JP6007135B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker having a current interruption structure.

  Conventionally, in a circuit breaker having a fixed contact and a movable contact, when interrupting current, the movable contact of the movable contact is opened with respect to the fixed contact of the fixed contact, and the contact between the fixed contact and the movable contact The arc generated between them is cut off by cooling with an arc extinguishing device. At that time, by attaching an arc runner formed of a metal plate near the fixed contact so that the arc generated between the contacts does not stagnate on the contact, the arc is quickly guided to the arc extinguishing device and the wear of the fixed contact due to the arc is reduced. ing. Such a structure and function of the arc runner are disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 9-171759) and the like.

  Patent Document 2 discloses a magnetic body composed of an arc extinguishing core having a U-shaped horizontal cross section and a substrate extending horizontally therefrom, for the purpose of simplifying the structure of the arc extinguishing device and making it difficult to be damaged by the arc. A technique is disclosed in which an arc extinguishing device is configured by being fixed to a U-shaped folded portion of a stationary contact via a substrate. The substrate can be integrally formed with a magnetic driving core for increasing the magnetic driving force against the arc and an arc horn for guiding the arc to the arc extinguishing core.

  Patent Document 3 aims to provide an arc extinguishing device for a circuit breaker that suppresses the arc current and shortens the time required for extinguishing the arc, and has a fixed contact on the lower surface side of the contact support piece provided on the upper surface. The main piece of the yoke is arranged, the leg pieces located on both sides of the fixed contact are provided on both side edges of the main piece of the yoke, and the main piece of the yoke is provided with the contact support piece at the tip side of the contact support piece. There is disclosed a device in which an arc running piece protruding upward from the upper surface is provided.

  In Patent Document 4, in order to increase the arc driving force of the arc runner, the arc runner of the magnetic plate provided on the lower surface of the upper leg portion of the U-shaped fixed contact base of the fixed contact is formed in a U shape having side plates on the left and right The arc generated on the stationary contact when the current is interrupted immediately moves to the side plate higher than the stationary contact and is opposite to the stationary contact by the magnetic driving force acting on the arc based on the magnetic flux of the current flowing through the upper leg. It is disclosed that it is driven to the side and runs along the edge of the side plate and enters the arc extinguishing grid at its tip to be extinguished.

JP-A-9-171759 JP-A-7-320624 JP-A-9-17316 JP 11-25834 A

  The breaker's arc runner according to the prior art has the effect of inducing the arc to the arc extinguishing device, while the arc generated when interrupting a large current passes through the arc heat and damages the function. was there. Further, when interrupting a small DC current, the magnetic field for moving the arc becomes weak and there is no current zero point, so that there is a problem that the arc is stuck on the contact and it becomes difficult to interrupt.

  The present invention has been made in view of the above problems, and provides a circuit breaker that improves the breaking performance by reducing arc heat damage and preventing the arc from sticking to the contacts. With the goal.

In order to solve the above problems, the circuit breaker of the present invention is provided with a movable contact and a fixed contact for opening and closing a main circuit current, a movable contact provided on the movable contact, and a fixed contact. An arc extinguishing chamber in which an arc extinguishing device is disposed for storing a contact with the fixed contact and extinguishing an arc generated when the current is interrupted, and an open / close mechanism for opening and closing the movable contact with respect to the fixed contact A circuit breaker having an overcurrent tripping portion for detecting an overcurrent of the main circuit and opening the contact, and having a U-shape covering the lower surface and both side surfaces of the fixed contact to which the fixed contact is attached An arc runner is provided, and an insulating member is provided inside the arc runner so as to cover the fixed contact from both side surfaces. The arc runner includes a side wall covering a side surface of the fixed contact, and the arc extinguishing device rather than the fixed contact. Extend to the side And a arc running path formed by opposed Te, the arc runway, and forming a narrower gap than the width of the fixed contact.

According to the present invention, it is possible to provide a circuit breaker that can reduce damage due to arc heat, and that prevents the arc from sticking to the contact point, thereby improving the breaking performance. In addition, the gap of the arc runner's arc travel path reduces the area exposed to the arc and has a thick shape, thus reducing the damage caused by the arc current of large current while maintaining the function of running the arc. be able to. Further, a portion where the arc runner is bent and faces each other with a gap acts so that a magnetic field generated in the gap draws the arc, and a force for driving the arc can be obtained even with a small current. As a result, even when a large current is interrupted, the arc travel path is not damaged by the thermal damage of the arc runner, and the interrupting performance can be improved by guiding the arc to the arc extinguishing device and extinguishing it even in a small current region. it can.
Thick shape: In the present invention, a steel plate is assumed as a material for forming the arc runner, and the shape obtained by normal pressing is generally larger in width than the plate thickness. In the present invention, this is used to make the end face of the plate visible from the contact side, so that the direction with a width wider than the plate thickness is the depth direction, and the shape is thicker as viewed from the contact side.

It is a block diagram which shows the structure of the circuit breaker of Example 1 which concerns on this invention. It is a perspective view which shows the principal part of the circuit breaker of Example 1 which concerns on this invention. It is a perspective view which shows the principal part of the circuit breaker of Example 2 which concerns on this invention. It is a perspective view which shows the principal part of the circuit breaker of Example 3 which concerns on this invention. It is a perspective view which shows the principal part of the circuit breaker of Example 4 which concerns on this invention.

  Examples 1 to 4 as embodiments of the present invention will be described below with reference to the drawings.

  Embodiment 1 of the present invention will be described below with reference to FIGS.

  FIG. 1, which is the best mode, is a configuration diagram illustrating the structure of the circuit breaker 1 according to the first embodiment. The circuit breaker 1 of the present invention is for opening and closing the movable contact 15 with respect to the fixed contact 13, the arc extinguishing device 14, the movable contact 15, and the fixed contact 13 in the mold case 11 and the cover 12. An open / close mechanism 16, an overcurrent tripping portion (not shown), and the like are configured, and the fixed contact 13 is integrally provided with an arc runner 17 formed of a magnetic material such as a steel plate.

  The arcrunner 17 is formed in a U-shaped cross section, and the portion covering the both side surfaces of the fixed contact base 31 positioned on the distal end side of the fixed contact 13 is on the arc extinguishing device 14 side (left side in FIG. 1, FIG. 2). The arc travel path 17a is formed by extending to the left rear side. When the circuit breaker 1 cuts off the current, an arc 18 is generated between the fixed contact 22 attached to the fixed contact 22 of the fixed contact 13 and the movable contact 19 of the movable contact 15. The arc 18 is effectively guided by the extended arc travel path 17a, reaches the arc extinguishing device 14, is cooled and divided, and disappears.

FIG. 2 is a perspective view illustrating a stationary contact 13 that is a main part of the circuit breaker 1 according to the first embodiment. The fixed contact 13 will be further described with reference to FIG. Two partition plates 20 (only one is visible in FIG. 1) that are insulating members partition the arc extinguishing chamber 35 in which the arc extinguishing device 14 is arranged. A fixed contact 22 is attached to a fixed contact base 31 positioned between the partition plates 20, and an arc runner 17 is disposed in order to generate an arc in the vicinity thereof when the pole is opened.

The arcrunner 17 is formed in a U shape so as to cover the lower surface and the side surface of the portion of the fixed contact base 31 to which the fixed contact 22 is attached, and a rising portion is formed on both sides of the fixed contact base 31. An air gap is provided between the side wall 17b of the arc runner 17 and the fixed contact base 31, and an insulating member 34 that is higher than the side wall 17b of the arc runner 17 and higher than the contact between the movable contact 19 and the fixed contact 22 is provided in this air gap. Inserting. By this inserted insulating member 34, the side wall 17 b of the arc runner 17 and the side surface of the fixed contact 22 are covered and the portion covering the side surface of the fixed contact 22 of the arc runner 17 and the contact between the fixed contact 22 and the movable contact 19 are formed. The space is partitioned so that the arc 18 can be effectively guided to the arc extinguishing device 14 at the time of opening.

  Further, the side wall 17b of the arc runner 17 extends in the direction of the terminal 31a of the fixed contact base 31 where the arc extinguishing device 14 is located, and the extended portion is bent inward from both sides, whereby the width dimension is increased. The arc running path 17a having a narrow gap is formed facing each other. As shown in FIG. 2, the insulating member 34 is not provided in the arc travel path 17a, and the width of the gap of the arc travel path 17a is narrow (below the width of the fixed contact 22 and fixed contact). The magnetic flux can be increased by setting it to about 1/2 to 1/5 of the width of 22. In this embodiment, the arc runner 17 is lower than the contact between the fixed contact 22 and the movable contact 19.

  By forming the arc runner 17 as described above, the gap of the arc travel path 17a has a smaller area than the fixed contact 22 side and has a thick shape, so even when exposed to a large current arc. The arc running path 17a is not melted by arc heat and its function is not lost, and the circuit breaker 1 with high reliability can be provided. Further, a magnetic flux generated around the current path of the fixed contact base 31 passes through the arc runner 17, but a part of this magnetic flux is between the side walls 17b of the arc runner 17 on both sides and from the gap of the arc travel path 17a. An arc driving magnetic flux is generated in the vicinity of the fixed contact 22. In particular, in the vicinity of the arc travel path 17a in which the gap is narrowed, the magnetic resistance is lower than that on the fixed contact 22 and the magnetic flux is increased. It is possible to improve the breaking ability in a high current and a small current region of AC low power factor. If only the effect of preventing the functional loss due to the melting of the arc travel path 17a described above is obtained, the arc runner 17 may be a non-magnetic material, and the arc travel path 17a may be only on one side. Further, it is not necessary to bend the arc travel path 17a in the center direction.

  Further, the side wall 17b of the arc runner 17 is covered with the insulating member 34, thereby preventing the arc from moving to the side wall 17b of the arc runner 17 and damaging the arc runner 17. Further, when using a technique in which a polymer material is disposed in the vicinity of the contact of the fixed contact 22 and the arc is narrowed down by generating a decomposition gas by arc heat to improve the interruption performance of a high-current arc, the insulating member 34 is appropriately used. By using the polymer material, the means for fixing the polymer material in the vicinity of the contact can be simplified, and the interruption performance can be easily improved.

  The insulating member 34 formed higher than the height of the side wall portion (side wall 17b) of the arcrunner 17 is more effective by being inserted into the cut portion of the arc partition wall surface (partition plate 20) of the arc extinguishing device 14. Arc extinguishing ability can be achieved.

  FIG. 3 is a perspective view showing the fixed contact 113 according to the second embodiment. Although the insulating member 34 according to the first embodiment is not provided, the fixed contact 13 is replaced with the fixed contact 13 according to the first embodiment shown in FIG. This is a case where the fixed contact 113 of the second embodiment is applied. In addition, about the structure etc. which are common in Example 1, the same code | symbol is used and it demonstrates below.

  As shown in FIG. 3, in the fixed contact 113 of Example 2, the fixed contact 22 is attached to the fixed contact base 31, and the arc runner 17 formed of a magnetic material such as a steel plate is disposed in the vicinity thereof.

  The arcrunner 17 is U-shaped so as to cover the lower surface and the side surface of the fixed contact base 31 to which the fixed contact 22 is attached, and the side wall 17b of the arc runner 17 covering both side faces of the fixed contact base 31 is erased. The arc device 14 extends in the direction of the terminal 31a of the fixed contact base 31 with the arc device 14 to form an arc travel path 17a. And this part is made into the shape which bent toward the inner side from both sides, gave the space | gap, and faced each other.

  By forming the arc runner 17 as described above, the gap of the arc travel path 17a has a smaller area than the fixed contact 22 side and has a thick shape, so even when exposed to a large current arc. The arc running path 17a is not melted by arc heat and its function is not lost, and the circuit breaker 1 with high reliability can be provided. Further, a magnetic flux generated around the current path of the fixed contact base 31 passes through the arc runner 17, but a part of this magnetic flux is between the side walls 17b of the arc runner 17 on both sides and from the gap of the arc travel path 17a. An arc driving magnetic flux 24 is created in the vicinity of the fixed contact 22. In particular, in the vicinity of the arc travel path 17a in which the gap is narrowed, the magnetic resistance is lower than that on the fixed contact 22 and the magnetic flux is increased. It is possible to improve the breaking ability in a high current and a small current region of AC low power factor. If only the effect of preventing the functional loss due to the melting of the arc travel path 17a described above is obtained, the arc runner 17 may be a non-magnetic material, and the arc travel path 17a may be only on one side. Further, it is not necessary to bend the arc travel path 17a in the center direction.

  FIG. 4 is a perspective view showing the fixed contact 213 according to the third embodiment, in which the fixed contact 213 according to the third embodiment is applied instead of the fixed contact 13 according to the first embodiment shown in FIG. In addition, about the structure etc. which are common in Example 1, the same code | symbol is used and it demonstrates below.

As shown in FIG. 4, the fixed contact 213 of the third embodiment basically has the same configuration as the fixed contact 13 of the first embodiment, but the movable contact 19 contacts the side wall 17 b of the arc runner 17. An insulating member 34 is formed integrally with the side wall 17b of the arc runner 17 so as to be higher than the side wall 17b, and the side surface of the arc runner 17 is covered with the insulating member 34. ing. By doing in this way, it becomes possible to prevent the side wall 17b of the arc runner 17 from being damaged by the arc heat even with a smaller width.
Narrower width: refers to the width of the side wall of the arc runner. In addition to the method of sandwiching the insulating member in the gap between the side wall and the fixed contact, the effect of preventing damage to the side wall can be obtained by covering the arc runner side wall with the insulating member from above.

  FIG. 5 is a perspective view showing the fixed contact 313 of the fourth embodiment, in which the fixed contact 313 of the fourth embodiment is applied instead of the fixed contact 13 of the first embodiment shown in FIG. In addition, about the structure etc. which are common in Example 1, the same code | symbol is used and it demonstrates below.

  As shown in FIG. 5, in the fixed contact 313 of the fourth embodiment, the fixed contact 22 is attached to the fixed contact base 31, and the arc runner 17 is disposed in the vicinity thereof. The arc runner 17 is formed in a U shape so as to cover the lower surface and the side surface of the portion of the fixed contact base 31 to which the fixed contact 22 is attached, and the side wall 17b of the arc runner 17 covering the side surface of the fixed contact base 31 is fixed contact The front end of the base 31 is bent inward from both sides, and the end faces are configured to face each other with a gap. According to this configuration, even when the space of the arc extinguishing chamber 35 is limited, the magnetic flux that guides the arc at the tip of the arc runner 17 to the arc extinguishing device 14 can be generated, and the current interruption capability can be enhanced. In the fixed contact 313 of the fourth embodiment, the insulating member 34 described in the first and third embodiments may be configured. By configuring the insulating member 34, the first and third embodiments are configured. The same effect can be obtained.

DESCRIPTION OF SYMBOLS 1 Circuit breaker 11 Mold case 12 Cover 13 Fixed contact 14 Arc-extinguishing device 15 Movable contact 16 Opening / closing mechanism part 17 Archer 17a Arc travel path 17b Side wall 18 Arc 19 Moving contact 20 Partition plate 22 Fixed contact 24 Arc drive magnetic flux 31 contact base 31a end child
3 4 Insulating member 35 Arc extinguishing chamber 113 Fixed contact 213 Fixed contact 313 Fixed contact

Claims (4)

A movable contact and a stationary contact for opening and closing the main circuit current;
An arc extinguishing chamber that houses a contact between a movable contact provided on the movable contact and a fixed contact provided on the fixed contact, and has an arc extinguishing device that extinguishes an arc generated when a current is interrupted,
An opening and closing mechanism for opening and closing the movable contact with respect to the fixed contact;
In a circuit breaker with an overcurrent tripping part that detects overcurrent in the main circuit and opens the contact,
A U-shaped arc runner that covers the lower surface and both side surfaces of the fixed contact of the portion to which the fixed contact is attached;
Inside the arc runner, an insulating member is provided so as to cover the fixed contact from both side surfaces ,
The arc runner includes a side wall that covers a side surface of the fixed contact, and an arc traveling path that extends from the fixed contact toward the arc-extinguishing device and faces each other, and the arc traveling path includes the fixed contact. A circuit breaker characterized by forming a gap narrower than the width dimension of the circuit breaker. The circuit breaker according to claim 1, the height of the side wall of the arc runner, formed lower than the contact height between the movable contact and the fixed contact,
And characterized in that the height of the insulating member inside said arc runner cover the side of the fixed contact, the higher form than the height of the side wall of the arc runner, covers and conceals the sides of the arc runner by the insulating member Circuit breaker to do. The circuit breaker according to claim 1, said insulating member which is formed higher than the height of said side wall of said arc runner is being configured to be inserted into the notch in the arc partition wall surface of the arc extinguishing device Feature circuit breaker. 4. The circuit breaker according to claim 1, wherein the arc runner is formed of a magnetic material, and the arc travel path of the arc runner is bent so as to face inward, and formed by a bent portion. A circuit breaker characterized in that a gap to be formed is formed to be equal to or smaller than a width of the fixed contact.

Images