Frame body of electrical equipment

Abstract

The invention provides a housing of an electrical device. A housing disclosed in the present specification is provided with: a conductive case and a cover; and a gasket having a non-conductive property. The shell is provided with an opening, and a first seat surface is arranged around the opening. The cover closes the opening of the housing. The gasket is disposed between the first seat surface and the cover. The gasket is a liquid gasket that initially has flowability but cures after coating. The housing is provided with a second seat surface, a positioning pin protruding from the second seat surface, and a groove separating the second seat surface from the first seat surface. The cover has a tab extending from the cover body along the second seating surface. The protruding sheet is provided with a positioning hole which is embedded with the positioning pin. The tab is in contact with the second seat surface, and the cover and the housing are conducted through the tab.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a housing of an electrical device. Background Art

[0002] The outer shell of the housing of an electrical device has an opening for a user to operate internal electrical components. Usually, the opening is closed by a cover. In order to seal between the edge of the opening and the cover, a gasket is arranged between the periphery of the opening and the cover. Inverter devices in which a gasket is arranged between an opening and a cover are disclosed in JP-A-2005-327991 and JP-A-2020-078971. An inverter is a kind of electrical device. Summary of the Invention

[0003] The outer shell and the cover are made of conductive materials, but the gasket is often made of non-conductive materials. The outer shell is often used as the electrical ground (earthing wire) of internal electrical components. If the outer shell and the cover are not electrically connected, a potential difference may be generated between the outer shell and the cover. The potential difference between the outer shell and the cover may cause electromagnetic noise to radiate through the housing (or electromagnetic noise to enter the housing).

[0004] Usually, the cover is fixed to the outer shell by bolts. If the cover and the outer shell are in contact around the bolts, the two are electrically connected. On the other hand, a liquid gasket is sometimes used for sealing between the cover and the outer shell. A liquid gasket is a sealing material that has fluidity in its initial state and cures by drying or ultraviolet rays or heat after being applied around the outer shell. If a liquid gasket is used, the liquid gasket may spread around the bolts during the period when it has fluidity, impairing the electrical connection between the cover and the outer shell around the bolts. This specification provides a technology for reliably electrically connecting the outer shell and the cover in a housing (housing of an electrical device) that uses a liquid gasket for sealing between the outer shell and the cover.

[0005] The housing disclosed in this specification includes: a conductive outer shell and a cover; and a non-conductive gasket.

[0006] The outer shell has an opening, and a first seating surface is provided around the opening. The cover closes the opening of the outer shell.

[0007] The gasket is arranged between the first seating surface and the cover.

[0008] A second seating surface, a positioning pin protruding from the second seating surface, and a groove separating the second seating surface from the first seating surface are provided on the outer shell.

[0009] The cover has a cover body and a tab. The tab extends along the second seating surface from the cover body. A positioning hole that fits with the positioning pin is provided on the tab.

[0010] The gasket is a liquid gasket that has fluidity before being applied to the first seating surface and cures after application.

[0011] The tab contacts the second seating surface, and the cover and the housing are electrically connected via the tab.

[0012] In the housing disclosed in this specification, the cover is electrically connected to the housing via a tab that contacts the second seating surface. The second seating surface is separated from the first seating surface by a groove. Even if the liquid gasket applied to the first seating surface spreads around the first seating surface, the remaining gasket will fall into the groove and thus will not reach the second seating surface. That is, the remaining gasket does not interfere with the electrical connection between the tab and the housing. That is, the cover and the housing are reliably electrically connected.

[0013] The height of the second seating surface can be above the surface height of the gasket. When the cover is installed on the housing, the tab reliably contacts the second seating surface.

[0014] Details of the technology disclosed in this specification and further improvements are described in the following "Detailed Description of the Embodiments". BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the drawings, in which like reference numerals denote like components, and in which:

[0016] Figure 1 is a perspective view of the housing of the embodiment;

[0017] Figure 2 is a perspective view of the housing of the embodiment (with the cover removed);

[0018] Figure 3 is along Figure 1 a cross-sectional view of the housing taken along line III-III of DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The housing 2 of the embodiment will be described with reference to the drawings. Figure 1 shows a perspective view of the housing 2. Figure 2 shows a perspective view of the housing 2 with the cover 20 removed. Figure 3 shows a cross-sectional view of the housing 2 taken along line III-III of Figure 1 In Figure 1 - Figure 3 only a part of the housing 2 is shown. Electrical components are housed inside the housing 2. The housing 2 is a housing of an electrical device, and specifically, for example, a housing of an inverter.

[0020] The main components of the housing 2 are the outer shell 10 for accommodating electrical components and the cover 20. An opening 11 is provided on one surface of the outer shell 10. The opening 11 is provided for maintenance personnel to confirm the status of the internal electrical components or replace the electrical components. The opening 11 for maintenance is sometimes called an access hole.

[0021] The cover 20 closes the opening 11. The cover 20 is fixed to the outer shell 10 by bolts 40. The area occupied by the opening 11 is a part of one surface of the outer shell 10, and a cover pedestal 12 is provided on the outer shell 10 in a manner surrounding the opening 11. The cover 20 is mounted on the cover pedestal 12. Two fixing pedestals 12a protruding laterally are provided on the cover pedestal 12, and bolt holes 12b are provided on the top surfaces of the respective fixing pedestals 12a.

[0022] The cover 20 is made of a single metal plate. The cover 20 includes a cover body 21 for closing the opening 11, fixing tabs 23 extending from the edge of the cover body 21, and positioning tabs 22. The fixing tabs 23 extend along the top surface of the fixing pedestal 12a. Bolt holes 23a for passing the bolts 40 are provided in the fixing tabs 23. The bolts 40 pass through the bolt holes 23a of the fixing tabs 23 and are fixed to the bolt holes 12b of the fixing pedestal 12a. Hereinafter, the top surface of the cover pedestal 12 is referred to as the first pedestal surface 12s.

[0023] On the outer shell 10, a pin pedestal 13 is provided beside the cover pedestal 12. Both the cover pedestal 12 and the pin pedestal 13 are provided on one surface of the outer shell 10. The top surface of the pin pedestal 13 is referred to as the second pedestal surface 13s. A positioning pin 14 is provided on the second pedestal surface 13s. The positioning pin 14 protrudes from the second pedestal surface 13s.

[0024] A groove 15 is provided between the cover pedestal 12 and the pin pedestal 13. In other words, a groove 15 is provided between the first pedestal surface 12s and the second pedestal surface 13s. The groove 15 separates the second pedestal surface 13s from the first pedestal surface 12s.

[0025] The positioning tab 22 extends from the edge of the cover body 21 along the second pedestal surface 13s. In other words, the positioning tab 22 faces the second pedestal surface 13s. A positioning hole 22a for engaging with the positioning pin 14 is provided in the positioning tab 22.

[0026] When the cover 20 is installed on the outer shell 10, by passing the positioning hole 22a through the positioning pin 14, the proper relative position of the cover 20 with respect to the cover pedestal 12 is determined. In addition, the outer shell 10 includes a plurality of positioning pins, and the cover 20 includes a plurality of positioning tabs corresponding to the respective positioning pins. However, in the figure, only one positioning pin 14 and one positioning tab 22 are shown, and other positioning pins and positioning tabs are omitted from the illustration.

[0027] The gasket 30 is sandwiched between the first pedestal surface 12s and the cover body 21. Figure 2In the figure, for the sake of better understanding, a gray hatching is applied to the surface of the gasket 30. The gasket 30 seals between the first seating surface 12s and the cover 20. In other words, the gasket 30 seals around the opening 11. The gasket 30 has fluidity before being applied to the first seating surface 12s and cures by drying or ultraviolet irradiation or heating after being applied. Such a gasket is called a liquid gasket. A representative example of a liquid gasket is a Formed In Place Gasket (FIPG for short). FIPG is a liquid gasket using a foamed foam. After two surfaces (sealing surfaces) are pressed against each other with the initial FIPG having fluidity in between, the FIPG cures by heating or ultraviolet irradiation or absorption of moisture in the air.

[0028] Since the two sealing surfaces need to be pressed against each other while the FIPG has fluidity, sometimes the remaining FIPG may overflow from the sealing surfaces. In Figure 2 the situation where the remaining gasket 30a spreads around the bolt hole 12b of the fixed table 12a is depicted.

[0029] Although not shown in Figure 2 it is possible that the remaining gasket spreads outside the first seating surface 12s over the entire area of the first seating surface 12s surrounding the opening 11. Figure 3 is a cross-sectional view along the III-III line of Figure 1 and in Figure 3 the remaining gaskets 30b and 30c overflowing from the first seating surface 12s are depicted.

[0030] As Figure 3 shown, the second seating surface 13s is separated from the first seating surface 12s by the groove 15. The remaining gasket 30c overflowing from between the cover body 21 and the first seating surface 12s falls into the groove 15 and thus does not reach the second seating surface 13s.

[0031] In addition, the housing 10 and the cover 20 are made of conductive materials. If the potential of the housing 10 is different from that of the cover 20, the electromagnetic noise emitted by the electrical components inside the housing 10 may leak outside the housing 2. Or, the electromagnetic noise outside the housing 2 may reach the internal electrical components. Therefore, it is preferable that the housing 10 and the cover 20 have the same potential. On the other hand, the gasket 30 is non-conductive. Since the non-conductive gasket 30 is sandwiched between the cover body 21 and the first seating surface 12s, the cover body 21 and the first seating surface 12s (housing 10) do not contact each other. The bolt 40 contacts both the housing 10 and the cover 20, and the housing 10 and the cover 20 may be electrically connected through the bolt 40. However, the bolt 40 is sometimes made of a material having a relatively large resistance or coated with a material having a relatively large resistance. In such a case, if electrical connection is made through the bolt 40, a potential difference may remain between the housing 10 and the cover 20.

[0032] On the other hand, as described above, the remaining gasket falls into the groove 15 and thus does not reach the second seating surface 13s. Therefore, the positioning tab 22 contacts the second seating surface 13s (refer to Figure 3 ). The positioning tab 22 is made of the same conductive material as the cover body 21. Therefore, the cover 20 is electrically connected to the housing 10 through the positioning tab 22, and the two become equipotential. By providing the groove 15 between the first seating surface 12s and the second seating surface 13s, the housing 10 and the cover 20 are reliably electrically connected.

[0033] In addition, as Figure 3 shown, the height H of the second seating surface 13s (the height from the lowest position of the housing 10 to the second seating surface 13s) is the same as the height of the surface of the gasket 30 (the gasket surface 30s). This structure also contributes to the reliable contact between the second seating surface 13s and the positioning tab 22 (the cover 20). In addition, the height H of the second seating surface 13s can be the same as or higher than the height of the gasket surface 30s. When the height H of the second seating surface 13s is higher than the gasket surface 30s, the positioning tab 22 is pressed against the pin pedestal 13 and deformed. The positioning tab 22 is firmly in contact with the second seating surface 13s, and the housing 10 and the cover 20 maintain reliable electrical connection.

[0034] The height H of the second seating surface 13s being the same as or higher than the height of the gasket surface 30s is equivalent to the height of the second seating surface 13s being higher than the height of the first seating surface 12s.

[0035] Points to note regarding the technology described in the embodiments are described. The housing may also include a plurality of positioning pins (positioning pedestals and second seating surfaces). The cover may include a plurality of positioning holes corresponding to the respective positioning pins. The plurality of positioning pins may also be provided on one pin pedestal. The plurality of positioning pins may also be provided respectively on each of the plurality of pin pedestals. When the housing includes a plurality of pin pedestals, it is sufficient to provide a groove between the seating surface (second seating surface) of at least one pin pedestal and the first seating surface.

[0036] A hole or a connector for passing a cable may also be provided on the cover.

[0037] As described above, specific examples of the present invention have been described in detail, but these are merely illustrative and do not limit the claims. The technology described in the claims includes technologies obtained by various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility alone or through various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the technology illustrated in this specification or the drawings can achieve multiple purposes simultaneously, and has technical utility by achieving one of the purposes itself.

Claims

1. A frame of an electrical device, wherein: have: A housing having conductivity, an opening, and a first seat surface disposed around the opening; a cover, the cover being conductive and blocking the opening; as well as a sealing gasket, the sealing gasket having non-conductivity and arranged between the first seat surface and the cover, The housing is provided with a second seat surface located beside the first seat surface, a positioning pin protruding from the second seat surface, and a groove separating the second seat surface from the first seat surface. The cover has a convex piece, which extends from the cover body along the second seat surface and is provided with a positioning hole engaged with the positioning pin. The sealing gasket is a liquid sealing gasket which has fluidity before being applied to the first seat surface and solidifies after being applied. The protruding piece contacts the second seat surface, and the cover and the housing are in conduction with each other via the protruding piece.

2. The housing of the electric device according to claim 1, wherein: The height of the second seat surface is greater than or equal to the height of the surface of the gasket.

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