JP2001210216A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve current breaking performance by preventing suppression in switch opening speed of a movable contact table during switch opening operation of a breaker. SOLUTION: The circuit breaker comprises a fixed contact table having fixed contacts and a movable contact table having movable contacts, and a switching mechanism in which the movable contact table is biased to a switch opening position where the movable contacts are contacted with the fixed contacts, and the movable contact table is biased to a switch closing position where the movable contacts are not contacted with the fixed contacts by a rotation driving force transferring mechanism that transfers operation force of an operation laver and rotatably derives the movable contact table. The movable contact table is provided with a movable contact table driving spring, and the movable contact table driving spring biases the movable contact table to the switch-closing position when the movable contact table is in the vicinity of the switch closing position and the movable contact table to the switch opening position when the movable contact table is in the vicinity of the switch opening position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker, and more particularly to a circuit breaker for separating a movable contact stand from a fixed contact stand by the action of electromagnetic repulsion.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional circuit breaker. In the figure, 2 is an inner case, 20 is a movable contact drive spring, 400 is a fixed contact stand, 401 is a fixed contact, 500
Denotes a movable contact stand, 501 denotes a movable contact, and 600 denotes a rotational driving force transmission rod. The rotational driving force transmission rod 600 supplies a rotational driving force from an opening / closing mechanism (not shown) to the movable contact stand 500. The movable contact drive spring 20 is a tension spring,
The movable contact stand 500 is constantly pressed against the fixed contact stand 400. The breaking part of the circuit breaker including the fixed contact base and the movable contact base is attached to the inner case 2 and housed in a case (outer case) (not shown).

At the time of current interruption, the movable contact block is separated from the fixed contact block by the electromagnetic repulsive force of the current flowing through the fixed contact block 400 and the movable contact block 500, and the current flowing through the main circuit is quickly limited. The rotary drive force transmission rod has a latch mechanism that latches the movable contact block when the movable contact block reaches the open circuit position, and prevents the movable contact block from returning to the fixed contact block again by the retraction force of the spring. Is provided.

[0004]

In the conventional circuit breaker, when the circuit breaker is opened, a force for pulling the movable contact base 500 toward the fixed contact base 400 by the movable contact drive spring always acts on the movable contact drive spring 20. Therefore, the movable contact block 500
The opening operation speed of the motor decreases. When the main circuit current decreases and the electromagnetic force acting in the direction to open the movable contact decreases, the movable contact table 5 is driven by the driving force of the movable contact drive spring.
A latch mechanism for latching the movable contact block so that 00 is not pulled back to the fixed contact block 400 is required, and the latch mechanism also suppresses the opening operation speed of the movable contact block 500. The present invention has been made in view of the above problems,
Provided is a circuit breaker that prevents the opening speed of the movable contact block 500 from being suppressed during the opening operation and improves the overcurrent interrupting performance.

[0005]

The present invention employs the following means in order to solve the above-mentioned problems.

A fixed contact block having a fixed contact and a movable contact block having a movable contact, a rotary drive transmitting mechanism for transmitting an operation force of an operating lever to rotate the movable contact block, and a transmission of the rotational drive A circuit breaker having a mechanism for urging the movable contact block to a closed position where the movable contact contacts the fixed contact and a switching mechanism for biasing the movable contact block to the open position where the movable contact does not contact the fixed contact. Wherein the movable contact stand includes a movable contact stand drive spring formed of a snap spring or the like, and the movable contact stand drive spring biases the movable contact stand toward the closed position when the movable contact stand is in the vicinity of the closed position. When the contact block is opened above a predetermined value, the movable contact block is urged toward the open position. Further, the rotation driving force transmission mechanism includes a transmission rod having a convex portion for transmitting the operation force from the operation lever to the movable contact stand.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 are cross-sectional views of one pole of a circuit breaker according to an embodiment of the present invention,
FIG. 1 is a diagram showing a closed position, FIG. 2 is a diagram showing an open position, and FIG. 3 is a diagram showing an open position.

In these figures, reference numeral 2 denotes an inner case for mounting a contact base, an arc chute, a spring, etc., 20 denotes a movable contact base driving spring, and 20a denotes an end of the movable contact base driving spring 20 on the movable contact base side. Attach to 500. 2
Reference numeral 0b denotes an inner case side end of the movable contact point drive spring, which is attached to the inner case 2. The movable contact stand drive spring 20 is a spring such as a snap spring, and is curved so as to be concave toward the inner case 2 and convex toward the movable contact stand 500, and the movable contact 501 is connected to the fixed contact 401 and the movable contact 501. A torque (pull-back torque) for pressing in the contact direction is applied. 4
Reference numeral 00 denotes a fixed contact block which is inserted into and connected to the main circuit. 4
01 is a fixed contact formed on the fixed contact stand, 500 is a movable contact stand, 500a is a projection formed on the movable contact stand, 500b
Is a concave portion formed on the movable contact stand, and 501 is a movable contact formed on the movable contact stand. Reference numeral 600 denotes a rotational driving force transmission rod, which transmits the rotational driving force when the operation lever is operated to the movable contact base 500 to rotationally drive the movable contact base 500.
Reference numeral 600a denotes a convex portion formed on the rotary driving force transmission rod 600, and a convex portion 500a formed by forming the convex portion 600a on the movable contact stand.
, And the movable contact table 500 is rotationally driven. 800
Reference numeral denotes an opening / closing mechanism, which transmits a rotational driving force when an operation lever is operated to the movable contact base 500 via a rotational driving force transmission rod. Reference numeral 802 denotes a support for the movable contact block, which serves as a fulcrum when the movable contact block is rotationally driven.

Next, the opening operation of the circuit breaker will be described with reference to FIGS. When the circuit breaker is in the closed position shown in FIG. 1, the movable contact block drive spring 20 has one end 20a attached to the movable contact block 500 and the other end attached to the inner case 2.
Are curved so as to be concave toward the inner case 20 and convex toward the movable contact stand 500, and the movable contact 501 is fixed to the fixed contact 40.
A pull-back torque is applied to press one side. In addition,
At this time, the projection 600a formed on the transmission rod 600 is separated from the movable contact block.

As shown in FIG. 2, the open circuit operation of the circuit breaker operates the operation lever 801 to rotationally drive the rotational driving force transmission rod 600 via the opening / closing mechanism 800. The rotational driving force of the rotational driving force transmission bar 600 is transmitted to the convex portion 500a formed on the movable contact table 500 via the convex portion 600a formed on the surface of the rotational driving force transmitting bar 600, and the movable contact table 500 is rotated clockwise. Drive.

The movable contact point drive spring 20 is formed by a snap spring. For this reason, at the closed position of the circuit breaker, the unevenness of the movable contact stand drive spring 20 which is concave toward the inner case 2 and curved toward the movable contact stand 500 is reversed during opening. The driving force of the inverted movable contact point drive spring 20 is applied to move the movable contact 501 to the fixed contact 401.
The direction in which the movable contact 501 is pulled away from the fixed contact 401 (separation torque) is reversed from the torque in the direction in which the movable contact 501 is pressed to the side (retraction torque), and the opening speed of the movable contact base 500 is accelerated. FIG. 3 is a diagram showing an open circuit position. As shown in FIG.
Since the drive torque generated by 0 is reversed and the return torque does not act on the movable contact stand from the movable contact stand drive spring 20, no latch mechanism for latching the movable contact stand 400 to the open position is not required.

The support section 802 serves as a fulcrum when the movable contact point drive spring 20 drives the movable contact point table 500 to rotate. The provision of the support portion 802 facilitates the opening operation of the movable contact stand 500, and the rotation driving force transmission rod 6
From 00, the load applied to the movable contact point drive spring 20 can be suppressed to an appropriate value, and plastic deformation of the movable contact point drive spring 20 can be prevented.

The movable contact stand driving spring 20 is disposed behind the movable contact stand 500 and the support portion 802. With this arrangement, the movable contact drive spring 20 is not directly exposed to the heat of the arc generated between the movable contact 501 and the fixed contact 401 during the opening operation of the circuit breaker. Can be prevented.

When the circuit is opened by the electromagnetic repulsion from the closed position shown in FIG. 1, only the movable contact block 500 reaches the open position shown in FIG. 3 from the closed position shown in FIG.
In this case, the movable contact table 500 is a rotary driving force transmission rod 600.
The movable contact table 500 does not hit the rotation driving force transmission rod 600 during the opening operation of the movable contact table 500. Therefore, the opening operation speed of the movable contact base 500 does not decrease.

Further, since the concave portion 500b is provided on the outer periphery of the movable contact base 500, when the rotary driving power transmission bar 600 is in the open position shown in FIG. But never touch. Therefore, the movable contact base 500 is not pushed back to the closed position, and the movable contact base 500 can be prevented from being turned on again.

Further, the movable lever 5 is operated by operating the operating lever.
00 is returned to the closed position, the rotation driving force transmission rod 60
This is made possible by bringing the 0 convex portion into contact with the movable contact block 500 convex portion on the opposite side to that during the opening operation.

As described above, according to the present embodiment,
During the opening operation of the movable contact, a movable contact base drive spring having the characteristic that the torque acting on the movable contact changes from the withdrawal torque to the release torque is arranged, so that the opening operation speed is accelerated and the current interruption performance is improved. be able to. In addition, a latch mechanism for latching the movable contact block is not required, and the spring characteristics are less likely to deteriorate due to the arc, so that the reliability of the circuit breaker can be improved.

[0018]

As described above, according to the present invention, there is provided an open circuit breaker which prevents the opening speed of the movable contact block from being suppressed during the opening operation of the circuit breaker and improves the current breaking performance. can do.

[Brief description of the drawings]

FIG. 1 is a diagram showing a closed position of a circuit breaker according to an embodiment of the present invention.

FIG. 2 is a diagram showing a circuit breaker halfway open position according to the embodiment of the present invention.

FIG. 3 is a diagram showing a closed position of the circuit breaker according to the embodiment of the present invention.

FIG. 4 is a diagram showing a conventional circuit breaker.

[Explanation of symbols]

 2 Inner case 20 Movable contact stand drive spring 20a Movable contact stand drive spring end 20b Movable contact stand drive spring mounting board side end 400 Fixed contact stand 401 Fixed contact 500 Movable contact stand 500a Convex part 500b Concave part 501 Movable Contact 600 Rotational driving force transmission rod 600a Convex part 800 Opening / closing mechanism 801 Operating lever 802 Supporting part

Claims (4)

[Claims] 1. A fixed contact block having a fixed contact and a movable contact block having a movable contact, a rotational driving force transmitting mechanism for transmitting an operation force of an operating lever to rotationally drive the movable contact block, and the rotational drive An open / close mechanism for urging the movable contact block to a closed position where the movable contact contacts the fixed contact by a force transmission mechanism, and biasing the movable contact block to an open position where the movable contact does not contact the fixed contact; In the circuit breaker, the movable contact block includes a movable contact block drive spring, and the movable contact block drive spring biases the movable contact block toward the closed position side when the movable contact block is in the vicinity of the closed position. A circuit breaker for urging a movable contact block toward an open position when the contact block is near an open position. 2. The circuit breaker according to claim 1, wherein the movable contact point driving spring is a snap spring. 3. The rotation driving force transmission mechanism according to claim 1, further comprising: a transmission rod that transmits an operation force from an operation lever to a movable contact stand. A circuit breaker, wherein the movable contact block is urged to a closed position where the movable contact contacts the fixed contact and an open position where the movable contact does not contact the fixed contact via the formed convex portion. 4. The circuit according to claim 3, wherein the projection formed on the transmission rod is located at a position where the movable contact block does not come into contact with the movable contact block when the movable contact block is in an open position and a closed position. Circuit breaker.