Cooling system

Abstract

To provide a technique that can prevent entry of a foreign matter into a metal case.SOLUTION: A cooling system comprises: a blower; a metal case; a semiconductor module that is housed in the metal case and is arranged on a lower surface of an upper wall of the metal case; and a resin duct that is arranged so as to cover at least part of an upper surface of the upper wall of the metal case, and guides cooling air from the blower between an upstream end connected to the blower and a downstream end open to outside along the upper surface of the upper wall. The resin duct includes: a first resin part made of thermoplastic resin; and a second resin part made of thermosetting resin. The second resin part of the resin duct is positioned above the semiconductor module and supported by the first resin part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed in this specification relates to a cooling system.

Background Art

[0002] Patent Document 1 discloses a cooling system including a metal case, a semiconductor module housed in the metal case and disposed on the lower surface of the upper wall of the metal case, and a cooling water flow path provided on the upper wall side of the metal case. In this cooling system, the semiconductor module in the metal case is cooled by the cooling water flowing through the cooling water flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a cooling system, there is a configuration (i.e., an air-cooled type) in which air is used to cool the semiconductor module in the metal case instead of cooling water. In such a configuration, an abnormality may occur in the semiconductor module, causing the semiconductor module to overheat. In this case, the metal case may melt and a hole may be formed in the metal case. If a hole is formed in the metal case, foreign matter may enter the metal case through the hole.

[0005] This specification provides a technology capable of suppressing the intrusion of foreign matter into the metal case.

Means for Solving the Problems

[0006] In a first aspect of the present technology, the cooling system may include a blower, a metal case, a semiconductor module housed within the metal case and disposed on the lower surface of the upper wall of the metal case, and a resin duct disposed to cover at least a part of the upper surface of the upper wall of the metal case, guiding cooling air from the blower along the upper surface of the upper wall between an upstream end connected to the blower and a downstream end open to the outside. The resin duct may include a first resin part made of a thermoplastic resin and a second resin part made of a thermosetting resin. The second resin part of the resin duct may be located above the semiconductor module and supported by the first resin part.

[0007] As described above, when the semiconductor module overheats, the metal case may melt and holes may form in the metal case. In this case, high-temperature gas flows out from the holes in the metal case. According to the above configuration, the gas flowing out from the holes in the metal case causes the first resin part made of thermoplastic resin in the resin duct to melt. On the other hand, the second resin part made of thermosetting resin does not melt. When the first resin part melts, the second resin part located above the semiconductor module drops, and can at least partially block the holes in the metal case. Therefore, the intrusion of foreign matter into the metal case can be suppressed.

[0008] In a second aspect, in the first aspect, a plurality of fins may be provided on the upper surface of the upper wall of the metal case, each extending along a first direction from the upstream end to the downstream end and arranged along a second direction orthogonal to the first direction. The second resin part may include a plurality of resin extension parts each extending along the first direction and arranged along the second direction. Each of the plurality of resin extension parts may be disposed above the space between two adjacent ones of the plurality of fins.

[0009] In the above configuration, when the semiconductor module overheats, it is assumed that a hole is formed between two adjacent fins in the second direction. In this regard, according to the above configuration, when the first resin part melts and the resin extension part of the second resin part drops, the resin extension part can be more reliably dropped between two adjacent fins. Therefore, the hole formed by the melting of the upper wall can be more reliably blocked.

[0010] In a third aspect, in the second aspect, in the first direction, both ends of the resin extension part may be located outside both ends of the semiconductor module.

[0011] The melting of the metal case is caused by the overheating of the semiconductor module. Therefore, when the upper wall of the metal case melts and a hole is formed in the upper wall, it is assumed that the formation of the hole occurs within the range where the semiconductor module is disposed. From this, in the first direction, if both ends of the resin extension part are located outside both ends of the semiconductor module, the hole formed by the melting of the upper wall can be more reliably blocked.

[0012] In a fourth aspect, in the second or third aspect, in the second direction, two located on both sides of the plurality of resin extension parts may be located outside the semiconductor module.

[0013] As described above, when the upper wall of the metal case melts and a hole is formed in the upper wall, it is assumed that the formation of the hole occurs within the range where the semiconductor module is disposed. From this, in the second direction, if two located on both sides of the plurality of resin extension parts are located outside the semiconductor module, the hole formed by the melting of the upper wall can be more reliably blocked.

[0014] In a fifth aspect, in any of the first to fourth aspects, the thermoplastic resin may be polypropylene, and the thermosetting resin may be a phenol resin.

[0015] According to the above configuration, the first resin part can be surely melted while maintaining the shape of the second resin part with respect to the temperature assumed when the upper wall of the metal case melts. Thereby, the hole formed by the melting of the upper wall can be more surely closed.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0017] (Example) As shown in FIG. 1, the cooling system 2 includes an intake duct 10, a blower 12, an exhaust duct 14, and a converter case 16. The cooling system 2 is mounted on an electric vehicle such as an electric vehicle that rotates a drive motor with a battery, a fuel cell vehicle that rotates a drive motor with electric power generated by a fuel cell, or a hybrid vehicle that includes both a drive motor and an internal combustion engine. Hereinafter, for ease of understanding, the extending direction of the exhaust duct 14 is defined as the "front-rear direction", and the "left-right direction" and the "up-down direction" are defined as shown in FIG. 1 with reference to this. Note that the "front-rear direction" and the "left-right direction" defined here do not limit the posture of the cooling system 2 during use.

[0018] (Configuration of the Converter Case 16) The converter case 16 is a metal case. The converter case 16 includes a case bottom wall 20 (see FIG. 2), a case upper wall 22, a case right wall 24 (see FIG. 2), a case left wall 26, a case front wall 28, and a case rear wall (not shown). On the upper surface 22A of the case upper wall 22, a plurality of fins 30 extending in the front-rear direction are provided. The plurality of fins 30 are arranged side by side in the left-right direction. The plurality of fins 30 are arranged at equal intervals in the left-right direction.

[0019] As shown in FIG. 2, a DC-DC converter 40 is housed in the converter case 16. In FIG. 2, the DC-DC converter 40 is shown in a simplified manner. The DC-DC converter 40 includes a plurality of circuit boards 42A, 42B and a plurality of semiconductor modules 44A, 44B. The plurality of semiconductor modules 44A, 44B are attached to the lower surface 22B of the case upper wall 22 of the converter case 16.

[0020] (Configuration of the intake duct 10) The upstream end of the intake duct 10 in FIG. 1 is open to the outside, and the downstream end of the intake duct 10 is connected to the blower 12. The blower 12 sucks cooling air through the intake duct 10 and sends the cooling air to the exhaust duct 14.

[0021] (Configuration of the exhaust duct 14) The exhaust duct 14 is a resin duct. The exhaust duct 14 extends in the front-rear direction. The upstream end (i.e., the rear end) of the exhaust duct 14 is connected to the blower 12, and the downstream end (i.e., the front end) of the exhaust duct 14 is open to the outside. The exhaust duct 14 is arranged so as to cover a part of the upper surface 22A of the case upper wall 22 of the converter case 16. Specifically, the exhaust duct 14 covers the upper surface 22A of the case upper wall 22 in the range where the semiconductor modules 44A, 44B are arranged. The exhaust duct 14 guides the cooling air from the blower 12 along the upper surface 22A between the upstream end and the downstream end.

[0022] The exhaust duct 14 has an upper duct portion 50 and a lower duct portion 52. The upper duct portion 50 extends from the upstream end to the downstream end. The upstream end (i.e., the rear end) of the upper duct portion 50 is connected to the intake duct 10. The position in the front-rear direction of the downstream end (i.e., the front end) of the upper duct portion 50 substantially coincides with the front end of the converter case 16. The lower duct portion 52 is provided between the intake duct 10 and the converter case 16. The lower duct portion 52 is fixed to the upper duct portion 50 from below by screws (not shown) or the like.

[0023] The upper duct portion 50 includes a duct upper wall 60, a duct right wall 62, a duct left wall 64, and side edges 66 provided on both left and right sides of the upper duct portion 50. The right side edge 66 extends rightward from the lower end of the duct right wall 62, and the left side edge 66 extends leftward from the lower end of the duct left wall 64. As shown in FIG. 2, the upper duct portion 50 is composed of a first resin portion 68 made of a thermoplastic resin and a second resin portion 70 made of a thermosetting resin. As an example, the thermoplastic resin is polypropylene, and the thermosetting resin is a phenolic resin. The duct right wall 62, the duct left wall 64, and the side edge 66 are composed of the first resin portion 68. The duct upper wall 60 is composed of the first resin portion 68 and the second resin portion 70. In FIG. 2, the portion made of the first resin portion 68 is hatched, and the portion made of the second resin portion 70 is not hatched. Although not shown, the duct right wall 62 and the duct left wall 64 are fixed to the converter case 16 by screws or the like. The second resin portion 70 includes a plurality of left resin extension portions 80A to 80D extending in the front-rear direction and a plurality of right resin extension portions 82A to 82C. Hereinafter, each of the plurality of left resin extension portions 80A to 80D and the plurality of right resin extension portions 82A to 82C may be collectively referred to as the "left resin extension portion 80" and the "right resin extension portion 82". The left resin extension portion 80 and the right resin extension portion 82 are supported by the first resin portion 68. In this embodiment, the left resin extension portion 80 and the right resin extension portion 82 are embedded inside the first resin portion 68. In a modified example, the left resin extension portion 80 and the right resin extension portion 82 may be provided on the upper surface of the first resin portion 68, or may be adhered to the lower surface of the first resin portion 68 by an adhesive or the like.

[0024] The plurality of left resin extension parts 80A to 80D are arranged above the semiconductor module 44A. The plurality of left resin extension parts 80A to 80D are arranged at equal intervals in the left-right direction. In the left-right direction, each of the plurality of left resin extension parts 80A to 80D is arranged between two adjacent fins 30. The length of the left resin extension part 80 in the left-right direction is slightly shorter than the distance between two adjacent fins 30 in the left-right direction. Note that the length of the left resin extension part 80 in the left-right direction only needs to be shorter than the distance between two adjacent fins 30. The left end of the left resin extension part 80A arranged at the leftmost side is located on the left side of the left end of the semiconductor module 44A. The right end of the left resin extension part 80D arranged at the rightmost side is located on the right side of the right end of the semiconductor module 44A. Referring to FIG. 3, the size of the left resin extension part 80 in the front-rear direction will be described. In FIG. 3, for easy understanding, the semiconductor modules 44A and 44B, the left resin extension part 80, and the right resin extension part 82 are shown by two-dot chain lines. As shown in FIG. 3, both the front and rear ends of the left resin extension part 80 are located outside the front and rear ends of the semiconductor module 44A. That is, the length of the left resin extension part 80 in the front-rear direction is longer than the length of the semiconductor module 44A in the front-rear direction.

[0025] As shown in FIG. 2, the plurality of right resin extension parts 82A to 82C are arranged above the semiconductor module 44B. The plurality of right resin extension parts 82A to 82C are arranged at equal intervals in the left-right direction. In the left-right direction, each of the plurality of right resin extension parts 82A to 82C is arranged between two adjacent fins 30. The length of the right resin extension part 82 in the left-right direction is slightly shorter than the distance between two adjacent fins 30. The left end of the right resin extension part 82A arranged at the leftmost side is located on the left side of the left end of the semiconductor module 44B. The right end of the right resin extension part 82C arranged at the rightmost side is located on the right side of the right end of the semiconductor module 44B. As shown in FIG. 3, both the front and rear ends of the right resin extension part 82 are located outside the front and rear ends of the semiconductor module 44B. That is, the length of the right resin extension part 82 in the front-rear direction is longer than the length of the semiconductor module 44B in the front-rear direction. In this embodiment, the shapes and sizes of the left resin extension part 80 and the right resin extension part 82 are the same, but in a modified example, the shapes and sizes of the left resin extension part 80 and the right resin extension part 82 may be different.

[0026] (Effects of the first resin part 68 and the second resin part 70) Referring to FIGS. 4 and 5, the effects of the first resin part 68 and the second resin part 70 will be described. In FIGS. 4 and 5, a situation where the semiconductor module 44A melts due to overheating of the semiconductor module 44A is assumed. FIG. 4(A) shows the state immediately before the semiconductor module 44A melts. In FIGS. 4 and 5, the left resin extension part 80 and the right resin extension part 82 are shown in gray.

[0027] As shown in FIG. 4(B), when the semiconductor module 44A overheats, the semiconductor module 44A melts. Also, the portion of the case upper wall 22 of the converter case 16 that was in contact with the semiconductor module 44A melts. As a result, a hole 90 that communicates the outside with the inside of the converter case 16 is formed in the case upper wall 22 of the converter case 16. Then, the high-temperature gas rises through the hole 90 (arrow F in FIG. 4(B)).

[0028] As shown in Fig. 5(C), when high-temperature gas reaches the duct upper wall 60 of the upper duct portion 50, the portion (i.e., thermoplastic resin) constituted by the first resin portion 68 of the duct upper wall 60 melts. On the other hand, the portion (i.e., thermosetting resin) constituted by the second resin portion 70 of the duct upper wall 60 does not melt. As a result, the plurality of left resin extension portions 80A to 80D of the second resin portion 70 are no longer supported by the first resin portion 68, and the plurality of left resin extension portions 80A to 80D drop down.

[0029] As shown in Fig. 5(D), the dropped plurality of left resin extension portions 80A to 80D are placed on the upper surface 22A of the case upper wall 22 of the converter case 16. That is, the holes 90 formed by the melting of the case upper wall 22 are blocked by the plurality of left resin extension portions 80A to 80D. For this reason, it is possible to suppress (conductive) foreign matter from passing through the holes 90 and entering the converter case 16.

[0030] (Effect of this embodiment) As described above, as shown in Figs. 1 to 3, a cooling system 2, a blower 12, a converter case 16 (an example of a "metal case"), a semiconductor module 44A housed in the converter case 16 and disposed on the lower surface 22B of the case upper wall 22 of the converter case 16, and an exhaust duct 14 (an example of a "resin duct") disposed so as to cover at least a part of the upper surface 22A of the case upper wall 22 of the converter case 16 and guiding the cooling air from the blower 12 along the upper surface 22A of the case upper wall 22 between the upstream end connected to the blower 12 and the downstream end opened to the outside. The exhaust duct 14 includes a first resin portion 68 made of a thermoplastic resin and a second resin portion 70 made of a thermosetting resin. The second resin portion 70 of the exhaust duct 14 is located above the semiconductor modules 44A and 44B and is supported by the first resin portion 68.

[0031] As shown in FIGS. 4 and 5, when the semiconductor module 44A overheats, the converter case 16 may melt and holes 90 may be formed in the converter case 16. In this case, high-temperature gas flows out from the holes 90 in the converter case 16. According to the above configuration, the gas flowing out from the holes 90 in the converter case 16 melts the first resin portion 68 made of a thermoplastic resin in the exhaust duct 14. On the other hand, the second resin portion 70 made of a thermosetting resin does not melt. When the first resin portion 68 melts, the second resin portion 70 located above the semiconductor module 44A drops, and can at least partially block the holes 90 in the converter case 16. Therefore, the intrusion of foreign matter into the converter case 16 can be suppressed.

[0032] Also, as shown in FIG. 1, on the upper surface 22A of the case upper wall 22 of the converter case 16, a plurality of fins 30 are provided that each extend along the front-rear direction (an example of the "first direction") from the upstream end to the downstream end and are arranged along the left-right direction (an example of the "second direction"). As shown in FIG. 2, the second resin portion 70 includes a plurality of left resin extension portions 80 that each extend along the front-rear direction and are arranged along the left-right direction. Each of the plurality of left resin extension portions 80 is disposed above the space between two adjacent ones of the plurality of fins 30.

[0033] In the above configuration, when the semiconductor module 44A overheats, it is assumed that holes 90 are formed between two adjacent fins 30 in the left-right direction. In this regard, according to the above configuration, when the first resin portion 68 melts and the left resin extension portion 80 of the second resin portion 70 drops, the left resin extension portion 80 can be more reliably dropped between two adjacent fins 30. Therefore, the holes 90 formed by the melting of the case upper wall 22 can be more reliably blocked.

[0034] Also, as shown in FIG. 3, in the front-rear direction, both ends of the left resin extension portion 80 are located outside both ends of the semiconductor module 44A.

[0035] The melting of the converter case 16 is caused by the overheating of the semiconductor module 44A. Therefore, when the upper wall 22 of the case of the converter case 16 melts and a hole 90 is formed in the upper wall 22 of the case, it is assumed that the formation of the hole 90 occurs within the range where the semiconductor module 44A is disposed. From this, in the front-rear direction, if both ends of the left resin extension portion 80 are located outside both ends of the semiconductor module 44A, the hole 90 formed by the melting of the upper wall 22 of the case can be more reliably blocked.

[0036] Also, as shown in FIG. 2, in the left-right direction, the two located on both sides of the left resin extension portion 80 are located outside the semiconductor module 44A.

[0037] In the left-right direction, if the two located on both sides of the left resin extension portion 80 are located outside the semiconductor module 44A, the hole 90 formed by the melting of the upper wall 22 of the case can be more reliably blocked.

[0038] Also, the thermoplastic resin is polypropylene, and the thermosetting resin is phenol resin.

[0039] According to the above configuration, the first resin portion 68 can be surely melted while maintaining the shape of the second resin portion 70 with respect to the temperature assumed when the upper wall 22 of the converter case 16 melts. Thereby, the hole 90 formed by the melting of the upper wall 22 of the case can be more reliably blocked.

[0040] As described above, specific examples of the technology disclosed in this specification have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples exemplified above.

[0041] (First Modification Example) The fins 30 may not be provided on the case upper wall 22 of the converter case 16. In this modification example, the size of the cross-sectional shape of the second resin portion 70 orthogonal to the vertical direction is larger than the size of the cross-sectional shape of the semiconductor module 44A. In another modification example, in the configuration where the fins 30 are not provided on the case upper wall 22 of the converter case 16, the size of the cross-sectional shape of the second resin portion 70 orthogonal to the vertical direction may be smaller than the size of the cross-sectional shape of the semiconductor module 44A.

[0042] (Second Modification Example) At least one of the front and rear ends of the left resin extension portion 80 may be located inside the front and rear ends of the semiconductor module 44A.

[0043] (Third Modification Example) The second resin portion 70 may not include at least one of the left resin extension portion 80A located on the leftmost side and the left resin extension portion 80D located on the rightmost side.

[0044] (Fourth Modification Example) The right resin extension portion 82 may not be provided above the semiconductor module 44B.

[0045] (Fifth Modification Example) "Thermoplastic resin" and "thermosetting resin" are not limited to polypropylene and phenolic resin, respectively.

[0046] Also, the technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Also, the technology exemplified in this specification or the drawings can achieve multiple purposes simultaneously, and achieving one of those purposes itself has technical utility.

Explanation of Reference Numerals

[0047] 2: Cooling system, 10: Intake duct, 12: Blower, 14: Exhaust duct, 16: Converter case, 20: Case bottom wall, 22: Case upper wall, 22A: Upper surface, 22B: Lower surface, 24: Case right wall, 26: Case left wall, 28: Case front wall, 30: Fin, 40: DC-DC converter, 42A: Circuit board, 42B: Circuit board, 44A: Semiconductor module, 44B: Semiconductor module, 50: Upper duct portion, 52: Lower duct portion, 60: Duct upper wall, 62: Duct right wall, 64: Duct left wall, 66: Side edge, 68: First resin portion, 70: Second resin portion, 80: Left resin extension, 82: Right resin extension, 90: Hole

Claims

**Claim 1** A cooling system comprising a blower, a metal case, a semiconductor module housed within the metal case and disposed on the lower surface of the upper wall of the metal case, a resin duct disposed so as to cover at least a part of the upper surface of the upper wall of the metal case, guiding cooling air from the blower along the upper surface of the upper wall between an upstream end connected to the blower and a downstream end open to the outside, wherein the resin duct includes a first resin portion made of a thermoplastic resin and a second resin portion made of a thermosetting resin, the second resin portion of the resin duct is located above the semiconductor module and is supported by the first resin portion, the cooling system. **Claim 2** On the upper surface of the upper wall of the metal case, a plurality of fins are provided, each extending along a first direction from the upstream end toward the downstream end and arranged along a second direction orthogonal to the first direction, the second resin portion includes a plurality of resin extension portions, each extending along the first direction and arranged along the second direction, each of the plurality of resin extension portions is disposed above a space between two adjacent ones of the plurality of fins. The cooling system according to claim 1. **Claim 3** In the first direction, both ends of the resin extension portion are located outside both ends of the semiconductor module. The cooling system according to claim 2. **Claim 4** In the second direction, two of the plurality of resin extension portions located on both sides are located outside the semiconductor module. The cooling system according to claim 3. **Claim 5** The thermoplastic resin is polypropylene, the thermosetting resin is a phenolic resin. The cooling system according to claim 1.

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