JPH0212669Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention releases the pressure inside the case of a gas switch, etc. to the outside in order to prevent the risk of explosion of the switch due to an abnormal pressure rise inside the case. Relating to a device for

[Conventional technology]

A gas switch is installed inside the case to extinguish the arc when the contact opens and to maintain insulation properties.
It is filled with gas such as SF ₆ gas.

In this type of switch, if the internal pressure rises above a certain level, the switch case will explode if the structure remains as it is, which is dangerous. This prevents the damage from spreading to the entire switch. This is the pressure relief plate.

[Problem that the invention attempts to solve]

The pressure relief plate must be completely sealed to maintain airtightness inside the switch case, but if water, salt, dust, etc. enter this seal from the outside, it will cause deterioration of the sealing member and impair the airtightness. Because of this risk, a dust seal is also required to prevent the infiltration of these contaminants, and it is necessary to perform double sealing.

As for the conventional seal structure, Utility Model 48-29313
There is a type that installs a single gasket between the mounting seat and the pressure relief plate as described in the publication, but it is necessary to maintain the compression ratio of the gasket at a constant value and to prevent the airtight seal from being exposed to the outside by using a dust seal. No consideration was given to preventing deterioration due to infiltrating foreign substances, and there was a problem in that the seal became incomplete due to aging.

The present invention aims to solve these problems and provide a pressure relief device that has a high sealing effect and can maintain the sealing effect over time.

[Means for solving problems]

The present invention arranges an O-ring, an O-ring spacer, and a dust seal outer circumferential packing sequentially from the inside around the opening of the side plate of the switch, with a slight interval as necessary, and at least the O-ring and A pressure relief plate having a flange that straddles and abuts the O-ring spacer is stacked, and a flat dust seal packing is placed over the O-ring, the O-ring spacer, the pressure relief plate flange, and the dust seal outer circumferential packing, and these are combined into a pressure relief plate. It has a sealing structure that is sandwiched between the side plate and the side plate by a holding plate, a concave groove is formed in the opening periphery of the side plate for fixing an O-ring, and a hole is passed through by a bolt installed in the side plate. is provided on the O-ring spacer, the flange of the pressure relief plate, the dust seal flat packing, and the pressure relief plate holding plate.

〔Example〕

Hereinafter, the present invention will be specifically explained based on embodiments shown in the drawings.

FIG. 1 is an exploded perspective view of an embodiment of the present invention, FIG. 2 is a sectional view, and FIG. 3 is an enlarged sectional view.

In the figure, 1 is a switch case, 2 is a side plate, 3 is an O-ring, 4 is an O-ring spacer, 5 is a pressure relief plate, 6 is a dust seal outer periphery packing, 7 is a dust seal flat packing, 8 is a pressure relief plate holding plate, 9, 10 11 is a positioning piece, 12 is a screw seal packing, 13 is a seal washer, 14 is a washer, 15 is a tightening nut, 16 is a short and long tightening bolt installed in the side plate 2.
2 is a spacer, 17 is a protection plate, 18 is a spring washer, 19 is a tightening nut, 20 is a reinforcing plate fixed to the inside of the case of the side plate 2, and 21 in FIG. Therefore, it is a cutting blade that breaks the pressure release plate when it is inverted and expanded outward from the case.

For example, a circular opening 2a is provided in the side plate 2 of the switch case 1, and the periphery 2b of the opening is connected to the pressure relief plate 5.
Make it rounded to avoid scratches.

A concave groove 2c is formed on the outside of the opening 2a of the side plate 2 so that the O-ring packing 3 is accommodated in a fixed position.

On the outer surface of the side plate 2, an O-ring 3, an O-ring spacer 4, and a dust seal outer periphery packing 6 are sequentially arranged from the inside around the opening 2a of the side plate 2 at a slight interval as necessary.
Although it is desirable to minimize the spacing between each component in order to make the whole component smaller, a certain amount of spacing is provided between each component, taking into consideration the regulatory margin and the size of the bulge when the packing is compressed.

The O-ring spacer 4 has an appropriate width, and bolts 9,
Place 10. The O-ring spacer 4 has large-diameter holes 4a at positions corresponding to the bolts 9 and 10 in order to avoid the raised part of the bolt insertion part, and positioning pieces 11 are fitted in at least two places to determine the fitting position. do. It is also possible to fit the positioning piece 11 into all the holes 4a.

The flange 5a of the pressure relief plate 5 is connected to these O-rings 3, O-rings 3,
The ring spacer 4 and the positioning piece 11 are straddled and abutted, and from above, the dust seal flat packing 7 and the pressure relief plate holding plate 8 are stacked, and the flange 5a of the pressure relief plate 5 and the dust seal outer circumferential packing 6 are straddled and abutted. Then, the screw seal packing 12, seal washer 13, and washer 14 are fitted onto the bolts 9 and 10, and tightened with the tightening nut 15.

In this case, the flange portion 5a of the pressure relief plate 5 may straddle and abut a part or all of the dust seal outer circumferential packing 6.

In this way, the O-ring 3, the screw seal packing 9, and the dust seal outer circumferential packing 6 are attached to the side plate 2.
and the pressure relief plate 5, and are appropriately compressed.

After the above tightening is completed, attach the protective plate 17 to the longer bolt 10 via the spacer 16, and then tighten the spring washer 18 and nut 1.
Tighten and fix with step 9.

The thickness of the O-ring spacer 4 is set so that the compression rate of the O-ring 3 is set to a predetermined value, and the compressive force of the dust seal outer circumferential packing 6 is determined at the same time by the thickness of the O-ring spacer 4.

The screw seal gasket 12 is tightly fitted onto the bolts 9 and 10, and a seal washer 13 is fitted so as to surround the outer diameter of the screw seal gasket 12. Furthermore, a washer 14 is fitted so as to abut the screw seal gasket 12 and the seal washer 13. are fitted and tightened with a tightening nut 15,
By this tightening, the thread seal packing 12 is compressed at the same time as the other packings, thereby sealing the threaded portion. The thickness of the seal washer 13 is thinner than that of the screw seal packing 12, and the inner diameter of the seal washer 13 is slightly larger than the outer diameter of the screw seal packing 12 to allow for expansion during tightening.

In order to maintain sealing properties over a long period of time, O-rings and packings have their compressibility adjusted by taking into consideration environmental influences, such as hardness due to temperature changes, speed of shape recovery, degree of permanent deformation, and aging or deterioration of the material. The compression dimension is regulated by the O-ring spacer 4 and the compression rate is kept within the specified range.
This makes it possible to guarantee long-term sealing properties.

The peripheral tightening portion of the pressure relief plate 5 has a width necessary for maintaining airtightness as described above, and a thickness thereof is determined depending on the pressure range to be protected. Generally, pressure relief plates with standard specifications are prepared depending on the pressure range. A portion of the side plate 2 facing the opening 2a is formed with a bulging portion 5b that bulges out in a dome shape toward the inside of the case 1.

Since the bent rounded portion of the peripheral edge 2b of the opening 2a in the side plate 2 is close to this bulging portion 5b, the pressure relief plate 5
Care has been taken not to damage the

The inner and outer ends of the pressure release plate holding plate 8 are bent at approximately right angles for reinforcement.

The protection plate 17 covers the entire pressure relief plate 5, protects it from damage caused by external force, and also suppresses the influence on the outside when pressure is released.

A cutting blade 21 is provided on the inner surface of the protection plate 17, and the tip end portion of the cutting blade 21 is brought close to the mounting surface of the pressure relief plate 5. When the bulging part 5b of the pressure relief plate 5 is turned over and pushed out outward due to an abnormal increase in the internal pressure of the case,
When it hits the cutting blade 21, the pressure release plate 5 is torn and the pressure is released. When pressure is released, the protection plate 17 releases the pressure through a gap formed at the periphery, reduces the force of the pressure, and protects the contents of the case from fragments etc. directly flying outward. It is something to do.

By adopting the sealing structure as described above, the inner part of the pressure relief plate 5 where sealing with the inside of the switch case 1 is most important is completely sealed by the O-ring 3 at the peripheral edge of the pressure relief plate 5. ,
Furthermore, the groove 2c provided in the side plate 2 prevents the O-ring 3 from slipping, and the O-ring spacer 4 compresses the O-ring to a specified compression ratio, resulting in a highly reliable seal. In addition, a dust seal packing and a screw seal packing are provided to prevent water and foreign substances from entering the seal portion from the outside, so that deterioration of the seal portion over time can be prevented and reliability can be maintained over time.

[Effect of idea]

As mentioned above, according to the present invention, the multi-layered seal structure improves the airtightness inside the switch, and also prevents water and foreign matter from entering the O-ring and affecting it. However, it has the advantage of being able to guarantee long-term sealing properties.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of the pressure relief device of the present invention;
The figure is a sectional view, and FIG. 3 is an enlarged sectional view of the main part. 1... Switch case, 2... Side plate, 3... O-ring, 4... O-ring spacer, 5... Pressure relief plate,
6...Dust seal outer circumference packing, 7...Dust seal flat packing, 8...Pressure plate holding plate, 9,1
0...Bolt, 11...Positioning piece, 12...
...Screw seal gasket, 13...Seal washer, 1
4... Washer, 15... Tightening nut, 16... Spacer, 17... Protective plate, 18... Spring washer, 19... Nut, 20... Reinforcement plate, 21...
...cutting blade.

Claims (1)

[Claims for Utility Model Registration] 1. An O-ring, an O-ring spacer, and a dust seal outer circumferential packing are arranged in order from the inside around the opening of the side plate of the switch, and on top of that, at least the O-ring and the O-ring spacer are arranged. Pressure relief plates having flanges that come into contact with each other are stacked, and a dust seal flat packing is placed over the O-ring, O-ring spacer, pressure relief plate flange, and dust seal outer circumferential packing, and these are connected to the side plate by the pressure relief plate holding plate. The O-ring spacer has a seal structure that is sandwiched between the O-ring spacer and the O-ring spacer. A pressure relief device for a switch, characterized in that the pressure relief device is provided on a flange portion of a pressure relief plate, a dust seal flat packing, and the pressure relief plate holding plate. 2 Fit the screw seal gasket to the bolt that passes through the pressure relief plate holding plate, fit the seal washer that surrounds its outer periphery and regulates the compression dimension of the screw seal gasket, and then press the screw seal gasket onto the seal washer from above. A pressure relief device for a switch according to claim 1, characterized in that the contacting washers are overlapped and screwed together.