Case

Abstract

A case according to the present invention that has a case member in which an electronic component is accommodated in an inner section thereof heated by a heat source comprises at least one of: a heat insulating part that is provided to an inner wall of the electronic component on the upper side in the gravity direction and has a space communicating with the inner section; and a condensation suppression part that is formed from a different material from the case member.

Description

case

[0001] The present invention relates to a case.

[0002] Patent Document 1 discloses an electrical connection box that uses a sealed insulating layer to block heat from the high-temperature air stagnating in the upper part of the engine compartment, making it difficult for the inside of the housing to heat up, and suppresses condensation on relays that radiate heat from inside the housing to the outside via electric wires.

[0003] JP 2023-65722 A

[0004] In a case where the inside is warmer than the outside, condensation can occur when the air inside the case is cooled by the ceiling. However, a sealed insulation layer may not be effective enough to prevent condensation, and if an insulation layer is installed across the entire ceiling to prevent the effects of cold outside air, the entire case would become larger vertically.

[0005] The present invention has been made in view of these problems, and aims to more effectively suppress condensation while preventing the entire case from becoming larger in the vertical direction.

[0006] According to one aspect of the present invention, there is provided a case having a case member that houses an electronic component inside, the interior of which is heated by a heat source, and which is equipped with at least one of an insulating section provided on an inner wall above the electronic component in the direction of gravity and having a space that communicates with the interior, and a condensation suppression section made of a material different from the case member.

[0007] According to the above-described embodiment, when a temperature difference occurs within the case member, warm air expands and becomes lighter due to a decrease in density, causing it to rise, while cold air descends. This generates convection within the case member, allowing the warm air within the case member to pass through the insulation section, which has a space communicating with the interior, due to convection. Therefore, the insulation section prevents the cold from the outside from being transmitted to the bottom surface of the insulation section (the inner wall surface of the case). Furthermore, by warming the space with the warm air within the case member, a temperature drop on the bottom surface of the insulation section is suppressed, thereby preventing condensation on the bottom surface of the insulation section. Furthermore, by providing a through-hole above the electronic components to be protected from water in the direction of gravity, water droplets resulting from condensation can be prevented from falling onto the electronic components, eliminating the need for a sealed insulation layer across the entire ceiling. Furthermore, by providing a condensation-suppressing member above the electronic components to be protected from water in the direction of gravity, water droplets resulting from condensation can be prevented from falling onto the electronic components. Furthermore, because the condensation suppression member is attached to the inner wall of the case member, the dead space between the inner wall of the case member and the electronic components can be effectively utilized, which means that there is no need to change the overall size of the case, and therefore the overall vertical size of the case can be kept from increasing.

[0008] FIG. 1 is a schematic diagram of a case according to a first embodiment of the present invention. FIG. 2 is a perspective view of a main portion of the case. FIG. 3 is an explanatory diagram of condensation suppression using convection by using through holes. FIG. 4 is a diagram schematically illustrating the flow of convection within the case near the ceiling surface. FIG. 5 is an explanatory diagram of the relationship between the through holes and a heat source. FIG. 6 is a diagram schematically illustrating the process of drilling a through hole. FIG. 7 is a diagram illustrating a first modified example. FIG. 8 is a diagram illustrating a second modified example. FIG. 9 is a diagram illustrating a first modified example of a through hole. FIG. 10 is a diagram illustrating a second modified example of a through hole. FIG. 11 is a diagram illustrating a third modified example of a through hole. FIG. 12 is a diagram illustrating a fourth modified example of a through hole. FIG. 13 is a diagram illustrating a first modified example of a heat source. FIG. 14 is a diagram illustrating a second modified example of a heat source. FIG. 15 is a diagram illustrating a first modified example of a heat insulating section. FIG. 16 is a diagram illustrating a second modified example of a heat insulating section. FIG. 17 is a schematic diagram of a case according to a first embodiment of the present invention. FIG. 18 is a perspective view of a main portion of the case. FIG. 19 is a diagram illustrating a modified example of the case. Fig. 20 is a diagram illustrating a first modified example of the condensation suppression unit, Fig. 21 is an explanatory diagram of condensation suppression by the condensation suppression unit of the first modified example, and Fig. 22 is a diagram illustrating a second modified example of the condensation suppression unit.

[0009] First Embodiment A first embodiment of the present invention will now be described with reference to the accompanying drawings.

[0010] Fig. 1 is a schematic diagram of a case 1 according to a first embodiment of the present invention. Fig. 2 is a perspective view of a main portion of the case 1. The case 1 is mounted on a vehicle and includes an electronic component 2 and a case member 10 that houses the electronic component 2 in an interior 11. The electronic component 2 is a wiring connector that requires protection from water to prevent short circuits and electrolytic corrosion caused by water exposure. The electronic component 2 may also be another electronic component that requires protection from water.

[0011] The case member 10 is made of an aluminum or iron-based metal material, such as an aluminum alloy or steel material. The case member 10 is container-shaped with one side open, and has a flange portion 1a provided around the opening and a mating surface 1b formed on the flange portion 1a. The case member 10 is attached to the gearbox case 5 from the side (left side in FIG. 1 ) via the flange portion 1a, and has a ceiling wall 12 having a ceiling surface 12a facing the interior 11, a side wall 13 on which the electronic components 2 are provided, and a side wall 14 connected to the side wall 13 and arranged opposite the opening of the case member 10.

[0012] The gearbox case 5 is a separate case from the case member 10, and houses gear mechanisms such as a reduction mechanism and a differential mechanism. The gearbox case 5 has a flange portion 5a provided around the opening and a mating surface 5b formed on the flange portion 5a, and the case member 10 is fastened to the gearbox case 5 with bolts, with the mating surfaces 1b and 5b mated. The inside of the case member 10 (interior 11) and the inside of the gearbox case 5 (interior 51) communicate with each other through an opening bordered by the flange portions 1a and 5a.

[0013] Oil OL is stored in the gearbox case 5. After being heated by frictional heat generated by gears of the gear mechanism, etc., the oil OL is stored in the bottom of the gearbox case 5. The oil OL stored in the bottom of the gearbox case 5 constitutes a heat source that warms the interior 11 of the case member 10. The oil OL as a heat source is further stored in the case member 10 through openings bordered by the flange portions 1a, 5a. Therefore, the internal space of the case member 10 and the gearbox case 5 connected to the case member 10 has an oil reservoir R that stores the oil OL.

[0014] A control valve unit 3 is further housed within the case member 10. The control valve unit 3 is housed within the case member 10 and the gearbox case 5. The control valve unit 3 includes a control valve and oil passages that control the pressure of the oil OL to the hydraulic actuator, and the oil OL stored in the bottom of the gearbox case 5 is supplied to the control valve unit 3 by an oil pump.

[0015] 1 and 2 , the case member 10 has an inner wall IW on the upper side in the direction of gravity of the electronic component 2 (upper side in FIG. 1 ), and a through hole H provided in the inner wall IW, both ends of which open into the interior 11 of the case member 10. The upper side in the direction of gravity is the upper side in the direction of gravity when the case 1 is mounted on a vehicle, and the up-and-down direction in FIG. 1 corresponds to the direction of gravity when the case 1 is mounted on a vehicle. The through hole H has a portion that overlaps with the electronic component 2 when viewed in the direction of gravity. The following description of the direction of gravity and the sideways sides is based on the assumption that the case 1 is mounted on a vehicle.

[0016] The inner wall IW has a protrusion B, and the through hole H is provided in the protrusion B. The protrusion B is formed as a portion that rises from the ceiling surface 12a of the ceiling wall 12 that forms the inner wall IW toward the interior 11, and has a portion that overlaps with the electronic component 2 when viewed in the direction of gravity. As shown in FIG. 2 , the protrusion B further connects to the side wall 13 from the side above the electronic component 2 in the direction of gravity, thereby covering the installation portion of the electronic component 2. The protrusion B is provided to cover the entire electronic component 2 and overlaps with the entire electronic component 2 when viewed in the direction of gravity. Note that the protrusion B may be provided in at least one of the following modes: having a portion that overlaps with the electronic component 2 when viewed in the direction of gravity, connecting to the side wall 13, and overlapping with the entire electronic component 2 when viewed in the direction of gravity.

[0017] The protrusion B has a rectangular parallelepiped shape and has side walls W1 to W3 that face in a direction different from the direction facing the side wall 13 on which the electronic component 2 is provided (the rearward direction in FIG. 1 ). The side walls W1 and W2 constitute side walls that face in a direction (left-right direction in FIG. 1 ) that intersects (e.g., perpendicular to) the direction facing the side wall 13, and the side wall W3 constitutes a side wall that faces in the opposite direction (the forward direction in FIG. 1 ) from the direction facing the side wall 13.

[0018] The through hole H penetrates the side walls W1, W2 by extending laterally (left-right direction in FIG. 1 ) intersecting the direction facing the side wall 13 and penetrating the protruding portion B. The through hole H has a first opening H1 that opens from the side wall W1 to the interior 11 and a second opening H2 that opens from the side wall W2 to the interior 11, and is open to the interior 11 at both ends by the first and second openings H1, H2.

[0019] 3 is an explanatory diagram of condensation suppression using through holes H that utilize convection. When the temperature inside the case member 10 is high and the outside air is low, the warm air inside the case member 10 is cooled by the low-temperature outside air, reducing the amount of saturated water vapor in the air inside the case member 10. As a result, the moisture that the air can no longer contain condenses, causing condensation. Therefore, inside the case member 10 that is warmed by the oil OL, condensation, indicated by the black circles, can occur on the inner surface of the wall of the case member 10 that comes into contact with the cold outside air.

[0020] On the other hand, when the inside of the case member 10 is heated by the oil OL and a temperature difference occurs within the case member 10, the warm air expands and becomes lighter due to a decrease in density, so it rises (solid arrow), and conversely, the cold air descends (dashed arrow), so convection occurs within the case member 10.

[0021] In the case member 10, in order to utilize such convection to suppress condensation, the through hole H is provided in the inner wall IW above the electronic component 2 in the direction of gravity, and opens at both ends to the interior 11 which is heated by oil OL as a heat source.

[0022] This allows warm air inside the case member 10 to convect through the insulation portion (i.e., the space S formed by the through-holes H) that has the space S communicating with the interior 11. Therefore, providing the insulation portion makes it difficult for the cold outside to be transmitted to the bottom surface of the insulation portion (the surface of the inner wall IW where the through-holes H are provided). Furthermore, by warming the space S with the warm air inside the case member 10, a temperature drop on the bottom surface of the insulation portion is suppressed, making it possible to suppress condensation on the bottom surface of the insulation portion. Furthermore, because the through-holes H are provided above the electronic components 2 to be protected from water in the direction of gravity, it is possible to prevent water droplets resulting from condensation from falling onto the electronic components 2, eliminating the need to provide a sealed insulation layer over the entire ceiling wall 12. This prevents the overall case 1 from becoming larger in the vertical direction (the direction of gravity).

[0023] The through-holes H are provided in the protruding portion B. This makes it possible to provide the through-holes H in the convection flow, making it easier to guide warm air into the through-holes H, and thus making it easier to suppress condensation. Furthermore, in relation to the electronic components 2 located on the lower side in the direction of gravity, the bottom surface B1 of the protruding portion B, which is the portion where condensation should be suppressed, is kept away from the outside air by the thickness of the protruding portion B (the thickness in the vertical direction in FIG. 3 ), and therefore the bottom surface B1 is also less likely to cool.

[0024] Within the case member 10 near the side wall 14, the air is cooled by the cold outside air, so convection tends to flow downward. On the other hand, when the warm air rises and hits the ceiling surface 12a, it moves sideways along the ceiling surface 12a and flows toward the side wall 14 where the cold air has disappeared.

[0025] 4 is a diagram schematically illustrating the flow of convection within the case member 10 near the ceiling surface 12a, with one end of the first opening H1 of the through-hole H opening in a direction opposite to the direction of such convection within the interior 11 (toward the left in FIG. 4 ). This allows warm air to be efficiently sent to the through-hole H, making it easier to suppress condensation. In other words, the direction of convection is the direction of the convection flow, and the first opening H1 opens in a direction opposite to the direction of convection, in a direction that does not interfere with the convection, in a direction that receives the flow, facing upstream or in the flow direction (for example, opening directly in front when viewed from the flow direction).

[0026] The through holes H further extend in the direction of convection. As a result, the through holes H extend in a direction that does not interfere with the convection, making it easier to guide warm air to the through holes H and easier to suppress condensation.

[0027] 5 is an explanatory diagram of the relationship between the through-holes H and the oil OL as a heat source. In FIG. 5, the through-holes H are schematically shown together with the oil OL as a heat source as viewed in the direction of gravity. When the warm air heated by the oil OL as a heat source rises and hits the ceiling surface 12a (see FIG. 4), it diffuses in all directions as shown in FIG. 5.

[0028] In contrast, the first opening H1 of the through hole H is provided so as to open toward the center of the oil OL serving as the heat source when viewed in the direction of gravity. This allows warm air that hits the ceiling surface 12a and moves while diffusing in all directions to be guided into the through hole H, making it easier to suppress condensation. The through hole H thus provided opens in a direction along the ceiling surface 12a (see FIG. 4). The center (central portion) of the heat source refers, for example, to the location of the heat source where the temperature is the highest (where the temperature is most difficult to decrease), or the area around the center of the component or location that serves as the heat source.

[0029] The first opening H1 of the through hole H may be provided at a position overlapping with the oil OL as a heat source when viewed in the direction of gravity. Even in this case, by opening the first opening H1 toward the center of the oil OL as a heat source when viewed in the direction of gravity, it is possible to guide the warm air that collides with the ceiling surface 12a near the first opening H1 and diffuses and moves in all directions to the through hole H.

[0030] As shown in Figure 3, thickness T1 (the thickness between the bottom surface of through hole H and bottom surface B1 of protrusion B), which is the wall thickness T of the protrusion B at the portion that forms through hole H, is smaller than the size or dimension (opening height) of through hole H in the thickness direction (the up-and-down direction in Figure 3). The wall thickness T of protrusion B, including thickness T1, is smaller than the opening height of through hole H. Thickness T1 is the wall thickness of protrusion B on the lower side of through hole H in the direction of gravity, and thickness T2 is the wall thickness of protrusion B on the upper side of through hole H in the direction of gravity.

[0031] The surface area of ​​the through hole H is enlarged within a range in which the thickness T1 is smaller than the opening height of the through hole H. Therefore, the space S (insulating portion) formed by the through hole H is enlarged, making it difficult for the cold of the outside air to be transmitted to the interior 11, and since a larger amount of warm air from inside the case member 10 enters the through hole H, the rate at which the temperature of the protruding portion B drops can be slowed down, making it easier to suppress condensation.

[0032] The cross section of the through hole H perpendicular to the direction in which the through hole H extends is round, and the through hole H is configured as a circular hole. Therefore, the thicknesses T1 and T2 are smaller than the diameter of the through hole H. By employing a round through hole H in the case member 10, it is possible to provide the through hole H simply by drilling a hole from the mating surface 1b side of the case member 10, as shown by the arrow in FIG. 6 .

[0033] 2, the bottom surface B1 of the protrusion B (the outer peripheral surface of the bottom wall formed by the bottom surface of the through hole H and the surface of the electronic component 2 on the upper side in the direction of gravity) has a shape that follows the shape of the bottom of the cross section of the through hole H perpendicular to the direction in which the through hole H extends. A plurality of through holes H (four in this example) are provided, and the plurality of through holes H are arranged side by side in a direction facing the side wall 13. For this reason, the bottom surface B1 is formed in a wavy shape. The surface of the side wall W3 also has a shape that follows the shape of the through hole H and is formed in a curved shape.

[0034] By shaping the bottom surface B1 to conform to the through hole H, the thickness of the bottom surface B1 can be made uniform, and a structure of the protrusion B can be obtained that is less likely to produce voids when the through hole H is manufactured by casting. Furthermore, in the case member 10, a structure of the protrusion B that is less likely to produce voids during casting, including the side wall W3, can be obtained.

[0035] 7 is a diagram showing a first modified example. The through hole H of the first modified example is provided in the protruding portion B of the first modified example. The protruding portion B of the first modified example is not connected to the side wall 13 on which the electronic component 2 is provided, and the through hole H of the first modified example opens into the interior 11 from the side wall W4 of the protruding portion B of the first modified example, which faces the side wall 13. The case member 10 can also suppress condensation by having such a through hole H and protruding portion B.

[0036] 1 to 3 , the first opening H1 opens into the interior 11 from a side wall W1 of the protrusion B that faces in a direction different from the direction facing the side wall 13 on which the electronic component 2 is provided, and the second opening H2 opens into the interior 11 from a side wall W2 of the protrusion B that faces in a direction different from the direction facing the side wall 13. This prevents the convection flow that has passed through the through hole H from being obstructed by the electronic component 2, improving the convection flow within the through hole H. The side wall W3 (see FIGS. 1 and 2 ) also faces in a direction different from the direction facing the side wall 13.

[0037] 8 is a diagram showing a second modified example. The through hole H of the second modified example is provided in the protrusion B of the second modified example, and the wall thicknesses T1 and T2 of the protrusion B of the second modified example at the portion where the through hole H of the second modified example is formed are larger than the size or dimension (opening height) of the through hole H of the second modified example in the thickness direction (the vertical direction in FIG. 8 ). Therefore, in this case, the wall thicknesses T1 and T2 of the protrusion B of the second modified example are larger than the through hole H of the second modified example, and the surface area of ​​the through hole H is correspondingly smaller. Meanwhile, the case 1 can also suppress condensation by having such through hole H and protrusion B.

[0038] 9 to 12 are diagrams illustrating modified examples of the through hole H. As shown in FIG. 9 , the inner wall IW may not have the protrusion B, and the through hole H may be provided in a portion of the inner wall IW that does not have the protrusion B. In this example, an inverted U-shaped through hole H, which opens at both ends from the ceiling surface 12a to the interior 11, is provided in the ceiling wall 12 that forms the inner wall IW. The first opening H1 opens to the interior 11 along the direction of gravity, thereby opening in the opposite direction to the convection direction of rising warm air before it hits the ceiling surface 12a and moves sideways. Even with this configuration, the first opening H1 makes it easier to guide the rising warm air to the through hole H, thereby making it easier to suppress condensation.

[0039] As shown in Fig. 10, the through hole H may be provided in the protruding portion B and may have a first opening H1 facing downward in the direction of gravity. In this example, as in the case of Fig. 9, the first opening H1 opens to the interior 11 in the direction of gravity. In this example, the through hole H is formed in an L-shape oriented as shown, and the second opening H2 opens to the interior 11 in a direction along the ceiling surface 12a. Even with this configuration, as in the case of Fig. 9, the first opening H1 opening in the direction opposite to the direction of convection can make it easier to suppress condensation.

[0040] 10 , the protrusion B may not overlap the entire electronic component 2 when viewed in the direction of gravity, but may overlap a part of the electronic component 2. On the other hand, if the protrusion B overlaps the entire electronic component 2 when viewed in the direction of gravity, this is preferable because it can effectively prevent water droplets resulting from condensation from falling onto the electronic component 2.

[0041] 11 , the through hole H may be provided in the protruding portion B that is continuous with the side wall 14, and may have a first opening H1 that opens into the interior 11 in a direction along the ceiling surface 12a. In this example, the through hole H is formed in an L-shape oriented as shown, and the second opening H2 opens into the interior 11 in a direction along the direction of gravity. Even with this configuration, the first opening H1 that opens against the direction of convection can make it easier to suppress condensation.

[0042] As shown in FIG. 12 , the through-hole H may be provided in the protrusion B and may have a first opening H1 that opens in a direction facing the sidewall 13 on which the electronic component 2 is provided. In this example, the first opening H1 opens in a direction opposite to the convection direction formed by warm air that rises, hits the ceiling surface 12a, and moves along the ceiling surface 12a toward the sidewall 13. This configuration also makes it easier to suppress condensation. The first opening H1 may open in a direction along the ceiling surface 12a other than the direction facing the sidewall 13, facing opposite to the convection direction.

[0043] 12, the through-hole H may be rectangular. When the through-hole H is rectangular (rectangular parallelepiped) and round (cylindrical) in shape, the rectangular through-hole H has a larger surface area than the cylindrical through-hole H when the through-holes have the same volume and length.

[0044] 12, condensation can be effectively suppressed by improving the efficiency of heat exchange with warm air compared to when the through-hole H is round. In this case, by making the bottom surface B1 of the protrusion B flat, the bottom surface B1 can be shaped to conform to the through-hole H, and a structure that is less likely to produce voids during casting can be obtained.

[0045] 13 and 14 are diagrams showing modified examples of the heat source. The heat source may be a heat-generating electronic component or other component. For example, since high-temperature oil OL flows through the control valve unit 3 while the vehicle is running, the control valve unit 3 also becomes a heat source. Furthermore, the heat source may be located at the same height as the electronic component 2 as shown in FIG. 13, or may be located higher than the electronic component 2 as shown in FIG. 14. The heat source may also be located outside the case member 10.

[0046] Even in these cases, by providing the through-holes H in the protruding portions B, it is possible to provide the through-holes H in the convection flow. This makes it easier to guide warm air to the through-holes H, making it easier to suppress condensation.

[0047] The protrusion B may be cast together with the through hole H when the case member 10 is cast, or if the case member 10 is made of an iron-based metal material, the protrusion B may be welded to the inner wall IW with the through hole H formed. The protrusion B may be cast when the case member 10 is cast, or may be welded to the inner wall IW, without the through hole H being formed, or the through hole H may be formed by drilling a hole in the protrusion B without the through hole H being formed. The protrusion B being welded to the inner wall IW is also included in the concept of the inner wall IW having the protrusion B.

[0048] The protrusion B does not have to be rectangular parallelepiped-shaped. For example, if the protrusion B is shaped to overlap the entire electronic component 2 when viewed in the direction of gravity and to follow the outer shape of the electronic component 2, unnecessary portions can be eliminated, which is preferable because weight and costs can be reduced.

[0049] The space S may be defined by a wall portion provided with a gap on the inner wall IW by bolts or the like. This also makes it possible to provide the space S within the convection flow. The wall portion also functions as a roof covering the electronic components 2, and can also catch water droplets that may form when condensation occurs.

[0050] FIG. 15 is a diagram showing a first modified example of the heat insulating portion. In this example, the space S is defined by the inner surface of the recessed portion D. The recessed portion D differs from the through-hole H in that it does not open to the side wall W2 opposite the first opening H1. Therefore, in this example, the second opening H2 is not formed. In this example, the heat insulating portion is formed by a protruding portion B provided on the surface of the inner wall IW of the electronic component 2 and protruding toward the inside of the case member 10, and the recessed portion D is provided in the protruding portion B. Even in this example, warm air from within the case member 10 flows into the recessed portion D due to convection. This warm air from within the case member 10 heats the inside of the recessed portion D, thereby suppressing a temperature drop on the bottom surface of the heat insulating portion and suppressing condensation on the bottom surface of the heat insulating portion.

[0051] 16 is a diagram showing a second modified example of a heat insulating section. In this example, a wall section W20 is provided on the inner wall IW on the upper side in the direction of gravity of the electronic component 2. The wall section W20 has a U-shaped cross section and includes a bottom wall W21 and side walls W22 and W23 rising from both ends of the bottom wall W21 in the width direction (left-right direction in FIG. 16 ). The side walls W22 and W23 have ends E21 and E22 on the opposite side from the side connected to the bottom wall W21, and extend approximately parallel to each other from the bottom wall W21.

[0052] The wall W20 is attached to the ceiling surface 12a at its ends E21 and E22. The bottom wall W21 faces the ceiling surface 12a, and the side wall W22 faces the side wall 14 (see FIGS. 1 and 2). The wall W20 is made of the same metal material as the case member 10, and is welded to the ceiling surface 12a at its ends E21 and E22.

[0053] A gap C is formed between the wall portion W20 and the inner wall IW above the electronic component 2 in the direction of gravity. The gap C is formed as a space S surrounded by the bottom wall W21, the side walls W22 and W23, and the ceiling wall 12, and is formed between the bottom wall W21 and the ceiling surface 12a. The gap C is formed in a rectangular parallelepiped shape. In this example, a heat insulating section is formed having the space S defined by the gap C between the wall portion W20 and the surface of the inner wall IW.

[0054] Warm air that is heated inside the case member 10 and hits the ceiling surface 12a near the gap C outside the wall portion W20 passes through the gap C by convection, thereby heating the inside of the gap C. Therefore, even with such a wall portion W20, it is possible to suppress condensation on the surface of the wall portion W20.

[0055] The gap C may be composed of a plurality of gaps, such as gaps in a laminated structure or a honeycomb structure, etc. The gap C may be formed so as to extend in a direction different from that shown in FIG. 16 when viewed in the direction of gravity.

[0056] The wall W20 may be formed of a resin or other material with a lower thermal conductivity than the case member 10. This allows for the effect of warming the inside of the wall W20 through convection and the effect of making the wall W20 less likely to be cooled by outside air, synergistically suppressing condensation on the surface of the wall W20. In such cases, the wall W20 may be attached to the inner wall IW.

[0057] Next, the main effects of Case 1 will be described.

[0058] (1-1) A case 1 has a case member 10 that houses an electronic component 2 in an interior 11, and the interior 11 is heated by oil OL as a heat source. The case 1 has an insulating section (i.e., a space S formed by a through hole H) that is provided on an inner wall IW above the electronic component 2 in the direction of gravity and has a space S that communicates with the interior 11.

[0059] This configuration prevents external cold from being transmitted to the bottom surface of the thermal insulation. Furthermore, the space S communicating with the interior 11 allows warm air within the case member 10 to pass through the space S by convection. The warm air within the case member 10 warms the inside of the space S, suppressing a temperature drop on the bottom surface of the thermal insulation and preventing condensation on the bottom surface of the thermal insulation. Furthermore, the space S is provided above the electronic components 2 (in the direction of gravity) that need to be protected from water, preventing water droplets from condensation from falling onto the electronic components 2. This eliminates the need to provide a sealed insulation layer across the entire ceiling wall 12. This prevents the overall size of the case 1 from increasing vertically (in the direction of gravity). Furthermore, this configuration also prevents condensation from occurring around the thermal insulation, reducing the amount of moisture in the air while the thermal insulation suppresses condensation. This allows condensation to be suppressed even when the temperature inside the case member 10 is uniformly lowered.

[0060] (2) The space S is defined by the inner wall of the through hole H. With this configuration, the space S inside the insulation section is penetrated, which makes it easier to guide the flow of warm air generated by convection into the space S. Therefore, by heating the inside of the through hole H with the warm air inside the case member 10, it is possible to suppress a decrease in temperature of the bottom surface of the insulation section and suppress condensation on the bottom surface of the insulation section.

[0061] (3) The heat insulating portion is formed by a protrusion B provided on the surface of the inner wall IW of the electronic component 2 and protruding toward the interior 11 of the case member 10, and the through-hole H is provided in the protrusion B. With this configuration, the through-hole H can be provided in the flow of warm air that is heated by the oil OL as a heat source, rises, hits the ceiling surface 12a, and moves so as to diffuse in all directions, making it easier to guide the warm air to the through-hole H and to suppress condensation. In addition, the bottom surface B1 of the protrusion B, where condensation should be suppressed, is kept away from the outside air by the thickness of the protrusion B, which also has the effect of making the bottom surface B1 less likely to cool.

[0062] (4) The through hole H has a first opening H1 that opens in a direction opposite to the direction of convection generated in the interior 11. According to this configuration, the first opening H1 opens in a direction opposite to the opposite direction, so that warm air can be efficiently sent to the through hole H without interfering with the convection, which makes it easier to suppress condensation.

[0063] (5) The through holes H extend in the direction of convection. With this configuration, the through holes H extend in a direction that does not interfere with the flow of convection, making it easier to guide warm air into the through holes H and to suppress condensation.

[0064] (6) The through hole H has a first opening H1 that opens toward the center of the oil OL serving as a heat source when viewed in the direction of gravity. Air is heated by the oil OL serving as a heat source, rises, hits the ceiling surface 12a, and moves while diffusing in all directions. However, with this configuration, the through hole H opens toward the center of the oil OL serving as a heat source, so that the warm air diffusing in all directions from the center can be guided to the through hole H.

[0065] (7) The through hole H is round in a cross section perpendicular to the extending direction of the through hole H. According to this configuration, the through hole H can be provided simply by drilling.

[0066] (8) The through holes H may be square in a cross section perpendicular to the direction in which the through holes H extend. According to this configuration, when compared with a case in which the through holes H are round, when the through holes H have the same volume and length, the surface area of ​​the rectangular parallelepiped through holes H is larger than that of the cylindrical through holes H. This increases the efficiency of heat exchange with warm air and makes it possible to efficiently suppress condensation.

[0067] (9) The through hole H has first and second openings H1, H2 that open to the interior 11 in the side walls W1, W2 of the protrusion B, and the first and second openings H1, H2 open in a direction different from the direction facing the side wall 13 on which the electronic component 2 is provided. With this configuration, it is possible to prevent the flow of warm air that has passed through the through hole H from being obstructed by the electronic component 2, and the flow of warm air in the through hole H is improved.

[0068] (10) A gearbox case 5 serving as a separate case is coupled to the case member 10, and the through hole H has a first opening H1 that opens toward the gearbox case 5. According to this configuration, in the case where the gearbox case 5 has an oil reservoir R for oil OL, which serves as a heat source, or where the control valve unit 3 is present, as in the present embodiment, the first opening H1 opens toward the oil OL, which serves as a heat source, and warm air can be efficiently sent to the through hole H by convection, making it easier to suppress condensation.

[0069] (11) A gearbox case 5 as a separate case is coupled to the case member 10, and an oil reservoir R is provided in the internal space (i.e., the interior 11 and the interior 51) defined by the coupled gearbox case 5, and the through-hole H has a first opening H1 that opens toward the center of the oil reservoir R when viewed in the direction of gravity. Air is heated by the oil OL, which is a heat source, and rises, then hits the ceiling surface 12a and moves while diffusing in all directions. However, with this configuration, the first opening H1 opens toward the center of the oil reservoir R, so that warm air diffusing in all directions from directly above the center of the oil reservoir R can be guided to the through-hole H.

[0070] (12) The through-hole H extends along the ceiling of the case member 10. With this configuration, the warm air that is heated by the oil OL as a heat source, rises, hits the ceiling surface 12a, and moves along the ceiling so as to diffuse in all directions can be guided to the through-hole H.

[0071] (13) The thickness T1 of the portion forming the bottom wall of the through hole H is thinner than the opening height of the through hole H. With this configuration, the space S formed by the through hole H is larger, making it difficult for the cold of the outside air to be transmitted to the bottom surface B1 of the protruding portion B, and since a larger amount of warm air from inside the case member 10 enters the through hole H, the rate at which the temperature of the bottom surface B1 of the protruding portion B decreases can be slowed down, making it easier to suppress condensation.

[0072] (14) The bottom surface B1 of the protrusion B has a shape that follows the shape of the bottom of the cross section of the through hole H that is perpendicular to the extension direction of the through hole H. With this configuration, the thickness of the bottom wall of the through hole H can be made uniform, and a structure of the protrusion B that is less likely to produce voids when the through hole H is manufactured by casting can be obtained.

[0073] (15) The space S may be defined by the inner wall of the recessed portion D. According to this configuration, the recessed portion D is in communication with the interior 11 of the case member 10, and therefore, convection causes the warm air in the case member 10 to flow into the recessed portion D. Therefore, by heating the inside of the recessed portion D with the warm air in the case member 10, a decrease in the temperature of the bottom surface of the heat insulating portion can be suppressed, and condensation on the bottom surface of the heat insulating portion can be suppressed.

[0074] (16) In this case, the heat insulating portion can be formed by a protrusion B provided on the surface of the inner wall IW of the electronic component 2 and protruding toward the inside of the case member 10, and the recess D can be provided in the protrusion B. With this configuration, the recess D can be provided in the flow of warm air that is heated by the oil OL as a heat source, rises, hits the ceiling surface 12a, and moves so as to diffuse in all directions, making it easier to guide the warm air to the recess D and to suppress condensation. In addition, the bottom surface B1 of the protrusion B, where condensation should be suppressed, is kept away from the outside air by the thickness of the protrusion B, which also has the effect of making the bottom surface B1 less likely to cool.

[0075] (17) The case member 10 may include a wall portion W20 provided on the inner wall IW above the electronic component 2 in the direction of gravity, and the heat insulating portion may have a space S defined by a gap C between the wall portion W20 and the surface of the inner wall IW. With this configuration, heated air inside the case member 10 passes through the gap C by convection, and the inside of the gap C is heated, thereby making it possible to suppress condensation on the outer peripheral surface of the wall portion W20.

[0076] Second Embodiment A second embodiment of the present invention will now be described with reference to the accompanying drawings.

[0077] Fig. 17 is a schematic diagram of a case 1 according to a second embodiment of the present invention. Fig. 18 is a perspective view of a main portion of the case 1. The case 1 is mounted on a vehicle and includes an electronic component 2 and a case member 10 that houses the electronic component 2 in an interior 11. The electronic component 2 is a wiring connector that requires protection from water to prevent short circuits and electrolytic corrosion caused by water exposure. The electronic component 2 may also be another electronic component that requires protection from water.

[0078] The case member 10 is made of an aluminum or iron-based metal material, such as an aluminum alloy or steel material. The case member 10 is container-shaped with one open side and has a flange portion 10a provided around the opening and a mating surface 10b formed on the flange portion 10a. The case member 10 is attached to the gearbox case 5 from the side (left side in FIG. 17 ) via the flange portion 10a, and has a ceiling wall 12 having a ceiling surface 12a facing the interior 11, a side wall 13 on which the electronic components 2 are provided, and a side wall 14 connected to the side wall 13 and positioned opposite the opening of the case member 10.

[0079] The gearbox case 5 houses gear mechanisms such as a reduction mechanism and a differential mechanism. The gearbox case 5 has a flange portion 5a provided around the opening and a mating surface 5b formed on the flange portion 5a, and the case member 10 is fastened to the gearbox case 5 with bolts with the mating surfaces 5b, 10b mated. The inside of the case member 10 (interior 11) and the inside of the gearbox case 5 (interior 51) communicate with each other through an opening bordered by the flange portions 5a, 10a.

[0080] Oil OL is stored in the gearbox case 5. After being heated by frictional heat generated by gears of the gear mechanism, etc., the oil OL is stored in the bottom of the gearbox case 5. The oil OL stored in the bottom of the gearbox case 5 constitutes a heat source that warms the interior 11 of the case member 10. The oil OL as a heat source is further stored in the case member 10 through openings bordered by the flange portions 5a, 10a.

[0081] A control valve unit 3 is further housed within the case member 10. The control valve unit 3 is housed within the case member 10 and the gearbox case 5. The control valve unit 3 includes a control valve and oil passages that control the pressure of the oil OL to the hydraulic actuator, and the oil OL stored in the bottom of the gearbox case 5 is supplied to the control valve unit 3 by an oil pump.

[0082] The heat source that heats the inside of the case member 10 may be a heat-generating electronic component or other component. For example, since high-temperature oil OL flows through the control valve unit 3 while the vehicle is running, the control valve unit 3 also becomes a heat source. The heat source may be located at the same height as the electronic component 2 or at a higher position than the electronic component 2. The heat source may be located outside the case member 10, as long as it can heat the inside of the case member 10.

[0083] 17 and 18 , the case member 10 has an inner wall IW on the upper side in the direction of gravity of the electronic component 2 (upper side in FIG. 17 ), and a condensation suppression portion M made of a different material from the case member 10 is attached to the inner wall IW of the case member 10 on the upper side in the direction of gravity of the electronic component 2. The upper side in the direction of gravity is the upper side in the direction of gravity when the case 1 is mounted on a vehicle, and the up-and-down direction in FIG. 17 corresponds to the direction of gravity when the case 1 is mounted on a vehicle. The following description of the direction of gravity and the sides will be given assuming that the case 1 is mounted on a vehicle.

[0084] The condensation suppression portion M is a member capable of suppressing condensation, and is formed of a material that is less prone to condensation than the case member 10, thereby suppressing condensation. The condensation suppression portion M is attached to the ceiling surface 12a that forms the inner wall IW above the electronic component 2 in the direction of gravity, and has a portion that overlaps with the electronic component 2 as viewed in the direction of gravity. The condensation suppression portion M further abuts laterally against the inner surface 13a of the side wall 13 above the electronic component 2 in the direction of gravity, thereby covering the installation portion of the electronic component 2. The condensation suppression portion M is provided to cover the entire electronic component 2 and overlaps with the entire electronic component 2 as viewed in the direction of gravity. Note that, although the condensation suppression portion M has a rectangular parallelepiped shape in this embodiment, it may have other shapes. Furthermore, the condensation suppression portion M may be provided in at least one of the following ways: having a portion that overlaps with the electronic component 2 as viewed in the direction of gravity; abutting against the inner surface 13a of the side wall 13; and overlapping with the entire electronic component 2 as viewed in the direction of gravity.

[0085] In the case 1, the condensation suppression portion M is provided above the electronic component 2 to be protected from water in the direction of gravity, thereby preventing water droplets resulting from condensation from falling onto the electronic component 2. Furthermore, since the condensation suppression portion M is attached to the inner wall IW of the case member 10, the dead space between the inner wall IW of the case member 10 and the electronic component 2 can be effectively utilized, and the overall size of the case 1 does not need to be changed, preventing the overall case 1 from becoming larger in the vertical direction (direction of gravity). Furthermore, since the condensation suppression portion M is provided from a different material from the case member 10, it is possible to suppress condensation without changing the complex structure of the case member 10, such as by doubling the walls of the case member 10.

[0086] The condensation suppression unit M is attached to the inner wall IW of the case member 10. The condensation suppression unit M can be attached to the inner wall IW with an adhesive, for example. The condensation suppression unit M is attached to the ceiling surface 12a that forms the inner wall IW. The condensation suppression unit M may also be attached to the inner surface 13a of the side wall 13 that forms the inner wall IW.

[0087] The condensation suppression unit M is simply attached to the inner wall IW, so there is no need to change the design of the case member 10 in order to attach the condensation suppression unit M to the inner wall IW. In addition, since it is simply attached, installation is simple and there is a high degree of freedom in the installation location.

[0088] The condensation suppression unit M is made of resin. Examples of resin that can be used include PPS resin, nylon resin, phenolic resin, and epoxy resin. For example, if a soft resin is used for the condensation suppression unit M, the condensation suppression unit M can be attached to match the shape (unevenness, etc.) of the attachment surface of the inner wall IW of the case member 10, allowing for a high degree of freedom in the attachment position.

[0089] Resin has a lower thermal conductivity than metal, and the thermal conductivity of the condensation suppression portion M is lower than the thermal conductivity of the case member 10. As a result, when the temperature inside the case member 10 is high and the temperature outside the case member 10 is low, even if the case member 10 is cooled by outside air, the condensation suppression portion M, which has a low thermal conductivity, is less likely to be cooled. This makes it possible to suppress condensation on the surface of the condensation suppression portion M and to prevent water droplets resulting from condensation from falling onto the electronic components 2.

[0090] The thermal conductivity of the condensation suppression portion M may be made lower than the thermal conductivity of the case member 10 by using a material other than resin. In addition to resin, the condensation suppression portion M may be made of, for example, rubber or nonwoven fabric.

[0091] 19 is a diagram showing a modified example of the case 1. The condensation suppression unit M may be attached to the inner wall IW by embedding it. In this example, the condensation suppression unit M is embedded in the ceiling wall 12 while being exposed to the interior 11. For example, the condensation suppression unit M is embedded in the ceiling wall 12 by providing a hole 12b that opens into the ceiling surface 12a in the ceiling wall 12 and installing the condensation suppression unit M in the hole 12b. In this example, the condensation suppression unit M is embedded in the ceiling wall 12 instead of being attached by utilizing dead space within the case member 10.

[0092] Even in this case, condensation can be suppressed by the condensation suppression portion M provided above the electronic component 2 in the direction of gravity. This prevents water droplets resulting from condensation from falling onto the electronic component 2. Furthermore, even in this case, the overall size of the case 1 does not need to be changed, so an increase in the vertical size of the entire case 1 can be suppressed.

[0093] 20 is a diagram illustrating a first modified example of the condensation suppression unit M. The condensation suppression unit M may be attached to the inner wall IW by welding, or may be configured to suppress condensation by utilizing convection, which will be described below.

[0094] In this example, the condensation suppression unit M has an L-shaped cross section and includes a bottom wall W11 and a side wall W12 that stands up from one end (the end on the left side in FIG. 20) of the bottom wall W11 in the width direction (the left-right direction in FIG. 20). The bottom wall W11 has an end E11 opposite the side from which the side wall W12 stands up, and the side wall W12 has an end E12 opposite the side connected to the bottom wall W11.

[0095] The condensation suppression unit M is attached at its ends E11 and E12 to the inner wall IW above the electronic component 2 in the direction of gravity, with the end E11 attached to the inner surface 13a of the side wall 13 and the end E12 attached to the ceiling surface 12a. The bottom wall W11 is disposed opposite the ceiling surface 12a, and the side wall W12 is disposed opposite the inner surface 13a of the side wall 13. The condensation suppression unit M is formed from a metal material different from that of the case member 10, and the end E11 is welded to the inner surface 13a of the side wall 13 and the end E12 is welded to the ceiling surface 12a. In other words, in this example, the condensation suppression unit M is attached to the case member 10 by joining dissimilar materials.

[0096] A gap C1 is formed between the condensation suppression unit M and the inner wall IW. The gap C1 is formed as a space surrounded by the bottom wall W11, the side wall W12, the ceiling wall 12, and the side wall 13, and is formed as a gap between the bottom wall W11 and the ceiling surface 12a, and also as a gap between the side wall W12 and the inner surface 13a of the side wall 13. The gap C1 is formed in a rectangular parallelepiped shape and extends along the ceiling surface 12a. In this example, condensation suppression by the condensation suppression unit M utilizes convection as described below.

[0097] 21 is an explanatory diagram of condensation suppression by the condensation suppression unit M of the first modified example. When the temperature inside the case member 10 is high and the outside air is low, the warm air inside the case member 10 is cooled by the low-temperature outside air, and the amount of saturated water vapor in the air inside the case member 10 decreases. As a result, the moisture that the air can no longer contain condenses, causing condensation. Therefore, inside the case member 10, which is heated by the oil OL as a heat source, condensation, indicated by the black circles, can occur on the inner surface of the wall of the case member 10 that comes into contact with the cold outside air.

[0098] On the other hand, when the inside of the case member 10 is heated by the oil OL and a temperature difference occurs within the case member 10, the warm air expands and becomes lighter due to a decrease in density, so it rises (solid arrow), and conversely, the cold air descends (dashed arrow), so convection occurs within the case member 10.

[0099] In the first modification, because there is a gap C1 between the condensation suppression unit M and the inner wall IW, the heated air inside the case member 10 passes through the gap C1 by convection, warming the inside of the gap C1. This makes it possible to suppress condensation on the surface of the condensation suppression unit M. In this way, the condensation suppression unit M may be configured to suppress condensation by utilizing convection.

[0100] The warm air that is heated and rises inside the case member 10 collides with the ceiling surface 12 a and then diffuses and moves in all directions along the ceiling surface 12 a.

[0101] In contrast, the gap C1 communicates with the interior 11 outside the condensation suppression unit M in the direction opposite to the direction of convection generated in the interior 11. This allows warm air to be efficiently sent to the gap C1. Furthermore, the gap C1 extends along the direction of the convection. This allows the gap C1 to extend in a direction that does not interfere with the flow of convection, making it easier to guide warm air into the gap C1.

[0102] The gap C1 communicates with the interior 11 outside the condensation suppression unit M toward the center of the oil OL (see FIG. 17 ) serving as a heat source when viewed in the direction of gravity. This allows warm air that is heated by the oil OL from near the oil OL serving as a heat source, rises, hits the ceiling surface 12a, and moves by diffusing in all directions to be guided into the gap C1. The center of the oil OL serving as a heat source can be the center of a storage unit that is provided in the case member 10 and stores the oil OL.

[0103] The gap C1 communicates with the interior 11 outside the condensation suppression unit M in a direction different from the direction facing the side wall 13 on which the electronic components 2 are provided. The gap C1 communicates with the interior 11 outside the condensation suppression unit M toward the side wall 13, and also communicates with the interior 11 outside the condensation suppression unit M toward the opening whose edge is the flange portion 10a (see FIG. 17 ). In this way, it is possible to prevent the convection flow that passes through the gap C1 from being obstructed by the electronic components 2, and the flow of warm air through the gap C1 is improved.

[0104] Figure 21 is a diagram showing a second modified example of the condensation suppression unit M. In this example, the condensation suppression unit M has a U-shaped cross section and includes a bottom wall W21 and side walls W22 and W23 that stand upright from both ends of the bottom wall W21 in the width direction (left-right direction in Figure 21). The side walls W22 and W23 have ends E21 and E22 on the opposite side from the side connected to the bottom wall W21, and extend approximately parallel to each other from the bottom wall W21.

[0105] The condensation suppression unit M is attached to the ceiling surface 12a at its ends E21 and E22. The bottom wall W21 faces the ceiling surface 12a, and the side wall W22 faces the side wall 14 (see FIGS. 17 and 18 ). The condensation suppression unit M is made of the same metal material as the case member 10, and is welded to the ceiling surface 12a at its ends E21 and E22.

[0106] A gap C2 is formed between the condensation suppression portion M and the inner wall IW. The gap C2 is formed as a space surrounded by the bottom wall W21, the side walls W22 and W23, and the ceiling wall 12, and is formed between the bottom wall W21 and the ceiling surface 12a. The gap C2 is formed in a rectangular parallelepiped shape.

[0107] The warm air that is heated inside the case member 10 and hits the ceiling surface 12a near the gap C2 outside the condensation suppression unit M passes through the gap C2 by convection, thereby heating the inside of the gap C2. Therefore, even with this type of condensation suppression unit M, it is possible to suppress condensation on the surface of the condensation suppression unit M.

[0108] The gap C2 may be composed of multiple gaps, such as gaps in a laminated structure or honeycomb structure. The same applies to the gap C1 (see FIG. 21). The gap C2 may be formed so as to extend in a direction different from that shown in FIG. 22 when viewed in the direction of gravity.

[0109] 20 and 22, the condensation suppression portion M may be formed of a resin or other material with a lower thermal conductivity than the case member 10. This synergistically suppresses condensation on the surface of the condensation suppression portion M by the effect of warming the inside of the condensation suppression portion M through convection and the effect of making the condensation suppression portion M less likely to be cooled by outside air. In addition, including such a case, the condensation suppression portion M in the first and second modifications may be attached to the inner wall IW.

[0110] Next, the main effects of Case 1 will be described.

[0111] (1-2) The case 1 has an electronic component 2 and a case member 10 that houses the electronic component 2 inside 11, and a condensation suppression part M made of a material different from the case member 10 is attached to the inner wall IW of the case member 10 above the electronic component 2 in the direction of gravity.

[0112] In a case where the inside is warmer than the outside, the air inside the case can be cooled by the ceiling, causing condensation. However, if you try to suppress the effects of cold outside air by installing an insulating layer across the entire ceiling, the entire case will become larger vertically.

[0113] In contrast, with this configuration, the condensation suppression unit M is provided above the electronic component 2, in the direction of gravity, to protect it from water, thereby preventing water droplets resulting from condensation from falling onto the electronic component 2. Furthermore, since the condensation suppression unit M is attached to the inner wall IW of the case member 10, the dead space between the inner wall IW of the case member 10 and the electronic component 2 can be effectively utilized, which eliminates the need to change the overall size of the case 1 and prevents the case 1 from becoming too large in the vertical direction.

[0114] (18) The condensation suppression unit M is attached to the inner wall IW. With this configuration, condensation can be suppressed simply by attaching the condensation suppression unit M to the inner wall IW of the case member 10, eliminating the need to change the design of the case member 10. In addition, installation is simple and allows for a high degree of freedom in the installation location.

[0115] (19) The thermal conductivity of the condensation suppression portion M is lower than the thermal conductivity of the case member 10. With this configuration, when the temperature inside the case member 10 is high and the temperature outside the case member 10 is low, even if the case member 10 is cooled by outside air, the condensation suppression portion M, which has low thermal conductivity, is less likely to be cooled. This makes it possible to suppress condensation on the surface of the condensation suppression portion M and to prevent water droplets resulting from condensation from falling onto the electronic components 2.

[0116] (20) The condensation suppression unit M is made of resin, and the case member 10 is made of metal. With this configuration, when the temperature inside the case member 10 is high and the temperature outside the case member 10 is low, even if the case member 10 is cooled by outside air, the condensation suppression unit M, which has low thermal conductivity, is not easily cooled. This makes it possible to suppress condensation on the surface of the condensation suppression unit M and to prevent water droplets resulting from condensation from falling onto the electronic component 2. Furthermore, for example, if a soft resin is used for the condensation suppression unit M, it is possible to attach the condensation suppression unit M to match the shape (unevenness, etc.) of the mounting surface of the inner wall IW of the case member 10, which provides a high degree of freedom in the mounting position.

[0117] (21) Gaps C1 and C2 may be provided between the condensation suppression portion M and the inner wall IW. With this configuration, heated air inside the case member 10 passes through the gaps C1 and C2 by convection, and the inside of the gaps C1 and C2 is heated, making it possible to suppress condensation on the surface of the condensation suppression portion M.

[0118] According to the first and second embodiments described above, the following advantageous effects are achieved.

[0119] (1) The case 1 has a case member 10 that houses an electronic component 2 in an interior 11, and the interior 11 is heated by a heat source. The case 1 has at least one of an insulating section (i.e., a space S formed by a through hole H) that is provided on an inner wall IW above the electronic component 2 in the direction of gravity and has a space S that communicates with the interior 11, and a condensation suppression section M made of a material different from the case member 10.

[0120] With this configuration, when a temperature difference occurs within the case member 10, warm air expands and becomes lighter due to a decrease in density, causing it to rise, while cold air descends. This generates convection within the case member 10, allowing the warm air within the case member 10 to pass through the insulation section having the space S communicating with the interior through convection. Therefore, providing the insulation section makes it difficult for the cold outside to be transmitted to the bottom surface of the insulation section (the inner wall surface of the case). Furthermore, by warming the space S with the warm air within the case member 10, a temperature drop on the bottom surface of the insulation section is suppressed, thereby preventing condensation on the bottom surface of the insulation section. Furthermore, since the through-holes H are provided above the electronic components 2 to be protected from water in the direction of gravity, water droplets resulting from condensation are prevented from falling onto the electronic components 2, eliminating the need to provide a sealed insulation layer across the entire ceiling. Furthermore, providing the condensation suppression section M above the electronic components 2 to be protected from water in the direction of gravity prevents water droplets resulting from condensation from falling onto the electronic components 2. Furthermore, because the condensation suppression unit M is attached to the inner wall IW of the case member 10, it is possible to effectively utilize the dead space between the inner wall IW of the case member 10 and the electronic component 2, without changing the overall size of the case 1. This prevents the overall case 1 from becoming larger in the vertical direction.

[0121] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0122] Furthermore, the above-described embodiments and modifications can be combined as appropriate.

[0123] 1: Case 2: Electronic component 5: Gearbox case (separate case) 10: Case member 11: Interior 13: Side wall B: Protrusion B1: Bottom C: Gap C1: Gap C2: Gap D: Recess H: Through hole H1: First opening H2: Second opening IW: Inner wall M: Condensation suppression part OL: Oil (heat source) S: Space (heat insulation part) T1: Thickness W1: Side wall W2: Side wall W20: Wall part

Claims

1. A case having a case member that houses electronic components inside, the interior of which is heated by a heat source, comprising at least one of a heat insulating section provided on an inner wall above the electronic components in the direction of gravity and having a space that communicates with the interior, and a condensation suppression section made of a material different from the case member.

2. A case according to claim 1, wherein the space is defined by an inner wall of a through hole.

3. A case according to claim 2, wherein the heat insulating portion is formed by a protrusion provided on the surface of the inner wall of the electronic component and protruding toward the inside of the case member, and the through hole is provided in the protrusion.

4. A case according to claim 2 or 3, wherein the through-hole has an opening that opens in a direction opposite to the direction of convection generated inside the case.

5. A case according to claim 4, wherein the through-holes extend along the direction of the convection current.

6. A case according to claim 2 or 3, wherein the through-hole has an opening that opens toward the center of the heat source when viewed in the direction of gravity.

7. A case according to claim 2, wherein the through hole is round in a cross section perpendicular to the direction in which the through hole extends.

8. A case according to claim 3, wherein the through hole is square in a cross section perpendicular to the direction in which the through hole extends.

9. A case as claimed in claim 3, wherein the through-hole has an opening in the side wall of the protruding portion that opens to the interior, and the opening opens in a direction different from the direction facing the side wall on which the electronic component is provided.

10. A case according to claim 3, wherein a separate case is joined to the case member, and the through-hole has an opening that opens toward the separate case.

11. A case as claimed in claim 3, wherein a separate case is joined to the case member, an oil reservoir is provided in an internal space defined by the joined separate case, and the through-hole has an opening that opens towards the centre of the oil reservoir when viewed in the direction of gravity.

12. A case according to claim 3, wherein the through hole extends along the ceiling of the case member.

13. A case according to claim 2, wherein the thickness of the portion forming the bottom wall of the through hole is thinner than the opening height of the through hole.

14. A case according to claim 3, wherein the bottom surface of the protrusion has a shape that follows the shape of the bottom of the cross section of the through hole perpendicular to the direction in which the through hole extends.

15. A case according to claim 1, wherein the space is defined by an inner wall of a recess.

16. A case according to claim 15, wherein the heat insulating portion is formed by a protrusion provided on the surface of the inner wall of the electronic component and protruding toward the interior, and the recess is provided in the protrusion.

17. A case as described in claim 1, wherein the case member has a wall portion provided on the inner wall above the electronic component in the direction of gravity, and the heat insulating portion has the space defined by the gap between the wall portion and the surface of the inner wall.

18. A case according to claim 1, wherein the condensation suppression section is attached to the inner wall.

19. A case according to claim 1 or 18, wherein the thermal conductivity of the condensation suppression portion is lower than the thermal conductivity of the case member.

20. A case according to claim 19, wherein the condensation suppression portion is made of resin and the case member is made of metal.

21. A case according to claim 1, wherein there is a gap between the condensation suppression portion and the inner wall.

Images