JPH082915Y2 - Arc-extinguishing chamber structure of circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an arc-extinguishing chamber structure of a circuit breaker such as a circuit breaker having a contact device for rapidly moving a movable contact when a contact is opened due to an excessive current. It is about.

[Background Art] In a circuit breaker for wiring, which has an arc extinguishing chamber for extinguishing an arc generated when a fixed contact and a movable contact are separated, an exhaust passage for guiding an arc gas generated by an opening at the time of short circuit interruption to an exhaust port Conventionally, it has been formed of a molded product or a hollow pipe. In this case, when the exhaust passage is formed by a molded product, strength is required due to the arc gas pressure, so that there is a problem that the wall thickness of the molded product must be increased, and the exhaust passage is formed by a hollow pipe. In that case, there was a problem that parts dedicated to the passage were required.

[Object of the Invention] The present invention is provided in view of the above points,
By extending the arc sufficiently long in the arc extinguishing chamber, the arc voltage is increased to extinguish the arc,
The yoke, partition plate, and exhaust plate that make up the arc-extinguishing chamber also serve as the exhaust passage so that the arc gas pressure is not applied directly to the surrounding housing, and the yoke made of a magnetic material prevents the arc gas pressure from being applied to the exhaust passage. The present invention provides an arc-extinguishing chamber structure for a circuit breaker for wiring intended to provide strength.

DISCLOSURE OF THE INVENTION (Structure) A contact device according to the present invention is provided with a fixed contact in a circuit breaker having an arc extinguishing chamber for extinguishing an arc generated when a fixed contact and a movable contact are separated. A movable contactor having a contact plate body and a movable contact forming a contact portion together with the fixed contact, the movable contactor having a shape elongated in a direction substantially orthogonal to the opening / closing direction of the contact portion and energized in its longitudinal direction; A pair of drive coils, which are arranged on both sides of the fixed contact plate with the contact between them, to apply an electromagnetic force to the movable contact in the direction in which the contact opens when the contact is closed, and a drive coil made of a magnetic material. And a bridging piece that is magnetically short-circuited between the upper ends of the pair of leg pieces, which are arranged on both sides of the contact point and whose lower ends are in close contact with the upper surface of the contact plate body. Insert the U-shaped yoke with the However, it is equipped with a partition plate that prevents the arc from being pushed back and is closely attached to one end of the yoke, and an exhaust plate that exhausts the arc gas and is closely attached to the other end of the yoke. An arc extinguishing chamber is formed by a yoke, a partition plate, and an exhaust plate that extinguishes the arc by being urged by the electromagnetic force generated between the magnetic field generated around the contactor and the arc generated when the contact is opened. Then, by causing the magnetic field generated around the movable contact to act on the arc via the yoke, the arc can be sufficiently extended, and the arc voltage is increased to extinguish the arc.
The yoke, partition plate, and exhaust plate that form the arc-extinguishing chamber also serve as the exhaust passage so that the arc gas pressure is not directly applied to the surrounding housing, etc. It is characterized in that it has strength against the applied arc gas pressure.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 3, a contact device is provided at a fixed position in the housing 1,
An arc extinguishing chamber 3 is provided for extinguishing the arc generated by the contact device. 1 to 4, a contact device includes a fixed contact plate 12 having a fixed contact 11 and a movable contact 13 having a movable contact 13 forming a contact portion 10 together with the fixed contact 11.
14, a pair of drive coils 15 arranged on both sides of the fixed contact plate 12 so as to sandwich the fixed contact 11, both drive coils made of a magnetic material
A yoke 16 is provided so as to extend over 15.

As shown in FIG. 1, the fixed contact plate 12 has a fixed contact 11 on the upper surface of an intermediate portion in the left-right direction. The left half of the fixed contact plate 12 acts as an arc traveling plate. With this configuration, the lower end of the arc generated with the opening of the contact portion 10 can be run along the fixed contact plate 12 or the arc traveling plate. The front and rear sides of the fixed contact plate 12 each have a central axis orthogonal to the longitudinal direction of the fixed contact plate 12,
A U-shaped bent drive coil 15 having a downward opening is provided so as to sandwich the fixed contact 11. Further, the central axes of both drive coils 15 are located on the same straight line. The right end of the drive coil 15 is integrally connected to the right end of the fixed contact plate 12, and the other end of the drive coil 15 is integrally connected to the terminal plate 18. The upper end of the drive coil 15 is located below the position of the movable contact 13 when the movable contact 13 is farthest from the fixed contact 11. That is, the distance from the fixed contact 11 to the upper end of the drive coil 15 is
It is set smaller than the maximum opening distance of. Terminal board 18
Has a left end portion to the left of the fixed contact plate 12, and a terminal screw 19 is screwed to the left end portion to form the terminal 2. The fixed contact plate 12, the drive coil 15, the terminal plate 18, etc. are integrally formed to form a contact plate body 20.

The yoke 16 is a bridging piece that magnetically short-circuits between a pair of leg pieces 16a arranged on both sides of the movable contact 14 and the upper ends of both leg pieces 16a.
16b is continuously formed integrally with each other and has a U-shaped cross section with a downward opening, and the drive coil 15 is arranged in one notch 24 of the yoke 6. In addition, the upper lower surface of the other notch portion 25 of the yoke 16 is the high portion 18a of the terminal plate 18.
Adheres to the upper surface of. Here, the lower end surface of the leg piece 16a of the yoke 16 is in close contact with the upper surface of the lower portion 18b of the terminal plate 18. One end surface of the yoke 1 is a plate-shaped partition plate made of a molded product.
21 is provided in close contact, and the other side of the yoke 16, that is, the terminal 2 side (power supply side), is provided in close contact with a flat plate-shaped exhaust plate 26 made of a molded product. As shown in FIGS. 2 and 4, the partition plate 21 has a slit through which the movable contact 14 is inserted.
21 is provided, and the side piece 21a of the partition plate 21 is inserted into the groove 23 formed in the housing 1. Similarly, the exhaust plate 26 has a groove 2 formed with the side piece 26a formed in the housing 1.
It is inserted in 8 and fixed. The exhaust plate 26 has a plurality of exhaust holes 27 for exhausting the arc gas. The yoke 16, the partition plate 21, and the exhaust plate 26 form an arc extinguishing chamber 3 as shown in FIG. 3, and also serve as an exhaust passage for guiding an arc extinguished in the arc extinguishing chamber 3 to an exhaust hole 27. . Therefore, in the arc-extinguishing chamber 3 composed of the yoke 16, the partition plate 21, and the exhaust plate 26, the contact portion is provided over the entire length of the moving range of the movable contactor 14.
It covers 10. The operation will be described after the other embodiments.

FIG. 5 shows another embodiment, in which a box-shaped insulating cap 17 made of an insulating material is arranged on the lower surface of the yoke 16, and the partition plate 21 and the exhaust plate 26 are integrally molded to form an insulating cap 17.
Is formed. That is, the contact portion 10 is covered with the U-shaped central portion 29 of the integrally molded box-shaped insulating cap 17, and the yoke 16 is arranged on the outer peripheral surface of the central piece 29. In addition, a flange 30 protruding laterally is formed on the periphery of the insulating cap 17, and a yoke is provided on the outer periphery of the insulating cap 17.
When the flange 16 is fitted, the flange 30 positions the insulating cap 17. In this embodiment, since the partition plate 21 and the exhaust plate 26 are integrally molded to form the insulating cap 17, the partition plate is the same as in the previous embodiment.
It is not necessary to dispose 21 and the exhaust plate 26, respectively, and it is sufficient to dispose them as the insulating cap 17 in the housing 1 or the like. Further, when disposing the yoke 16, it is sufficient to simply fit them to the insulating cap 17, and they are easily assembled. Is something that can be done.
As the insulating material forming the insulating cap 17, an insulating material that generates a pyrolytic gas by arc heat is used. That is, the arc is cooled by this pyrolyzed gas, and the arc is quickly extinguished. As such an insulating material, polymetal pentene resin, polyethylmethacrylate resin,
There are polybutylene resins and the like, and it is known that these resins easily generate gas as a thermal decomposition product, particularly hydrogen gas, during a thermal decomposition reaction.

(Operation) The operation will be described below with reference to FIGS. 6 and 7. still,
6 and 7 show that the insulating cap 17 is used. Fixed contact plate when contact 10 is closed
12 and the movable contact 14 are arranged substantially parallel to each other, and currents flowing in opposite directions flow through the fixed contact plate 12 and the movable contact 14. Here, a large current such as a short-circuit current
When a magnetic field is generated by a current flowing through the fixed contact plate 12 and the movable contact 14 when passing through the contact point 10, a strong repulsive force momentarily acts between the fixed contact plate 12 and the movable contact 14 to cause the contact portion 10 to move. Opens. Further, a magnetic field is generated around the drive coil 15 by the current flowing through the drive coil 15, and this magnetic flux φ ₁ passes near the central axes of both coils 15 in the portion sandwiched by the both drive coils 15, and other than that. In the part, the yoke 16 is used as a magnetic path. Therefore, when a large current passes, the movable contact
The movable contact 14 is biased upward by an electromagnetic force, which is an interaction between the current flowing through 14 and the magnetic field around the drive coil 15. That is, the magnetic force between the movable contact 14 and the fixed contact plate 12 and the electromagnetic force between the movable contact 14 and the drive coil 15 cause the movable contact 14 to instantaneously move upward. After that, the trip device or the like operates to mechanically separate the movable contact 1 from the fixed terminal plate 12. With such opening of the contact portion 10, an arc is generated between the fixed contact 11 and the movable contact 13. As described above, the magnetic field is generated around the drive coil 15, and the yoke 16 is arranged so as to surround the drive coil 15. Therefore, the magnetic flux φ ₁ around the drive coil 15 is shown in FIG. As shown in b),
It will pass through the inside of the yoke 16. The arc 9 receives the electromagnetic force due to the interaction between the magnetic field and the arc 9, and the arc 9 is shown in FIG. 6 (a).
It is urged toward the center left. In this way arc 9
When the central part of the arc swells, FIG.
Since the arc 9 runs in the left-right direction in the inside, as shown in FIG. 7, the magnetic field generated around the arc 9 is similar to the magnetic field generated around the movable contact 14 and the central portion of the arc 9 is shown in FIG. It urges to the left in (a) and simultaneously urges the upper part of the arc 9 upward. In this way, the central portion of the arc 9 is biased to the left, and the upper portion of the arc 9 is biased upward to stretch the central portion of the arc 9 up and down, so that the arc 9 is sufficiently stretched and high. The arc voltage is obtained and the arc current is limited. Also the drive coil
The magnetic flux φ ₁ generated by 15 passes through the inside of the yoke 16 at the outer peripheral portion of the drive coil 15 as shown in FIG. 6 (b) and FIG. 7 (b). Even if the movable contact 14 is located above the drive coil 15 in the process, the magnetic flux φ ₁ generated around the drive coil 15 and the movable contact 14
The magnetic flux φ generated around the coil does not reverse direction, and the magnetic flux φ ₁ around the drive coil 15 does not hinder the movement of the movable contactor 14. That is, the movable contact 14 rapidly separates the movable contact 13 from the fixed contact 11 to rapidly increase the arc voltage and suppress the arc current. And
The partition plate 21 prevents the arc 9 from being pushed back to the mechanically movable part by the high-pressure arc gas generated when the contact portion 10 is opened, and the arc gas is exhausted through the exhaust hole 27 of the exhaust plate 26 that constitutes the arc extinguishing chamber 3. It can be effectively discharged via.

In addition, the insulation cap is generated by the arc heat when the arc 9 is generated.
Pyrolysis gas is generated from the resin that forms 17,
The arc 9 is cooled by this pyrolysis gas, a high arc voltage is obtained, and the extinction of the arc 9 can be further accelerated.

[Advantages of the Invention] As described above, the present invention is a circuit breaker for wiring having an arc extinguishing chamber for extinguishing an arc generated when a fixed contact and a movable contact are separated from each other, and a contact plate provided with a fixed contact. Body and
A movable contact, which is provided with a movable contact that forms a contact with the fixed contact, is formed in a long shape in a direction substantially orthogonal to the opening / closing direction of the contact, and is energized in the longitudinal direction thereof, and a fixed contact plate sandwiching the fixed contact. A pair of drive coils, which are arranged on both sides of the contact part and apply a magnetic force to the movable contact in a direction in which the contact part opens when the contact part is closed, and a magnetic path of a magnetic flux generated by the drive coil, which is made of a magnetic material. And a U-shape having a pair of legs and a bridging piece magnetically short-circuiting between the upper ends of the legs, the lower ends of which are substantially in close contact with the upper surface of the contact plate body and are arranged on both sides of the contact part. A partition plate that is inserted through the yoke of the mold and the movable contactor to prevent the arc from being pushed back, and is closely attached to one end side of the yoke, and is provided to closely discharge the arc gas to the other end side of the yoke. Equipped with an exhaust plate that is installed around the movable contactor. The arc-extinguishing chamber that extinguishes the arc by energizing the arc by the electromagnetic force generated between the magnetic field and the arc generated when the contact is opened is formed by the yoke, the partition plate and the exhaust plate. The magnetic field generated around the movable contactor, and the electromagnetic force that is the interaction between the magnetic field generated around the arc itself and the arc makes it possible to urge the arc and stretch the arc sufficiently long, Since a sufficiently high arc voltage is obtained and the arc current is suppressed, the arc can be extinguished, and the yoke that constitutes the arc extinguishing chamber that extinguishes this arc, the partition plate and the exhaust plate also serve as the exhaust passage, It is possible to prevent the arc gas pressure from being directly applied to the surrounding housing, etc. Therefore, the arc gas pressure applied to the housing etc. will be reduced,
Since the thickness of the molded product can be made thin, and the yoke serving as the exhaust passage is made of a magnetic material, it has the effect of providing strength to the arc gas pressure applied to the exhaust passage. is there.

[Brief description of drawings]

1 is an exploded perspective view of an essential part of an embodiment of the present invention, FIG. 2 is a perspective view of a partition plate of the same, FIG. 3 is a partially cutaway side view of the same circuit breaker, and FIG. FIG. 5 is an exploded perspective view of an essential part showing another embodiment of the same, and FIGS. 6 and 7 are operation explanatory views of the same. 3 is an arc extinguishing chamber, 10 is a contact portion, 11 is a fixed contact, 13 is a movable contact, 14 is a movable contactor, 15 is a drive coil, 16 is a yoke, 20
Is a contact plate body, 21 is a partition plate, and 26 is an exhaust plate.

Claims (1)

[Scope of utility model registration request] 1. A wiring circuit breaker having an arc extinguishing chamber for extinguishing an arc generated when a fixed contact and a movable contact are separated from each other, and a contact plate body provided with the fixed contact, and a contact portion together with the fixed contact. And a movable contact that is formed in a long shape in a direction substantially orthogonal to the opening and closing direction of the contact portion and that is energized in the longitudinal direction, and is arranged on both sides of the fixed contact plate with the fixed contact interposed therebetween. In the closed state of the contact part, a pair of drive coils act on the movable contact to cause electromagnetic force in the direction of opening the contact part, and a magnetic path of the magnetic flux generated by the drive coil and made of a magnetic material A U-shaped yoke having a pair of leg pieces arranged on both sides, whose lower ends are substantially in close contact with the upper surface of the contact plate body, and a bridging piece that magnetically short-circuits the upper ends of the leg pieces, Insert the contactor and prevent the arc from being pushed back. The yoke includes a partition plate closely attached to one end side of the yoke, and an exhaust plate exhausted from the arc gas and closely attached to the other end side of the yoke. A circuit breaker for wiring, characterized in that an arc extinguishing chamber for extinguishing the arc by being urged by the electromagnetic force generated between the arc and the arc generated when the electrode is opened is formed by a yoke, a partition plate and an exhaust plate. Arc-extinguishing chamber structure.