heat exchanger

Abstract

The present invention provides a heat exchanger that enables control of the flow of brazing material in the header tank of the heat exchanger, thereby suppressing the occurrence of brazing defects. [Solution] The heat exchanger 1 comprises a header tank 3 having a cylindrical body 30 and a cap 33 that closes the opening at the end of the cylindrical body 30. The cylindrical body 30 is made up of a first member 31 and a second member 32, and includes a single-layer region 301 consisting only of the first member 31 or the second member 32, and a double-layer region 302 formed by stacking the first member 31 and the second member 32. The cap 33 has a bent portion BN at its edge 33T that continuously covers the single-layer region 301 and the double-layer region 302 around the opening, and an inclined surface SL is provided on the outer surface of the cylindrical body 30 near the bent portion BN, which is inclined in the direction of the bent portion BN.

Description

Technical Field

[0001] The present invention relates to a heat exchanger.

Background Art

[0002] Conventionally, in a vehicle air conditioner using a heat pump cycle, a plurality of heat exchangers are used in a refrigerant circuit. These plurality of heat exchangers include, for example, a heat exchanger disposed in an HVAC (Heating, Ventilating, and Air Conditioning) unit having an air flow passage through which air in the vehicle interior flows, and a heat exchanger (outdoor heat exchanger) disposed outside the vehicle. The outdoor heat exchanger has, for example, a plurality of tubes arranged in parallel and tanks connected to both ends (upper and lower ends) thereof, and some function as a radiator during cooling and as a heat absorber during heating.

[0003] The tanks of the outdoor heat exchanger are formed, for example, by facing a first tank member and a second tank member each formed in a substantially concave shape so as to close each other's openings, and joining, for example, a part of the side surface of the first tank member and a part of the side surface of the second tank member to form a cylindrical tank. Both ends of the cylindrical tank are closed with caps (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional heat exchanger, there has been a problem that poor brazing of the header tank is likely to occur during assembly.

[0006] Let's explain this in detail with reference to Figure 8. Figure 8 shows an example of a conventional heat exchanger 500, where Figure 8(A) is an overall side view, Figure 8(B) is an enlarged perspective view of the dashed rectangle portion in Figure 8(A), and Figure 8(C) is an enlarged view of the dashed rectangle portion in Figure 8(B).

[0007] The heat exchanger 500 consists of multiple tubes 501 arranged in the depth direction of Figure 8(A), with header tanks 503 and 504 connected to both ends of the tubes 501 in the longitudinal direction (up and down direction in Figure 8(A)). The header tanks 503 and 504 have a similar configuration and extend in the depth direction of Figure 8(A).

[0008] As shown in Figure 8(B), for example, the header tank 503 is constructed by combining two tank members (first tank member 531 and second tank member 532) that are roughly U-shaped in side view, with a portion of their sides overlapping to form a cylindrical body, and closing the openings at both ends with caps 533.

[0009] In this case, as shown in Figures 8(B) and 8(C), the cylindrical body has a single-layer region 503A consisting of only one of the first tank member 531 and the second tank member 532, and a double-layer region 503B where both members 531 and 532 overlap. In the example in Figure 8, the double-layer region 503B is the region where parts of the sides of both members 531 and 532 overlap, and the remaining region is the single-layer region 503A.

[0010] Furthermore, the cap 533 is, for example, a cover lid having an edge portion 534 that covers the perimeter of the opening, and the edge portion 534 is provided with a bent portion BN at a position corresponding to the stepped portion between the single-layer region 503A and the double-layer region 503B of the cylindrical body, so that they are continuously covered.

[0011] In this case, as shown in Figure 8(C), a boundary exists between the single-layer region 503A and the double-layer region 503B facing the outer bend radius R of the bent portion BN, and a roughly triangular prism-shaped gap G is created between them along the bend line of the bent portion BN. In particular, when the heat exchanger 500 is large, and the plate thickness of the tank members 531, 532 and the cap 533 is thick, the outer bend radius becomes larger, and as a result, the gap G also becomes larger.

[0012] Brazing material is applied to the inner surface of the cap 533 (right side in Figure 8(C)) and the outer surfaces of the first tank member 531 and the second tank member 532 (left side in Figure 8(C)). When brazing is performed, the material melts, filling the gap G, and fixing the first tank member 531, the second tank member 532, and the cap 533 together.

[0013] However, one end of the roughly triangular prism-shaped gap G (the end corresponding to the bottom of the triangular prism) is covered by the cap 533, while the other end is in communication with the outside. Therefore, it was difficult to control the flow of molten brazing material in the gap G. As a result, if the brazing material flows uncontrollably, for example, and flows out of the gap G to the outside, there is a risk of brazing defects occurring in and around the gap G due to a shortage of brazing material.

[0014] This invention has been made in view of the above problems, and provides a heat exchanger that enables control of the flow of brazing material in the header tank of the heat exchanger and can suppress the occurrence of brazing defects. [Means for solving the problem]

[0015] The present invention relates to a heat exchanger comprising a cylindrical body and a header tank having a cap that closes the opening at the end of the cylindrical body, wherein the cylindrical body is made up of a combination of a first member and a second member, and includes a single-layer region consisting only of the first member or the second member, and a double-layer region formed by stacking the first member and the second member, the cap has a bent portion at its edge that continuously covers the single-layer region and the double-layer region around the opening, and the outer surface of the cylindrical body near the bent portion is provided with an inclined surface that extends from the center in the longitudinal direction of the cylindrical body toward the bent portion. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a heat exchanger that enables control of the flow of brazing material in the header tank of the heat exchanger and suppresses the occurrence of brazing defects.

Brief Description of the Drawings

[0017] [Figure 1] It is an external perspective view of a heat exchanger according to an embodiment of the present invention. [Figure 2] It is a perspective view showing a first example of a header tank according to an embodiment of the present invention. [Figure 3] It is a view showing a first example of a header tank according to an embodiment of the present invention, and is a cross-sectional view at an end portion. [Figure 4] It is a view showing a first example of a header tank according to an embodiment of the present invention, (A) an exploded perspective view of an end portion, (B) a perspective view of an end portion, (C) an exploded side view of an end portion. [Figure 5] It is a front view of an end portion showing a first example of a header tank according to an embodiment of the present invention [Figure 6] It is a view showing a second example of a header tank according to an embodiment of the present invention, (A) an exploded perspective view of an end portion, (B) an exploded side view of an end portion. [Figure 7] It is a front view of an end portion showing a second example of a header tank according to an embodiment of the present invention [Figure 8] It is a view showing a conventional heat exchanger.

Modes for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIGS. 1 to 7 are an example of embodiments of the present invention. In the figures, parts denoted by the same reference numerals indicate parts having the same function or the same components, and duplicate explanations in each figure are omitted as appropriate.

[0019] <Heat Exchanger> FIG. 1 is a schematic perspective view showing an example of the heat exchanger 1 of the present embodiment. The heat exchanger 1 includes a plurality of tubes 2 arranged in parallel and header tanks 3 and 4 connected to both ends of the plurality of tubes 2 in the extending direction. Note that FIG. 1 is a schematic view, and the header tanks 3 and 4 have the configurations shown in FIGS. 2 and later in detail. The heat exchanger 1 performs heat exchange between, for example, a heat medium flowing through the tube 2 via the header tanks 3 and 4 and a fluid (for example, air) passing between the plurality of tubes 2. In the present embodiment, as an example, a configuration is adopted in which a heat medium flows through the tube 2, but a refrigerant may flow therein.

[0020] In the illustrated example, the tube 2 is a tubular body extending in one direction (the direction of the arrow X (Xa - Xb) in the figure) and having a flat shape along the direction (the direction of the arrow Z (Za - Zb) in the figure) intersecting the extending direction. The tubes 2 are arranged in parallel at predetermined intervals in the direction (the direction of the arrow Y (Ya - Yb) in the figure) intersecting the extending direction, and the space between the plurality of tubes 2 becomes a passage for the fluid to be heat-exchanged. The fluid to be heat-exchanged flows in the direction of the arrow Z in the figure and performs heat exchange with the heat medium flowing through the tube 2 while passing between the plurality of tubes 2. In the space between the plurality of tubes 2, fins (for example, corrugated fins), which are generally omitted in the figure, are provided to enhance the heat exchange efficiency.

[0021] In the following description, the direction of the arrow X in FIG. 1 is referred to as the tube extending direction, the direction of the arrow Y as the header tank longitudinal direction (or simply the longitudinal direction), and the direction of the arrow Z as the header tank short-side direction (or simply the short-side direction).

[0022] The header tanks 3 and 4 are provided at both ends in the tube extending direction (X direction). One header tank 3 is formed into a cylindrical shape by coupling a first tank member 31 and a second tank member 32, and both end portions in the header tank longitudinal direction (the direction of the arrow Y in the figure) are closed with caps 33, thereby forming a space in which the heat medium flows inside.

[0023] The other header tank 4 is formed by joining the first tank member 41 and the second tank member 42 to form a cylindrical shape, and both ends in the longitudinal direction of the header tank (direction Y indicated by arrow) are sealed with caps 43, thereby creating a space inside through which a heat transfer medium flows.

[0024] In the example shown in Figure 1, the header tank 3 has an inlet 6 in the first tank member 31, and the second tank member 32 is connected to one end in the direction of tube extension (upper in Figure 1, Xa side). The header tank 4 has an outlet 7 in the first tank member 41, and the second tank member 42 is connected to the other end in the direction of tube extension (lower in Figure 1, Xb side).

[0025] In this configuration, the heat transfer medium flowing in from the inlet 6 flows through the upper header tank 3 to the tube 2, and the heat transfer medium flowing through the tube 2 flows through the lower header tank 4 and is discharged from the outlet 7.

[0026] Multiple tubes 2 are arranged longitudinally along the header tank, and a pair of side plates 5 are provided at both ends. The pair of side plates 5 define the spacing between the header tanks 3 and 4, and the multiple tubes 2 arranged inside them form a heat exchange core.

[0027] Conventionally, it was difficult to control the flow of molten brazing material in the lateral sections S1 and S2 facing each other in the short direction (Z direction) of header tanks 3 and 4 in Figure 1, which could lead to poor brazing due to insufficient brazing material. In this embodiment, it is possible to control the flow of brazing material in the lateral sections S1 and S2, enabling good brazing of header tanks 3 and 4. The configurations of header tanks 3 and 4 are the same below, so the details will be explained using header tank 3 as an example.

[0028] <First example> Figures 2 to 5 show the header tank 3 of the first example. Figure 2 is a perspective view showing the entire header tank 3, and Figure 3 is a cross-section of line XX in Figure 2, and an enlarged view of a part thereof (the dashed circle). Figure 4 is an enlarged view of the Ya side end in Figure 2. Note that the configuration of both ends in the longitudinal direction (Ya side and Yb side) of the header tank 3 is the same, and the configuration of both ends in the short direction (Za side and Zb side) is the same. Therefore, the Ya side end and the Za side end will be used as examples in the following explanation.

[0029] Referring to Figures 2 and 3, the header tank 3 has a cylindrical body 30 composed of a first tank member 31 and a second tank member 32, and caps 33 that close the openings at both ends of the cylindrical body 30 in the longitudinal direction (header tank longitudinal direction). The first tank member 31 and the second tank member 32 are each half-cut. As shown in the upper part of Figure 3, in this example, the first tank member 31 is formed in a substantially U-shape when viewed from the side, and has a bottom surface 31B and two first sides 31S that extend in the longitudinal direction of the header tank and are opposite to each other. In this example, the second tank member 32 is formed in a substantially U-shape when viewed from the side, and has a bottom surface 32B and two second sides 32S that extend in the longitudinal direction of the header tank and are opposite to each other.

[0030] The first tank member 31 and the second tank member 32 are combined such that they close each other's roughly concave openings. In this configuration, the first tank member 31 and the second tank member 32 are positioned such that at least a portion of the first side surface 31S of the first tank member 31 overlaps with the inside of at least a portion of the second side surface 32S of the second tank member 32, thereby forming a cylindrical body 30. In other words, the cylindrical body 30 is composed of a single-layer region 301 consisting only of the first tank member 31 or the second tank member 32, and a double-layer region 302 formed by overlapping the first tank member 31 or the second tank member 32. In the example shown in Figure 3, the region where the second side surface 32S of the second tank member 32 exists is the double-layer region 302, and the remaining region is the single-layer region 301.

[0031] The cap 33 is made of a metal member (cap member) similar to the first tank member 31 and the second tank member 32, and is a cover lid having an edge portion 33T, as shown in the exploded view on the Yb side of Figure 2. That is, the edge portion 33T continuously covers the single-layer region 301 and the double-layer region 302 around the end opening of the cylindrical body 30, as shown in Figure 3. For this reason, the edge portion 33T is provided with a bent portion BN to correspond to the step difference caused by the difference in plate thickness between the single-layer region 301 and the double-layer region 302.

[0032] In this configuration, as shown in the enlarged view in the lower part of Figure 3, a boundary exists between the single-layer region 301 and the double-layer region 302 facing the outer bend R portion of the bent portion BN, and a roughly triangular prism-shaped gap G is created between them, extending along the bend line BL of the bent portion BN (in the depth direction shown). One end of the gap G (the end corresponding to the bottom of the triangular prism) is covered by the cap 33, but the other end communicates with the outside at the tip of the edge 33T of the cap 33. In particular, when the heat exchanger 1 is large, the thickness of the first tank member 31, the second tank member 32 and the cap 33 is thick, which increases the outer bend R, and as a result the gap G also increases.

[0033] Brazing material is applied to the inner surface of the cap 33 (outer bend R side, the right side in the lower diagram of Figure 3) and the outer surfaces of the first tank member 31 and the second tank member 32 (the left side in the lower diagram of Figure 3). Conventionally, it has been difficult to control the flow of molten brazing material, especially in the gap G portion, during the brazing process of assembly. For example, if the brazing material flows out to the outside due to uncontrolled flow in the gap G, there is a problem of brazing defects occurring in and around the gap G due to insufficient brazing material.

[0034] In this example, the outer surface of the second side 32S is partially thinned to create an inclined surface, thereby minimizing the outer bend radius of the bent portion BN as much as possible. However, a gap G is still unavoidable. In other words, even if the second side 32S were not thinned, a gap G would still occur, resulting in the same problem.

[0035] Therefore, in this embodiment, an inclined surface (or gradient, hereinafter the same) SL is provided on the outer surface of the cylindrical body 30 near the bend BN, sloping from the center in the longitudinal direction of the cylindrical body 30 toward the bend BN. The inclined surface SL is, for example, a part of a protrusion 35 provided on the outer surface of the cylindrical body 30 near the bend BN.

[0036] Figure 4 is an enlarged view of the Ya-side end of the header tank 3. Figure 4(A) is a partially exploded perspective view, and Figure 4(B) is a perspective view. Figure 4(C) is an exploded side view seen from the Ya side and a partially enlarged view thereof, with the second tank member 32 not shown. Figure 5 is an enlarged front view of the Ya-side end of the header tank 3.

[0037] The protruding portion 35 is provided, for example, near the bent portion BN and on the central side (Yb side in this example) in the longitudinal direction of the cylindrical body 30 (header tank longitudinal direction) than the bent portion BN (edge ​​portion 33T). The protruding portion 35 is made up of either the first tank member 31 or the second tank member 32, but it is desirable to provide it in the single-layer region 301 in order to avoid increasing the size of the header tank 3.

[0038] In the first example, the protrusion 35 (protrusion 35a) is made of the first tank member 31 and is provided adjacent to the bent portion BN. More specifically, in this example, as shown in Figures 4(B) and 5, the tip surface 33Ts of the edge portion 33T of the cap 33 and the upper end surface 32Su of the second side surface 32S that constitutes the outer surface of the two-layer region 302 rise vertically with respect to the first side surface 31S by the thickness of the respective members, forming a substantially L-shaped section.

[0039] The protruding portion 35a is provided so as to be close to the tip surface 33Ts and the upper end surface 32Su and to fit within the said section, and at least the region facing the tip surface 33Ts and the upper end surface 32Su is an inclined surface SL.

[0040] Referring to Figure 4(C), the inclined surface SL is a surface that is inclined with the outer surface of the first side surface 31S (cylindrical body 30) being the lower part and a position away from the lower part in the short direction (Z direction) of the header tank being the higher part. In this example, the protruding portion 35a is dome-shaped (approximately hemispherical) in which the first tank member 31 protrudes outward from the first side surface 31S in the short direction (Z direction) of the header tank, and the base portion is a curved surface that is inwardly convex and gently continues to the first side surface 31S.

[0041] In terms of positional relationship in the short direction (Z direction) of the header tank, the top of the protrusion 35a is located in a position that protrudes outward in the short direction of the cylindrical body 30 beyond the inner surface of the bent portion BN (the position of the bend line BL shown in Figure 4(C) and the lower part of Figure 3). In other words, in the short direction of the header tank, the protrusion 35a has a high point at the position that protrudes outward from the inner surface of the bent portion BN beyond the cylindrical body 30, and includes an inclined surface SL that extends from that position toward the lower part of the bent portion BN.

[0042] With this configuration, when the brazing material on the outer surface of the first tank member 31 melts during brazing, at least a portion of the brazing material at the protruding portion 35a is guided in the direction of the bent portion BN by the inclined surface SL. For example, in Figure 5, at least below the center of the protruding portion 35a, the brazing material flows through a narrow channel sandwiched between the base portion of the protruding portion 35a and the tip surface 33Ts of the cap 33 and / or the base portion of the protruding portion 35a and the upper end surface 32Su of the second tank member 32, or flows directly into the gap G, as indicated by the arrow.

[0043] As described above, according to this embodiment, the inclined surface SL of the protruding portion 35a controls the flow of the brazing material and guides it into the gap G. As a result, it is possible to suppress the arbitrary flow of the molten brazing material, and for example, it is possible to prevent a shortage of brazing material in the gap G, which would result in a poor brazing job.

[0044] Furthermore, the protrusion 35a may also be used as a guide when additional brazing material is to be placed (when brazing by placing the material on top). By brazing by placing the material on top of the protrusion 35a, at least a portion of the additional brazing material can be guided into the gap G by the inclined surface SL.

[0045] Furthermore, the inclined surface SL and the protruding portion 35 are also provided on the first side surface 31S on the Zb side of the header tank 3 on the Ya side, and on the opposing first side surface 31S on the Yb side of the header tank 3.

[0046] <Second example> Figures 6 and 7 are enlarged views of the Ya-side end of the header tank 3 in the second example. Figure 6(A) is a partially exploded perspective view, and Figure 5(B) is a partially exploded side view seen from the Ya side, and a partially enlarged view thereof. Figure 6 is a front view seen from the Za side. The header tank 3 in the second example differs from that of the first example in the configuration of the protruding portion 35, but is otherwise the same as that of the first example.

[0047] Referring to Figure 5, the projection 35 (projection 35b) in the second example is approximately cubic or approximately truncated square pyramidal in shape. The projection 35b is made of the first tank member 31 and is provided adjacent to the bent portion BN.

[0048] As shown in Figure 7, the protrusion 35b of the second example is also positioned close to the tip surface 33Ts of the cap 33 and the upper end surface 32Su of the second tank member 32, and is provided to fit within the roughly L-shaped section formed by them. At least the region facing the tip surface 33Ts and the upper end surface 32Su is an inclined surface SL. Furthermore, as shown in Figure 6(B), the base portion of the protrusion 35b has a curved surface that is inwardly convex and gently continues to the first side surface 31S.

[0049] The top of the protruding portion 35b is a flat surface, but in terms of its positional relationship in the short-side direction (Z direction) of the header tank, the top of the protruding portion 35b is positioned to protrude outward in the short-side direction of the cylindrical body 30 from the inner surface of the bent portion BN (the position of the bend line BL shown in Figure 6(B) and the lower part of Figure 3). In other words, in the short-side direction of the header tank, the protruding portion 35b includes an inclined surface SL that slopes in the direction of the bent portion BN, starting from a position that protrudes outward from the inner surface of the bent portion BN of the cylindrical body 30.

[0050] When the brazing material on the outer surface of the first tank member 31 melts during brazing, at least a portion of the brazing material at the protruding portion 35b is guided in the direction of the bent portion BN by the inclined surface SL. For example, in Figure 7, at least below the center of the protruding portion 35b, the brazing material flows through a narrow channel sandwiched between the base portion of the protruding portion 35b and the tip surface 33Ts of the cap 33 and / or the base portion of the protruding portion 35b and the upper end surface 32Su of the second tank member 32, or flows directly into the gap G, as indicated by the arrow.

[0051] Thus, in the second example as well, the inclined surface SL of the protruding portion 35b controls the flow of the brazing material and guides it into the gap G. As a result, it is possible to suppress the arbitrary flow of the molten brazing material, and for example, it is possible to prevent a shortage of brazing material in the gap G, which would result in a poor brazing job.

[0052] Furthermore, the protrusion 35b may also be used as a guide when additional brazing material is to be placed (when brazing by placing the material on top of the protrusion 35b). By brazing by placing the material on top of the protrusion 35b, the additional brazing material can also be guided into the gap G by the inclined surface SL. Compared to the first example, since the upper surface of the protrusion 35b is flat, it is easier to hold the brazing material when adding it.

[0053] As described above, the shape of the protrusion 35 in this embodiment is not limited to the above example, and any shape having an inclined surface SL that guides the brazing material into the bent portion BN (gap G) is acceptable. For example, the protrusion 35 shown in Figures 5 and 7 may be configured such that the inclined surface SL is only present in the area facing the tip surface 33Ts of the cap 33 and the upper end surface 32Su of the second tank member 32, respectively, and the upper half of the protrusion 35 in the height direction (X direction) in Figures 5 and 7 is not provided.

[0054] Furthermore, the above explanation illustrates the case where the inclined surface SL is part of the surface of the protruding portion 35, but it is not limited to this. For example, a groove may be provided on the surface of the protruding portion 35, extending from the top towards the bent portion BN (gap G), and the flow of the brazing material may be controlled by this groove. In this case, the bottom surface of the groove becomes the inclined surface SL. Also, the inclined surface SL may be a curved surface or a flat surface.

[0055] Furthermore, the inclined surface SL only needs to guide the brazing material into the bent portion BN (gap G). In other words, the inclined surface SL is not limited to a part of the protruding portion 35, but may also be formed by, for example, thinning a portion of the first side surface 31S of the first tank member 31 near the bent portion BN, or by making a portion of the first side surface 31S stepped.

[0056] Furthermore, the cylindrical body 30 may be joined such that the second side surface 32S abuts against the inside of the first side surface 31S, in which case the inclined surface SL (projection 35) may be formed on the second side surface 32S.

[0057] It should be noted that the heat exchanger 1 of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention. [Explanation of Symbols]

[0058] 1 heat exchanger 2 tubes 3, 4 Header Tanks 5 Side Plates 30 Cylindrical body 31 First Tank Component 31B Bottom 31S first side 32 Second Tank Components 32S second side 32B Bottom 32Su top surface 33 caps 33T edge 33Ts tip surface 35 Protrusion 301 One layer area 302 Two layer area BL bending wire BN bend section G Gap SL slope

Claims

1. A heat exchanger comprising a cylindrical body and a header tank having a cap that closes the opening at the end of the cylindrical body, The cylindrical body is formed by combining a first member and a second member, and includes a single-layer region consisting only of the first member or the second member, and a double-layer region in which the first member and the second member are stacked. The cap has a bent portion at its edge to continuously cover the single-layer region and the double-layer region around the opening. An inclined surface is provided on the outer surface of the cylindrical body near the bend, extending from the center in the longitudinal direction of the cylindrical body toward the bend. A heat exchanger characterized by the following features.

2. The inclined surface is provided in the single-layer region and is inclined toward the direction of the bend from a position that protrudes outward from the inner surface of the bend beyond the outer surface of the cylindrical body. The heat exchanger according to feature 1.

3. The inclined surface is part of a protrusion provided on the outer surface of the cylindrical body near the bent portion. The heat exchanger according to feature 1.

4. The aforementioned inclined surface is the brazing material placement area in the brazing process. The heat exchanger according to feature 1.

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