JPS6115541B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to magnetic disconnectors, air disconnectors, direct current disconnectors, etc., and particularly relates to improvements in the arc extinguishing chamber.

Figures 1 and 2 show the arc extinguishing device of a conventional arc breaker.
This will be explained with a diagram. In the figure, a pair of conductors 2 and 3 which are cut off by a wire are arranged in the lower part of an outer box 1, and a fixed main contact 4 and a fixed arc contact 5 are attached to the end of one of the conductors 2. A lower end of a movable arc contactor 6 which also serves as an operating rod is rotatably attached to one end of the other conductor 3, and a part of the movable arc contactor 6 is connected to the fixed main contactor 4 in the middle. A movable main contactor 7 is provided for separating.
A pair of arc runners 8 and 9 that expand upward are provided above the contact portion between the fixed arc contact 5 and the movable arc contact 6, and the arc runner 8 on the left in the figure is a connecting conductor. The right arc runner 9 is connected to the conductor 3 via a connecting conductor 11. Arc guide plates 12 and 13 are provided on both sides of these arc runners 8 and 9 to protect the outer box 1 from arc heat and to maintain an appropriate gap for rapid arc expansion. It is being Further, in the outer box 1 above the arc guide plates 12 and 13, there is provided an arc barrier laminate 14 formed by laminating plate-shaped silcon porcelain or the like. Each laminate of the arc barrier laminate 14 is provided with an inverted V-shaped groove 15, and
The grooves 15 are formed so as to be inclined in opposite directions in each adjacent laminate (see FIG. 2). Further, the pair of arc guide plates 12, 13
As shown in FIG. 2, the gap formed between the pair of arc guide plates 12 and 13 is tapered so that it gradually decreases as it goes upward.
This taper has a gap with a distance L ₁ at the bottom that is wide enough to accommodate the fixed arc contact 5,
The gap is so narrow that the distance L ₂ at the top is somewhat wider than the width of the arc runners 8 and 9.

In such a configuration, when the movable arc contactor 6 is driven by a drive mechanism (not shown), the main contacts 4 and 7 are first separated, and then the arc contactors 5 and 7 are separated.
6 opens. Due to this separation of the arc contacts 5 and 6, an arc 1 is generated between these arc contacts 5 and 6.
6 is generated, and this arc 16 moves from between the arc contacts 5 and 6 to between the arc runners 8 and 9 as shown in A, B, and C in FIG. 1 due to its own electromagnetic force and thermal natural upward force. It moves, further rises, and disappears within the arc barrier laminate 14. In the initial state where the arc 16 is generated and gradually expands, that is, at the stages indicated by A and B in FIG. As shown in Figure B, it has an approximately circular cross-sectional shape. For this reason, as shown in FIG. 1, the longitudinal cross-sectional shape of the arc 16 becomes relatively thin and narrow, and the arc 16 of A or B extends and reaches the tip 8A of the arc runner 8 or the tip 9A of the arc runner 9. It takes time for one side edge in the width direction to come into contact with each other, and this causes an increase in arc time and generation of a large amount of hot ionized gas at the lower part of the arc guide plates 12 and 13. Because of this phenomenon, even after the arc 16 enters the arc barrier laminate 14, re-ignition often occurs near the arc contacts 5 and 6 due to the influence of the ionized gas, making the cutting performance unstable. There was this inconvenience.

In addition, only the fixed arc contact has a wide gap,
A wire cutter has been proposed in which an arc guide plate is formed so that the gap is narrow in the other parts, but in this case, in the case where only the part closest to the fixed arc contactor has a wide gap, If the airflow between the fixed arc contact and the movable arc contact does not flow smoothly, especially when the booster blows air between the movable arc contact and the fixed arc contact, the air from the booster may There is a problem in that the blow-through of the arc becomes poor and smooth rise of the arc cannot be expected.Furthermore, even while the separation distance of the movable arc contact is small, the gap around the movable arc contact is narrow. There is a drawback that restriking occurs easily in parts other than the arc contactor, and the shearing performance becomes unstable.

An object of the present invention is to provide a breaker with good breaker performance.

The present invention makes the gap formed by a pair of arc guide plates wide only within a predetermined range near the movable and fixed arc contacts that move toward and away from each other, thereby allowing airflow to flow in the fixed arc contact portion. The above objective is achieved by improving the arc contact, preventing restriking at the initial stage of opening of the movable arc contact, and increasing the ascending speed of the arc by narrowing the gap at the part remote from the fixed arc contact. This is what I am trying to do.

Embodiments of the present invention will be described below based on the drawings. Here, the same or equivalent components as in the prior art example are designated by the same reference numerals.

3 and 4 show an embodiment in which the present invention is applied to a magnetic shield breaker, in which conductors 2 and 3 are provided at the bottom of the outer box 1, and one end of these conductors 2 and 3 is provided. are provided with a fixed main contact 4 and a movable main contact 7, as well as a fixed arc contact 5 and a movable arc contact 6, which move toward and away from each other. Above these contacts 4, 7, 5, 6, that is, in the direction of the arc extinguishing chamber, arc runners 8, 9 which face upward and expand in a V-shape are provided, and these arc runners 8, 9 are connected. It is connected to conductors 2 and 3 via conductors 10 and 11, respectively, so that it has the same potential as the conductors 2 and 3. Arc guide plates 21 and 22 consisting of a pair of insulating parts are provided on both sides of these arc runners 8 and 9, and above the arc guide plates 21 and 22 and inside the outer box 1, a large number of zircon porcelain An arc barrier laminate 14 made up of laminated plates is provided. Each plate of the arc barrier laminate 14 is provided with inverted V-shaped grooves 15 bent in opposite directions in adjacent plates, and these V-shaped grooves 15 stretch the arc 16 in a loop shape. It is like that.

The pair of arc guide plates 21 and 22 are formed so that the gap formed between the arc guide plates 21 and 22 becomes a wide gap part 23 in the vicinity of the fixed arc contact 5, and the tapered part 24 is In most areas, a narrow gap 25 is formed. At this time, the range of the wide gap 23 is extended to the position where the arc 16 is no longer generated in areas other than between the fixed arc contact 5 and the movable arc contact 6 when the movable arc contact 6 is opened. This is the range inside the movable arc contactor 6 when the arc contactor 6 moves, and the taper portion 24 has an apex angle formed on both sides thereof in a range of 60 to 120 degrees.

In such a configuration, the movable arc contactor 6
When the is driven in the opening direction by an operation mechanism (not shown), the fixed main contact 4 and the movable main contact 7 are first separated, and then the fixed arc contact 5 and the movable arc contact 6 are separated. An arc 16 is generated between both arc contacts 5 and 6. This arc 16 is the third
When the arc 16 extends from state A to state B in the figure, the entire arc 16 enters the narrow gap 25, so the arc 1
The cross section of 6 no longer has a cylindrical shape, and has been crushed by the arc guiding plates 21 and 22, as shown by B in FIG. For this reason, arc 1
The cross-sectional shape of 6 is a so-called band-shaped arc 16, as shown in FIG. It is known from basic magnetic research that such an arc 16 extends extremely efficiently in the direction of extension, and the arc 16 in state B in Fig. 3 is an arc runner. It can reach the tip 9A of No. 9 in a short time, and then pass through state C and move toward the arc barrier laminate 14 in a short time. As a result, the residence time of the arc 16 at the lower part of the arc guide plates 21 and 22 is shortened, and the arc 16
The restriking phenomenon that occurs between the arc contacts 5 and 6 after the arc expands into the arc barrier laminate 14 is effectively suppressed, and the shearing performance is stabilized.

Furthermore, in this embodiment, a wide gap is provided in front of the fixed arc contactor 5, that is, in the area P, but this means that even if the gap is narrow, the band-shaped arc remains is difficult to stretch,
Also, when a band-shaped arc is formed in this area P, the lower edge of the band-shaped arc is prevented from firing in the lower area Q of the fixed arc contact 5, and the arc 16 is extended to B and C. After the arcing, the density of the ionized gas remaining between the two arc contacts 5 and 6 is reduced to further increase the effect of preventing restriking, and furthermore, the area from the small current breaker booster (not shown) is This is done in consideration of the fact that the blowing of air to P acts effectively between the arc contacts 5 and 6. In particular, even when a small current is interrupted, the air flow blown between the arc contacts 5 and 6 easily blows through the wide gap 23 and is accelerated in the narrow gap 25, so that it is unstable or breaks. Performance.

Furthermore, if the taper portion 24 is made too steep, it will prevent the arc 16 from extending from state A to state B, and if it is made too loose, it will become the same as before and will not be as effective. The above angle is desirable.

As described above, according to this embodiment, the area near the fixed arc contactor 5 is made into the wide gap part 23, and most areas of the arc guiding plates 21 and 22 are made into the narrow gap part 25 through the tapered part 24. Since it was formed, arc 16
can be extended well, shorten the arc time, prevent the re-ignition phenomenon between the arc contacts 5 and 6, ensure stable shearing performance, and improve air flow during air blowing for small currents. Effects such as improved breaking performance for small currents can be expected.

Next, a specific example of the dimensions of the gap formed between the arc guide plates 21 and 22 in the shingle breaker of the present invention will be explained based on FIGS. 5 and 6.

The width of the wide gap 23 formed between the arc guide plates 21 and 22 is D, the angle of the inclined surface of the tapered part 24 with respect to the vertical line is θ, and the width of the narrow gap 25 is d.
Wide gap 23 from the top end of the fixed arc contact 5
Assuming that the distance to the upper end is l ₁ and the distance from the right end _of the fixed arc contact 5 in FIG. With a power disconnector of about 10,000 A, d = 20 to 25 mm, D
= 45 mm, θ = 45 degrees, l ₁ = 5 ~ 50 mm, l ₂ = 5 ~ 20 mm
is good, and at 30,000 A, d = 15 to 25
mm, D=40 mm, and the other values were approximately the same as 60,000 A. From these results, d=10~25
mm, D=30 mm or more, and it is necessary to provide a wide gap 23 of at least 5 mm or more around the fixed arc contact 5 in the direction of the arc extinguishing chamber. At this time, the dimension l ₂ is equal to the distance where no arc other than the arc 16 that has already occurred between the two arc contacts 5 and 6 occurs when the movable arc contact 6 is opened and moved, and is usually 5 mm. Any above is sufficient. Also,
The thickness of the movable arc contactor 6 is approximately 5 to 10 mm.

In addition, in the above embodiment, the arc guide plate 2
The shapes of the wide gap part 23, the tapered part 24, and the narrow gap part 25 formed by the arc guiding plates 21 and 22 extend in a semicircular arc shape from the lower ends of the arc guide plates 21 and 22, and have their upper sides extended horizontally. Although the tapered portion 24 is defined by a tapered portion 24, the shape of the tapered portion 24 is not limited to the shape shown in FIG. 3, but may be as shown in FIGS. Also good. That is, FIG. 7A shows the tapered portion 24.
is a 1/4 arcuate part, B is a straight part bent in three places, C is a shape in which almost orthogonal straight parts are connected with a small radius, and D is a top end part. A slight radius is formed at the edge, and the shape extends diagonally downward in a straight line from this radius. Further, although the fixed arc contactor 5 has a horn portion in the above embodiment, it is not necessary to provide this horn portion, and other shapes may be used.

As described above, according to the present invention, it is possible to provide a disconnector with good shearing performance.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing the arc extinguishing device of a conventional shingle breaker, Fig. 2 is a sectional view taken along the line - in Fig. 1, and Fig. 3 is a cross-sectional view of the arc extinguishing device of a conventional shingle breaker. A vertical sectional view of an arc extinguishing device section showing an embodiment, FIG. 4 is a sectional view taken along the line - in FIG. 3, FIGS. FIGS. 7A, B, C, and D are side views showing other different embodiments of the arc guide plate used in the present invention. DESCRIPTION OF SYMBOLS 1... Outer box, 2, 3... Conductor, 5... Fixed arc contact, 6... Movable arc contact, 8, 9... Arc runner, 14... Arc barrier laminate, 16... Arc, 21, 22... Arc guide plate, 23...Wide gap part, 24...Tapered part, 25...Narrow gap part.

Claims (1)

[Claims] 1 A pair of movable and fixed arc contacts that can be approached and separated, an arc runner provided on one side of these arc contacts, and an arc barrier laminate provided on the opposite side of the arc runner from the arc contact. , in the shingle breaker comprising the pair of arc contacts and an arc guide plate provided with the arc cranker in between, the arc guide plate has a wide gap formed in the vicinity of the fixed arc contact. , from this wide gap part through a tapered gap part that gradually decreases to become a narrow gap part in most other areas, and when the pair of arc contacts are separated, the wide gap part is configured such that when the pair of arc contacts are separated, the arc contact A breaker characterized in that the movable arc contactor is moved to a distance within the range where arcing does not occur in parts other than the contactor.