EXPLOSION-PROOF HOUSING

Abstract

An explosion-proof housing for a power electronics unit includes a housing pan and a cover that closes the housing pan via a seal, wherein the cover and the housing pan are pressed against each other at two opposing sides formed by edge regions of the cover and the housing pan via a plurality of fasteners that are configured to be released by rotation and that engage in latching structures. The plurality of fasteners are arranged in a central third of the respective sides. The explosion-proof housing can be used, for example, for a photovoltaic inverter.

Claims

1. A housing that is explosion-proof for a power electronics unit, comprising: a housing pan, and a cover that closes the housing pan via a seal, wherein edge regions of the housing pan and cover together form a first pair of opposing sides, and a second pair of opposing sides, wherein the cover and the housing pan are pressed against each other only at one of the first pair or the second pair of opposing sides formed by the edge regions of the cover and the housing pan, via a plurality of fasteners that are configured to be released by rotation and that engage in latching structures, and wherein the plurality of fasteners are arranged in a central third of the respective sides.

2. The housing according to claim 1, wherein on each side precisely one fastener is arranged in a middle of the side.

3. The housing according to claim 1, wherein two fasteners are arranged on at least one side.

4. The housing according to claim 1, wherein the fasteners are arranged releasably from the housing pan, and each of which engage in the latching structure which is arranged in or on the cover and is invisible from the side of the cover facing away from the housing pan.

5. The housing according to claim 4, wherein the latching structures are each arranged on a fastening bar which is fastened to the cover and which deforms in the event of a pressure rise in the housing interior such that a gap between the housing pan and the cover also forms in a region of the fasteners, through which gap the rising pressure can escape.

6. The housing according to claim 1, wherein the fasteners are configured as screws and the latching structures are configured as threads, wherein the screws engage through openings in the housing pan into the threads arranged in or on the cover.

7. The housing according to claim 1, wherein the fasteners are in each case configured as a quarter-turn fastener.

8. The housing according to claim 7, wherein the latching structure comprises a fastening bar, wherein the fastening bar is fastened to the cover at opposite ends and has a retaining cam in a central region for receiving the quarter-turn fastener in a latching manner.

9. The housing according to claim 7, wherein the quarter-turn fastener comprises a visually discernible indicator that shows a latching state of the quarter-turn fastener.

10. The housing according to claim 1, wherein the housing has two further sides that are shorter than the sides in which the fasteners are arranged.

11. The housing according to claim 1, wherein the cover has a structural element on a cover edge that reduces a force required for a bending of the cover along a bending line running between the fasteners, wherein the structural element comprises a notch on the cover edge, an indentation in the cover, or a reduced cover thickness in a region of the bending line.

12. A photovoltaic inverter comprising a housing, wherein the housing comprises: a housing pan, and a cover that closes the housing pan via a seal, wherein edge regions of the housing pan and cover together form a first pair of opposing sides, and a second pair of opposing sides, wherein the cover and the housing pan are pressed against each other only at one of the first pair or the second pair of opposing sides formed by the edge regions of the cover and the housing pan, via a plurality of fasteners that are configured to be released by rotation and that engage in latching structures, and wherein the plurality of fasteners are arranged in a central third of the respective sides.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The disclosure is illustrated below with reference to the drawings, in which:

[0022] FIG. 1 shows an embodiment according to the disclosure of an explosion-proof housing in a front view,

[0023] FIG. 2 shows another embodiment according to the disclosure of an explosion-proof housing in a rear view,

[0024] FIG. 3 shows two detailed views of a fastener of a housing, and

[0025] FIG. 4 shows a cover with structural elements for reducing the forces required for forming a discharge gap.

DETAILED DESCRIPTION

[0026] FIG. 1 shows a first embodiment according to the disclosure of an explosion-proof housing 1 of a power electronics unit. The housing comprises a housing pan 2, in the interior of which the device components are contained, and which is closed by a cover 3. A seal arranged between cover 3 and housing pan 2 prevents dirt and/or liquid from penetrating into the interior of the housing.

[0027] In one embodiment, the cover 3 is pressed against the housing pan 2 by two fasteners 4, the fasteners 4 being arranged centrally on opposite sides 6 of the rectangular housing 1. Further fastening elements with which the cover 2 is held on the housing pan 3 are not provided in the embodiment shown in FIG. 1. The sides on which the fasteners 4 are arranged are here longer than the sides with no fastener.

[0028] In one embodiment, the fasteners 4 can be formed by screws which are accessible from the cover side and engage in a thread in the housing pan 2. However, the screws can also be accessible from the side of the housing pan 2 and engage in threads arranged on or in the cover 3. The latter variant also perm its a design of the fastener 4 that is invisible from the cover side.

[0029] FIG. 2 shows another embodiment according to the disclosure of an explosion-proof housing 1 of a power electronics unit. Here, arranged on at least one side 6 of the housing 1, are two fasteners 4 which are located in the central third 6.2 of the length of the side 6. The adjacent two outer thirds 6.1 and 6.3 have no fasteners 4. Along the concealed side shown opposite the side 6, a single, central fastener or likewise two fasteners can be arranged at positions corresponding to the positions along the side 6.

[0030] As shown in the enlarged detail of FIG. 2, the fastener 4 is designed here as a quarter-turn fastener 8 which is accessible from the side of the housing pan 2. This makes it possible to release the cover 3 from the housing pan 2 with little effort, so that the housing interior is easily accessible for repair purposes, for example.

[0031] FIG. 3 shows in two perspective representations a possible configuration of the individual fasteners as quarter-turn fasteners. The upper illustration in FIG. 3 shows a fastening bar 7, which is screwed to the cover 3 at opposite ends. A retaining cam 5 for a quarter-turn fastener to be inserted therein is arranged in a central region of the fastening bar 7, which is configured to be at a distance from the cover 3 by corresponding shaping. The fastening bar 7 is screwed to the cover 3 via elongated holes, which enable the distance between the central region of the fastening bar 7 and the cover 3 to increase when there is a high tensile force on the retaining cam 5. Furthermore, the cover 3 has a notch 10 directly adjacent to the retaining cam 5, the effect of which will be discussed later.

[0032] In the lower illustration in FIG. 3, a quarter-turn fastener 8 arranged on the housing pan 2 is inserted into the retaining cam 5 of the fastening bar 7 that is fastened to the cover 3. Locking the quarter-turn fastener 8 in the retaining cam 5 causes the cover 3 to be fastened to the housing pan 2.

[0033] FIG. 4 shows an embodiment of a cover 2 of an explosion-proof housing according to the disclosure. Along a direct connecting line between the two individual fasteners 4, the cover 3 has an indentation 11 which can be introduced into the cover 3 during the shaping process. This indentation 11 as a structural element represents a deliberate weakening of the cover 3 in relation to a compressive force acting on the outer regions of the cover 3 from the inside of the housing in the assembled state of the cover 3 on the housing pan 2, as a result of which the cover bends or folds under such a force along a bending line essentially corresponding to the connecting line, and, as a result, even in the case of reduced explosion pressure, already forms a discharge gap between the cover 3 and the housing pan 2.

[0034] Alternatively or additionally, a notch 10 in the cover edge in the intersection region with the bending line and/or a reduced cover thickness in the region of the bending line can also be used as a structural element for a targeted weakening of the cover 3 in relation to bending along the bending line.

[0035] In the case in which two fasteners in each case are arranged on both opposite sides of the housing, and thereby two bending lines, each between the two fasteners assigned to the same outer region, are formed, for each bending line structural elements can be provided for weakening the cover with respect to bending. For those structural elements mentioned identical structural elements or even different structural elements can be provided.