JP3807042B2 - Earth leakage breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an earth leakage breaker, and more particularly to a configuration of a trip unit incorporated in the earth leakage breaker.
[0002]
[Prior art]
Trip coil that operates in response to signals from the operation handle, toggle contactor opening / closing mechanism, leakage detection unit, and leakage current detection unit as the earth leakage breaker described above (always retracts the armature with a permanent magnet, for example) A trip unit that combines an actuator connected to the armature of the trip coil and a trip lever that is driven by the actuator and incorporates a trip unit that operates when a leakage occurs. It is well known that the unit is configured to trip the main circuit contact to cut off the main circuit current.
[0003]
3 and 4 are basic configuration diagrams of such an earth leakage breaker. In each figure, 1 is a circuit breaker case, 2 is an opening / closing operation handle that slides around a support shaft 2a, 3 is a stationary contact, 4 Is a movable contact, 5 is a leakage detector with zero-phase CT, 6 is a trip coil of a trip unit, 7 is an actuator connected to the lower end of an armature (movable iron core) 6a of the trip coil 6, 8 is a trip lever, Is an earth leakage display button connected to the armature 6a of the trip coil 6 on the upper end side via a linkage 6b. Although not shown, a contact opening / closing mechanism constituted by a toggle link and an opening / closing drive spring is provided between the operation handle 2 and the movable contact 4, and a contact opening / closing mechanism is provided in the conventional earth leakage breaker. Separately, a reset lever constituted by a link mechanism is incorporated between the operation handle 2 and the trip lever 8.
[0004]
With such a configuration, the movable contact 4 comes into contact with the fixed contact 3 to be closed as indicated by the solid line in FIG. When the leakage detector 5 detects that a leakage has occurred in the main circuit, the trip coil 6 is operated by the output signal, and the armature 6a is attracted to the position shown in FIG. Pull 9 up. As a result, the trip lever 8 swings to the trip position, the latch (not shown) of the toggle-type contact opening / closing mechanism is removed and the tripping operation is performed, and the movable contact 4 is opened to the chain line position in FIG. Cut off circuit current. At the same time, the earth leakage display button 9 (which is normally retracted inside the case 1) protrudes outward from the case 1 to inform the outside that the circuit breaker has tripped.
[0005]
In addition, after the breaker has tripped, after repairing the cause of the leakage, when the breaker is turned on, first, when the operation handle 2 is turned from the trip position to the reset position, a reset lever (not shown) is driven. ) Pulls the actuator 7 of the trip unit downward to return it to the reset position, and then returns the operation handle 2 to the ON position, the contact opening / closing mechanism reverses and the movable contact 4 is closed (FIG. 3). (Solid line position).
[0006]
[Problems to be solved by the invention]
By the way, in the conventional configuration in which the operation handle 2 and the trip unit actuator 7 are linked by a link type reset lever and the trip unit is reset by the handle operation as in the prior art, as described below in terms of reliability. There is a problem.
[0007]
That is, in the configuration in which the reset lever is assembled by combining a plurality of link parts, the trip unit even if the operating handle 2 is turned to the reset position due to dimensional errors of each part, backlash between the parts in the assembly process, and play. However, it is easy to cause a problem in the reset operation in that the product does not return to the reset position correctly, and this is one factor that lowers the reliability of the product. In addition, the number of parts and assembly man-hours constituting the reset lever are increased, resulting in higher costs.
[0008]
The present invention has been made in view of the above points, and an object of the present invention is to provide an improved circuit breaker that solves the above-described problems and can reliably reset the trip unit with a simple configuration.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an actuator and a leakage indicator button are connected to an armature of a plunger type trip coil that operates in response to a signal from a leakage current detector, and a trip lever that is driven by the actuator is provided. An earth leakage circuit breaker that trips the main circuit contact through, and is configured to perform reset after the trip operation by operating the handle, provided with a reset arm that projects toward the actuator integrally with the operation handle, A self-holding leaf spring is attached to the trip coil along the actuator's up-and-down movement path, an engaging step is provided at a position facing the leaf spring of the actuator, and the leaf spring is engaged with the actuator. A convex part that contacts the stepped part and holds the actuator in the trip position. Provided, the actuator, pushing the engaging step portion in the trip time is engaging held to the trip position over the convex portion of the leaf spring, directly toward the reset position from the trip position via the reset arm on reset operation When the drive is pushed , the engaging stepped portion is moved over the convex portion of the leaf spring and reset to the reset position (claim 1).
[0011]
With the above configuration, when the operating handle is turned to the reset position after the tripping operation of the circuit breaker, the tip of the reset arm provided on the handle directly pushes the actuator of the trip unit to return to the reset position. Further, when the actuator returns to the reset position, the actuator is locked and held by the leaf spring member at the reset position.
[0012]
Moreover, since the reset arm is formed integrally with the operation handle, there is no backlash and play between the parts that would be a problem with the conventional reset lever configured with a link mechanism, and the actuator is reliably reset by giving a certain stroke. It can be handled with a simple structure.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on the examples of FIGS. In the drawings of the embodiment, the same members corresponding to those in FIGS. 3 and 4 are denoted by the same reference numerals.
That is, in this embodiment, the operation handle 2 made of a resin molded product is provided with an integrally formed reset arm 2b, and the tip of the reset arm 2b is connected to the armature 6a of the trip coil 6 in the case. It faces the upper surface of the shoulder portion 7a of the actuator 7 incorporated in the actuator.
[0014]
In addition, a self-holding leaf spring 10 having a convexly curved center is attached to the lower end side of the trip coil 6 along the upward / downward movement path of the actuator 7. The leaf spring 10 is held in contact with the engagement step portion 7b of the actuator 7 and held in this position even after the trip coil 6 is de-energized while the actuator 7 is pulled up to the trip position indicated by the solid line in the figure. To do.
[0015]
In this configuration, when resetting the tripping circuit breaker, when the operation handle 2 is turned to the reset position in FIG. 1, the reset arm 2b rotates counterclockwise around the support shaft 2a, and the trip unit The actuator 7 is driven down directly. As a result, the actuator 7 gets over the convex portion of the leaf spring 10 and moves from the solid line position in FIG. 2 to the chain line position to be reset.
[0016]
【The invention's effect】
As described above, according to the configuration of the present invention, the reset arm that protrudes toward the actuator is provided integrally with the operation handle, and the self-holding leaf spring is attached to the trip coil along the upward / downward movement path of the actuator. In addition, an engagement step portion is provided at a position facing the plate spring of the actuator, and a convex portion is provided on the plate spring to contact the engagement step portion of the actuator so as to lock and hold the actuator in a trip position. The actuator is driven and pushed directly from the trip position to the reset position via the reset arm during the reset operation , while the engaging stepped part gets over the convex part of the leaf spring during the trip. Once, configured so that the engaging step portion is reset to the reset position over the convex portion of the leaf spring Therefore, compared to the conventional trip lever driven by the operation handle with a link mechanism, there is no backlash and play between parts, and the trip unit can always be reset with a constant reset stroke. Will improve. Also, structurally, the number of parts and assembly man-hours are small compared with the conventional one, and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing a main internal structure of an earth leakage breaker according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a trip unit incorporated in FIG. 1. FIG. Basic configuration diagram [Fig. 4] Configuration diagram of trip unit in Fig. 3 [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit breaker case 2 Operation handle 2a Support shaft 2b Reset arm 4 Moving contact 5 Leakage detector 6 Trip coil 6a Armature 7 Actuator 8 Trip lever 10 Self-holding leaf spring

Claims (1)

An earth leakage circuit breaker that connects an actuator and an earth leakage display button to an armature of a plunger type trip coil that operates in response to a signal from an earth leakage current detector, and trips a main circuit contactor via a trip lever that is driven by the actuator. In the case where the reset after the trip operation is performed by the handle operation,
A reset arm that protrudes toward the actuator is provided integrally with the operation handle, and a self-holding leaf spring is attached to the trip coil along the up-and-down movement path of the actuator, and at a position facing the leaf spring of the actuator. An engagement step portion is provided, and a convex portion is provided on the leaf spring to contact the engagement step portion of the actuator to lock and hold the actuator in a trip position.
The actuator is driven and pushed directly from the trip position to the reset position via the reset arm during the reset operation , while the engaging stepped part gets over the convex part of the leaf spring during the trip. When this is done, the earth leakage circuit breaker is characterized in that the engagement step portion is moved over the convex portion of the leaf spring and reset to the reset position .

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