JP2010272326A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker in which it is easy to take in an arc into an arc extinguishing device, a space for the arc extinguishing device is increased, and which is superior in arc enlargement effect to utilize a magnetic attracting force. <P>SOLUTION: The circuit breaker includes a fixed contactor 4 having a first conductor part 4a at which a fixed contact 3 is installed and which is arranged and installed so that a current flows in a direction opposite to a movable contactor 6 when an electrode is closed, and a second conductor part 4b to which one end part side is connected so that the end part side is folded back from the end part of this first conductor part, which is arranged and installed so that the current flows in the same direction as that of the movable contact when the electrode is closed, and in which an external connecting terminal is installed at the other end part side, the first conductor part and the folded connecting part of the second conductor part are formed to have an acute angle when seen from sideward, and the other end part side of the second conductor part is inclined so as to be gradually separated from the first conductor part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a circuit breaker that can be preferably used as a circuit breaker for wiring, an earth leakage breaker, or the like.

  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. When an overcurrent is interrupted during an accident, etc., the electromagnetic force generated between the energized conductors is used to open the movable contact with the movable contact at high speed, thereby extending the arc length and limiting the arc resistance. It is important that the arc generated between the contacts or the arc generated between the contacts is drawn into the arc extinguishing plate and divided, and the arc voltage is increased to limit the current by generating the electrode drop voltage and cooling the arc. 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. .

  As a conventional circuit breaker for wiring, when the direction in which the movable contact in the contact closed state is separated from the fixed contact is upward, the first conductor portion that connects the fixed contact to the terminal portion, the first contact having the fixed contact 2 conductor parts and the 3rd conductor part which connects the 1st conductor part and the 2nd conductor part to the up-and-down direction, and the 3rd conductor part is not provided with the movable contact of the movable contact from the position of the above-mentioned fixed contact The first conductor portion is disposed on the other end side and on the opposite side of the terminal portion, and the first conductor portion is disposed above the contact contact surface when the contact is closed, and from the contact surface of the movable contact when the contact is opened. There is one in which the portion of the first conductor portion that is disposed below and can be seen from the surface of the movable contact when the contact is opened is covered with an insulating material (see, for example, Patent Document 1).

JP-A-6-20547 (first page, FIG. 1)

  In the conventional circuit breaker as described above, all the current paths of the stationary contact immediately after the contact is opened generate an electromagnetic force that extends the arc toward the terminal portion side. As a result, the arc voltage can be rapidly increased, and when the opening distance of the movable contact increases, the arc is taken into the arc extinguishing device and the arc is cooled to generate a high arc voltage. However, since the upper conductor constituting the fixed contact is almost at the same height as the terminal portion, the arc cannot be taken into the arc extinguishing device unless the movable contact is separated to the same distance. Further, the space of the arc extinguishing device itself that divides the arc to increase the arc voltage is small, and the volume of the arc extinguishing plate constituting the arc extinguishing device is inevitably reduced and the number of arc extinguishing plates is reduced. As a result, it becomes difficult to improve wear resistance by expanding the space against the wear of the arc extinguishing device due to the thermal load at the time of arc occurrence, and furthermore, the magnetic attraction force of the arc extinguishing device itself is used near the current zero point. There was a problem that the arc stretching effect would not occur.

  The present invention has been made to solve the above-described problems of the prior art, and it is easy to incorporate an arc into the arc extinguishing device, and the space of the arc extinguishing device itself can be expanded, and the magnetic attractive force can be increased. An object of the present invention is to provide a circuit breaker that has a high effect of extending the arc by using the.

  The circuit breaker according to the present invention includes a first conductor portion provided with a fixed contact so that a current flows in a direction opposite to that of the movable contactor when closed, and one end side of the circuit breaker is an end of the first conductor portion. Fixed contact having a second conductor portion which is connected so as to be folded back from the portion and is arranged so that current flows in the same direction as the movable contact when closed, and an external connection terminal is provided on the other end side It has. The folded connection portion between the first conductor portion and the second conductor portion is formed at an acute angle when viewed from the side, and the other end portion side of the second conductor portion is gradually separated from the first conductor portion. It is made to incline.

  In the present invention, the angle of the folded connection portion of the first conductor portion and the second conductor portion constituting the fixed contact is made acute, and the second conductor portion is inclined with respect to the first conductor portion, that is, non-parallel. By doing so, it is possible to expand the space of the arc extinguishing device disposed above the fixed contact and to arrange the arc extinguishing plate around the contact point contact position. By expanding the space of the arc extinguishing device, it is possible to increase the number of arc extinguishing plates arranged without increasing the volume of the arc extinguishing plate itself or reducing the thickness of one sheet. As a result, an electromagnetic attractive force in the direction of the arc extinguishing device is applied to the arc from the beginning of the opening, the cooling performance is improved by increasing the volume of the arc extinguishing device itself, and the number of arc breaking points is increased by increasing the number of arc extinguishing plates. This improves the shut-off performance.

The side view which shows the principal part structure of the arc-extinguishing chamber part in the closing state of the circuit breaker which concerns on Embodiment 1 of this invention. The side view which shows the principal part structure of the arc-extinguishing chamber part in the open circuit state of the circuit breaker which concerns on Embodiment 1 of this invention. The side view which shows the electricity supply part of the closing state shown by FIG. The side view which shows the electricity supply part of the open state shown by FIG. The top view which shows the stationary contact shown by FIG. 1, FIG. The side view which shows the electricity supply part in the closing state of the circuit breaker which concerns on Embodiment 2 of this invention. The side view which shows the electricity supply part in the open circuit state of the circuit breaker which concerns on Embodiment 2 of this invention. The side view which shows the principal part structure of the arc-extinguishing chamber part in the closing state of the circuit breaker which concerns on Embodiment 3 of this invention. The side view which shows the principal part structure of the arc-extinguishing chamber part in the open circuit state of the circuit breaker which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
Hereinafter, the circuit breaker according to Embodiment 1 of the present invention will be described with reference to FIGS. In the figure, the arc-extinguishing chamber portion of the circuit breaker is configured with a relay unit that detects an abnormal current (not shown) and outputs an opening command, a drive mechanism unit to which the opening command is transmitted, and the like. 1 and FIG. 2, the base 1 made of an insulator constituting the casing and the cover 2 are divided into three phases in parallel and accommodated in the casing. In the arc extinguishing chamber of each phase, a fixed contact 4 to which the fixed contact 3 is fixed and a movable contact 6 to which the movable contact 5 is fixed at one end side are arranged. The other end side of the movable contact 6 is rotatably supported by a rotating shaft 6a as a support portion. A cross bar 7 is provided so as to surround the movable contact 6 in the vicinity of the rotary shaft 6a. The cross bar 7 is linked to a drive mechanism (not shown) so that the movable contact 6 is moved around the rotary shaft 6a. It is configured to open and close.

  The fixed contact 4 has a predetermined dimension extending in a first direction (left direction in the drawing) from the fixed contact 3 provided at a position facing the movable contact 5 toward the other end of the movable contact 6. A first conductor portion 4a formed in a bifurcated shape (substantially T-shaped) so as to be divided in two directions opposite to each other in a direction crossing the first direction, and one end portion side (left side in the figure) Is formed by two parallel pieces, and the tip of each of the first conductor portions 4a is connected to each of the two ends of the first conductor portion 4a so as to be folded at an acute angle when viewed from the side, and the other end from the folded connection portion A. The part side (right side in the figure) is inclined in the direction opposite to the first direction, and is inclined in the opening direction of the movable contact 6 with respect to the first conductor part 4a, that is, in the upward direction in the figure. And a second conductor portion 4b provided with an external connection terminal 8 for connecting to an external conductor at the other end. That.

  Then, the folded connection portion A formed at an acute angle of the fixed contact 4 is inserted so as to extend to the vicinity of the extension portion of the movement locus when the cross bar 7 is closed. Further, when the direction of the cover 2 is upward in the drawing, the substantially lower half of the one end side (left side in the drawing) of the second conductor portion 4b is substantially below the movable contactor 6 in the closed state. The other end side is connected to the external connection terminal 8 so that the energization direction is substantially the same as that of the movable contact 6. The first conductor portion 4 a to which the fixed contact 3 is fixed is disposed below the movable contact 6, has a substantially T-shaped planar shape, and the energization direction is opposite to that of the movable contact 6. The folded connection portion A of the second conductor portion 4b and the first conductor portion 4a is formed so that the left side of the drawing has an acute angle when viewed from the side surface direction (the front side in FIG. 1).

  Further, when the movable contact 6 is in an open state, the second conductor portion 4 b is covered with an insulator 9 in a range that can be seen from the movable contact 5. When the fixed contact 4 is viewed from above, it is formed as shown in FIG. 5. The fixed contact 4 is cut into one flat plate by, for example, a press to raise a portion that becomes the second conductor portion 4b. It can be formed easily. The movable contact 6 is arranged so as to enter a space between two parallel pieces of the second conductor portion 4b connected so as to be folded back into a bifurcated portion at the end portion of the first conductor portion 4a. Then, it opens and closes the fixed contact 3 of the first conductor portion 4a. Above the fixed contact 4, a plurality of arc extinguishing layers are stacked at a predetermined interval to capture and divide an arc generated between the fixed contact 3 and the movable contact 5 when the movable contact 6 is opened. An arc extinguishing device (grid) 11 comprising a plate 10 is arranged.

  Moreover, in order to discharge | emit the hot gas accompanying arc generation | occurrence | production to the exterior of a circuit breaker, the right side of the arc-extinguishing apparatus 11 is the exhaust port 12. FIG. A barrier 13 made of an insulating material is disposed at the exhaust port 12 to prevent foreign matter from entering from the outside. The barrier 13 is generally in a state where the lower side is fixed by the base 1 and the upper side is not restrained. Therefore, since the internal pressure of the arc extinguishing chamber rises when an arc is generated, the upper side of the barrier 13 tilts outward and is opened outward. In addition, the shape of the arc extinguishing plate 10 and the configuration of other parts not shown are the same as, for example, the known prior art.

  Next, the operation of the first embodiment configured as described above will be described. In the ON state of FIG. 1, when an overcurrent such as an accident current flows through the circuit breaker in the contact ON state, the magnetic flux from the conductor constituting the fixed contact 4 is linked to the movable contact 6, Electromagnetic force is generated in the direction in which the contact opens (OFF state), and the driving force acts on the movable contact 6 in the opening direction. That is, since a reverse current flows through the first conductor portion 4a and the movable contact 6, repulsive forces are generated. This repulsive force becomes a driving force for opening the movable contact 6. At the time of instantaneous interruption with a large accident current such as a short-circuit accident, the movable contact 5 opens when the driving force becomes larger than the biasing force of a spring (not shown) pressing the movable contact 6 in the contact closing (ON state) direction. Begin to. When the contact is opened, an arc is generated between the fixed contact 3 and the movable contact 5, and the arc length increases as the opening operation of the movable contact 6 proceeds.

  In this Embodiment 1, since the 1st conductor part 4a which gives repulsive force to the movable contact 6 is inserted to the lower part of the crossbar 7, as shown in FIG. 1, it is movable with the 1st conductor part 4a. The opposing length with the contact 6 is extended and the repulsive force is increased. Therefore, the opening speed of the movable contact 6 at the initial stage of opening is increased. For this reason, the arc length is also increased, and the arc resistance is increased from the beginning of the opening, and the current limiting performance is enhanced. As another effect, since the first conductor portion 4a applies a magnetic driving force in the direction of the arc extinguishing device 11 (right direction) to the generated arc, the length of the first conductor portion 4a is extended. As a result, the magnetic driving force also increases. As a result, it becomes easy to take in the arc to the arc extinguishing device 11 arranged on the front surface (in the direction of the terminal on the power supply side) of the rotating contact of the movable contact, and the arc voltage is improved (generation of electrode effect voltage) and melting by arc division. Current limiting performance is enhanced by increasing the resistance of the arc itself by arc cooling by latent heat.

  For the generated arc, in addition to the magnetic driving force from the current flowing through the conductor described above, the flow of high-temperature gas generated by the arc generation in the direction of the exhaust port 12 and further the consumption of the ferromagnetic material. The magnetic attraction force of the arc extinguishing device 11 made of the arc plate 10 is mentioned. Regarding the magnetic attraction force, as shown in FIGS. 1 and 2, the arc extinguishing plate 10a on the lower side of the figure among the plural arc extinguishing plates 10 constituting the arc extinguishing device 11 is opened around the contact point position. The magnetic attraction force is applied to the arc from the very initial stage, so that it can be easily taken into the arc extinguishing device 11.

  Through the above operation, the movable contact 6 in FIG. 2 is opened, and the interruption is completed. Until completion, the arc is in a state of being taken into the arc extinguishing device 11, and the current limiting performance is enhanced by the arc dividing effect. In the state after the series of arcs described above is generated, the steam generated from the insulator 9 always acts on the arc, and the arc diameter is compressed to increase the arc resistance to improve the current limiting performance. Yes. As described above, it is possible to maintain a high arc voltage by increasing the arc resistance abruptly immediately after opening the electrode, and to increase the current limiting performance to limit the current peak and passing energy. Performance is obtained.

  As described above, according to the first embodiment, the turning angle of the turning connection portion A between the first conductor 4a and the second conductor 4b is set to an acute angle, and the second conductor portion serving as a suction conductor for the movable contact 6 is used. By inclining 4b with respect to the first conductor portion 4a of the repulsive conductor and making it non-parallel, the space of the arc extinguishing device 11 disposed above the second conductor portion 4b is expanded, and further to the vicinity of the contact contact position An arc extinguishing plate 10 can be arranged. By expanding the space of the arc extinguishing device 11, it is possible to increase the number of arc extinguishing plates 10 arranged without increasing the volume of the arc extinguishing plate 10 itself or reducing the thickness of one plate. As a result, an electromagnetic attractive force in the direction of the arc extinguishing device 11 is applied to the arc from the beginning of the opening, the cooling performance is improved by increasing the volume of the arc extinguishing device 11 itself, and the number of arc breaking points by increasing the number of arc extinguishing plates 10 is increased. Increases the blocking performance. Further, the arc taken in the arc extinguishing device 11 can be prevented from returning to the contact peripheral space.

  Further, the fact that the folding angle of the folding connection portion A is an acute angle makes it possible to insert an electric circuit for generating a repulsive force to the lower part of the crossbar 7 and increase the electromagnetic repulsive force at the time of opening. It becomes possible. This increases the initial opening speed and improves current limiting performance. 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. For this reason, the product packaging can also be reduced in volume and volume. Furthermore, it is possible to reduce the burden on the line to which the circuit breaker is connected, other circuit breakers connected to the circuit breaker, and the load.

Embodiment 2. FIG.
Next, a circuit breaker according to Embodiment 2 of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same or equivalent part through each figure and each embodiment. In the figure, the inclined portion of the second conductor portion 4b constituting the fixed contact 4 has a shape having an obtuse angle convex portion 4c as a portion bent upwardly in the opening direction of the movable contact 6. Yes. Others are the same as in the first embodiment. By setting it as the above structures, it becomes possible to adjust the height of the 2nd conductor part 4b. The height of the second conductor portion 4b affects the opening electromagnetic force generated in the movable contact 6 and the magnetic driving force in the direction of the arc extinguishing device 11 (see FIG. 2). These electromagnetic forces can be arbitrarily designed by adjusting the height of the conductor portion 4b.

  Hereinafter, in detail, with respect to the opening electromagnetic force, since the energization direction of the second conductor portion 4b and the movable contact 6 is the same direction, an attractive force acts between the two conductors during energization. Therefore, when the movable contact 6 is below the second conductor portion 4b, a force is generated in the direction of pulling the movable contact 6 upward, that is, opening the pole. The magnetic driving force of the arc will be described. When the movable contact 6 opens and an arc is generated between the contacts, the magnetic field generated by the current flowing through the second conductor portion 4b is linked to the arc. For example, when the external connection terminal 8 is on the high voltage side (+ side) and a current flows, the magnetic field generated from the second conductor portion 4b is linked to the arc from the back of the page to the front side, and the right side of the figure. A force is generated in the direction (direction of the arc extinguishing device 11 shown in FIG. 2).

  The opening electromagnetic force of the movable contact 6 and the magnetic driving force of the arc are strengthened when the height of the second conductor portion 4b is increased, but the space of the arc extinguishing device 11 is reduced by the height. As a result, the effect of dividing the arc to increase the arc voltage and the effect of cooling the arc to limit energy are reduced. Therefore, by changing the height of the second conductor portion 4b, it is possible to adjust the effect of electromagnetic force and the effect of taking in the arc by the arc extinguishing device 11. In the above example, the description has been given by providing only one convex portion 4c of the second conductor portion 4b. However, two or more convex portions having an obtuse angle may be provided upward. Further, the convex portion 4c may be curvedly formed, that is, curved upward.

  As described above, according to the second embodiment, the obtuse angle convex part 4c is provided on the inclined part of the second conductor part 4b upward, that is, as a part bent convexly in the opening direction of the movable contact 6. Thus, the height of the second conductor portion 4b can be adjusted. For this reason, it becomes possible to increase the magnetic driving force toward the arc extinguishing device 11 of the arc positioned below the second conductor portion 4b, and the interruption performance is improved.

Embodiment 3 FIG.
Next, a circuit breaker according to Embodiment 3 of the present invention will be described with reference to FIGS. In the first embodiment, the first conductor portion 4a is inserted into the lower portion of the crossbar 7 with the folded connection portion A serving as the folded portion of the fixed contact 4 at an acute angle, and the vacant upper space is extinguished. In the third embodiment, the crossbar 7 is extended in the direction of the movable contact 5 in the vacant space. In the drawing, the end of the cross bar 7 on the movable contact 5 side extends to the vicinity of the contact contact position, and the end of the cross bar 7 on the movable contact 5 side has a high temperature such as a resin material or a fiber material. When exposed, an insulator 14 that is a source of pressure gas is affixed. Further, a part of the arc extinguishing plate 10 provided above the fixed contact 4 has a short left side in the drawing so as not to interfere with the cross bar 7. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  In the third embodiment configured as described above, similarly to the first embodiment, the first conductor portion 4 a that gives a repulsive force to the movable contact 6 is inserted to the lower portion of the crossbar 7. Therefore, the opposing length of the movable contact 6 and the first conductor portion 4a is extended, and the repulsive force is increased. Therefore, the opening speed of the movable contactor 6 at the initial stage of opening is increased to increase the arc length, and the arc resistance is increased from the initial stage of opening to increase the current limiting performance. Further, since the first conductor portion 4a applies a magnetic driving force to the arc generated in the direction of the arc extinguishing device 11 (right direction), the magnetic driving force is increased by extending the length of the first conductor portion 4a. Increase. As a result, it is easy to incorporate the arc into the arc extinguishing device 11, and the current limiting performance is enhanced by the improvement of the arc voltage (generation of the electrode effect voltage) by arc division and the arc cooling by the latent heat of fusion.

  For the generated arc, in addition to the magnetic driving force from the current flowing through the conductor, the flow of high-temperature hot gas in the direction of the exhaust port generated by the generation of the arc, and the ferromagnetic material The magnetic attraction force of the arc extinguishing device 11 comprising the arc extinguishing plate 10 is mentioned. In the third embodiment, the crossbar 7 is expanded to the vicinity of the contact point position, so that there is no space on the side opposite to the arc traveling direction (the arc extinguishing device 11 direction) and the crossbar 7 is extinguished. Since the insulator 14 serving as a pressure generation source is provided at the end facing the arc device 11, the pushing force in the traveling direction is strengthened. Through the above operation, the arc extinguishing chamber is in a state where the movable contact 6 of FIG. 9 is opened, and the interruption is completed.

  As described above, according to the third embodiment, the cross bar 7 extends in the direction of the movable contact 5, and gas is applied to the end of the cross bar 7 on the movable contact 5 side at a high temperature such as a resin material or a fiber material. By providing the insulator 14 which is a generation source of the generated pressure gas, gas is generated from the insulator 14 when an arc is generated, and the arc driving force in the direction of the arc extinguishing device 11 is increased to improve the interruption performance. An effect is obtained.

  In the first to third embodiments, the case where the movable contact 6 is rotatably supported by the rotating shaft 6a has been described. However, the configuration of the support portion of the movable contact 6 and the opening / closing mechanism are described in the embodiment. However, the present invention is not limited to those exemplified above. Moreover, although the 1st conductor part 4a of the stationary contact 4 was made into the general T shape, this shape is not necessarily limited to a T shape. Furthermore, although the case of a three-phase configuration has been described, the number of phases is not limited to three.

  DESCRIPTION OF SYMBOLS 1 Base, 2 Cover, 3 Fixed contact, 4 Fixed contact, 4a 1st conductor part, 4b 2nd conductor part, 4c Convex part, 5 Movable contact, 6 Movable contactor, 6a Rotating shaft (support part), 7 Cross Bar, 8 External connection terminal, 9 Insulator, 10 Arc extinguishing plate, 11 Arc extinguishing device, 12 Exhaust port, 13 Barrier, 14 Insulator, A Folded connection part.

Claims (6)

  A fixed contact is provided, and the first contact portion is arranged so that a current flows in the opposite direction to the movable contact when the pole is closed, and one end portion is connected and closed so as to be folded back from the end portion of the first conductor portion. A stationary contact having a second conductor portion disposed so that a current flows in the same direction as that of the movable contact and having an external connection terminal on the other end side, and the first conductor portion; The folded connection portion with the second conductor portion is formed at an acute angle when viewed from the side, and the other end portion side of the second conductor portion is inclined so as to gradually move away from the first conductor portion. Circuit breaker to do.   The first conductor portion has two opposite directions in the direction intersecting the first direction at a position extending a predetermined dimension in the first direction facing the support portion side of the movable contact from the fixed contact. The second conductor portion is formed by two pieces whose end portions are parallel to each other, and the tip thereof is connected to each of the two ends of the first conductor portion, and the connection The other end portion extends from the portion in a direction opposite to the first direction so as to be folded at an acute angle when viewed from the side and inclined with respect to the first conductor portion in the opening direction of the movable contact. The circuit breaker according to claim 1.   A crossbar for opening and closing the movable contact is provided on the support portion side of the movable contact, and the folded connection portion of the fixed contact is inserted in the vicinity of an extension portion of a motion locus when the crossbar is closed. The circuit breaker according to claim 1 or 2, wherein the circuit breaker is provided.   4. The circuit breaker according to claim 2, wherein the inclined portion of the second conductor portion has a portion bent convexly in the opening direction of the movable contact. 5.   5. The circuit breaker according to claim 4, wherein the convex bent portion is formed in the vicinity of the portion that turns back at an acute angle.   The circuit breaker according to any one of claims 2 to 5, wherein an insulator for generating gas by an arc is provided at an end of the cross bar on the movable contact side.

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