JP6234872B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker, and more particularly to an extinguishing device for extinguishing an arc generated between contacts.

  The circuit breaker generates an arc discharge between the contacts when interrupting the current. Since this arc discharge adversely affects the contact and the surroundings, the arc is extinguished in a short time by an arc extinguishing device.

  A general arc extinguishing device is a grid (magnetic iron plate) with a U-shaped notch through which a movable contact passes, stacked at an appropriate interval, and supported by an insulating support plate. Is fixed to the support plate by bonding or caulking. For this reason, many processes were required for the attachment work of a grid (magnetic iron plate), there existed a problem that an assemblability was bad and the number of parts increased.

  As a conventional technique for solving this problem, there is JP-A-8-227648 (Patent Document 1). Patent Document 1 describes a structure in which an insulator straddling a grid is integrally molded with a mold resin. Further, it is described that the auxiliary side wall is provided inside the side wall of the insulator, thereby reducing the space in the insulator and improving the arc extinguishing performance by the effect of narrowing the arc.

JP-A-8-227648

  In Patent Document 1, since the grid (magnetic iron plate) of the arc extinguishing device is covered with the auxiliary side wall (partition plate), the arc driving force is reduced at the time of opening and closing in the DC small current region (10 to 30 A), It is assumed that the arc cooling effect is weakened, and in that case, it becomes impossible to shut off.

  Therefore, there is a need for a circuit breaker that has a high breaking performance and also improves the breaking performance in the DC small current region.

  It is an object of the present invention to improve the deterioration of the breaking performance in a small current region where the arc driving force by the partition plate attached for improving the assembling performance and the arc extinguishing performance is small.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present invention includes a plurality of means for solving the above-described problems. For example, a fixed contact having a fixed contact, a movable contact having a movable contact, and driving the movable contact. An open / close mechanism that opens and closes the fixed contact and the contact portion of the movable contact, and an arc extinguishing device that extinguishes an arc generated between the fixed contact and the movable contact, and the arc extinguishing device is connected A case integrally formed of a pair of side walls and a mold resin having a pair of partition plates inside the side walls, and a plurality of magnetic iron plates. The partition plate surrounds the fixed contact and the movable contact. The magnetic iron plate is U-shaped, and the case holds the magnetic iron plate by inserting the magnetic iron plate along a groove provided on the opposing surface of the side wall, and the partition plate is notched. Two opposite sides of the U-shape of the magnetic iron plate Since the notch is configured to expose the movable contact terminal side.

  According to the present invention, the arc extinguishing has high short-circuit interruption performance, secures switching performance of a small DC current, has a structure in which only a magnetic iron plate is inserted, and can reduce the number of parts and improve the assembling work and the number of assembling work steps. A circuit breaker having the device can be provided.

It is a block diagram of the circuit breaker of the Example of this invention. It is a block diagram of the arc-extinguishing apparatus of the Example of this invention. It is a block diagram of the arc-extinguishing apparatus of the Example of this invention. It is a structure figure of the case simple substance used for the arc-extinguishing apparatus of the Example of this invention. It is a structure figure of the case simple substance used for the arc-extinguishing apparatus of the Example of this invention. It is explanatory drawing of the arc-extinguishing apparatus assembly of the Example of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a structural diagram of a circuit breaker of this embodiment, (A) is a perspective view, and (B) is a side sectional view. In FIG. 1, a circuit breaker includes a contact portion including a movable contact 2 of a movable contact and a fixed contact 3 of a fixed contact for interrupting a current of a main circuit, and an opening / closing mechanism portion for opening and closing the contact portion. 3, a tripping device 5 that trips the switching mechanism 3 under conditions such as overcurrent, and an arc extinguishing device 1 that cools and extinguishes the arc between the contacts when the contacts open.

  2 and 3 are structural diagrams of the arc extinguishing device of the present embodiment. 2A is a perspective view, and FIG. 2B is a cross-sectional view taken along the longitudinal center aa of FIG. 3A is a front view, FIG. 3B is a side view, and FIG. 3C is a rear view. In FIG. 2, the arc extinguishing device is configured by inserting a plurality of magnetic iron plates 8 into a case 6 that is integrally molded with a mold resin. As shown in FIG. 2B, the case 6 is provided with two partition plates 9 provided in parallel with the side wall 7 of the case 6 at a position sandwiching the contact portion that opens and closes. This arc extinguishing device is disposed so as to surround the fixed contact and the movable contact by a partition plate. Then, a notch 10 is provided in the lower part of the partition plate 9 in the vicinity of the fixed contact where the fixed contact 3 and the movable contact 2 abut, and a convex part 12 is provided in the magnetic iron plate 8 on the contact side, and the partition plate 9 is cut from the partition plate 9. The protrusion 12 of the magnetic iron plate is exposed through the notch 10.

  That is, the case holds the magnetic iron plate by inserting a magnetic iron plate along a groove provided on the opposing surface of the side wall, and the U-shaped opposite of the magnetic iron plate is opposed between the pair of side walls and the partition plate. Two sides, in other words, arm portions of the U-shaped magnetic iron plate are inserted to hold the magnetic iron plate. The partition plate has a notch and is configured such that two opposing sides of the U-shape of the magnetic iron plate are exposed to the movable contact side from the notch.

Thereby, the arc narrowing effect by the partition plate 9 has a high interrupting performance at the time of short circuit interruption, and the arc cooling effect can be interrupted by maintaining the arc cooling effect even by opening and closing in a small current region by exposing the magnetic iron plate 8. .

  4 and 5 show structural diagrams of the case 6 alone used in the arc extinguishing apparatus of the present embodiment. 4A is a perspective view, and FIG. 4B is a cross-sectional view taken along the longitudinal center aa of FIG. 5A is a front view, FIG. 5B is a side view, and FIG. 5C is a rear view.

  As described above, in FIG. 4B and FIG. 5A, the case 6 is provided with the two partition plates 9 provided in parallel to the side wall 7 of the case 6. It is the structure which provided the notch part 10 in the lower part. The case 6 has a protrusion 11 and the case 6 is configured as a magnetic iron plate holding case for holding the magnetic iron plate 8. The case 6 has an opening through which one of the surfaces orthogonal to the pair of side walls 7 can move the movable contact, and the other has an opening through which a magnetic iron plate can be inserted.

  FIG. 6 is an explanatory diagram of assembling the arc extinguishing device of this embodiment. FIG. 6 is a view showing a state in which the magnetic iron plate 8 is inserted into the case 6, and shows a perspective view of a longitudinal section in which one side of the side wall 7 of the case 6 is removed. As shown in FIG. 6, two opposite sides of the U-shape of the magnetic iron plate 8 are inserted between the side wall and the partition plate. At this time, since the notch 10 has a comb blade shape with the insertion side of the magnetic iron plate opened, it is easy to insert the magnetic iron plate 8 into the case 6, and the magnetic iron plate 8 is Can hold. Thereby, an arc extinguishing apparatus can be manufactured only by inserting, and assemblability and work man-hours can be improved.

  As described above, in this embodiment, the lower magnetic iron plate 8 near the contact portion between the fixed contact 3 and the movable contact 2 is not covered with the partition plate 9 but exposed. In order to cut off the arc within 10ms, it is important to cut off the arc with the second and third magnetic iron plates 8 from the contact point of the fixed contact 3 and the movable contact 2 from the opening speed of the movable contact. is there. By using this structure, the magnetic iron plate 8 that is first exposed to the arc at the time of opening can be arranged near the movable contact 2, and the arc driving force by the magnetic iron plate 8 is maintained even at a low DC current, and the arc cooling effect It is possible to increase.

  In alternating current, the timing of passing the zero point, that is, the timing when the current value becomes zero is periodically repeated because of the characteristics of the current change. Therefore, when AC is interrupted, the arc can be extinguished and interrupted by waiting for the zero point or the timing when the current value becomes zero and performing the arc extinguishing operation in accordance with this timing. However, since direct current does not pass through the zero point, it is generally known that arc extinction and interruption are more difficult than alternating current.

  In addition to this direct current characteristic, in the case of a small current, it is expected that arc extinguishing and interruption will become more difficult as described above.

  On the other hand, the structure of the present embodiment improves arc extinguishing and interruption performance even in the case of a small DC current.

  In the manufacture of the magnetic iron plate holder that is the molded case described in the present embodiment, it is necessary to devise the structure of the protrusion 11 and the notch 10 in order to facilitate the release from the mold. There is. For example, since it is necessary to hold the magnetic iron plate with an inclination with respect to the case, the protrusion 11 and the notch 10 associated therewith can make the notch portion with a small inclination angle longer in the comb blade shape, but the inclination angle becomes larger. As shown in FIG. 6, it is desirable to shorten the upper protrusion in consideration of release from the mold.

  As described above, in this embodiment, the fixed contact having a fixed contact, the movable contact having a movable contact, and the movable contact are driven to open and close the contact portion of the fixed contact and the movable contact. And an arc extinguishing device that extinguishes an arc generated between the fixed contact and the movable contact, and the arc extinguishing device includes a pair of connected side walls and a pair of partition plates inside the side walls. A case integrally molded with a mold resin, and a plurality of magnetic iron plates, arranged to surround the fixed contact and the movable contact by the partition plate, the magnetic iron plate is U-shaped, The case holds the magnetic iron plate by inserting the magnetic iron plate along a groove provided on the opposing surface of the side wall, and the partition plate has a notch and is opposed to the U-shape of the magnetic iron plate. A configuration in which a side is exposed from the notch to the movable contact side That.

  In this way, in addition to improving the assembly by mold resin integral molding, by providing a notch in the partition plate and exposing the magnetic iron plate, the arc cooling effect is maintained by opening and closing in a small current region, Moreover, the short-circuit breaking performance can be improved by the effect of narrowing the arc by the partition plate.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and includes various modifications. That is, the shape and arrangement of the component parts are not limited to the present embodiment, and may be appropriately changed within the spirit of the present invention.

1: arc extinguishing device, 2: movable contact, 3: fixed contact, 4: open / close mechanism,
5: Tripping device, 6: Case, 7: Side wall of case, 8: Magnetic iron plate,
9: Partition plate, 10: Notch, 11: Protrusion, 12: Convex

Claims (8)

A stationary contact with a stationary contact;
A movable contact with a movable contact;
An open / close mechanism for driving the movable contact to open and close the contact of the fixed contact and the movable contact;
An arc extinguishing device for extinguishing an arc generated between the fixed contact and the movable contact;
The arc-extinguishing device includes a pair of side walls connected to each other, a case integrally formed of a mold resin having a pair of partition plates inside the side walls, and a plurality of magnetic iron plates. And surrounding the movable contact,
The magnetic iron plate is U-shaped,
The case holds the magnetic iron plate by inserting the magnetic iron plate along a groove provided on the opposing surface of the side wall,
The partition plate has a notch , the notch is disposed in the vicinity of the fixed contact where the fixed contact and the movable contact abut, and two opposite sides of the U-shape of the magnetic iron plate are formed from the notch. A circuit breaker configured to be exposed to the movable contact side. The circuit breaker according to claim 1, wherein
The circuit breaker characterized in that the case holds the magnetic iron plate by inserting two U-shaped opposing sides of the magnetic iron plate between the pair of side walls and the partition plate. The circuit breaker according to claim 1 or 2 ,
The circuit breaker is characterized in that the notch in the partition plate has a comb blade shape . The circuit breaker according to any one of claims 1 to 3,
The circuit breaker, wherein the case has a protrusion for holding a magnetic iron plate . The circuit breaker according to any one of claims 1 to 4,
One of the surfaces orthogonal to the pair of side walls has an opening through which the movable contact can move, and the other has an opening through which the magnetic iron plate can be inserted . The circuit breaker according to any one of claims 1 to 5,
The circuit breaker, wherein the magnetic iron plate has a convex portion, and the convex portion is exposed to the movable contact side from the notch . An arc extinguishing device for extinguishing an arc generated between contacts used in a circuit breaker that interrupts an overcurrent or a short-circuit current flowing in an electric circuit,
A pair of side walls connected to each other and a pair of partition plates inside the side walls, comprising a case integrally molded with a mold resin, and a plurality of magnetic iron plates,
The magnetic iron plate is U-shaped,
The case holds the magnetic iron plate by inserting the magnetic iron plate along a groove provided on the opposing surface of the side wall,
The partition plate has a notch, the notch is disposed in the vicinity of the contact point, and two opposite sides of the U-shape of the magnetic iron plate are exposed from the notch to the inside of the partition plate. An arc extinguishing device characterized by comprising: A magnetic iron plate holding case for an arc extinguishing device that extinguishes an arc generated between contacts, used for a circuit breaker that interrupts an overcurrent or a short-circuit current flowing in an electric circuit,
A pair of connected side walls and a pair of partition plates inside the side walls;
Having a groove provided on the opposing surface of the side wall into which a magnetic iron plate can be inserted ;
Further, the partition plate has a notch , the notch is disposed in the vicinity of the contact point, and two opposing sides of the U-shaped opposite of the magnetic iron plate can be exposed to the inside of the partition plate from the notch. Is configured as
One of the surfaces orthogonal to the pair of side walls has an opening into which the magnetic iron plate can be inserted,
A magnetic iron plate holding case of an arc extinguishing device, characterized in that it is integrally molded with a mold resin .

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