JPS60113607A - Enclosed switchboard - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a shutoff system in which a plurality of electrical devices are housed in a starting/closing switch filled with an insulating material such as SF or gas (hereinafter referred to as gas). This invention relates to switchboards, particularly to improving the sealing structure of openings provided in sealed containers.

[Technical backwaters of the invention and its 11j problems] In recent years, Ruru 66/77 ay class closed switchboards for power receiving and transforming equipment for electric power and general industry have been developed to improve the efficiency of installation space, reduce equipment costs, and improve operability. In order to achieve the same result, a gas filled with a gas with excellent insulating properties came to be used.

By the way, the conventional closed switchboard filled with gas has a -
As an example is shown in FIG. 1, a lightning arrester 21, a lightning arrester transformer 3. disconnector 4,
A grounding device 5, a breaker 6, a current transformer 7, and other devices are installed, and these devices are connected to the bus bar 0 via a cable head 8 connected to a transformer (not shown) and a connecting conductor 9.
It is connected to the. Further, the closed container 1 is provided with an opening 11 that serves as an entrance/exit for carrying in the above-mentioned devices for installation therein or for maintenance/inspection. This opening 11 is located inside the airtight container 1 (2) after the above-mentioned devices have been installed several times or after inspection is completed, it is necessary to maintain airtightness to prevent gas leakage, so the backing 12 is closed with a valve. It is closed with an airtight lid 13.In particular, in the closed switchboard, since many devices are installed adjacent to each other inside the airtight container 1, insulation between each device is the most important. Gas is pressurized and sealed to further improve the performance.

The dielectric strength of the gas in the sealed container 1 is given by the force.

Since it is related to pressure, it is necessary to maintain a predetermined pressure in order to obtain the desired P3 edge stiffness.

Therefore, the sealed container 1 is a so-called pressure container and is made of a thick steel plate to increase mechanical strength compared to a closed switchboard that does not contain normal gas. Moreover, the transportation equipment involved in the assembly, transportation, and installation of a closed switchboard is also large, and the means of transportation requires a large number of man-hours.

As a result of recent research into gas insulation technology, it was found that the desired dielectric strength could be obtained even if the pressure of the gas inside the sealed container was lower than before, and a closed switchboard filled with low-pressure gas was manufactured. It's starting to happen. This results in
It is no longer necessary to use a conventional pressure vessel as a closed vessel, and a non-pressure vessel is sufficient; that is, in terms of mechanical strength, it has become possible to use almost the same structure as a normal one without sealing in gas. Therefore, since the container can be made of thin steel plates joined by H-weld, the appearance can be greatly reduced and the above-mentioned drawbacks can be eliminated.

However, closed switchboards filled with low-pressure gas (hereinafter referred to as "closed switchboards") cannot maintain the desired dielectric strength if gas leaks from the closed container, resulting in accidents such as short circuits. may cause damage to the equipment or create an emergency (-dangerous situation) such as an explosion due to a sudden increase in internal pressure.

Therefore, the sealed container of this closed switchboard is required to have a structure that is sufficiently airtight without gas leakage. ! ,′
It is hoped that it will be possible to easily detect fc gas leaks.

Therefore, in the closed container of the present closed switchboard, the airtightness of the opening 11 is likely to become a problem. That is, the airtight lid J3 is attached via the gasket 12, but since the steel plate forming the airtight container is thin, the mounting surface is easily deformed, and gas leaks from this deformed portion. Also, in this type of structure,
Gas leaks cannot be detected effectively.

[Objective of the Invention] The present invention has been made in view of the above circumstances, and by improving the sealing structure of the opening of a sealed container, it is possible to manufacture a sealed container with a thin steel plate, and significantly reduce Iv. The purpose of the present invention is to provide a closed switchboard filled with insulating gas that can

[Summary of the invention] The present invention includes a sealed container made of a thin steel plate, a circular flange with an opening formed on one side of the sealed container, and a sealed lid attached to the circular flange via a backing. This is a closed switchboard that significantly reduces weight and improves reliability by eliminating gas leaks.

“Embodiments of the invention” An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 2, 3, and 4, a sealed container 2 is formed of a thin copper plate into approximately the same shape as a conventional one by bath welding.
1E is a negative surface (a two-circular opening 22 is provided, a cylindrical portion 23 made of a steel plate is hermetically bath welded to protrude along this opening 22, and this circular portion 2
3 has a circular flange 24 (which is hermetically welded to the flange 24).The flange 24 has a circular sealing groove 25, and the sealing groove 25 is inserted into the sealing groove 26. A circular closing lid 27 having the same shape as the flange 24 is attached with bolts 28 and nuts 29 so as to press against and seal the QIJ ring 25.

Therefore, a crab made of thin steel plate? 5 is.

Due to its low rigidity, it is difficult to attach the closed lid to the conventional closed container made of thick steel plate (2), and the 1lli'6 attachment part is deformed, causing gas leakage. Although it had the disadvantage of causing leakage, as mentioned above (-
By providing strength to the flange 24, the O-ring 2
6 (: It is possible to apply the necessary tightening pressure to maintain airtightness. In addition, an O-ring 26 is used as a backing.
Since the seal N25 is circular, it can be tightened evenly around the entire circumference, and the deformation of the O-ring 26 is uniform, so a sufficient sealing effect can be obtained.

This type of seal configuration completely solves the problems that occur when the conventional opening is square (secondly, the seal area is large, and the backing is bent at right angles at the corner, causing gas leakage). It is.

Next, a method for detecting gas leakage from the sealed structure of the opening will be explained. As mentioned above, flange 2CO! j
25) Since the hermetic structure of the opening 22 consisting of the airtight lid 26 protrudes from the surface of the airtight container 21 through the cylindrical portion 23, the airtight structure of the opening 22, as shown in FIG. A collection bank 30 made of a rubber bag is placed over the collection bank 30, and the collection bank 30 is locked to the cylindrical portion n with an elastic retaining ring 31. After a certain period of time has elapsed, a sampling needle is inserted into the collection bank 30 to collect the gas inside, and the concentration of this gas is analyzed, thereby making it possible to easily and accurately measure the gas.

As is well known (2. In most cases, gas leaks in closed containers occur from the sealed structure at the opening. Therefore, the gas leak detection method described above (2. Needless to say, such gas leak detection cannot be carried out in conventional devices in which the sealing structure portion of the opening does not protrude from the surface of the closed container.

Next, another embodiment of the present invention will be described with reference to the drawings. Fourth
Part 6, in which the same parts as those in the figure are given the same reference numerals and their explanations are omitted.
In the figure, a closed container 211-1 is provided with a flange 32 that is substantially integrated with a flange 24 having the same shape as the cylindrical portion 23 of the previous embodiment.

In this case, the flange 32 is provided with a screw 32a, the bolt 28 is screwed in, and the sealing lid 27 is attached.

Next, an application example of the present invention will be explained. In FIG. 7, similarly to the embodiments shown in FIGS. 2 to 4, the airtight container 35 is also provided with an opening (not shown) on its negative side, and a cylindrical portion 36 and a cylindrical portion 36 are formed along this opening. Further, circular flanges 37 are provided on the cylindrical portion 36 in an airtight manner by welding. Therefore, the above-mentioned airtight container 21 and both flanges 24.37
are brought into contact with each other, and with the O-ring 25 interposed, bolt 28. A nut 29 is used to connect the inner sealed containers to form a composite closed switchboard. In this case as well, a plurality of closed containers can be easily connected while maintaining airtightness, and reliability can of course be ensured.

[Effect of the invention] Misfiring gA! Since the structure is as described above, even if the airtight container that seals the gas is made of thin plates, the gas will not leak from the airtight structure at the opening.

The plate thickness of the sealed container can be reduced to a fraction of that of the conventional one, which not only makes the sealed container lighter and easier to assemble.
Efficiency in transportation, installation, etc. is greatly improved. In addition, there is no gas leakage, so it can be used for a long time! There is no risk of 3-edge lowering or short-circuit accidents, and stable operation is possible, making maintenance extremely easy.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional closed switchboard filled with insulating gas, Fig. 2 is a front view showing an embodiment of the present invention, and Fig. 3 is a side view taken in the direction of arrow A in Fig. 2. , Figure 4 is B in Figure 3.
5 is an explanatory diagram showing the insulating gas leakage detection method related to the present invention;
The figure is a sectional view showing the main part of another embodiment of the present invention, and FIG. 7 is an explanatory diagram showing the structure of a composite type closed switchboard related to the present invention. 21... Airtight container 22... Opening 23... Cylindrical part 24... Flange 26... O-ring 27...
・Airtight Lid Agent Patent Attorney Yoshiaki Inomata (1 person)
Figure 1 f 71. ,! ,,3 (77L Figure 2 Figure 3 Figure 4 Figure 5 (

Claims (1)

[Scope of Claims] (1) In a closed power distribution board in which electrical equipment is housed in a closed container filled with an insulating gas, a circular flange with an opening formed in one side of the closed container is provided, and a backing is attached to the circular flange. (2) The closed power distribution board according to claim 1, characterized in that the circular flange is attached to the closed container through a cylinder.