JP2009117210A - Circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit breaker capable of providing sharp electromagnetic repulsion and high arc-extinguishing performance of a movable contact, and improving contact failure of a contact and input failure of a handle. <P>SOLUTION: The movable contact is formed of a first movable contact on a movable contact part side and a second movable contact on a shaft support part side from an intermediate point of the shaft support part and the movable contact part. The first movable contact and the second movable contact are connected by a rotating shaft so that the first movable contact can bend and rotate in an open direction of the movable contact by electromagnetic repulsion force with respect to the second movable contact. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a circuit breaker such as a circuit breaker for wiring or a circuit breaker having a movable contact that opens a contact using an electromagnetic repulsive force when a short-circuit current or the like flows. It is related with the improvement of the structure of the movable contact which opens a pole.

  In a conventional circuit breaker, when an excessive current such as a short circuit current flows in the main circuit, the switching mechanism trips using an electromagnetic repulsive force acting between the fixed contact and the movable contact. Faster than that, the movable contactor is driven from the closed position to the open position, and an arc extinguishing chamber equipped with a grid plate is arranged in the open / close movement path of the movable contact so that the arc generated between the fixed contact and the movable contact Is limited in the arc extinguishing chamber (see, for example, Patent Document 1).

JP 2007-115539 A (paragraph number 0002)

  In the conventional circuit breaker described above, when a large current flows through the circuit breaker due to a short circuit or the like, an electromagnetic repulsive force is generated between the contacts, and the movable contact is separated from the closed position to the open position. At this time, the movable contact rotates around the movable contact axis, but the crossbar cannot keep up with the rotation speed, and rotates behind the movable contact.

  For this reason, a large gap is opened between the movable contact and the cross bar. Further, when the short-circuit current is interrupted, an arc is generated between the movable contact and the fixed contact, and the grid, both contacts, and their contacts are melted by the extremely high heat, and the metal particles are scattered. The metal particles solidified after cooling become a melt and remain in the circuit breaker. When the remaining melt enters the gap between the movable contact and the cross bar, the rotation of the movable contact is hindered. As a result, since the movable contact does not rotate smoothly, a contact failure such as a contact failure due to the handle, a decrease in contact pressure, or a contact failure does not occur even if it can be inserted.

  Furthermore, when the shape of the movable contact is large and the length is long, the electromagnetic repulsion becomes dull and there is a problem that the improvement of the arc extinguishing performance due to the electromagnetic repulsion is suppressed.

  The present invention has been made in order to solve the above-described problems, and is a circuit breaker capable of improving the contact failure of a contact and the failure of turning on of a handle with a high electromagnetic repulsion operation of a movable contact and high arc extinguishing performance. The purpose is to obtain.

  In order to achieve the above object, the present invention provides an opening / closing mechanism connected to a tilting operation handle, and a crossbar connected to the opening / closing mechanism and rotated by the operation of the opening / closing mechanism. And a movable contact that has a movable contact at one end, is pivotally supported in the crossbar so that the other end can be rotated, and that opens and closes in conjunction with the rotation of the crossbar. A circuit breaker provided with a fixed contact that has a fixed contact at one end to which the movable contact contacts and separates so that the movable contact is electromagnetically repelled and separated when a large current flows from the movable contact to the fixed contact The movable contact is separated into a first movable contact on the movable contact portion side and a second movable contact on the pivot support portion side at an intermediate point between the pivot support portion and the movable contact portion, and One movable contact is electromagnetically repelled against the second movable contact As it can be rapidly bent pivots away direction, in which the first movable contact and second movable contact is connected by rotating shaft.

  Then, in a state where the first movable contact is electromagnetically repelled, the end surface of the second movable contact is in a state where the main passage to the crossbar side of the generated arc gas is blocked, and the gap between the crossbar and the movable contact This is intended to suppress the scattering of metal particles.

  As described above, the present invention improves the reliability at the time of interruption by suppressing the influence of the melt remaining due to the occurrence of the arc while the first movable contact sharply repels the electromagnetic and enhances the arc extinguishing performance. A circuit breaker can be obtained.

Embodiment 1 FIG.
1A and 1B are diagrams showing an open circuit state of a circuit breaker according to Embodiment 1 of the present invention. FIG. 1A is an internal side view showing the whole, and FIG. 2A and 2B are views showing a state in which the handle is operated to be in a closed state from the state of FIG. 1, FIG. 2A is an internal side view showing the whole, and FIG. 2B is a detailed view of a main part. In FIG. 1, a power supply side fixed contact 3 fixed to the base 1 and a fixed contact 4 fixed to one end of the power supply side fixed contact 3 are provided in an insulating housing composed of a base 1 and a cover 2. The other end of the power supply side fixed contact 3 is formed as a power supply terminal for connecting a power supply conductor (not shown).

  A first movable contact 6 is provided opposite to the power supply side fixed contact 3, and a movable contact 5 that contacts the fixed contact 4 is fixed to the tip of the contact. The first movable contact 6 is rotatably coupled to the second movable contact 7 by a shaft 6a and is also electrically coupled. The first movable contact 6, the shaft 6a, and the second movable contact 7 are made of a highly conductive material such as copper, and the second movable contact 7 is made of a highly conductive material plate material U. It is formed by bending it into a letter shape.

  As is well known, the crossbar 8 is a multipole circuit breaker that simultaneously operates the second movable contactor 7 of each pole, and is formed of a heat-resistant and mechanically high-strength insulating material. Has been. The cross bar 8 is rotated by a handle 10 via an opening / closing mechanism 9 by a toggle link mechanism, and the opening / closing operation of the second movable contact 7 is performed. In this configuration, the first movable contact 6 receives a moment counterclockwise around the shaft 6a by the twist spring 14 and is locked at a predetermined position. Accordingly, the second movable contact 7 and the first movable contact 6 rotate integrally when the handle 10 is operated to perform an opening / closing operation.

  FIG. 2 is a diagram illustrating a state in which the movable contact 5 is brought into contact with the fixed contact 4 to be in a closed state by operating the handle 10 from the state of FIG. In this closed state, the current flowing through the circuit breaker is as follows: power source side fixed contact 3, fixed contact 4, movable contact 5, first movable contact 6, second movable contact 7, second movable contact 7 Flows in the order of the sliding member 11, the heater 12, and the load side terminal 13. In this configuration, the sliding member 11, the heater 12, the load side terminal 13, the overcurrent tripping mechanism, and the like are well known and are not related to the present invention, and thus the description thereof is omitted.

  In the above configuration, the mutual relationship between the details of the first movable contact 6, the second movable contact 7, and the crossbar 8 will be described. In the state of FIG. 1, the contact portion 6b of the first movable contact 6 and The contact portion 7b of the second movable contact 7 is in contact. Further, the rotation shaft root portion 6c of the first movable contact 6 abuts on the movable member receiving surface 8a of the cross bar 8, and therefore the second movable contact 7 has a slight contact portion 7b with the movable member receiving surface 8a. It is maintained in a state where a gap is generated.

  The first movable contact 6 and the second movable contact 7 are in contact with the second movable contact 7 until the movable contact 5 comes into contact with the fixed contact 4 at the time of shifting to the closed state of FIG. The first movable contact 6 is rotated about the shaft 6a after contact, and a contact pressure is obtained by the twist spring 14, and at the same time the contact portion of the contact portion is rotated. Get overtravel and wipe. Therefore, the rotation shaft root portion 6c has a slight gap from the mover receiving surface 8a. At this time, the second movable contact 7 rotates in the cross bar 8 around the shaft 7a until the contact portion 7b contacts the mover receiving surface 8a.

  In the operation of shifting from the closed state to the open state, after the contact is released, the first movable contact 6 is brought into contact with the contact portion 6b and the contact portion 7b by the moment received by the twist spring 14 around the shaft 6a. In addition, the rotation shaft root portion 6c comes into contact with the mover receiving surface 8a and returns to the open state. At that time, the arc extinguishing chamber 15 having the grid plate 15a arranged on the moving path of the first movable contact 6 is configured to cut off the current generated when the large current is cut off.

  FIG. 3 shows that the first movable contact 6 rotates from the closed position to the open position around the shaft 6a without waiting for the operation of the opening / closing mechanism 9 that drives the crossbar 8 due to the electromagnetic repulsive force due to the generation of the short-circuit current. Indicates the state of movement. As described above, when a large current such as a short-circuit current is generated, the second movable contact 7 does not rotate, and only the first movable contact 6 rapidly rotates about the shaft 6a. The shaft 6a is disposed closer to the contact side of the crossbar 8. In the closed state, the contact portion 7b is in contact with the mover receiving surface 8a, so that the opening / closing mechanism portion 9 that drives the crossbar 8 is used. Regardless of whether or not is operating, there is no gap between the cross bar 8 and the second movable contact 7.

  Thus, during the current limiting opening, only the first movable contact 6 rotates about the shaft 6a. Since the shaft 6a is disposed closer to the contact point when viewed from the crossbar 8, the shaft 6a has a small shape and operates sharply against electromagnetic repulsion. In the closed state, the contact portion 7b is in contact with the mover receiving surface 8a so as to block the arc gas passage, so that the grid, the two contacts, and their contacts, etc. are generated by an arc caused by a large current. As a result, the molten material does not enter between the cross bar 8 and the second movable contact 7. Therefore, the rotation of the movable contact is hindered, the handle is not inserted properly, and the reliability at the time of interruption can be improved.

Embodiment 2. FIG.
In addition, as shown in FIG. 3B, in the vicinity of the movable contact 5 of the first movable contact 6, for example, an arc extinguishing insulating material composition disclosed in JP-A-7-302535 is used. If the protective cover 20 made of an insulating material that ejects gas is arranged, the contact direction when the first movable contact 6 is rotated about the shaft 6a and receives heat from an arc due to a large current. Because the gas is blown out and the arc is driven in the contact direction with this gas pressure, the current limiting effect is further enhanced, and the scattered melt is less likely to move to the crossbar 8 side. Can be improved.

It is an internal side view which shows an open state in the circuit breaker which shows Embodiment 1 of this invention. It is an internal side view which shows a closing state in the circuit breaker of FIG. It is an internal side view which shows the state which the 1st movable contact rotated by the electromagnetic repulsive force by short circuit current generation | occurrence | production in the circuit breaker of FIG.

Explanation of symbols

1 base,
2 Cover 3 Power supply side fixed contact,
4 fixed contact 5 movable contact,
6 first movable contact, 6a shaft, 6b contact portion, 6c rotation shaft root portion,
7 second movable contact, 7a shaft, 7b contact portion,
8 Crossbar, 8a Movable receiving surface,
9 Opening / closing mechanism,
10 Handle,
11 sliding member,
12 heaters,
13 Load side terminal,
14 Twist spring,
15 Arc extinguishing chamber, 15a Grid plate.

Claims (3)

  An open / close mechanism connected to a tilting operation handle, a crossbar connected to the open / close mechanism and rotated by the operation of the open / close mechanism, a movable contact at one end, and the like A movable contact that is pivotally supported in the crossbar so that the end can be rotated and that opens and closes in conjunction with the rotation of the crossbar, and a fixed contact between the movable contact and the movable contact. A circuit breaker comprising a fixed contact having a contact at one end, wherein the movable contact is electromagnetically repelled and separated when a large current flows from the movable contact to the fixed contact. Is composed of a first movable contact on the movable contact portion side and a second movable contact on the pivot support portion side at an intermediate point between the pivot support portion and the movable contact portion, and the first movable contact. The child is electromagnetic with respect to the second movable contact As can flex pivots HatsuHirakiHanare direction, the circuit breaker, characterized in that the first movable contact and second movable contact are connected by rotating shaft.   When the first movable contact is rotated by electromagnetic repulsion and arc gas is generated between the movable contact and the fixed contact, the end face of the second movable contact seals a part of the arc gas passage. The circuit breaker according to claim 1.   The circuit breaker according to claim 1 or 2, wherein a protective cover made of an arc extinguishing insulating material composition is provided in the vicinity of the movable contact of the first movable contact.

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