JPH01122539A - Circuit breaker - Google Patents

Abstract

PURPOSE:To facilitate the breaking of the high voltage by arranging the arc extinguishing plate of an arc extinguishing device nearest to a movable contact piece on the side apart from a fixed contact piece than the tip of the movable contact piece at the separated position and arranging other arc extinguishing plates nearer to the fixed contact piece as they are separated from the movable contact piece. CONSTITUTION:When a movable contact piece 7 is separated from a fixed contact piece 4 and an are A is generated across both contact pieces, at least the arc extinguishing plate 331 nearest to the contact piece 7 is arranged on the contact piece 4 side than the tip of the contact piece 7 at the separated position, the arc A is extended to the contact piece 7 side, i.e., upward, and extended by the subsequent arc extinguishing plates 332 toward the arc extinguishing plates 332 via the electromagnetic force. Since the arc extinguishing plates 332 are arranged to approach the contact piece 4 in sequence from the arc extinguishing plate 331 nearest to the movable contact piece 7 toward the first arc extinguishing device 13, the arc A enters the back portion of the arc extinguishing plates 332 as it approaches the device 13 and is divided by the arc extinguishing plates 332. The high voltage can be easily broken by the extension and division of the arc A accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to circuit breakers, and in particular to improvements in their arc extinguishing ability.

[Prior Art] Figures 7 to 9 are cross-sectional views showing conventional circuit breakers.
Each shows a different operating state. In the figure,
(1) is a cover, (2) is a base, and the cover (1) and the base (2) constitute a housing (3). (4) is a fixed contact, which has a fixed conductor (5), has a fixed contact (6) at one end, and has a terminal portion at the other end to be connected to an external conductor (not shown). ing. (7) is a movable contact, which has a movable conductor (8) and a fixed contact (6) at one end.
It has a movable contact (9) facing the. (10) is a movable contact device, and (11) is a movable contact arm, which is fixed to a crossbar (12) so that each pole can be opened and closed at the same time. (13) is an arc extinguishing device, and an arc extinguishing plate (14) is held by a side plate (15). (16) is a toggle link mechanism, which is composed of an upper link (17) and a lower link (18). One end of the upper link (17) is Freddle (
19), and the other end is connected to the negative end of the lower link (18) by shafts (20) and (21), respectively. In addition,
The other end of the lower link (18) is the movable contact device (10).
is connected to the movable arm (11) of. Reference numeral (22) is an up/down operating handle, and reference numeral (23) is an operating spring, which is stretched between the shaft (21) of the toggle link mechanism (16) and the operating handle (22). (24) is a thermal type trip device, (
25) is a fixed core of the electromagnetic tripping mechanism, and the fixed core (25) is magnetized by the current flowing through the bimetal (26) of the thermal tripping device (24), thereby causing the movable core (2
7) is drawn into the fixed iron core (25).

Then, when an overload current flows, the bimetal (26) moves the trip bar (28) counterclockwise, and when a large current such as a short circuit current flows, the movable iron core (27), which is attracted to the fixed iron core (25), moves the trip bar (28) counterclockwise. It is designed to rotate. (29) is a latch whose one end is locked to the trip bar (28) and the other end is locked to the fredle (19).

When the operating handle (22) is tilted to the closing position with the flettle (19) locked to the latch (29), the toggle link mechanism (16) will extend and the shaft (21) will move to the flettle (19).
The movable contact (9) is joined to the fixed contact (6). This state is shown in FIG.

Next, when the operation handle (22) is tilted to the open position, the toggle link mechanism (16) is bent, the movable contact (9) is separated from the fixed contact (6), and the movable child arm (11) is moved to the flettle shaft. (30) is locked. This state is shown in FIG.

Furthermore, when an overcurrent flows through the circuit in the closed circuit state shown in FIG.
) is disengaged, and the fredle (19) is moved to the fredle shaft (
30) in the clockwise direction, and the stopper shaft (31)
is locked. At this time, since the connection point between the fredle (19) and the upper link (17) crosses the line of action of the operating spring (23), the toggle link mechanism (16) is bent by the spring force of the operating spring (23), and the crossbar is bent. - (12) performs automatic shutoff in conjunction with each pole.

This state is shown in FIG.

Next, the behavior of the arc that occurs when the circuit breaker cuts off the current will be explained.

Now, when the movable contact (9) and the fixed contact (6) are in contact, the power is transferred from the power source side to the fixed conductor (5).
), fixed contact (6), movable contact (9) and movable conductor (8
) is sequentially supplied to the load side. In this state, if a large current such as a cargo loading current or a short-circuit current flows through this circuit, the movable contact (9) will switch to the fixed contact (6) as described above.
separated from At this time, the fixed and movable contacts (6
) and (9), and an arc voltage is generated between the fixed and movable contacts (6) and (9). This arc voltage is transferred from the fixed contact (6) to the movable contact (9).
As the separation distance increases, the arc (A) rises, and at the same time, the arc (A) is drawn toward the arc extinguishing plate (14) by magnetic force and extends, so it further rises.

In this way, the arc current reaches a current zero point, the arc is extinguished, and the interruption is completed.

[Problems to be Solved by the Invention] The conventional circuit breaker is constructed as described above, and a single arc extinguishing device is provided to extend the arc by simply drawing the arc toward this arc extinguishing device. Since the attempt is to increase the arc voltage, there is a problem in that there is a limit to the increase in arc voltage, and therefore there is a limit to the improvement in arc extinguishing performance.

This invention was made in order to solve the problems of the conventional one, and is capable of increasing the arc voltage than the conventional one equipped with a single arc extinguishing device, and therefore has improved circuit breaker performance. It is a verbal promise to provide a vessel.

[Means for Solving the Problems] The circuit breaker according to the present invention has a conventional arc extinguishing device (first arc extinguishing device) disposed facing both contacts, and a movable contact in the open position. A second arc extinguishing device consisting of a plurality of arc extinguishing plates is provided between the second arc extinguishing device and the one closest to the movable contact in the open position. The other arc extinguishing plates of the second arc extinguishing device are disposed on the side away from the fixed contact from the tip, and the other arc extinguishing plates are sequentially attached to the fixed contact from the one closest to the movable contact toward the first arc extinguishing device. They are arranged so that they are close together.

[Effect]

In this invention, among the arc extinguishing plates of the second arc extinguishing device, at least the one closest to the movable contact is disposed on the side opposite to the fixed contact from the tip of the movable contact at the time of opening. The other arc extinguishing plates of the second arc extinguishing device are arranged so as to approach the fixed contact one after another toward the first arc extinguishing device, so the arc is extinguished by these extinguishing plates. Divided by arc plates.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a partial cross-sectional side view of the main part of the embodiment,
Parts that are the same as those in the prior art are given the same reference numerals and their explanations will be omitted.

In the figure, (32) is a second arc extinguishing device provided between a first arc extinguishing device (13), which is a conventional arc extinguishing device, and a movable contact (7) in the open position. It consists of a plurality of flat arc-extinguishing plates (33), and these arc-extinguishing plates (33) are supported by side plates (15). (34) is an arc runner that guides the firing point of the arc (A) on the fixed contact (4) side to the first arc extinguishing device (13).

Among the arc extinguishing plates (33) of the second arc extinguishing device (32), the one (331) closest to the movable contact (7) is fixed from the tip of the movable contact (7) in the open position as shown in the figure. A second arc extinguishing device (3) is disposed on the side away from the contact (4), that is, above the tip of the movable contact (7) in FIG.
The other arc extinguishing plate (332) in 2) is the movable contactor (7).
from the one closest to (331) to the first arc extinguishing device (13)
They are arranged so as to approach the fixed contact (4) one after another.

Next, the operation will be explained. When the movable contact (7) separates from the fixed contact (4) and an arc (A) is generated between the two contacts (4) and (7), at least the movable contact (
The arc extinguishing plate (331) closest to the arc (A) is disposed on the side opposite to the fixed contact (4) from the tip of the movable contact (7) in the open position. The firing point on the 7) side quickly moves to the tip of the movable contact (7) due to the electromagnetic driving force, and the arc (A) moves towards the opposite fixed contact (7).
7) side, that is, upward, and the arc (A) is also extended by the following arc extinguishing plate (332).
) is driven and stretched by an electromagnetic driving force. Further, the other arc extinguishing plates (332) are arranged from the arc extinguishing plate (331) closest to the movable contactor (7) to the first arc extinguishing device (13).
Since the arc (A) is arranged so as to approach the fixed contact (4) sequentially toward the first arc extinguishing device (13), it enters the deep part of the arc extinguishing plate (332) and these It is divided by an arc extinguishing plate (332). Depending on how close the arc extinguishing plate (331) is placed to the tip of the movable contact (7) in the open position, the arc (A) may already be separated from the arc extinguishing plate (331). It's possible.

As mentioned above, the arc (
Due to the extension and division of A), the arc voltage becomes dramatically larger than that of the conventional first arc extinguishing device (13) L, or the one without it, and the arc extinguishing ability is greatly improved.Furthermore, The second arc extinguishing device (32) stretches the arc (A) far away from between the contacts (6) and (9), so the area near the contacts (6) and (9) where dielectric breakdown is most likely to occur Insulation recovery in the atmosphere also progresses rapidly, and as a result, dielectric breakdown after the current zero point is less likely to occur.This also improves the arc extinguishing ability, making it easier to interrupt high voltages.Note that if the arc (A) is fixed Rapidly moving the firing point on the contact (4) side toward the first arc extinguishing device (13) improves the insulation recovery power and the arc extinguishing force of the second arc extinguishing device (13). It is useful for the effective use of fixed contacts (
4) It is effective to provide an arc runner (34).

The main parts of another embodiment of the invention are shown in a partially sectional side view in FIG. This embodiment differs from the one in FIG. 1 in that an arc horn (801) is provided at the tip of the movable contact (7), which in its open position is directed toward the nearest arc extinguishing plate (331). It is a point. Providing such an arc horn (801) makes it easier to attract the arc (A) to the second arc extinguishing device (32). In addition, in this embodiment, the arc extinguishing plate (3) of the second arc extinguishing device (32)
3) ' is a U-shaped recess (33) as shown in Figure 3.
3), or the arc-extinguishing plate itself having such a shape is known. Alternatively, as shown in FIG. 4, an arc-extinguishing plate (33) having a slit (334) at the back of the U-shaped recess (333) (this shape is also known) may be used.

Furthermore, in the embodiment, the arc extinguishing plate (
33) are provided perpendicularly to the arc extinguishing plate (14) of the first arc extinguishing device (13), and as shown in FIG. 13) Arc-extinguishing plate (
14), or as shown in FIG. 6, all the arc extinguishing plates (33) may be arranged as a first arc extinguishing device facing the arc extinguishing plates (14). By using an extremely simple configuration in which a second arc extinguishing device is provided in a predetermined manner between the movable contact in the open position, it is possible not only to increase the arc voltage but also to quickly recover the insulation of the atmosphere near both contacts. Since this is carried out in the following manner, the arc extinguishing performance is dramatically improved, and the effect of facilitating high voltage interruption can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional side view of the main part of one embodiment of the present invention, FIG. 2 is a partial sectional side view of the main part of another embodiment of the invention, and FIGS. 3 and 4 are the main parts of the second embodiment. Figures 5 and 6 are partial cross-sectional side views of main parts of still another embodiment of the present invention;
7 to 9 are partial cross-sectional side views of a conventional circuit breaker, each showing a different operating state.
In the figure, (4) is a fixed contact, (7) is a movable contact, (13) is a first arc extinguisher, (32) is a second arc extinguisher, and (33) is a second arc extinguisher. The arc extinguishing plate (331) of the device is the one closest to the movable contact among the arc extinguishing plates (33), (3
32) is another arc extinguishing plate, (801) is an arc horn, (A
) is an arc. Note that the same reference numerals in each figure indicate the same or equivalent parts. Agent Patent Attorney Masuo Oiwa
(Tohe Q qco agreement 6 Figure 7 Figure 7゛'Word mushroom:;

Claims (2)

[Claims] (1) A fixed contact, a movable contact that can open and close with respect to the fixed contact, and a movable contact that is disposed opposite to these contacts and that opens and closes when the movable contact is separated from the fixed contact. In the circuit breaker equipped with a first arc extinguishing device for extinguishing an arc generated during A second arc extinguishing device is provided, and the one closest to the movable contact among the arc extinguishing plates of the second arc extinguishing device is arranged on the side farther from the fixed contact than the tip of the movable contact in the open position. The other arc extinguishing plates of the second arc extinguishing device are arranged so as to approach the fixed contact in sequence from the one closest to the movable contact toward the first arc extinguishing device. circuit breaker. (2) The circuit according to claim 1, wherein the movable contact has an arc horn at its tip that is directed toward the arc extinguishing plate of the second arc extinguishing device closest to the movable contact in its open position. Breaker.