JP5121608B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker such as a circuit breaker for a wiring or an earth leakage breaker, in an arc extinguishing chamber having an arc running conductor for transferring an arc to a plurality of arc extinguishing plates which are arc extinguishing devices, The present invention relates to a circuit breaker that can improve current limiting performance that suppresses overcurrent by improving arc maintenance performance in an arc extinguishing plate.

In recent years, due to the increase in capacity and space saving of low-voltage wiring facilities, wiring breakers, earth leakage circuit breakers, etc. are required to be reduced in outer dimensions. One of the issues in miniaturization is the improvement of current limiting performance that suppresses overcurrent. An arc extinguishing plate that draws and divides the arc generated between contacts when an overcurrent is interrupted, such as in an accident, and raises the arc voltage by generating an electrode drop voltage and cooling the arc to limit the current. It is one of the parts that influences, and it is important to maintain the arc continuously with the arc extinguishing plate. Improved current-limiting performance enables the arc energy to be processed in the arc-extinguishing chamber of the circuit breaker to be reduced, reducing the thermal and electromagnetic load on the components that make up the circuit breaker and enabling downsizing. .
In the conventional circuit breaker, the arc generated between the contacts is transferred to the arc running conductor to extend the arc and increase the arc resistance (the arc voltage increases as the arc resistance increases). The overcurrent is limited by taking in a certain arc-extinguishing plate (see Patent Document 1).
In the conventional invention disclosed in Patent Document 1, an arc generated between contacts is caused to travel along an arc running conductor so that the arc is extended at a high speed to improve the current limiting performance. Is provided.

JP 2004-273235 A

In the conventional circuit breaker disclosed in Patent Document 1, there is a drawback that it is impossible to maintain a continuous arc in the arc extinguishing plate. This is caused by the pressure gradient around the arc extinguishing plate, This is because the electromagnetic force from the current path is affected. The pressure gradient around the arc extinguishing plate means that when the arc is taken into the arc extinguishing plate, the arc is pressed in the direction of the external exhaust port, the pressure around the external exhaust port rises, and a wide space between the contacts The arc is pushed back. This phenomenon is greatly affected by the fact that a metal droplet from a melted arc extinguishing plate, a conductor or the like, or a peeled insulator is clogged in the exhaust port, and the flow resistance to the outside increases.
When the point at which an arc occurs in each arc-extinguishing plate is different from the electromagnetic force from the current path of the arc-extinguishing plate, the magnetic driving force from the current path of the arc-extinguishing plate also acts on the arc. As in the case of, a force to push back in the direction between the contacts is generated.
When the arc is discharged from the arc extinguishing plate by the above two actions, the generation of the electrode drop voltage, the effect of cooling the arc, etc. do not work, the arc voltage is lowered and the current limiting performance is lowered.
In addition, in patent document 1, the exhaust port side edge part of an arc running conductor is bent in the arc-extinguishing plate direction, and it has the structure where the electric field is strengthened by shortening the gap of an arc extinguishing plate and a running electrical circuit. . However, the flow resistance between the arc extinguishing plate and the arc running conductor is increased, and as a result, the driving force due to the gas flow in the direction of the external exhaust port required for the arc to travel at high speed to the arc extinguishing plate. It is a factor that decreases

The circuit device according to the present invention includes a fixed contact, a movable contact that contacts and separates from the fixed contact, and a plurality of arc extinguishing that divides and extinguishes an arc generated between the fixed contact and the movable contact when the movable contact is opened. An arc extinguishing device in which plates are arranged, an arc running conductor on the fixed contact side that guides the arc to the arc extinguishing device, an arc running conductor on the movable contact side , and a heat caused by the occurrence of an arc arranged on the back side of the arc extinguishing device An exhaust port for discharging gas to the outside is provided, and the arc traveling conductor and the arc extinguishing plates arranged on the outermost side are opposed to each other with a predetermined gap, and the arc traveling conductor is disposed in the arc extinguishing device. And an electric field enhancing part for enhancing the electric field at a side position on one or both of the opposing surfaces of the outermost arc extinguishing plate and not hindering the flow of the hot gas to the exhaust port. is there.

When the arc reaches the arc-extinguishing plate, the arc on the arc-extinguishing plate is discharged to the contact-side space due to the pressure increase on the external exhaust port side or magnetic driving force, and the arc is dropped on the arc-extinguishing plate. There is a possibility that the current disappears and the phenomenon that the current limiting performance decreases due to the decrease of the arc voltage. According to this invention, the electric field is strengthened by the electric field enhancing portion, and both ends of the arc are continuously held by the arc extinguishing plate, and it becomes possible to suppress the current limiting performance deterioration due to the discharge phenomenon. As a result, current-limiting performance that suppresses overcurrent due to accidents, etc. is improved, and the burden on the structure of the circuit breaker is reduced by reducing the energy injected into the circuit breaker itself. Is possible. Furthermore, it is possible to reduce the load on the line to which the circuit breaker is connected, other circuit breakers connected to the circuit breaker, and the load.
In addition, by providing an electric field strengthening part between the arc extinguishing plate and the arc running conductor opposite to the arc extinguishing plate, it is possible to improve the maintenance performance of the arc extinguishing plate running from between the contacts as compared with the conventional example. By maintaining the arc separation at the arc plate, it is possible to generate an electrode drop voltage, and it is possible to improve the current limiting performance against overcurrent. Furthermore, if the electric field enhancing portion is arranged on the side surface of the arc running conductor, the flow resistance at the center of the arc running conductor, which is the flow path following the exhaust port, is not increased (a projection is provided at the center of the arc running conductor). Therefore, the flow of gas passing over the arc running conductor is stopped, and the driving force of the arc to the arc extinguishing plate is reduced). An additional effect that can prevent deterioration in high-speed running performance can also be expected.
In addition, by enabling good arc maintenance performance in the arc extinguishing plate, it is possible to eliminate re-ignition (occurrence of arc again) at the contact point and the arc running conductor, and to suppress wear of these parts. become. Therefore, the circuit breaker itself has a longer life.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1 FIG.
1 and 2 are views for explaining an arc extinguishing chamber of the circuit breaker according to the first embodiment. More specifically, FIG. 1 is a side view of the arc extinguishing chamber, and FIG. 2 is an arc extinguishing device. Each arc running conductor (the fixed contact side arc running conductor 2 and the movable contact side arc running conductor 7) facing both sides is shown, (a) is a front view thereof, and (b) is a perspective view thereof. Although not shown in these figures, the arc-extinguishing chamber is a container made of an insulator, which detects an abnormal current and outputs a contact opening command, a drive mechanism that transmits the command, etc. It is housed in one piece. 2C and 2D show a modification of the first embodiment and will be described later with paragraph number 0014.

As shown in FIG. 1, the arc extinguishing chamber has a stationary contact side arc traveling conductor 2 having a stationary contact 1, and a movable contact 3 contacting and separating from the stationary contact 1, and the stationary contact side arc traveling conductor 2 and the contactor. An arc extinguishing device 6 comprising a movable contact 4 forming a pair, and a plurality of arc extinguishing plates 5 that take in and divide an arc generated between the fixed contact 1 and the movable contact 3 when the movable contact 4 is separated. Then, the arc on the movable contact 4 commutates, and the movable contact side arc running conductor 7 is guided to the arc extinguishing device 6 and the exhaust port 8 for discharging the hot gas accompanying the arc generation to the outside of the circuit breaker. It is configured.
The fixed contact side arc running conductor 2 to which the fixed contact 1 is fixed extends to the arc extinguishing device 6.
The movable contact 4 is fixedly attached to the movable contact 4, and the tip side (left side in the figure) of the movable contact 3 is an arc horn 101, and the movable contact 4 is composed of a movable contact side arc running conductor 7 and a conductor. Connected and electrically connected. The fixed contact 1 or the movable contact 3 may be substituted by a conductive member constituting the fixed contact side arc running conductor 2 or the movable contact 4.

The fixed contact side arc running conductor 2 and the movable contact side arc running conductor 7 to which the fixed contact 1 is fixed extend to the arc extinguishing device 6 and are sandwiched from both sides (left and right direction in the figure) of the arc extinguishing device 6. It has become.
Further, the fixed contact side arc traveling conductor 2 and the movable contact side arc traveling conductor 7 facing both sides of the arc extinguishing device 6 are provided so as to sandwich the arc on both side surfaces thereof, and the electric field strengthening portion that locally reinforces the electric field. That is, protrusions 102 and 103 having a convex shape are provided. The protrusions 102 and 103 may be provided only on one of the fixed contact side arc traveling conductor 2 or the movable contact side arc traveling conductor 7.
The exhaust port 8 is made of an insulating member and is disposed on the back side of the arc extinguishing device 6.

In the arc extinguishing chamber, when an overcurrent flows through the circuit breaker, an opening / closing mechanism (not shown) of the movable contact 4 is operated, the movable contact 4 is opened, and the fixed contact 1 and the movable contact 3 Arc between (
a1) occurs.
The arc (a1) between the contact points 1 and 3 is first caused by the flow of hot gas in the direction of the exhaust port due to the pressure gradient around the arc generated on the fixed contact side, and the electromagnetic force from the overcurrent flowing in the conductor. It acts and travels in the direction of the arc extinguishing device 6 along the stationary contact side traveling electric circuit continuously extending from the stationary contact 1. Subsequently, the arc spot that reaches the tip of the arc horn 101 is commutated (a2) to the movable contact side arc traveling conductor 7. The movable contact side arc traveling conductor 7 protrudes toward the fixed contact side arc traveling conductor 2 so that the commutation operation proceeds at a high speed. The arc reaches the arc extinguishing device 6 in a substantially vertical state by the speeding up of the commutation and is divided (a3) by the arc extinguishing plate 5. As a result, an electrode effect voltage is generated, the arc voltage is increased, and the current limiting performance is improved.

When the arc is drawn into the arc extinguishing device 6, the pressure gradient around the arc extinguishing plate 5, the electromagnetic force from the current path of the arc extinguishing plate 5, etc. affect, and the force to push back in the direction between the traveling contacts acts. . The pressure gradient around the arc-extinguishing plate 5 means that when the arc is taken into the arc-extinguishing plate 5, the arc is pressed toward the exhaust port 8 and the pressure around the exhaust port 8 is wide in the direction between the contacts. It is higher than the pressure in the space.
The effect of this phenomenon is increased by the fact that molten metal arcs from the arc-extinguishing plate 5 and conductors, separated insulators, etc. are clogged in the exhaust port 8 and the flow path resistance to the outside increases. The electromagnetic force from the current path of the arc-extinguishing plate 5 is different from the electromagnetic force from the current path of the arc-extinguishing plate 5 when the point where the arc is generated on the front and back of each arc-extinguishing plate is different from the current path of the arc-extinguishing plate 5 perpendicular to the arc. The force also acts on the arc, and in some cases, a force to push back in the direction between the contacts is generated as in the case of the pressure increase.
When the arc is discharged from the arc extinguishing device 6 by the above two actions, the electrode drop voltage is not generated, the arc voltage is lowered, and the current limiting performance is lowered.

On the other hand, the fixed contact side and movable contact side arc running conductors 2 and 7 in the first embodiment shown in FIGS. It is possible to prevent the return of the arc by locally strengthening and making it easy to generate an arc spot. Further, the protrusions 102 and 103 are arranged on the side surface of the conductor so as not to disturb the flow of hot gas in the direction of the exhaust port 8 at both ends of the arc extinguishing device 6. To achieve high-speed driving.
As a result, the arc can be stably maintained by the arc-extinguishing device 6, and a good current limiting performance can be realized by generating a high arc voltage.

Next, a modification of the first embodiment will be described.
2 (c) and 2 (d) show arc running conductors 2 and 7 which are modifications of the first embodiment, (c) is a front view thereof, and (d) is a perspective view thereof.
In order to maintain the arc-separated state on the arc extinguishing plate, it is necessary to keep both ends of the arc at the arc running conductor facing the arc extinguishing plate, and strengthening the electric field is effective for arc holding. The electric field can be strengthened by adding irregularities (both or alone) to the surface shape of the arc running conductor.
For this reason, as the electric field enhancing portion, in addition to the protruding portions 102 and 103 having the convex shape, for example, a concave portion formed by a through hole by punching or a concave portion formed by a notch can be considered. The concave portions 2 (c) and (d) are formed by the punching hole 100. The punched hole 100 is formed by punching a part of the fixed contact side arc running conductor 2 and the movable contact side arc running conductor 7 facing the arc extinguishing plate 5 to enhance the electric field at the hole edge portion. An effect similar to that of the protrusions 102 and 103 is realized. Although this modification can be implemented in the same manner in the second embodiment, the description thereof is omitted.

  In this way, if the electric field enhancing portion is configured by arranging convex portions on the side surfaces of the arc running conductors 2 and 7 or by arranging concave portions, the flow path in the central portion of the arc running conductor which is a flow path following the exhaust port. Without increasing the resistance (If a projection is provided at the center of the arc running conductors 2 and 7, the flow of gas passing over the arc running conductor is stopped, and the driving force of the arc to the arc extinguishing plate 5 is reduced. It is possible to make a structure that does not hinder the exhaust of hot gas to the outside, and this can also be expected to prevent the deterioration of the arc high-speed running performance.

In the arc-extinguishing chamber according to the first embodiment, the movable contact side arc traveling conductor 7 protrudes from the fixed contact side arc traveling conductor 2. However, the present invention is not limited to this. The traveling conductor 2 may protrude from the movable contact side arc traveling conductor 7.
That is, the arc traveling type arc extinguishing chamber has two cases as follows, and the present invention can be applied to any of the two known arc extinguishing chambers.
Case (1) In the form described in FIG. 1, the fixed contact side arc travels on the continuous arc traveling conductor and reaches the arc extinguishing device, and the movable contact side arc is moved from the tip of the movable element to the movable contact side arc traveling conductor. 7 commutes to the arc extinguishing device.
Case (2) In this case 2, the fixed contact 1 is arranged on the case (1), that is, the movable contact side arc running conductor 7 in FIG. 1, and this becomes the fixed side arc running conductor (corresponding to 7 in FIG. 1). . In other words, there is no fixed contact on the fixed contact side arc running conductor 2 in FIG. 1, and this fixed contact side arc running conductor 2 becomes a movable contact side arc running conductor (corresponding to 2 in FIG. 1). Accordingly, the rotational direction of the movable contact 4 is opposite to that in FIG. 1, the movable contact 3 of the movable contact 4 opens and closes with respect to the upper fixed contact, and the arc at the tip of the movable contact is the opposite movable side arc. It commutates to the running conductor (corresponding to 2 in FIG. 1) and reaches the arc extinguishing device.

Embodiment 2. FIG.
3 is a view for explaining an arc extinguishing chamber of the circuit breaker according to the second embodiment. More specifically, FIG. 3 is a side view of the arc extinguishing chamber, and FIG. 4 is a front view of the arc extinguishing plate. It is. Although not shown in these figures, the arc-extinguishing chamber is a container made of an insulator, which detects an abnormal current and outputs a contact opening command, a drive mechanism that transmits the command, etc. It is housed in one piece.

As shown in FIG. 3, the arc extinguishing chamber has a stationary contact side arc traveling conductor 2 having a stationary contact 1, and a movable contact 3 contacting and separating from the stationary contact 1, and the stationary contact side arc traveling conductor 2 and the contactor. An arc extinguishing device 6 comprising a movable contact 4 forming a pair, and a plurality of arc extinguishing plates 5 that take in and divide an arc generated between the fixed contact 1 and the movable contact 3 when the movable contact 4 is separated. And a movable contact side arc running conductor 7 in which the arc on the movable contact 4 commutates and guides to the arc extinguishing device, and an exhaust port 8 for discharging the hot gas accompanying the arc generation to the outside of the circuit breaker. Has been.
The fixed contact side arc running conductor 2 to which the fixed contact 1 is fixed extends to the arc extinguishing device 6. A movable contact 3 is fixed to the movable contact 4, an arc horn 101 is provided on the tip side (left side in the figure) from the movable contact 3, and the movable contact 4 is composed of an arc running conductor 7 and a conductor. Connected and electrically connected. The fixed contact 1 or the movable contact 3 may be substituted by a conductive member constituting the fixed contact side arc running conductor 2 or the movable contact 4.

The fixed contact side arc running conductor 2 and the movable contact side arc running conductor 7 to which the fixed contact 1 is fixed extend to the arc extinguishing device 6 and are sandwiched from both sides (left and right direction in the figure) of the arc extinguishing device 6. It has become. Further, the arc extinguishing plate 5 facing the fixed contact side arc traveling conductor 2 and the movable contact side arc traveling conductor 7 is provided with protrusions 104a and 104b as shown in FIG. The protrusions 104 a and 104 b may be provided only on one of the fixed contact side arc traveling conductor 2 or the movable contact side arc traveling conductor 7.
The exhaust port 8 is made of an insulating member and is disposed on the back side of the arc extinguishing device 6.

In the arc extinguishing chamber, when an overcurrent flows through the circuit breaker, an opening / closing mechanism (not shown) of the movable contact 4 is operated, the movable contact 4 is opened, and the fixed contact 1 and the movable contact 3 Arc between (
a1) occurs.
The arc (a1) between the contact points 1 and 3 is first caused by the flow of hot gas in the direction of the exhaust port due to the pressure gradient around the arc generated on the fixed contact side, and the electromagnetic force from the overcurrent flowing in the conductor. It acts and travels in the direction of the arc extinguishing device 6 along the stationary contact side traveling electric circuit continuously extending from the stationary contact 1. Subsequently, the arc spot that has reached the tip of the arc horn 101 is commutated (a2) to the arc traveling conductor 7 on the movable contact side. The movable contact side arc traveling conductor 7 protrudes toward the fixed contact side arc traveling conductor 2 so that the commutation operation proceeds at a high speed. The arc reaches the arc extinguishing device 6 in a substantially vertical state by the speeding up of the commutation and is divided (a3) by the arc extinguishing plate 5. As a result, an electrode drop voltage is generated, the arc voltage is increased, and the current limiting performance is improved.

When the arc is drawn into the arc extinguishing device 6, the pressure gradient around the arc extinguishing plate 5, the electromagnetic force from the current path of the arc extinguishing plate 5, etc. influences, and a force to push back in the direction between the traveling contacts acts. The pressure gradient around the arc-extinguishing plate 5 means that when the arc is taken into the arc-extinguishing plate 5, the arc is pressed toward the exhaust port 8, and the pressure around the exhaust port 8 increases, resulting in a wide inter-contact direction. The arc is pushed back into the space.
The effect of this phenomenon is increased by the fact that molten metal arcs from the arc-extinguishing plate 5 and conductors, separated insulators, etc. are clogged in the exhaust port 8 and the flow path resistance to the outside increases. The electromagnetic force from the current path of the arc-extinguishing plate 5 is different from the electromagnetic force from the current path of the arc-extinguishing plate 5 when the point where the arc is generated on the front and back of each arc-extinguishing plate is different from the current path of the arc-extinguishing plate 5 perpendicular to the arc. The force also acts on the arc, and in some cases, a force to push back in the direction between the contacts is generated as in the case of the pressure increase.
When the arc is discharged from the arc extinguishing device 6 by the above two actions, the electrode drop voltage is not generated, the arc voltage is lowered, and the current limiting performance is lowered.

On the other hand, the arc extinguishing plate 5 according to the second embodiment shown in FIG. 4 locally enhances the electric field at both ends of the arc extinguishing device 6 by providing protrusions 104a and 104b on both sides of the arc extinguishing plate. It becomes possible to prevent the return of the arc by being easily generated. Further, the protrusions 104a and 104b are arranged on the side surfaces of the arc extinguishing plate 5 so that the flow of hot gas in the direction of the exhaust port 8 at both ends of the arc extinguishing device 6 is not disturbed. High-speed traveling to the arc device 6 is realized.
As a result, the arc can be stably maintained by the arc-extinguishing device 6, and a good current limiting performance can be realized by generating a high arc voltage.

In the arc-extinguishing chamber according to the second embodiment, the movable contact side arc traveling conductor 7 is projected from the fixed contact side arc traveling conductor 2. However, the present invention is not limited to this. The traveling conductor may protrude from the movable contact side arc traveling conductor side (see paragraph 16).
Further, the notch portion 5a of the arc extinguishing plate 5 strengthens the deviation of the magnetic flux when the arc is attracted by the arc extinguishing plate due to the deviation of the magnetic flux caused by the arc extinguishing plate. The arc extinguishing apparatus is configured by superimposing a plurality of arc extinguishing plates 5, but there is a model in which a part of the plural sheets does not include a notch.

Embodiment 3 FIG.
FIG. 5 is a front view of the fixed contact side and movable contact side arc running conductors 2 and 7 according to the third embodiment which are arranged to face both sides of the arc extinguishing device.
The protrusions 105a and 105b shown in FIG. 5 are made of a member different from the arc running conductors 2 and 7, and are separated from the arc running conductors 2 and 7 by a separation distance g (movable contact side arc running conductor 7 and fixed contact). The gap arc) between the side arc running conductor side 2 and the outermost arc extinguishing plate 5 is held and arranged in a casing constituting an arc extinguishing chamber space made of an insulating member not shown in the drawing, that is, an arc It is arranged outside the flow path. By arranging in this way, the electric field at both ends of the arc extinguishing device 6 is locally strengthened, and an arc generated from an arc spot generated in the arc running conductors 2 and 7 facing the arc extinguishing plate causes the projections 105a and 105b to By making it pass, an earth spot is easily generated around the arc extinguishing plate, and it is possible to prevent the return of the arc.
Further, as described above, the projecting portions 105a and 105b are formed of a member different from the arc running conductors 2 and 7 and are disposed on the side surfaces of the arc running conductors 2 and 7, so The arrangement is such that the flow of hot gas in eight directions is not hindered, and high-speed travel from the point of contact to the arc extinguishing device 6 is realized. As a result, the arc can be stably maintained by the arc-extinguishing device 6, and a good current limiting performance can be realized by generating a high arc voltage. Further, it is possible to prevent fusing due to wear of the arc running conductor which is a current path, and to prevent the arc from reaching the arc extinguishing plate.
The projecting portions 105a and 105b, the movable contact side arc traveling conductor 7 and the fixed contact side arc traveling conductor 2 do not need to be electrically connected.

Embodiment 4 FIG.
FIG. 6 is a front view of the stationary contact side and movable contact side arc running conductors 2 and 7 according to the fourth embodiment arranged opposite to both sides of the arc extinguishing device.
The protrusions 102 and 103 shown in FIG. 6 are disposed on both sides of the arcing conductors 2 and 7 on the fixed contact side and the movable contact side, and are covered with an insulating resin 106. As a result, the electric field at both ends of the arc extinguishing device 6 is locally strengthened, and an arc spot is easily generated, thereby preventing the return of the arc and preventing the protrusions 102 and 103 from being consumed. It is possible to generate insulating steam from 106, perform arc cooling, increase the pressure inside the arc extinguishing chamber, etc., and further improve the current limiting performance. Further, the protrusions 102 and 103 are arranged on the side surfaces of the arc running conductors 2 and 7 so that the hot gas flow in the direction of the exhaust port 8 at both ends of the arc extinguishing device 6 is not hindered. High-speed traveling to the arc device 6 is realized.
As a result, the arc can be stably maintained by the arc-extinguishing device 6, and a good current limiting performance can be realized by generating a high arc voltage.
Note that the protruding portions 102 and 103 in the fourth embodiment are covered with an insulating resin regardless of whether or not the arc running conductors 2 and 7 are electrically connected.

It is a side view which shows the arc-extinguishing chamber of the circuit breaker in Embodiment 1 of this invention. The arc running conductors 2 and 7 facing both sides of the arc extinguishing device are shown, (a) is a front view thereof, and (b) is a perspective view thereof. (C), (d) shows each arc running conductor 2, 7 which is a modification of Embodiment 1, (c) is the front view, (d) is the perspective view. It is a side view which shows the arc-extinguishing chamber of the circuit breaker in Embodiment 2. It is a front view of the arc-extinguishing board of the circuit breaker in Embodiment 2. FIG. 10 is a front view of each arc running conductor 2 and 7 in the third embodiment. FIG. 10 is a front view of each arc running conductor 2 and 7 in the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed contact 2 Fixed contact side arc running conductor 3 Movable contact 4 Movable contact 5 Arc extinguishing plate 5a Notch part of arc extinguishing plate 5 Arc extinguishing device 7 Moving contact side arc running conductor 8 Exhaust port 101 Arc horn 100 Stamping hole (Concave)
102, 103 Protruding part (convex part)
104a, 104b Protruding part (convex part)
105a, 10b Protruding part (convex part)
106a, 106b Insulating resin.

Claims (4)

An arc extinguishing device in which a plurality of arc extinguishing plates are arranged to divide and extinguish an arc generated between the fixed contact and the movable contact when the movable contact is opened; an exhaust port for discharging the fixed contact side of the arc running conductor and the movable contact side of the arc running conductors to induce the arc to the arc extinguishing device, the hot gas with disposed on the back side of the arc extinguishing device to arcing outside With
The arc running conductor and the arc extinguishing plates arranged on the outermost side are opposed to each other with a predetermined gap, and in the arc extinguishing apparatus, the arc running conductor and the opposed surfaces of the outermost arc extinguishing plate A circuit breaker characterized in that an electric field enhancing part for enhancing an electric field is provided at any one or both of the side faces and at a side face position that does not obstruct the flow of the hot gas to the exhaust port .   2. The circuit according to claim 1, wherein the electric field enhancing portion is constituted by one or both of a protruding protrusion and a through hole or a recess formed by a notch. Circuit breaker. 3. The circuit breaker according to claim 2 , wherein the convex portion has a surface on the arc running conductor side covered with an insulating resin. 3. The circuit breaker according to claim 2 , wherein the convex portion is disposed outside the gap and is made of a member different from the arc running conductor.

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