JPH1069846A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a circuit breaker with excellent current cutoff performance and great current capacity as being capable of closing itself with small operating force. SOLUTION: The second contractors 41-44 are biased toward the first contractor 8 by the second contact pressure spring in the condition that a circuit breaker is closed and the ends 41a-44a thereof are engaged with the circular engagement edge 12b of a non-magnetic plate 12. In arrangement, the second contact 51 of the second contactor 41 arranged at the center comes nearest to the first contact 6 of the first contactor 8, the second contacts 52 of the second contactors 42 adjacent thereto at both sides comes second-nearest thereto and the second contacts 54 of the second contactors 44 at both side ends goes farthest from the first contact 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a circuit breaker, and more particularly to a circuit breaker having a large current capacity.

[0002]

2. Description of the Related Art In a circuit breaker, especially a circuit breaker having a large current capacity, in order to suppress generation of Joule heat due to contact resistance, switching contacts are divided to increase the number of contact points, thereby reducing the contact resistance. Many have been reduced.

An example of such a conventional circuit breaker is disclosed in Japanese Patent Application Laid-Open No. H8-17322. FIG. 7 is a side sectional view of the circuit breaker in a closed state. This circuit breaker includes a drawer frame 1 and a circuit breaker main body 2, and the drawer frame 1 is provided with a pair of upper and lower outer line connection terminals 3. On the other hand, the circuit breaker main body 2 includes a pair of upper and lower second contacts 4 that are in contact with the external line connection terminal 3, a first contact 8 that moves in the horizontal direction by the opening / closing operation mechanism 7, and a pair of upper and lower arc extinguishing devices 9. Is provided. Each of the second contacts 4 is provided with a second contact 5, and both ends of the first contact 8 are provided with a pair of first contacts 6 that are in contact with both second contacts 5.

FIGS. 8 and 9 are side views of a main part for explaining a relationship between the first contact 8 and the second contact 4 in a contact state and an open state, respectively. FIG. FIG. 4 is a bottom view as viewed from below. The second contact 4 is divided into a plurality of parts as shown in FIG. 10, and the molded insulator base 10 and the magnetic plate 1 are arranged in parallel so as to face the first contact 8.
1. It is loosely housed in a casing surrounded by the non-magnetic plate 12 and the arc runner 13. Each of the second contacts 4 has a first contact pressure spring 14 at one end thereof and an external line connection terminal 3.
And a second contact pressure spring 15 at the other end.
Urged in the direction of the first contact 8.

As shown in FIGS. 9 and 10, when the second contact 5 and the first contact 6 are separated from each other, that is, when the circuit breaker is in an open state, as shown in FIGS. 8, the end 4a of the second contact 4 is engaged with the engaging edge 12a of the non-magnetic plate 12 by the urging force of the second contact pressure spring 15, while the circuit breaker is closed as shown in FIG. Is closed, the first contact 6 presses the second contact 5 rightward against the urging force of the second contact pressure spring 15, thereby engaging with the end 4 a of the second contact 4. The mating edges 12a are separated from each other.

In this conventional circuit breaker, FIG.
As shown in FIG. 5, since the non-magnetic plate 12 has a linear engaging edge 12a parallel to the first contact 6, when the circuit breaker is in an open state, the plurality of second contacts 4 are formed. Second
The contacts 5 have the same separation distance from each other with respect to the first contact 6.

FIG. 11 is a front view showing the arc extinguishing device 9 arranged on the upper side of the circuit breaker main body 2. The arc extinguishing device 9 is configured to hold an arc extinguishing plate 9b made of a plurality of magnetic steel plates whose lower sides are cut out in a substantially V shape between a pair of left and right insulating plates 9a. The first contact 6 and the second contact 5
It is attached so that a contact portion with the locating member is located. In some conventional circuit breakers, the fixed contact is a wide contact portion and the movable contact is divided into a plurality of contacts, contrary to the above.

[0008]

In such a conventional contact device of a circuit breaker, the first contact 6 and the second contact 5 are arranged in parallel with each other, so that the first contact 6 is closed in the closing operation. All the second contacts 5 divided into a plurality of pieces will come into contact at the same time. Accordingly, since the acting forces of the plurality of second contact pressure springs 15 urging the plurality of second contacts 5 respectively act on the opening / closing operation mechanism 7 via the first contacts 8 at the same time, the opening / closing operation mechanism 7 7 requires a large closing operation force and a strong mechanism.

In the opening operation, since a plurality of contact points of the first contact 6 and the second contact 5 are simultaneously opened, an arc is generated between the first contact 6 and the plurality of second contacts 5. There is a problem in that the arcs are dispersed and generated, so that the arc is hardly attracted toward the arc extinguishing device 9, and there is a problem in the arc extinguishing performance, and the current interrupting performance is suppressed.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a circuit breaker which can be closed with a small operating force and has excellent current interruption performance.

[0011]

In order to solve the above problems, a circuit breaker according to the present invention is provided with an arc extinguishing device having a plurality of arc extinguishing plates, and an arc extinguishing device arranged near the arc extinguishing device. First contacts having a planar contact surface to be formed, each having a contact surface facing the contact surface of the first contact, and each being loosely fitted and urged in the direction of the first contact. In the separated state of the second contact divided into a plurality of second contacts and the first contact and the plurality of second contacts, the plurality of second contacts are arranged in the first direction from the center to the both ends as the second contacts are arranged at both ends. Locking means having locking edges for locking the plurality of second contacts so that the separation distance between the one contact and the contact surface is sequentially increased.

With such a configuration, the first contact and the second contact
When the contacts come in contact with each other, the second contact located at the center contacts first, and then the second contacts on both sides come into contact,
Since the second contactors at both ends are sequentially contacted one after another, the load required at the time of closing operation increases stepwise, and the circuit can be closed with less operating force than when all the second contacts come into contact at the same time. In addition, at the time of the opening operation, since the separation starts from the second contacts at both ends and finally the second contact at the center is separated,
The arc is concentrated at the center and the arc extinguishing performance is improved.

Also, the plurality of second contacts can be arranged in a fan shape as a whole such that the distance between them increases as the contact surface approaches the contact surface side. In this way, the adjacent second
The gap between the contact surfaces near the contact surfaces of the contacts can be ensured, and a small molten metal of a metal that may be generated by a high-temperature arc when interrupting a large current may cause a bridge between the adjacent second contacts. Disappears. Further, at the time of closing, the second contact other than the central portion contacts the contact surface of the first contact at an angle, and after contact, separates from the locking edge and makes planar contact. Since the second contact is loosely fitted, the second contact is displaced from the initial contact position, so that even if an arc is generated at the moment of contact of the contact, the second contact comes into contact with a position different from a trace generating portion due to the arc. And the stability of the contact is maintained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below by way of examples. The circuit breaker according to the embodiment is the same as the conventional circuit breaker shown in FIGS. 7 to 11 except for the arrangement of the second contact and the shape of the engaging edge of the nonmagnetic plate. Therefore, the same portions are denoted by the same reference symbols, and detailed description will be omitted.

FIG. 1 is a bottom view of the relationship between the first contact 8 and the second contact 4 in the open state of the circuit breaker according to the embodiment viewed from below. FIG. The second contacts 41 to 44 divided into a plurality of end portions 41 a to 41 a to engage with the engagement edges 12 b of the nonmagnetic plate 12, respectively.
Second contacts 51 to 54 are formed at the end of the first contact 8 facing the first contact 6 and having the first contact 8. Here, the engaging edge 12 b of the nonmagnetic plate 12 is formed in an arc shape so as to protrude toward the first contact 8. The non-magnetic plate 12 and the engaging edge 12b constitute the locking means and the locking edge of the present invention, respectively.

Each of the second contacts 41 to 44 is urged in the direction of the first contact 8 by a second contact pressure spring 15, similarly to the conventional circuit breaker shown in FIG. For this reason,
As shown in FIG. 1, in the open state of the circuit breaker, the plurality of second contacts 41 to 44 are configured such that the second contact 51 of the second contact 41 arranged in the center is the first contact 8. First
The second contact 42 closest to the contact 6 and on both sides thereof
Of the second contact 52 next to the second contactor 44, so that the closer to the second contact 54 of the second contactor 44 on both side ends, the greater the separation distance from the first contact 6 and the second contact 52 as a whole 51
They are arranged in a fan shape such that the distance between them increases as they approach the ~ 54 side.

The closing operation of the circuit breaker of the present embodiment configured as described above will be described. When the first contact 8 is moved rightward, that is, in the direction of the second contacts 41 to 44 from the state shown in FIG. 1 by operating the opening / closing operation mechanism 7 shown in FIG. 6 is located at the center of the second
It comes into contact with the second contact point 51 of the contact 41 in a planar manner. When the first contact 8 is further moved rightward, the second contact 41
End 41a is disengaged from the engaging edge 12b of the non-magnetic plate 12, and the first contact 6 comes into contact with one corner of the second contact 52 of the second contact 42 as shown in FIGS. At this time, as shown in FIG.
a is still engaged with the engagement edge 12b. When the first contact 8 further moves, as shown in FIG.
The entire surface of the second contact 52 contacts the first contact 6, and the end 42a of the second contact 42 is separated from the engagement edge 12b as shown in FIG. At this time, since the second contact 42 is loosely fitted, the end 4 of the second contact 42 is actuated by the action of the contact pressure spring.
2b moves in the direction of the end 43b of the second contact 43 and makes contact therewith. After the contact, the end provided with the second contact 52 slides toward the second contact 51. That is, the second contactor 42 sways laterally and deviates from the initial contact position. Similarly, the second contact 53 of the second contact 43 and the second contact 53 of the second contact 44
The contact 54 comes into contact with the first contact 6 to complete the closing operation.

The first contact 6 of the first contact 8 sequentially comes into contact with the second contacts 51 to 54 thus divided with a time lag against the urging force acting on each of the second contacts 51 to 54. , The circuit can be closed with a small operation force. Furthermore, since the small initial arc is generated at the moment of contact due to the difference between the initial contact position of the second contact points 51 to 54 and the contact position at the time of contact completion, a trace generating portion due to the arc is formed at the time of contact completion. Since contact is made at different portions, a good contact state can be ensured, and an improvement in current carrying capacity can be expected.

Next, the opening operation of the circuit breaker of this embodiment will be described. From the state where the first contact 6 of the first contact 8 and all the second contacts 51 to 54 of the second contacts 41 to 44 are in contact with each other, the opening and closing operation mechanism 7 is operated to open the circuit. When the contact 6 and the second contacts 51 to 54 are separated from each other, the second contacts 51 to 5 of the plurality of divided second contacts 41 to 44 are separated.
4, the second contact 51 located at the central portion is closer to the first contact 6.
Due to the small separation distance from the center, the generated arc concentrates on the central portion. Therefore, the arc is easily attracted to the arc-extinguishing plate 9b of the arc-extinguishing device 9. In addition, since the plurality of divided second contacts 41 to 44 are generally arranged in a substantially sector shape in an open state, a gap between adjacent second contacts is large, and a small metal flake is generated by the arc. However, the metal flakes do not adhere to both of the adjacent second contacts, so that the division of each of the second contacts is maintained, and the desired performance can be maintained.

In the above-described embodiment, the engaging edge 12b is formed in an arc shape. However, the engaging edge 12b is bent so as to be closest to the first contact point 6, that is, in a "C" shape. A mating edge can also be formed, and a similar effect is achieved.

[0021]

As described above, according to the present invention,
A circuit breaker that can be closed with a small operating force, has excellent current interrupting performance, and has a large current carrying capacity can be realized.

[Brief description of the drawings]

FIG. 1 is a bottom view showing a contact portion in an open state of a circuit breaker according to an embodiment of the present invention.

FIG. 2 is a bottom view showing a contact portion of the circuit breaker of FIG. 1 in a closing process.

FIG. 3 is an enlarged view of a portion A of FIG. 2;

FIG. 4 is an enlarged view of a part B of FIG. 2;

FIG. 5 is an enlarged view of a portion A in a state where a closing process is further advanced.

FIG. 6 is an enlarged view of a portion B in a state where a closing process has further progressed.

FIG. 7 is a side sectional view showing a conventional circuit breaker.

8 is a sectional view of a main part showing a contact portion of the circuit breaker of FIG. 7 in a closed state.

9 is a cross-sectional view of a main part showing a contact portion of the circuit breaker of FIG. 7 in an open circuit state.

FIG. 10 is a bottom view showing a contact portion of the circuit breaker of FIG. 7 in an open circuit state.

FIG. 11 is a front view showing the arc extinguishing device of the circuit breaker of FIG. 7;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 drawer frame 2 breaker body 3 external line connection terminal 41-44 second contact 41 a-44 a end 42 b, 43 b end 51-54 second contact 6 first contact 7 opening / closing operation mechanism 8 first contact 9 Arc device 12 Non-magnetic plate 12b Engagement edge 14 First contact pressure spring 15 Second contact spring

Claims (2)

[Claims] 1. An arc extinguishing device having a plurality of arc extinguishing plates, a first contact having a planar contact surface disposed close to the arc extinguishing device, each of which is in contact with the first contact. A plurality of second contacts having a contact surface facing the surface and each being loosely fitted and urged in the direction of the first contact, the first contact and the plurality of In the separated state from the second contact, the plurality of second contacts are arranged such that the distance from the contact surface of the first contact to the contact surface is gradually increased as the plurality of second contacts are arranged at both ends from the center. A locking means having a locking edge for locking the plurality of second contacts. 2. The circuit breaker according to claim 1, wherein the plurality of second contacts are arranged in a fan shape as a whole such that a distance between the second contacts increases toward the contact surface side. .