JP5447024B2 - Circuit breaker - Google Patents

Description

  The present invention includes a first movable contact connected to an opening / closing mechanism, and a second movable contact facing the first movable contact and separated from the first movable contact by an electromagnetic repulsive force. Circuit breaker.

  When an overcurrent such as a short-circuit current flows for a circuit breaker for wiring, etc., a second movable contact is disposed opposite to the first movable contact using an electromagnetic repulsive force generated between two parallel conductors. A circuit breaker is known in which a current is cut off in a limited manner by rapidly separating the movable contact (see, for example, Patent Document 1).

  In this circuit breaker, the first movable contact is linked to the opening / closing mechanism and is driven to open / close, and the second movable contact facing the first movable contact in parallel is directed toward the closed side by the contact spring. Each movable contact is brought into contact with a contact point provided at the tip of the movable contact so as to face up and down, and the rear end side of each movable contact is pivotally supported via a support shaft. .

  Next, FIG. 3 shows a conventional assembly structure of the circuit breaker, and FIG. 4 shows an assembly structure of the second movable contact and its periphery in FIG. In FIG. 3, 1 is a circuit breaker body case, 2 is a power supply side terminal, 3 is a load side terminal, 4 is a first movable contact, 5 is a second movable contact, and 6 is the power supply side terminal 2. Arc extinguishing devices arranged in the main body case 1 side by side, 7 is a flexible lead wire connected to the first movable contact 4, and 8 is a connection between the power supply side terminal 2 and the second movable contact 5. A flexible lead wire 9 is a contact spring (torsion coil spring) that urges the second movable contactor 5 toward the closing side.

  Here, the first movable contact 4 has a contact 4a fixed to the tip thereof, and a flexible lead wire 7 is connected to the rear end opposite to the contact 4a, and the support shaft 4b is pivoted. The movable contact holder 4c is connected to an opening / closing mechanism (not shown).

  On the other hand, the second movable contact 5 is arranged on the bottom side of the main body case 1 in parallel with the first movable contact 4, and the contact 5 a fixed to the distal end side of the second movable contact 5 is the first contact. It faces the contact 4a of the movable contact 4. Further, as shown in the assembly diagram of FIG. 4, the second movable contactor 5 has a rear end portion pivotally supported on a support shaft 5c of a support frame 5b, and is supported between the support frame 5b and the support frame 5b. The second movable contact 5 is biased toward the first movable contact 4 in the closing direction by stretching a contact spring 9 of a torsion coil spring. Further, a flat braided wire or a stranded flexible lead wire 8 formed by converging and knitting soft copper fine wires is provided on the left and right side surfaces of the second movable contact 5 at the rear end of the second movable contact 5. The flexible lead wire 8 is connected by brazing, and is drawn to the bottom side of the main body case 1 so as to bypass the side of the second movable contact 5 as shown in the figure, and between the power supply side terminal 2. Wiring.

  With the above configuration, at the closed position shown in FIG. 5A, the contact urging force of the contact spring 9 presses the contact 5 a of the second movable contact 5 against the contact 4 a of the first movable contact 4. Contact pressure is applied between the contacts. In this closed state, the current i flows from the power supply side terminal 2 through the flexible lead wire 8 → the second movable contact 5 → the first movable contact 4 → the flexible lead wire 7 as shown by the arrow in the figure. .

  When an overcurrent such as a short circuit current flows in the main circuit in this closed state, an electromagnetic repulsive force is generated between the first movable contact 4 and the second movable contact 5 in which the current i flows in a relatively reverse direction. F1 and F2 are generated, and the first movable contact 4 rotates clockwise around the support shaft 4b as shown in FIG. 5 (b) in response to the electromagnetic repulsive force. 5 rotates counterclockwise against the spring force of the contact spring 9, and the contact 4a of the first movable contactor 4 and the contact 5a of the second movable contactor 5 begin to be rapidly separated from each other. Arc arc is generated in In addition, with the subsequent tripping operation of the opening / closing mechanism, the first movable contact 4 moves upward toward the opening position to further extend the arc arc, and the arc arc is transferred to the arc extinguishing device 6 (see FIG. 5). The current is cut off by limiting the current.

Japanese Patent Laid-Open No. 3-11518

  By the way, the circuit breaker having the above-described conventional configuration has the following problems in terms of the opening operation function. That is, for the current flowing through the second movable contact 5 as shown in FIG. 5B, the current flowing through the flexible lead wire 8 connected to the contact and routed between the power supply side terminal 2 Since the directions are opposite, the magnetic field φ1 generated by the current flowing through the flexible lead 8 and the magnetic field φ2 generated by the current flowing through the second movable contact 5 are reversed as shown in FIG. . As a result, an upward electromagnetic force F3, that is, a force for driving the second movable contact 5 toward the closing side is generated in the second movable contact 5. Since this electromagnetic force F3 is opposite to the electromagnetic force F2 described in FIG. 5 (a), the opening speed of the second movable contactor 5 is decelerated, and the second movable contact 5 depends on the overcurrent current value i. If the contactor 5 is not driven in the opening direction, the current breaker performance of the circuit breaker may be deteriorated.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a second movable contact between the second movable contact and a flexible lead wire routed around the side of the movable contact. An object of the present invention is to provide an improved circuit breaker capable of reducing the influence of electromagnetic force acting in the direction of decelerating the opening speed of the coil and improving the current limiting interruption performance.

In order to achieve the above object, according to the present invention, a first movable contact connected to an opening / closing mechanism and driven to open and close, and a contact spring arranged in parallel with the first movable contact to close the pole. The first and second movable contacts are provided with a contact point on the front end side with the rear end portion pivotally supported on the rotating shaft, and the second movable contact. In the circuit breaker in which the child is routed between the flexible lead wire connected to the rear end thereof to the side of the second movable contact and wired between the power source side terminal,
The second peripheral surface of the flexible leads and wiring between the movable contact and the power supply side terminal shall be covered with a flexible magnetic shield material (claim 1), the magnetic shield material is specifically Can be configured in the following manner.
(1) are those magnetic shield material has fine wires braided to the tubular focusing the magnetic material, the second movable contact to cover the magnetic shielding material in the flexible leads and the power supply-side terminal The wiring is routed between them (claim 2).
(2) the magnetic shield material is formed twisting together to focus the fine lines of the magnetic material on its peripheral surface as the core wire of the flexible lead wire, the flexible lead wire coated with this magnetic shield material The lead wiring is provided between the second movable contact and the power supply side terminal.

  According to the above configuration, the flexible lead wire connected to the second movable contact is magnetically shielded. As a result, the magnetic interference of the current flowing in the flexible lead wire with respect to the second movable contact is reduced compared to the conventional configuration without the magnetic shield material, and the opening speed of the second movable contact is reduced. The electromagnetic force acting in the direction to be generated can be greatly reduced. As a result, the opening speed of the second movable contact driven in the opening direction by the electromagnetic repulsive force generated between the first movable contact and the second movable contact when an overcurrent flows. It is possible to exhibit high current limiting performance while maintaining the above.

  Moreover, since this magnetic shield material has sufficient flexibility, it does not impair the function of the flexible lead wire and is integrated with the flexible lead wire, so that the space for arranging the magnetic shield material in the main body case is reduced. There is no need to secure it.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of 1st Example by this invention, Comprising: (a) is a structural diagram of an electric current interruption part, (b) is an external view of the flexible lead wire with a magnetic shielding material connected to the 2nd movable contact, (C) is a cross-sectional enlarged view of (b). It is a block diagram of 2nd Example by this invention, Comprising: (a) is an external view of a flexible lead wire with a magnetic shielding material, (b) is a cross-sectional enlarged view of (a). It is a conventional structure figure of the circuit breaker used as the implementation object of this invention. FIG. 4 is a perspective view of an assembly structure around a second movable contact in FIG. 3. It is explanatory drawing of the current limiting interruption | blocking operation | movement of the electric current interruption part in FIG. 3, Comprising: (a), (b) is a figure showing a closing and an open state, respectively. It is a schematic diagram showing the electromagnetic force which acts between the 2nd movable contactor / flexible lead wire at the time of the opening operation | movement of FIG.5 (b).

  Embodiments of the present invention will be described below based on the examples shown in FIGS. In the drawings of the respective embodiments, members corresponding to those in FIG.

  First, an embodiment according to claims 1 and 2 of the present invention will be described with reference to FIGS. In this embodiment, the flexible lead wire 8 routed between the rear end of the second movable contact 5 and the power supply side terminal 2 along the side of the second movable contact 5 is substantially omitted. The full length region is surrounded by a flexible magnetic shield material. The magnetic shield material is a magnetic braided wire 10 which is formed by converging iron thin wires, which are magnetic materials, and knitted into a tube shape. After the magnetic braided wire 10 is covered with the flexible lead wire 8, the flexible lead wire 8 is covered. Are connected to the power supply side terminal 2 and the second movable contact 5 by soldering.

  As a result, the magnetic field generated by the current i flowing through the flexible lead 8 is magnetically shielded, and most of the lines of magnetic force are confined inside the magnetic braided wire 10, thereby reducing magnetic interference with the second movable contact 5. The electromagnetic force F3 shown in FIG. 6 (electromagnetic force that drives the second movable contactor 5 to the closing side) is significantly reduced. As a result, the second movable contact driven in the opening direction by receiving the electromagnetic repulsive force F2 generated between the first movable contact 4 and the second movable contact 5 when an overcurrent flows. The opening speed of the child 5 can be maintained, and excellent current limiting interruption performance can be exhibited. In addition, since the magnetic braided wire 10 knitted with a thin wire has sufficient flexibility, the flexibility of the flexible lead wire 8 and thus the opening operation of the second movable contact 5 may be hindered. In addition, since it is integrated with the flexible lead wire 8, it is not necessary to secure an arrangement space for the magnetic shield material in the main body case of the circuit breaker.

  Next, a second embodiment according to claim 3 of the present invention is shown in FIGS. In this embodiment, a copper thin wire of the flexible lead wire 8 is used as a core wire 8a, and a large number of magnetic wires 8b made of iron fine wires made of a magnetic material are converged so as to surround the peripheral surface. The magnetic shield material is formed by twisting together with the core wire 8a.

  Thereby, the magnetic shield effect equivalent to Example 1 mentioned above is show | played, and the high current limiting interruption | blocking performance of a circuit breaker can be exhibited.

1: Main body case 2: Power source side terminal 4: First movable contact 5: Second movable contact 5a: Contact 5c: Support shaft 8: Flexible lead wire 8a: Core wire (copper thin wire)
8b: Magnetic wire (iron fine wire)
9: Contact spring 10: Magnetic braided wire

Claims (3)

A first movable contact that is opened and closed linked to the opening and closing mechanism, and a second movable contact that is arranged in parallel to the first movable contact and is biased toward the closing side by a contact spring; The first and second movable contactors have their rear end portions pivotally supported on the rotation shaft and are provided with contacts on the front end side, and the second movable contactors have flexible lead wires connected to the rear end portions thereof. In the circuit breaker routed to the side of the second movable contact and wired between the power supply side terminals,
Circuit breaker, characterized in that the peripheral surface of the wire and said flexible lead wire covered with a flexible magnetic shield material between said second movable contact and the power supply-side terminals. The circuit breaker according to claim 1, wherein are those magnetic shield material is braided to form a tube shape focuses the fine lines of the magnetic material, the said magnetic shield material on which is coated on the flexible lead wire A circuit breaker characterized in that the wiring is routed between the two movable contacts and the power supply side terminal. The circuit breaker according to claim 1, wherein the magnetic shielding material are thin lines twisting with focusing formed of a magnetic material on its peripheral surface as the core wire of the flexible lead, is covered with the magnetic shield material circuit breaker, characterized in that the lead wiring between the flexible lead the second movable contact and the power supply terminal.

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