the fourth guide groove 74 and the fifth guide groove 75 in a location on the outer surface 21 of the tube 20 that is different from the location facing the first tip 11, the entire tip of the first fin 10 can be in direct contact with the tube 20. Therefore, compared to a configuration in which only a portion of the tip of the first fin 10 is in direct contact with the tube 20, the decrease in thermal conductivity that occurs when bonding with adhesive G is suppressed, thereby improving the heat exchange efficiency of the heat exchanger 1.

(Fourth Modification of the First Embodiment)
In the first embodiment described above, an example has been described in which the first guide groove 71 and the second guide groove 72 are formed across one or more first fins 10, but the present invention is not limited to this.

For example, the first guide groove 71 and the second guide groove 72 may be configured to span only one first fin 10. In this case, the first guide groove 71 and the second guide groove 72 may be configured to be formed in each portion of the outer surface 21 of the tube 20 that faces each of the multiple first tip portions 11.

(Fifth Modification of the First Embodiment)
In the above-described first embodiment, an example was described in which the first guide groove 71 and the second guide groove 72 are formed so as to intersect with each other at the portion of the outer surface 21 of the tube 20 where the first tip portion 11 is located, but this is not limited to this.

For example, the first guide groove 71 and the second guide groove 72 may be formed to intersect with each other at a portion of the outer surface 21 of the tube 20 where the first tip portion 11 is not located.

Second Embodiment
Next, a second embodiment will be described with reference to Fig. 15. This embodiment differs from the first embodiment in that not all of the first tip portions 11 of the first fins 10 are in direct contact with the tubes 20. The rest of the second embodiment is the same as the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar portions to the first embodiment may be omitted.

As shown in FIG. 15 , in the heat exchanger 1 of this embodiment, a small amount of adhesive G is interposed between the first fin 10 and the tube 20. That is, the entire first tip portion 11 of this embodiment does not directly contact the outer peripheral surface 21, and does not include the direct contact portion 11a of the first embodiment. A portion of the first tip portion 11 of the first fin 10 contacts the tube 20 via a thin film of adhesive G. Here, the adhesive G disposed between the first fin 10 and the tube 20 has a gradient in which the magnitude of the first fin thickness direction DR1t gradually decreases toward the tip of the first fin 10. The thin film of adhesive G is located in the portion of the adhesive G disposed between the first fin 10 and the tube 20 where the magnitude of the first fin thickness direction DR1t is smallest. In other words, the thin film of adhesive G is located in the portion of the adhesive G disposed between the first fin 10 and the tube 20 where the distance between the first fin 10 and the outer peripheral surface 21 of the tube 20 is smallest. In Figure 15, to make the thin-film adhesive G easier to see, the areas where the thin-film adhesive G is formed are shown with dotted lines.

The reason why a thin film of adhesive G is present between the first fin 10 and the tube 20 will be explained below. The first fin 10 and the tube 20 are bonded together by adhesive G disposed in the first guide groove 71 and the second guide groove 72. At this time, the adhesive G disposed in the first guide groove 71 and the second guide groove 72 is sucked up toward the first tip 11 by capillary force. For this reason, when the first fin 10 and the tube 20 are bonded together, a small amount of adhesive G may be present between the first fin 10 and the tube 20. This results in a thin film of adhesive G being provided between the first tip 11 and the outer circumferential surface 21.

The thickness of the thin film of adhesive G formed in this manner is much smaller than the thickness of the fillet F. The thickness of the thin film of adhesive G is smaller than the size of the first guide groove 71 and the second guide groove 72 in the first fin thickness direction DR1t (i.e., the size of the first guide groove 71 and the second guide groove 72 in the depth direction). The thickness of the thin film of adhesive G may be 1/5 or 1/10 or less of the size of the first guide groove 71 and the second guide groove 72 in the first fin thickness direction DR1t. In this embodiment, the thickness of the thin film of adhesive G is 50 μm or less. When such a thin film of adhesive G is interposed between the first fin 10 and the tube 20, the presence of the adhesive G hardly affects the reduction in thermal conductivity between the first fin 10 and the tube 20. In other words, the reduction in thermal conductivity between the first fin 10 and the tube 20 when the thin film of adhesive G is interposed between the first fin 10 and the tube 20 is negligibly small. In other words, even if a thin film of adhesive G is present between the first fin 10 and the tube 20, the first fin 10 and the tube 20 can be considered to be in substantial direct contact.

In addition, if the reduction in thermal conductivity between the first fin 10 and the tube 20 when the thin film of adhesive G is interposed between the first fin 10 and the tube 20 is negligibly small, the thickness of the thin film of adhesive G may be greater than 50 μm, such as 100 μm.

The rest of the configuration is the same as in the first embodiment described above. Therefore, the same effects as in the first embodiment can be obtained from a configuration similar to or equivalent to that of the first embodiment.

Furthermore, similar to the configuration in which a portion of the first tip portion 11 directly contacts the tube 20, it is possible to suppress the decrease in thermal conductivity that occurs when bonding with adhesive G. Therefore, even in the configuration in which a portion of the first tip portion 11 contacts the tube 20 via a thin film of adhesive G, it is possible to improve the heat exchange efficiency of the heat exchanger 1 to the same extent as in the configuration of the first embodiment.

The thin film adhesive G provided between the first tip portion 11 and the outer peripheral surface 21 is guided and positioned along the tip of the first tip portion 11. Therefore, the thin film adhesive G provided between the first tip portion 11 and the outer peripheral surface 21 is formed so that its thickness is approximately constant. This makes it possible to suppress variations in the thermal conductivity between the first fin 10 and the tube 20 caused by variations in the thickness of the thin film adhesive G.

In this embodiment, an example in which a thin film of adhesive G is formed between the first fin 10 and the tube 20 has been described, but a thin film of adhesive G may also be formed between the second fin 60 and the tube 20. Even in this case, the heat exchange efficiency of the heat exchanger 1 can be improved to the same extent as in the configuration of the first embodiment, just as in the case in which a thin film of adhesive G is formed between the first fin 10 and the tube 20.

(Third embodiment)
Next, a third embodiment will be described with reference to Fig. 16. In this embodiment, the first guide groove 71 and the second guide groove 72 are eliminated, and the shape of the first tip portion 11 of the first fin 10 differs from that of the first embodiment. Other than this, the third embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar portions to the first embodiment may be omitted.

As shown in FIG. 16, the first tip portion 11 of this embodiment has one protrusion 11c at its tip that protrudes toward the tube 20. The protrusion 11c is formed so that the portion of the first tip portion 11 of the first fin 10 that is curved and bulges toward the tube 20, closest to the tube 20, bulges further toward the tube 20. Furthermore, the protrusion 11c extends along the first fin width direction DR1w at the tip of the first tip portion 11 and is formed in a semi-cylindrical shape. The cross section of the protrusion 11c perpendicular to the air flow direction has an arc-shaped cross section.

In this embodiment, the protrusion 11c directly contacts the outer surface 21 of the tube 20 without the adhesive G. In contrast, the portions of the protrusion 11c on one side and the other side of the first fin extension direction DR1s at the first tip portion 11 contact the outer surface 21 of the tube 20 via the adhesive G.

The cross-sectional shape of the protrusion 11c perpendicular to the air flow direction is not limited to an arc shape, but may be rectangular or triangular, for example.

The rest of the configuration is the same as in the first embodiment described above. Therefore, the same effects as in the first embodiment can be obtained from a configuration similar to or equivalent to that of the first embodiment.

Furthermore, by configuring the first tip portion 11 to have the protrusion 11c, the space between the first tip portion 11 and the tube 20 is larger than in a configuration without the protrusion 11c. This allows for a larger amount of adhesive G between the first tip portion 11 and the tube 20, ensuring that the first fin 10 is securely bonded to the tube 20 using the adhesive G.

In this embodiment, an example in which a protrusion 11c is provided on the first tip 11 of the first fin 10 has been described, but a protrusion 11c may also be formed on the second tip 61 of the second fin 60. Even in this case, the second fin 60 can be reliably joined to the tube 20 by the adhesive G, just as in the case in which a protrusion 11c is provided on the first tip 11.

(First Modification of the Third Embodiment)
In the third embodiment described above, an example has been described in which one protrusion 11c that protrudes toward the tube 20 is provided at the tip of the first tip portion 11, but this is not limiting. For example, a plurality of protrusions 11c may be provided at the first tip portion 11.

(Second Modification of the Third Embodiment)
In the third embodiment described above, an example has been described in which a portion of the protrusion 11c directly contacts the outer circumferential surface 21 of the tube 20 without the adhesive G interposed therebetween, but the present invention is not limited to this. For example, the protrusion 11c may be configured to contact the tube 20 via a thin film of adhesive G, as described in the second embodiment.

(Third Modification of the Third Embodiment)
In the third embodiment described above, the protrusion 11c extends in the first fin width direction DR1w at the tip of the first tip portion 11 and is formed in a semi-cylindrical shape. However, the present invention is not limited to this. For example, the protrusion 11c may be hemispherical and multiple protrusions 11c may be formed in the first fin width direction DR1w.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to Fig. 17. In this embodiment, the first guide groove 71 and the second guide groove 72 are eliminated, and the shape of the first tip portion 11 of the first fin 10 differs from that of the first embodiment. Other than this, the fourth embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar portions to the first embodiment may be omitted.

As shown in FIG. 17 , the first tip portion 11 of this embodiment has one recess 11d formed at the tip thereof, recessed on the side opposite the outer peripheral surface 21 of the tube 20. The recess 11d is formed by curving the edge of the first tip portion 11 of the first fin 10 in the first fin extension direction DR1s so that it recesses toward the center of the first fin 10 in the first fin thickness direction DR1t. In other words, the recess 11d is formed by recessing on the side opposite the side joined to the tube 20. The cross section of the recess 11d perpendicular to the air flow direction has an arc-shaped shape. The recess 11d is formed to penetrate along the first fin width direction DR1w.

The first tip portion 11 having such a recess 11d has a W-shaped cross section perpendicular to the first fin width direction DR1w, i.e., the air flow direction in the air passage AP. In other words, the first tip portion 11 has a shape in which one side and the other side of the recess 11d in the first fin extension direction DR1s protrude toward the tube 20.

The first tip portion 11 has portions on one side and the other side of the recess 11d that protrudes toward the tube 20 in the first fin extension direction DR1s that come into direct contact with the outer surface 21 of the tube 20 without the adhesive G interposed therebetween.

In addition, adhesive G is placed in the space formed between the recess 11d and the tube 20. As a result, the recess 11d of the first tip portion 11 comes into contact with the outer surface 21 of the tube 20 via the adhesive G.

The cross-sectional shape of the recess 11d perpendicular to the air flow direction is not limited to an arc shape, but may be rectangular or V-shaped, for example.

The first fin 10, which includes the first tip portion 11 having the recess 11d, is bonded to the tube 20 by adhesive G placed in the recess 11d.

The rest of the configuration is the same as in the first embodiment described above. Therefore, the same effects as in the first embodiment can be obtained from a configuration similar to or equivalent to that of the first embodiment.

Furthermore, by configuring the first tip portion 11 to have the recess 11d, the contact area between the first tip portion 11 and the adhesive G can be made larger compared to a configuration without the recess 11d. This allows the first fin 10 to be reliably bonded to the tube 20 by the adhesive G.

In this embodiment, an example has been described in which a recess 11d is provided in the first tip 11 of the first fin 10, but a recess 11d may also be formed in the second tip 61 of the second fin 60. Even in this case, the second fin 60 can be reliably joined to the tube 20 by the adhesive G, just as in the case in which a recess 11d is provided in the first tip 11.

(Modification of the Fourth Embodiment)
In the above-described fourth embodiment, an example has been described in which the portions of the recess 11d on one side and the other side in the first fin extension direction DR1s are in direct contact with the outer circumferential surface 21 of the tube 20 without the adhesive G. However, the present invention is not limited to this. For example, the portions of the recess 11d on one side and the other side in the first fin extension direction DR1s may be configured to be in contact with the tube 20 via a thin film of adhesive G, as described in the second embodiment.

Fifth Embodiment
Next, a fifth embodiment will be described with reference to Fig. 18. In this embodiment, the shape of the first tip portion 11 of the first fin 10 is different from that of the fourth embodiment. The rest of the fifth embodiment is the same as the fourth embodiment. Therefore, in this embodiment, differences from the fourth embodiment will be mainly described, and descriptions of similar parts to the fourth embodiment may be omitted.

The first fin 10 of this embodiment is formed by bending a plate-like material into a wave shape, and has a straight portion 11e at the first tip portion 11, which is the tip of the wave-shaped plate-like material, that extends in a plane along the outer peripheral surface 21 of the tube 20, as shown in FIG. 20. The straight portion 11e is formed in a plane along the first fin extension direction DR1s and the first fin width direction DR1w. The straight portion 11e has multiple recesses 11d formed on the side opposite the outer peripheral surface 21 of the tube 20. Each of the multiple recesses 11d is formed to be curved so as to be recessed toward the center of the first fin 10 in the first fin plate thickness direction DR1t.

The first tip portion 11, which has multiple recesses 11d, has a cross-sectional shape perpendicular to the air flow direction that has multiple recesses and protrusions. In other words, the cross-sectional shape of the first tip portion 11 perpendicular to the air flow direction has a shape in which multiple recesses 11d and multiple protrusions 11f are alternately arranged along the first fin extension direction DR1s in the straight portion 11e. The protrusions 11f are portions that protrude toward the outer surface 21 of the tube 20 compared to the recesses 11d.

The first tip portion 11 has a protruding portion 11f that protrudes toward the tube 20 and comes into direct contact with the outer surface 21 of the tube 20 without the adhesive G. In contrast, the recessed portion 11d comes into contact with the outer surface 21 of the tube 20 via the adhesive G.

The first fin 10, which includes the first tip portion 11 having the recess 11d, is bonded to the tube 20 by adhesive G placed in the recess 11d.

The rest of the configuration is the same as in the fourth embodiment described above. Therefore, the same effects as in the fourth embodiment can be obtained from a configuration similar to or equivalent to that of the fourth embodiment.

Furthermore, compared to a configuration in which only one recess 11d is provided, it is easier to increase the contact area between the first tip portion 11 and the adhesive G. This allows the first fin 10 to be reliably bonded to the tube 20 using the adhesive G.

In this embodiment, an example has been described in which multiple recesses 11d and multiple protrusions 11f are provided in the straight portion 11e of the first tip portion 11 of the first fin 10. However, if the second tip portion 61 of the second fin 60 has a similar straight portion 11e, multiple recesses 11d and multiple protrusions 11f may be formed in the straight portion 11e. Even in this case, the second fin 60 can be reliably bonded to the tube 20 with adhesive G, just as in the case in which recesses 11d are provided in the first tip portion 11.

(Modification of the Fifth Embodiment)
In the above-described fifth embodiment, an example has been described in which the protrusion 11f directly contacts the outer circumferential surface 21 of the tube 20 without the adhesive G therebetween, but the present invention is not limited to this. For example, the protrusion 11f may be configured to contact the tube 20 via a thin film of adhesive G, as described in the second embodiment.

Sixth Embodiment
Next, a sixth embodiment will be described with reference to FIG. 19 . In this embodiment, the shape of the recess 11d is different from that of the fourth embodiment. Other than this, the sixth embodiment is similar to the fourth embodiment. Therefore, in this embodiment, differences from the fourth embodiment will be mainly described, and descriptions of similar parts to the fourth embodiment may be omitted.

As shown in Figure 19, in this embodiment, multiple recesses 11d are formed along the first fin width direction DR1w. The recesses 11d are formed to penetrate the first tip portion 11 along the first fin extension direction DR1s, and the cross section in the first fin extension direction DR1s has an arc-shaped shape.

The first tip portion 11 thus has multiple recesses 11d, and is shaped so that multiple recesses 11d and multiple protrusions 11f are arranged alternately along the first fin width direction DR1w. The protrusions 11f protrude more toward the outer surface 21 of the tube 20 than the recesses 11d.

The first tip portion 11 has a protruding portion 11f that protrudes toward the tube 20 and comes into direct contact with the outer surface 21 of the tube 20 without the adhesive G. In contrast, the recessed portion 11d comes into contact with the outer surface 21 of the tube 20 via the adhesive G.

The first fin 10, which includes the first tip portion 11 having the recess 11d, is bonded to the tube 20 by adhesive G placed in the recess 11d.

The rest of the configuration is the same as in the fourth embodiment described above. Therefore, the same effects as in the fourth embodiment can be obtained from a configuration similar to or equivalent to that of the fourth embodiment.

Furthermore, compared to a configuration in which only one recess 11d is provided, it is easier to increase the contact area between the first tip portion 11 and the adhesive G. This allows the first fin 10 to be reliably bonded to the tube 20 using the adhesive G.

In this embodiment, an example has been described in which multiple recesses 11d are provided in the first tip portion 11 of the first fin 10. However, the second fin 60 is configured to have multiple recesses 11d in the second tip portion 61. Even in this case, the second fin 60 can be reliably bonded to the tube 20 with adhesive G, just as in the case in which recesses 11d are provided in the first tip portion 11.

(Modification of the Sixth Embodiment)
In the sixth embodiment described above, an example has been described in which the protrusion 11f directly contacts the outer circumferential surface 21 of the tube 20 without the adhesive G interposed therebetween, but the present invention is not limited to this. For example, the protrusion 11f may be configured to contact the tube 20 via a thin film of adhesive G, as described in the second embodiment.

(Other embodiments)
Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

In the above-described embodiment, the heat exchanger 1 is a fin-tube heat exchanger in which the tubes 20 are stacked. However, this is not limiting. For example, the heat exchanger 1 may be a fin-plate heat exchanger in which multiple plates P are stacked, as shown in Figures 20 to 22. When the heat exchanger 1 is a fin-plate heat exchanger, refrigerant passages RP and cooling water flows WP, through which cooling water flows as a fluid, are alternately formed in the stacking direction in the gaps between the multiple plates P. Inner fins IF are provided between adjacent plates P in the stacking direction. The inner fins IF are bonded with adhesive G to the plate P on one side of the stacking direction and the plate P on the other side of the stacking direction. When the heat exchanger 1 is a fin-plate heat exchanger, the plates P function as flow path forming portions that define the flow path portions.

The plate P and inner fin IF can be joined using the same method as used to join the tubes 20 and first fins 10 described in the above embodiments. This reduces the decrease in thermal conductivity between the plate P and inner fin IF that occurs when joining them with adhesive G, improving the heat exchange efficiency of the heat exchanger 1. The fins arranged in this heat exchanger 1 may be offset fins, as shown in FIG. 22, in which thin metal plate members made of aluminum or other materials are bent into a wave shape and adjacent cut-and-raised portions are offset from each other in the air flow direction.

In the above embodiment, an example was described in which the entire space formed by the first guide groove 71 and the second guide groove 72 was filled with adhesive G, but this is not limited to this. For example, adhesive G may be filled only in part of the space formed by the first guide groove 71 and the second guide groove 72.

In the above-described embodiment, an example was described in which the heat exchanger 1, which is a fin-tube heat exchanger, has second fins 60 inside the tubes 20, but this is not limited to this. For example, the heat exchanger 1, which is a fin-tube heat exchanger, may be configured not to have second fins 60 inside the tubes 20.

In the above-described first and second embodiments, examples have been described in which guide grooves 70 are formed on the outer peripheral surface 21 and inner peripheral surface 22 of the tube 20, but this is not limiting. For example, a configuration in which guide grooves 70 are not formed on the outer peripheral surface 21 and inner peripheral surface 22 of the tube 20 may also be used.

In the third to sixth embodiments described above, examples were described in which the guide grooves 70 were not formed on the outer peripheral surface 21 and inner peripheral surface 22 of the tube 20, but this is not limiting. For example, the guide grooves 70 may be formed on the outer peripheral surface 21 and inner peripheral surface 22 of the tube 20.

It goes without saying that in the above-described embodiments, the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

In the above-described embodiments, when numerical values such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to those specific numbers unless expressly stated as essential or unless they are clearly limited to a specific number in principle.

In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., there is no limitation to those shapes, positional relationships, etc., unless otherwise specified or in principle limited to specific shapes, positional relationships, etc.

10, 60 Fin 11 Tip portion 12 Extension portion 20 Flow path forming portion 70 Guide groove AP, RP Flow path portion G Adhesive

Claims (5)

A stacked heat exchanger,
a plurality of flow path forming portions (20, P) that form flow path portions (AP, RP, WP) through which a fluid flows;
a fin (10, 60, IF) joined to the flow path forming portion by an adhesive (G),
The fin is formed by bending a plate-like member into a wave-like shape, and a plurality of tip portions (11, 61) joined to the flow path forming portion and extension portions (12, 62) extending so as to connect the adjacent tip portions are alternately arranged, and at least a part of the tip portions is in direct contact with the flow path forming portion without the adhesive therebetween,
The flow path forming portion has a joining surface (21, 22) to which the tip portion is joined,
the joining surface extends in a plane and has guide grooves (70, 71, 72, 73, 74, 75) that guide the adhesive to the area where the flow path forming portion and the fin are joined,
The guide groove guides the adhesive to the periphery of a portion of the tip portion that directly contacts the flow path forming portion, and when a direction in which the plurality of tip portions and the plurality of extension portions are alternately arranged is defined as a fin extension direction (DR1s, DR2s), the guide groove includes a first guide groove (71) that extends at an angle with respect to the fin extension direction and a second guide groove (72) that is at an angle with respect to the fin extension direction and extends intersecting the direction in which the first guide groove extends,
The first guide groove and the second guide groove intersect with each other at a portion of the joint surface where the tip end portion is disposed . A stacked heat exchanger,
a plurality of flow path forming portions (20, P) that form flow path portions (AP, RP, WP) through which a fluid flows;
a fin (10, 60, IF) joined to the flow path forming portion by an adhesive (G),
The fin is formed by bending a plate-like member into a wave-like shape, and a plurality of tip portions (11, 61) joined to the flow path forming portion and extension portions (12, 62) extending so as to connect the tip portions adjacent to each other are formed alternately, and at least a part of the tip portions contacts the flow path forming portion via the thin film-like adhesive,
The flow path forming portion has a joining surface (21, 22) to which the tip portion is joined,
the joining surface extends in a plane and has guide grooves (70, 71, 72, 73, 74, 75) that guide the adhesive to the area where the flow path forming portion and the fin are joined,
The guide groove guides the adhesive through a thin film of the adhesive at the tip end portion to the periphery of the portion that contacts the flow path forming portion , and when a direction in which the tip end portions and the extension portions are alternately arranged is defined as a fin extension direction (DR1s, DR2s), the guide groove includes a first guide groove (71) that extends at an angle with respect to the fin extension direction and a second guide groove (72) that is at an angle with respect to the fin extension direction and extends intersecting the direction in which the first guide groove extends,
The first guide groove and the second guide groove intersect with each other at a portion of the joint surface where the tip end portion is disposed . The tip portion has a protruding portion (11c) that protrudes toward the flow path forming portion,
3. The stacked heat exchanger according to claim 1, wherein the fins are bonded to the flow passage forming portion by the adhesive disposed around the protrusions. The tip portion has a recess (11d) formed by being recessed on the side opposite to the side joined to the flow path forming portion,
4. A stacked heat exchanger according to claim 1, wherein the fins are bonded to the flow path forming portion by the adhesive disposed around the tip portion and the adhesive disposed in the recess portion. The tip portion has a straight portion (11e) extending in a plane along a surface of the flow path forming portion on the side where the tip portion is joined,
The stacked heat exchanger according to claim 4 , wherein a plurality of the recesses are formed in the straight portion.