JPH0516809Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a grounding device with a simplified mechanism.

B. Summary of the invention This invention is a grounding device that first indirectly grounds the busbar through a resistor and then directly grounds it, in which a first fixed contact, an insulating member, and a second fixed contact are connected to the busbar in this order. At the same time, the mechanism is simplified by providing a grounding contact that has the same axis and the same inner diameter as these fixed contacts, and is grounded, and a movable conductor that can be fitted into each of the contacts.

C. Conventional technology Recently, in urban areas etc., it is possible to
Cables buried underground are used because they do not interfere with traffic, are less likely to break down due to snow or wind and flood damage, and are highly reliable, and the installation of special high-voltage power lines in densely populated areas is prohibited by law. Electric power transmission is becoming more and more common.

However, when the above-mentioned cable is grounded, if the cable is grounded with a residual charge, a reciprocating oscillatory surge will occur in the cable core due to the sudden movement of the charge, and the core wire surge will be generated as a surge in the cable sheath. This can lead to dielectric breakdown of the cable's anti-corrosion layer.

In order to prevent this, conventionally, the grounding device has been configured as a resistor input type as shown in FIG. When the rotary lever 2 rotates in the direction of the arrow due to the action of the operating mechanism 1, the contact 5 is first connected via the moving conductor 3.
and 10 are connected, and the bus bar 4 is indirectly grounded via the resistor 6. After that, further rotate lever 2
When the contact 8 rotates, the contact 8 is connected via the moving conductor 7.
and 9 are connected, and the bus bar 4 is directly grounded.
Note that an insulating gas such as SF ₆ gas is filled in the grounding container 11 in which the bus bar 4 and the like are housed. Note that 12a and 12b are insulating rods, and 13 is an insulating plate.

D. Problems to be solved by the invention According to the above-mentioned prior art, there is one system from the operating mechanism 1 to the rotary lever 2, but the grounding device main body has two movable conductors 3 and 7 of different lengths in a fixed position. There are two systems installed in parallel with a distance between them, and as the number of parts increases, the grounding device itself becomes larger, and four contacts are required, making the mechanism complicated.

Therefore, an object of the present invention is to provide a grounding device that eliminates such drawbacks.

E Means for solving the problem The structure of the present invention to achieve this purpose is as follows:
a ring-shaped first stationary contact to which a bus bar is attached; a second stationary contact that is attached to the first stationary contact via an insulating member and has the same axis and the same inner diameter as the first stationary contact; a grounding contact having the same axis and the same inner diameter as the first fixed contact and being grounded; and a grounding contact having an outer diameter that can be fitted into each of the contacts and extending from the grounding contact to the second fixed contact and the first fixed contact. It is characterized in that it is composed of a movable conductor that is movable toward the direction.

F Effect While the tip of the moving conductor is inserted into the grounding contact, the bus bar is not grounded at all. When the movable conductor is moved toward the first and second fixed contacts and the tip of the movable conductor is fitted into the second fixed contact, the second fixed contact and the grounding contact are connected via the movable conductor, and the bus bar is connected to the grounding contact. This means that they are indirectly connected via the resistor. When the movable conductor is further moved toward the first fixed contact, the first fixed contact and the grounding contact are connected via the movable conductor, and the bus bar is directly grounded.

G. Embodiments Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

First, Example 1 will be described.

As shown in FIG. 1, a bus bar 17 is disposed within a grounding container 16 filled with an insulating gas such as SF ₆ gas. A hole 18 is bored in the convex portion formed on the bus bar 17, and a first fixed contact 19 is fitted into the entrance of the hole 18. A contact case 21 is fixed to the hole 18 via a ring-shaped insulating member 20, and a second fixed contact 22 having the same axis and the same inner diameter as the first fixed contact 19 is fitted into the contact case 21. There is.

On the other hand, a grounding container 16 is located at a position facing the hole 18.
A hole 23 is formed in the hole 23, and a contact case 25 is fixed to the hole 23 via an insulating pedestal 24. A grounding contact 26 having the same axis and the same inner diameter as the first fixed contact 19 and the second fixed contact 22 is fitted into the contact case 25, and the grounding contact 26 is grounded.

A movable conductor 27 having an outer diameter corresponding to the inner diameter of the first fixed contact 19, second fixed contact 22, and grounding contact 26 is inserted into the ground contact 26 so as to be movable in the axial direction. The base end of the moving conductor 27 protrudes from the hole 23 to the outside of the grounding container 16, and a cover 28 is provided below the hole 23 so as to cover the base end of the moving conductor 27.
is covered. A shaft 29 is rotatably supported on the cover 28 via a sealing material, and the other end of an insulating arm 30 whose one end is fixed to the shaft 29 is attached to the shaft 29.
It is connected to the base end of the moving conductor 27 via a pin 31 and a connecting fitting 32. A driving means (not shown) is connected to the shaft 29.

Next, the operation of such a grounding device will be explained.

When the arm 30 is rotated to the left by a drive means (not shown) from the non-grounded state shown in FIG. 2
2 and the grounding contact 26 are connected via the moving conductor 27, and the bus bar 17 is indirectly grounded via the resistor 20. When the arm 30 is further rotated to the left, the moving conductor 27 also comes into contact with the first fixed contact 19, current flows from the first fixed contact 19 to the grounding contact 26 via the moving conductor 27, and the bus bar 17 is directly connected to the grounding contact 26. This means that it is grounded. That is, first it is indirectly grounded through a resistor, and then it is directly grounded.

In order to release the grounding state of the bus bar 17 from the grounding state, it is sufficient to reversely rotate the bus bar 30 to the right.

Next, Example 2 of the grounding device according to the present invention will be explained as follows.
This will be explained based on FIGS. In addition, Example 1
The same reference numerals will be used for the same parts, and the explanation will be omitted, and only the different parts will be explained.

As shown in FIG. 2, in this embodiment, a contact case 25 is fixed to the hole 23 via an insulating pedestal 33 and a cylinder 34. As the moving conductor, a longer moving conductor 35 is used than in the first embodiment due to the provision of the cylinder 34, etc., and the moving conductor 35 passes through the cylinder 34 so as to be movable. A piston 36 that is slidable within the cylinder 34 is fixed to the movable conductor 35, and a flow path 33 is formed from an injection port 37 formed at the tip of the movable conductor 35 to below the piston 36 in the figure.

In such a grounding device, as for grounding, Example 1 is used.
is the same as , but the difference is when the ground is released. As shown in FIG. 3, when the arm 30 is rotated to the right from the grounded state, the movable conductor 35 first separates from the first fixed contact 19 and then also separates from the second fixed contact 22. If there is a live wire adjacent to the bus bar 17, the moving conductor 35 will be removed from the bus bar 17 when grounding.
An electromagnetic induction current or an electrostatic induction current flows to the second fixed contact 22 and the moving conductor 35, and an arc is generated between the second fixed contact 22 and the moving conductor 35 as they separate. In this embodiment, as the moving conductor 35 moves, the cylinder 34 and the piston 3
SF ₆ gas etc. that entered between piston 3 and 6
6 and passes through the flow path 38 to the injection port 3.
7 to the second fixed contact 22. Therefore, no arc occurs between the moving conductor 35 and the second fixed contact.

H. Effects of the invention As explained above, according to the invention, the first fixed contact, the insulating member, and the second fixed contact are attached to the bus bar in this order, while having the same axis and the same inner diameter as these fixed contacts, and being grounded. Since grounding contacts are provided and movable conductors are provided that can be fitted into each of the contacts, the mechanism of the grounding device is simple and there are fewer failures.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of a grounding device according to the present invention, FIGS. 2 and 3 are a sectional view showing a second embodiment of the grounding device according to the present invention, and FIG. 2 is a sectional view showing a non-grounded state. FIG. 3 is a cross-sectional view showing the state when the earthing device is released, and FIG. 4 is a cross-sectional view of a conventional earthing device. 17... bus bar, 19... first fixed contact,
20... Insulating member, 22... Second fixed contact, 26... Grounding contact, 27... Moving conductor.

Claims (1)

[Scope of utility model registration request] a ring-shaped first fixed contact attached to the bus bar; a second fixed contact attached to the first fixed contact via an insulating member and having the same axis and the same inner diameter as the first fixed contact; a grounding contact having the same axis and the same inner diameter as the first fixed contact and being grounded; and a grounding contact having an outer diameter that can be fitted into each of the contacts and extending from the grounding contact to the second fixed contact and the first fixed contact. A grounding device comprising a movable conductor that is movable toward the ground.