JP2006024428A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker capable of reducing its size by reducing the stroke of movable contact in opening/closing direction in an arc extinction space without shortening a contact opening/closing distance. <P>SOLUTION: An operation shaft, penetrating through a separation wall 21 transmitting an opening/closing movement of an opening/closing mechanism part 15 to a movable contact 3, has a hollow pressing member 17 pressing the movable contact 3 in a direction of separating the movable contact from fixed contacts 6, 7 at separating operation by interlocking with the opening/closing movement of the opening/closing mechanism part 15; a press fitting spring of which, one end is engaged with the pressing member 17, and the other end is engaged with the movable contact 3, arranged in a hollow part of the pressing member 17, energizing the movable contact 3 toward the fixed contacts 6, 7; a cylinder-shaped cover member 16 sliding movement capably arranged on an outer peripheral face or an inner peripheral face of the pressing member 17, of which, one end is fixed to the movable contact 3; and an arc extinction space communicating opening 26 making the inside space of the cover member 16 communicate with the arc extinction space. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a circuit breaker that cuts off a current when an overcurrent flows in an electric circuit, and more particularly to a bridged circuit breaker that improves the breaking performance when a large current is cut off.

  In the conventional circuit breaker, for example, as shown in the seventh paragraph of Patent Document 1 and FIG. 2, the center hole in the vertical direction (moving contact opening / closing operation direction) of the fixed gauge attached to the casing of the circuit breaker Insert a pushbutton into the side wall of the fixed gauge and the port provided on the side of the pushbutton so that the contact bridge (movable contact) can penetrate, and the contact bias is applied between the bottom of the fixed gauge and the contact bridge. A small auxiliary assembly is formed by arranging a spring (contact pressure spring). As a result, the assemblability is improved. Further, as shown in the ninth paragraph of FIG. 3 and FIG. 3, in order to reduce the height of the circuit breaker (the dimension in the direction of opening and closing the movable contact), the shape of the downward projecting portion at the bottom of the housing The bottom of the fixed gauge protrudes so as to fit into the corresponding central hole.

JP-A-6-68771

  The conventional circuit breaker is configured as described above, and a contact pressure spring is provided between the bottom wall surface of the housing and the movable contact, and this contact pressure spring does not become a predetermined dimension or less even during compression. There has been a problem that the dimension (height direction dimension) of the movable contact opening / closing operation direction of the arc extinguishing space cannot always be reduced. In addition, the size of the central hole corresponding to the shape of the downward projecting portion of the bottom of the housing depends on the shape of the bottom of the housing provided in accordance with the shape of the external rail to attach the circuit breaker to the external rail. To do. Therefore, when it is necessary to increase the contact pressure spring diameter, such as a circuit breaker with a large current carrying capacity, there is a problem that this central hole cannot be used to reduce the height of the circuit breaker. It was.

  The present invention has been made in order to solve the above-described problems of the prior art, and reduces the dimension of the movable contact opening / closing operation direction of the arc extinguishing space without reducing the contact opening distance. An object of the present invention is to provide a circuit breaker that can be miniaturized.

  A circuit breaker according to the present invention includes a movable contact having first and second movable contacts, and first and second fixed contacts having first and second fixed contacts that form a contact pair with the first and second movable contacts, respectively. An opening / closing mechanism portion disposed on the opposite side of the movable contact of the first and second fixed contacts, an opening / closing mechanism portion storage space for storing the opening / closing mechanism portion, and the first and second fixed contacts. A partition that separates at least the fixed contact side end and the arc extinguishing space that houses the movable contact; and the partition that passes through the partition and is disposed between the first fixed contact and the second fixed contact. A circuit breaker comprising an operation shaft for transmitting an opening / closing operation of the opening / closing mechanism to the movable contact, wherein the operation shaft is connected to the opening / closing operation of the opening / closing mechanism and moves the movable contact to the fixed contact Hollow to push away from A pressure member, one end of which is engaged with the pressing member, and the other end of which is engaged with the movable contact, and is disposed in the hollow portion of the pressing member, and urges the movable contact toward the fixed contact. A spring, a cylindrical cover member that is slidably disposed on the outer peripheral surface or the inner peripheral surface of the pressing member, and one end of which is fixed to the movable contact, the inner space of the cover member, and the arc extinguishing An arc extinguishing space communication opening that communicates with the space is provided.

  According to such a configuration, since the contact pressure spring does not get in the way when the movable contact is separated from the fixed contact, the dimension in the movable contact opening / closing operation direction of the arc extinguishing space without shortening the contact separation distance. As a result, the circuit breaker can be reduced in size.

Embodiment 1 FIG.
1-4 is a figure for demonstrating the circuit breaker by Embodiment 1 of this invention, More specifically, FIG. 1 is partially broken and shows an inside and movable contact | release separation ( FIG. 2 is a perspective view showing the main part of FIG. 1, (a) is a front view, (b) is a bottom view, and FIG. 3 is a main part of FIG. FIG. 4 is a cross-sectional view showing a main part of FIG. 1 and showing a state in which a contact pressure spring is extended.

As shown in FIG. 1, first and second movable contacts 1 and 2 are fixed to both ends of the movable contact 3, respectively, and arc horns 4 and 5 is provided. The first and second fixed contacts 6, 7 that form a contact pair with the movable contact 3 have first and second fixed contacts 8, 9 that form a contact pair with the first and second movable contacts 1, 2. Each is fixed. The first and second fixed contacts 6 and 7 are arranged in a substantially U-shaped manner so as to face each other laterally with an interval therebetween, so that an electromagnetic repulsive force is generated between the first and second fixed contacts 6 and 7 when the short-circuit current is interrupted. ing.
The electric circuit during energization of this circuit breaker is composed of one terminal portion 12, relay portion 14, first fixed contact 6, movable contact 3, second fixed contact 7, and the other terminal portion 13. Is done.

  The relay unit 14, the opening / closing mechanism 15, the first and second fixed contacts 6, 7, the movable contact 3, the operating shaft that transmits the opening / closing operation of the opening / closing mechanism 15 to the movable contact 3, and the plurality of arc-extinguishing plates 18 The opening / closing mechanism housing space for housing the opening / closing mechanism 15 and the arc extinguishing space for housing the first and second fixed contacts 6, 7 and the movable contact 3 are stored in the casing 100. It is separated by. The plurality of arc extinguishing plates 18 are disposed in the vicinity of both ends of the movable contact 3 to extinguish arcs generated when the movable contact 3 is separated from the fixed contacts 6 and 7. In FIG. 1, the right arc-extinguishing plate is not shown in the drawing. An arc extinguishing side plate 19 is disposed on the side of the arc extinguishing plate 18. Further, the casing 100 is provided with exhaust ports 111 and 112.

The operating shaft is linked to the opening / closing operation of the opening / closing mechanism section 15, and a hollow pressing member 17 that presses the movable contact 3 in the direction of opening from the fixed contacts 6, 7 during the opening operation, and one end to the pressing member 17, A contact pressure spring (not shown in FIG. 1) whose other ends are respectively engaged with the movable contact 3 and arranged in the hollow portion of the pressing member 17 and urges the movable contact 3 toward the fixed contacts 6 and 7. And a cylindrical cover member 16 that is slidably disposed on the outer peripheral surface of the pressing member 17 and that has one end fixed to the movable contact 3, and communicates the inner space of the cover member 16 with the arc extinguishing space. And a through hole 26 corresponding to the arc extinguishing space communication opening.
That is, a cylindrical cover member 16 is fixed to the movable contact 3, and a hollow pressing member 17 that is partially or entirely fitted inside the cover member 16 is disposed. The pressing member 17 and the movable contact 3 are urged so as to be attracted by a contact pressure spring (not shown in FIG. 1) provided in the internal space (hollow portion) of the hollow pressing member 17. The pressing member 17 penetrates the partition wall 21 and is linked to the opening / closing operation of the opening / closing mechanism unit 15 in the opening / closing operation direction of the movable contact 3 (the direction indicated by the arrow in FIG. And the movable contactor 3 is pressed in a direction to separate from the fixed contacts 6 and 7 when the opening / closing mechanism 15 is opened.
The opening / closing mechanism 15 is connected to a manual operation handle 110 that extends to the outside of the housing 100 on the side opposite to the pressing member 17.
The casing bottom wall surface 101 in the direction (downward in FIG. 1) in which the movable contact 3 is separated (opened) serves as a mounting surface of the circuit breaker, and the center of the casing bottom wall surface 101 The part is provided with a recess for attaching the circuit breaker to the external rail.

When such a circuit breaker interrupts a large current such as a short-circuit current, the current concentration between the contact pairs 1, 8, 2, and 9 is earlier than the switching mechanism unit 15 is operated by a command from the relay unit 14. And the electromagnetic repulsive force between the fixed contact 6 and 7 conductor and the movable contact 3 conductor (hereinafter referred to as contact points 1 and 8, 2 and 9). And the electromagnetic repulsive force between the fixed contacts 6 and 7 conductor and the movable contact 3 conductor are referred to as the electromagnetic repulsive force between the contacts 3, 6, 3 and 7). The contact 3 moves to the housing bottom wall surface 101 side, and the contacts 1, 8, 2 and 9 are separated. Accordingly, arcs are generated between the two contact pairs 1, 8, 2, and 9, respectively, and these arcs are caused by the self-current electromagnetic force and the pressure gradient generated in the arc extinguishing space. 18 are driven, respectively, and divided and extinguished.
In the present embodiment, the electromagnetic repulsive force between the above-described fixed contact 6 and 7 conductor and the movable contact 3 conductor and the force for driving the arc generated between the contact pairs 1, 8, 2 and 9. In the U-shaped loops of the substantially U-shaped stationary contacts 6 and 7, a core 10 in which magnetic plates are laminated is provided.

Next, the operation axis will be described in detail with reference to FIGS.
A through hole 26 corresponding to an arc extinguishing space communication opening that communicates the hollow portion of the cover member 16 and the arc extinguishing space is formed at the center of the movable contact 3. The contact pressure spring 22 is disposed in the internal space (hollow part) of the pressing member 17, and one end thereof is engaged with the movable contact 3 by the pin 23, and the other end is engaged with the pressing member 17 by the pin 24. Yes.
The pressing member 17 and the movable contact 3 are configured to be attracted to each other by the contact pressure spring 22, that is, the contact pressure spring 22 biases the movable contact 3 toward the fixed contact, The pressing member 17 is engaged with the opening / closing mechanism portion 15 through a hole 17a provided on the counter movable contact side (opposite side of the movable contact 3), and the opening / closing mechanism portion 15 connects the pressing member 17 to the opening / closing mechanism portion. The movable contacts 1 and 2 come into contact with the fixed contacts 8 and 9 to be closed by pulling them up to the 15 side. Open from 9 to open the pole. Further, the cover member 16 is engaged with the movable contact 3 by the claw portion 25 and is fixed to the movable contact 3, and moves integrally with the movable contact 3.

  Here, as described above, when the movable contact 3 is opened by the electromagnetic repulsive force between the contacts 3, 6, 3, and 7 prior to the operation of the opening / closing mechanism section 15, as shown in FIG. The pressure spring 22 extends, and a part of the contact pressure spring 22 moves out of the hollow portion of the pressing member 17. At this time, if the cover member 16 is not present, the contact pressure spring 22 portion that has moved out of the hollow portion of the pressing member 17 directly faces the arc generated between the contact pairs 1, 8, 2, and 9, and Damaged by the resulting heat. That is, the cover member 16 is mainly provided to protect the contact pressure spring 22 from the arc, that is, to cover the contact pressure spring 22.

  If the contact pressure spring 22 is housed inside the pressing member 17 as in the present embodiment, there is no need to provide the contact pressure spring 22 between the housing bottom wall surface 101 and the movable contact 3 as in the prior art. Therefore, it is possible to open the movable contact 3 to the bottom wall surface 101 of the casing, so that the arc-extinguishing space required to secure a contact separation distance necessary to obtain a desired breaking performance can be obtained. The dimension in the contact opening / closing operation direction can be reduced. In particular, when the casing bottom wall surface 101 is used as the mounting surface of the circuit breaker as in the present embodiment, a recess for mounting the circuit breaker to the external rail is provided on the bottom surface of the casing. Such an arrangement of the contact pressure spring 22 is particularly effective for reducing the height dimension of the circuit breaker.

  In a circuit breaker that cuts off a large current, an arc having very large energy is generated. Therefore, an arc extinguishing space in which an arc extinguishing device such as an arc extinguishing plate 18 for processing the arc is disposed, an opening / closing mechanism 15 and The opening / closing mechanism housing space in which the relay unit 14 is arranged is separated by a partition wall 21 to prevent arc heat and the accompanying melt from reaching the opening / closing mechanism unit 15 and the relay unit 14 to wear them. Yes.

  However, when the partition wall 21 exists, a pressure difference is generated between the arc extinguishing space in which the movable contact 3 is accommodated and the opening / closing mechanism portion accommodating space in which the opening / closing mechanism portion 15 is accommodated when a large current is interrupted. This pressure difference becomes a force that pushes the pressing member 17 provided penetrating the partition wall 21 toward the opening / closing mechanism portion storage space. Further, since the movable contact 3 and the cover member 16 cover the lower end of the pressing member 17 in a cap shape, if there is no through hole 26 provided in the central portion of the movable contact 3, the arc extinguishing is performed. As the pressure in the space rises, the movable contact 3 receives a force toward the pressing member 17, and the opening operation due to the electromagnetic repulsion between the contacts 3, 6, 3, and 7 is hindered. An ignition may occur.

Therefore, in the present embodiment, by providing the through hole 26 in the movable contact 3, the pressure difference between the arc extinguishing space and the inner space of the cover member 16 is alleviated, and the occurrence of the obstruction of the opening operation is prevented. It is out. Therefore, the contact can be surely opened by the electromagnetic repulsive force between the contacts 3, 6, 3, and 7, and an excellent breaking performance can be realized.
Further, in the present embodiment, the arc extinguishing space communication opening (through hole 26) that communicates the inner space of the cover member 16 and the arc extinguishing space is formed with the inner space of the cover member 16 at the center of the movable contact 3. It is provided in a portion that partitions the arc space so as to open toward the bottom wall surface 101 of the housing. This is because by providing the through hole 26 at a position that does not face the arc, the temperature of the hot gas caused by the arc flowing from the through hole 26 is lowered to prevent the contact pressure spring 22 from being worn. When the arc extinguishing space communication opening (through hole 26 in the present embodiment) is provided at the portion of the cover member 16 facing the arc generated between the contact pairs 1, 8, 2, and 9, the high temperature caused by the arc This gas flow flows into the space in which the contact pressure spring 22 is accommodated, and damage such as the spring becoming loose occurs. As a result, re-energization after the short-circuit current is interrupted and abnormal temperature rise at the time of re-energization are caused.

As described above, in the present embodiment, by providing the arc extinguishing space communication opening (through hole 26) that communicates the inner space of the cover member 16 and the arc extinguishing space, the pressure in the arc extinguishing space when a large current is interrupted is provided. The movable contactor 3 is prevented from receiving a force in the closing direction due to the rise and delaying the opening operation. However, the pressure difference between the hollow portion of the pressing member 17 that is in communication with the high-pressure arc extinguishing space through the inner space of the cover member 16 and the opening / closing mechanism housing space has not been alleviated. The pressure difference between the hollow portion of the pressing member 17 and the opening / closing mechanism portion storage space acts so as to prevent the opening / closing mechanism portion 15 from opening.
The movable contact 3 opened by the electromagnetic repulsive force between the contacts when the large current is interrupted decreases the electromagnetic repulsive force (opening force) with the decrease in the instantaneous value of the accident current in the latter half of the interrupting operation. It becomes smaller than the force (closing force) of the pressure spring 22, and the closing operation is started. Along with this closing operation, the distance between the contacts becomes smaller, and when the distance becomes smaller than a predetermined distance between the contacts, the arc is re-ignited between the contacts. If the opening / closing mechanism 15 pushes the pressing member 17 down to the predetermined distance between the contacts before the distance between the predetermined contacts becomes smaller than the predetermined distance between the contacts, arc re-ignition can be prevented, and the interruption can be completed in a short time, A circuit breaker that can be used repeatedly can be realized by preventing wear of the arc extinguishing devices such as the fixed contacts 6 and 7, the movable contact 3, and the arc extinguishing plate 18.

  Therefore, in this embodiment, in order to relieve the pressure difference acting on the pressing member 17 that hinders the operation of the opening / closing mechanism 15 described above, the opening / closing that communicates the hollow portion of the pressing member 17 with the opening / closing mechanism housing space. A mechanism unit storage space communication opening 28 is provided. That is, as shown in FIGS. 3 and 4, an opening 28 penetrating the inside and the outside of the hollow pressing member 17 is provided in a portion of the pressing member 17 located on the opening / closing mechanism housing space side from the partition wall 21. Thereby, since the pressure difference acting on the pressing member 17 is relaxed, it is possible to reduce the force by which the operating shaft (pressing member 17) is pushed back to the opening / closing mechanism portion 15 side by the pressure increase in the arc extinguishing space when a large current is interrupted. The pressing member 17 can be immediately pushed down by the opening / closing mechanism 15, and a circuit breaker that cannot be interrupted due to the operation delay of the opening / closing mechanism 15 and hardly re-ignites can be realized.

  In the present embodiment, the arc extinguishing space communication opening (through hole 26) that communicates the inner space of the cover member 16 and the arc extinguishing space, and the hollow portion of the pressing member 17 and the open / close mechanism housing space are communicated. However, only the arc-extinguishing space communication opening (through hole 26) may be provided, and the pressure in the arc-extinguishing space when a large current is interrupted is shown. It is possible to prevent the movable contactor 3 from receiving a force in the closing direction due to the rise and delaying the opening operation, thereby preventing the contact from being interrupted.

Embodiment 2. FIG.
FIG. 5 is a view for explaining a circuit breaker according to Embodiment 2 of the present invention, and more specifically, a front view showing a main part.
In the first embodiment, the case where the through hole 26 corresponding to the arc extinguishing space communication opening is arranged in the movable contact 3 has been described. However, in the present embodiment, as shown in FIG. The slit 27 corresponding to the common opening was disposed on the wall surface parallel to the longitudinal direction of the movable contact 3 in the cover member 16. That is, a plurality of slits 27 extending from the side of the claw portion 25 at the end of the movable cover 3 side of the cylindrical cover member 16 are formed so that the arc extinguishing space communication opening does not face the arc generated between the contacts. .

Also in the present embodiment, as in the case of the first embodiment, a delay in the opening operation of the movable contact 3 due to a rise in pressure in the arc extinguishing space when a large current is interrupted can be prevented, and it occurs when the contact is released. The wear of the contact pressure bar 22 due to the arc can be prevented.
Furthermore, in the first embodiment, due to the conductor width of the movable contact 3, it may be difficult to ensure the area of the opening (through hole 26) necessary to sufficiently relieve the pressure difference between the inside and outside of the cover member 16. On the other hand, in the present embodiment, a sufficient opening area can be ensured by increasing the dimension of the slit 27 in the movable contact opening / closing operation direction, so that the contact spring 22 is not damaged. The pressure difference between the inside and outside of the cover member 16 can be sufficiently relaxed, and a delay in the opening operation of the movable contact 3 due to a pressure increase in the arc extinguishing space when a large current is interrupted can be prevented.
Further, by providing a slit 27 extending from the side of the claw 25 at the end of the movable cover 3 side of the cylindrical cover member 16 as shown in FIG. 5, the claw 25 provided on the cover member 16 can be moved. The elasticity for engaging with the contact 3 can be applied to the end of the cover member 16 on the movable contact 3 side.

  In each of the above embodiments, the cover member 16 is slidably disposed on the outer peripheral surface of the pressing member 17. However, the cover member 16 is slidably disposed on the inner peripheral surface of the pressing member 17. The same effect can be obtained.

  In each of the above-described embodiments, the case where the pressing member 17 is configured to directly press the movable contact 3 during the opening operation of the opening / closing mechanism 15 has been described. However, the present invention is not limited to this. For example, the pressing member 17 may be configured to indirectly press the movable contact 3 by pressing the cover member 16. In this case, the pressing member 17 may be configured so that the cover member 16 penetrates the partition wall 21 without penetrating the partition wall 21.

  In each of the above-described embodiments, the case where the present invention is mainly applied to a single-pole circuit breaker has been described. However, it goes without saying that the present invention can also be applied to a multi-pole circuit breaker, and similar effects can be obtained. Yes.

It is a perspective view which partially fractures | ruptures the circuit breaker by Embodiment 1 of this invention, and shows an inside. The principal part of the circuit breaker by Embodiment 1 of this invention is shown, (a) is a front view, (b) is a bottom view. It is sectional drawing which shows the principal part of the circuit breaker by Embodiment 1 of this invention, and represents the state which the contact pressure spring contracted. It is sectional drawing which shows the principal part of the circuit breaker by Embodiment 1 of this invention, and represents the state which the contact pressure spring extended. It is a front view which shows the principal part of the circuit breaker by Embodiment 2 of this invention.

Explanation of symbols

  1, 2 1st and 2 movable contacts, 3 movable contacts, 4, 5 arc horns, 6, 7 1st and 2 fixed contacts, 8, 9 1st and 2 fixed contacts, 10 cores, 12, 13 terminals, 14 Relay part, 15 Opening / closing mechanism part, 16 Cover member, 17 Press member, 18 Arc extinguishing plate, 19 Arc extinguishing side plate, 21 Bulkhead, 22 Contact pressure spring, 23, 24 Pin, 25 Claw part, 26 Through hole, 27 Slit , 28 Opening and closing mechanism section storage space communication opening, 100 housing, 101 housing bottom wall surface, 110 handle, 111, 112 exhaust port

Claims (3)

A movable contact having first and second movable contacts;
First and second stationary contacts having first and second stationary contacts forming contact pairs with the first and second movable contacts, respectively;
An opening / closing mechanism portion disposed on the opposite side of the movable contact of the first and second fixed contacts;
A partition that separates an opening / closing mechanism housing space that houses the opening / closing mechanism, an arc extinguishing space that houses at least the fixed contact side end of the first and second stationary contacts, and the movable contact;
In a circuit breaker comprising an operation shaft that passes through the partition wall and is disposed between the first fixed contact and the second fixed contact and transmits an opening / closing operation of the opening / closing mechanism to the movable contact.
The motion axis is
A hollow pressing member that presses the movable contact member in a direction to separate from the fixed contact member at the time of opening operation in conjunction with the opening / closing operation of the opening / closing mechanism unit,
A contact pressure spring having one end engaged with the pressing member and the other end engaged with the movable contact and disposed in the hollow portion of the pressing member, and biasing the movable contact toward the fixed contact;
A cylindrical cover member that is slidably disposed on the outer peripheral surface or inner peripheral surface of the pressing member, and one end of which is fixed to the movable contact;
A circuit breaker comprising an arc extinguishing space communication opening that communicates the inner space of the cover member and the arc extinguishing space. 2. The circuit breaker according to claim 1, wherein the arc extinguishing space communication opening is arranged on a wall surface of the cover member parallel to the longitudinal direction of the movable contact or on the movable contact. 3. The circuit breaker according to claim 1, further comprising an opening / closing mechanism portion storage space communication opening that communicates the hollow portion of the pressing member and the opening / closing mechanism portion storage space.

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