JP3385900B2 - Circuit breaker box equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box device in which a circuit breaker is housed and used.

[0002]

2. Description of the Related Art Circuit breakers are not installed centrally on a switchboard or the like, but when installed independently at a construction site or around machinery, they are installed in a box device for safety reasons. FIG. 4 is a view showing the outer appearance of the box device of this circuit breaker. 5 is an external perspective view of the joint portion of the cover and the case of the conventional box device. FIG. 6 is a view showing an external appearance of a conventional box device after an internal circuit breaker has interrupted a large current. In the figure, 1 is a box device, 2 is a circuit breaker housed in the box device 1, and 3 is a distribution line.
11 is a case of the box-shaped box device 1 with one surface opened,
Reference numeral 12 is a cover of the box device that covers the opening of the case 11, and is provided with side edges 12a that are engaged with the outside of the four side surfaces of the case 11 in an overlapping manner. 13 is a clamp member fixed to the side edge 12a, and 14 is a case 11 at a position facing the clamp member 13 when the cover 11 is covered with the case 11.
No. 4 is an arm member fixed to the four side faces of the above, and is provided with a female screw. Reference numeral 15 is a tightening screw that is screwed to the female screw of the arm member 14 via the clamp member 13 to connect the case 11 and the cover 12.

In such a state that the circuit breaker 2 is housed in the box device and the case 11 and the cover 12 are connected by the tightening screw 15, the circuit breaker 2 cuts off a large current due to a short circuit accident or the like. At that time, due to the pressure of the energy (hot gas) released at the time of interruption,
As shown in FIG. 6, the portion that is weak against the increase in the internal pressure is deformed most.

[0004]

In the conventional box device for a circuit breaker as described above, the internal pressure of the energy (hot gas) released when the circuit breaker 2 breaks a large current is increased. , The stress is concentrated on the center line of the cover 12, and the clamp member 13 and the arm member 14 are prying open at an angle as shown in FIG. 6, and the tightening screw 15 is deformed. Therefore, when the circuit breaker 2 is removed from the box device after the break, the rotation of the fastening screw 15 is hindered, and the circuit breaker 2 cannot be taken out.

The present invention has been made to solve the above problems. Even if the case 11 and the cover 12 are deformed due to an increase in internal pressure when the circuit breaker 2 cuts off a large current,
The purpose is to reduce the deformation stress on the clamp member 13 and the arm member 14 and prevent the deformation of the tightening screw 15. Further, the cover 12 is prevented from being permanently deformed due to the release of the cutoff gas from the circuit breaker 2 so that the cover 12 does not need to be replaced.

[0006]

A box device for a circuit breaker according to a first aspect of the present invention is a connection for screwing a case and a cover between a side edge extending at a right angle from an upper surface of the cover and a side surface of the case. A member is provided, and a kerf for weakening the side is provided between the corner of the cover and the position where the joining member is fixed to the side of the cover.

According to a second aspect of the present invention, there is provided a box device for a circuit breaker, wherein a second cut is provided on a side adjacent to a side provided with the cut groove, at a position at a distance substantially equal to a corner of the cut groove and the cover. A groove is provided.

In the box device for a circuit breaker according to claim 3 of the present invention, a plurality of cut grooves are provided between each cut groove and the corner of the cover, and the depth of the cut groove is close to the corner of the cover. It's deepened.

[0009]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1. 1 is a view showing the outer appearance of a box device for a circuit breaker according to a first embodiment of the present invention. Figure 2
FIG. 4 is a diagram showing an external appearance of the box device of the present invention after the internal circuit breaker has interrupted a large current. In the figure, 1
1 to 15 are the same as those described in the conventional device. 16 is a clamp member 1 on the side 12a of the cover 12.
3 is a kerf provided in the vicinity of the fixed portion 3. In this way, the side 12a in the vicinity where the clamp member 13 is fixed is
The kerf 16 which is a fragile portion that makes it easy to deform the cover 12
Since the fragile portion is deformed and the cutoff gas inside is released in response to an increase in internal pressure of the circuit breaker 2 when a large current is cut off, the clamp member 13 and the arm member 14 are not deformed. Further, it is possible to prevent the tightening screw 15 from being deformed.

Reference numeral 17 denotes a side 1 on which the kerf 16 is provided.
It is a second kerf provided on the side 12a different from 2a. The second kerf 17 is provided at a position where the distance from the corner of the cover 12 is substantially equal to the kerf 16 and the second kerf 17, and on the line connecting the kerf 16 and the second kerf 17. Are more fragile than others, and this fragile part mainly deforms due to the increase in internal pressure when the circuit breaker 2 cuts off a large current, releasing the internal cutoff gas and deforming other parts. Reduce.

Embodiment 2. FIG. 3 is a diagram showing the external appearance of the box device according to the second embodiment of the present invention after the internal circuit breaker has performed the large current interruption. In the figure, 11 to
17 is the same as that described in the first embodiment. 16a and 16b are a plurality of kerfs provided between the kerfs 16 and the corners of the cover 12, and the depths of the kerfs are 16b>16a> 16. Further, a plurality of kerfs 17a and 17b are also provided between the second kerfs 17 and the corners of the cover 12, and the depth of the kerfs is 17 as well.
b>17a> 17. Cover kerf depth 1
The larger the angle is, the closer it is to the corner of 2, so that the deformation stress due to the internal pressure is made uniform in each kerf.

As described above, in the structure in which a plurality of cut grooves are provided, the cover 12 is released when the internal cutoff gas is released when the internal circuit breaker cuts off a large current.
Although the kerfs of the corners of the cover 12 are deformed, the kerfs are deformed in a distributed manner in the respective kerfs, so unless the large current is cut off, the material of the cover 12 is not elastically deformed and does not permanently deform. You don't have to replace

[Brief description of drawings]

FIG. 1 is a diagram showing an outer appearance of a box device for a circuit breaker according to a first embodiment of the present invention.

FIG. 2 is a view showing the external appearance of the box device of the present invention after the internal circuit breaker has performed large current interruption.

FIG. 3 is a diagram showing an external appearance of a box device according to a second embodiment of the present invention after an internal circuit breaker has performed large current interruption.

FIG. 4 is a diagram showing an appearance of a box device of a circuit breaker.

FIG. 5 is an external perspective view of a cover and a case of a conventional box device.

FIG. 6 is a diagram showing an external appearance of a conventional box device after an internal circuit breaker has interrupted a large current.

[Explanation of symbols]

2 circuit breaker, 11 case, 12 cover 12a side, 13 clamp member, 14 arm member 15 tightening screw, 16, 17 kerf

─────────────────────────────────────────────────── ───Continued from the front page (56) References Japanese Unexamined Patent Publication No. 2-139813 (JP, A) Actually open 3-77350 (JP, U) Actually open 51-143165 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H01H 9/02 H01H 71/02 H01H 73/06

Claims (3)

(57) [Claims] 1. A box device for a circuit breaker having a circuit breaker housed therein, a case having one surface opened to accommodate the circuit breaker,
A cover that covers the open surface of the case, and a side edge that extends at a right angle from the top surface of the cover and that overlaps the four side surfaces of the case;
A coupling member that is fixed to at least two opposing side surfaces and the side edge and that screw-couples the case and the cover, and the side edge is fragile between the position where the coupling member is fixed to the side edge of the cover and the corner of the cover. A box device for a circuit breaker, which is provided with a kerf that changes the shape. 2. The second kerf is provided on a side adjacent to the side where the kerf is provided, at a position having a distance substantially equal to the corner of the kerf and the cover. Box device for circuit breaker. 3. A plurality of kerfs are provided between each kerf and a corner of the cover, and the depth of the kerf is set to be deeper toward the corner of the cover. Box device for circuit breaker.