Power conversion device and vehicle charging device

Abstract

To provide a technique capable of efficiently performing cooling.SOLUTION: A power conversion device 2 includes: a housing 6 that accommodates an electric circuit group 14 therein; and a heat sink 20 that is provided on a rear side surface 6c of the housing 6 and being thermally connected to the electric circuit 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a power conversion device and a vehicle charging device. [Background technology]

[0002] Patent Document 1 discloses an installed power conversion device. The housing of this power conversion device has a partition wall inside. The partition wall separates the internal space of the housing into a circuit component housing space and a duct space. A fan and a heat sink are provided in the duct space. The fan takes air into the duct space. Heat generated by the circuit components in the circuit component housing space is conducted to the heat sink. The heat sink is air-cooled by the air in the duct space. This cools the circuit components in the circuit component housing space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-36456 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the heat sink of the power conversion device of the above-mentioned conventional example is provided inside the housing, the heat dissipation performance of the heat sink cannot be said to be high, and there is a concern that the cooling of the circuit components will not be performed efficiently. Therefore, an object of the present disclosure is to provide a technique that enables efficient cooling. [Means for solving the problem]

[0005] A power conversion device according to an embodiment includes a housing that houses an electric circuit therein, and a heat sink that is provided on an outer surface of the housing and thermally connected to the electric circuit. [Effects of the Invention]

[0006] According to the present disclosure, efficient cooling can be achieved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing an example of a vehicle charging device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the vehicle charging device. [Figure 3] FIG. 3 is a view showing the main part of the rear side of the housing. [Figure 4] FIG. 4 is a partial cross-sectional view of the power converter, taken along line IV-IV in FIG. [Figure 5] FIG. 5 is an enlarged view of the tips of the pair of first fins in FIG. [Figure 6] FIG. 6 is a partial cross-sectional view of a power converter according to a modified example. [Figure 7] FIG. 7 is a partial cross-sectional view of a power converter according to another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] First, the contents of the embodiment will be listed and explained. [Outline of the embodiment]

[0009] (1) A power conversion device according to an embodiment of the present disclosure includes a housing that houses an electric circuit therein, and a heat sink that is provided on an outer surface of the housing and thermally connected to the electric circuit.

[0010] According to the above configuration, since the heat sink is provided on the outer surface of the housing, the heat sink dissipates heat to the air outside the housing. Therefore, the heat dissipation performance of the heat sink can be improved compared to when the heat sink is provided inside the housing. As a result, the heat sink can efficiently cool the electric circuit.

[0011] (2) In the power conversion device of (1) above, when a cover that covers the heat sink is further provided, the heat sink may have a fixing surface to which the cover is fixed. In this case, since the cover is fixed to the heat sink, there is no need to provide a member for fixing the cover to the outer surface of the housing.

[0012] (3) In the power conversion device of (2) above, when the heat sink has a plate-shaped base provided on the outer surface and a plurality of fins protruding from the base and extending along a first direction parallel to the outer surface, the plurality of fins may have one or more first fins having the fixing surface at their tips and a plurality of second fins having a protruding height shorter than that of the one or more first fins. In this case, the cover is supported by the first fins, and a gap can be provided between the tips of the second fins and the cover. This allows the amount of air flowing between the base and the cover to be increased while maintaining the flow rate of the air between the base and the cover, thereby further improving the heat dissipation performance of the second fins.

[0013] (4) In the power converter of (3) above, a difference in height between a protruding height of the one or more first fins and a protruding height of the plurality of second fins may be 0.2 mm or more and 3 mm or less. If the height difference is less than 0.2 mm, it may be difficult to ensure a sufficient amount of air flowing between the base and the cover. If the height difference is more than 3 mm, it may be difficult to increase the flow rate of the air flowing between the base and the cover as much as necessary. By setting the height difference to between 0.2 mm and 3 mm, it is possible to appropriately set the amount and flow rate of the air flowing between the base and the cover.

[0014] (5) In the power converter of (3) or (4) above, the thickness of the one or more first fins may be greater than the thickness of the plurality of second fins. In this case, the second fins are thinner than the first fins, which improves heat dissipation, while the first fins are thicker than the second fins, which improves rigidity and ensures a wider fixing surface, allowing for more appropriate support of the cover.

[0015] (6) Furthermore, in any one of the power conversion devices (3) to (5) above, if the housing has an opening on the outer surface that connects the inside and outside of the housing, the base may be arranged to block the opening. In this case, the openings facilitate thermal connection between the electrical circuitry and the heat sink.

[0016] (7) Furthermore, the power converter of any one of (2) to (6) above may further include a fixing member attached to the heat sink for fixing the cover in contact with the fixing surface. In this case, the cover can be fixed to the heat sink by the fixing member.

[0017] (8) Furthermore, in the power conversion device of (7) above, if the cover has a cover body made of a conductive metal and a coating layer covering the surface of the cover body, the surface of the cover has a painted surface covered by the coating layer and an exposed surface on which the cover body is exposed, and the fixing member has a clamping portion that clamps the cover between itself and the fixing surface, the exposed surface may be provided on the portion of the surface of the cover that abuts the clamping portion. In this case, if it is desired to ground the cover, by connecting the heat sink to a ground conductor on the housing side, the cover body can be grounded via the fixing member and the heat sink.

[0018] (9) Furthermore, in any one of the power conversion devices (3) to (8) above, among the plurality of fins arranged along a second direction that intersects the first direction and is parallel to the outer surface, a pair of fins located at both ends of the second direction may each be the first fin, and the cover may have a main body plate that connects between a pair of fixing surfaces of the pair of first fins. In this case, a cylindrical duct is formed by the base, the pair of first fins, and the main body plate, so that when airflow is provided in the space between the base and the cover, the airflow can be appropriately guided to the second fins.

[0019] (10) Furthermore, in the power conversion device of (9) above, when the main body plate has a pair of first edges along the first direction, the cover may further have a pair of side plates extending from the edges of the pair of first edges and facing the side surfaces of the pair of first fins. In this case, the side surfaces of the pair of first fins can also be covered with the cover, and when air flow is provided in the space between the base and the cover, the air flow can also be directed to the side surfaces of the pair of first fins.

[0020] (11) Another embodiment is a vehicle charging device. The vehicle charging device includes a power conversion device and a charging cable connected to a vehicle and configured to provide the vehicle with power output from the power conversion device. The power conversion device includes a housing that houses an electric circuit therein, and a heat sink that is provided on an outer surface of the housing and thermally connected to the electric circuit.

[0021] [Details of the embodiment] Preferred embodiments will now be described with reference to the drawings. At least some of the embodiments described below may be combined in any manner. FIG. 1 is a perspective view showing an example of a vehicle charging device according to an embodiment. In FIG. 1, a vehicle charging device 1 has a function of charging an on-board battery of an electrically powered vehicle, including an electric vehicle, a hybrid vehicle, or the like.

[0022] The vehicle charging device 1 includes a power conversion device 2 and a power supply cable 4. The power conversion device 2 outputs DC power to be supplied to the vehicle battery. The power conversion device 2 is connected to a commercial power system. The power conversion device 2 converts AC power from the commercial power system into DC power, further converts the power to a required voltage, and outputs the DC power to be supplied to the vehicle battery.

[0023] The power feed cable 4 includes a cable body 4a, a power feed connector 4b, and a connecting connector 4c. The cable body 4a is a power line for transmitting DC power output by the power converter 2. The power feed connector 4b and the connecting connector 4c are provided at both ends of the cable body 4a. That is, the cable body 4a connects the power feed connector 4b and the connecting connector 4c. The connecting connector 4c is connected to the output connector 2a of the power converter 2. The output connector 2a is a connector from which DC power from the power converter 2 is output. The power feed connector 4b can be connected to a power receiving socket of an electric vehicle. When charging the on-board battery of the electric vehicle, the power feed connector 4b is connected to the socket of the electric vehicle. As a result, the DC power from the power converter 2 is supplied to the on-board battery via the power feed cable 4.

[0024] The power conversion device 2 is installed on an installation surface R. The installation surface R is a road surface or a floor surface of a charging space for an electric vehicle or the like. In the following description, the three mutually orthogonal directions in each drawing are referred to as the X direction, Y direction, and Z direction. Also, as shown in FIG. 1, one of the X directions is referred to as the X1 direction, and the opposite direction of the X1 direction is referred to as the X2 direction. One of the Y directions is referred to as the Y1 direction, and the opposite direction of the Y1 direction is referred to as the Y2 direction. One of the Z directions is referred to as the Z1 direction, and the opposite direction of the Z1 direction is referred to as the Z2 direction. The Z direction indicates the height direction of the power converter 2. The X direction indicates the left-right direction of the power converter 2. The Y direction indicates the front-rear direction of the power converter 2.

[0025] In this embodiment, the surface of the power converter 2 facing the Y1 direction is the front surface, and the surface of the power converter 2 facing the Y2 direction is the rear surface. The Z1 direction is the upward direction, and the Z2 direction is the downward direction. 1, the power converter 2 has a rectangular parallelepiped shape with its long sides aligned along the Z direction. The power feed cable 4 is provided on the X2 direction side of the power converter 2.

[0026] FIG. 2 is an exploded perspective view of the vehicle charging device 1. As shown in FIG. As shown in FIG. 2, the power converter 2 includes a housing 6, legs 7, and a decorative cover 8. The housing 6 is placed on an installation surface R. The housing 6 is supported on the installation surface R by legs 7. The housing 6 has a case body 10 and a lid 12. The case body 10 is a box-shaped member made of metal such as steel plate or aluminum alloy. The case body 10 has an opening 10a on the surface facing the Y1 direction. Therefore, the case body 10 has a first lateral side surface 6a, a second lateral side surface 6b, a rear side surface 6c, and a top surface 6d of the housing 6. The first lateral side surface 6a is the surface of the outer surface of the housing 6 facing the X2 direction. The second lateral side surface 6b is the surface of the outer surface of the housing 6 facing the X1 direction. The rear side surface 6c is the surface of the outer surface of the housing 6 facing the Y2 direction. The output connector 2a is provided at the upper end of the first lateral side surface 6a.

[0027] The lid 12 is a plate-like member made of metal such as steel plate or aluminum alloy. The lid 12 is attached to the surface of the case body 10 facing the Y1 direction. Therefore, the lid 12 has a front side surface 6e of the housing 6. The front side surface 6e is the surface of the outer surface of the housing 6 facing the Y1 direction. When attached to the case body 10, the lid 12 closes the opening 10a. Waterproof packing is provided between the lid 12 and the edge of the opening 10a. Waterproof packing and sealing members are also provided in openings for attaching bolts provided in the lid 12 and the case body 10. This allows the housing 6 to function as a waterproof case. An electric circuit group 14 required for power conversion and voltage boosting is housed inside the housing 6. By being housed inside the housing 6, the electric circuit group 14 is made waterproof.

[0028] The decorative cover 8 is a box-shaped member made of metal such as steel plate or aluminum alloy, etc. The decorative cover 8 is attached to the housing 6 so as to cover the outside thereof. The decorative cover 8 has a first side plate 8a, a second side plate 8b, a front plate 8c, and a top plate 8d. The first side plate 8a is disposed on the X2 side of the housing 6. The second side plate 8b is disposed on the X1 side of the housing 6. There is a slight gap between the inner surface of each plate of the decorative cover 8 and each surface of the housing 6.

[0029] A connector holder 16 and a cable holder 18 are provided on the first side plate 8a. The connector holder 16 has a function of holding the power supply connector 4b. When power is not being supplied to the electric vehicle, the power supply connector 4b is held by the connector holder 16. The cable holder 18 has a function of holding the cable main body 4a. When power is not supplied to the electric vehicle, the cable main body 4a is held by the cable holder 18.

[0030] The power conversion device 2 further includes a heat sink 20, a heat sink cover 22, and a fan unit 24. The heat sink 20 is provided on the rear side surface 6c of the housing 6. The heat sink cover 22 is provided to cover the heat sink 20.

[0031] The fan unit 24 includes a pair of fans 24a and a fan cover 24b. The fan cover 24b holds the pair of fans 24a. The fan cover 24b is fixed to the heat sink cover 22 and the rear side surface 6c. The fan cover 24b is fixed above the heat sink 20. The heat sink cover 22 guides the airflow generated by the pair of fans 24a to the heat sink 20. This provides the heat sink 20 with the airflow generated by the pair of fans 24a.

[0032] The heat sink cover 22 is fixed to the heat sink 20 and the bracket 26 by eight first screws 28 and two second screws 30. The bracket 26 is a member made of a metal such as a steel plate or an aluminum alloy, and is interposed between the heat sink cover 22 and the rear side surface 6c. The eight first screws 28 are threaded into eight female threads (described later) provided on the heat sink 20. The two second screws 30 are threaded into bolts fixed to the bracket 26.

[0033] The heat sink 20 is fixed to the rear side surface 6c of the housing 6 by screws, an adhesive layer, or the like. Fig. 3 is a diagram showing a main part of the rear side surface 6c of the housing 6. Fig. 3 shows the rear side surface 6c with the heat sink 20 removed. In Fig. 3, the dashed line L indicates the outline of the heat sink 20. Therefore, the heat sink 20 abuts against a rectangular area enclosed by the dashed line L on the rear side surface 6c.

[0034] The case body 10 of the housing 6 has a rear plate 32 that forms the rear side surface 6c. The rear plate 32 has two openings 34. The two openings 34 are rectangular and communicate with the inside and outside of the housing 6. The two openings 34 are located within a rectangular area surrounded by dashed line L. Therefore, the two openings 34 are closed by the heat sink 20. Note that a waterproofing treatment is applied between the heat sink 20 and the rear side surface 6c using an adhesive layer, a gasket made of an elastic material, or the like.

[0035] Some of the circuits in the electric circuit group 14 inside the housing 6 are fixed to the heat sink 20. Therefore, electric circuits 14a and 14b, which are part of the electric circuit group 14, are exposed from the two openings 34.

[0036] FIG. 4 is a partial cross-sectional view of the power converter 2, taken along line IV-IV in FIG. The heat sink 20 is a heat dissipation member made of an aluminum alloy, a copper alloy, etc. The heat sink 20 has a base 40 and a plurality of fins 42. The base 40 has a rectangular plate shape along the XZ plane. The long sides of the base 40 are aligned in the Z direction (FIG. 2). The first surface 40a of the base 40 is flat and abuts against the rear side surface 6c. The base 40 closes the opening 34 in the rear side surface 6c. The electrical circuit 14b inside the housing 6 is fixed to a portion of the first surface 40a that corresponds to the opening 34.

[0037] The electric circuit 14b has a heat dissipation surface 14b1. When the electric circuit 14b is fixed to the first surface 40a, the first surface 40a and the heat dissipation surface 14b1 are disposed opposite to each other. The electric circuit 14b and the base 40 are thermally connected. Therefore, the first surface 40a and the heat dissipation surface 14b1 may be in direct contact with each other, or a sheet or the like made of a thermally conductive material may be interposed between the first surface 40a and the heat dissipation surface 14b1. In this way, the electric circuit 14b and the base 40 are connected in a manner that allows heat conduction. The heat generated by the electric circuit 14b is conducted to the heat sink 20. The heat sink 20 dissipates the conducted heat. As a result, the electric circuit 14b is cooled by the heat sink 20.

[0038] The housing 6 of this embodiment has an opening 34 on the rear side surface 6c, and the base 40 is provided to close the opening 34, making it easy to thermally connect the electric circuit 14b and the heat sink 20.

[0039] The multiple fins 42 are provided on the second surface 40b side of the base 40. The second surface 40b is the surface opposite to the first surface 40a. The multiple fins 42 protrude in the Y2 direction from the second surface 40b.

[0040] The fins 42 extend along the Z direction (first direction) parallel to the rear side surface 6c. The fins 42 are also aligned along the X direction (second direction). The fins 42 extend parallel to one another.

[0041] The plurality of fins 42 includes a pair of first fins 44 and a plurality of second fins 46 . The pair of first fins 44 are located at both ends in the X direction of the plurality of fins 42. The pair of first fins 44 are provided along both edge portions of the base 40 on the long side thereof. The multiple second fins 46 are provided between the pair of first fins 44. The protruding height of the multiple second fins 46 is lower than the protruding height of the pair of first fins 44. The protruding height of the second fin 46 (first fin 44) is the length along the Y direction from the second surface 40b to the tip of the second fin 46 (first fin 44).

[0042] The tips 44a of the pair of first fins 44 each have a fixing surface 50. The fixing surface 50 is a surface along the XZ plane and is provided over the entire area of ​​the tips 44a. The heat sink cover 22 is fixed to the fixing surface 50.

[0043] The heat sink cover 22 is a plate-like member made of a conductive metal such as a steel plate or an aluminum alloy. The heat sink cover 22 is disposed opposite the rear side surface 6c. The heat sink cover 22 has a main body plate 56 and a pair of side plates 58. The main body plate 56 is a member having a rectangular plate shape along the XZ plane. The main body plate 56 has a long side (first side) along the Z direction (FIG. 2). The main body plate 56 also has a short side along the X direction. The height position of the lower short side of the main body plate 56 is lower than the lower end of the heat sink 20. The height position of the upper short side of the main body plate 56 is the same as the height position of the upper end of the heat sink 20. The main body plate 56 abuts against both of the pair of fixing surfaces 50. Therefore, the main body plate 56 connects the pair of fixing surfaces 50.

[0044] The edges of the long sides of the main body plate 56 protrude outward beyond the pair of first fins 44 . The pair of side plates 58 extend from the edges of the long sides of the main body plate 56 toward the rear side surface 6c. The pair of side plates 58 and the side surfaces 44b of the pair of first fins 44 face each other with a small gap between them. There is also a small gap between the tips of the pair of side plates 58 and the rear side surface 6c.

[0045] A plurality of through holes 56a are provided in the main body plate 56. The plurality of through holes 56a are arranged along the edge of the long side of the main body plate 56. The above-mentioned eight first screws 28 are inserted into the plurality of through holes 56a (FIG. 2). Therefore, in this embodiment, there are eight through holes 56a.

[0046] The tip ends 44 a of the pair of first fins 44 each have a fixing surface 50 and a plurality of female thread portions 52 . The plurality of female thread portions 52 are recessed relative to the fixing surface 50. The plurality of female thread portions 52 are provided corresponding to the eight through holes 56a of the heat sink cover 22. In this embodiment, four female thread portions 52 are provided on each of the tips 44a of the pair of first fins 44.

[0047] The eight first screws 28 are inserted into the through holes 56a and attached to the female threaded portions 52. As a result, the first screws 28 abut and fix the heat sink cover 22 to the pair of fixing surfaces 50. That is, the first screws 28 are attached to the heat sink 20 and constitute fixing members that abut and fix the heat sink cover 22 to the pair of fixing surfaces 50 .

[0048] According to the above configuration, the heat sink 20 is provided on the rear side surface 6c (outer surface) of the housing 6, and therefore the heat sink 20 dissipates heat to the air outside the housing 6. Therefore, the heat dissipation performance of the heat sink can be improved compared to when the heat sink is provided inside the housing. As a result, the heat sink can efficiently cool the electric circuit.

[0049] In addition, in this embodiment, the pair of first fins 44 have fixing surfaces 50 to which the heat sink cover 22 is fixed, so that the heat sink cover 22 can be fixed to the heat sink 20, and there is no need to provide a member for fixing the heat sink cover 22 to the rear side surface 6c of the housing 6. Furthermore, there is no need to provide a through-hole or the like in the rear side surface 6c of the housing 6 in order to fix the heat sink cover 22, and the heat sink cover 22 can be fixed without reducing the waterproofness of the housing 6.

[0050] The fan unit 24 of the present embodiment is configured to provide airflow between the base 40 and the heat sink cover 22. Therefore, the multiple fins 42 of the heat sink 20 dissipate heat in response to the airflow provided by the fan unit 24. Furthermore, the air flow caused by the fan unit 24 is provided between the base 40 and the heat sink cover 22, so that the flow rate of the provided air is maintained at an appropriate level.

[0051] The multiple fins 42 of this embodiment include a pair of first fins 44 having fixing surfaces 50 at their tips 44a, and multiple second fins 46 that protrude lower than the pair of first fins 44. Therefore, the pair of first fins 44 support the heat sink cover 22 against the base 40 and the rear side surface 6c. Also, a gap can be provided between the tips of the multiple second fins 46 and the heat sink cover 22. This allows the amount of air flowing between the base 40 and the heat sink cover 22 to be increased while maintaining the flow velocity of the air, thereby further improving the heat dissipation performance of the multiple second fins 46.

[0052] Here, the height difference Δh between the protruding height of the pair of first fins 44 and the protruding height of the plurality of second fins 46 is preferably 0.2 mm or more and 3 mm or less. In this case, even if dimensional errors occur in the first fins 44 and the second fins 46 when manufacturing the heat sink 20, interference of the second fins 46 with the heat sink cover 22 can be prevented. The protruding height of the pair of first fins 44 is set to, for example, about 20 mm to 60 mm. The protruding height of the plurality of second fins 46 is set to, for example, about 17 mm to 59.8 mm. The protruding heights of the first fins 44 and the second fins 46 are not limited to these values.

[0053] Furthermore, if the height difference Δh is less than 0.2 mm, the second fins 46 may interfere with the heat sink cover 22, and the amount of air flowing between the base 40 and the heat sink cover 22 may not be sufficient. If the height difference Δh is greater than 3 mm, it may be difficult to increase the flow rate of the air flowing between the base 40 and the heat sink cover 22 as required. By setting the height difference Δh to be 0.2 mm or more and 3 mm or less, the amount and flow rate of the air flowing between the base 40 and the heat sink cover 22 can be appropriately set. Furthermore, by setting the height difference Δh to be greater than 0.2 mm, the heat sink cover 22 can be attached without interfering with the second fins 46, even if there is variation in the protruding height of the second fins 46, thereby improving assembly ease.

[0054] As shown in FIG. 4, the thickness of the pair of first fins 44 in this embodiment is greater than the thickness of the plurality of second fins 46. This allows the second fins 46 to have higher heat dissipation properties than the first fins 44. On the other hand, the first fins 44 are thicker than the second fins 46, which increases rigidity and ensures a wider fixing surface 50, allowing the heat sink cover 22 to be supported more appropriately.

[0055] In this embodiment, among the multiple fins 42, a pair of fins 42 located at both ends in the X direction are first fins 44, and the heat sink cover 22 has a main body plate 56 that connects between the pair of fixing surfaces 50 of the pair of first fins 44. Therefore, a cylindrical duct is formed by the base 40, the pair of first fins 44, and the main body plate 56. Therefore, the air flow given to the space between the base 40 and the heat sink cover 22 can be appropriately guided to the multiple second fins. Furthermore, since the heat sink cover 22 of this embodiment has a pair of side plates 58, the side surfaces 44b of the pair of first fins 44 can also be covered by the heat sink cover 22, and air flow can also be directed to the side surfaces 44b of the pair of first fins 44.

[0056] FIG. 5 is an enlarged view of the tips 44a of the pair of first fins 44 in FIG. As described above, the through-hole 56a is provided in (the main body plate 56 of) the heat sink cover 22. Furthermore, the first fin 44 has a female screw portion 52 at its tip 44a.

[0057] The first screw 28 is a member made of a conductive metal such as steel or an aluminum alloy, and has an externally threaded portion 28a and a head 28b. The externally threaded portion 28a is inserted into the through-hole 56a and is screwed into the internally threaded portion 52. Therefore, when the first screw 28 is tightened, the head 28b comes into contact with the surface of the heat sink cover 22. When the first screw 28 is tightened further, the heat sink cover 22 is sandwiched between the head 28b and the fixing surface 50. In other words, the head portion 28b constitutes a clamping portion that clamps the heat sink cover 22 between itself and the fixing surface 50.

[0058] As shown in FIG. 5, the heat sink cover 22 has a cover body 60 and a coating layer 62. The cover body 60 is made of a conductive metal such as a steel plate or an aluminum alloy. The coating layer 62 is formed by painting the surface of the cover body 60. The coating layer 62 has the function of preventing corrosion of the cover body 60. The coating layer 62 is not conductive. The surface 22a of the heat sink cover 22 has a painted surface 22a1 and an exposed surface 22a2. The painted surface 22a1 is the surface covered with the coating layer 62. The exposed surface 22a2 is the surface where the cover body 60 is exposed to the outside.

[0059] In this embodiment, the exposed surface 22a2 is provided on the portion of the surface 22a of the heat sink cover 22 that abuts the head 28b. In other words, the exposed surface 22a2 is provided around the through-hole 56a on the surface facing the Y2 direction of the main body plate 56. The exposed surface 22a2 is circular and has a diameter larger than that of the head 28b. The exposed surfaces 22a2 may be provided to correspond to all of the plurality of through holes 56a, or may be provided to correspond to some of the plurality of through holes 56a.

[0060] The exposed surface 22a2 allows the head portion 28b to be in direct contact with the cover body 60. Therefore, the heat sink 20 and the heat sink cover 22 are electrically connected via the first screw . In this way, by providing the exposed surface 22a2, if it is desired to ground the heat sink cover 22, the cover body 60 can be grounded via the first screw 28 (fixing member) and the heat sink 20 by connecting the heat sink 20 to the grounding conductor on the housing 6 side.

[0061] FIG. 6 is a partial cross-sectional view of a power converter 2 according to a modified example. The modified example shown in FIG. 6 differs from the above embodiment in that the heat sink cover 22 is made up of only a main body plate 56 and does not have a pair of side plates 58. In this modification, the side surfaces 44b of the pair of first fins 44 are exposed to the outside. However, a cylindrical duct is formed by the base 40, the pair of first fins 44, and the main body plate 56. Therefore, the airflow provided in the space between the base 40 and the heat sink cover 22 can be appropriately guided to the multiple second fins 46.

[0062] FIG. 7 is a partial cross-sectional view of a power converter 2 according to another modified example. The modified example shown in FIG. 7 differs from the above embodiment in that one first fin 44 is provided in the center of the base 40 in the X direction, and the heat sink cover 22 is supported by one first fin 44. In this modification as well, the airflow provided in the space between the base 40 and the heat sink cover 22 can be appropriately guided to the plurality of second fins 46.

[0063] 〔others〕 It should be noted that the embodiments disclosed herein are to be considered as illustrative in all respects and not restrictive. In each of the above embodiments, the heat sink 20 is provided on the rear side surface 6c, but the heat sink 20 may also be provided on other outer surfaces, such as the first lateral side surface 6a or the second lateral side surface 6b.

[0064] Furthermore, in each of the above embodiments, the vehicle charging device 1 is provided with the heat sink cover 22, but the vehicle charging device 1 may also be configured without the heat sink cover 22. Even in a configuration without the heat sink cover 22, the heat sink 20 is provided on the rear side surface 6c of the housing 6, so the heat dissipation performance of the heat sink 20 is improved, and the heat sink 20 can efficiently cool the electrical circuit group 14. Furthermore, in each of the above embodiments, the heat sink cover 22 covers the entire heat sink 20 , but the heat sink cover 22 may cover only a part of the heat sink 20 .

[0065] Furthermore, in each of the above embodiments, the vehicle charging equipment 1 including the fan unit 24 has been exemplified, but the vehicle charging equipment 1 may also be configured without the fan unit 24.

[0066] In addition, in each of the above embodiments, the first screws 28 are used as fixing members for fixing the heat sink cover 22 to the pair of fixing surfaces 50. However, the fixing members may be press-fit pins, rivets, or the like, instead of the first screws 28, as long as they can fix the heat sink cover 22 to the fixing surfaces 50.

[0067] The scope of the present invention is defined by the claims, not by the meaning described above, and is intended to include meanings equivalent to the claims and all modifications within the scope thereof. [Explanation of symbols]

[0068] 1. Vehicle charging equipment 2. Power conversion device 2a output connector 4 Power supply cable 4a cable body 4b Power supply connector 4c connection connector 6. Housing 6a First lateral surface 6b Second lateral surface 6c Posterior side 6d top surface 6e Front side 7 Legs 8 Design cover 8a 1st side plate 8b 2nd side plate 8c front panel 8d Upper board 10 Case body 10a opening 12 Lid 14 Electrical Circuits 14a Electrical Circuits 14b Electrical Circuits 14b1 Heat radiation surface 16 Connector holder 18 Cable holder 20 Heat sink 22 Heatsink cover 22a surface 22a1 painted surface 22a2 Exposed surface 24 fan units 24a Fan 24b Fan cover 26 Bracket 28 First screw 28a Male thread 28b Head 30 Second screw 32 Rear plate 34 Opening 40 base 40a Page 1 40b 2nd side 42 Finn 44 First Fin 44a tip 44b Side 46 Second Fin 50 Fixed surface 52 Female thread 56 Main board 56a Through hole 58 Side Panel 60 Cover body 62 Coating layer R installation surface

Claims

1. a housing that houses an electric circuit therein; a heat sink provided on the outer surface of the housing and thermally connected to the electric circuit. Power conversion device.

2. a cover for covering the heat sink; The heat sink has a fixing surface to which the cover is fixed. The power conversion device according to claim 1 .

3. The heat sink is a plate-shaped base provided on the outer surface; a plurality of fins projecting from the base and extending along a first direction parallel to the outer surface; The plurality of fins are one or more first fins each having the fixing surface at a tip thereof; a plurality of second fins having a lower protruding height than the one or more first fins; The power conversion device according to claim 2 .

4. The difference in height between the protruding height of the one or more first fins and the protruding height of the plurality of second fins is 0.2 mm or more and 3 mm or less. The power conversion device according to claim 3 .

5. The thickness of the one or more first fins is greater than the thickness of the plurality of second fins. The power conversion device according to claim 3 .

6. the housing has an opening that opens to the outer surface and communicates between the inside and the outside of the housing, The base is provided to close the opening. The power conversion device according to claim 3 .

7. a fixing member attached to the heat sink and abutting and fixing the cover to the fixing surface; The power conversion device according to any one of claims 2 to 6.

8. The cover has a cover body made of a conductive metal and a coating layer covering a surface of the cover body, The surface of the cover has a painted surface covered with the coating film layer and an exposed surface on which the cover body is exposed, the fixing member has a clamping portion that clamps the cover between itself and the fixing surface, The exposed surface is provided on a portion of the surface of the cover with which the clamping portion abuts. The power conversion device according to claim 7.

9. Among the plurality of fins arranged along a second direction that intersects the first direction and is parallel to the outer surface, a pair of fins located at both ends in the second direction are the first fins, The cover has a main body plate that connects between the pair of fixing surfaces of the pair of first fins. The power conversion device according to claim 3 .

10. the main body plate has a pair of first sides extending along the first direction, The cover further includes a pair of side plates extending from the edges of the pair of first sides and facing the side surfaces of the pair of first fins. The power conversion device according to claim 9.

11. a power conversion device; a charging cable connected to a vehicle and supplying the power output by the power conversion device to the vehicle; The power conversion device is a housing that houses an electric circuit therein; a heat sink provided on the outer surface of the housing and thermally connected to the electric circuit. Vehicle charging equipment.

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