JP5017003B2 - Metal closed switchgear - Google Patents

Description

  The present invention relates to a metal closed type switchgear in which a ventilation port for ventilating a box is arranged on the front side.

  Conventionally, a metal closed type switchgear in which an electrical device such as a circuit breaker is housed in a box body is provided with a ventilation port for intake near the lower part on the front side in order to suppress the temperature rise due to heat generation of the electrical device, There is a ventilation port for exhausting. A so-called natural ventilation type metal closed switchgear is known (see, for example, Patent Document 1).

On the other hand, when the stored electrical equipment causes a short-circuit accident, an arc is generated and the pressure rises, and the high-temperature gas may be ejected from the ventilation port on the front side of the box. Maintenance personnel such as maintenance inspections may be present on the front side, and it is necessary to prevent high temperature gas from being ejected. However, the ventilation port is necessary for suppressing the temperature rise and cannot be sealed off. In addition, the ejection of hot gas from the ceiling vent is allowed.
JP 2007-28740 A (second page, FIG. 3)

  In the conventional metal closed type switchgear described above, there is a possibility that hot gas may be ejected from the front side ventilation port provided to suppress the temperature rise in the box when an arc is generated. For this reason, what can prevent the ejection of a high temperature gas reliably was desired.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a metal closed type switchgear that prevents hot gas from being ejected from a vent on the front side of a box when an arc is generated.

In order to achieve the above object, a metal closed switchgear according to the present invention is provided with a box for storing electrical equipment, a front side ventilation opening provided on the front side of the box, and an inner side of the box. a protective plate for closing the front ventilation openings which are provided in said box body side of the front ventilation openings Rutotomoni, a first locking member which is bent in Les-shape outwardly, said first together is locked in the bent portion of the locking member, provided in the protective plate, and a second locking member which is bent in Les-shape on the inside, is fixed to the inside of the box body, the A stud that movably passes through the four corners of the protective plate, and a spring that is provided on the outer periphery of the stud and is biased to open the protective plate .

  According to the present invention, since the protective plate that is moved and locked by the pressure increase in the box is provided at the front side ventilation port, the protective plate closes the front side ventilation port when an arc occurs, and the pressure is This state is maintained until the temperature is lowered, and the ejection of hot gas from the front side ventilation port can be reliably prevented.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a metal closed switchgear according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing the configuration of a metal closed switchgear according to a first embodiment of the present invention, and FIG. 2 is an open state of a front side vent of the metal closed switchgear according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing a closed state of the front side ventilation opening of the metal closed switchgear according to the first embodiment of the present invention, and FIG. 4 is a metal closure according to the first embodiment of the present invention. It is a figure explaining the pressure characteristic when an arc generate | occur | produces in the box body of a type | mold switchgear.

  As shown in FIG. 1, a control device 2 and a circuit breaker 3 are arranged from the ceiling on the front side on the left side in the box 1 for storing electrical equipment, and a front side ventilation port 4 for intake air on the floor side. Is provided. On the rear side on the right side of the figure, a bus 5 connected to one main circuit of the circuit breaker 3 and a current transformer 6 connected to the other main circuit are arranged. The main circuit of the current transformer 6 is connected to a ground switch 7 on one side and a power receiving cable 8 on the other side. Note that an exhaust ceiling side ventilation port 9 is provided at the ceiling of the box 1.

  Here, four rod-shaped studs 10 are fixed to the front side ventilation port 4 at the four corners inside the box 1. The four corners of a plate-shaped protective plate 11 having a size for closing the front side ventilation port 4 are movably penetrated through the stud 10. The protective plate 11 has mechanical strength and heat resistance associated with an increase in pressure when an arc is generated. A nut 12 is fixed to the end of the stud 10 so that the protective plate 11 does not fall off.

  Further, a spring 13 is provided on the outer periphery of the stud 10 so as to separate the protective plate 11 from the front side ventilation opening 4 in the normal state so as to open the cover. And the 1st latching metal fitting 14 is fixed to the box body 1 side, and the 2nd latching metal fitting 15 latched by the 1st latching metal fitting 14 is provided in the guard plate 11 side. For example, the front end of the first locking member 14 is bent outwardly in a letter shape, and the tip of the second locking member 15 is bent inwardly in a letter shape. If the outer dimension of the tip of the second locking fitting 15 is made slightly larger, the bent portions are fitted together, and the protection plate 11 can be locked.

  Even if a convex protrusion is provided on one side and a concave fitting portion into which a convex part is fitted is provided on the other side, the second locking metal 15 can be locked to the first locking metal 14. it can. These are defined as first and second locking members.

  Next, the operation of the protection plate 11 will be described with reference to FIGS.

  The open state of the front side ventilation port 4 is shown in FIG. A first locking fitting 14 bent in a letter shape is provided on the outer side of the box body 1, and a second locking fitting 15 bent in a letter shape on the inner side is provided on the protection plate 11 side. It has been. The protection plate 11 is separated from the front side ventilation port 4 by the spring force of the spring 13, and ventilation is performed.

  When an arc occurs due to a short circuit accident or the like, as shown in FIG. 3, the pressure in the box body 1 rises, and the protective plate 11 moves to the front vent 4 side as indicated by an arrow. Then, the front-side ventilation port 4 is closed with the protective plate 11, and the second locking member 15 is fitted into the first locking member 14, so that the protective plate 11 is locked. Thereby, the high temperature gas by an arc stops spouting out of the box 1 from the front side ventilation port 4. This is the closed state of the front side ventilation port 4.

  FIG. 4 shows the pressure characteristics of the hot gas. The pressure rises rapidly from the time of arc generation at time t0, reaches a maximum at t1, and starts to descend until the arc disappears and the pressure decreases. . In such pressure characteristics, the protection plate 11 moves to the front side ventilation port 4 side from t0 to t1, and closes and locks the front side ventilation port 4. For this reason, the protection plate 11 maintains the closed state of the front side ventilation port 4 until t2 when the pressure decreases.

  Here, if the protection plate 11 is not locked to the box body 1 side, the inside of the box body 1 has a decompression characteristic from t1 when the pressure is maximum to t2 when the pressure is reduced. The protective plate 11 may move to leave the front-side ventilation port 4. In the protection plate 11 in such a state, there is a possibility that high temperature gas is ejected from the front side ventilation port 4. However, since the protection plate 11 is locked, the high temperature gas can be reliably prevented from being ejected outside the box 1. In the ceiling side ventilation port 9, ejection of high temperature gas is permitted.

  If the protective plate 11 is made of a heat-resistant insulator made of, for example, a fluororesin, a barrier effect is produced, so that the insulation characteristics between the ground can be improved. If a position switch for detecting the position of the protection plate 11 in the normal state is provided, it is possible to detect that the ventilation is normal.

  According to the metal closed type switchgear of the first embodiment, the first locking member 14 is provided on the box body 1 side, the second locking member 15 is provided on the protection plate 11, and the protection plate is provided when an arc is generated. 11, the front side ventilation port 4 is closed and this state is maintained until the pressure decreases, so that it is possible to reliably prevent the hot gas from being ejected from the front side ventilation port 4.

  Next, a metal closed switchgear according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing the open state of the front side vent of the metal closed switchgear according to the second embodiment of the present invention, and FIG. 6 is a front view of the metal closed switchgear according to the second embodiment of the present invention. It is sectional drawing which shows the closed state of a side ventilation port. The second embodiment is different from the first embodiment in the configuration of the protective plate. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Moreover, since the structure of the metal closed type switchgear is the same as that of Example 1, description is abbreviate | omitted.

  As shown in FIG. 5, an arc-shaped stud 20 is fixed to the front ventilation opening 4 at the upper part inside the box 1. The stud 20 is provided with a plate-shaped protective plate 11 that is movably penetrated on one side. The other side of the protection plate 11 is fixed to a hinge 21 fixed to the box 1 on the lower side of the front side ventilation port 4.

  In addition, the stud 20 is provided with a spring 13 that keeps the protective plate 11 away from the front-side ventilation opening 4 in a normal state and opens the lid. A nut 12 is fixed to the end of the stud 20 so that the protective plate 11 does not fall off. In the opened state, the protective plate 11 is inclined at about 45 degrees toward the box 1 and ventilation is performed.

  A third locking fitting 22 is fixed on the box body 1 side, and a fourth locking fitting 23 to be locked to the third locking fitting 22 is provided on the upper part of the protection plate 11. Yes. For example, if the third locking bracket 22 is bent outwardly in a letter shape and the fourth locking bracket 23 is bent inwardly in a letter shape, the third locking bracket 22 is The fourth locking fitting 23 can be locked. These are defined as first and second locking members.

  Next, the operation of the protection plate 11 will be described with reference to FIG.

  In the normal state, the upper part of the front side ventilation opening 4 is opened by the spring force of the protection plate 11 by the spring 13, and ventilation is performed. When an arc occurs due to a short circuit accident or the like, as shown in FIG. 6, the pressure in the box body 1 rises, and the protection plate 11 rotates as shown by the arrow with the hinge 21 as a fulcrum. The side ventilation opening 4 is closed by the protection plate 11, and the fourth locking fitting 23 is fitted into the third locking fitting 22 to lock the protection plate 11. Thereby, the front side ventilation port 4 will be in a closed state, and the ejection of the hot gas to the exterior of the box 1 by an arc is prevented.

  According to the metal closed switchgear of the second embodiment, the same effect as that of the first embodiment can be obtained.

The side view which shows the structure of the metal closed type switchgear which concerns on Example 1 of this invention. Sectional drawing which shows the cover open state of the front side ventilation port of the metal closed type switchgear which concerns on Example 1 of this invention. Sectional drawing which shows the closed state of the front side ventilation port of the metal closed type switchgear which concerns on Example 1 of this invention. The figure explaining the pressure characteristic when an arc generate | occur | produces in the box of the metal closed type switchgear which concerns on Example 1 of this invention. Sectional drawing which shows the cover open state of the front side ventilation opening of the metal closed type switchgear which concerns on Example 2 of this invention. FIG. 6 is a cross-sectional view showing a closed state of the front side ventilation opening of the metal closed switchgear according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Box body 2 Control apparatus 3 Circuit breaker 4 Front side ventilation port 5 Bus 6 Current transformer 7 Grounding switch 8 Cable 9 Ceiling side ventilation port 10, 20 Stud 11 Guard plate 12 Nut 13 Spring 14 1st latching metal 15 Second locking bracket 21 Hinge 22 Third locking bracket 23 Fourth locking bracket

Claims (3)

A box for storing electrical equipment;
A front side ventilation opening provided on the front side of the box,
A protective plate for closing the front-side ventilation opening provided inside the box,
Rutotomoni provided on the box body side of the front vents, a first locking member which is bent in Les-shape on the outside,
With locked in the bent portion of the first engagement member, provided in the protective plate, and the second locking member which is bent Les-shape and the inside,
A stud that is fixed inside the box and that movably penetrates the four corners of the protective plate,
A spring provided on the outer periphery of the stud and biased to open the protection plate;
A metal closed type switchgear characterized by comprising: A box for storing electrical equipment;
A front side ventilation opening provided on the front side of the box,
A protective plate for closing the front-side ventilation opening provided inside the box,
A rotatable hinge with one side fixed to the lower part of the protective plate and the other side fixed to the box,
A first locking member which is provided at the upper part of the box side of the front side ventilation opening and is bent outwardly in a letter shape;
A second locking member that is locked to the bent portion of the first locking member, is provided at an upper portion of the protection plate, and is bent in a letter shape inside;
A stud that is fixed to the inside of the box and movably penetrates the upper part of the protective plate;
A spring provided on the outer periphery of the stud and biased to open the protection plate;
A metal closed type switchgear characterized by comprising: 3. The metal closed switchgear according to claim 1, wherein the protective plate is a heat-resistant insulator .

Images