JP4090968B2 - Circuit breaker - Google Patents

Description

According to the present invention, a fixed contact is provided at one end and the other end is connected to a circuit conductor on the power source side, and one end is disposed to face one end of the first fixed contact. A second fixed contact provided with a fixed contact similar to the above-mentioned fixed contact and having the other end connected to the load-side circuit conductor;
In a circuit breaker having a movable contact which is separated from and connected to the pair of fixed contacts and which opens and closes an electric circuit by the separation of the movable contact, particularly for extinguishing an arc generated when a large current is interrupted. The present invention relates to a circuit breaker having a pair of arc extinguishing chambers.

  In the conventional circuit breaker, one end is connected to the power supply side terminal and one end is connected to the load side terminal, and one end is connected to the load side terminal, and the other end has a fixed contact in the case. A fixed contact provided is provided, movable contacts are provided at both ends, and a movable contact that bridges or separates between the fixed contacts of the power source side and the load side fixed contact is provided. In addition, a known overcurrent tripping device is provided together with an opening / closing mechanism for opening / closing the electric circuit of each pole by bridging or separation of the movable contact. Further, an arc extinguishing chamber is provided for extinguishing the arc generated between the fixed contact and the movable contact. This arc extinguishing chamber is provided for each pole of both the power source side and load side fixed contactors. Each is arranged in the vicinity.

  When the current flowing through the circuit breaker configured as described above flows to the overcurrent trip device via the fixed contact on the power source side, the movable contact, and the fixed contact on the load side, this current becomes a large current. Then, the overcurrent tripping device is activated to trip the open / close mechanism, the movable contact is separated from the fixed contact, and the electric circuit is opened. At this time, an arc is generated between the fixed contact and the movable contact, and the arc is cooled and extinguished in the pair of arc extinguishing chambers. (For example, refer to Patent Document 1).

JP 2001-229800 A (FIG. 3)

  The conventional circuit breaker is configured as described above, and in the case of a multipole circuit breaker, the arc generation location is separated into two locations for each pole. I needed a room. Accordingly, since the space occupied by the arc-extinguishing chamber is large, there is a possibility that the storage of other functional parts in the case may be restricted, and it is necessary to install two arc-extinguishing chambers at predetermined positions for each pole. As a result, there are problems such as poor assembly of the circuit breaker.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a circuit breaker that facilitates the storage of functional components inside the circuit breaker and has good assemblability. It is.

In the circuit breaker according to the present invention, a fixed contact is provided at one end and the other end is connected to a circuit conductor on the power supply side, and one end faces one end of the first fixed contact. A fixed contact similar to the above-mentioned fixed contact and the other end of which is connected to the load-side circuit conductor, and movable contacts are provided at both ends opposite to the fixed contact. A movable contact that bridges the first fixed contact and the second fixed contact; and the movable contact coupled to the movable contact with the first fixed contact and the second fixed contact. An opening / closing mechanism for separating and contacting the contact; and an arc extinguishing chamber disposed near both ends of the movable contact for extinguishing arcs generated when the movable contact is separated from the fixed contact; The arc-extinguishing chamber includes a plurality of arc-extinguishing groups. A first grid group disposed in the vicinity of a fixed contact portion of the first fixed contact and a movable contact portion facing the fixed contact portion, and a fixed contact of the second fixed contact portion and holds integrally by a second grid unit and the extinguishing chamber side plate which is formed in a frame shape by bending the insulating sheet disposed in the vicinity of the movable contact portion opposite to the fixed contact portion, said first A cooling plate straddling both grid groups is arranged above the first grid group and the second grid group, and a convex portion formed on the peripheral surface of the cooling plate is formed in a locking hole formed in the arc extinguishing chamber side plate. It is inserted and fixed and held .

According to the present invention, the arc extinguishing chamber has a first grid group disposed in the vicinity of the first fixed contact, a second grid group disposed in the vicinity of the second fixed contact, The one grid group and the second grid group are integrally held by the arc extinguishing chamber side plate formed in a frame shape by bending the insulating sheet, and at the top of the first grid group and the second grid group. Since a cooling plate straddling both grid groups is arranged, and a convex portion formed on the peripheral surface of the cooling plate is fitted and held in a locking hole formed in the arc extinguishing chamber side plate , circuit interruption When storing the functional parts stored in the interior of the vessel, there are fewer restrictions related to the arc extinguishing chamber. Moreover, since it becomes the structure which installs one arc-extinguishing chamber for every pole, a circuit breaker with good assembly property can be obtained.

Embodiment 1 FIG.
1 is a sectional view showing a side surface of a circuit breaker 100 according to Embodiment 1 of the present invention, FIG. 2 is an external view of an arc extinguishing chamber constituting the circuit breaker of FIG. 1, (a) is a plan view, and (b) ) Is a side view, FIG. 3 is a plan view of an arc extinguishing grid constituting the arc extinguishing chamber of FIG. 2, FIG. 4 is a plan view of a cooling plate constituting the arc extinguishing chamber of FIG. 2, and FIG. It is a perspective view of the arc-extinguishing chamber side plate which comprises an arc chamber.

  In FIG. 1, in the case 1 of the circuit breaker 100, a first fixed contact 3 having a fixed contact 2 at one end and the other end connected to a circuit conductor 3 a on the power source side, and a first at a first end. The second fixed contact 5 is provided opposite to one end of the fixed contact 3 and provided with a fixed contact 4 similar to the fixed contact 2 and the other end connected to the load-side circuit conductor 5a. is there. In addition, movable contacts 6 and 7 are provided at both ends so as to face the fixed contacts 2 and 4, and a movable or bridged between the first fixed contact 3 and the second fixed contact 5 is provided. A contact 8 is provided. These configurations are provided for each pole in the case of a three-pole circuit breaker. An opening / closing mechanism 9 for bridging or separating between the first fixed contact 3 and the second fixed contact 5 is connected to the movable contact 8. The movable contact 8 is provided with a contact spring 12 that urges the movable contact 8 in the direction of separating from the first fixed contact 3 and the second fixed contact 5.

  The circuit breaker 100 is provided with an overcurrent detection unit 11 that operates when the overcurrent flows to operate the switching mechanism 9. However, the mechanism for connection to the switching mechanism 9 is irrelevant to the gist of the present invention. The illustration is omitted. The housing 1 is provided with an arc gas discharge port 1a for discharging an arc generated in the arc extinguishing chamber 10 (described later) to the outside. The arc gas discharge port 1a is illustrated as being provided on the power supply side, but may be provided on the load side as necessary.

  2 to 5, the arc extinguishing chamber 10 includes an arc extinguishing chamber side plate 13 formed in a C-shaped frame shape by bending an insulating sheet such as a fiber plate, and the arc extinguishing as shown in FIG. The room side plate 13 is close to the first grid group 14 and the second grid group 15 held symmetrically as viewed from the side, and the first grid group 14 and the second grid group 15, respectively. The first cooling plate 16 and the second cooling plate 17 made of a metal material are provided.

The first grid group 14 and the second grid group 15 are formed by stacking and supporting a plurality of arc extinguishing grids 18 and 19 at predetermined intervals, respectively. The convex portions 18a and 19a are fitted and held in the locking holes 13a of the arc-extinguishing chamber side plate 13, and similarly, the convex portions 16a and 17a of the first cooling plate 16 and the second cooling plate 17 are arc-extinguishing chambers. The arc extinguishing chamber 10 is configured by being fitted and held in the locking hole 13 b of the side plate 13.
The arc extinguishing chamber side plate 13 is provided with an arc gas discharge hole 13c for discharging the arc gas in the arc extinguishing chamber 10 to the outside of the arc extinguishing chamber 10.

  In the circuit breaker 100 configured as described above, a large current such as a short circuit current is supplied from the circuit conductor 3a on the power source side to the first fixed contact 3, the movable contact 8, the second fixed contact 5, and the load. When the current flows to the overcurrent detection unit 11 via the circuit conductor 5a on the side, the opening / closing mechanism 9 is operated by the action of the overcurrent detection unit 11, and the movable contact 8 is released against the contact spring 12 and fixed at this time. An arc is generated between the contacts 2 and 4 and the movable contacts 6 and 7.

  The arc generated between the fixed contacts 2, 4 and the movable contacts 6, 7 is stretched by the action of the first grid group 14 and the second grid group 15, and is quickly extinguished in the arc extinguishing chamber 10. The At this time, the arc gas generated in the arc-extinguishing chamber 10 is cooled by the first cooling plate 16 and the second cooling plate 17 and is then supplied to the outside of the circuit breaker 100 through the ventilation hole 13c and the arc gas discharge port 1a. Discharged.

  As described above, the circuit breaker according to Embodiment 1 of the present invention integrally holds the first grid group 14 on the power source side and the second grid group 15 on the load side by the arc extinguishing chamber side plate 13. Further, the strength of the arc extinguishing chamber 10 itself is increased and the space can be reduced, so that other functional components in the housing 1 can be easily accommodated. Further, since the arc extinguishing chamber side plate 13 is formed in a C-shaped frame shape by bending an insulating sheet such as a fiber plate, the first grid group 14 and the second grid group 15 are separately inserted and held. Can be done. Therefore, the assembly workability of the arc extinguishing chamber 10 is improved. Furthermore, since the first cooling plate 16 and the second cooling plate 17 are disposed, the arc gas cooling action is increased, and the arc extinguishing chamber 10 is unlikely to become high temperature. The durability of the contacts 6 and 7 is improved.

  In the above configuration, the arc extinguishing chamber side plate 13 is formed by bending an insulating sheet into a C-shaped frame, but the first grid group 14 and the second grid group 15 are integrated. As an alternative, the grid groups 14 and 15 may be sandwiched from both sides using two insulating sheets. In addition, since the grid groups 14 and 15 themselves perform the same operation as the cooling plate, the cooling plates 16 and 17 may be omitted depending on the configuration of the grid groups 14 and 15.

Embodiment 2. FIG.
6 is a sectional view showing a side surface of a circuit breaker 101 according to Embodiment 2 of the present invention, FIG. 7 is an external view of an arc extinguishing chamber constituting the circuit breaker of FIG. 6, (a) is a plan view, (b) ) Is a side view, and FIG. 8 is a plan view of a cooling plate constituting the arc extinguishing chamber of FIG.

  In FIG. 6, in the housing 1 of the circuit breaker 101, a fixed contact 2 is provided at one end, and the other end is connected to the circuit conductor 3a on the power source side, and one end is the first. The second fixed contact 5 is provided opposite to one end of the fixed contact 3 and provided with a fixed contact 4 similar to the fixed contact 2 and the other end connected to the load-side circuit conductor 5a. is there. In addition, movable contacts 6 and 7 are provided at both ends so as to face the fixed contacts 2 and 4, and a movable or bridged between the first fixed contact 3 and the second fixed contact 5 is provided. A contact 8 is provided. An opening / closing mechanism 9 for bridging or separating between the first fixed contact 3 and the second fixed contact 5 is connected to the movable contact 8. The movable contact 8 is provided with a contact spring 12 that urges the movable contact 8 in the direction of separating from the first fixed contact 3 and the second fixed contact 5. Furthermore, the circuit breaker 101 is provided with an overcurrent detection unit 11 that operates when the overcurrent flows to operate the switching mechanism 9. The casing 1 is provided with an arc gas discharge port 1a for discharging an arc generated in the arc extinguishing chamber 20 (described later) to the outside. Since these configurations are the same as those in the first embodiment, detailed description thereof is omitted.

  The arc extinguishing chamber 20 is seen from the side by the arc extinguishing chamber side plate 21 formed into a rectangular frame shape by bending an insulating sheet such as a fiber plate and the arc extinguishing chamber side plate 21 as shown in FIG. The first grid group 14 and the second grid group 15 held symmetrically, and the cooling plate 22 made of a metal material disposed in the vicinity of the first grid group 14 and the second grid group 15. It is comprised by. In this case, the cooling plate 22 is held with the convex portion 22 a being inserted into the locking hole 21 a of the arc extinguishing chamber side plate 21. The cooling plate 22 is formed integrally with the first grid group 14 and the second grid group 15. The configuration in which the first grid group 14 and the second grid group 15 are fitted and held in the locking holes 21b of the arc extinguishing chamber side plate 21 is the same as that in the first embodiment, and thus the description thereof is omitted. According to this configuration, since the integrally formed cooling plate 22 is disposed, the strength of the arc extinguishing chamber 20 itself is increased, and the arc gas cooling effect is increased, so that the high temperature in the arc extinguishing chamber 20 is increased. In addition to the durability of the fixed contacts 2 and 4 and the movable contacts 6 and 7, problems such as burning are also suppressed in the internal mechanism of the circuit breaker. The through hole 22 b provided in the central portion of the cooling plate 22 is a hole through which a connecting member for connecting the opening / closing mechanism 9 to the movable contact 8 is inserted.

Embodiment 3 FIG.
Next, regarding the arc extinguishing chamber 20 shown in FIG. 7, an embodiment different from the description of the second embodiment will be described. That is, in the first and second embodiments, the plurality of arc extinguishing grids 18 and 19 constituting the first grid group 14 and the second grid group 15 are for arc extinguishing having the same size. Has been made on the grid. On the other hand, in this embodiment, the size of the arc extinguishing grid 19 is smaller than the size of the arc extinguishing grid 18. When it is made smaller, the arc extinguishing action of the second grid group 15 constituted by the arc extinguishing grid 19 decreases, but this point is more than the current that performs the arc extinguishing action on the first grid group 14 side. This can be solved by reducing the current for performing the arc extinguishing action on the second grid group 15 side. That is, for example, the opening timing of the fixed contact 2 and the movable contact 6 on the first grid group 14 side is slightly smaller than the opening timing of the fixed contact 4 and the movable contact 7 on the second grid group 15 side. This is done by setting the operation of the movable contact 8 or the configuration of the first fixed contact 3 and the second fixed contact 5 so as to be faster. According to this setting, the short-circuit current to be opened is limited by the separation of the fixed contact 2 and the movable contact 6 on the first grid group 14 side, so that the fixed contact 4 on the second grid group 15 side and the movable contact 6 are movable. When the contact 7 is opened, the current becomes small. By this action, the size of the arc extinguishing grid 19 can be set smaller than the size of the arc extinguishing grid 18.

  According to this configuration, the load-side second grid group 15 is formed smaller than the power-source-side first grid group 14, so that the space for the arc-extinguishing chamber 20 itself is reduced and the casing 1. It is easy to store other functional parts. Note that, depending on the internal configuration of the circuit breaker, the first grid group 14 on the power supply side can be formed smaller than the second grid group 15 on the load side. Further, the arc extinguishing chamber side plate 21 has a C-shaped frame shape or a rectangular frame shape because of the relationship of the mechanism for connecting the opening / closing mechanism 9 to the movable contact 8 or the relationship of the discharge path of the arc gas. However, since it is not directly related to the gist of the present invention, a detailed description is omitted.

It is sectional drawing which shows the side surface of the circuit breaker in Embodiment 1 of this invention. It is an external view of the arc extinguishing chamber which comprises the circuit breaker of FIG. 1, (a) is a top view, (b) is a side view. It is a top view of the grid which comprises the arc-extinguishing chamber of FIG. It is a top view of the 1st cooling plate and 2nd cooling plate which comprise the arc-extinguishing chamber of FIG. It is a perspective view of the arc-extinguishing chamber side plate which comprises the arc-extinguishing chamber of FIG. It is sectional drawing which shows the side surface of the circuit breaker in Embodiment 2 of this invention. It is an external view of the arc-extinguishing chamber which comprises the circuit breaker of FIG. 6, (a) is a top view, (b) is a side front view. It is a top view of the cooling plate which comprises the arc-extinguishing chamber of FIG.

Explanation of symbols

2, 4 fixed contacts, 3 first fixed contact, 5 second fixed contact,
6, 7 movable contact, 8 movable contact, 9 opening / closing mechanism, 10, 20 arc extinguishing chamber,
13 arc extinguishing chamber side plate, 14 first grid group, 15 second grid group,
16 First cooling plate, 17 Second cooling plate, 18, 19 Arc extinguishing grid,
100, 101 Circuit breaker.

Claims (2)

A first fixed contact provided with a fixed contact at one end and the other end connected to a circuit conductor on the power source side, and one end disposed opposite to one end of the first fixed contact and the fixed contact; A second fixed contact provided with the same fixed contact and the other end connected to the load-side circuit conductor, and a movable contact provided opposite to the fixed contact at both ends, the first fixed contact and the above A movable contact that bridges the second fixed contact; and an opening and closing mechanism that is connected to the movable contact and separates the movable contact from the first fixed contact and the second fixed contact; In a circuit breaker provided with an arc extinguishing chamber disposed near both ends of the movable contact and extinguishing arcs generated when the movable contact is separated from the fixed contact. The arc chamber comprises a plurality of arc extinguishing grids, and the first fixed contact A fixed contact portion, a first grid group disposed in the vicinity of the movable contact portion facing the fixed contact portion, a fixed contact portion of the second fixed contact, and a movable contact portion facing the fixed contact portion. The second grid group disposed in the vicinity is integrally held by the arc extinguishing chamber side plate formed in a frame shape by bending the insulating sheet , and at the top of the first grid group and the second grid group. A cooling plate straddling both grid groups is disposed, and a convex portion formed on the peripheral surface of the cooling plate is fitted into a locking hole formed in the arc-extinguishing chamber side plate and fixedly held. Circuit breaker to do. The opening timing of the fixed contact of the first fixed contact and the movable contact facing the fixed contact is set to be earlier than the fixed contact of the second fixed contact and the movable contact facing the fixed contact. the circuit breaker according to claim 1 Symbol mounting, characterized in that the size of the second grid groups extinguishing grid were small remote by extinguishing grid of the first grid groups.

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