JP3394600B2 - Circuit breaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of arc extinguishing performance of a circuit breaker, and more particularly, a circuit breaker in which a pair of opening and closing contacts are both movable.

[0002]

2. Description of the Related Art A circuit breaker that cuts off a circuit current when a contact breaks open causes the amount of arc generated between the broken contacts to increase as the circuit voltage increases and the breaking current increases. It becomes large and it becomes difficult to cut off. For this reason, the breaking performance can be improved by extinguishing this arc as soon as possible.

There is a circuit breaker in which both contacting and separating contacts move at the time of opening and closing, and a structure of an example of such a conventional circuit breaker is shown in FIGS. There is.

The circuit breaker shown in FIG. 4 is of a draw-out type, and shows a closed state in which the main body of the breaker is at the connecting position and the contacts are in contact with each other.

Such a conventional draw-out type circuit breaker comprises a mounting frame 1 and a circuit breaker main body 2, and the mounting frame 1
Is fixed to a structure not shown, and the circuit breaker body 2
Is provided so as to be movable left and right along a guide rail (not shown) provided on the mounting frame 1. Also, the mounting frame 1
Is composed of a molded insulating material 3 and a pair of upper and lower external wire connecting terminals 4 fixed to the molded insulating material 3.
Are connected to a power source and a load device, respectively.

Further, the circuit breaker body 2 has a contact device section 100.
And an opening / closing operation mechanism portion 6 whose details are not shown. The contact device section 100 includes a first contactor 8 having first contacts 7 fixed to the upper and lower ends and a pair of upper and lower second contactor units 101. The contactor unit 100 is formed of molded insulators 10 and 11 and has an exhaust port vertically. It is housed in an insulating case provided with 12. In addition, the second contactor unit 101
Are vertically symmetrically attached to the molded insulator 11 with screws (not shown). An arc extinguishing device 13 configured by a plurality of magnetic plates supported by an insulator is housed between the contact device portion 100 and the exhaust port 12.

The first contactor 8 is attached to one end of an operating rod 15 made of a molded insulating material, and the operating rod 15
The other end is connected to a part of an appropriate opening / closing operation mechanism section 6, and when the opening / closing operation mechanism section 6 is operated, the operating rod 15
Are configured to move left or right.

The second contactor unit 101 includes a molded insulator box 102, a second contactor 103, a first contact pressure spring 104,
The second contact pressure spring 105 and the arc runner 106 made of a conductive material are mounted. The second contactor 103 of the second contactor unit 101 is limited by the shaft 107 that penetrates the elongated hole 103a formed in the upper part and the side wall of the molded insulating box body 102, and the inner wall of the molded insulating box 102. Within the range, the first contact pressure spring 104 and the second contact pressure spring 105 are loosely fitted and held. Furthermore, the second
A lead-out contact portion 103b is formed at one end of the contactor 103 as a portion that comes into contact with and separates from the external wire connection terminal 4, and a second contact 108 is fixed to the other end so as to face the first contact 7. The upper portion of the second contactor 103 has the first contact pressure spring 10
The pull-out contact portion 103 b is biased by the acting force of 4 so as to come into contact with the outside wire connection terminal 4. Further, the lower portion of the second contactor 103 is biased by the acting force of the second contact pressure spring 105 so that the second contact point 108 contacts the first contact point 7. Further, the arc runner 106 has the second contact 10
8 is provided on the arc extinguishing device 13 side, and its bent end faces the protrusion 103 c formed on the second contact 103.

The circuit path of the circuit current of the conventional draw-out type circuit breaker thus constructed is, therefore, the outer line connecting terminal 4 on the upper side → the second contact 103 → the second contact 108 → the first contact 7 → First contact 8 → lower first contact 7 → second contact 108
-> 2nd contactor 103-> It becomes like the external wire connection terminal 4 of the lower side.

In an electric circuit to which such a conventional draw-out type circuit breaker is connected, when a short circuit accident occurs and a large short circuit current flows, an unillustrated overcurrent trip device operates and automatically operates. The opening / closing operation mechanism unit 6 operates and the first contactor 8 attached to the operation rod 15 moves to the left. At this time, the lower portion of the second contactor 103 moves to the left due to the acting force of the second contact pressure spring 105, and the projection 103c comes into contact with the arc runner 106 and stops. Further, when the first contactor 8 moves to the left, the first contact 7 moves the second contact 108.
And an arc is generated between them. Such a state is shown in FIG.

Due to the action of the magnetic field generated by the arc itself, the arc is attracted toward the arc extinguishing device 13, and one end of the arc moves from the second contact 108 to the arc runner 106 made of a conductive material, and the arc runner 106. The arc is maintained between the first contact 7 and the first contactor 8. The current path at this time will be described with respect to the upper second contactor unit 101. External line connection terminal 4 → second contactor 103 → projection 103c → arc runner 106 → arc extinguishing device 13 → first contact 7 → first contactor It becomes like 8. This arc is cooled by the arc extinguishing device 13, and the further operation of the opening / closing mechanism 6 causes the first contactor 8 to move to the left to increase the insulation distance between the first contact 7 and the arc runner 106, thereby increasing the first contact. It will disappear by the time the child reaches the open circuit completion position.

[0012]

In the conventional circuit breaker configured as described above, when a large current such as a short-circuit current is cut off, the generated arc is attracted toward the arc extinguishing device. Since there is only the action of the magnetic field generated in the arc current itself, the attraction is not sufficient to interrupt a larger current, and therefore there is a problem that the breaking capacity cannot be set large.

Therefore, an object of the present invention is to provide a circuit breaker capable of interrupting a large short circuit current by a simple method.

[0014]

In order to achieve the above object, according to the present invention, a circuit breaker includes a first contactor having an opening / closing contact portion, and an opening / closing operation for operating the first contactor. Mechanism, a second contactor having an opening / closing contact portion capable of coming into contact with and separating from the first contactor, an arc extinguishing device including a magnetic body, and one end provided in the vicinity of the second contactor extending in the direction of the arc extinguishing device to become comprises a runner, opening and closing the contact portion of the second contact is biased by a spring force in the direction of the first contactor
Contact with the open / close contact portion of the first contactor in the closed state
However , the arc runner further has a portion facing the first contactor on the side opposite to the arc extinguishing device side with respect to the opening / closing contact portion of the second contactor, and the second runner is provided with the second contactor during the opening operation .
The contactor comes into contact with the other end of the arc runner to stop its displacement, and the opening / closing contact portion of the first contactor and the second contactor are contacted.
When the open / close contact part of the
The first contactor to the portion of the battery that faces the first contactor.
It is characterized in that a current flows in the opposite direction to the flowing current .

Further, in the circuit breaker of the present invention,
The first contactor has opening and closing contact portions electrically arranged in series at both ends, and the second contactor, the arc runner, and the arc extinguishing device correspond to respective opening and closing contact portions of the first contactor. It is characterized in that an insulator is provided in the central portion of the first contactor for isolating the open / close contact portion formed by the pair of first and second contactors from each other.

[0016]

In the circuit breaker of the present invention, when a large current such as a short-circuit current is cut off, the first contactor moves in the direction of separating from the second contactor when operated by the opening / closing mechanism. The second contact, which is biased toward the first contactor, comes into contact with the other end of the arc runner and stops. Further, when the first contactor moves, the first and second contactors are separated and an arc is generated between the two contactors. Since this arc is attracted toward the arc extinguishing device and one of the arc ends moves to the arc runner, the short-circuit current flowing through the arc flows from the second contactor to the one end direction of the arc runner via the other end of the arc runner. As a result, the first contact of the arc runner
The electric current in the opposite direction to the current flowing through the first contactor is applied to the facing portion
The current flows in the opposite direction, and the magnetic force generated by the current flowing in the opposite direction acts so as to move the arc toward the arc extinguishing device, so that the arc can be extinguished early.

The circuit breaker of the present invention according to claim 2 is
In order to isolate the two-point breaker arranged in series, that is, the two-point switching contact parts with an insulator such as an insulation barrier, the high-temperature and high-pressure gases generated at both ends when short-circuit current is cut off are mixed together to form an arc. Preventing connection.

Other objects, features and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings.

[0019]

1 to 3 of the drawings show an embodiment of the circuit breaker of the present invention, which will be described in detail below with reference to the drawings. It should be noted that in these drawings, parts equivalent to those of the conventional technique are denoted by the same reference numerals, and part of the description of the overlapping parts may be omitted.

FIG. 1 is a diagram showing a closed state in which the circuit breaker of the present invention is in the connection position. As shown in the figure, the circuit breaker of the present invention comprises a mounting frame 1 and a circuit breaker main body 2. The circuit breaker main body 2 includes a contact device section 5 and an opening / closing operation mechanism section 6 whose details are not shown. It consists of The contact device section 5 has a first opening / closing contact section at both upper and lower ends.
In an insulating case including a first contactor 8 to which a contact 7 is fixed and a pair of upper and lower second contactor units 9, formed of molded insulators 10 and 11, and having exhaust ports 12 provided on the upper and lower sides, respectively. It is stored in. The pair of upper and lower second contactor units 9 are vertically symmetrically attached to the molded insulator 11 by screws (not shown). Further, an arc extinguishing device 13 composed of a plurality of magnetic plates supported by an insulator is housed between the contactor device portion 5 and the exhaust port 12.

The first contactor 8 of the contact device section 5 is provided with an insulating material such as an insulating barrier 14 so as to isolate the upper and lower contactor device sections 5 from each other regardless of whether the circuit breaker is open or closed. Installed. The first contactor 8 is attached to one end of an operation rod 15 made of a molded insulator, and the other end of the operation rod 15 is connected to a part of the opening / closing operation mechanism section 6 to open / close the opening / closing operation mechanism section 6. When is operated, the operating rod 15 is configured to move to the left or right.

FIG. 2 is an enlarged view of a part of the pair of upper and lower second contactor units 9 shown in FIG. 1, showing the upper second contactor unit 9 in FIG. 1, but showing the lower second contactor unit 9. 9
Needless to say, they also have the same symmetrical structure.
The second contactor unit 9 shown in FIG. 2 has a second contactor 24 housed in a box 23, as shown in the figure. The box body 23 of the second contactor unit 9 as described above is
A molded insulator base 19 having side walls and provided with openings for the external wire connection terminals 4, a magnetic plate 20 attached to the molded insulator base 19, and a non-magnetic plate 21 attached to the molded insulator base 19. And an arc runner 22 made of a conductive material and attached to the magnetic plate 20 and the non-magnetic plate 21 and provided with an opening for a second contact 28 which is an opening / closing contact portion of the second contact 24. The box-shaped body 23 includes a second contact 24 and a first contact 24.
The contact pressure spring 25 and the second contact pressure spring 26 are loosely fitted and housed in a state of being pressed together.

The second contactor 24 has a first contact pressure spring 25 which is bridged between the upper left end of the second contactor 24 and the magnetic plate 20.
The projection 24a formed at the upper right end of the second contact 24 is fitted into and contacted with the recess of the external wire connection terminal 4 by the action force of the above, and is at the connection position. Although not shown, when the circuit breaker main body 2 moves to the left, the upper portion of the second contact 24 is moved leftward by the acting force of the first contact pressure spring 25, and the stopper pin 27 is moved. When it comes into contact with
When a and the external line connection terminal 4 are separated, and the circuit breaker main body 2 is further moved so that the separation distance becomes a predetermined value, the circuit breaker position is established.

A second contact pressure spring 26 is provided between the lower portion of the second contact 24 and the molded insulator base 19, and the lower portion of the second contact 24 is biased to the left. There is. Furthermore, a second contact 28 is fixed to the lower left end of the second contact 24 at a position facing the first contact 7 of the first contact 8, and the second contact pressure spring 26 applies a second contact 28 to the first contact 7. 1
The contact 7 and the second contact 28 are in contact with each other.

The lower end of the arc runner 22 has a second contact 28.
Has a portion A that extends downward and faces the first contactor 8, and the end portion 22a of this extended portion is bent and fixedly connected to the non-magnetic plate 21. The end portion 22a faces the protrusion 24b formed at the lower end of the second contact 24 with a gap.

When the circuit breaker of the present invention thus constructed is connected to an electric circuit, when a short-circuit accident occurs in such an electric circuit, for example, the short-circuit current is as shown in FIG.
The outer wire connection terminal 4 on the upper side → the second contact 24 on the upper side
→ Upper second contact 28 → Upper first contact 7 → First contact 8 → Lower first contact 7 → Lower second contact 28 → Lower second contact 24 → Lower outer wire While flowing through the path of the connection terminal 4 and the like, an unillustrated overcurrent tripping device operates to open / close the opening / closing operation mechanism unit 6, and the operation rod 15 and the first contactor 8 move to the left.

At this time, for example, the upper second contact 24
Is moved to the left by the acting force of the second contact pressure spring 26, and the protrusion 24b of the second contact 24 comes into contact with the end 22a of the arc runner 22. Therefore, when the movement of the second contact 24 is stopped, the first contact 7 is separated from the second contact 28, and an arc is generated between the first contact 7 and the second contact 28. This arc is attracted toward the arc extinguishing device 13 by the magnetic field generated by the arc current itself and the action of the arc extinguishing device 13, and one end of the arc moves from the second contact 28 to the arc runner 22. At this time, the protrusion 2 of the second contact 24
4b and the end portion 22a of the arc runner 22 are in contact with each other, the current flow path will be described, for example, with respect to the upper second contactor unit 9.
Upper second contact 24 → Protrusion 2 of upper second contact 24
4b → the end portion 22a of the upper arc runner 22 → the upper arc runner 22 → the upper arc extinguishing device 13 → the upper first contact 7 → the first contact 8 and so on (FIG. 3).

As shown in FIG. 3, such a current is
Since the contactor 8 and the opposing portion A of the arc runner 22 are in opposite directions to each other, the arc is further subjected to electromagnetic force in a direction opposite to the opposing portion A, that is, in the direction of the arc extinguishing device 13. As a result, the arc moves toward the arc extinguishing device 13 at an early stage to increase the arc length, thus increasing the arc resistance and prematurely cooling the arc by the arc extinguishing device 13. The arc is extinguished earlier until the child 8 moves to the open circuit completion position, and the breaking performance is improved. Therefore, since a circuit breaker with good breaking performance can set a higher breaking capacity, it has the same size as that of the prior art, and the performance of the circuit breaker without any expensive parts or major changes. The performance of can be improved.

Further, when a large short-circuit current is cut off, the high-temperature and high-pressure conductive gas which is instantaneously generated in the upper and lower contactor device parts 5 is mixed and an arc is directly connected between the upper and lower second contactors 24. It may be impossible to block. In order to prevent this, the insulating barrier 14 capable of withstanding the high temperature and high pressure of such gas is provided with the first contactor 8 as shown in FIG.
Since it is provided almost at the center, the upper and lower contactor device portions 5 can be always isolated from before the occurrence of the arc to the completion of the interruption, so that a larger short-circuit current can be interrupted.

The above-described embodiment of the circuit breaker of the present invention is an example in which two points are cut off by the first contactor 8 having contacts at both ends and moving horizontally, but the first contactor which is a movable contactor It can also be applied to a one-point breaking type circuit breaker in which one end is held by a hinge or a pivot, a contact is provided at the other end, and only one second contactor unit 9 is provided corresponding to this contact.

[0031]

According to the circuit breaker of the present invention configured as described above, it is possible to increase the driving force for attracting the arc generated when the short-circuit current is interrupted to the arc-extinguishing device by switching the circuit during the breaking operation. The second contactor is brought into contact with the arc runner on the side opposite to the arc extinguishing device with respect to the contact portion to form the first contactor of the arc runner.
The electric current in the opposite direction to the current flowing through the first contactor is applied to the facing portion.
This can be achieved by simply passing a current, and as a result, the breaking capacity of the circuit breaker can be set large . Further, in the circuit breaker of the two-point breaking system, the breaking capacity can be set to a larger value simply by adding an insulator as an insulating barrier to the first contactor.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of a circuit breaker configured according to the present invention in a closed state.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a side sectional view of the embodiment of the circuit breaker of the present invention shown in FIG.

FIG. 4 is a side sectional view of a circuit breaker according to the related art in a closed state.

5 is a side sectional view of the prior art circuit breaker of FIG. 4 in the middle of breaking.

[Explanation of symbols]

1 mounting frame 2 Circuit breaker body 3 Insulation molding 4 External connection terminal 5 Contact device section 6 Opening / closing operation mechanism 7 first contact 8 First contact 9 Second contactor unit 10 Molded insulation 11 Molded insulation 12 exhaust port 13 Arc extinguishing device 14 Insulation barrier 19 Molded insulation base 20 magnetic plate 21 Non-magnetic plate 22 Arc Lanna 23 Box 24 Second contact 25 1st contact pressure spring 26 Second contact pressure spring 28 Second contact

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-86415 (JP, A) JP-A-58-169746 (JP, A) Actual development Shou- 60-123942 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H01H 71/00-83/22

Claims (2)

(57) [Claims] 1. A first contactor having an opening / closing contact part, an opening / closing operation mechanism for operating the first contactor, a second contactor having an opening / closing contact part capable of coming into contact with and separating from the first contactor, and a magnetic body. An arc-extinguishing device including an arc runner having one end extending in the direction of the arc-extinguishing device, the arc-runner being provided in the vicinity of the second contactor, and the opening / closing contact portion of the second contactor facing the first contactor. Is biased by the spring force into the first contact in the closed state.
Contact with the closing contact portion of probe, the arc runner further comprises a portion which faces the first contact on the opposite side of the arc extinguishing device side with respect to opening and closing the contact portion of the second contact, opening operation <br ), The second contactor comes into contact with the other end of the arc runner to stop the displacement , and the first contactor is opened and closed.
The contact portion and the opening / closing contact portion of the second contact are separated from each other.
When facing, it faces the first contactor of the arc runner.
A current flowing in the opposite direction to the current flowing through the first contactor
Circuit breaker characterized by flowing . 2. The first contactor has opening and closing contact portions electrically arranged in series at both ends thereof, and the second contactor, the arc runner and the arc extinguishing device open and close each of the first contactors. It is provided so as to correspond to the contact portion, and an insulator for isolating the opening / closing contact portion by the pair of the first and second contacts from each other is provided at the central portion of the first contactor. The circuit breaker according to claim 1.