Heat exchanger and method for manufacturing the heat exchanger

Abstract

The heat exchanger (1) has a plurality of flat tubes (31), plates (32) mounted at the ends of the plurality of flat tubes (31), a medium cover (35) that forms a medium flow path by covering the openings (31a) of the plurality of flat tubes (31), and a reinforcing member (50) that reinforces the openings (31a). The reinforcing member (50) has at least a pair of legs (51) and a connecting portion (52) that connects the legs (51). The insertion amount of the legs (51) into the openings (31a) is larger than the sum of the gap between the connecting portion (52) and the inner surface of the medium cover (35) and the length from the openings (31a) to the position corresponding to the brazed portion between the flat tubes (31) and the plates (32). Alternatively, when a protruding portion (53) protruding in the direction opposite to the insertion direction of the legs (51) is provided on the connecting portion (52), it is larger than the sum of the gap between the protruding portion (53) and the inner surface of the medium cover (35) and the length from the openings (31a) to the position corresponding to the brazed portion.

Description

Technical Field

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

[0002] There is a heat exchanger configured to cool engine cooling water flowing through a plurality of flat tubes by external air sucked from outside the engine. In such a heat exchanger, particularly when the external air temperature is low, relatively high-temperature hot water flows sharply into the flat tubes of the heat exchanger with respect to the low-temperature external air flowing into the heat exchanger.

[0003] In a heat exchanger, the rigidity of the flat tube is lower than that of the plate into which the flat tube is inserted. Therefore, there is a tendency for thermal strain to accumulate in the flat tube with low rigidity near the brazed portion between the outer surface of the flat tube and the edge of the insertion hole of the flat tube formed in the plate. In response to this, a reinforcement structure for reinforcing the flat tube near the brazed portion has been proposed (see JP5706665B). Summary of the Invention

[0004] However, in the reinforcement structure described in JP5706665B, in the operation process of assembling the tank after inserting the reinforcement member into the opening of the flat tube, it is impossible to visually confirm the detachment of the brazed reinforcement member, etc. Therefore, it is necessary to consider preventing the reinforcement member from detaching from the opening. In addition, during the brazing joint after the assembly process, there is also a positional deviation of the reinforcement member caused by vibrations during the manufacturing process and thickness reduction due to the melting of the brazing filler metal. Therefore, it hinders the improvement of the operation efficiency of manufacturing the heat exchanger and the yield of the product.

[0005] An object of the present invention is to improve the operation efficiency and yield of manufacturing the heat exchanger.

[0006] According to an aspect of the present invention, there is provided a heat exchanger, which includes: a plurality of flat tubes that form a medium flow path; a plate having a plurality of insertion holes formed in shapes identical to the cross-sectional shapes of the plurality of flat tubes respectively, with one flat tube of the plurality of flat tubes inserted into each insertion hole, and the plate is installed at the ends of the plurality of flat tubes; a medium cover that forms a medium flow path by covering the openings of the plurality of flat tubes inserted into the insertion holes; and a reinforcement member that reinforces the openings. The plurality of flat tubes, the plate, the medium cover, and the reinforcement member are connected using solder. The reinforcement member has at least a pair of legs and a connecting portion that connects the legs. The reinforcement member is inserted into the opening in such a manner that the legs are located on the inner surfaces of the opening that are opposed in the long-axis direction, and a part of the legs is in contact with the inner surfaces of the opening that are opposed in the short-axis direction. The insertion amount of the legs into the opening is greater than the sum of the gap between the connecting portion and the inner surface of the medium cover and the length from the opening to the position corresponding to the brazed portion of the flat tube and the plate. Alternatively, when a protruding portion that protrudes in the direction opposite to the insertion direction of the legs is provided on the connecting portion, it is greater than the sum of the gap between the protruding portion and the inner surface of the medium cover and the length from the opening to the position corresponding to the brazed portion.

[0007] According to the above aspect, in a state where the legs of the reinforcement member are inserted into the opening, the gap between the tip of the protruding portion and the inner surface of the cover is smaller than the insertion amount of the legs into the opening. Therefore, even if the reinforcement member moves in the direction opposite to the insertion direction from the opening, the legs will not be pulled out of the opening. As a result, the detachment of the reinforcement member from the opening is prevented. Therefore, in a manufacturing process where it is impossible to visually confirm the detachment of the reinforcement member after brazing, etc., the operation reliability can be improved without special consideration, and the operation efficiency and yield of manufacturing the heat exchanger can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a plan view showing a heat exchanger according to an embodiment of the present invention.

[0009] Figure 2 It is for Figure 1 a perspective view showing a partially disassembled state of the part shown by a double-dashed line.

[0010] Figure 3 It is a perspective view for explaining a reinforcement member applied to a heat exchanger.

[0011] Figure 4 It is a view for explaining a state where a reinforcement member applied to a heat exchanger has been assembled, and is a cross-sectional view showing a part cut along the extending direction of the flat tube shown in Figure 2 the figure. Detailed Embodiment

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] Figure 1 FIG. is a plan view showing the heat exchanger 1 of the present embodiment. Figure 2 For Figure 1 is a perspective view showing a partial decomposition of the part shown by a double-dashed line. In addition, in order to simplify the description, a part of the heat exchanger 1 is omitted and illustrated.

[0014] The heat exchanger 1 is used as a water-cooled charge air cooler that cools the intake air (fluid) supercharged and supplied to an engine (not shown) using a coolant (medium).

[0015] The heat exchanger 1 has a pair of intake hoods 11 and 12 (flow path components) that guide the intake air and a core part 30 through which the coolant circulates. The core part 30 is interposed between the pair of intake hoods 11 and 12. The intake air flowing through the core part 30 via the intake hoods 11 and 12 releases heat to the coolant flowing inside the core part 30 and is cooled.

[0016] The resin intake hoods 11 and 12 have dome-shaped open end parts 13 and 14 that open toward the core part 30 and cylindrical tube parts 15 and 16 that open toward the opposite side of the core part 30. A duct (not shown) is connected to the tube parts 15 and 16. The intake air is configured to flow into the inside of the core part 30 via one intake hood 11 as shown by the reversed white arrow, flow around the flat tubes 31 (refer to Figure 2 ) arranged inside the core part 30, and then flow out from the other intake hood 12.

[0017] The metal core part 30 has: a plurality of flat tubes 31 (refer to Figure 2 ) having a flat cross-section and forming a medium flow path, plates 32 and 33 for mounting the plurality of flat tubes 31, and a plurality of core plates 34 that form a housing part for housing the plurality of flat tubes 31 between the plates 32 and 33. In addition, the core part 30 has upper side medium covers 35 and 36 that cover the plate 32 for mounting the plurality of flat tubes 31 and lower side medium covers 37 that cover the plate 33. Pipes 38 and 39 are respectively connected to the upper side medium covers 35 and 36.

[0018] As Figure 2 shown, the plate 32 has a shape formed to be the same as the cross-sectional shape of the plurality of flat tubes, and a plurality of insertion holes 32h into which each of the plurality of flat tubes is inserted, and is mounted at the ends of the plurality of flat tubes 31. In Figure 1 , the plate 33 arranged on the lower side of the core part 30 is also formed in the same manner as the plate 32.

[0019] The frame-shaped plate 41 is provided on one side of the box body formed by the plates 32, 33 and the core plate 34. The opening end 13 of the intake hood body 11 is mounted on the plate 41. Similarly, the frame-shaped plate 42 is joined to the other side of the box body. The opening end 14 of the intake hood body 12 is mounted on the plate 42.

[0020] The upper side medium hood bodies 35, 36 are joined in such a manner as to cover the opening portions 31a of the plurality of flat tubes 31 inserted into the insertion holes 32h of the plate 32. In addition, the lower side medium hood body 37 is joined in such a manner as to cover the opening portions 31a of the plurality of flat tubes 31 inserted into the insertion holes (not shown) of the plate 33. Thus, a medium flow path is formed which starts from the pipe 38, turns back at the lower side medium hood body 37 via the flat tubes 31, and discharges from the pipe 39 via the flat tubes 31.

[0021] During engine operation, as shown by the black arrow, the coolant sent from a pump (not shown) via a pipeline flows into the interior of the flat tube 31 through one of the pipes 38, and flows out from the other pipe 39 after flowing through the medium flow path inside the flat tube 31.

[0022] As Figure 2 shown, the opening portion 31a of the flat tube 31 inserted into the insertion hole 32h of the plate 32 has a reinforcing member 50 for reinforcing the opening portion 31a.

[0023] Next, the reinforcing member 50 will be described. Figure 3 FIG. is a perspective view for explaining the reinforcing member 50 applied to the heat exchanger 1. Figure 4 FIG. is a view for explaining the state in which the reinforcing member 50 has been assembled to the opening portion 31a of the flat tube 31, and is a cross-sectional view taken by cutting away a part along the Figure 2 extension direction of the flat tube 31 shown.

[0024] The reinforcing member 50 has at least a pair of legs 51 and a connecting portion 52 that connects the legs 51. The legs 51 are inserted into the opening portion 31a of the flat tube 31. In addition, the connecting portion 52 connects the legs 51 and constitutes the main body portion of the reinforcing member 50.

[0025] In addition, the reinforcing member 50 has a protruding portion 53 formed on a part of the connecting portion 52 so as to protrude in a direction opposite to the direction in which the legs 51 are inserted into the opening portion 31a ( Figure 3 the arrow shown).

[0026] The reinforcing member 50 can be formed by subjecting a flat plate to blanking (cutting) and bending processes. As an example, the flat plate material for forming the reinforcing member 50 is cut by blanking into a substantially H shape in which the portions constituting the legs 51 extend from both sides of the connecting portion 52. Then, the legs 51 and the protruding portions 53 can be formed by bending. In addition, blanking and bending can also be formed in one stamping process.

[0027] In the reinforcing member 50 obtained by such processing, a bent portion 54 connecting the connecting portion 52 and the legs 51 is formed. The bent portion 54 connects the connecting portion 52 and the legs 51 and can be processed to have a specified bending degree R. In addition, the reinforcing member 50 has a flat portion 55 connected to the bent portion 54.

[0028] In the present embodiment, as Figure 2 shown, a pair of legs 51 are formed such that the legs 51 are located on the inner surfaces facing each other in the major axis direction (La) of the opening 31a. In addition, a part of the legs 51 is inserted into the opening 31a in such a manner as to contact the facing inner surface in the minor axis direction (Lb) of the opening 31a.

[0029] In the present embodiment, another pair of legs 51 are formed such that the legs 51 are located on the inner surfaces facing each other in the major axis direction of the opening 31a of the other flat tubes 31 arranged along the minor axis direction (Lb). That is, in the present embodiment, the reinforcing member 50 has four legs 51.

[0030] In the present embodiment, the flat tubes 31, the plates 32, 33, the core plate 34, the plates 41, 42, the upper side medium covers 35, 36, the lower side medium covers 37, fins (not shown), the pipes 38, 39, and the reinforcing member 50 are connected using solder.

[0031] In the present embodiment, the reinforcing member 50 is installed across adjacent flat tubes 31. The protruding portions 53 are located between the openings 31a of the adjacent flat tubes 31.

[0032] In addition, in the present embodiment, the reinforcing member 50 is provided at the opening 31a located on the fluid inflow side facing the upper side medium cover 35. In Figure 2 in order to illustrate the flat tube 31 and the insertion hole 32h, there is a place where a part of the reinforcing member 50 is not depicted, but the reinforcing member 50 can also be arranged at the left opening 31a in Figure 2 in.

[0033] In addition, a protrusion 56 protruding toward the end face 31e of the opening 31a of the flat tube 31 is formed on the flat portion 55 of the leg 51 in a direction intersecting the direction of insertion into the opening 31a.

[0034] As Figure 4 shown, the foot portion 51 is inserted along the inner surface of the flat tube 31 to a position corresponding to the joint portion A (shown within the dashed circle in Figure 4 ), and the joint portion A is a brazed portion between the outer side 31c of the flat tube 31 and the edge portion 32e of the insertion hole 32h.

[0035] In the reinforcing member 50, the protruding portion 53 is formed between the foot portions 51 in the major axis direction (La) of the opening portion 31a.

[0036] The reinforcing member 50 is inserted into the opening portion 31a such that the gap between the connecting portion 52 and the inner surface of the upper side medium cover 35 is smaller than the insertion amount of the foot portion 51 into the opening portion 31a. The gap between the connecting portion 52 and the inner surface of the upper side medium cover 35 refers to the distance between the connecting portion 52 and the inner surface of the upper side medium cover 35 in the insertion direction of the reinforcing member 50 into the opening portion 31a.

[0037] In the present embodiment, it is inserted into the opening portion 31a such that the gap d between the tip 53e of the protruding portion 53 and the inner surface of the upper side medium cover 35 is smaller than the insertion amount D of the foot portion 51 into the opening portion 31a. That is, the relationship d < D is formed.

[0038] Furthermore, it is formed such that the gap d between the tip 53e of the protruding portion 53 and the inner surface of the upper side medium cover 35 is smaller than the gap d0 between the bent portion 54 and the inner surface of the upper side medium cover 35.

[0039] Furthermore, in the present embodiment, in order to ensure that the foot portion 51 is inserted to a position corresponding to the joint portion A between the outer side 31c of the flat tube 31 and the edge portion 32e of the insertion hole 32h, the insertion amount D of the foot portion 51 into the opening portion 31a is larger than the sum of the gap d0 between the connecting portion 52 and the inner surface of the upper side medium cover 35 and the length D0 from the opening portion 31a to the lower end of the joint portion A which is the brazed portion between the flat tube 31 and the plate 32. Here, the lower end refers to the end of the joint portion A located on the central side in the extending direction of the flat tube 31. That is, the relationship d0 + D0 < D is formed. Furthermore, in the case where the protruding portion 53 is formed, the relationship d + D0 < D is formed.

[0040] The protruding portion 53 is configured to deform along the insertion direction when in contact with the inner surface of the upper side medium cover 35.

[0041] In the present embodiment, after assembling the flat tube 31, plates 32, 33, core plate 34, plates 41, 42, upper side medium covers 35, 36, lower side medium cover 37, fins (not shown), pipes 38, 39, and reinforcing member 50, they are heated and brazed to manufacture the heat exchanger 1.

[0042] Any one of the inner side of the flat tube 31, the inner sides of the upper side medium covers 35 and 36, and the reinforcing member 50 may also be formed of a material that does not contain a solder layer.

[0043] In the heat exchanger 1 of the present embodiment, in the above structure, the reinforcing member 50 is formed of a brazing plate with solder layers coated on both sides. In addition, a solder layer is coated on the outer side of the flat tube 31, but there is no solder layer on the inner side. Further, no solder layer is coated on the upper side medium covers 35 and 36. In addition, solder layers are coated on both sides of the plate 32. Therefore, after assembling all the components, the entire heat exchanger 1 is placed in a furnace set to a specified temperature, whereby all the components can be integrally brazed and fixed.

[0044] <Function and Effect>

[0045] In the heat exchanger 1 of the present embodiment, the reinforcing member 50 for reinforcing the opening 31a of the flat tube 31 is formed such that, in a state where its leg portion 51 is inserted into the opening 31a, the gap d between the tip 53e of the protruding portion 53 and the inner surface of the upper side medium cover 35 is smaller than the insertion amount D of the leg portion 51 into the opening 31a (that is, d < D).

[0046] Thereby, even if the leg portion 51 of the reinforcing member 50 moves in a direction opposite to the insertion direction from the opening 31a of the flat tube 31, the tip 53e of the protruding portion 53 will abut against the inner side of the upper side medium cover 35 before the leg portion 51 is pulled out from the opening 31a. Therefore, the reinforcing member 50 is prevented from falling off from the opening 31a of the flat tube 31. Therefore, no special consideration is required in the manufacturing process of the heat exchanger 1. Therefore, the working efficiency and the yield rate of manufacturing the heat exchanger 1 can be improved.

[0047] In the heat exchanger 1 having such a structure, it can be preferably applied to a fixing method such as brazing that is difficult to disassemble and reassemble after assembling all the structures.

[0048] One pair of the four leg portions 51 of the reinforcing member 50 is located on the inner surfaces facing each other in the major axis direction (La) of the opening 31a, and the other pair is located on the inner surfaces facing each other in the major axis direction of the openings 31a of the adjacent flat tubes 31 arranged along the minor axis direction (Lb). That is, in the present embodiment, the reinforcing member 50 is installed across the adjacent flat tubes 31, and the protruding portion 53 of the reinforcing member 50 is located between the openings 31a of the adjacent flat tubes 31.

[0049] The reinforcing member 50 is configured in such a structure, whereby the flow of the coolant (medium) flowing into the opening 31a of the flat tube 31 is not obstructed.

[0050] In addition, a protrusion 56 is formed on the flat portion 55 of the leg portion 51. It is conceivable that, when the end face 31e of the opening portion 31a reaches the bent portion 54 of the reinforcing member 50, unnecessary stress that causes the adjacent flat tubes 31 to expand in a direction away from each other acts on the leg portion of the reinforcing member 50.

[0051] In contrast, in the present embodiment, the flat portion 55 has the protrusion 56. Thus, when the leg portion 51 is inserted into the opening portion 31a, the leg portion 51 is restricted by the protrusion 56. As a result, the leg portion 51 will not be excessively inserted into the flat tube 31. Therefore, while the flat tube 31 is reinforced by the reinforcing member 50, deformation of the flat tube 31 caused by the reinforcing member 50 can be prevented.

[0052] In addition, in the reinforcing member 50, the protruding portion 53 is formed at the central portion of the connecting portion 52 that connects the leg portions 51 in the major axis direction (La) of the opening portion 31a. Thus, it is easy to obtain the effect of restricting the position of the reinforcing member 50 when the leg portion 51 of the reinforcing member 50 moves in a direction opposite to the insertion direction from the opening portion 31a of the flat tube 31.

[0053] In addition, even if each reinforcing member 50 has a tolerance in the molding size, when the upper medium cover 35 is assembled, the protruding portion 53 abuts against the inner surface of the upper medium cover 35. Therefore, the effect of restriction can also be easily obtained so that the leg portion 51 of the reinforcing member 50 will not move in a direction opposite to the insertion direction from the opening portion 31a of the flat tube 31.

[0054] In addition, the protruding portion 53 abuts against the inside of the upper medium cover 35 and deforms in the insertion direction. Therefore, in a state where the upper medium cover 35 is assembled to the plate 32, it does not prevent the upper medium cover 35 from closely engaging with the plate 32.

[0055] In addition, the connecting portion 52 formed with the protruding portion 53 is configured to deform toward the inside of the flat tube 31 when the protruding portion 53 abuts against the inside of the upper medium cover 35 and deforms in the insertion direction. Therefore, when the protruding portion 53 abuts against the inside of the upper medium cover 35, the leg portion 51 can absorb the stress acting in a direction that expands the end face 31e of the opening portion 31a of the flat tube 31 outward. In this way, the reinforcing member 50 can reinforce the flat tube 31 while preventing deformation of the flat tube 31.

[0056] In addition, in the present embodiment, the reinforcing member 50 is disposed at the opening portion 31a on the side closest to the intake hood 11, that is, the reinforcing member 50 is disposed at a position where the flat tube 31 is likely to be thermally strained. Thus, the reinforcing effect on the accumulation of thermal strain of the flat tube 31 can be improved.

[0057] In addition, in the heat exchanger 1 of the present embodiment, the reinforcing member 50 and the plate 32 are formed of a filler metal plate coated with a filler metal layer on both sides, the flat tube 31 is formed of a filler metal plate coated with a filler metal layer only on one side (the outer side of the tube), and the filler metal layer is not coated on the inner sides of the upper medium covers 35 and 36.

[0058] Thereby, the flat tube 31 and the plate 32 are joined by the filler metal on the outer surface of the flat tube 31 and the filler metal of the plate 32, the plate 32 and the upper medium cover 35 are joined by the filler metal of the plate 32, and the flat tube 31 and the reinforcing member 50 are joined by the filler metal of the reinforcing member. For example, even when the position of the reinforcing member 50 is slightly deviated and comes into contact with the inner side of the upper medium cover 35 or the like, since the filler metal layer is not provided on the inner side of the upper medium cover 35, the remaining filler metal does not flow into the inside of the flat tube 31. In addition, it is possible to prevent a decrease in the durability of the heat exchanger 1 due to a local thickness reduction or the like that may be caused by an excessive amount of filler metal. As a comparative example, a filler metal for joining with the plate 32 is provided on the inner surface of the upper medium cover 35. When the position of the reinforcing member 50 is deviated and comes into contact with the upper medium cover, the filler metal of the reinforcing member acts as a bridge and causes the filler metal to flow into the tube, resulting in an excessive amount of filler metal.

[0059] [Other Embodiments]

[0060] The embodiments of the present invention have been described above. However, the above embodiments only show a part of the application examples of the present invention, and the technical scope of the present invention is not limited to the specific structures of the above embodiments.

[0061] The shape of the protruding portion 53 is not limited as long as the gap d between the tip 53e of the protruding portion 53 and the inner surface of the upper medium cover 35 is smaller than the insertion amount D of the leg portion 51 into the opening 31a in a state where the leg portion 51 is inserted into the opening 31a. The tip 53e may be formed as a flat surface. In addition, the protruding portion 53 is not limited to one. For example, the protruding portion 53 may have two peaks.

[0062] In addition, it can be applied to other heat exchangers, not limited to water-cooled charge air coolers.

[0063] This application claims priority based on Japanese Patent Application No. 2019-199113 filed with the Japan Patent Office on October 31, 2019, and the entire contents of this application are incorporated herein by reference.

Claims

1. A heat exchanger, comprising: a plurality of flat tubes that form a medium flow path; plates each having a plurality of insertion holes formed in a shape identical to the cross-sectional shape of the plurality of flat tubes for inserting one of the plurality of flat tubes respectively, and being installed at ends of the plurality of flat tubes; a medium cover that forms the medium flow path by covering openings of the plurality of flat tubes inserted into the insertion holes; and a reinforcement member for reinforcing the openings, connecting the plurality of flat tubes, the plates, the medium cover, and the reinforcement member using solder, the reinforcement member having at least a pair of legs and a connecting portion connecting the legs, the reinforcement member being inserted into the openings such that the legs are located on inner surfaces of the openings opposing each other in the major axis direction and a part of the legs is in contact with inner surfaces of the openings opposing each other in the minor axis direction, an insertion amount of the legs into the openings being larger than a sum of a gap between the connecting portion and an inner surface of the medium cover and a length from the openings to a position corresponding to a soldered portion between the flat tubes and the plates, when a protruding portion protruding in a direction opposite to an insertion direction of the legs is provided on the connecting portion, the insertion amount of the legs into the openings being larger than a sum of a gap between the protruding portion and an inner surface of the medium cover and a length from the openings to a position corresponding to the soldered portion.

2. The heat exchanger according to claim 1, wherein the reinforcement member has a bent portion connecting the connecting portion and the legs, a gap between the protruding portion and an inner surface of the medium cover being smaller than a gap between the bent portion and an inner surface of the medium cover.

3. A method for manufacturing a heat exchanger for manufacturing the heat exchanger according to claim 1 or 2, wherein any one of an inner side of the flat tubes, an inner side of the medium cover, and the reinforcement member is formed of a material not containing a solder layer, assembling the flat tubes, the plates, the medium cover, and the reinforcement member, and performing heated soldering after the assembling.

4. The method for manufacturing a heat exchanger according to claim 3, wherein the inner sides of the flat tubes and the inner side of the medium cover are formed of a material not containing a solder layer, [[ID=B19]]the reinforcement member and the plates are formed of a material having solder layers formed on both sides. It should be noted that in the original text, there might be a typo in [[ID=B19]] where it should probably be in the English translation. I've translated it as [[ID=B19]] as per your request to preserve the original tag but it might need to be corrected in the source text for a more accurate translation.

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