JPH1012117A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict concentration of a heavy current arc generated in the even of short-circuit accidents, reduce wear and tear of a contact point, and enhance breaker performance by setting a bulkhead formed of an insulation material between flat plate conductors of a movable contact. SOLUTION: A bulkhead 10 set intermediate between flat plate conductor 4a and 4b separates portions of movable contact points 3a and 3b every phase. When a movable contact 4 is opened and released, an arc 20 generated from the movable contact points 3a an 3b is separated every movable contact points 3a and 3b by means oaf the bulkhead 10. Therefore, even in the case of a heavy current arc 20 such as short-circuit accidents as well as small-current, the arc 20 is separated every movable contact points 3a and 3b, respectively, without concentration at the movable contact points 3a and 3b. By this separation, expansion of the arc sectional area is restricted, the arc 20 is cooled by means of the bulkhead 10, and the arc voltage can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker having a movable contact formed by arranging a plurality of flat conductors in parallel for each phase, and more particularly to an improvement in breaking performance.

[0002]

2. Description of the Related Art FIG. 9 is a front view showing only one phase of a movable contact, a fixed contact and an arc extinguishing device of a conventional circuit breaker disclosed in Japanese Patent Application Laid-Open No. 5-54786. It is. FIG. 10 is a side view thereof. In the figure, 1
Is a fixed contact, 2 is a fixed contact fixed to the fixed contact,
3a and 3b are movable contacts fixed to the movable contact 4. The movable contact 4 in this case is formed by two plate conductors 4a and 4b extending substantially in parallel, and the movable contact 3a is fixed to one plate conductor 4a and the other plate conductor 4a.
The movable contact 3b is fixed to b. 5 is a movable contact 4
Is a support shaft for supporting the opening and closing operation. 6
Is an arc-extinguishing device, in which a plurality of arc-extinguishing plates 6a formed of a magnetic metal plate in a substantially U shape are held at predetermined intervals by arc-extinguishing side plates 6b formed of an insulating material. . Reference numeral 7 denotes an arc runner that causes an arc generated between the fixed contact 2 and the movable contact 3 (3a, 3b) to travel toward the arc extinguishing device 6.

In FIGS. 9 and 10, the load circuit can be energized while the fixed contact 2 and the movable contact 3 (3a, 3b) are in contact with each other, but the current flowing from the fixed contact 1 is
It flows from the movable contact 3 (3a, 3b) via the fixed contact 2 to the flat conductors 4a, 4b in parallel. Fixed contact 2 while energized
When the movable contacts 3 (3a, 3b) are separated from each other,
3 (3a, 3b), an arc is generated, and at the same time, an arc voltage is generated. The generated arc travels along the arc runner 7 by the magnetic action of the arc extinguishing plate 6a, is extended toward the arc extinguishing device 6, and the arc voltage is increased. The arc is cooled and extinguished by the arc extinguishing plate 6a.

[0004] FIG. 11 is a perspective view showing an opened state of the movable contact 4 having the above structure together with the arc 20 generated. In the separated state, when a large current is cut off, the arcs 20 generated from the movable contacts 3a and 3b cannot be independent of each other, and become a thick arc column as shown in the figure. In addition, even in the case of a thin arc 20 having a small current, the two arcs are currents in the same direction, so that the two arcs are attracted to each other by an electromagnetic force, so that a single thick arc 20 may be formed.

[0005]

As described above, the movable contact 4 formed by the two or more flat conductors 4a and 4b.
When a large current such as a short-circuit current is interrupted in the circuit breaker having the above, the cross-sectional area of the arc 20 tends to increase and the contact wear tends to increase. Further, as described above, when the arcs 20 generated from the movable contacts 3a and 3b are gathered and the cross section of the arc is enlarged, it is difficult to reduce the cross-sectional area of the subsequent high-current arc 20. The arc 20 having a large cross section is hard to be magnetically driven, and
Even if the arc extinguishing device 6 was used, it was not easy to improve the breaking performance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. A first object of the present invention is to suppress the congestion of a large current arc generated in a short circuit accident or the like, thereby reducing the consumption of contacts. And a circuit breaker having a high breaking performance. A second object is to provide a structure for suppressing the gathering of a large current arc, which can be easily installed using existing components.

[0007]

In a circuit breaker according to the present invention, a plurality of flat conductors are arranged in parallel for each phase and a movable contact is provided at one end of each flat conductor. A partition made of an insulating material is provided between the flat conductors of the movable contact so as to isolate the movable contact portion.

Further, a partition wall provided between the plate conductors of the movable contact is integrated with the arc extinguishing device.

Further, a pressure reflector is provided so as to surround the outer periphery of the fixed contact, and a partition wall provided between the flat conductors of the movable contact is formed integrally with the pressure reflector.

Further, the fixed contact of the fixed contact for one phase is divided into at least two corresponding to the movable contacts arranged in parallel.

[0011] Furthermore, in one in which the fixed contact for one phase is divided into at least two corresponding to the movable contact,
An isolation groove is provided between the divided fixed contacts.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a front view showing only one phase of a movable contact, a fixed contact, and an arc extinguishing device of a circuit breaker. is there. FIG. 2 is a side view showing a part of the arc extinguishing device cut away in the configuration of FIG. In the figure, 1 is a fixed contact, 2 is a fixed contact fixed to the fixed contact, 3
Reference numerals a and 3b denote movable contacts fixed to the movable contact 4.
The movable contact 4 in this case is formed by two plate conductors 4a and 4b extending substantially in parallel, the movable contact 3a is fixed to one plate conductor 4a, and the movable contact 3b is fixed to the other plate conductor 4b. Is fixed. Reference numeral 5 denotes a support shaft for supporting the movable contact 4 so that the movable contact 4 can be opened and closed. Reference numeral 6 denotes an arc extinguishing device, which holds a plurality of arc extinguishing plates 6a formed of a magnetic metal plate in a substantially U shape at predetermined intervals by arc extinguishing side plates 6b formed of an insulating material. is there. 7
Is an arc runner that causes an arc generated between the fixed contact 2 and the movable contact 3 (3a, 3b) to travel toward the arc extinguishing device 6. These are the same as the configurations shown in the section of the prior art.

Reference numeral 10 denotes a partition wall provided between the flat conductors 4a and 4b so as to isolate the movable contacts 3a and 3b for each phase. The partition 10 is made of an insulating material having high heat resistance among inorganic materials such as ceramics or organic materials such as thermosetting synthetic resins. Although the configuration for installation is not shown,
For example, it is held by a housing (not shown) of the circuit breaker.

FIG. 3 is a perspective view showing a state in which the movable contact 4 having the above structure is opened, together with the generated arc 20. In the separated state, the arc 20 generated from the movable contacts 3a, 3b is separated by the partition 10 into each movable contact 3a, 3b. Therefore, not only the small current but also the arc 20 having a large current such as a short-circuit accident, the arc 20 does not converge on each movable contact 3a, 3b without being concentrated on one movable contact 3a, 3b. Is separated into By this separation, the arc 20 is cooled by the partition walls 10 while the arc cross-sectional area is prevented from being enlarged, so that the arc voltage can be increased. In addition, since the arc cross-sectional area is small, the arc can be easily driven by the magnetic action of the arc extinguishing device 6, and the arc can be extinguished easily by extending the arc length. Further, since the arc current itself can be reduced, contact wear is reduced.
The shut-off performance is improved by a simple configuration of simply installing the.

Embodiment 2 FIG. 4 shows a second embodiment of the present invention. The figure is an exploded perspective view of the arc extinguishing device 6. The arc extinguishing device 6 corresponds to the arc extinguishing device 6 shown in FIGS. The fixed contact 1 and the movable contact 4 are the same as those in FIGS. In the figure, 6a is a well-known arc-extinguishing plate, and 6b is an arc-extinguishing side plate that holds the arc-extinguishing plate 6. Reference numeral 10 denotes a flat conductor 4 so as to isolate the movable contacts 3a and 3b for each phase.
It is a partition installed in the middle of a and 4b. This partition 10
Is made of, for example, an insulating material such as ceramic or thermosetting synthetic resin. The partition 10a is provided between the plate conductors 4a and 4b. Partition 1
0a, the portion of the holding portion 10b formed perpendicular to the
The portion of the fitting portion 10c at the tip is the square hole 6 of the arc-extinguishing side plate 6b.
c. By this fitting, the partition 10 is held by the arc-extinguishing side plate 6b together with the arc-extinguishing plate 6a. According to this configuration, since the partition 10 is automatically installed by incorporating the arc extinguishing device 6, a circuit breaker with excellent assembling workability can be obtained.

Embodiment 3 FIG. 5 shows a third embodiment of the present invention, and is a perspective view showing a fixed contact 1 and a movable contact 4. In the figure, reference numeral 8 denotes a pressure reflector provided so as to surround the outer periphery of the fixed contact 2. The pressure reflector 8 is similar to the pressure reflector disclosed in Japanese Patent Publication No. 2-7134 or Japanese Utility Model Publication No. 2-18515, for example, an inorganic insulating material such as ceramic or a thermosetting synthetic material. It is formed of an organic insulating material such as a resin. 8a is a partition, and the pressure reflector 8
The partition 8a is formed integrally with the flat conductors 4a,
4b. In the above configuration, since the partition 8a is formed integrally with the pressure reflector 8, the partition 8a can be installed without increasing the number of components. Therefore, manufacturing and assembling operations of parts are facilitated. The pressure reflector 8 functions to suppress the arc cross-sectional area from expanding as described in the above-mentioned publication. Further, the generated arc is applied to each movable contact 3 by the partition 8a.
Since separation is performed for each of a and 3b, it works to suppress the expansion of the arc cross-sectional area. Therefore, a circuit breaker with further improved breaking performance due to the synergistic effect can be obtained.

Embodiment 4 FIG. 6 shows a fourth embodiment of the present invention, and is a perspective view showing a fixed contact 1 and a movable contact 4. In the figure, 2a and 2b are small fixed contacts divided so as to correspond to the movable contacts 3a and 3b. In this way, the fixed contact 2 is divided and fixed to 2a and 2b, and the partition wall 10 made of an insulating material as shown in the first embodiment is provided. According to this configuration, the amount of expensive contact material used is reduced, so that an increase in cost can be suppressed. Therefore, the circuit breaker is advantageous in manufacturing and can completely separate the arc, so that a circuit breaker with improved breaking performance can be obtained as in the above embodiment.

Embodiment 5 FIG. 7 shows a fifth embodiment of the present invention, and is a perspective view showing a fixed contact 1 and a movable contact 4. In the figure, 1c is a fixed contact 1
, Which are cut off and separated between the edge portions 1a and 1b for fixing the fixed contacts 2a and 2b. According to this configuration, the partition wall 1 extends to the isolation groove 1c.
Since 0 can be inserted and installed, arc separation is more complete, and a circuit breaker with improved breaking performance as in the above embodiment can be obtained.

By providing the isolation groove 1c, it is possible to insert and install the partition 10 from below the fixed contact 1. For example, a housing (shown in FIG. The partition 10 can be attached to the partition 10 or a part of a housing (not shown) can be used as the partition 10, so that the configuration and the arrangement of the partition 10 can be simplified.

Further, even if the fixed contact 1 has a U-shaped bent portion 1d as shown in FIG. 8, this embodiment can be applied, and the same configuration and effect can be obtained. can get.

[0021]

Since the present invention is configured as described above, it has the following effects.

Since a partition wall made of an insulating material is provided between the flat conductors of the movable contact so as to isolate the movable contact portion for each phase, the arc at the time of interrupting a large current is separated. As a result, the circuit breaker with excellent breaking performance can be obtained.

Further, a partition wall provided between the flat conductors is
If it is installed integrally with the arc extinguishing device, the partition is automatically installed, so that a circuit breaker having excellent assembling workability can be obtained.

Further, a partition wall provided between the flat conductors is
The one that is formed and installed integrally with the pressure reflector surrounding the outer periphery of the fixed contact has fewer parts and the cross-sectional area of the arc is suppressed by the synergistic effect of the partition wall and the pressure reflector, so the blocking performance is even better. Circuit breaker is obtained.

Further, the one in which the fixed contact for one phase is divided into at least two parts corresponding to the movable contact,
Since the amount of expensive contact material used is reduced, an increase in cost can be suppressed.

Further, in the case where the isolation groove is provided between the divided fixed contacts, the partition can be inserted and installed up to the isolation groove portion, so that the arc is more completely separated. Further, the shape and arrangement of the partition can be made simple such that the partition can be inserted from below the fixed contact.

[Brief description of the drawings]

FIG. 1 is a front view showing a contact portion of a circuit breaker of the present invention.

FIG. 2 is a side view showing a contact portion of the circuit breaker of the present invention.

FIG. 3 is a perspective view showing a state where a contact portion of the present invention is separated.

FIG. 4 is an exploded perspective view showing an arc extinguishing device according to a second embodiment.

FIG. 5 is a perspective view showing a contact portion according to a third embodiment.

FIG. 6 is a perspective view showing a contact portion according to a fourth embodiment.

FIG. 7 is a perspective view showing a contact portion according to a fifth embodiment.

FIG. 8 is a perspective view showing an application example of the fifth embodiment.

FIG. 9 is a front view showing a contact portion of a conventional circuit breaker.

FIG. 10 is a side view showing a contact portion of a conventional circuit breaker.

FIG. 11 is a perspective view showing a state where a conventional contact portion is separated.

[Explanation of symbols]

Reference Signs List 1 fixed contact, 1c isolation groove, 2, 2a, 2b fixed contact, 3, 3a, 3b movable contact, 4 movable contact, 4
a, 4b flat conductor, 5 support shaft, 6 arc extinguishing device, 6a
Arc extinguishing plate, 7 arcrunner, 8 pressure reflector, 10 partition, 20 arc.

Claims (5)

[Claims] 1. A fixed contact having a fixed contact fixed to one end thereof, and a plurality of flat conductors arranged in parallel with a movable contact at one end of each flat conductor, capable of opening and closing the fixed contact. Circuit breaker provided for each phase with a movable contact rotatably supported as described above, and an arc extinguishing device for extinguishing an arc generated between the fixed contact and the movable contact when the movable contact is opened. 3. The circuit breaker according to claim 1, wherein a partition made of an insulating material is provided between the plate conductors of the movable contact so as to isolate a movable contact portion for each phase. 2. The circuit breaker according to claim 1, wherein the partition wall provided between the plate conductors of the movable contact is integrated with the arc extinguishing device. 3. A pressure reflector is provided so as to surround the outer periphery of the fixed contact, and a partition wall provided between the flat conductors of the movable contact is formed integrally with the pressure reflector. The circuit breaker according to claim 1. 4. The circuit according to claim 1, wherein the fixed contact of the fixed contact for one phase is divided into at least two corresponding to a plurality of movable contacts. Circuit breaker. 5. The circuit breaker according to claim 4, wherein an isolation groove is provided between the divided fixed contacts of the fixed contact.