Heat exchanger and manufacturing method of the same

Abstract

To use laser welding to secure strength of a manufactured heat exchanger.SOLUTION: A heat exchanger 100 includes a first member 10 and a second member 20 joined by laser welding and a fluid passage is formed between the first member 10 and the second member 20. The second member 20 has ribs 23 which are joined to the first member 10 by the laser welding and partition the passage. A rib welding bead 28 for joining the rib 23 to the first member 10 has an arc part 282 formed in an arc shape at an end; its joint depth shallows toward a tip of the arc part 282 which is a starting point or an end point of the laser welding; and a preceding bead and a following bead do not overlap in a track of the rib welding bead 28 or a joint depth in the tip of the arc part 282 is set to a depth at which the first member 10 and the second member 20 are not joined.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a temperature adjustment device for a storage battery including a heating part in which an upper surface part and a lower surface part are joined by brazing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When joining members by brazing like the above heating part (heat exchanger), in a mass production process, it is common to provide a brazing heating furnace. However, for example, when the size of the heating part is large, the heating furnace also has to be enlarged according to the size, making it difficult to improve production efficiency.

[0005] Therefore, instead of brazing, it is conceivable to join members by laser welding. However, in this case, stress concentration is likely to occur around the weld bead due to the internal pressure of the heating part.

[0006] The present invention has been made in view of the above problems, and an object thereof is to ensure the strength of a heat exchanger manufactured using laser welding.

Means for Solving the Problems

[0007] According to an aspect of the present invention, there is provided a heat exchanger including a first member and a second member joined by laser welding, and a fluid flow path is formed between the first member and the second member. The second member has ribs joined to the first member by the laser welding to partition the flow path. The rib weld bead joining the rib to the first member has an arcuate portion at an end, and the joining depth becomes shallower toward the tip of the arcuate portion, which is the start point or the end point of the laser welding. A heat exchanger is provided in which the leading bead and the trailing bead do not overlap in the track of the rib weld bead or the joining depth at the tip of the arcuate portion is a depth at which the first member and the second member are not joined.

Effects of the Invention

[0008] According to the above aspect, since the end of the rib weld bead where stress concentration is likely to occur due to the internal pressure of the heat exchanger is formed into an arcuate arcuate portion, stress concentration at the end of the rib weld bead can be suppressed. Further, since the joining depth is made shallower at the tip of the arcuate portion, that is, at the start / end point of the laser welding, the heat input can be made appropriate and the welding quality can be improved. Furthermore, when the leading bead and the trailing bead do not overlap in the track of the rib weld bead, it is possible to prevent the trailing bead from affecting the joining strength of the leading bead. The same applies when the joining depth at the tip of the arcuate portion is set to a depth at which the first member and the second member are not joined. Even if the tip of the arcuate portion overlaps with the leading bead, it is possible to prevent the joining strength of the leading bead from being affected. Therefore, according to the above aspect, the strength of the heat exchanger manufactured using laser welding can be ensured.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the heat exchanger 100 according to the embodiment of the present invention will be described with reference to the accompanying drawings. In each figure, the same reference numerals are given to equivalent configurations.

[0011] Figure 1 is a side view showing the state where the heat exchanger 100 is mounted on the vehicle 200. Figure 2 is a top view showing the state where the heat exchanger 100 is mounted on the vehicle 200.

[0012] As shown in Figures 1 and 2, the heat exchanger 100 is attached to the vehicle 200 as an external device by a plurality of bolts 110.

[0013] A battery 120 is stacked on the heat exchanger 100. The battery 120 is held in a stacked state on the heat exchanger 100 by attaching a mounting member 130 attached from above the battery 120 to the vehicle 200 by bolts 110. Note that the heat exchanger 100 may be stacked on the battery 120.

[0014] The heat exchanger 100 is connected to a fluid supply pipe 140 for supplying a heat exchange fluid to the heat exchanger 100 and a fluid discharge pipe 150 for discharging the fluid from the heat exchanger 100. The heat exchange fluid is, for example, water.

[0015] By supplying a fluid at a temperature higher than that of the battery 120 to the heat exchanger 100, the battery 120 stacked on the heat exchanger 100 can be heated. Also, by supplying a fluid at a temperature lower than that of the battery 120 to the heat exchanger 100, the battery 120 stacked on the heat exchanger 100 can be cooled.

[0016] Subsequently, the heat exchanger 100 will be described.

[0017] FIG. 3 is a top view showing an example of the heat exchanger 100. FIG. 4 is a bottom view showing an example of the heat exchanger 100. FIG. 5 is a cross-sectional view taken along line V-V of FIG. 3. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 3.

[0018] As shown in FIGS. 3 and 4, the heat exchanger 100 includes a first member 10 and a second member 20. The materials of the first member 10 and the second member 20 are, for example, aluminum alloys.

[0019] The first member 10 and the second member 20 are joined by laser welding. In FIG. 3, the back bead of the laser welding is shown by a dotted line. In FIG. 4, the front bead of the laser welding is shown by a thick solid line. That is, in the present embodiment, the laser welding is performed from the second member 20 side. However, the laser welding may be performed from the first member 10 side.

[0020] The first member 10 is in a flat plate shape and has a fluid supply port 11 formed at one end side and a fluid discharge port 12 formed at the other end side. The fluid supply pipe 140 is connected to the fluid supply port 11. The fluid discharge pipe 150 is connected to the fluid discharge port 12.

[0021] The second member 20 includes a flange 21 that abuts against the first member 10, a recess 22 that forms a fluid flow path 27 between the second member 20 and the first member 10, a plurality of ribs 23 that are formed in the recess 22 and abut against the first member 10, and a plurality of protrusions 24 that extend outward from the flange 21 toward the outside of the heat exchanger 100. A hole 25 is formed in the protrusion 24. The protrusion 24 constitutes an attachment portion for attaching the heat exchanger 100 to the vehicle 200 with bolts 110.

[0022] The flange 21 is joined to the first member 10 by laser welding. The shape of the flange 21 is formed along the outer shape of the first member 10. Therefore, when the flange 21 and the first member 10 are joined by laser welding, an outer peripheral welding bead 26 that joins the outer peripheral portion of the heat exchanger 100 is formed so as to surround the fluid supply port 11 and the fluid discharge port 12. Thereby, a fluid flow path 27 is formed between the first member 10 and the second member 20.

[0023] As shown in FIG. 4, the two end portions 261 of the outer peripheral welding bead 26 are respectively located at the protrusions 24 (attachment portions). That is, the two end portions 261 of the outer peripheral welding bead 26 are located at positions away from the flow path 27. Therefore, stress concentration on the two end portions 261 of the outer peripheral welding bead 26 due to the internal pressure of the heat exchanger 100 can be suppressed.

[0024] Furthermore, in the present embodiment, the positions of the start point / end point of the outer peripheral welding bead 26 are set outside the heat exchanger 100, that is, at positions away from the flow path 27, compared to the center of the hole 25 formed in the protrusion 24. Thereby, stress concentration on the start point / end point of the outer peripheral welding bead 26 due to the internal pressure of the heat exchanger 100 can be suppressed.

[0025] As shown in FIGS. 4 and 5, each of the plurality of ribs 23 has a flat portion 231 that abuts against the first member 10 and a wall portion 232 that rises from the flat portion 231.

[0026] Each of the plurality of ribs 23 has a flat portion 231 joined to the first member 10 by laser welding. By partitioning the flow path 27 with the plurality of ribs 23, the fluid flowing through the flow path 27 is rectified.

[0027] As shown in FIG. 4, a rib weld bead 28 formed on the rib 23 by laser welding has a straight portion 281 along the longitudinal direction of the rib 23 and two arc portions 282 respectively formed in an arc shape at both ends of the straight portion 281.

[0028] As shown in FIGS. 4 and 5, the straight portion 281 is formed at the center in the width direction of the rib 23.

[0029] Therefore, the internal pressure of the heat exchanger 100 acts equally on both sides of the straight portion 281 from both sides of the rib 23. Thereby, the stress generated around the straight portion 281 can be evenly dispersed on both sides of the straight portion 281. That is, by forming the straight portion 281 at the center in the width direction of the rib 23, stress concentration on the straight portion 281 can be suppressed.

[0030] As shown in FIG. 4, the arc portion 282 is formed along the arc shape at the end of the rib 23. Specifically, the arc portion 282 of the present embodiment is formed on the circumference.

[0031] In this way, by forming the end of the rib weld bead 28 where stress concentration is likely to occur due to the internal pressure of the heat exchanger 100 into an arc-shaped arc portion 282, stress concentration at the end of the rib weld bead 28 can be suppressed.

[0032] Also, as shown in FIG. 6, the arc portion 282 is formed on the flat portion 231 along the R stop of the curved surface portion connecting the flat portion 231 and the wall portion 232 in the rib 23.

[0033] Thereby, the pressure receiving area of the flat portion 231 around the arc portion 282 can be reduced, so the stress generated around the arc portion 282 can be reduced.

[0034] In addition, at the tip of the arc portion 282, the rib weld bead 28 reduces the joint depth by means of an upslope / downslope.

[0035] By thus reducing the joint depth at the tip of the arc portion 282, that is, at the start / end point of laser welding, the heat input amount can be made appropriate and the welding quality can be improved.

[0036] FIG. 7 is a diagram for explaining the joint depth of the rib weld bead 28. In FIG. 7, the joint depths at points A to E shown in FIG. 4 are shown.

[0037] As shown in FIG. 7, in the section of the rib weld bead 28 from point A to point D, the joint depth is a predetermined value exceeding the plate thickness of the second member 20. Then, from point D to point E, the joint depth becomes shallower. Point E is the tip of the rib weld bead 28. Note that point E may be the start point or the end point of the rib weld bead 28.

[0038] As shown in FIG. 4, point D is a position where the circle drawn by the arc portion 282 exceeds a semi-circle, and a position where the tangent line of the arc portion 282 is parallel to the longitudinal direction of the rib 23. That is, point D is a point where the direction of the rib weld bead 28 becomes opposite to the direction in which the rib 23 extends toward the end.

[0039] By thus maintaining the joint depth without reducing it until the arc portion 282 forms at least a semi-circle and the tangent line of the arc portion 282 becomes parallel to the longitudinal direction of the rib 23 toward the tip side beyond the semi-circle, the pressure resistance at the end of the rib 23 where stress concentration is likely to occur can be improved.

[0040] In addition, in the present embodiment, as shown in FIG. 4, point E and point B are at the same position. That is, in the track of the rib weld bead 28, the tip (point E) of the rib weld bead 28, which is the subsequent bead, overlaps the intermediate portion (point B) of the rib weld bead 28, which is the preceding bead. In other words, the preceding bead and the subsequent bead overlap in the track of the rib weld bead 28.

[0041] On the other hand, as shown in FIG. 6, the joining depth of the rib weld bead 28 becomes shallower between point D and point E to a depth at which the first member 10 and the second member 20 are not joined.

[0042] According to this, even if the tip of the arc portion 282 overlaps the preceding bead as in the present embodiment, it is possible to prevent the joining strength by the preceding bead from being affected.

[0043] Subsequently, the rib weld bead 28 according to the first modification will be described with reference to FIG. 8. FIG. 8 is a diagram showing the rib weld bead 28 according to the first modification.

[0044] As shown in FIG. 8, the rib weld bead 28 of the first modification is different from the rib weld bead 28 shown in FIG. 4 in that it has an arcuate connecting portion 283 that connects the straight portion 281 and the arc portion 282.

[0045] In this way, by forming the connecting portion 283 that connects the straight portion 281 and the arc portion 282 in an arc shape, it is possible to suppress a local increase in the input of the laser at the connecting portion 283. Therefore, the welding quality can be improved.

[0046] Also, in the rib weld bead 28 of the first modification, point B and point E are separated. That is, the preceding bead and the succeeding bead do not overlap in the trajectory of the rib weld bead 28.

[0047] Thereby, it is possible to prevent the succeeding bead from affecting the joining strength by the preceding bead.

[0048] Subsequently, the rib weld bead 28 according to the second modification will be described with reference to FIG. 9. FIG. 9 is a diagram showing the rib weld bead 28 according to the second modification.

[0049] As shown in FIG. 9, the rib weld bead 28 of the second modification is different from the rib weld bead 28 shown in FIG. 4 in that its tip (point E') is separated from point B.

[0050] That is, in the rib weld bead 28 of the second modification, the leading bead and the trailing bead do not overlap in its trajectory.

[0051] This can prevent the trailing bead from affecting the joint strength by the leading bead.

[0052] FIG. 10 is a diagram for explaining the joint depth of the rib weld bead 28 according to the second modification.

[0053] As can be seen from FIGS. 9 and 10, in the rib weld bead 28 according to the second modification, the arc portion 282 forms at least a semi-circle, and the joint depth is not decreased until the tangent line of the arc portion 282 reaches a position (point D) where the tangent line of the arc portion 282 is parallel to the longitudinal direction of the rib 23 toward the tip side beyond the semi-circle.

[0054] This can improve the pressure resistance at the end of the rib 23 where stress concentration is likely to occur.

[0055] Subsequently, the rib weld bead 28 according to the third modification will be described with reference to FIG. 11. FIG. 11 is a diagram showing the rib weld bead 28 according to the third modification.

[0056] As shown in FIG. 11, the rib weld bead 28 of the third modification is different from the rib weld bead 28 shown in FIG. 4 in that the straight portion 281 is formed at a position deviated from the center of the rib 23 in the width direction of the rib 23. However, the other configurations of the rib weld bead 28 of the third modification are equivalent to those of the rib weld bead 28 shown in FIG. 4.

[0057] Specifically, the rib weld bead 28 of the third modification has an arc portion 282 formed in an arc shape at its end, and the leading bead and the trailing bead do not overlap in its trajectory.

[0058] Also, the joint depth becomes shallower toward the tip of the arc portion 282 which is the start point or the end point of the laser welding (not shown).

[0059] Therefore, according to the third modification example, since the end portion of the rib weld bead 28 where stress concentration is likely to occur due to the internal pressure of the heat exchanger 100 is formed into an arc-shaped arc portion 282, stress concentration at the end portion of the rib weld bead 28 can be suppressed. Further, since the joining depth is made shallow at the tip of the arc portion 282, that is, at the start / end point of laser welding, the heat input amount can be made appropriate and the welding quality can be improved. Furthermore, since the leading bead and the trailing bead do not overlap in the track of the rib weld bead 28, it is possible to prevent the trailing bead from affecting the joining strength of the leading bead.

[0060] Also, in the rib weld bead 28 of the third modification example, the arc portion 282 forms at least a semi-circle, and the joining depth is not made shallow until the tangent line of the arc portion 282 becomes parallel to the longitudinal direction of the rib 23 toward the tip side beyond the semi-circle (not shown).

[0061] In this way, by keeping the joining depth not shallow until the arc portion 282 forms at least a semi-circle and the tangent line of the arc portion 282 becomes parallel to the longitudinal direction of the rib 23 toward the tip side beyond the semi-circle, the pressure resistance at the end portion of the rib 23 where stress concentration is likely to occur can be improved.

[0062] Also, in the rib weld bead 28 of the third modification example, the arc portion 282 is formed on the flat portion 231 along the R stop of the curved surface portion connecting the flat portion 231 and the wall portion 232 in the rib 23.

[0063] Thereby, since the pressure receiving area of the flat portion 231 around the arc portion 282 can be reduced, the stress generated around the arc portion 282 can be reduced.

[0064] As described above, the heat exchanger 100 includes a first member 10 and a second member 20 joined by laser welding, and a fluid flow path 27 is formed between the first member 10 and the second member 20. The second member 20 has a rib 23 joined to the first member 10 by laser welding to partition the flow path 27. The rib welding bead 28 joining the rib 23 to the first member 10 has an arcuate portion 282 at its end, and the joining depth becomes shallower toward the tip of the arcuate portion 282 which is the start or end point of the laser welding. In the track of the rib welding bead 28, the leading bead and the trailing bead do not overlap or the joining depth at the tip of the arcuate portion 282 is a depth at which the first member 10 and the second member 20 are not joined.

[0065] According to this, since the end of the rib welding bead 28 where stress concentration is likely to occur due to the internal pressure of the heat exchanger 100 is formed into the arcuate arcuate portion 282, stress concentration at the end of the rib welding bead 28 can be suppressed. Also, since the joining depth is made shallow at the tip of the arcuate portion 282, that is, at the start / end point of the laser welding, the heat input amount can be made appropriate and the welding quality can be improved. Further, when the leading bead and the trailing bead do not overlap in the track of the rib welding bead 28, it is possible to prevent the trailing bead from affecting the joining strength by the leading bead. The same applies when the joining depth at the tip of the arcuate portion 282 is set to a depth at which the first member 10 and the second member 20 are not joined. Even if the tip of the arcuate portion 282 overlaps the leading bead, it is possible to prevent the joining strength by the leading bead from being affected. Therefore, the strength of the heat exchanger 100 manufactured using laser welding can be ensured.

[0066] Also, the arcuate portion 282 forms at least a semi-circle, and the joining depth does not become shallower until the tangent of the arcuate portion 282 becomes parallel to the longitudinal direction of the rib 23 toward the tip side beyond the semi-circle.

[0067] In this way, by forming the arc portion 282 to form at least a semi-circle and keeping the joining depth unchanged until the tangent of the arc portion 282 becomes parallel to the longitudinal direction of the rib 23 toward the tip side beyond the semi-circle, the pressure resistance at the end of the rib 23 where stress concentration is likely to occur can be improved.

[0068] Further, the rib welding bead 28 has a straight portion 281 formed linearly, and the straight portion 281 extends along the longitudinal direction of the rib 23. The straight portion 281 can be formed at the center in the width direction of the rib 23.

[0069] According to this, the stress generated around the straight portion 281 can be evenly dispersed to both sides of the straight portion 281. That is, by forming the straight portion 281 at the center in the width direction of the rib 23, the stress concentration of the straight portion 281 can be suppressed.

[0070] Also, the connecting portion 283 connecting the straight portion 281 and the arc portion 282 may be arc-shaped.

[0071] By making the connecting portion 283 connecting the straight portion 281 and the arc portion 282 arc-shaped, the local increase in laser input at the connecting portion 283 can be suppressed. Therefore, the welding quality can be improved.

[0072] Further, the rib 23 has a flat portion 231 that abuts against the first member 10 and a wall portion 232 that rises from the flat portion 231, and the arc portion 282 of the rib welding bead 28 is formed along the R stop of the curved surface portion connecting the flat portion 231 and the wall portion 232 in the rib 23.

[0073] According to this, the pressure-receiving area of the flat portion 231 around the arc portion 282 can be reduced, so the stress generated around the arc portion 282 can be reduced.

[0074] Also, the heat exchanger 100 has a mounting portion for mounting to the vehicle 200, and the two end portions 261 of the outer peripheral welding bead 26 for joining the outer peripheral portion are located at the mounting portion. The mounting portion is a protruding portion 24 that extends outward from the heat exchanger 100.

[0075] According to this, stress concentration on the two end portions 261 of the outer circumferential weld bead 26 due to the internal pressure of the heat exchanger 100 can be suppressed.

[0076] Further, in a method of manufacturing a heat exchanger 100 including a first member 10 and a second member 20 joined by laser welding, and a fluid flow path 27 is formed between the first member 10 and the second member 20, the second member 20 has a rib 23 joined to the first member 10 by laser welding and partitioning the flow path 27. In the laser welding for forming a rib weld bead 28 joining the rib 23 to the first member 10, an arcuate arc portion 282 is formed at an end portion of the rib weld bead 28, and the joining depth becomes shallower toward the tip of the arc portion 282 which is the start point or the end point of the laser welding. The leading bead and the trailing bead are not overlapped in the trajectory of the rib weld bead 28, or the joining depth at the tip of the arc portion 282 is set to a depth at which the first member 10 and the second member 20 are not joined.

[0077] According to this, since the end portion of the rib weld bead 28 where stress concentration is likely to occur due to the internal pressure of the heat exchanger 100 is formed into the arcuate arc portion 282, stress concentration on the end portion of the rib weld bead 28 can be suppressed. Also, since the joining depth is made shallower at the tip of the arc portion 282, that is, at the start point / end point of the laser welding, the heat input amount can be made appropriate and the welding quality can be improved. Further, when the leading bead and the trailing bead are not overlapped in the trajectory of the rib weld bead 28, it is possible to prevent the trailing bead from affecting the joining strength by the leading bead. The same applies when the joining depth at the tip of the arc portion 282 is set to a depth at which the first member 10 and the second member 20 are not joined. Even if the tip of the arc portion 282 overlaps with the leading bead, it is possible to prevent the joining strength by the leading bead from being affected. Therefore, the strength of the heat exchanger 100 manufactured using laser welding can be ensured.

[0078] As described above, the embodiments of the present invention have been described. However, the above embodiments merely show one of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0079] For example, in the above embodiment, the heat exchanger 100 is used for temperature adjustment of the battery 120. However, the use of the heat exchanger 100 is not limited to this.

[0080] Also, the outer shape of the heat exchanger 100, the shape and number of the ribs 23 can be appropriately changed.

[0081] Also, the outer peripheral welding bead 26 may be divided into a plurality of beads.

Description of Reference Numerals

[0082] 100 Heat exchanger 10 First member 20 Second member 23 Rib 231 Flat portion 232 Wall portion 24 Protrusion (mounting portion) 26 Outer peripheral welding bead 261 End portion 27 Flow path 28 Rib welding bead 281 Straight portion 282 Arc portion 283 Connection portion

Claims

1. A heat exchanger comprising a first member and a second member joined by laser welding, and a fluid flow path formed between the first member and the second member, The second member has ribs joined to the first member by the laser welding to partition the flow path, The rib welding bead joining the ribs to the first member Has an arcuate portion formed in an arc shape at an end, The joining depth becomes shallower toward the tip of the arcuate portion which is the start point or the end point of the laser welding, In the trajectory of the rib welding bead, the leading bead and the trailing bead do not overlap or the joining depth at the tip of the arcuate portion is a depth at which the first member and the second member are not joined, Heat exchanger.

2. The heat exchanger according to claim 1, The arcuate portion forms at least a semi-circle, and the joining depth does not become shallower until the tangent line of the arcuate portion reaches a position where it is parallel to the longitudinal direction of the rib toward the tip side beyond the semi-circle, Heat exchanger.

3. The heat exchanger according to claim 1, The rib welding bead has a straight portion formed in a straight line, The straight portion extends along the longitudinal direction of the rib and is formed at the center in the width direction of the rib, Heat exchanger.

4. The heat exchanger according to claim 3, The connecting portion connecting the straight portion and the arcuate portion is arcuate, Heat exchanger.

5. The heat exchanger according to claim 1, The rib A flat portion in contact with the first member, A wall portion rising from the flat portion, And has, The arc portion of the rib welding bead is formed along the R stop of the curved surface portion that connects the flat portion and the wall portion in the rib. Heat exchanger.

6. A heat exchanger according to any one of claims 1 to 5, having a mounting portion for mounting to an external device, The end portion of the outer peripheral welding bead that joins the outer peripheral portion is located at the mounting portion. Heat exchanger.

7. A heat exchanger according to claim 6, The mounting portion is a protruding portion that extends outward from the heat exchanger. Heat exchanger.

8. A method for manufacturing a heat exchanger including a first member and a second member joined by laser welding, and a fluid flow path being formed between the first member and the second member, The second member has ribs joined to the first member by the laser welding to partition the flow path, In the laser welding for forming a rib welding bead that joins the rib to the first member, An arc-shaped arc portion is formed at an end portion of the rib welding bead, The joining depth becomes shallower toward the tip of the arc portion that is the start point or the end point of the laser welding, In the track of the rib welding bead, the preceding bead and the succeeding bead are not overlapped or the joining depth at the tip of the arc portion is set to a depth at which the first member and the second member are not joined. Method for manufacturing a heat exchanger.

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