JP2000173412A - Slit arc-extinguishing device for switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely extinguish a produced arc, by surely fixing an arc spot on the outer end side of a movable electrode. SOLUTION: A movable electrode 9 is formed substantially into an L-shape and inclined by providing an arc-resistant metal 11 so that the outer end 9b side is finally separated from a fixed electrode 6. A slit part 12b in an arc- extinguishing chamber 12 is formed by connecting a slit part 12c for movable electrode passage with a narrowest slit part 12d that is a slit narrower than the thickness of the movable electrode 9 and formed on the outer end 9b side of the movable electrode 9 finally separated from the fixed electrode 6. A magnetic body 13 is attached on an outer surface of a slit wall 12j on the side of the narrowest slit part 12d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch used in high-voltage and extra-high-voltage power distribution lines, and more particularly to an improvement in an arc extinguishing device for a slit-type arc-extinguishing type air switch.

[0002]

2. Description of the Related Art Conventionally, in a high-voltage distribution line, a narrow arc extinguishing chamber type air switch has been used for opening and closing an electric circuit. In this type of air switch, a blade-type movable electrode is often used. When the electric circuit is opened, when the movable electrode is separated from the fixed electrode, an arc is generated between the movable electrode and the fixed electrode. This arc is transferred to the arcing horn provided around the fixed electrode,
An arc persists between the horn and the movable electrode. When the movable electrode is further away from the fixed electrode, the arc extends and is guided to the narrow portion of the arc-extinguishing chamber.The arc is extinguished by the arc-extinguishing gas generated from the arc-extinguishing chamber when the arc touches. Then, the electric circuit is opened.

[0003]

By the way, in the above-mentioned conventional air switch, the shape of the tip of the movable electrode is such that when an arc is generated when the electrode is separated from the fixed electrode, the tip of the movable electrode is displaced. Part and the fixed electrode become parallel,
The arc spot was not fixed and was generated over the entire end face of the electrode.

Therefore, in order to prevent the arc extinguishing performance from deteriorating, it is necessary to provide a narrow portion (slit wall) of the arc extinguishing chamber over the entire length of the passage of the movable electrode, and the shape of the arc extinguishing chamber becomes large. There was a problem.

In addition, since the movable electrode passes through the narrow portion of the arc extinguishing chamber at the time of opening and closing, it cannot be inevitably made smaller than the plate thickness of the electrode. There was a limit.

[0006]

According to a first aspect of the present invention, an arc generated when a movable electrode (9) dissociates from a fixed electrode (6) is supplied to an arc extinguishing chamber (12). A narrow arc extinguishing device for a switch, which is guided to a narrow portion (12b) to extinguish an arc, wherein the movable electrode (9) is formed in a substantially L-shape, and its outer end (9b) side is a final end. An arc-resistant metal (11) is provided so as to be spaced apart from the fixed electrode (6) and is inclined, and a narrow portion (12) of the arc-extinguishing chamber (12) is provided.
b) a movable electrode passing slit portion (12c) and a slit narrower than the thickness of the movable electrode (9), on the side where the movable electrode (9) is finally separated from the fixed electrode (6). The narrowest portion (12d) formed on the outer end (9b) side is formed continuously, and the narrow wall (12d) is formed toward the narrowest portion (12d).
The magnetic material (13) is attached to the outer surface of j).

According to a second aspect of the present invention, in the first aspect, the narrow portion (12b) of the arc-extinguishing chamber (12) is provided with a movable electrode passing narrow portion (12c) and a movable electrode passing narrow portion. The narrowest gap (12d) is narrower than the gap (12c), and the narrowest wall (12j) of the narrowest gap (12d) is the narrowest wall (12c) of the movable electrode passage narrow gap (12c). It is characterized by being formed thicker than the thickness of 12f).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described.
This will be described with reference to FIGS. Reference numeral 1 denotes a bushing made of an insulating member fitted into the case 2 and attached by bolts 3 and nuts 4.

Reference numeral 5 denotes a central conductor provided through the bushing 1. A fixed electrode 6 is provided at an end 5a located in the case 2, and an electric wire 7 is attached to the other (outside the case). ing.

Reference numeral 6 denotes a fixed electrode, which is fixed to the center conductor 5 with a screw 8. The fixed electrode 6 is formed in a substantially rectangular shape in cross section with an insertion gap for the movable electrode 9 formed in a part of the upper end, and a portion 6a in contact with the movable electrode 9 is bent inward,
The contact portion 6b has a spring property. When the movable electrode 9 described later is in a closed state, the movable electrode 9 is held by the contact portion 6b to maintain the contact pressure. Also,
An arcing horn 10 is provided outside the fixed electrode 6 so as to surround the fixed electrode 6 and make an opening 10a formed at the upper end close to the contact portion 6b. When the horn 10 is opened, an arc is generated between the horn 10 and the fixed electrode 6 to protect the fixed electrode 6.

Reference numeral 9 denotes a blade-shaped movable electrode which is inserted into and removed from the fixed electrode 6 from above in FIGS. 1 and 2 so as to open and close an electric circuit, and is opened and closed by an operation mechanism (not shown). Has become. The movable electrode 9 has a substantially L-shaped overall shape when viewed from the side, and the distal end 9a that contacts the fixed electrode 6 has its outer end 9b side finally separated from the fixed electrode 6, An arc-resistant metal 11 whose tip is lowered is provided and inclined. That is, as shown in FIGS. 1 and 4, the outer end 9 b side is formed longer than the inner end 9 c side, and the outer end 9 finally separated from the fixed electrode 6.
The lone metal 11 is attached only to b.

Reference numeral 12 denotes a slit-type arc extinguishing chamber provided so as to cover the fixed electrode 6 and the arcing horn 10, and is fixed to the bushing 1 by screws.
The arc-extinguishing chamber 12 is made of a member that decomposes upon contact of an arc of a polyacetal resin, a urea resin, a melamine resin, or the like to generate an arc-extinguishing gas, and includes an electrode housing portion 12a and a narrow portion 12b. The accommodating portion 12a accommodates a fixed electrode and the like, and the narrow portion 12b is connected to a movable electrode passing narrow portion 12c that passes when the movable electrode 9 opens and closes, and guides the generated arc to guide the generated arc. And the narrowest portion 12d narrower than the plate thickness of the movable electrode 9 in which the arc is extinguished. In particular, the narrowest portion 12d is gradually narrowed toward the outer end 12e (the left side in FIGS. 1 and 4). Further, the narrowest portion 12
The narrow wall 12j constituting d is formed thicker than the thickness of the narrow wall 12f forming the movable electrode passing narrow portion 12c in consideration of the consumption due to the concentration of the arc.

The narrow wall 12h on the inner end 12g side (right side in FIGS. 1 and 4) of the movable electrode passing narrow portion 12c is formed to be shorter in the vertical direction than the wall on the outer end 12e side. For this purpose, it is designed so that the rotation trajectory at the time of opening and closing the movable electrode 9 is reduced.

Numeral 13 denotes a magnetic body having a substantially U-shaped cross section attached by screws 14, and is made of, for example, an iron piece, a magnet, a stainless steel piece, or the like.
More specifically, the outermost portion 12i
It is attached so as to surround the outer surface of the slit wall 12j on the d side, and its opening end 13a side is fixed to the movable electrode 9 side.

Next, the operation of the arc extinguishing device of the present invention will be described. In the closed state shown in FIG. 1, when the opening operation is performed with an operation handle (not shown), the movable electrode 9 rotates clockwise. When the movable electrode 9 is separated from the fixed electrode 6 with this rotation, an arc is generated between the electrodes 6 and 9. The generated arc immediately shifts to the arcing horn 10 of the fixed electrode 6 and the movable electrode 9 and the arcing horn 10
An arc occurs continuously between them.

In this case, since the arc-resistant metal 11 on the outer end 9b side of the movable electrode 9 is finally separated from the fixed electrode 6, an arc spot is generated between the arc-resistant metal 11 and the arcing horn 10. The generated arc generates a magnetic flux M around the arc as shown in FIG. 6, and the magnetic flux M drives the arc to be extended toward the magnetic body 13 by the electromagnetic force F.

In this manner, the arc is applied to the narrowest narrow portion 12b of the narrow portion 12b of the arc-extinguishing chamber 12 on the magnetic body 13 side.
d, the internal pressure of the narrowest gap 12d is further increased, the arc voltage is increased, and the arc is blown by the increase in the generation of arc-extinguishing gas due to the arc from the narrowest gap 12d. Cooled at once and extinguished.

In this case, the narrow wall 12j of the narrowest portion 12d
Is formed thicker than the narrow wall 12f of the movable electrode passage narrow portion 12c, so that it can sufficiently withstand excessive wear caused by an arc when switching a load.

[0019]

According to the present invention, when the movable electrode is separated from the fixed electrode, the tip of the movable electrode is inclined so that the outer end side (the metal-resistant side) of the movable electrode is finally separated from the fixed electrode. The arc spot generated thereby is securely fixed to the outer end side (the metal-resistant side) of the movable electrode,
Furthermore, the generated arc is forcibly guided to the narrowest narrow portion narrower than the movable electrode passing narrow portion by the attraction action of the magnetic material attached so as to surround the outside of the narrow portion of the arc extinguishing chamber. As a result, the generated arc can be surely extinguished due to the pressure increasing effect of the narrowest gap.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a cross-sectional view of a main part showing a state in which a movable electrode is turned on.

FIG. 2 is a schematic cross-sectional view of FIG. 1 viewed from a side.

FIG. 3 is a sectional view taken along line AA of FIG. 1 excluding a movable electrode.

FIG. 4 is a sectional view of a main part showing a state in which the movable electrode is being opened from the state of FIG. 1;

FIG. 5 is a schematic cross-sectional view of FIG. 4 as viewed from the side.

FIG. 6 is a schematic diagram showing an arc extinguishing principle in an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 6 fixed electrode 9 movable electrode 9b outer end of movable electrode 11 arc-resistant metal 12 arc extinguishing chamber 12b narrow gap 12c movable electrode passing narrow gap 12d most narrow gap 12f movable electrode passing narrow slit wall 12j The slit wall of the narrowest part 13 Magnetic material

Claims (2)

[Claims] An arc switch extinguishing an arc generated when a movable electrode (9) is dissociated from a fixed electrode (6) to a narrow portion (12b) of an arc extinguishing chamber (12). In the slit arc extinguishing device, the movable electrode (9) is formed in a substantially L-shape, and its outer end (9b) side is finally fixed electrode (6).
An arc-resistant metal (11) is provided so as to be separated from the electrode and is inclined, and the narrow portion (12b) of the arc-extinguishing chamber (12) has a narrow portion (12c) for passing a movable electrode and a movable electrode (9) Outer end (9b) on the side on which the movable electrode (9) is finally separated from the fixed electrode (6)
The narrowest portion (12d) formed on the side is formed continuously.
A narrow arc extinguishing device for a switch, wherein a magnetic body (13) is provided on the outer surface of the narrow wall (12j) toward the narrowest portion (12d). 2. A narrow portion (12b) of the arc-extinguishing chamber (12).
Is composed of a movable electrode passing narrow portion (12c) and a narrowest narrow portion (12d) narrower than the movable electrode passing narrow portion (12c). 2. The movable electrode passing slit portion (12c) is formed to be thicker than the thickness of the slit wall (12f).
4. The slit arc extinguishing device for a switch according to claim 1.