JP4889339B2 - Circuit breaker for wiring - Google Patents

Description

  The present invention relates to a circuit breaker for wiring in which contact can be easily peeled off when contact welding occurs.

  The circuit breaker can be switched on and off by opening and closing the handle lever, and when an overcurrent is detected, the trip mechanism operates to move the movable contact and turn off the contact to shut off the circuit. It is a thing. At this time, the handle lever moves to the trip position, indicating that the circuit has been interrupted. In this way, it is designed so that the open / close state of the contact is correctly displayed according to the handle lever position.

  However, if the contact is welded due to overcurrent, the movable contactor or contact remains on even though the trip mechanism is operating, and the normal relationship between the handle lever position and the contact is lost. . In a normal circuit breaker, the welded contact cannot be peeled off even if the handle lever is operated. It is also possible to move the handle lever to the off position while the contacts are welded, and because the handle lever is in the off position, it is believed that the circuit is in a non-energized state, and there is a possibility of causing an electric shock accident. .

  In order to solve such a problem, Patent Documents 1 and 2 disclose that the handle lever cannot be moved to the off position when the contact is welded. A circuit breaker has been proposed in which the contact can be peeled off by moving it strongly in the direction. However, in the circuit breaker disclosed in Patent Document 1, when the handle lever is turned off in the contact welding state, the protrusion of the handle lever is brought into direct contact with the crossbar pin, and the movable contact is moved in parallel with the contact surface with the fixed contact. Structure. For this reason, since the distance from the rotation axis of the crossbar is short and sufficient rotation torque cannot be applied to the crossbar, the force to peel off the welded contact is weak.

The circuit breaker disclosed in Patent Document 2 has a structure in which the trip bar is operated and the contact is peeled off by the spring force of the trip mechanism with respect to welding when the trip mechanism is not operating. It was not possible to peel off the contact weld in a state where the was operated.
JP 2005-63877 A JP 2000-32003 A

  The present invention solves the above-described conventional problems, and when the contact is welded, the handle lever cannot be moved to the off position, and the contact welding in a state where the trip mechanism is operated can be peeled off with a strong force. It was made to provide a circuit breaker for wiring.

  The present invention, which has been made to solve the above-described problems, transmits the movement of the handle lever to the crossbar via the lower link, and in the wiring breaker that opens and closes the contact, the handle lever is turned off in the contact welded state. The release member whose one end is sometimes pushed down by the protrusion of the handle lever is pivotally attached to the cross bar, and the other end is engaged with the lower link to be an engaging portion for pulling up the lower link. . In addition, it is preferable to form the step part engaged with the engaging part of the other end of a separating member in the lower link.

  In the circuit breaker of the present invention, the release member is pivotally attached to the cross bar. It is a structure that pushes up and pulls down the lower link to peel off the welded contact. For this reason, in a state where the contacts are welded, the handle lever cannot be moved to the OFF position unless the separating member is rotated. Moreover, since the lower link is pulled up, the contact welding can be peeled off with a stronger force than the conventional one in which the cross bar is directly rotated. Since the contact is peeled off by operating the handle, the contact weld can be peeled off even when the trip mechanism is operating.

Preferred embodiments of the present invention are shown below.
FIGS. 1 to 3 are views showing an internal mechanism in the ON state of the circuit breaker according to the embodiment. In these drawings, reference numeral 1 denotes a handle lever having a handle (not shown) fixed to the upper end, which is supported by the frame with the lower end portion 2 as a rotation shaft. A shaft 3 connects the upper link 4 and the lower link 5, and a toggle spring 6 is provided between the shaft 3 and the upper end of the handle lever 1.

  The upper end of the upper link 4 is pivotally supported by a shaft 8 at the center of the latch 7. One end of the latch 7 is pivotally supported by the shaft 9 on the frame, and the tip is engaged with the lower surface of the trip bar 10. Further, the lower end of the lower link 5 is connected to the cross bar 12 by a shaft 11. The crossbar 12 can rotate around the crossbar shaft 13. A movable contact 15 is provided at the tip of the movable arm 14 of each pole fixed to the crossbar 12, and the circuit can be opened and closed with the fixed contact 16. It can be performed.

  In the on state shown in FIG. 3 and the off state shown in FIG. 4, the latch 7 does not move, so that the shaft 8 is in a fixed position. When the handle lever 1 is moved from the on position shown in FIG. 3 to the off position shown in FIG. 4, when the operating point of the toggle spring 6 is exceeded, the upper link 4 rotates counterclockwise about the shaft 8 and moves accordingly. Since the position of the shaft 3 moves to the crossbar shaft 13 side, the lower link 5 is pulled up. As a result, the cross bar 12 rotates and the movable arm 14 rises, and the movable contact 15 leaves the fixed contact 16 and the contact is turned off.

  When an overcurrent is detected, the trip bar 10 moves as shown in FIG. 5 to disengage the tip of the latch 7, and the latch 7 can rotate about the shaft 9. For this reason, the toggle spring 6 pulls up the upper link 4 together with the latch 7, the lower link 5 connected by the shaft 3 also moves upward, the movable arm 14 rises, the movable contact 15 moves away from the fixed contact 16, and the contact is Turn off. In this trip state, the handle lever 1 takes the trip position shown in FIG. As described above, the movement of the handle lever 1 is transmitted to the crossbar 12 via the lower link 5, and the opening and closing of the contacts is the same as in the conventional circuit breaker.

  However, in the circuit breaker for wiring according to the present invention, the separating member 17 having a shape as shown in FIG. 6 is pivotally attached to the cross bar 12. The separating member 17 includes L-shaped bent arms 18 and 18 on both sides and a connecting plate 19 that connects the upper surfaces of the arms 18 and 18. It is attached freely. The separating member 17 is always urged counterclockwise by the spring (not shown), that is, the tip of the arm 18 is lowered.

  Further, projecting pieces 21 as shown in FIG. 7 are provided on both sides of the handle lever 1 slightly below the middle portion thereof, and a connecting plate that is one end of the separating member 17 at the lower end of the projecting piece 21. The end of 19 can be pushed down. Note that the tip of the arm 18, which is the other end of the separating member 17, is engaged with a step portion 22 formed on the upper side surface of the lower link 5 and serves as an engaging portion 23 that forcibly pulls up the lower link 5. .

The operation of the circuit breaker of the present invention thus configured is as follows.
As described above, since the separating member 17 is always urged by the spring in the direction in which the tip of the arm 18 is lowered, the normal on / off operation shown in FIGS. 3 and 4 and the trip operation shown in FIG. 5 are performed. In some cases, it does not interfere with other members. Therefore, these normal operations are performed without any change from the conventional circuit breaker.

  However, when the contact welding state is reached as shown in FIG. 8, if the handle lever 1 is turned off as shown in FIG. 9, the crossbar 12 does not rotate unlike the normal off operation. The projecting piece 21 hits one end of the separating member 17 and pushes it down to try to rotate the separating member 17 clockwise against the spring. However, since the engaging portion 23 at the other end of the separating member 17 is engaged with the step portion 22 of the lower link 5, the separating member 17 cannot rotate any more in the contact welding state. Accordingly, the handle lever 1 cannot be turned off in the contact welding state, and when the hand is released from the handle, the handle lever 1 returns to the on position by the force of the toggle spring 6. For this reason, the handle lever 1 does not take the OFF position in spite of the contact welding state, and the risk of an electric shock as described above can be eliminated.

  Further, when the handle lever 1 is turned off by further applying force from the state of FIG. 9, the engaging portion 23 at the other end of the separating member 17 is depressed by pushing down one end of the separating member 17 by the projecting piece 21 of the handle lever 1. It is possible to push up and pull up the lower link 5 engaged therewith to peel off the welding of the contact. At this time, since there is a distance between the crossbar shaft 13 and the shaft 11 of the lower link 5, the movable arm 14 can be pulled up by rotating the crossbar 12 with a strong force while securing a sufficient lever ratio. The welded contact can be peeled off more easily than the conventional circuit breaker in which the bar 12 is directly rotated.

  As described above, the circuit breaker according to the present invention cannot be brought into the off position even if the handle lever 1 is operated in the off direction in the contact welded state, and the normal relationship between the handle lever position and the contact point. Even when the trip mechanism is in operation, the handle lever 1 can be turned off by applying more force, so that the contact can be more easily peeled off than the conventional circuit breaker. It is what you have.

It is a perspective view which shows the internal mechanism in an ON state. It is a back perspective view which shows the internal mechanism in an ON state. It is a sectional structure figure showing an internal mechanism in an ON state. It is a sectional structure figure showing an internal mechanism in an off state. It is a sectional structure figure showing an internal mechanism in a trip state. It is a perspective view of a separating member. It is a perspective view of a handle lever. It is a sectional structure figure showing an internal mechanism in a contact welding state. It is a cross-sectional structure figure when peeling off the welded contact.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Handle lever 2 Lower end part 3 Axis 4 Upper link 5 Lower link 6 Toggle spring 7 Latch 8 Axis 9 Axis 10 Trip bar 11 Axis 12 Crossbar 13 Crossbar axis 14 Movable arm 15 Movable contact 16 Fixed contact 17 Release member 18 Arm 19 Connecting plate 20 Hole 21 Projection piece 22 Step part 23 Engagement part

Claims (2)

  In a circuit breaker that opens and closes contacts by transmitting the movement of the handle lever to the crossbar via the lower link, when the handle lever is turned off with the contact welded, one end is pushed down by the protrusion of the handle lever. A breaker for wiring, characterized in that a member is pivotally attached to a cross bar, and the other end is engaged with a lower link to raise the lower link.   2. The circuit breaker according to claim 1, wherein a step portion that engages with an engaging portion at the other end of the separating member is formed on the lower link.

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