Inverter device, motor unit, and vehicle

Abstract

The present invention provides an inverter device, a motor unit, and a vehicle. The inverter device includes: a capacitor module having a capacitor element and a capacitor housing that houses the capacitor element; and an outer casing having a housing space for housing the capacitor module. A flow path through which a refrigerant flows and a first opening that opens a part of the flow path to the housing space side are provided in a wall portion constituting the outer casing. The capacitor housing has a metal heat transfer portion that covers the first opening. The refrigerant flows between an inner wall surface of the first opening and the heat transfer portion.

Description

Technical Field

[0001] The present invention relates to an inverter device, a motor unit, and a vehicle. Background Art

[0002] As a control device for a motor of an electric vehicle or a hybrid vehicle, an inverter device has been developed. Since the inverter device includes heat-generating components, it is required to cool them appropriately. For example, a power conversion device provided with a cooler through which cooling water flows is disclosed in Patent Document 1. This cooler directly cools a power semiconductor module and cools a capacitor module via a heat transfer plate.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-108524

[0004] In an existing inverter device, a refrigerant does not directly cool a capacitor. Compared with a method of cooling a capacitor module via other components, it is necessary to improve the cooling efficiency. Summary of the Invention

[0005] In view of the above circumstances, one object of the present invention is to provide an inverter device, a motor unit, and a vehicle that can effectively cool a capacitor as compared with cooling via other components.

[0006] One aspect of the present invention is an inverter device including: a capacitor module having a capacitor element and a capacitor housing that houses the capacitor element; and an outer housing having a housing space that houses the capacitor module. A flow path through which a refrigerant flows and a first opening that opens a part of the flow path on the side of the housing space are provided in a wall portion constituting the outer housing. The capacitor housing has a metal heat transfer portion that covers the first opening. The refrigerant flows between an inner wall surface of the first opening and the heat transfer portion.

[0007] According to one aspect of the present invention, an inverter device, a motor, and a vehicle that can effectively cool a capacitor as compared with cooling via other components are provided. Brief Description of the Drawings

[0008] Figure 1 is a perspective view of a motor unit equipped with an inverter device according to one embodiment.

[0009] Figure 2 is a cross-sectional view of an inverter device according to one embodiment.

[0010] Figure 3 is Figure 2 a partially enlarged schematic view of

[0011] Figure 4 is a perspective view showing an inverter device according to one embodiment.

[0012] Figure 5 It is a top view of an inverter device according to an embodiment.

[0013] Reference Numeral Explanation

[0014] 1: Inverter device; 3: Motor unit; 6: Heat transfer part; 6f: First opposing surface; 6s: Second opposing surface; 7: Bus bar; 8: Power supply terminal; 10: Housing; 11a: Bottom wall; 11b: Side wall; 12: Cover part (wall part); 13: First opening; 13a: First bottom wall surface (bottom wall surface); 13b: First side wall surface (side wall surface); 14: Second opening; 19: Flow path; 30: Capacitor module; 31: First capacitor element (capacitor element); 32: Second capacitor element; 33: Capacitor housing; 38: Terminal block; 40: Power module; 41: Switch element; 42: Element pedestal component; 50: Main substrate; 52: Microcomputer; 53: Gate driver integrated circuit; 60: Substrate; 65: External connector; 68: Inter-substrate connector; R: Refrigerant; S: Storage space. Detailed Embodiment

[0015] Hereinafter, the inverter device 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following drawings, in order to facilitate understanding of each structure, the actual structure may sometimes be different from the scale, quantity, etc. in each structure.

[0016] In the following description, the direction of gravity is defined based on the positional relationship when the inverter device 1 is mounted on a vehicle located on a horizontal road surface. In addition, the posture of the inverter device 1 in this specification is an example and does not limit the actual mounting posture of the inverter device 1.

[0017] In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction represents the vertical direction (i.e., the up and down direction), the +Z direction is the upper side (the opposite side of the direction of gravity), and the -Z direction is the lower side (the direction of gravity). In addition, the X-axis direction is a direction perpendicular to the Z-axis direction and represents the front and rear direction of the vehicle on which the inverter device 1 is mounted. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction and represents the width direction (left and right direction) of the vehicle.

[0018] (Motor Unit)

[0019] Figure 1 It is a perspective view of the motor unit 3 on which the inverter device 1 is mounted.

[0020] The motor unit 3 includes an inverter device 1, a motor 2, a motor housing 4, and a reduction device 5.

[0021] The motor unit 3 of the present embodiment is mounted on a vehicle using a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV), and is used as their power source.

[0022] The motor housing 4 houses the motor 2 and the reduction gear 5 inside. The inverter device 1 is fixed to the outer side surface of the motor housing 4. The motor 2 is supplied with alternating current from the inverter device 1. The motor 2 is controlled by the inverter device 1. The reduction gear 5 is connected to the rotor of the motor 2. The reduction gear 5 decelerates the rotation of the motor 2 and outputs it.

[0023] (Inverter device)

[0024] Figure 2 is a cross-sectional view of the inverter device 1. Figure 3 is Figure 2 a partial enlarged view of

[0025] In addition, in order to clearly show the flow of the refrigerant R, Figure 3 is schematically illustrated with a different dimensional ratio from Figure 2 that of

[0026] The inverter device 1 includes a housing 10, a capacitor module 30, a power module 40, and a main substrate 50. And, as described in the following section, Figure 4 as shown, the inverter device 1 has a bus bar 7 and a sub-substrate 60.

[0027] (Housing)

[0028] As Figure 2 shown, the housing 10 has a housing body 11 and a cover portion (wall portion) 12. The housing body 11 and the cover portion 12 are made of, for example, aluminum alloy and are formed by casting such as die casting. The housing body 11 may also be a part of the motor housing 4.

[0029] The housing body 11 is open at the upper side. The opening at the upper side of the housing body 11 is covered by the cover portion 12. The housing 10 has a storage space S surrounded by the housing body 11 and the cover portion 12. The capacitor module 30, the power module 40, the bus bar 7, the main substrate 50, and the sub-substrate 60 are stored in the storage space S and fixed to the cover portion 12 inside the storage space S.

[0030] The housing body 11 has a bottom wall 11a extending along a horizontal plane and side walls 11b protruding upward from the outer edge of the bottom wall 11a. The bottom wall 11a is located below the storage space S. The side walls 11b surround the storage space S in the horizontal direction. The cover portion 12 is fixed to the upper end surface of the side walls 11b.

[0031] The cover portion 12 extends along a plane perpendicular to the vertical direction. A flow path 19 for the refrigerant to flow through is provided in the cover portion 12. The refrigerant flowing in the flow path 19 cools the power module 40 and the capacitor module 30 disposed in the accommodation space S. The flow path 19 extends along a plane perpendicular to the vertical direction inside the cover portion 12.

[0032] The flow path 19 has an upstream end portion 19a located on the upstream side of the refrigerant flowing in the flow path 19 and a downstream end portion 19b located on the downstream side. A pipe (not shown) connected to a cooler (not shown) for cooling the refrigerant is connected to the upstream end portion 19a. The downstream end portion 19b is connected to a sub-flow path 11c provided in the side wall 11b of the housing main body 11. The sub-flow path 11c is connected to an oil cooler (not shown) located below the inverter device 1. The refrigerant exchanges heat with the oil circulating in the motor housing 4 in the oil cooler.

[0033] In the present embodiment, the refrigerant is cooled by a cooler (not shown), then cools the power module 40 and the capacitor module 30 through the cover portion 12, and further cools the oil through the oil cooler. After the refrigerant passes through the above path, it returns to the cooler again and circulates in the same path.

[0034] The cover portion 12 has an upper surface 12a facing upward and a lower surface 12b facing downward. The lower surface 12b faces the accommodation space S. A first opening 13 and a second opening 14 are provided in the lower surface 12b. That is, a first opening 13 and a second opening 14 are provided in the cover portion 12. The first opening 13 and the second opening 14 open downward respectively. The first opening 13 and the second opening 14 are arranged side by side in the lateral direction along the plane direction of the cover portion 12. The first opening 13 and the second opening 14 are recessed in a concave shape along the thickness direction of the cover portion 12 (more specifically, upward). At least a part of the capacitor module 30 is received in the first opening 13. On the other hand, at least a part of the power module 40 is received in the second opening 14.

[0035] The first opening 13 and the second opening 14 are arranged in the path of the flow path 19. The first opening 13 and the second opening 14 respectively open a part of the flow path 19 to the accommodation space S side. The first opening 13 is arranged at a position downstream of the second opening 14 with respect to the flow path 19. The flow path 19 has a first region 19f connecting the upstream end portion 19a and the second opening 14, a second region 19s connecting the second opening 14 and the first opening 13, and a third region 19t connecting the first opening 13 and the downstream end portion 19b. The refrigerant flowing into the flow path 19 from the upstream end portion 19a passes through in the order of the first region 19f, the second opening 14, the second region 19s, the first opening 13, and the third region 19t.

[0036] The inner wall surface of the first opening 13 includes a first bottom wall surface (bottom wall surface) 13a facing the thickness direction of the lid portion 12 (downward in this embodiment) and a first side wall surface (side wall surface) 13b extending in the thickness direction from the first bottom wall surface 13a. The second region 19s and the third region 19t of the flow path 19 open on the first side wall surface 13b. Here, the opening to the second region 19s is referred to as the first inlet 19p, and the opening to the third region 19t is referred to as the first outlet 19q. The refrigerant flows into the first opening 13 from the first inlet 19p and flows out from the first outlet 19q.

[0037] As Figure 3 shown, a first pedestal portion 12f surrounding the periphery of the first opening 13 is provided on the lower surface 12b of the lid portion 12. The first pedestal portion 12f projects downward. The first pedestal portion 12f has a first pedestal surface 12fa facing downward. A first groove 12fg surrounding the periphery of the first opening 13 is provided on the first pedestal surface 12fa. The first groove 12fg opens downward. A first sealing member 12fh is disposed in the first groove 12fg.

[0038] As Figure 2 shown, the inner wall surface of the second opening 14 includes a second bottom wall surface 14a facing the thickness direction of the lid portion 12 (downward in this embodiment) and a second side wall surface 14b extending in the thickness direction from the second bottom wall surface 14a. The first region 19f and the second region 19s of the flow path 19 open on the second bottom wall surface 14a. Here, the opening to the first region 19f is referred to as the second inlet 19r, and the opening to the second region 19s is referred to as the second outlet 19u. The refrigerant flows into the second opening 14 from the second inlet 19r and flows out from the second outlet 19u.

[0039] A second pedestal portion 12s surrounding the periphery of the second opening 14 is provided on the lower surface 12b of the lid portion 12. The second pedestal portions 12s project downward respectively. The second pedestal portion 12s has a second pedestal surface 12sa facing downward. A second groove 12sg surrounding the periphery of the second opening 14 is provided on the second pedestal surface 12sa. The second groove 12sg opens downward. A second sealing member 12sh is disposed in the second groove 12sg.

[0040] (Capacitor module)

[0041] Figure 4 is a perspective view showing the lid portion 12 and the respective parts of the inverter device 1 fixed to the lid portion 12. In addition, Figure 5 is a top view of a part of the inverter device 1 as viewed from below.

[0042] In addition, in Figure 4 andFigure 5 In the figure, a wiring portion for electrically connecting the capacitor module 30 and the power module 40 is omitted, etc.

[0043] As Figure 5 shown, the capacitor module 30 includes a first capacitor element (capacitor element) 31, a second capacitor element 32, and a capacitor housing 33. The capacitor housing 33 houses the first capacitor element 31 and the second capacitor element 32. Figure 5 The structure of the capacitor module 30 shown is an example and is not limited thereto. As long as at least one capacitor element is housed in the capacitor housing 33 of the capacitor module 30, it is also possible not to house a plurality of or various capacitor elements in the capacitor housing 33.

[0044] In the following description, without distinguishing between the first capacitor element 31 and the second capacitor element 32 from each other, they are simply referred to as capacitor elements 31 and 32.

[0045] The first capacitor element 31 is an X capacitor. The first capacitor element 31 smoothes the power supply provided to the power module 40. A large current is supplied to the first capacitor element 31. Therefore, the calorific value of the first capacitor element 31 is larger than that of the second capacitor element 32. The first capacitor element 31 is cooled by a refrigerant. In the present embodiment, four first capacitor elements 31 are provided in the inverter device 1.

[0046] The second capacitor element 32 is a capacitor with a calorific value smaller than that of the first capacitor element 31. The second capacitor element 32 is, for example, a Y capacitor. That is, the second capacitor element 32 is a capacitor for removing the switching noise of the power module 40. In addition, the second capacitor element 32 may also be an X capacitor with a capacitance smaller than that of the first capacitor element 31.

[0047] The capacitor housing 33 is fixed to the lower surface 12b of the cover portion 12 of the housing 10. The capacitor housing 33 has a housing main body 34 and a heat transfer portion 6 disposed on the upper surface side of the housing main body 34 (see Figure 3 ). The housing main body is made of an insulating resin material.

[0048] As Figure 5 shown, the housing main body 34 has an element holding portion 35 for holding the capacitor elements 31 and 32 and a terminal block 38 for holding the bus bar 7.

[0049] The bus bar 7 connects the power supply terminal 8 and the capacitor module 30. A part of the bus bar 7 passes through a region surrounded by a magnet 7c for electromagnetic compatibility (EMC: Electric Magnetic Compatibity) between the power supply terminal 8 and the capacitor module 30.

[0050] The power supply terminal 8 extends from a battery (not shown) mounted on the vehicle. The power supply terminal 8 is connected to the bus bar 7 from the side of the inverter device 1. The inverter device 1 is supplied with a high-voltage direct current from the battery via the power supply terminal 8.

[0051] According to the present embodiment, the capacitor housing 33 has a resin terminal block 38 that holds the bus bar 7. Since a power supply terminal extending from the outside is connected to the bus bar 7, a high-voltage current also flows through the bus bar 7. By holding the bus bar 7 with the resin terminal block 38, it is possible to easily perform the connection process with the power supply terminal 8 while suppressing a short circuit between the bus bar 7 and other components. In addition, by providing the terminal block 38 on the capacitor housing 33, it is possible to reduce the number of components compared to the case of separately preparing other components.

[0052] As Figure 2 shown, the component holding portion 35 of the housing main body 34 has a main board portion 35a extending along a plane perpendicular to the vertical direction, a concave portion 35b recessed upward with respect to the main board portion 35a, and a peripheral wall portion 35c protruding downward from the outer edge of the flat plate portion.

[0053] The peripheral wall portion 35c surrounds wiring components (not shown) of the capacitor module 30 from the outside. The peripheral wall portion 35c ensures the creepage distance between each part of the capacitor module 30 and the inner wall surface of the housing 10, thereby ensuring the insulation between the capacitor module 30 and the housing 10.

[0054] The concave portion 35b has a substantially constant plate thickness. Therefore, the concave portion 35b protrudes convexly upward. The capacitor elements 31 and 32 are housed in the concave portion 35b. That is, a capacitor element chamber C for arranging the capacitor elements 31 and 32 is provided inside the concave portion 35b.

[0055] The concave portion 35b has a bottom plate portion 36a extending along a plane perpendicular to the vertical direction and side plate portions 36b extending downward from the outer edge of the bottom plate portion 36a. The bottom plate portion 36a faces the capacitor elements 31 and 32 in the vertical direction. The side plate portions 36b surround the periphery of the capacitor elements 31 and 32 from the outside.

[0056] The heat transfer portion 6 is made of a metal material having high heat conductivity. As the material constituting the heat transfer portion 6, for example, aluminum alloy, copper alloy, etc. are exemplified.

[0057] The heat transfer part 6 is fixed to the component holding part 35 of the housing main body 34. As a fixing method for the heat transfer part 6 and the housing main body 34, caulking such as ultrasonic caulking or thermocompression bonding is exemplified. In addition, the heat transfer part 6 can also be fixed to the housing main body 34 by insert molding in which it is buried in a part of the housing main body 34 when the housing main body 34 is molded. When the heat transfer part 6 and the housing main body 34 are fixed by insert molding, the close contact between the heat transfer part 6 and the housing main body 34 can be improved, so it is easy to improve the heat transfer performance with each other.

[0058] As Figure 3 shown, the heat transfer part 6 is plate-shaped. The heat transfer part 6 is formed, for example, by a stamping process. The heat transfer part 6 covers the main board part 35a and the concave part 35b of the component holding part 35 from above.

[0059] The heat transfer part 6 has a flat plate part 6c that overlaps with the main board part 35a of the component holding part 35 and an insertion part 6d that overlaps with the concave part 35b of the component holding part 35.

[0060] When viewed from the thickness direction of the cover part 12, the flat plate part 6c is arranged around the first opening part 13. The upper surface of the flat plate part 6c faces the first pedestal surface 12fa in the vertical direction. A first sealing member 12fh is clamped between the upper surface of the flat plate part 6c and the bottom surface of the first groove 12fg provided on the first pedestal surface 12fa. Thus, when viewed from the thickness direction of the cover part 12, the area arranged inside the first sealing member 12fh is sealed, suppressing the leakage of the refrigerant R.

[0061] The insertion part 6d protrudes upward with respect to the flat plate part 6c. The insertion part 6d is inserted into the first opening part 13 of the cover part 12. Thus, the heat transfer part 6 covers the first opening part 13.

[0062] The insertion part 6d has a bottom part 6a that covers the upper surface of the bottom plate part 36a of the component holding part 35 and a side part 6b that is arranged outside the side plate part 36b. The bottom part 6a is in the shape of a flat plate extending along a plane perpendicular to the vertical direction. The side part 6b extends downward from the outer edge of the bottom part 6a and is connected to the flat plate part 6c at the lower end part. The side part 6b surrounds the side plate part 36b of the concave part 35b from the outside.

[0063] The bottom part 6a faces the first bottom wall surface 13a of the first opening part 13 with a gap therebetween. Similarly, the side part 6b faces the first side wall surface 13b of the first opening part 13 with a gap therebetween. Here, the upper surface of the bottom part 6a is called the first opposed surface 6f, and the outer peripheral surface of the side part 6b is called the second opposed surface 6s. That is, the heat transfer part 6 has the first opposed surface 6f that faces the first bottom wall surface 13a and the second opposed surface 6s that faces the first side wall surface 13b.

[0064] A first inlet 19p for allowing the refrigerant R to flow into the first opening 13 is provided on the first side wall surface 13b of the first opening 13. The refrigerant R flowing into the first opening 13 flows between the first bottom wall surface 13a of the first opening 13 and the first opposing surface 6f of the heat transfer portion 6. In addition, the refrigerant R flowing into the first opening 13 flows between the first side wall surface 13b of the first opening 13 and the second opposing surface 6s of the heat transfer portion 6. The refrigerant R in the first opening 13 flows out from the first outlet 19q provided on the first side wall surface 13b of the first opening 13.

[0065] According to the present embodiment, a part of the capacitor housing 33 covers the first opening 13 of the cover portion 12, and the refrigerant R flows between the inner wall surface of the first opening 13 and the heat transfer portion 6. Therefore, the refrigerant R directly contacts the capacitor module 30 for cooling. In other words, a part of the capacitor housing 33 serves both to cover the opening 13 and to cool the capacitor module 30. As a result, the capacitor module 30 can be cooled quickly and effectively using the refrigerant R.

[0066] According to the present embodiment, the refrigerant R contacts the heat transfer portion 6 of the capacitor housing 33. Since the heat transfer portion 6 is made of a metal with high heat transfer performance, the temperature can easily drop immediately by cooling through contact with the refrigerant R. In addition, since the heat capacity is large, the cooling effect can easily continue. Therefore, the capacitor housing 33 of the present embodiment can immediately and continuously cool the capacitor elements 31 and 32 housed therein.

[0067] In the present embodiment, the metal heat transfer portion 6 contacts the resin housing main body 34. In addition, the housing main body 34 contacts the capacitor elements 31 and 32 to hold the capacitor elements 31 and 32. Therefore, the capacitor housing 33 can effectively cool the capacitor elements 31 and 32 through the heat transfer portion 6 while ensuring insulation between the heat transfer portion 6 and the capacitor elements 31 and 32.

[0068] In the present embodiment, the heat transfer portion 6 has a bottom portion 6a and a side portion 6b that surround the capacitor element chamber C of the capacitor housing 33 from above and the outer peripheral side. Therefore, the heat transfer portion 6 cooled by the refrigerant R can cool the inside of the capacitor element chamber C from above and the outer peripheral side. According to the heat transfer portion 6 of the present embodiment, the cooling efficiency of the capacitor elements 31 and 32 arranged in the capacitor element chamber C can be improved.

[0069] According to the present embodiment, at least a part of the capacitor module 30 is housed in the concave first opening 13. Generally, there is a tendency that the larger the component size of the capacitor elements 31 and 32 housed in the capacitor module 30, the greater the vertical length of the capacitor module 30 and the inverter device 1. However, in the present embodiment, by housing a part of the capacitor module 30 in the concave first opening 13, it is possible to form a shape that is buried in the thickness direction of the cover portion 12. Therefore, the inverter device 1 can be miniaturized in the vertical direction.

[0070] In the present embodiment, the refrigerant R flows between the first bottom wall surface 13a and the first opposing surface 6f and between the first side wall surface 13b and the second opposing surface 6s. That is, the refrigerant R cools not only one surface of the capacitor module 30 but also a plurality of surfaces in a wide range. Thereby, the refrigerant R can cool the capacitor module 30 quickly and effectively. Further, in the present embodiment, the flow path of the refrigerant R in the first opening 13 is provided so as to surround the capacitor element chamber C from the lower side and the outer peripheral side. That is, the refrigerant R cools the capacitor elements 31 and 32 by surrounding them from multiple directions. Therefore, the cooling efficiency of the refrigerant R for the capacitor elements 31 and 32 can be improved.

[0071] In Figure 5 FIG. Figure 5 shows schematically the flow of the refrigerant R that flows into the first opening 13 at the first inlet 19p and flows out of the first opening 13 at the first outlet 19q. As

[0072] (Power module)

[0073] As Figure 2 shown, the power module 40 has a switching element 41 and an element pedestal member 42. The element pedestal member 42 serves as a pedestal for fixing the switching element 41.

[0074] The power module 40 is arranged along the cover portion 12 of the housing 10. The power module 40 and the capacitor module 30 are arranged side by side in the surface direction of the cover portion 12. That is, the power module 40 and the capacitor module 30 are arranged adjacent to each other so as not to overlap when viewed from the thickness direction of the cover portion 12.

[0075] In recent years, the development of an electromechanical integrated motor unit in which an inverter device is integrated has been underway. In such an inverter device, if the size in the height direction becomes large, there is a possibility of pressing the riding space in the vehicle. Therefore, the development of a thinner inverter device is required. According to the method described in this specification, a thinner inverter device is provided.

[0076] According to the present embodiment, since the power module 40 and the capacitor module 30 are arranged side by side in the plane direction of the cover portion 12, the inverter device 1 can be miniaturized in the thickness direction of the cover portion 12.

[0077] The switching element 41 of the present embodiment is an insulated gate bipolar transistor (IGBT: Insulated Gate Bipolar Transistor). The switching element 41 generates more heat than the capacitor elements 31 and 32. The switching element 41 is cooled by a refrigerant.

[0078] The element pedestal member 42 is made of a metal material with high heat conductivity. As the material constituting the element pedestal member 42, for example, aluminum alloy, copper alloy, etc. are exemplified. The element pedestal member 42 functions as an element pedestal member that transfers heat from the switching element 41 to the refrigerant.

[0079] The element pedestal member 42 holds the switching element 41. The element pedestal member 42 has a plate-shaped cover body 42a and a plurality of heat dissipation pins 42c protruding upward from the upper surface of the cover body 42a. The lower surface of the cover body 42a is in contact with the switching element 41 and is fixed.

[0080] The upper surface of the cover body 42a covers the second opening 14. In addition, the upper surface of the cover body 42a faces the second pedestal surface 12sa in the vertical direction. A second sealing member 12sh is sandwiched between the upper surface of the cover body 42a and the bottom surface of the second groove 12sg provided on the second pedestal surface 12sa. Thus, when viewed from the thickness direction of the cover portion 12, the area disposed inside the second sealing member 12sh is sealed, suppressing the leakage of the refrigerant.

[0081] A plurality of heat dissipation pins 42c are arranged inside the second opening 14. A second inlet 19r for the refrigerant to flow into the second opening 14 is provided on the second bottom wall surface 14a of the second opening 14. The refrigerant flowing into the second opening 14 flows between the second bottom wall surface 14a of the second opening 14 and the upper surface of the cover body 42a and in the gaps between the plurality of heat dissipation pins 42c. The refrigerant in the second opening 14 flows out from a second outlet 19u provided on the second bottom wall surface 14a of the second opening 14.

[0082] According to the present embodiment, the refrigerant flows between the inner wall surface of the second opening 14 and the element pedestal member 42. That is, the refrigerant directly contacts the power module 40 for cooling. And the element pedestal member 42 cools the switching element. Therefore, the refrigerant cools the power module 40 quickly and effectively.

[0083] According to the present embodiment, the element pedestal member 42 has a plurality of heat dissipation pins 42c disposed in the second opening 14. Further, the refrigerant passes between the plurality of heat dissipation pins 42c. Therefore, a relatively large contact area between the element pedestal member 42 and the refrigerant can be ensured, and thus the element pedestal member 42 can be effectively cooled by the refrigerant.

[0084] Further, in the present embodiment, the calorific value of the capacitor module 30 is smaller than that of the power module 40. Therefore, the heat transfer portion 6 of the capacitor module 30 can sufficiently ensure the contact area with the refrigerant with respect to the calorific value, and it is not necessarily required to have heat dissipation pins like the power module 40. However, when it is difficult to sufficiently ensure the contact area between the heat transfer portion 6 and the refrigerant with respect to the calorific values of the capacitor elements 31 and 32, heat dissipation pins may be provided on the heat transfer portion 6.

[0085] In the present embodiment, the second opening 14 is disposed upstream of the first opening 13 in the flow path 19. Therefore, the refrigerant cooled in a cooler (not shown) cools the power module 40 in the second opening 14 and then cools the capacitor module 30 in the first opening 13. According to the present embodiment, the power module 40 with a large calorific value can be effectively cooled by the refrigerant at a low temperature.

[0086] (Main substrate)

[0087] As Figure 4 shown, the main substrate 50 is disposed along the lid portion 12. When viewed from the thickness direction of the lid portion 12, the main substrate 50 overlaps with the capacitor module 30 and the power module 40.

[0088] The main substrate 50 has a substrate body 51, a microcomputer 52 mounted on the substrate body 51, and a gate driver integrated circuit 53.

[0089] The substrate body 51 extends along a plane perpendicular to the vertical direction. The microcomputer 52 and the gate driver integrated circuit 53 are mounted on the lower surface of the substrate body 51. On the lower surface of the substrate body 51, a region where a plurality of microcomputers 52 are mounted and a region where a plurality of gate driver integrated circuits 53 are mounted are adjacently provided.

[0090] The microcomputer 52 is connected to the motor 2 to control the motor 2. The gate driver integrated circuit 53 controls the power module 40. According to the present embodiment, the microcomputer 52 and the gate driver integrated circuit 53 are mounted on one main substrate 50.

[0091] As an existing configuration, a configuration is known in which a control board for mounting a microcomputer and a power board for mounting a gate driver integrated circuit are separately prepared and stacked. According to the present embodiment, by integrating the control board and the power board on one board (main board 50), it is possible to reduce the thickness of the inverter device 1 without stacking the boards. In addition, compared with the existing configuration, there is no need for wiring to connect the control board and the power board, and the number of components can be reduced.

[0092] (Sub-board)

[0093] The sub-board 60 is arranged along the cover portion 12. When viewed from the thickness direction of the cover portion 12, the sub-board 60 extends in one direction (X-axis direction) along the outer edge of the cover portion 12.

[0094] The sub-board 60 is arranged on the side of the capacitor module 30 and the power module 40. The sub-board 60 is arranged horizontally with respect to the capacitor module 30 and the power module 40 along the plane direction of the cover portion 12. On the other hand, when viewed from the thickness direction of the cover portion 12, a part of the sub-board 60 overlaps with the main board 50. That is, the sub-board 60 is arranged along the main board 50.

[0095] The sub-board 60 has a sub-board main body 61 and a filter element 62. The sub-board main body 61 extends along a plane perpendicular to the vertical direction. The filter element 62 is mounted on the lower surface of the sub-board main body 61.

[0096] A male connector 68a is connected to the lower surface of the sub-board main body 61. Similarly, a female connector 68b is connected to the upper surface of the board main body 51 of the main board 50. The male connector 68a and the female connector 68b are connected to overlap each other in the vertical direction. The male connector 68a and the female connector 68b constitute an inter-board connector 68 for connecting the sub-board 60 and the main board 50. That is, the inverter device 1 has an inter-board connector 68 that connects the main board 50 and the sub-board 60 at a portion where the sub-board 60 and the main board 50 overlap in the thickness direction.

[0097] According to the present embodiment, the main board 50 and the sub-board 60 are connected by the inter-board connector 68. Therefore, there is no need to use a wire harness to connect the main board 50 and the sub-board 60, and the assembly process required for handling the wire harness can be simplified.

[0098] Two external connectors 65 and 66 are connected to the upper surface of the sub-board main body 61. That is, the inverter device 1 has external connectors 65 and 66. Terminals (not shown) extending from the outside are respectively connected to the external connectors 65 and 66. The terminals connected to the external connectors 65 and 66 are, for example, signal terminals for transmitting command signals from the vehicle side.

[0099] The filter element 62 suppresses the switching noise caused by the on / off switching of the switching element 41 from being transmitted to the wiring harness outside the inverter device 1 via the external connectors 65 and 66. Generally, the noise contained in the external signal is easily affected by the magnetic fields of other components. Therefore, the structure of the filter element 62 is adjusted after the configurations and structures of other components are determined. According to the present embodiment, the filter element 62 is provided on the sub-board 60. Therefore, after the structures of other components of the inverter device 1 and each part of the motor unit 3 are determined, various replacements of the sub-board 60 can be performed to adjust the noise filter. As a result, the adjustment of the filter element 62 becomes easy, and a more reliable inverter device 1 can be constructed.

[0100] The inverter device 1 of the present embodiment has, in addition to the main board 50, a sub-board 60 for connecting the external connectors 65 and 66. Therefore, by arranging the sub-board 60 in accordance with the arrangements of the external connectors 65 and 66, the external connectors 65 and 66 can be directly connected to the sub-board 60. That is, according to the present embodiment, there is no need to connect a wiring harness or the like for connecting to the board to the external connectors 65 and 66, so that the number of components can be reduced.

[0101] The inverter device 1 of the present embodiment is mounted on the motor unit 3. The motor unit 3 is mounted on a vehicle. As described above, the inverter device 1 of the present embodiment can effectively cool the capacitor. Therefore, the tolerance to high currents used in the motor unit 3 or the vehicle is improved. Also, since the inverter device 1 of the present embodiment can be miniaturized in the vertical direction, the motor unit 3 can also be miniaturized in the vertical direction. As a result, the space for arranging components other than the motor unit 3 in the vehicle is also expanded.

[0102] The embodiments of the present invention have been described above. However, each structure and their combinations in the embodiments are merely examples, and additional, omission, substitution, and other changes in the structure can be made without departing from the gist of the present invention. In addition, the present invention is not limited to the embodiments.

[0103] For example, in the above embodiment, the case where the first opening 13, the second opening 14, and the flow path 19 are provided in the cover portion 12 has been described. However, the first opening 13, the second opening 14, and the flow path 19 may also be provided in other wall portions (the bottom wall 11a, the side wall 11b) of the housing 10.

Claims

1. An inverter device, comprising: A capacitor module having a capacitor element and a capacitor housing for receiving the capacitor element; and a housing having a storage space for storing the capacitor module, a flow path through which a refrigerant flows is provided in a wall portion constituting the housing; and a first opening that opens a part of the flow path on the side of the storage space, the capacitor housing has a metal heat transfer portion covering the first opening, the housing includes a first inlet that opens to the first opening at a gap defined between the wall portion and the heat transfer portion, the refrigerant flows between the inner wall surface of the first opening and the heat transfer portion.

2. The inverter device according to claim 1, wherein the first opening is recessed in the thickness direction of the wall portion and houses at least a part of the capacitor module, the inner wall surface of the first opening includes: a bottom wall surface facing the thickness direction of the wall portion; and side wall surfaces extending in the thickness direction from the bottom wall surface, the heat transfer portion has: a first opposing surface opposing the bottom wall surface; and a second opposing surface opposing the side wall surfaces, the refrigerant flows between the bottom wall surface and the first opposing surface and between the side wall surfaces and the second opposing surface.

3. The inverter device according to claim 1 or 2, wherein the inverter device has a power module, the capacitor module and the power module are arranged side by side in the plane direction of the wall portion.

4. The inverter device according to claim 3, wherein a second opening that opens a part of the flow path on the side of the storage space is provided in the wall portion, the power module has: a switching element; and a metal element pedestal member that holds the switching element and covers the second opening, the refrigerant flows between the inner wall surface of the second opening and the element pedestal member.

5. The inverter device according to claim 1 or 2, wherein the inverter device has a main substrate on which a microcomputer and a gate driver integrated circuit are mounted, the main substrate is arranged along the wall portion.

6. The inverter device according to claim 5, wherein the inverter device has: an external connector connected to a terminal extending from the outside; a sub-substrate connected to the external connector and arranged along the main substrate; and an inter-substrate connector that connects the sub-substrate and the main substrate at a portion where the sub-substrate and the main substrate overlap in the plate thickness direction.

7. The inverter device according to claim 1 or 2, wherein the inverter device has a bus bar connected to a power supply terminal extending from the outside, the capacitor housing has a resin terminal block that supports the bus bar.

8. A motor unit, wherein the motor unit has the inverter device according to any one of claims 1 to 7.

9. A vehicle, wherein the vehicle has the motor unit according to claim 8.

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