JP2013164920A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker having an arc runner capable of improving cutoff performance by hastening the travel of an arc on the arc runner.SOLUTION: A circuit breaker includes: a stationary terminal 1 having a stationary contact 1a; a movable terminal 2 having a movable contact 2a that comes into and out of contact with the stationary contact 1a; an arc-extinguishing device 4 extinguishing an arc 5 occurring between the stationary contact 1a and the movable contact 2a; and an arc runner 16 guiding the arc 5 occurring between the stationary contact 1a and the movable contact 2a to the arc-extinguishing device 4 side. At a position of the arc runner 16 facing the arc-extinguishing device 4, an arc running portion 16a projecting toward the arc-extinguishing device 4 and extending in a direction longitudinally of the arc runner 16 is formed.

Description

  The present invention relates to a circuit breaker such as a circuit breaker or a leakage breaker, and more particularly to a circuit breaker including an arc runner that guides an arc generated between contacts to an arc extinguishing device.

As this type of circuit breaker, a circuit breaker disclosed in Patent Document 1 is known.
FIG. 8 is a perspective view of a current breaker of a circuit breaker showing a conventional example, and FIG. 9 is a view showing an arc 5 with the arc extinguishing device 4 removed from FIG.

In the figure, the current interrupting portion of the circuit breaker is composed of a fixed contact 1, a movable contact 2, and an arc extinguishing device 4, and is housed in a main body case comprising a case and a cover (not shown).
The fixed contact 1 is bent at one end in a U shape, has a fixed contact 1a at the tip, and is provided with a terminal 1d on the power source side at the other end.

  The movable contact 2 has a movable contact 2a that comes into contact with the fixed contact 1a at one end, and is rotatably arranged around a support shaft 2b at the other end. It is opened and closed to the open position. The other end of the movable contact 2 is connected to a load-side terminal (not shown) via a lead wire (not shown).

  The arc extinguishing device 4 includes a plurality of magnetic plates 3 having V-shaped cutouts arranged in an upper and lower stage through a gap, and a support member (not shown) that supports the magnetic plates 3 from both sides, and is movable. It arrange | positions ahead of the opening movement path | route of the contactor 2. FIG.

  Further, a flat arc runner 6 for moving the arc 5 generated between the fixed contact 1a and the movable contact 2a to the arc extinguishing device 4 side is attached to the U-shaped tip of the fixed contact 1.

Further, an arc driving body 7 is disposed in the vicinity of the arc runner 6 as means for increasing the arc driving force.
The arc driving body 7 is made of a U-shaped magnetic body having a pair of left and right leg portions 7 a and 7 a and a connecting portion 7 b that connects between the leg portions 7 a and 7 a, and the leg portions 7 a and 7 a are positioned on both sides of the arc runner 6. Moreover, it is combined with the arc runner 6 through a gap from the back side. The arc driver 7 is fixedly supported by the base 1e of the fixed contact 1 via an insulating base (not shown). Reference numeral 8 denotes an insulator provided inside the arc driving body 7.

  In the circuit breaker configured as described above, when the circuit breaker is on, the movable contact 2 is closed, and the movable contact 2a of the movable contact 2 and the fixed contact 1a of the fixed contact 1 are in contact. . The current flows from the terminal 1d on the power supply side to the load side terminal (not shown) via the fixed contact 1, the fixed contact 1a, the movable contact 2a, and the movable contact 2.

  In such a circuit breaker, when a large current such as a short circuit current flows, the movable contact 2 opens from the fixed contact 1 due to the electromagnetic repulsion, and an arc 5 is formed between the fixed contact 1a and the movable contact 2a. Occur. The arc 5 moves to the arc runner 6 side by an electromagnetic force based on a current flowing through the stationary contact 1. Thereby, the arc on the fixed contact 1a is switched to the arc runner 6, and the consumption of the fixed contact is alleviated.

  Here, an arc driving body 7 is provided in the vicinity of the arc runner 6, and the magnetic field of the current flowing through the fixed contact 1 is concentrated on the arc driving body 7 made of a magnetic material, and the fixed contact of the arc 5 is caused by this concentrated magnetic field. The leg on the 1a side can be driven toward the tip end side of the arc runner 6.

  The arc 5 moved to the tip end side of the arcrunner 6 is drawn into the inside by the action of the magnetic plate 3 and is divided and cooled. As a result, the voltage between the fixed contact and the movable contact is increased at a stretch, and the current is rapidly limited to be interrupted.

  Patent Document 2 discloses that one fixed contact, the other fixed contact, an arc runner provided at the tip of one and the other fixed contact, and a movable contact that bridges the one and the other fixed contacts. A two-point circuit breaker including a child, an arc extinguishing device arranged before and after the movable contact, and an arc commutation plate arranged to straddle each arc extinguishing device is disclosed.

JP 2005-216807 A Japanese Patent No. 2965025

  By the way, the conventional circuit breaker is provided with an arc runner at the tip of the stationary contact in order to guide the arc generated between the contacts to the arc extinguishing device side. However, in the region where the energization current is small (for example, 100 A or less), the electromagnetic force acting on the arc is small because it is proportional to the square of the current, the arc movement on the arc runner is slow, and the interruption time is long. In addition, there is a problem that the interruption performance particularly in a small current region is deteriorated.

  Also, when trying to apply a circuit breaker equipped with a conventional arc runner as a DC breaker that cuts off DC current, the DC current differs from AC current because there is no current zero point. There is a problem that it is difficult to cut off and it is difficult to apply a circuit breaker equipped with a conventional arc runner as it is as a DC breaker.

  Then, the subject of this invention is providing the circuit breaker provided with the arc runner which can improve interruption | blocking performance by accelerating the movement of the arc on an arc runner.

  In order to achieve the above object, according to the present invention, a fixed contact having a fixed contact, a movable contact having a movable contact contacting and separating from the fixed contact, and an arc generated between the fixed contact and the movable contact are provided. A circuit breaker comprising an arc extinguishing device for arc extinguishing and an arc runner for guiding an arc generated between a fixed contact and a movable contact to the arc extinguishing device side, wherein the arc extinguishing device is disposed at a position facing the arc extinguishing device. An arc running part that protrudes toward the apparatus and extends in the longitudinal direction of the arc runner is formed, or an arc running part that includes a groove extending in the longitudinal direction of the arc runner is formed at a position facing the arc extinguishing device of the arc runner. To do.

In the above circuit breaker, the arc traveling part is preferably formed by a triangular projection provided on the arc runner.
The arc runner may be formed at a position facing an arc extinguishing device of an arc commutation plate that commutates an arc generated between the fixed contact and the movable contact. Furthermore, you may make it form the said arc runner in the position facing the arc-extinguishing apparatus of the said fixed contact.

  According to the present invention, since the movement of the arc on the arc runner is accelerated, the interruption time is shortened and the interruption performance is improved.

The principal part side view of the electric current interruption part of the circuit breaker which shows the 1st Embodiment of this invention 1 is a perspective view of the main part of the current interrupting unit shown in FIG. 2A is a cross-sectional view of the arc runner taken along the line AA in FIG. 2, and FIG. (A) is sectional drawing of the conventional arc runner, (b) is a figure showing the traveling route of the arc which moves on an arc runner. The figure which compared the arc running time in the arc runner of the present invention and the conventional example Sectional view showing other shapes of arcrunner The principal part side view of the electric current interruption part of the circuit breaker which shows the 2nd Embodiment of this invention The perspective view of the current interruption part of the circuit breaker which shows a prior art example The figure which removed the arc extinguishing apparatus from FIG. 8, and showed the arc

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a side view of a main part of a current interrupting part of a two-point circuit breaker showing a first embodiment of the present invention, FIG. 2 is a perspective view of a main part of the current interrupting part shown in FIG. (A) is the AA arrow sectional drawing of the arc runner of FIG. 2, (b) is a top view of the arc runner shown in FIG. 1, It is the figure showing the traveling route of the arc which moves on an arc runner.

  In FIG. 1, the current interrupting part of the circuit breaker has one fixed contact 1 having a fixed contact 1a, a movable contact 2a that contacts the fixed contact 1a at one end, and a movable contact (not shown) at the other end. The movable contact 2 has a V-shaped notch arranged in the upper and lower stages through a gap, and supports a plurality of magnetic plates 3 arranged in front of the moving path of the movable contact 2a and the magnetic plate 3. An arc extinguishing device 4 having a support member (not shown) and an arc commutation plate which is disposed on the side of the movable contact 2 opposite to the movable contact 2a and commutates the arc 5 on the movable contact 2 generated between the contacts. 10.

  The movable contact 2 is configured to be opened and closed in the vertical direction with respect to the fixed contact 1 by an opening / closing mechanism (not shown). The current interrupting unit is housed in a main body case including a case and a cover (not shown).

  In FIG. 1, the other fixed contact and the other arc extinguishing device are omitted because they have the same configuration as the one fixed contact 1 and the one arc extinguishing device 4. One fixed contact 1 is connected to a terminal on the power supply side, and the other fixed contact (not shown) is connected to a terminal on the load side.

  Here, in this embodiment, an arc runner 16 is provided at one end of the arc commutation plate 10 to guide the arc 5 generated between the contacts to the arc extinguishing device 4 side. The arc runner 16 can be formed from copper or iron. The arc runner 16 and the arc commutation plate 10 may be formed separately, but the arc runner 16 may be formed integrally with the arc commutation plate 10.

In addition, as shown in FIG. 2, the arc runner 16 is formed with an arc running portion 16 a that protrudes toward the arc extinguishing device 4 at a position facing the arc extinguishing device 4 of the arc runner 16.
The arc traveling portion 16a is formed at the center in the width direction of the arc runner 16 so as to extend along the longitudinal direction of the arc runner 16. In this embodiment, as shown in FIG. It is formed as a protrusion having a shape. Moreover, the upper surface of the arc runner 16 on both sides of the protrusion is an inclined surface.

The arc runner 16 having the arc traveling portion 16a is also provided at the other end of the arc commutation plate 10 (not shown).
An arc runner 1b is formed closer to the arc extinguishing device 4 than the fixed contact 1a of the fixed contact 1, and protrudes toward the arc extinguishing device 4 at a position facing the arc extinguishing device 4 of the arc runner 1b. An arc traveling portion 1c is formed. This arc travel part 1c is formed to extend along the longitudinal direction of the arc runner 1b at the center in the width direction of the arc runner 1b, similarly to the arc travel part 16a formed on the arc runner 16. The cross section is formed as a protrusion having a triangular shape. The arc runner 1b can be formed of copper or iron. The arc runner 1b and the stationary contact 1 may be formed separately, but the arc runner 1b may be integrally formed with the fixed contact 1.

The arc runner 1b having the arc traveling portion 1c is also provided on the other fixed contact (not shown).
Furthermore, in order to improve the electromagnetic force acting on the arc, the arc driving body 7 made of a U-shaped magnetic body may be arranged so as to surround the arc runner 16 from the lower side.

Next, the operation of the present invention will be described.
In the ON state of the circuit breaker, the movable contact 2 is closed, and the movable contact 2 a of the movable contact 2 and the fixed contact 1 a of the fixed contact 1 are in contact. In addition, the current flows from the terminal on the power supply side to one terminal on the load side (not shown) via one fixed contact 1, the movable contact 2, and the other fixed contact (not shown).

  In such a circuit breaker, when a large current such as a short circuit current flows, the movable contact 2 is separated from the fixed contact 1 as indicated by the arrow in FIG. 1 due to the electromagnetic repulsion, and the fixed contact 1a and the movable contact 2a An arc 5 is generated between the two. The arc 5 is driven to the arc extinguishing device 4 side by an electromagnetic force generated by a current flowing through the fixed contact 1 or the arc itself.

  At that time, the leg of the arc 5 on the fixed contact 1a side moves from the fixed contact 1a to the arc runner 1b, and the arc leg on the movable contact 2a side moves from the movable contact 2a to the tip of the movable contact 2 and the arc commutation plate 10. It moves to the arc runner 16 via. As a result, the arcs on the fixed contact 1a and the movable contact 2a are switched to the arc runners 1b and 16, and the contact wear is alleviated.

  The leg of the arc 5 on the fixed contact 1a side that has moved to the arc runner 1b travels on the arc runner 1b toward the arc extinguishing device 4 side, and the leg of the arc 5 on the movable contact 2a side that has moved to the arc runner 16 It runs on the arc extinguishing device 4 side.

  Here, the arc driving body 7 is disposed so as to surround the arc runner 16, and the driving force of the arc 5 can be increased by collecting the magnetic flux of the current flowing through the arc runner 16 in the arc driving body 7.

Then, the arc 5 driven to the arc extinguishing device 4 side is drawn into the inside by the action of the magnetic plate 3, is divided and cooled and disappears, and the current is interrupted.
Here, the traveling path of the arc on the arc runner of the present invention and the conventional example will be described with reference to FIGS.

  FIG. 3A is a sectional view of an arc runner having a triangular shape according to the present invention, and FIG. 3B is a view showing a travel path of an arc on the arc runner. FIG. 4A is a cross-sectional view of a conventional arc runner having a flat plate shape, and FIG. 4B is a diagram showing a travel path of an arc on the arc runner.

In the figure, reference numeral 5 denotes an arc, and 5a and 5b denote travel paths of the arc 5.
Since the conventional arc runner 6 shown in FIG. 4 is formed in a flat plate shape, the arc 5 on the arc runner 6 is the current flowing through the arc runner, the current of the arc itself, the turbulence (flow) of the arc gas, and the arc runner in the vicinity of the arc. Due to the influence of temperature or the like, as shown in FIG. 4 (b), a complicated traveling route 5b is taken toward the arc extinguishing device direction (left side of FIG. 4 (b)) while meandering.

Therefore, in the arc runner 6 having a conventional flat plate shape, the arc 5 also moves in the direction perpendicular to the arc extinguishing device direction, and the arc moving path is long.
In particular, at a small current (for example, 100 A or less) with a small interruption current, the generation of arc gas is small, and the electromagnetic force in the direction of the arc extinguishing device due to the current flowing through the arc runner is also weak, which has been a cause of slow arc movement.

  On the other hand, the arc runner 16 of the present invention shown in FIG. 3 forms an arc running portion 16a composed of a protrusion having an inclined surface on the upper surface of the arc runner. For this reason, the arc 5 commutated on the arc runner 16 is mainly ignited by the arc traveling portion 16a on the arc runner 16 having the smallest distance from the fixed contact 1 due to the property of igniting in the shortest path. It will be.

  Thereby, in the arc runner 16 of the present invention, the arc 5 on the arc runner does not move in the direction perpendicular to the arc extinguishing device direction (left side of FIG. 3B), as shown in FIG. In addition, since the vehicle travels along the travel path 5a that goes straight toward the arc extinguishing device 4 on the arc traveling unit 16a, the arc 5 moves faster in the arc extinguishing device direction.

  In addition, the arc traveling unit 1c provided in the arc runner 1b also travels straight on the arc traveling unit 1c toward the arc-extinguishing device 4 as in the arc traveling unit 16a provided in the arc runner 16. 5 moves in the direction of the arc extinguishing device quickly.

Here, the result of experimentally determining the influence of the cross-sectional shape of the arc runner on the running of the arc is shown in FIG.
FIG. 5 is a diagram comparing arc travel times in the arc runner of the present invention and the conventional example.

  In the experiment, when the current of 12.5 A was cut off, the travel time required for the arc to travel a fixed distance (about 5 cm) on the arc runner arranged in parallel was calculated. Shape) and a triangular shape (the shape of the present invention). In the figure, the arc running time (average value) in the arc runner of the conventional example (flat plate shape) is set to 1, and is represented by a ratio.

As a result, as shown in FIG. 5, it can be seen that the travel time of the arc of the present invention (triangular shape) is about ½ faster than the travel time of the arc of the conventional example (flat plate shape). .
Thus, in the circuit breaker including the arc runner of the present embodiment, the arc on the arc runner moves to the arc extinguishing device side quickly, so that the interruption time can be shortened and the interruption performance is improved. Moreover, since the arc firing time on the arc runner is shortened, the arc runner itself can be prevented from being consumed, and high durability can be achieved.

  The arc runner having the arc running part of the present embodiment may be provided only on one of the arc commutation plate 10 or the fixed contact 1, but the arc runner is provided on both the arc commutation plate 10 and the fixed contact 1. If it is provided, the movement of the arc toward the arc extinguishing device can be performed more smoothly.

  The arc traveling portions 16a and 1c may have any shape as long as the arc on the arc runner can travel along the longitudinal direction of the arc runner without moving in the width direction of the arc runner. But you can.

  FIG. 6 is a cross-sectional view showing another shape of the arc runner. The arc traveling portion shown in FIG. 6 (a) has an arc-shaped protrusion 16b formed on the arc runner 16, and the arc moves on the arc-shaped protrusion 16b along the longitudinal direction of the arc runner 16. It is. The arcuate protrusion 16b may have a rectangular shape or a triangular shape.

  Further, the arc traveling portion shown in FIG. 6B is provided with a rectangular groove portion 16c on the arc runner 16, and the arc moves along the longitudinal direction of the arc runner 16 on the corner portion 16d of the groove portion 16c. Is. The shape of the groove 16c may be an arc or a triangle.

  Furthermore, the arc traveling part shown in FIG. 6C is provided with a plurality of triangular protrusions 16e on the arc runner 16, and the arc is any one of the plurality of protrusions 16e. It moves along the longitudinal direction of the arc runner 16 on 16e. The shape of the triangular protrusion 16e may be an arc or a rectangle.

  As described above, according to the arc runner including the arc traveling unit illustrated in FIGS. 6A to 6C, the arc on the arc runner is similar to the arc runner including the arc traveling unit 16 a having a triangular shape illustrated in FIG. 3. Moves straight toward the arc extinguishing device side, so that the traveling time is faster than the conventional flat plate arc runner, and the interruption time can be shortened.

  6A to 6C, the upper surface of the arc runner 16 on both sides of the arc traveling portion is inclined like the arc runner 16 illustrated in FIG. The arc may not be moved.

Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 7: is a principal part side view of the electric current interruption part of the one-point circuit breaker which shows the 2nd Embodiment of this invention.

In the present embodiment, the other end of the movable contact 12 having a movable contact 12a at one end is pivotally supported on a rotating shaft (not shown), and the movable contact is rotated to open the pole.
In the figure, the current breaker of the circuit breaker includes a fixed contact 1 having a fixed contact 1a, a movable contact 12 having a movable contact 12a at one end, and V-shaped notches arranged in an upper and lower stage via a gap. A plurality of magnetic plates 3 and a support member (not shown) that supports the magnetic plates 3, and an arc extinguishing device 4 disposed in front of the moving path of the movable contact 12 a and an arc commutation plate 10. Has been.

  Similarly to the first embodiment, the arc runner 16 formed at one end of the arc commutation plate 10 is provided with an arc running portion 16a, and the arc runner 1b formed at the tip of the fixed contact 1 is provided with an arc running portion 1c. ing.

  The fixed contact 1 is connected to a terminal on the power supply side (not shown), and the other end of the movable contact is connected to the other end of the arc commutation plate via a lead wire (not shown) and connected to the load side terminal. It is connected.

  In the circuit breaker, when a large current such as a short-circuit current flows, the movable contact 12 is separated from the fixed contact 1 as indicated by an arrow in FIG. 7, and an arc 5 is formed between the fixed contact 1 and the movable contact 12a. However, as in the first embodiment, the arc 5 travels on the arc traveling portions 1c and 16a provided in the arc runners 1b and 16 and is extinguished by the arc extinguishing device 4.

  According to the present embodiment, even in the one-point circuit breaker configured to rotate and open the movable contact, similarly to the first embodiment, when the current is interrupted, the arc travels on the arc runner. Time can be shortened and cut-off time can be shortened.

DESCRIPTION OF SYMBOLS 1 Fixed contact 1a Fixed contact 1b Arc lanna 1c Arc travel part 2 Movable contact 2a Movable contact 3 Magnetic plate 4 Arc extinguishing device 5 Arc 10 Arc commutation plate 16 Arc runner 16a Arc travel part 16c Groove part

Claims (5)

A stationary contact having a stationary contact;
A movable contact having a movable contact contacting and separating from the fixed contact;
An arc extinguishing device for extinguishing an arc generated between the fixed contact and the movable contact;
In a circuit breaker comprising an arc runner for guiding an arc generated between a fixed contact and a movable contact to the arc extinguishing device side,
A circuit breaker characterized in that an arc running portion that protrudes toward the arc extinguishing device and extends in the longitudinal direction of the arc runner is formed at a position facing the arc extinguishing device of the arc runner. A stationary contact having a stationary contact;
A movable contact having a movable contact contacting and separating from the fixed contact;
An arc extinguishing device for extinguishing an arc generated between the fixed contact and the movable contact;
In a circuit breaker comprising an arc runner for guiding an arc generated between a fixed contact and a movable contact to the arc extinguishing device side,
A circuit breaker characterized by forming an arc running part composed of a groove extending in the longitudinal direction of the arc runner at a position facing the arc extinguishing device of the arc runner.   The circuit breaker according to claim 1, wherein the arc traveling part is a triangular protrusion provided on the arc runner.   An arc commutation plate for commutating an arc generated between a fixed contact and a movable contact is provided, and the arc runner is formed at a position facing an arc extinguishing device of the arc commutation plate. Circuit breaker described in. The circuit breaker according to claim 1 or 2, wherein the arc runner is formed at a position facing the arc-extinguishing device of the stationary contact.