JPH0729537Y2 - Disconnector for gas insulated switchgear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a disconnector for a gas insulated switchgear, which is responsible for opening and closing a current such as a loop current and a load current.

[Prior Art] FIG. 4 shows a configuration of a main part of a conventional disconnector of this type.
In FIG. 1, reference numeral 1 is a hollow fixed base, 2 is a V-shaped insulating support base supported by the fixed base 1, and 3 and 4 are fixed-side elements and movable-side elements supported by the insulating support base 2, respectively.

The fixed side element 3 is a fixed electrode fixed to the support base 2.
301, a contactor base 302 connected to the fixed electrode 301, a tulip-shaped fixed contact 303 supported by the contactor base 302, and an arc contact 304 provided in the center of the contactor base 302, It is composed of a cup-shaped fixed contact side shield 305 attached so as to cover the fixed contact 303, and a hole 306 is formed in the fixed contact side shield 305 for passing a movable contact described later.

The movable element 4 is slidably fitted to a frame 401 also serving as an electrode, a tulip-shaped sliding contact 403 supported by a contact table 402 attached to the frame 401, and a cylinder portion provided in the frame 401. Attached to the sliding plate 404 that is attached to the contact plate 4 via the sliding contact 403.
A tubular movable contact 405 electrically connected to 02,
A lever 407 rotatably supported by the frame 401 via a shaft 406 and one end of which is coupled to a rear end of the movable contact via a link 408, and a movable contact-side shield 409 covering the vicinity of the sliding contact 403. ing.

One end of the insulating operation rod 5 is pivotally coupled to the other end of the lever 407, and the other end of the insulating operation rod 5 is disposed inside the fixed base 1 and is rotatable on the fixed base 1 via a shaft 6. It is connected to a supported lever 7. A lever 8 is also attached to the shaft 6, and the lever 8 is connected to an operating device (not shown) via an operating link 9. FIG. 4 shows a closed state of this disconnector, in which the tip of the movable contact 405 contacts the fixed contact 303 from the inside, and the arc contact 304
Are in contact with each other while being engaged with the inner circumference of the tip of the movable contact 405.

The above disconnecting switch is placed in the container of the gas insulated switchgear in which an insulating gas such as SF ₆ gas is sealed. A fixed side terminal and a movable side terminal (neither is shown) are connected to the fixed electrode 301 and the frame 401, respectively, and in the closed state shown in FIG. 4, the frame 401 → sliding contact 403 → movable contact 405 → A current flows through the path from the fixed contact 303 to the fixed electrode 301 or the opposite path.

When the operation link 9 is pulled in the direction shown by the arrow in the state shown in FIG. 4, the levers 8 and 7 rotate clockwise in the drawing. This rotation is transmitted to the lever 407 via the insulating operation rod 5, so that the lever 407 rotates clockwise and the movable contact 405
Is linearly displaced in the direction away from the fixed contact 303.
At this time, the movable contact 303 first separates from the fixed contact 303 and then separates from the arc contact 304. When the movable contact 303 is separated from the arc contact 304, an arc is generated between the contacts, but the arc is extinguished by an appropriate arc extinguishing means such as gas blowing.

[Problems to be Solved by the Invention] When the disconnecting switch is turned on, the operation link 9 is displaced in the direction opposite to the arrow shown in FIG.
5 is displaced to the fixed contact 303 side. FIG. 5 shows the state immediately before the disconnecting switch shown in FIG. 4 is turned on.
When this disconnector has the responsibility of switching the load current, opening and closing the loop current, or turning on the short-circuit current, the movable contact 405 is slightly different depending on the conditions, but as shown in FIG. Before contact 304 3
A leading arc occurs between the tip of the movable contact 405 and the arc contact 304 when approaching up to a position (about 4 mm). The heat of the preceding arc heats the tip of the movable contact 405 and the arc vicinity of the arc contact 304 to melt a part of each, and the molten metal becomes vapor-like and scatters in the gas space. When the loading operation progresses further,
The movable contact 405 contacts the arc contact 304 to extinguish the arc, and then the movable contact 405 contacts the fixed contact 303 to complete the closing operation. When the movable contact 405 comes into contact with the arc contact and the fixed contact, since each contact is heated to a high temperature by the preceding arc, a larger amount of molten metal (contact material) is gasified by the impact of the contact. It will be scattered in space. If the scattered metal adheres to the surface of the insulating support base 2, the dielectric strength between the charging part and the ground will be reduced. Further, when the molten metal adheres to the surfaces of the shields 305 and 409, the smoothness of the shield surface is lost, so that the electric field in the vicinity of the shield is disturbed and the withstand voltage performance between the electrodes may be deteriorated.

An object of the present invention is to provide a disconnector for a gas insulated switchgear in which vapor of metal that is heated and melted by a preceding arc is prevented from scattering into a gas space and the withstand voltage performance is reduced. is there.

[Means for Solving the Problems] The present invention comprises a fixed contact, a movable contact provided so as to come into contact with and separate from the fixed contact, and a fixed contact side shield provided so as to cover the fixed contact, The present invention relates to a disconnector for a gas-insulated switchgear having a duty of switching current.

In the present invention, there is provided an insulating cover which has a hole for passing the movable contact and is formed so as to cover the fixed contact side shield from the outside. The size and position of this insulating cover are set so as to generate a preceding arc generated between the movable contact and the fixed contact in the insulating cover at the time of making, and the tip of the movable contact is insulated at the time of making. The wall thickness in the vicinity of the hole of the insulating cover is set to be sufficiently large so that the preceding arc discharge is started between the tip of the movable contact and the fixed contact after entering the hole of the cover.

[Operation] When the fixed contact side shield is covered with the insulating cover as described above, the tip of the movable contact enters the hole of the insulating cover and the movable contact substantially closes the hole of the insulating cover, and then the insulating cover. Since the leading arc is generated inside the metal, the metal vapor generated by melting the contact due to the heat of the leading arc is mostly confined inside the insulating cover. Therefore, the molten metal vapor does not scatter into the gas space, and it is possible to eliminate the possibility that the scattered metal adheres to the surface of the insulating support or the surface of the shield to lower the dielectric strength.

Further, when configured as described above, since it suffices to cover the fixed contact side shield from the outside with an insulating cover whose size, position and wall thickness are appropriately set, without particularly complicating the structure of the disconnector, It is possible to prevent the molten metal vapor generated by the preceding arc from scattering into the gas and prevent the insulation performance from deteriorating.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a fixed base, 2 is a V-shaped insulating support supported by the fixed base 1, and 3 and 4 are respectively supported by the insulating support 2. These are fixed side elements and movable side elements, and of these, the parts other than the fixed side element 3 are configured in exactly the same manner as the example shown in FIG.

The fixed-side element 3 includes a fixed electrode 301 fixed to the support base 2, a contact piece base 302 connected to the fixed electrode 301, and a tulip shape supported by the contact piece base 302 as in the example of FIG. Of the fixed contact 303, the arc contact 304 provided in the central portion of the contact child base 302, and the cup-shaped fixed contact side shield 305 formed to cover the fixed contact 303 and attached to the contact child base 302. In the present invention, the fixed contact side shield 305 is provided.
An insulating cover 310 is provided to cover the. The insulating cover 310 has a shape that is substantially similar to the shield 305 (substantially cup-shaped), and a hole 311 for allowing the movable contact to pass through is provided in the center thereof. This insulating cover 310 has a hole
311 is aligned with the central hole 306 of the shield 305, and is arranged close to the shield 305 so as to cover the shield 305 from the outside and is fixed to the contact base 302 together with the shield 305.

The illustrated insulating cover 310 is made of an insulating material such as an epoxy resin or a tetrafluoroethylene resin (trade name Teflon), and is formed so that the thickness gradually increases from the peripheral portion toward the central portion. Immediately before the tip of the movable contact 405 contacts the fixed contact 303, after the tip of the movable contact 405 enters the hole 311 of the insulating cover 310, the tip of the movable contact is on the inner peripheral surface of the hole 311 for a certain period. The wall thickness t1 near the hole 311 is set to be sufficiently large so as to maintain the facing state. Then, as shown in FIG. 2, when the tip of the movable contact 405 enters the hole 311 of the insulating cover 310 for a certain distance t2 at the time of insertion, the tip of the movable contact and the fixed contact 303 are separated from each other. So that the preceding arc discharge A is started at
The position of the opening of the hole 311 of 0 and the wall thickness t1 near the hole are set. Here, t1 is, for example, 10 to 20 mm, and t2 is 5 to 10 mm. In addition, the heat of the preceding arc causes an insulating cover
In order to prevent the vapor of the molten metal generated in 310 from flowing out through the hole 311 as much as possible, the inner diameter of the hole 311 is set to the minimum necessary size for passing the movable contact 405 without any trouble. .

When the insulating cover 310 as described above is provided, most of the molten metal vapor generated by the heat of the preceding arc A at the time of charging is confined in the insulating cover 310, so the molten metal vapor is scattered in the gas space outside the insulating cover 310. It is possible to prevent the metal vapor from adhering to the outer surface of the insulating support base 2 and the outer surface of the movable contact side shield 409.

In particular, as in the above-described embodiment, if the leading arc of the movable contact 405 enters the hole 311 of the insulating cover 310 and then the preceding arc is generated, the hole 311 is already formed when the preceding arc occurs. Since it is substantially closed, the effect of preventing the scattering of the molten metal vapor can be enhanced.

In the above embodiment, the insulating cover 310 is formed separately from the fixed contact side shield 305, but the insulating cover 310 is, for example, a molded product of epoxy resin, and the shield 305 is cast when molding the insulating cover. The insulating cover 310 and the fixed contact side shield 305 can be integrated.

Further, the fixed contact side shield 305 does not necessarily have to be made of a metal having self-supporting property (having a strength capable of maintaining the shape by itself without the aid of other members), and as shown in FIG. , The insulating cover 310 is formed of, for example, tetrafluoroethylene resin, and the insulating cover 310
It is also possible to form a conductive layer by applying a conductive paint such as silver paint or performing electroless plating on the inner surface, and form the fixed contact side shield 305 by the conductive layer.

[Advantage of the Invention] As described above, according to the present invention, the fixed contact side shield is covered with the insulating cover having the hole for passing the movable contact, and the tip of the movable contact is inside the hole of the insulating cover at the time of insertion. Since the wall thickness near the hole of the insulating cover was set to be sufficiently large so that the preceding arc discharge started between the tip of the movable contact and the fixed contact after entering the After plugging, the preceding arc is generated inside the insulating cover, and the metal vapor generated by melting the contact due to the heat of the preceding arc can be mostly confined inside the insulating cover, and a large amount of molten metal vapor is generated in the gas. There is an advantage that it is possible to prevent scattering in the space and eliminate the possibility of lowering the dielectric strength.

Further, according to the present invention, since it is sufficient to cover the fixed contact side shield from the outside with the insulating cover whose size, position and wall thickness are appropriately set, the structure of the disconnecting switch is not particularly complicated. It is possible to prevent the molten metal vapor generated by the arc from scattering into the gas and prevent the insulation performance from deteriorating.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of an essential part showing the relationship between the tip of the movable contact and the hole of an insulating cover in the embodiment of FIG. 1, and FIG. FIG. 4 is a sectional view showing a modified example of the insulating cover and the fixed contact side shield used in the present invention, FIG. 4 is a sectional view showing a closed state of a conventional disconnector, and FIG. It is sectional drawing which shows a state. 1 ... Fixed base, 2 ... Insulating support base, 3 ... Fixed side element, 301 ... Fixed electrode, 302 ... Contact base, 303 ... Fixed contact, 304 ... Arc contact, 305 ... Fixed contact Side shield, 310 ... Insulation cover, 311 ... Hole of insulation cover, 4 ... Movable element, 401 ... Frame, 402 ... Contact base, 403 ... Sliding contact, 405 ...
… Movable contact, 407 …… Lever, 408 …… Link, 40
9: Movable contact side shield, 5: Insulation operating rod,
6 …… Axis, 7,8 …… Lever, 9 …… Operation link.

Claims (6)

[Scope of utility model registration request] 1. A gas insulation having a fixed contact, a movable contact provided in contact with and separated from the fixed contact, and a fixed contact side shield provided so as to cover the fixed contact, and having a current switching duty. The switchgear for a switchgear comprises an insulating cover formed to cover the fixed contact side shield from the outside with a hole for passing the movable contact, and the movable contact and the fixed contact at the time of closing. The size and position of the insulating cover are set so as to generate a preceding arc that occurs in the insulating cover, and when the tip of the movable contact enters the hole of the insulating cover at the time of closing. Meat near the hole of the insulating cover so that a preceding arc discharge is started between the tip of the movable contact and the fixed contact. Disconnector for gas insulated switchgear, wherein a is set sufficiently large. 2. The disconnector for a gas insulated switchgear according to claim 1, wherein the insulating cover is integrated with the fixed contact side shield. 3. The utility model registration claim wherein the insulating cover is made of a synthetic resin molded product, and the fixed contact side shield is formed by a conductive layer formed on the inner surface of the insulating cover. The disconnector for gas-insulated switchgear according to claim 2. 4. The utility model registration, wherein the fixed contact side shield is made of a conductive material having self-supporting property, and is integrated with the insulating cover in a state of being cast into the insulating cover. The disconnector for gas-insulated switchgear according to claim 3. 5. The disconnector for a gas-insulated switchgear according to claim 2, 3, or 4, wherein the insulating cover is made of epoxy resin and registered as a utility model. 6. The utility model registration claim in which the insulating cover is made of tetrafluoroethylene resin, claim 2, claim 3, or claim 4.
A disconnector for a gas insulated switchgear according to any one of paragraphs.