Cooling structure

Abstract

To miniaturize a cooling structure including a flow passage of a working fluid for cooling.SOLUTION: A cooling structure according to the present disclosure includes a housing of a power conversion device, a flow path, and a heat transport member. A plurality of electronic components to be cooled are disposed inside the housing. The flow path is disposed around the housing outside the housing, and the inside of the flow path through which the working fluid flows is spatially isolated from the inside of the housing. The heat transport member is disposed from an inside of the housing to an inside of the flow path. The heat transport member includes a high-temperature portion and a low-temperature portion. The high-temperature portion is thermally connected to each of the plurality of electronic components inside the housing. The low-temperature portion is thermally connected to the working fluid in a flow path outside the housing. The heat transport member forms a heat transport path that transports heat from each of the plurality of electronic components to the working fluid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cooling structure. [Background technology]

[0002] In recent years, power conversion devices (power supplies) such as on-board chargers and DC-DC converters installed in electric vehicles (EVs) have been experiencing problems with heat dissipation due to increased heat loss from components mounted on boards as semiconductors become more powerful. In addition, with the increasing diversification of EVs, there is a demand for miniaturization of on-board power supplies in anticipation of improved mountability, and it has become common for forced liquid cooling fluid channels to be placed inside the housing.

[0003] For example, Patent Document 1 discloses a technology in which a power semiconductor module of a power conversion device is sandwiched between a pair of water channels (heat dissipation members) and heat is dissipated from the power semiconductor module to a pair of heat dissipation members via a pair of conductor members (heat pipes), thereby suppressing local hot spots and reducing the number of members that obstruct the heat dissipation path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-177676 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the placement of the flow paths inside the housing limits the size of the housing, and when the flow paths for the cooling working fluid are formed by die-casting, a sealing structure must be applied to prevent damage to the board-mounted components (heat-generating components) caused by leakage of the working fluid from casting cavities, which creates the problem of an increase in the size of the housing.

[0006] One of the problems to be solved by the present disclosure is to achieve miniaturization of a cooling structure including a flow path for a working fluid for cooling. [Means for solving the problem]

[0007] The cooling structure according to the present disclosure comprises a housing for a power conversion device, a flow path, and a heat transfer member. The housing has a plurality of electronic components to be cooled disposed therein. The flow path is disposed around the housing outside the housing, and the inside of the flow path through which a working fluid flows is spatially isolated from the inside of the housing. The heat transfer member is disposed from the inside of the housing to the inside of the flow path of the flow path. The heat transfer member has a high-temperature portion and a low-temperature portion. The high-temperature portion is thermally connected to each of the plurality of electronic components inside the housing. The low-temperature portion is thermally connected to the working fluid within the flow path outside the housing. The heat transfer member forms a heat transfer path that transfers heat from each of the plurality of electronic components to the working fluid. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to achieve miniaturization of a cooling structure including a flow path for a working fluid for cooling. Note that the effects described herein are not necessarily limited to those described herein, and may be any of the effects described in this specification. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view illustrating an example of the configuration of a cooling structure according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing an example of the configuration of the cooling structure of FIG. [Figure 3] FIG. 3 is a cross-sectional view showing an example of the configuration of the cooling structure of FIG. [Figure 4] FIG. 4 is a perspective view showing an example of the configuration of the heat pipe of FIG. [Figure 5] FIG. 5 is a perspective view illustrating another example of the configuration of the cooling structure according to the embodiment. [Figure 6]FIG. 6 is a perspective view showing an example of the configuration of the cooling structure of FIG. [Figure 7] FIG. 7 is a cross-sectional view showing an example of the configuration of the cooling structure of FIG. [Figure 8] FIG. 8 is a perspective view showing an example of the configuration of the heat pipe of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a cooling structure according to the present disclosure, and a power conversion device and a vehicle to which the cooling structure is applied will be described with reference to the drawings.

[0011] In the description of the present disclosure, components having the same or substantially the same functions as those described above with respect to the previously-mentioned drawings may be given the same reference numerals, and descriptions thereof may be omitted as appropriate. Furthermore, even when the same or substantially the same parts are shown, the dimensions and proportions may be different depending on the drawing. Furthermore, for example, in order to ensure the visibility of the drawings, reference numerals may be given to only the main components in the description of each drawing, and reference numerals may not be given to components having the same or substantially the same functions as those described above with respect to the previously-mentioned drawings.

[0012] In the description of this disclosure, expressions such as orthogonal, horizontal, vertical, parallel, identical, coincident, and the same position are not limited to strictly orthogonal, horizontal, vertical, parallel, identical, coincident, and the same position, but also include cases where they can be considered as orthogonal, horizontal, vertical, parallel, identical, coincident, and the same position.

[0013] The cooling structure according to the present disclosure can be applied to various types of power conversion devices. In the embodiments described below, a power supply device (on-board charger) mounted on a vehicle (mobile body) such as an electric vehicle (EV) or a hybrid vehicle will be exemplified as a power conversion device to which the cooling structure is applied. This on-board charger may be, for example, a power conversion device that converts AC power supplied from a single-phase or three-phase AC power source external to the vehicle into DC power and supplies the converted DC power to a load mounted on the vehicle. This load may be, for example, a battery, an inverter, a motor, various electrical components, etc.

[0014] Note that examples of mobile bodies to which the cooling structure according to the present disclosure is applicable include passenger cars, freight vehicles, buses, motorcycles, electric kick scooters, construction machinery, agricultural machinery, and aircraft. Examples of electrical equipment for mobile bodies include navigation systems, audio systems, air conditioners, power windows, defoggers, ECUs (Electronic Control Units), GPS (Global Positioning System) modules, and cameras. The battery for the mobile body may be any battery capable of storing power for driving the travel motor (main motor) and electrical equipment mounted on the mobile body, and any battery, such as a lithium-ion battery, a nickel-metal hydride battery, or an all-solid-state battery, may be used as appropriate.

[0015] The cooling (heat dissipation) target of the cooling structure according to the present disclosure is, for example, a heat-generating electronic component (heat-generating component) mounted on a power conversion device, but is not limited to this. In addition to or instead of the heat-generating component, the cooling target may also be a component that is heated by the heat from the heat-generating component, or a component that forms part of a heat transport path from the heat-generating component.

[0016] The cooling structure according to the present disclosure may be applied to a heat-generating portion (a cooling target) of a moving body other than a charger. The heat-generating portion of the vehicle may be, for example, an on-board device configured with a plurality of electronic components including power semiconductors and / or magnetic components. As an example, the heat-generating portion of the vehicle may be a power conversion device (DC-DC converter) configured with a plurality of electronic components including magnetic components, converting input DC power to DC power of a predetermined voltage value and outputting the converted DC power. A power conversion device including at least magnetic components may be referred to as a coil device. The heat-generating portion of the vehicle may also be, for example, another on-board device such as a battery or electrical equipment.

[0017] The cooling structure disclosed herein is not limited to power conversion devices mounted on mobile bodies, but may also be applied to power conversion devices mounted on other devices on the mobile body or installed outside the mobile body, such as charging devices at charging stations, amusement facilities, and uninterruptible power supplies.

[0018] A power conversion device to which the cooling structure according to the present disclosure is applied is cooled, for example, using a forced liquid cooling system. This cooling system is applied, for example, to a vehicle (mobile body) and is configured to be able to cool heat-generating parts of the vehicle. As an example, in the cooling system, a coolant (working fluid) for forced liquid cooling circulates and transports heat from the power conversion device to the outside of the power conversion device. This coolant may be the same coolant used to cool the battery, motor, engine, etc. in the vehicle (mobile body). Alternatively, the cooling system may share a radiator mounted on the vehicle (mobile body) with another cooling system.

[0019] The cooling system for the power conversion device is, for example, a liquid-cooled system that uses a coolant as a working fluid. However, the cooling system may also be a system that cools the power conversion device using other cooling methods, such as air-cooled systems or phase-change cooling systems. That is, the cooling system for the power conversion device may be a system that uses any refrigerant as a working fluid. Furthermore, the cooling system for the power conversion device may be configured as part of an air conditioning system, for example, and may use the refrigerant circulating through the air conditioning system as the working fluid. In this case, the cooling structure according to the present disclosure may be connected to, for example, the outlet of an evaporator of the air conditioning system and may be supplied with refrigerant from the evaporator. Furthermore, the cooling structure according to the present disclosure may be connected to, for example, the inlet of a compressor of the air conditioning system and may discharge refrigerant that has passed through it and supply it to the compressor.

[0020] (First embodiment) 1 and 2 are perspective views showing an example of the configuration of a cooling structure 1 according to this embodiment. FIG. 1 illustrates an example of the cooling structure 1 viewed from above (+Z side). FIG. 2 illustrates an example of the cooling structure 1 viewed from below (-Z side). FIG. 3 is a cross-sectional view showing an example of the configuration of the cooling structure 1 of FIG. 1. FIG. 3 illustrates an example of the ZX cross section viewed from the +Y side, as indicated by III-III in FIGS. 1 and 2.

[0021] As shown in Figures 1 to 3, the cooling structure 1 according to this embodiment is applied to a power supply device 3. The power supply device 3 is equipped with a plurality of electronic components, including heat-generating components to be cooled (dissipated). Here, the power supply device 3 according to the embodiment is an example of a power conversion device configured with a plurality of electronic components, including power semiconductors and / or magnetic components. This power supply device 3 can be realized as an on-board charger to be installed in a vehicle (mobile object), for example.

[0022] 1 to 3, the power supply device 3 has a housing 30. The housing 30 is a box-shaped member made of a metal material such as die-cast. In other words, the housing 30 is made of a thermally conductive material and may form part of a heat transfer path that transfers heat from an electronic component to be cooled to a working fluid such as a coolant.

[0023] 1 to 3, the upper side (+Z side) of the housing 30 is open, but this is not limitative. For example, a lid-like member (not shown) may be provided on the upper side (+Z side) of the housing 30. This lid-like member is not limited to being provided on the upper side (+Z side) of the housing 30, but may also be provided on any side of the housing 30 on which the flow path 7 is not provided (-X side, +Y side, -Y side, -Z side). Alternatively, part or all of the side of the housing 30 on which the flow path 7 is not provided (-X side, +Y side, -Y side, -Z side) may be open.

[0024] A plurality of board-mounted components 33 mounted on a substrate 31 are provided in the housing interior 30b, which is the internal space of the housing 30. These plurality of board-mounted components 33 are an example of a plurality of electronic components including semiconductors and / or magnetic components. For example, in the example of FIGS. 1 to 3, the board-mounted components 33 arranged in the housing interior 30b of the power supply device 3 include a MOSFET 33a (power semiconductor), a transformer 33b, an electrolytic capacitor 33c, and a choke coil 33d. Note that FIGS. 1 to 3 illustrate a case where the choke coil 33d is potted within the casing.

[0025] Note that some or all of the multiple electronic components of power supply device 3 may be electrically connected via a bus bar or the like, i.e., without via substrate 31. In other words, some or all of the multiple electronic components of power supply device 3 do not have to be configured as board-mounted components. Similarly, substrate 31 is not an essential component of power supply device 3, and may not be provided.

[0026] For example, the power supply device 3 may be provided with a noise filter that suppresses (removes) noise from entering the power supply device 3 from an external AC power supply and from leaking noise from the power supply device 3 to the AC power supply. Furthermore, for example, a power conversion circuit is provided downstream of the noise filter to convert AC power supplied from an external single-phase or three-phase AC power supply via the noise filter into DC power and output the converted DC power to a battery. This power conversion circuit may be provided with a power factor correction (PFC) circuit that rectifies and smooths the AC voltage from the external AC power supply after noise removal by the noise filter to generate a DC voltage. Furthermore, for example, a DC-DC converter is provided downstream of the PFC circuit in the power conversion circuit to convert the DC voltage generated by the PFC circuit back into AC voltage and then rectifies and smooths the converted AC voltage to generate a DC voltage of an arbitrary set voltage.

[0027] For example, each part of the on-board charger, such as the PFC circuit or DC-DC conversion circuit, includes board-mounted components 33 (heat-generating components) such as a MOSFET 33a (power semiconductor) or an electrolytic capacitor 33c. These board-mounted components 33 generate a lot of heat when power conversion is performed on high-current or high-voltage power. Such board-mounted components 33 are an example of a target to be cooled by the cooling structure 1 according to the present disclosure, and are also an example of a heat-generating part of a vehicle.

[0028] For example, various components of an on-board charger, such as a PFC circuit or a DC-DC conversion circuit, include electronic components such as electrolytic capacitor 33c, which have a strong correlation between temperature and lifespan. These electronic components may have an upper limit of their operating temperature set lower than the maximum operating temperature stipulated by their specifications. Such electronic components are also examples of targets to be cooled by the cooling structure 1 according to the present disclosure.

[0029] Furthermore, each component of the on-board charger, such as the noise filter, PFC circuit, and DC-DC conversion circuit, includes magnetic components such as various inductors and reactors, such as the transformer 33b, the transformer-integrated printed circuit board, and the choke coil 33d, as well as assemblies including these. The on-board charger and the coil device equipped with magnetic components such as the noise filter, PFC circuit, and DC-DC conversion circuit (DC-DC converter) generate a lot of heat when converting high-current and high-voltage power. Such coil devices or magnetic components of the coil device are an example of a target to be cooled by the cooling structure 1 according to the present disclosure, and are also an example of a heat-generating part of a vehicle.

[0030] As shown in FIGS. 1 to 3, the cooling structure 1 according to this embodiment further includes a flow path 7. As shown in FIG.

[0031] The flow path 7 is an example of a conduit through which a working fluid (coolant) flows that circulates in a cooling system for forced liquid cooling of the power supply device 3. The cooling system of the power supply device 3 may be air-cooled or another liquid-cooled cooling system, and the flow path 7 may be a conduit through which a gas (working fluid) such as air flows. The flow path 7 is formed, for example, from a metal material such as die-cast, but may also be formed from a non-metallic material such as resin. The flow path 7 is formed, for example, from a hollow conduit. The cross-sectional shape of the conduit forming the flow path 7 is arbitrary, and may be circular, elliptical, or polygonal such as rectangular. In this flow path 7, the coolant is supplied from the inlet portion 7a to the flow path interior 7c. The coolant that has flowed through the flow path interior 7c is discharged to the outside of the flow path 7 from the outlet portion 7b.

[0032] As an example, the flow path 7 is disposed adjacent to the housing 30, for example, outside the housing 30 of the power supply device 3. In other words, the flow path 7 side of the housing 30 and the housing 30 side of the flow path 7 are adjacent to each other and are in physical contact (adjacent) with each other. On the other hand, a flow path interior 7c, which is a space within the flow path of the flow path 7, is spatially isolated from the housing interior 30b of the power supply device 3.

[0033] As an example, the housing interior 30b of the power supply device 3 and the flow path interior 7c are arranged via a partition wall 30a and spatially separated, as shown in Fig. 3. Here, the partition wall 30a spatially separates the housing interior 30b of the power supply device 3 from the flow path interior 7c, and may be common to the housing 30 and the flow path 7, or may be provided separately. For example, the partition wall 30a may be formed by a part of the housing 30 of the power supply device 3, or may be formed by a part of a member that forms the flow path 7, or may be formed by both of these.

[0034] As an example, in the cooling structure 1 according to this embodiment, the flow path 7 does not overlap with the housing 30 of the power supply device 3 in a plan view. Specifically, the flow path 7 does not overlap with the housing 30 when the XY plane is viewed from the +Z side or the -Z side. In other words, the flow path 7 and the housing 30 are located at different positions on the XY plane.

[0035] As shown in FIGS. 1 to 3, the cooling structure 1 according to this embodiment further includes a heat pipe 5. As shown in FIG.

[0036] The heat pipe 5 is an example of a heat transport member that collects heat from the board-mounted components 33 inside the housing 30b of the power supply device 3 and transports it to the space outside the housing 30. The heat pipe 5 is a flat, hollow member made of a metal material such as copper, aluminum, or an alloy thereof, and has a refrigerant sealed inside. Note that the heat pipe 5 according to the embodiment is a thin heat pipe formed, for example, in the shape of a thin, flat plate, but its shape may be determined appropriately depending on the shape and arrangement of the electronic components to be cooled, and part or all of it may be formed in a tubular shape.

[0037] As shown in FIGS. 1 to 3, the heat pipe 5 is arranged from the housing interior 30b of the power supply device 3 to the flow path interior 7c (inside the flow path) of the flow path 7. Specifically, the heat pipe 5 is arranged to penetrate the partition wall 30a, which spatially separates the housing interior 30b of the power supply device 3 from the flow path interior 7c of the flow path 7, at the penetration portion 30c. As an example, the heat pipe 5 is inserted from the housing interior 30b of the power supply device 3 into the penetration portion 30c. In other words, a portion of the heat pipe 5 according to the embodiment protrudes from the housing interior 30b of the power supply device 3 toward the inlet portion 7a of the flow path interior 7c of the flow path 7 to the outside of the housing 30.

[0038] The heat pipe 5 forms a heat transport path that transports heat from each of the multiple board-mounted components 33 (electronic components) to be cooled to the coolant flowing through the flow path interior 7c of the flow path 7. Specifically, the heat pipe 5 is thermally connected to the multiple board-mounted components 33 (electronic components) to be cooled in the housing interior 30b of the power supply device 3. The heat pipe 5 is also thermally connected to the flow path interior 7c of the flow path 7. In other words, the heat pipe 5 is thermally connected to the coolant flowing through the flow path interior 7c of the flow path 7. Therefore, the heat pipe 5 collects heat from the multiple board-mounted components 33 to be cooled in the housing interior 30b of the power supply device 3 and transports it to the outside of the housing 30 of the power supply device 3 (flow path 7).

[0039] Here, in this disclosure, being thermally connected with respect to "A" and "B" means that heat exchange is possible between "A" and "B." Note that, in this disclosure, "thermal connection" is realized, for example, by a heat transfer form such as thermal conduction, but it may be realized by other heat transfer forms in addition to or instead of heat conduction. Also, in this disclosure, "thermal connection" may be realized by a heat transfer path via other elements, such as a heat diffusion sheet or heat diffusion plate, thermally conductive grease, thermally conductive adhesive, fillers such as potting material, other electronic components, etc.

[0040] Fig. 4 is a perspective view showing an example of the configuration of the heat pipe 5 of Fig. 1. As shown in Figs.

[0041] The high-temperature section 51 is a portion of the heat pipe 5 that is arranged inside the housing 30b of the power supply device 3. In other words, the high-temperature section 51 is a part of the heat pipe 5, and is a portion that is located closer to the housing interior 30b of the power supply device 3 than the partition wall 30a when the heat pipe 5 is assembled in the housing 30 of the power supply device 3.

[0042] The high temperature section 51 is thermally connected to each of the plurality of board-mounted components 33 (electronic components) to be cooled inside the housing 30b. That is, the high temperature section 51 diffuses and collects heat from each of the plurality of board-mounted components 33 to be cooled inside the housing 30b.

[0043] The high temperature portion 51 has a main portion extending from the low temperature portion 53. The main portion of the high temperature portion 51 is formed in a flat plate shape. When the main surface of the low temperature portion 53 is arranged along the XY plane, the main portion of the high temperature portion 51 extends along the XY plane to the -X side.

[0044] The high temperature section 51 has a plurality of first high temperature sections 51a, second high temperature sections 51b, third high temperature sections 51c, and fourth high temperature sections 51d.

[0045] Each of the multiple first high temperature portions 51a is formed in a flat plate shape. Each of the multiple first high temperature portions 51a extends from an end of the main portion of the high temperature portion 51 in a direction away from the main surface of the main portion. When the main surface of the main portion of the high temperature portion 51 is arranged along the XY plane, each of the multiple first high temperature portions 51a extends in the Z direction from the +X side end and the - side end of the main portion. As shown in FIGS. 1 to 3, each of the multiple first high temperature portions 51a is thermally connected to the heat dissipation surfaces of the multiple MOSFETs 33a.

[0046] As an example, each of the plurality of first high temperature portions 51a is formed by bending a part of a plurality of convex portions extending from an end of the main portion of the high temperature portion 51 along its main surface to form a bent portion 55. Note that one of the plurality of convex portions can be formed as the low temperature portion 53.

[0047] The second high temperature portion 51b, the third high temperature portion 51c, and the fourth high temperature portion 51d are each provided in the main portion of the high temperature portion 51. That is, the second high temperature portion 51b, the third high temperature portion 51c, and the fourth high temperature portion 51d are each formed in a flat plate shape.

[0048] The second high temperature portion 51b extends in the -X direction from the third high temperature portion 51c. A notch 57 is provided between the second high temperature portion 51b and the third high temperature portion 51c, and the width (length in the Y direction) of each of the second high temperature portion 51b and the third high temperature portion 51c is longer than the width (length in the Y direction) of the connection portion between the second high temperature portion 51b and the third high temperature portion 51c. As shown in FIGS. 1 to 3, the second high temperature portion 51b is thermally connected to the heat dissipation surface of the transformer 33b.

[0049] The third high temperature portion 51c extends in the -X direction from the fourth high temperature portion 51d. A notch 57 is provided between the third high temperature portion 51c and the fourth high temperature portion 51d, and the width (length in the Y direction) of each of the third high temperature portion 51c and the fourth high temperature portion 51d is longer than the width (length in the Y direction) of the connection portion between the third high temperature portion 51c and the fourth high temperature portion 51d. As shown in FIGS. 1 to 3, the third high temperature portion 51c is thermally connected to the heat dissipation surface of the electrolytic capacitor 33c.

[0050] The fourth high temperature portion 51d extends in the −X direction from the low temperature portion 53. As shown in FIGS. 1 to 3, the fourth high temperature portion 51d is thermally connected to the heat dissipation surface of the choke coil 33d.

[0051] The notch 57 is not an essential component and may not be provided.

[0052] The low-temperature section 53 is a portion of the heat pipe 5 that is located outside the housing 30 of the power supply device 3 and inside the flow path 7c of the flow path 7. In other words, the low-temperature section 53 is a part of the heat pipe 5, and is a portion that is located on the flow path 7 side (the outside of the power supply device 3) of the partition wall 30a when the heat pipe 5 is assembled in the housing 30 of the power supply device 3. Specifically, the low-temperature section 53 is a portion that protrudes from the housing interior 30b of the power supply device 3 into the flow path inside 7c on the inlet portion 7a side of the flow path 7 when the heat pipe 5 is assembled in the housing 30 of the power supply device 3.

[0053] The low-temperature section 53 is thermally connected to the flow path interior 7c of the flow path 7. That is, the low-temperature section 53 is thermally connected to the coolant flowing through the flow path interior 7c of the flow path 7. That is, the low-temperature section 53 is cooled by the coolant flowing through the flow path interior 7c of the flow path 7, and is in a relatively low temperature state compared to the high-temperature section 51. Therefore, the heat collected from each of the multiple board-mounted components 33 to be cooled is transported to the low-temperature section 53. Furthermore, the low-temperature section 53 releases (radiates) the heat from each of the multiple board-mounted components 33 to be cooled to the coolant through heat exchange with the coolant.

[0054] The low temperature portion 53 is formed in a flat plate shape and extends from the high temperature portion 51. The main portion of the low temperature portion 53 extends in the +X direction along the XY plane in a state in which the main surface of the main portion of the high temperature portion 51 is arranged along the XY plane.

[0055] More specifically, as shown in FIG. 3 , when the heat pipe 5 is assembled in the housing 30 of the power supply device 3, the low-temperature section 53 penetrates the through-hole 30c of the partition wall 30a and extends from the high-temperature section 51 to the flow path interior 7c. A sealing member (not shown) is provided in this through-hole 30c between the heat pipe 5 and the partition wall 30a to prevent leakage of coolant from the flow path 7 into the housing interior 30b of the power supply device 3. Meanwhile, the housing 30 does not have any other connection portion spatially connected to the flow path 7 other than the through-hole 30c. Thus, in the cooling structure 1 according to the present disclosure, the only connection portion between the housing interior 30b of the power supply device 3 and the flow path 7 is the through-hole 30c. In other words, in the cooling structure 1, a sealing structure that prevents leakage of coolant from the flow path 7 into the housing interior 30b of the power supply device 3 only needs to be applied to at least the through-hole 30c.

[0056] As described above, in the cooling structure 1 according to this embodiment, the flow path 7 of the coolant for forced liquid cooling is arranged adjacent to the exterior of the housing 30 of the power supply device 3 (power conversion device) that mounts multiple board-mounted components 33 (electronic components) to be cooled, and the flow path interior 7c is spatially isolated from the housing interior 30b of the power supply device 3. Furthermore, in the cooling structure 1 according to this embodiment, the heat pipes 5 arranged from the housing interior 30b to the flow path interior 7c form a heat transport path that transports heat from each of the multiple board-mounted components 33 to the coolant flowing through the flow path interior 7c.

[0057] Conventionally, power supply units (power conversion units) have faced challenges in heat dissipation due to the increasing heat loss of components mounted on boards as semiconductors become more powerful. Furthermore, in the case of in-vehicle power supply units, miniaturization is required in anticipation of improved mountability as EVs become more diverse. For example, when power conversion is performed on large currents and high voltages, the control frequency increases, leading to progress in miniaturization, but heat dissipation from heat-generating components has become an issue.

[0058] For this reason, it has been common to arrange a cooling fluid flow path for forced liquid cooling inside the housing. However, arranging the flow path inside the housing has the problem of limiting the downsizing of the housing. Furthermore, when the flow path for the working fluid for cooling is formed by die-casting, a large-scale or extensive sealing structure must be applied to prevent fatal field defects such as damage to electronic components due to leakage of the working fluid from casting cavities, which has the problem of increasing the size of the housing. In other words, there is room for improvement in the downsizing of cooling structures including the flow path for the working fluid for cooling.

[0059] Furthermore, when a flow path is placed inside a housing, the cooling surface (heat dissipation surface) depends on the routing (layout) of the flow path, which limits the layout of components inside the housing. For example, in the past, a coolant flow path was formed inside a die-cast housing, and a heat-generating component was assembled in the housing, thereby thermally connecting the heat-generating component to the housing directly or indirectly via other components or members to cool it. In other words, there was room for improvement in the construction of the heat transport path from the heat-generating component to the flow path (cooling mechanism).

[0060] In the cooling structure 1 according to this embodiment, no flow path 7 is provided inside the housing 30b of the power supply device 3. As described above, the cooling structure 1 according to this embodiment is configured to collect and transport heat from each of the multiple board-mounted components 33 by using heat pipes 5 (heat transport members) to route the heat to the flow path 7 outside the housing 30, which is spatially isolated from the housing interior 30b.

[0061] Therefore, with the cooling structure 1 according to this embodiment, space for arranging the flow path 7 is not required inside the housing 30b. Also, there is no need to route the flow path 7 inside the housing 30b. This prevents an increase in size that would otherwise be required for arranging the flow path 7 inside the housing 30b, thereby enabling the miniaturization of the power supply device 3. Furthermore, with the cooling structure 1 according to this embodiment, the power supply device 3 can be mounted on a moving object such as a vehicle without having to arrange the coolant flow path 7 inside the housing 30b of the power supply device 3. This reduces the risk of the power supply device 3 being damaged in the field due to liquid leakage from the flow path 7. Furthermore, with the cooling structure 1 according to this embodiment, the flow path 7 is provided outside the housing 30 of the power supply device 3, thereby easing restrictions on component layout that would otherwise be imposed by arranging the flow path 7 inside the housing 30b.

[0062] Furthermore, in the cooling structure 1 according to this embodiment, the housing 30 of the power supply device 3 does not have any connection part spatially connected to the flow path 7 other than the through-hole 30c through which the heat pipe 5 passes. This makes it possible to realize a sealing structure using a sealing member disposed in the through-hole 30c. In other words, the cooling structure 1 according to this embodiment does not require the application of a large-scale sealing structure, and it is possible to suppress the increase in size that would otherwise accompany the application of a sealing structure, thereby realizing a miniaturized power supply device 3.

[0063] Furthermore, since a heat transport path is formed via the heat pipe 5, the position at which the low-temperature section 53 protrudes from the housing 30 can be changed as needed. In other words, the degree of freedom in arranging the flow path 7 relative to the housing 30 can be improved.

[0064] Hereinafter, other embodiments and modifications of the cooling structure 1 according to the present disclosure will be described with reference to the drawings. Note that the following description will mainly focus on differences from the above-described embodiments, and redundant description will be omitted as appropriate.

[0065] (Second embodiment) In the above embodiment, the cooling structure 1 in which the housing 30 is formed from a metal material such as die-casting has been exemplified, but the present invention is not limited to this.

[0066] For example, in the cooling structure 1 according to this embodiment, the housing 30 may be made of a material other than a material having thermal conductivity (heat conductor). For example, the housing 30 may be made of a material having no thermal conductivity.

[0067] As an example, the housing 30 may be made of a non-metallic material such as resin.

[0068] For example, an electromagnetic shielding layer is formed on the outer surface or inner surface of the housing 30. The electromagnetic shielding layer may be formed so as to cover the electronic components arranged inside the housing 30b, and may be provided on other surfaces besides the outer surface and inner surface of the housing 30. This electromagnetic shielding layer may be formed to an extent that it provides an electromagnetic shielding effect for the electronic components arranged inside the housing 30b.

[0069] The electromagnetic shielding layer may be a layer of a metal material formed on the outer or inner surface by, for example, plating or sputtering. Alternatively, the electromagnetic shielding layer may be realized as a thin metal film attached to the outer or inner surface. Alternatively, the electromagnetic shielding layer may be formed by applying a paint containing a metal material to the outer or inner surface.

[0070] As described above, in the cooling structure 1 according to this embodiment, the housing 30 is formed using a non-metallic material, which reduces the risk of blowholes occurring as in die-casting, i.e., it is possible to prevent the coolant from entering the housing interior 30b and reduce the risk of damage to the power supply device 3 due to leakage from the flow path 7. Furthermore, the degree of freedom in material selection is increased, which allows for cost reduction and weight reduction to be achieved.

[0071] (Third embodiment) In the above embodiment, the cooling structure 1 configured to be capable of simultaneously cooling (dissipating heat) a plurality of types of board-mounted components 33 has been exemplified, but the present invention is not limited to this.

[0072] For example, in the cooling structure 1 according to this embodiment, the heat pipe 5 may be configured to locally cool (dissipate heat) the power supply device 3, for example, to target only some of the board-mounted components 33. In the following, in this embodiment, a cooling structure 1 will be described in which only the MOSFET 33a is targeted for cooling, with heat being drawn to the flow path 7 by the heat pipe 5.

[0073] 5 and 6 are perspective views showing another example of the configuration of the cooling structure 1 according to the embodiment. Like FIG. 1, FIG. 5 illustrates an example of the cooling structure 1 viewed from above (+Z side). Like FIG. 2, FIG. 6 illustrates an example of the cooling structure 1 viewed from below (-Z side). FIG. 7 is a cross-sectional view showing an example of the configuration of the cooling structure 1 in FIG. 5. FIG. 7 illustrates an example of the ZX cross section viewed from the +Y side, as shown in VII-VII of FIGS. 5 and 6. FIG. 8 is a perspective view showing an example of the configuration of the heat pipe 5 in FIG. 5.

[0074] As shown in FIGS. 5 to 8, the high temperature section 51 of the heat pipe according to this embodiment corresponds to a single high temperature section that is formed by integrating the plurality of first high temperature sections 51a according to the first embodiment.

[0075] Specifically, the high-temperature section 51 according to this embodiment is thermally connected to each of the plurality of MOSFETs 33a to be cooled inside the housing 30b. That is, the high-temperature section 51 diffuses and collects heat from each of the plurality of MOSFETs 33a to be cooled inside the housing 30b.

[0076] The high temperature section 51 has a connection section extending from the low temperature section 53. The connection section of the high temperature section 51 is formed in a flat plate shape. When the main surface of the low temperature section 53 is arranged along the XY plane, the connection section of the high temperature section 51 extends along the XY plane to the -X side.

[0077] As an example, the high temperature portion 51 is formed by bending a flat portion extending along the main surface from the end of the connection portion with the low temperature portion 53 to form a bent portion 55. That is, the high temperature portion 51 according to this embodiment extends in the Z direction, similar to the first high temperature portion 51a according to the above-described embodiment.

[0078] Moreover, the high-temperature portion 51 formed by bending at the bending portion 55 extends to the +Y side, for example, along the arrangement of the MOSFETs 33a, and also extends to the -X side by further bending a portion to form a bending portion 56. In other words, the high-temperature portion 51 according to this embodiment includes a flat portion extending along the YZ plane and a flat portion extending along the ZX plane.

[0079] Thus, the flat portion extending along the YZ plane of the high temperature portion 51 according to this embodiment has a shape in which only the connection portion with the heat dissipation surface of the MOSFET 33a and its vicinity are integrated along the X direction for some of the first high temperature portions 51a among the plurality of first high temperature portions 51a according to the above embodiment, extending in the Z direction from the end portion on the +X side of the main portion of the high temperature portion 51. Similarly, the flat portion extending along the ZX plane of the high temperature portion 51 according to this embodiment has a shape in which only the connection portion with the heat dissipation surface of the MOSFET 33a and its vicinity are integrated along the X direction for some of the first high temperature portions 51a among the plurality of first high temperature portions 51a according to the above embodiment, extending in the Z direction from the end portion on the -Y side of the main portion of the high temperature portion 51.

[0080] This configuration also provides the same effects as the above-described embodiment. Furthermore, by adopting a shape of the heat pipe 5 that corresponds to the desired cooling target, it is possible to achieve further miniaturization, improved layout freedom, and weight reduction.

[0081] The technology according to this embodiment can be appropriately combined with at least one of the first and second embodiments.

[0082] (Fourth embodiment) In the above-described embodiments, the cooling structure 1 in which the flow path 7 and the housing 30 are disposed at different positions in a plan view has been exemplified, but the present invention is not limited to this.

[0083] The flow path 7 and the housing 30 may be arranged so as to overlap each other in plan view, as long as their interiors are spatially separated from each other.

[0084] As an example, the flow path 7 may be provided not only on the side of the housing 30 but also on the downward side (-Z side) thereof. In this case, the low-temperature section 53 may be bent or otherwise extended downward to protrude to the outside of the housing 30 and be thermally connected to the flow path interior 7c.

[0085] As an example, the housing 30 may have a shape that is recessed toward the housing interior 30b or hollowed out to allow a duct to pass through, in relation to a dead space in the housing interior 30b where components and the like are not placed. Also, the flow path 7 may be disposed in a space formed outside the housing 30 by recessing or hollowing out the housing 30 inward. In this case, the low-temperature section 53 may be bent or the like according to its positional relationship with the flow path 7, and may extend toward the flow path 7, protrude to the outside of the housing 30, and be thermally connected to the flow path interior 7c.

[0086] As an example, a gap may be provided between the housing 30 and the flow path 7. In other words, the housing 30 and the flow path 7 may share a part of each other, their outer surfaces may be in contact with each other, or they may be arranged at positions spatially separated from each other.

[0087] Even with these configurations, the same effects as those of the above-described embodiment can be obtained. Furthermore, because a heat transport path is formed via the heat pipe 5, the flow path 7 can be configured to be provided below the housing 30 of the power supply device 3, to be provided in a recessed or hollowed-out portion of the housing 30, or to be spatially separated from the housing 30, as long as the low-temperature section 53 protrudes from a corresponding position in a corresponding direction. In other words, even if the flow path 7 and the housing 30 are arranged to overlap in a plan view, there is no need to route the flow path 7 in accordance with the arrangement of the electronic components to be cooled, and an increase in size due to such routing can be suppressed.

[0088] According to at least one of the embodiments described above, it is possible to reduce the size of the cooling structure including the flow path for the working fluid for cooling.

[0089] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0090] 1 Cooling structure 3 Power supply unit (power conversion unit) 30 Case 30a Bulkhead part 30b Inside the housing 30c penetration part 31 PCB 33 PCB Mounted Components 33a MOSFET (power semiconductor) 33b Trans 33c electrolytic capacitor 33d Choke coil 5 heat pipes 51 High temperature section 53 Low temperature section 55,56 Bent section 57 Cutout 7 Flow path 7a Inlet 7b Outlet 7c Inside the flow path

Claims

1. a housing of a power conversion device in which a plurality of electronic components to be cooled are disposed; a flow path arranged outside the housing around the housing, the flow path through which the working fluid flows being spatially isolated from the inside of the housing; a heat transport member that is disposed from the inside of the housing to the inside of the flow path of the flow path, and has a high-temperature portion that is thermally connected to each of the plurality of electronic components inside the housing, and a low-temperature portion that is thermally connected to the working fluid inside the flow path that is outside the housing, and forms a heat transport path that transports heat from each of the plurality of electronic components to the working fluid; Cooling structure.

2. The housing is formed of a metal material. The cooling structure according to claim 1 .

3. The housing is formed of a non-metallic material. The cooling structure according to claim 1 .

4. An electromagnetic shielding layer is formed on the outer surface or the inner surface of the housing. The cooling structure according to claim 3 .

5. the low-temperature portion extends from the high-temperature portion and protrudes to the outside of the housing through a penetration portion provided in the housing; The cooling structure according to any one of claims 1 to 4.

6. The low-temperature portion extends through the through-portion to the inside of the flow path outside the housing. The cooling structure according to claim 5 .

7. Further comprising a sealing member disposed in the penetration portion. The cooling structure according to claim 5 .

8. The side of the housing where the flow path is located is adjacent to the side of the housing where the flow path is located, The housing does not have a connection portion spatially connected to the flow path other than the through portion. The cooling structure according to claim 5 .

9. The through-hole is provided in a partition wall portion common to the housing and the flow path. The cooling structure according to claim 5 .

10. A gap is provided between the housing and the flow path. The cooling structure according to claim 5 .

11. The flow path does not overlap with the housing in a plan view. The cooling structure according to any one of claims 1 to 4.

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