JPH0824021B2 - Circuit breaker switching mechanism - Google Patents

Description

The present invention relates to an opening / closing mechanism for a circuit breaker, and more particularly to a tripping mechanism.

[Conventional technology]

FIG. 3 is a side sectional view of the circuit breaker disclosed in, for example, Japanese Utility Model Laid-Open No. 61-120159, FIG. 4 is an element configuration diagram of the opening / closing mechanism in an ON state, and FIG. It is an element block diagram of a state.

In the figure, (1) is a housing as a base forming an outer shell of a circuit breaker, (2) is a fixed contactor having a fixed contact (2a) attached to the housing (1), and (3) is an axis ( 4) A movable contact (3a) that is rotatably supported by 4) and has one end facing the fixed contact (2a).
And a movable contactor having an inclined portion (3b) which engages with an operation link (8) described later at the other end, and (5) always moves the movable contactor (3) from the fixed contactor (2). A spring for urging the handle to open, (6) a handle, (1a) a stopper that prevents the handle (6) from overclockwise rotating,
(7) is a handle spring for urging the handle (6) in a counterclockwise direction (off direction), and (8) is an operation link in which a round bar is formed in a U shape, and one end of which is engaged with the handle (6). The other end engages with the inclined portion (3b). (9) is a rotatable roller fitted to the other end of the operation link (8), and (10) is an L-shaped member that is supported by the shaft (4) and locks the roller (9) at one end. A locking piece (12) having a bent portion (10a) formed and biased counterclockwise by a tension spring (11).
Is a bimetal which is heated and curved to the right in response to an applied current, (13) is an electromagnet, (13a) is a plunger which is a moving member driven by an electromagnetic force applied to the electromagnet (13),
(10b) is a trigger piece B that receives the first force in the direction of releasing the lock between the roller (9) and the downward bending portion (10a) by the pressing force due to the bending of the bimetal (12), and (10c) is the roller (9). )
And the trigger piece M which receives the second force for releasing the locking of the bent portion (10a), that is, the pushing force of the plunger (13a).

The operation of the opening / closing mechanism configured as described above will be described. First, when the handle (6) is rotated clockwise from the off state in FIG. 5, the engaging portion between the handle (6) and the operation link (8) moves to the upper left. As a result, the roller (9) side of the operation link (8) is bent via the roller (9) to the bent portion (10).
Since the upward movement is blocked by a), the movable contact (3) is rotated counterclockwise by pushing the inclined part (3b) to the left, and the movable contact (3a) is fixed to the fixed contact (2a). Contact. When the handle (6) is further rotated clockwise,
The engaging portion between the operation link (8) and the handle (6) crosses the dead point and comes into contact with the stopper (1a). Most of the urging force of the spring (5) is received by the stopper (1a) via the inclined portion (3b) and the operation link (8), and the operation link on the roller (9) side generated at the inclined portion (3b). (8)
The upward component of force is applied to the bending part (10
a) is locked and the open / close mechanism is kept on. This state is shown in FIG.

From this state, the bimetal (12) bends due to overcurrent, and when the trigger piece B (10a) is pushed, the locking piece (10)
Rotates clockwise around the shaft (4),
Unlock the roller (9) in a). As a result, the roller (9) side of the operation link (8) is free to move upward, and the movable contact (3) tilts the roller (9) side of the operation link (8) by the biasing force of the spring (5). The part (3b) pushes it up and turns it clockwise to open and close the movable contact (3a) and the fixed contact (2a). Operation link (8)
Since the roller (9) side of is pushed up,
Since the engaging portion between the handle (6) and the operation link (8) is below the dead point, the handle (6) rotates counterclockwise by the urging force of the handle spring (7) to move the operation link (8). Although pulled to the right, the roller (9) comes into contact with the tip of the bent portion (10a) and is stopped midway, so the handle (6) is held at the trip display position without returning to the off position.

Further, at the time of instantaneous trip of a short circuit current or the like, the plunger (13a) is driven by the attractive force of the electromagnet (13) and the trigger piece M (10c) is pushed to rotate the locking piece (10) clockwise. The interruption operation is performed by the same operation as in the above-mentioned explanatory diagram. Generally, the instantaneous trip operation is performed within a few milliseconds to a few tens of milliseconds, and the operation with the same current value can be said to be a circuit breaker with better performance if the breaking operation can be performed in a short time.

[Problems to be Solved by the Invention]

Bending part (10a) of the opening / closing mechanism configured as described above
Since the locking piece (10) is formed by bending a part of it, the position where it comes into contact with the roller (9) differs each time due to variations in the corner radius dimension, burrs during shearing, and the inclination of the mechanism. That is, there is a problem in that the trip time varies due to the variation in the trip dimension.

The present invention has been made to solve the above problems, and an object thereof is to obtain an opening / closing mechanism of a circuit breaker in which variations in hanging dimensions of a roller and a bent portion are eliminated and a tripping operation time is stabilized. .

[Means for solving the problem]

In the opening / closing mechanism according to the present invention, a protrusion that comes into contact with the roller is provided on the linear portion of the locking piece.

[Action]

In the circuit breaker opening / closing mechanism according to the present invention, the roller is locked at the two points of the protrusion and the bent portion provided on the locking piece, and the linear portion and the roller do not come into linear contact with each other. The influence of the variation in the machining of is reduced and the dimensional variation of the engagement state of the roller is reduced.

〔Example〕

FIG. 1 is an element configuration diagram of an opening / closing mechanism showing an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof. In the figure,
(2) to (9) and (11) to (13) are the same as those described in the conventional example. (14) is an elongated hole (14e) described later
A bent portion (14a) which is rotatably supported by a shaft (4) through a shaft and movably in the longitudinal direction of the elongated hole (14e) and which is bent into an L-shape to lock the roller (9) at one end. Have
A locking piece biased counterclockwise by the tension spring (11),
Reference numeral (14d) is a projection provided on the straight portion of the locking piece (14), and the roller (9) is bent at the bent portion (14a) in the closed state.
And the protrusion (14d) are in contact with each other at two points. (14
e) is an elongated hole for pivotally supporting the bent piece (14),
It is long in the direction to receive the force from the plunger (13a). (14b) is a trigger piece B that receives a force in the direction of releasing the engagement between the roller (9) and the bent portion (14a) by the pushing force due to the bending of the bimetal (12), and the (14c) is the pushing piece of the plunger (13a). Roller (9) and folding part (1
4a) Trigger piece M that receives the force to release the lock, (15)
Is a frame that supports the opening / closing mechanism.

In the opening / closing mechanism of the above mechanism, the closing operation is similar to that of the conventional example. At the time of loading, the elongated hole (14e) is placed in the loading state at a position leaving a gap on the right side of the shaft (4), that is, on the side of the plunger (13a) by the urging force of the pulling spring (11).
In the closed state, the roller (9) is attached to the inclined portion (3b) of the movable contactor (3) at two points, that is, the bent portion (14a) of the locking piece (14) and the protrusion (14d) provided on the straight portion. Since it is locked, the roller (9) does not come into linear contact with the straight part of the locking piece (14), and the burrs at the time of shearing the locking piece (14) and the bending of the bent part (14a) It is possible to stabilize the locked state between the roller (9) and the locking piece (14) by eliminating the influence of variations in angle.

The tripping operation due to the bending of the bimetal (12) when overcurrent is applied, the trigger piece B (14b) and the bent portion (14a) are almost at the same height, and the locking piece (14) is inserted through the long hole (14e). Even if it is supported by the shaft (4), it is not affected and the same breaking operation as that of the conventional example is performed.

When the plunger (13a) pushes the trigger piece M (14c) during an instantaneous trip operation due to a short circuit current, etc., the shaft (4) slides in the long hole (14e) and the locking piece (14) is a roller. (9)
With the fulcrum as the fulcrum, the right end of the long hole (14e) moves until it contacts the shaft (4), and then the locking piece (14) rotates around the shaft (4) as a fulcrum to unlock the roller (9). To do. At this time, the force to move the trigger piece M (14c) in the trip direction is the long hole (14
Since the roller (9) serves as a fulcrum during the initial movement until the right side of e) hits the shaft (4), a very small force is required.

Therefore, the plunger (13) of the electromagnet (13) described above is
In the drive of a), the trip mechanism has a characteristic that the force is weak at the time of starting and the suction force increases after being sucked to some extent. As a result, the pushing force (energy) of the plunger (13a) against the trigger piece M (14c) can be reduced, the mass of the plunger (13a) can be reduced, and the instantaneous trip time can be shortened.

Although the above embodiment has been described with respect to the thermal electromagnetic circuit breaker, the same effect can be obtained even if this configuration is used for the completely electromagnetic circuit breaker.

〔The invention's effect〕

As described above, according to the present invention, since the linear portion of the locking piece is provided with the projection that comes into contact with the roller, the dimensional variation in the locked state of the roller is reduced, and the tripping operation time can be stabilized.

[Brief description of drawings]

FIG. 1 is an element configuration diagram of a switchgear of a circuit breaker showing an embodiment of the present invention, FIG. 2 is an exploded perspective view of a switchgear of an embodiment, and FIG. 3 is a circuit breaker showing a conventional example. FIG. 4 is a side sectional view, FIG. 4 is an element configuration diagram showing an ON state of a conventional opening / closing mechanism,
FIG. 5 is an element configuration diagram showing an off state of a conventional opening / closing mechanism. In the figure, (3) is a movable contact, (3b) is an inclined part,
(8) is an operation link, (9) is a roller, (14) is a locking piece, (14a) is a bent portion, (14c) is a trigger piece M,
(14d) is a protrusion and (14e) is an elongated hole. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A fixed contact, which has a fixed contact and is fixed to a base, a movable contact, and an inclined portion provided at a predetermined distance from the movable contact. Between the movable contact, which is rotatably supported by the base and is always biased in a predetermined rotational direction so that the movable contact is separated from the fixed contact, a handle supported by the base, and one end. A roller rotatably provided at the other end and an operation link rotatably connected to the handle at the other end; a bent portion bent from a straight line portion into an L-shape; and a protrusion protruding from the straight line portion. A locking piece rotatably supported on the base, a pulling spring for biasing the locking piece in a direction opposite to the predetermined rotation direction, and an electromagnet to drive the locking piece in the predetermined rotation direction. Movement arranged so that it can be rotated to A material, and the inclined portion and the roller are locked by the bent portion and the protrusion, and the locking is released by rotating the locking piece in the predetermined rotation direction by the moving member. A circuit breaker switching mechanism characterized by the above.