Housing of electrical equipment

Abstract

To provide a technique capable of surely conducting a housing and a cover in an enclosure in which a liquid-state gasket is used for sealing the housing and the cover.SOLUTION: An enclosure comprises: a housing and a cover which have conductivity; and a gasket which has non-conductivity. The housing includes an opening, and a first seating face is provided around the opening. The cover closes the opening of the housing. The gasket is disposed between the first seating face and the cover. The gasket is a liquid-state gasket which has flowability in the beginning but is hardened after coating. A second seating face, a positioning pin protruding from the second seating face and a groove separating the second seating face from the first seating face are provided in the housing. The cover includes a tab extending from a cover main body along with the second seating face. A positioning hole which is fitted to the positioning pin is provided in the tab. The tab is in contact with the second seating face, and the cover and the housing are conducted via the tab.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] The housing of the electrical device has an opening for the user to access the internal electrical components. Usually, the opening is closed by a cover. To seal between the edge of the opening and the cover, a gasket is arranged between the periphery of the opening and the cover. Patent Documents 1 and 2 disclose an inverter in which a gasket is arranged between the opening and the cover. An inverter is a type of electrical device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The housing and the cover are made of conductive materials, while the gasket is often made of non-conductive materials. The housing is often used as the electrical ground of the internal electrical components. If the housing and the cover are not electrically connected, there is a possibility of a potential difference occurring between the housing and the cover. The potential difference between the housing and the cover can cause electromagnetic noise to be radiated through the housing (or electromagnetic noise to enter the housing).

[0005] Typically, a cover is secured to the housing with bolts. Electrical conductivity is established between the cover and the housing when they are in contact around the bolts. However, liquid gaskets are sometimes used to seal the gap between the cover and the housing. Liquid gaskets are sealing materials that are fluid in their initial state and harden after being applied around the housing by drying, ultraviolet light, or heat. When liquid gaskets are used, they may spread to the area around the bolts while they are still fluid, potentially impairing electrical conductivity between the cover and the housing around the bolts. This specification provides a technique for ensuring reliable electrical conductivity between the housing and the cover in an enclosure (enclosure of electrical equipment) where a liquid gasket is used to seal the gap between the housing and the cover. [Means for solving the problem]

[0006] The housing disclosed herein comprises a conductive housing and cover, and a non-conductive gasket. The housing has an opening and a first seating surface is provided around the opening. The cover closes the opening of the housing. The gasket is positioned between the first seating surface and the cover. The housing has a second seating surface located adjacent to the first seating surface, a positioning pin protruding from the second seating surface, and a groove separating the second seating surface from the first seating surface. The cover has a cover body and a tab. The tab extends from the cover body along the second seating surface. The tab is provided with a positioning hole for engaging with the positioning pin. The gasket is a liquid gasket that is fluid before being applied to the first seating surface and hardens after application. The tab is in contact with the second seating surface, and the cover and housing are electrically connected through the tab.

[0007] In the housing disclosed herein, the cover is electrically connected to the housing via a tab that contacts a second seating surface. The second seating surface is separated from the first seating surface by a groove. Even if liquid gasket applied to the first seating surface spreads around the first seating surface, any excess gasket falls into the groove and does not reach the second seating surface. In other words, excess gasket does not obstruct electrical connection between the tab and the housing. That is, the cover is reliably electrically connected to the housing.

[0008] The height of the second seating surface should be greater than or equal to the surface height of the gasket. When the cover is attached to the housing, the tab and the second seating surface will make secure contact.

[0009] Details of the technology disclosed herein and further improvements are described in the following "Modes for Carrying Out the Invention". [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of the housing of the embodiment. [Figure 2] A perspective view of the housing of the embodiment (with the cover removed). [Figure 3] This is a cross-sectional view of the housing along the line III-III in Figure 1. [Modes for carrying out the invention]

[0011] The housing 2 of the embodiment will be described with reference to the drawings. Figure 1 shows a perspective view of housing 2. Figure 2 shows a perspective view of housing 2 with the cover 20 removed. Figure 3 shows a cross-sectional view of housing 2 along line III-III in Figure 1. Figures 1-3 show only a part of housing 2. Electrical components are housed inside housing 2. Housing 2 is a housing for electrical equipment, specifically, for example, an inverter housing.

[0012] The main components of enclosure 2 are a housing 10 that houses electrical components and a cover 20. An opening 11 is provided on one side of the housing 10. The opening 11 is provided for maintenance staff to check the condition of the internal electrical components or to replace them. The maintenance opening 11 is sometimes called an access hole.

[0013] The cover 20 closes the opening 11. The cover 20 is fixed to the housing 10 with bolts 40. The area occupied by the opening 11 is part of one surface of the housing 10, and the housing 10 is provided with a cover base 12 that surrounds the opening 11. The cover 20 is attached to the cover base 12. The cover base 12 is provided with two fixing bases 12a that protrude laterally, and bolt holes 12b are provided on the top surface of each fixing base 12a.

[0014] The cover 20 is made from a single metal plate. The cover 20 comprises a cover body 21 that closes the opening 11, and fixing tabs 23 and positioning tabs 22 that extend from the edge of the cover body 21. The fixing tab 23 extends along the top surface of the fixing base 12a. The fixing tab 23 is provided with a bolt hole 23a through which a bolt 40 passes. The bolt 40 passes through the bolt hole 23a of the fixing tab 23 and is fixed to the bolt hole 12b of the fixing base 12a. The top surface of the cover base 12 will be referred to as the first seating surface 12s below.

[0015] The housing 10 is provided with a pin base 13 next to the cover base 12. Both the cover base 12 and the pin base 13 are located on one surface of the housing 10. The top surface of the pin base 13 is referred to as the second seating surface 13s. A positioning pin 14 is provided on the second seating surface 13s. The positioning pin 14 protrudes from the second seating surface 13s.

[0016] A groove 15 is provided between the cover base 12 and the pin base 13. In other words, a groove 15 is provided between the first seat surface 12s and the second seat surface 13s. The groove 15 separates the second seat surface 13s from the first seat surface 12s.

[0017] The positioning tab 22 extends from the edge of the cover body 21 along the second seating surface 13s. In other words, the positioning tab 22 faces the second seating surface 13s. The positioning tab 22 is provided with a positioning hole 22a that engages with the positioning pin 14.

[0018] When attaching the cover 20 to the housing 10, by passing the positioning pin 14 through the positioning hole 22a, the appropriate relative position of the cover 20 with respect to the cover pedestal 12 is determined. Note that the housing 10 has a plurality of positioning pins, and the cover 20 is provided with a plurality of positioning tabs corresponding to each positioning pin. However, in the figure, only one positioning pin 14 and one positioning tab 22 are shown, and the illustration of the other positioning pins and positioning tabs is omitted.

[0019] A gasket 30 is sandwiched between the first seating surface 12s and the cover body 21. In FIG. 2, for the sake of understanding, the surface of the gasket 30 is shaded gray. 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 solidifies after application by drying or ultraviolet irradiation or heating. Such a gasket is called a liquid gasket. A typical example of a liquid gasket is Formed In Place Gasket (commonly known as FIPG). FIPG is a liquid gasket using a foamed foam. After sandwiching the initial FIPG having fluidity and bringing two surfaces (sealing surfaces) into close contact, the FIPG cures by heating or ultraviolet irradiation or absorption of moisture in the air.

[0020] In order to bring the two sealing surfaces into close contact while the FIPG has fluidity, excess FIPG may overflow from the sealing surface. In FIG. 2, a state where the excess gasket 30a has spread to around the bolt hole 12b of the fixed base 12a is depicted.

[0021] Although not shown in FIG. 2, there is a possibility that excess gasket spreads outside the first seating surface 12s over the entire area of the first seating surface 12s surrounding the opening 11. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1, and FIG. 3 depicts excess gaskets 30b, 30c overflowing from the first seating surface 12s.

[0022] As shown in FIG. 3, the second seating surface 13s is separated from the first seating surface 12s by the groove 15. The excess gasket 30c that overflows 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.

[0023] Incidentally, the housing 10 and the cover 20 are made of conductive materials. If the potential of the housing 10 and the potential of the cover 20 are different, there is a risk that the electromagnetic noise emitted by the electrical components inside the housing 10 will leak outside the housing 2. Alternatively, there is a risk that the electromagnetic noise outside the housing 2 will reach the internal electrical components. Therefore, it is desirable that the housing 10 and the cover 20 have the same potential. On the other hand, the gasket 30 has non-conductivity. 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) are not in contact. The bolt 40 contacts both the housing 10 and the cover 20, and there is a possibility that the housing 10 and the cover 20 are electrically connected through the bolt 40. However, the bolt 40 may be made of a material having a relatively large electrical resistance or may be coated with a material having a relatively large electrical resistance. In such a case, a potential difference may remain between the housing 10 and the cover 20 through the bolt 40.

[0024] On the other hand, as described above, the excess 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 (see FIG. 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 both are at the same potential. 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 surely electrically connected.

[0025] Furthermore, as shown in Figure 3, the height H of the second seating surface 13s (the height from the lowest point of the housing 10 to the second seating surface 13s) is the same as the height of the surface of the gasket 30 (gasket surface 30s). This structure also contributes to reliable contact between the second seating surface 13s and the positioning tab 22 (cover 20). Note that the height H of the second seating surface 13s may be the same as or higher than the height of the gasket surface 30s. If 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 base 13 and deformed. The positioning tab 22 makes firm contact with the second seating surface 13s, and reliable electrical contact is maintained between the housing 10 and the cover 20.

[0026] The fact that the height H of the second seat surface 13s is the same as or higher than the height of the gasket surface 30s is equivalent to the height of the second seat surface 13s being higher than the height of the first seat surface 12s.

[0027] The following points concern the technology described in the embodiment. The housing may have multiple positioning pins (positioning base and second seating surface). The cover may have multiple positioning holes corresponding to each positioning pin. Multiple positioning pins may be provided on one pin base. Each of the multiple positioning pins may be provided on each of the multiple pin bases. If the housing has multiple pin bases, it is sufficient that a groove is provided between the seating surface (second seating surface) and the first seating surface of at least one pin base.

[0028] The cover may have holes for cables to pass through or connectors.

[0029] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of Symbols]

[0030] 2: Enclosure 10: Housing 11: Opening 12: Cover base 12a: Fixing base 12b, 23a: Bolt holes 12s: First seating surface 13: Pin base 13s: Second seating surface 14: Positioning pin 15: Groove 20: Cover 21: Cover body 22: Positioning tab 22a: Positioning hole 23: Fixing tab 30: Gasket 30a, 30b, 30c: Excess gasket 30s: Gasket surface 40: Bolt

Claims

1. It is the casing of electrical equipment, A housing that is conductive, has an opening, and has a first seating surface around the opening, It is conductive, and has a cover that closes the opening, A gasket which is non-conductive and is disposed between the first seating surface and the cover, It is equipped with, The housing is provided with a second seating surface located next to the first seating surface, a positioning pin protruding from the second seating surface, and a groove separating the second seating surface from the first seating surface. The cover has a tab that extends from the cover body along the second seating surface and has a positioning hole that fits into the positioning pin. The gasket is a liquid gasket that is fluid before being applied to the first seating surface and hardens after application. The tab is in contact with the second seating surface, and the cover and the housing are electrically connected via the tab. Cabinet.

2. The housing 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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