Electrical device, electrical device housing, and aircraft

Abstract

Provided are: an electrical device capable of maintaining a dry state of gas in a housing while withstanding an expansion force of the gas in the housing; an electrical device housing; and an aircraft. The electrical device comprises: an electrical component; a housing 5 that stores the electrical component; a cover 6 that is connected to the housing 5 and covers an opening of the housing 5; and a sealing part 11 that seals between a connection surface of the housing 5 and a connection surface of the cover 6 facing each other. A dry gas is sealed inside the housing 5 and the cover 6. The sealing part 11 comprises a sealing material 12 having elasticity, and a sealing material 13 which is disposed outside the sealing material 12 and has moisture resistance.

Description

Electrical equipment, electrical equipment housings, and aircraft

[0001] The present invention relates to an electric device, a housing for the electric device, and an aircraft.

[0002] Patent Document 1 discloses a power conversion device, which is a type of electrical equipment, that is installed on an aircraft (mobile body). This power conversion device includes electrical components such as power semiconductor modules and a housing that houses the electrical components. The housing is filled with dry gas. This prevents condensation inside the housing due to environmental changes and prevents failure and deterioration of the electrical components.

[0003] Patent No. 6878712

[0004] Although not described in Patent Document 1, the housing of an electrical device generally has a divided structure. The housing includes a housing that houses electrical components and a cover that is connected to the housing and covers the opening of the housing. Therefore, it is necessary to provide a sealant between the connecting surfaces of the housing and the cover that face each other.

[0005] Here, if dry gas is sealed in the housing as described in Patent Document 1, a moisture-proof sealant must be provided. However, a moisture-proof sealant alone may not be enough to maintain the dry state of the gas inside the housing. To explain this in more detail, for example, when a mobile object moves to a higher altitude, the pressure outside the housing of the electrical equipment mounted on the mobile object decreases. This increases the expansion force of the gas due to the difference between the pressure inside and outside the housing, and this expansion force of the gas acts on the sealant. Because a moisture-proof sealant does not have elasticity, it may not be able to withstand the expansion force of the gas and may be damaged. As a result, it may not be possible to maintain the dry state of the gas inside the housing.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and one of its objectives is to maintain a dry state of the gas inside the housing of the electrical equipment while withstanding the expansion force of the gas inside the housing of the electrical equipment.

[0007] In order to solve the above problems, the present invention applies the configurations described in the claims. The present invention includes a plurality of means for solving the above problems, and one example thereof is an electrical device comprising: an electrical component, a housing for storing the electrical component, a cover connected to the housing and covering an opening of the housing, and a sealing part for sealing between opposing connection surfaces of the housing and the cover, wherein a dry gas is sealed inside the housing and the cover, the sealing part comprises a first sealant having elasticity and a second sealant arranged outside the first sealant and having moisture-proof properties.

[0008] According to the present invention, it is possible to withstand the expansion force of the gas inside the housing of the electrical device and maintain the gas inside the housing of the electrical device in a dry state.

[0009] Fig. 1 is a cross-sectional view showing the structure of a power conversion device according to one embodiment of the present invention. Fig. 2 is a cross-sectional view showing the structure of a power conversion device according to a first modified example of the present invention. Fig. 3 is a partially enlarged cross-sectional view showing the structure of a housing of a power conversion device according to a second modified example of the present invention. Fig. 4 is a partially enlarged cross-sectional view showing the structure of a housing of a power conversion device according to a third modified example of the present invention. Fig. 5 is a schematic view showing the structure of an aircraft according to a fourth modified example of the present invention. Fig. 6 is a schematic view showing the structure of an aircraft according to a fifth modified example of the present invention. Fig. 7 is a schematic view showing the structure of an aircraft according to a sixth modified example of the present invention.

[0010] An embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing the structure of a power conversion device in this embodiment.

[0011] The power conversion device 100 of this embodiment is mounted on a moving body (not shown) such as an aircraft, transportation equipment, or construction machinery, and is equipped with a plurality of electrical components (in other words, components that function when electricity is applied) and a housing 1 that stores the plurality of electrical components.

[0012] The electrical components constitute an electrical circuit and include, for example, a plurality of power conversion elements 2, a plurality of capacitors 3, and a substrate 4. The power conversion elements 2 are, for example, insulated gate bipolar transistors (IGBTs). The capacitors 3 are, for example, electrolytic capacitors, ceramic capacitors, film capacitors, or hybrid capacitors, and are used for smoothing and filtering.

[0013] In addition, if a pressure valve (not shown) is provided to prevent damage to the capacitor 3, it is preferable to set the pressure inside the housing 1 to a slightly negative pressure compared to atmospheric pressure when the power conversion device 100 is stopped in order to prevent the pressure valve from malfunctioning.

[0014] The enclosure 1 includes a housing 5 that houses the above-mentioned electrical components, and a cover 6 that is connected to the housing 5 and covers the opening of the housing 5. The housing 5 and the cover 6 are made of, for example, metal. This makes it difficult for noise current caused by lightning to flow into the electrical components even if a lightning strike occurs, preventing malfunction of the electrical components.

[0015] The housing 5 has a cooling passage 7 as a cooling means through which a refrigerant (specifically, water, mineral oil, Fluorinert, vegetable oil, or the like) flows. The refrigerant in the cooling passage 7 cools the housing 5 and also cools the electrical components through the housing 5. The cooling means may be a heat pipe or forced air cooling.

[0016] One of the flange 8 of the housing 5 and the flange 9 of the cover 6 (in this embodiment, the flange 9 of the cover 6) has a plurality of through holes formed therein, into which a plurality of bolts 10 are respectively inserted, and the other (in this embodiment, the flange 8 of the housing 5) has a plurality of threaded holes into which the plurality of bolts 10 are respectively threaded. The plurality of bolts 10 are inserted into the through holes and threaded into the threaded holes, thereby connecting the flange 8 of the housing 5 and the flange 9 of the cover 6. This brings the connecting surface (upper surface) of the housing 5 and the connecting surface (lower surface) of the cover 6 close to each other and facing each other.

[0017] The housing 1 is filled with dry gas. The dry gas is, for example, dry air, nitrogen, argon, carbon dioxide, or nitrogen dioxide, and is a gas with a water vapor pressure lower than the saturated water vapor pressure when the temperature drops to a predetermined value (for example, -70°C) due to an environmental change. This prevents condensation inside the housing 1 due to environmental changes, and prevents breakdowns and deterioration of electrical components.

[0018] The dry gas may contain oxygen as a gas with high electron attachment, and the oxygen concentration may be higher than that of the atmosphere (21%). Alternatively, the dry gas may contain carbon dioxide, sulfur hexafluoride, carbon monoxide, or a halogen-based gas as a gas with high electron attachment. This may suppress discharge in the electrical components and improve insulation.

[0019] The housing 1 includes a sealing portion 11 that seals between the connecting surface of the housing 5 and the connecting surface of the cover 6. The sealing portion 11 includes a stretchable sealing material 12 (first sealing material) and a moisture-proof sealing material 13 (second sealing material) that is disposed outside the sealing material 12. Note that the stretchable sealing material 12 is waterproof but not moisture-proof, and the moisture-proof sealing material 13 is not stretchable.

[0020] The sealant 12 is filled in a groove 14 formed on the connecting surface of the housing 5 (located inside the bolt 10 in this embodiment). Considering that the connecting surface of the cover 6 may be rough, the sealant 12 is preferably made of a material and with a shape that is more easily deformed three-dimensionally than an O-ring. The sealant 12 may be made of, for example, synthetic rubber, elastomer, polymer gel, mortar, or clay. Specific examples of the sealant 12 that can be used to shorten the curing time include two-component curing or ultraviolet curing silicone rubber, or two-component curing or ultraviolet curing urethane.

[0021] The sealant 13 is attached to the outside of the housing 5 and the cover 6 so as to straddle the boundary between the connecting surfaces of the housing 5 and the cover 6. The sealant 13 is, for example, a metal film, and a specific example of such a film may be an aluminum vapor-deposited film. Alternatively, the sealant 13 is, for example, asphalt roofing. Alternatively, the sealant 13 is, for example, a resin film, and a specific example of such a film may be a film made of polyvinyl, polypropylene, polyethylene, nylon, or polyvinylidene chloride. Alternatively, the sealant 13 is, for example, a resin, and a specific example of such a resin may be a two-component curing or ultraviolet curing epoxy resin, or may be polyvinyl, polypropylene, polyethylene, nylon, or polyvinylidene chloride.

[0022] The effects of the sealing portion 11 of the housing 1 of this embodiment will be described.

[0023] For example, when a mobile object moves to a higher altitude, the pressure outside the housing 1 of the power conversion device 100 mounted on the mobile object decreases. This increases the expansion force of the gas due to the difference in pressure between the inside and outside of the housing 1. This gas expansion force acts on the inner sealing material 12, but not on the outer sealing material 13, of the sealing materials 12 and 13 that make up the sealing portion 11. The sealing material 12 is stretchable and can withstand the expansion force of the gas. However, the sealing material 12 is waterproof but not moisture-proof. On the other hand, the sealing material 13 is not stretchable but moisture-proof, and therefore can maintain the dry state of the gas inside the housing 1. Therefore, the sealing portion 11 of the housing 1 of this embodiment can withstand the expansion force of the gas inside the housing 1 while maintaining the dry state of the gas inside the housing 1. As a result, failure and deterioration of electrical components can be prevented.

[0024] In the above embodiment, the seal 12 is described as having a shape and material that is more easily deformed three-dimensionally than an O-ring, but this is not limiting. That is, if the connection surface of the cover 6 is not rough, the seal 12A may be an O-ring, as in the modified example shown in FIG. 2 .

[0025] In the above embodiment, the sealant 12 is disposed in the groove 14 formed on the connecting surface of the housing 5, and the sealant 13 is attached to the outside of the housing 5 and the cover 6. However, this is not limited to this. For example, as shown in a modified example in FIG. 3, the sealant 13A may be disposed in another groove 16 formed on the connecting surface 15 of the housing 5 so as to be positioned outside the groove 14 (outside the bolt 10 in this modified example). Also, as shown in a modified example in FIG. 4, the sealant 12 may be disposed in a groove 14A formed on the connecting surface 17 of the cover 6 (so as to be positioned inside the bolt 10 in this modified example). The sealant 13A may be disposed in another groove 16A formed on the connecting surface 17 of the cover 6 so as to be positioned outside the groove 14 or 14A (for example, outside the bolt 10). The sealant 13A may be, for example, a resin. Specific examples of the resin include two-component curing or ultraviolet curing epoxy resin, polyvinyl, polypropylene, polyethylene, nylon, and polyvinylidene chloride. In the above-described modified example, the same effects as those of the above-described embodiment can be obtained.

[0026] In the above embodiment, the mobile body equipped with the power conversion device 100 was described as an aircraft, transportation equipment, construction machinery, or the like. Specific examples thereof will now be described with reference to FIGS. 5 to 7. A multi-person aircraft 101A shown in FIG. 5 or a small-person aircraft 101B shown in FIG. 6 includes multiple drive units 102A. A small-person aircraft 101C shown in FIG. 7 includes multiple drive units 102A and 102B. The drive unit 102A includes a power conversion device 100 that converts power from a secondary battery (not shown), an electric motor 103 that rotates using the power converted by the power conversion device 100, and a propulsion fan (not shown) that is rotated by the electric motor 103 and generates forward thrust. The drive unit 102B includes a power conversion unit 100 that converts power from a secondary battery (not shown), an electric motor 103 that rotates using the power converted by the power conversion unit 100, and a propulsion fan (not shown) that is rotated by the electric motor 103 and generates upward thrust.

[0027] Although the above description has been given taking as an example a case where the present invention is applied to the power conversion device 100, which is one type of electrical equipment, the present invention is not limited to this and may be applied to other electrical equipment.

[0028] REFERENCE SIGNS LIST 1 casing 2 power conversion element 3 capacitor 4 substrate 5 housing 6 cover 11 sealing portion 12, 12A sealing material (first sealing material) 13, 13A sealing material (second sealing material) 14, 14A groove 15 connection surface 16, 16A other groove 17 connection surface 100 power conversion device (electrical equipment) 101A, 101B, 101C aircraft

Claims

1. An electrical device comprising an electrical component, a housing for storing the electrical component, a cover connected to the housing and covering an opening of the housing, and a sealing portion for sealing between a connection surface of the housing and a connection surface of the cover facing each other, in the electrical device in which a dry gas is enclosed inside the housing and the cover, the sealing portion includes a first sealing material having elasticity and a second sealing material disposed outside the first sealing material and having moisture-proof property.

2. The electrical device according to claim 1, wherein the first sealing material is disposed in a groove formed on the connection surface of the housing or the connection surface of the cover.

3. The electrical device according to claim 2, wherein the second sealing material is attached to the outside of the housing and the cover so as to straddle between the connection surface of the housing and the connection surface of the cover.

4. The electrical device according to claim 2, wherein the second sealing material is disposed in another groove formed so as to be located outside the groove on the connection surface of the housing or the connection surface of the cover.

5. The electrical device according to claim 2, wherein the first sealing material is synthetic rubber, elastomer, polymer gel, mortar, or clay.

6. The electrical device according to claim 3, wherein the second sealing material is a metal film, a resin film, or asphalt roofing.

7. The electrical device according to claim 3 or 4, wherein the second sealing material is epoxy resin, polyvinyl, polypropylene, polyethylene, nylon, or polyvinylidene chloride.

8. In a housing of an electrical device comprising an electrical component, a housing for storing the electrical component, a cover connected to the housing and covering an opening of the housing, and a sealing portion for sealing between a connection surface of the housing and a connection surface of the cover facing each other, in the electrical device in which a dry gas is enclosed inside the housing and the cover, the sealing portion includes a first sealing material having elasticity and a second sealing material disposed outside the first sealing material and having moisture-proof property.

9. In the housing of the electrical apparatus according to claim 8, the first sealing material is disposed in a groove formed at the connection surface of the housing or the connection surface of the cover. A housing of an electrical apparatus, characterized in that.

10. In the housing of the electrical apparatus according to claim 9, the second sealing material is adhered to the outside of the housing and the cover so as to straddle between the connection surface of the housing and the connection surface of the cover. A housing of an electrical apparatus, characterized in that.

11. In the housing of the electrical apparatus according to claim 9, the second sealing material is disposed in another groove formed so as to be located outside the groove at the connection surface of the housing or the connection surface of the cover. A housing of an electrical apparatus, characterized in that.

12. In the housing of the electrical apparatus according to claim 9, the first sealing material is synthetic rubber, an elastomer, a polymer gel, mortar, or clay. A housing of an electrical apparatus, characterized in that.

13. In the housing of the electrical apparatus according to claim 10, the second sealing material is a metal film, a resin film, or asphalt roofing. A housing of an electrical apparatus, characterized in that.

14. In the housing of the electrical apparatus according to claim 10 or 11, the second sealing material is an epoxy resin, polyvinyl, polypropylene, polyethylene, nylon, or polyvinylidene chloride. A housing of an electrical apparatus, characterized in that.

15. An aircraft equipped with the electrical apparatus according to claim 1.

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