JP4440872B2 - Circuit breaker movable contact device - Google Patents

Description

  The present invention relates to a movable contact device for a circuit breaker such as a circuit breaker for a wiring or an earth leakage circuit breaker, and more particularly to downsizing of a device and stabilization of an electrical connection state in a sliding contact system.

  The circuit breaker has a function to open and close an electric circuit by operating the operation handle provided in the circuit breaker, that is, not only a switch function, but also prevent electric wires and load equipment from being burned out due to overcurrent. In order to do so, it plays a big role of cutting off the electric circuit. One of the important parts for satisfying these functions of the circuit breaker is a movable contact that contacts the fixed contact in the closed state and separates from the fixed contact in the open state. The current-carrying member connected to this literally “movable” contactor is a small circuit breaker that has a space-constrained shunt, especially a copper shunt wire or a shunt made of laminated thin plates that is flexible. Employed mainly with a rated current of 30 to 100 A (ampere).

  However, since this shunt faces the problem of fatigue disconnection in the aforementioned opening / closing function, the opening / closing life must be limited. Therefore, as one means for improving the open / close life, the movable contact and the connection conductor are brought into sliding contact, and the contact spring disposed outside the connection conductor is used to increase the contact pressure between the movable contact and the connection conductor. An energization mechanism is known. Since the electric contact between the movable contact and the connecting conductor does not use a shunt, it is generally called a “shuntless energization mechanism” (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-6681 (page 3, right column, lines 23 to 28, FIG. 1)

  According to FIG. 1 of Patent Document 1, since two movable contacts are arranged in parallel per pole, it is assumed that the circuit breaker has a large current carrying capacity, for example, a rated current of about 400 A. Also, in order to prevent the movable contacts from attracting each other and coming into contact with each other due to the electromagnetic force acting between the movable contacts when a large current flows, a small gap is formed between the movable contacts. You can see that they are wearing.

  However, the above-mentioned suction force acting between the movable contacts may cause the movable contact to incline due to the point contact between the gap top and the movable contact. This inclination may cause the contact between the movable contact and the connection conductor to become unstable. Further, the contact spring is arranged on the outer surface of the connection conductor, and the connection conductor is pressed against the movable contact so that an electrical connection can be obtained. Therefore, in order to maintain stable electrical connection with the movable contact by this pressing, the thickness of the movable contact and the inner dimension of the connecting conductor sandwiching the movable contact must be strictly controlled.

  Furthermore, since it is the structure which presses a connection conductor, a connection conductor will be formed with a material with thin plate | board thickness so that it may bend easily. When the plate thickness is thin, in addition to the above-described dimension control, it is necessary to pay close attention to the part management during the manufacturing process such as deformation. Further, since the plate thickness is thin, there is a restriction on increasing the current carrying capacity. Furthermore, in combination with the increase in the outer dimensions of the shuntless energization mechanism itself by arranging the contact spring described above, it has been difficult to apply to a circuit breaker having a larger rated current.

  The present invention has been made to solve the above-described problems, and is a circuit breaker in which the contact between the movable contact and the mover receiver (corresponding to the connection conductor of Patent Document 1) is stable and can be reduced in size. It is an object to obtain a movable contact device.

In the movable contact device for a circuit breaker according to the present invention, the energizing mover in which the other end of the movable contact having a movable contact at one end and the other end formed in a flat plate shape has a pair of connection conductor portions. In the movable contact device of the circuit breaker, which is held in an electrically connected state by the connecting conductor portion of the receiver and is pivotally supported and can be opened and closed with respect to the fixed contact by an opening and closing mechanism. The configuration of one pole of the movable contact is configured by arranging two movable contact bodies each having a movable contact at one end in parallel, and the two movable contacts at the other end of the shaft support portion. An elastic member is sandwiched between the contact bodies, and a suction suppression member is sandwiched at a position closer to the shaft support portion side than the middle between the movable contact and the shaft support portion.

  As described above, the present invention provides a shuntless energization mechanism that is small and has a large energization capability, so that the open / close life of the medium or large circuit breaker is improved and the electrical connection between the movable contact and the mover receiver is achieved. The state is stable.

Embodiment 1 FIG.
1 is a side sectional view showing a closed state of a circuit breaker according to Embodiment 1 of the present invention, and FIG. 2 is a partial sectional view taken along line AA in FIG.

  In FIG. 1, a cover 1 and a base 2 constitute a casing of the circuit breaker 101, and are each formed of a synthetic resin material. An opening / closing mechanism 102 is accommodated in the base 2, and a handle 3 interlocking with the opening / closing mechanism 102 projects from the handle window hole 1 a of the cover 1 to the surface of the cover 1. As is well known, the handle 3 can be manually operated from the outside. Depending on the position of the handle 3 of the circuit breaker 101 in the closed state, on the paper, the right side is, for example, a connection terminal portion (not numbered) for connecting a power supply side electric wire, and the left side is, for example, a connection terminal for connecting a load side electric wire. As is well known, it is a part (not numbered).

In the above circuit breaker, the fixed contact 4 constituting the connection terminal portion with the power supply side electric wire is fixed to the base 2 by the mounting screw 5, and the fixed contact 6 fixed to one end of the fixed contact 4 is a movable contact. The circuit breaker 101 is opened / closed, that is, the electric circuit is turned on / off by contacting / disconnecting with the movable contact 7 fixed to one end of the child 8.
In this opening and closing operation, the movable contact 8 is supported by the shaft 9 (see FIG. 2) via the mover receiver 11, and the crossbar 10 that holds the movable contact 8 is connected to the opening / closing mechanism 102. Therefore, the opening / closing is performed according to the operation of the opening / closing mechanism 102. Since this opening / closing operation does not form a main part of the present invention, detailed description thereof is omitted.

  In the above description, the movable contact 8 is clamped by the movable receiver 11, which is fixed to the base 2 by the mounting screw 12 and connected to the relay conductor 14 by the mounting screw 13. The relay conductor 14 is connected to a load conductor 15 constituting a connection terminal portion with a load side electric wire via a heater constituting an overcurrent tripping device (not shown). Therefore, the current path in this closed state is the fixed contact 4 → the fixed contact 6 → the movable contact 7 → the movable contact 8 → the movable contact 11 → the relay conductor 14 → the heater → the load conductor 15, and the shuntless without using the shunt. It turns out that the electricity supply mechanism is comprised. Hereinafter, the movable contact 8 and the movable receiver 11 will be mainly described.

In FIG. 2, the mover receiver 11 includes a base portion 11a including a screw hole (not shown) into which the mounting screw 12 is screwed, and a first through hole 11c through which the mounting screw 13 passes, and the base portion 11a. It is formed integrally with a pair of connecting conductor portions 11b that are raised at a right angle, have opposite ends, and have a second through hole 11d through which the shaft 9 passes. In addition, as a material for forming the mover receiver 11, a copper plate having good conductivity is used, and a plate thickness and a shape that are not easily deformed are considered.
On the other hand, as described above, the movable contact 8 has the movable contact 7 fixed to one end and a through hole 8a at the other end. The shaft 9 is passed through the through hole 8a to move the movable contact 11 The second through hole 11d is rotatably supported. The crossbar 10 holds both ends of the shaft 9 and holds the movable contact 8 so that the movable contact 8 responds to the operation of the opening / closing mechanism 102.

As is apparent from FIG. 2, the movable contact 8 is intended to be applied to a medium or large circuit breaker by arranging two movable contact members 81 and 82 in parallel.
A counterbore 8b is provided in a portion of the through-hole 8a on the opposing surfaces of the movable contact members 81 and 82 arranged side by side, that is, on both inner surfaces opposite to the surface in contact with the mover receiver 11. . Both ends of the elastic member 16 loosely fitted to the shaft 9 are fitted to the counterbore 8b. Although various spring materials can be considered as the elastic member 16, the illustrated elastic member 16 shows an embodiment using a helical spring. By the elastic member 16 sandwiched between the movable contact bodies 81 and 82 arranged side by side, the contact portion 8c of the movable contact 8 is pressed against the connection conductor portion 11b, and surface contact can be maintained. . This surface contact stabilizes the electrical contact state between the movable contact 8 and the movable receiver 11. Further, since it is not necessary to bend the connecting conductor portion 11b, the connecting conductor portion 11b can be made thicker, and the current-carrying capacity according to the medium / large circuit breaker can be accommodated.
Although the elastic member 16 is an example of a helical spring, when the parallel arrangement interval of the pair of movable contacts 8 is made narrow, both ends of a leaf spring or a thin helical spring are connected. A spring formed in a ring shape is suitable.

  As described above, since the movable contact 8 is configured by arranging two movable contact bodies 81 and 82 in parallel, as shown in Patent Document 1, it is movable when a large current flows. An attractive force is generated between the contact bodies 81 and 82 by an electromagnetic force. As the movable contact 8, it is necessary to suppress the contact of the movable contact bodies 81 and 82 due to this suction force. Therefore, in the present invention, as shown in FIG. 2, the suction suppression member 17 is fixed to either one of the movable contact bodies 81 and 82 by means such as rivets or adhesion. The suction suppression member 17 is suitably a synthetic resin material such as nylon, but can also be formed of a metal material. In this way, in combination with the surface contact with the movable contact 8, the suction suppression member 17 can stably maintain the contact state between the movable contact 8 and the movable receiver 11 when a large current is passed. It is possible to prevent welding due to arcing between the two parts.

  In short, in the movable contact device of the present invention, the elastic member 16 is sandwiched between the movable contact bodies 81 and 82 arranged side by side, and the intermediate portion between the movable contact and the pivot support portion. Since the suction suppression member is sandwiched, a small shuntless energization mechanism that does not cause welding due to arcing can be provided. Moreover, according to this structure, the open / close life of the middle- or large-sized circuit breaker can be improved.

Embodiment 2. FIG.
FIG. 3 is a view corresponding to FIG. 2 in the second embodiment of the present invention. In FIG. 3, the suction suppression member 17 is sandwiched and fixed on the shaft 9 side with respect to the intermediate position between the movable contact 7 and the shaft 9. That is, the dimension a from the contact 7 to the position of the suction suppression member 17 is made larger than the dimension b from the position of the suction suppression member 17 to the shaft 9. When configured in this way, the attractive force when passing a large current acts more strongly on the contact side than on the shaft 9 side. Therefore, the suction force acts so as to open the space between the movable contact bodies 81 and 82 on the shaft 9 side with the suction suppression member 17 as a fulcrum. Since this action works so that the movable contact 8 is pressed against the movable receiver 11, the contact state between the movable contact 8 and the movable receiver 11 is further stabilized.

Embodiment 3 FIG.
4 is a view corresponding to FIG. 2 in Embodiment 3 of the present invention, and FIG. 5 is a sectional view taken along line BB in FIG.
In the figure, the vibration suppression portion 18a is brought into contact with both outer side surfaces of the movable contactor 8, that is, the outer side surfaces where the suction suppression member 17 is sandwiched among the surfaces contacting the connecting conductor portion 11b. As shown in FIG. 5, the vibration restraining member 18 is formed by connecting the vibration restraining portions 18a on both outer side surfaces by the connecting portion 18b on the movable contact 7 side. Further, the vibration suppression member 18 and the suction suppression member 17 are integrally coupled as illustrated. In this case, the vibration suppression member 18 and the suction suppression member 17 may be separate parts, but if they are formed of a synthetic resin material, the vibration suppression member 18 and the suction suppression member 17 can be integrally molded. is there.
When the circuit breaker receives vibration / impact, the movable contact 8 may move outwardly. However, by providing the vibration suppression member 18 together with the suction suppression member 17 as described above, vibration / Can suppress movement caused by impact. Therefore, the contact state between the movable contact 8 and the movable receiver 11 is further stabilized.

Embodiment 4 FIG.
6 and 7 correspond to FIGS. 1 and 5 according to the fourth embodiment of the present invention. In FIG. 6, arc insulation that prevents arc jumping to the crossbar 10 side and discharges gas that induces the arc to the power source side at the time of overcurrent interruption is provided near the movable contact 7 on both side surfaces of the movable contact 8. 1 except that a member (vibration suppressing member 18 described later) is fixed.

As shown in FIG. 7, the arc insulating member is fixed to the movable contact 8 so as to hold both side surfaces of the movable contact 8. That is, the feature of the fourth embodiment is that the vibration suppressing member 18 described in the third embodiment (FIG. 5) has an arc insulation function. In order to provide this arc insulating function, the material of the vibration suppressing member 18 is, for example, polyethylene terephthalate as shown in Patent No. 3359422 as a material for arc extinguishing insulating material composition and arc extinguishing insulating material molded body. Nylon 66, nylon 46, etc. are suitable. In addition, when integrating the vibration suppression member 18 and the suction suppression member 17, the suppression member 18 and the suction suppression member 17 may be integrally formed using these materials.
According to this embodiment, the contact state between the movable contact 8 and the movable receiver 11 is stabilized, and the interruption performance is improved by the arc extinguishing gas generated when the arc touches the arc insulating member 18. To do.

It is a sectional side view of the circuit breaker in Embodiment 1 of this invention. It is a fragmentary sectional view which follows the line AA in FIG. It is a fragmentary sectional view equivalent to FIG. 2 in Embodiment 2 of this invention. It is a fragmentary sectional view equivalent to FIG. 2 in Embodiment 3 of this invention. It is a fragmentary sectional view which follows the line BB in FIG. It is a sectional side view equivalent to FIG. 1 in Embodiment 4 of this invention. FIG. 6 is a partial view corresponding to FIG. 5 in Embodiment 4 of the present invention.

Explanation of symbols

    1 Cover, 1a Handle window hole, 2 Base, 3 Handle, 4 Fixed contact, 6 Fixed contact, 7 Movable contact, 8 Movable contact, 8a Through hole, 8b Counterbore, 8c Contact part, 9 axis, 10 Cross Bar, 11 Mover receiver, 11a Base, 11b Connection conductor, 14 Relay conductor, 15 Load conductor, 16 Elastic member, 17 Suction suppression member, 18 Vibration suppression member, 81 Movable contact body, 82 Movable contact body, 101 Circuit breaker, 102 Opening / closing mechanism.

Claims (3)

The other end of the movable contact having a movable contact at one end and a flat end at the other end is sandwiched in an electrically connected state by the connection conductor portion of the energizing mover receiver having a pair of connection conductor portions. In the movable contact device for a circuit breaker that is pivotally supported and can be opened and closed with respect to the fixed contact by an opening / closing mechanism, the configuration of one pole of the movable contact is each one end Two movable contact bodies having movable contacts are arranged in parallel, and an elastic member is sandwiched between the two movable contact bodies at the shaft support portion at the other end, A movable contact device for a circuit breaker, characterized in that a suction suppression member is sandwiched at a position closer to the pivot portion side than the middle between the movable contact and the pivot portion. The suction suppression member is integrally provided with a vibration suppression member formed by a vibration suppression portion that contacts both outer surfaces of the movable contact and a connection portion that connects the two vibration suppression portions on the movable contact side. The movable contact device for a circuit breaker according to claim 1 . The movable contact device for a circuit breaker according to claim 2 , wherein the vibration suppressing member is made of a material that generates an arc extinguishing gas when touched by an arc generated when the circuit breaker is interrupted.

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