Mechanism coupling structure of molded case circuit breaker

A mechanism coupling structure of a molded-case circuit breaker according to an embodiment of the present disclosure including a shaft to one side of which a movable contactor is coupled, and on a part of which a rotating pinhole is formed in a penetrating manner; a base assembly into which the shaft is rotatably accommodated and coupled, a switch mechanism coupled to an upper portion of the base assembly and exposed with a first lower link and a second lower link at a lower side thereof, and a rotating pin coupled in a penetrating manner to the first lower link, second lower link and rotating pinhole may be provided therein, wherein the rotating pin has a protruding portion for release prevention at one end thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2016-0093670, filed on Jul. 22, 2016, the contents of which are all hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a mechanism coupling structure of a molded-case circuit breaker, and more particularly, to a mechanism coupling structure of a molded-case circuit breaker for preventing a lower link from being released from a rotating pin by an arc pressure generated at the time of breaking.

2. Description of the Related Art

In general, Molded-Case Circuit Breaker (MCCB) is an electric device for automatically breaking a circuit in the event of an electrical overload or short circuit to protect the circuit and a load thereof. The molded-case circuit breaker may largely include a terminal portion that can be connected to a power side or load side, a contact portion including a fixed contactor and a movable contactor brought into contact with or separated from the fixed contactor to connect or separate the circuit thereto or therefrom, a switch mechanism configured to move the movable contactor to provide power required for the switching of the circuit, a trip portion configured to sense an overcurrent or a short-circuit current at the switch mechanism and the power side to induce a tripping operation of the switch mechanism, and an extinguisher for extinguishing an arc generated when an abnormal current is interrupted.

FIG. 1illustrates a circuit breaker according to the prior art. Here, it is shown that molded-case circuit breaker is disassembled into a switch mechanism assembly1, a base assembly13, and a shaft assembly16in a state that an enclosure (case) is removed. Furthermore,FIG. 2illustrates a front view of a switch mechanism of a molded-case circuit breaker according to the prior art.

Here, the switch mechanism is constituted by coupling a pair of side plates11with a toggle link mechanism, a release mechanism, and the like. The toggle link mechanism includes a switch lever3connected to a handle2to rotate, an upper link6and a lower link4, connected to a link shaft5, and provided between a movable contactor7and a latch8. A release mechanism is connected to a lever-shaped latch8and a latch holder9to release the latch8in conjunction with the operation of an overcurrent releasing device (not shown). A main spring10is provided between the switch lever3and the link shaft5of the toggle link mechanism.

For a switching operation of the molded-case circuit breaker, when the handle2is moved to an OFF position in a closed (ON) state, the upper link6and lower link4of the toggle link mechanism receives an elastic force of the main spring10to rotate the shaft16while being bent in a “”-shape such that the movable contactor7is separated from the fixed contact (not shown) to open the circuit.

Furthermore, when an overcurrent flows during electrical conduction to operate an overcurrent release device (not shown), the release mechanism is activated by an output of the overcurrent release device to release the latch8held in the latch holder9. As a result, the latch8rotates in a counter-clockwise direction, and the switch mechanism8performs a trip operation to switch the movable contact7to interrupt the current.

The mechanism coupling of a molded-case circuit breaker according to the prior art may couple the lower link4and the shaft assembly16of the mechanism with a single rotating pin12formed in a straight line shape. In other words, the operation of the lower link4rotates a shaft17by a rotating pinhole18formed on the shaft17and coupled in a penetrating manner to a pinhole4aof the lower link4. Here, the shaft assembly16is inserted and coupled into an accommodation space formed within the base assembly13. Furthermore, the base assembly13is provided with a through hole14formed in an arc shape to form a space in which the rotating pin12can operate.

FIG. 3is a side view in which a mechanism of a molded-case circuit breaker according to the related art is in a coupled state. It illustrates an ON state.FIG. 4is a perspective view illustrating the lower link.

In an electrical conduction (ON) state as illustrated inFIG. 3, the lower link4moves downward to completely cover the through hole14of the base assembly13. However, in the coupled state of such a mechanism, an internal pressure generated at the time of interruption may leak along a fine gap between the components to act on the lower link4. Accordingly, the leaked pressure may act on the lower link4coupled to the rotating pin12with a force of pushing the lower link4in an outward direction, thereby causing a problem of releasing the lower link4from the rotating pin12.

SUMMARY OF THE INVENTION

The present invention is contrived to solve the foregoing problem, and an aspect of the present invention is to provide a mechanism coupling structure of a molded-case circuit breaker for preventing a lower link from being released from a rotating pin by an arc pressure generated at the time of breaking.

A mechanism coupling structure of a molded-case circuit breaker according to an embodiment of the present disclosure including a shaft to one side of which a movable contactor is coupled, and on a part of which a rotating pinhole is formed in a penetrating manner; a base assembly into which the shaft is rotatably accommodated and coupled, a switch mechanism coupled to an upper portion of the base assembly and exposed with a first lower link and a second lower link at a lower side thereof, and a rotating pin coupled in a penetrating manner to the first lower link, second lower link and rotating pinhole may be provided therein, wherein the rotating pin has a protruding portion for release prevention at one end thereof.

Here, the rotating pin may include a first rotating pin having a first protruding portion and a second rotating pin having a second protruding portion.

Furthermore, the first rotating pin and second rotating pin may be symmetrically provided in such a manner that the first protruding portion and second protruding portion face outward.

Furthermore, the first protruding portion and second protruding portion may be brought into contact with the first lower link and second lower link.

Furthermore, an arc-shaped pinhole may be formed on the base assembly to expose the rotating pinhole when the shaft rotates, and a discharge groove configured to open a part of the pinhole may be formed at a lower portion of the first lower link and second lower link to discharge an arc pressure generated at the time of interruption to an outside thereof.

Furthermore, the discharge groove may be formed by cutting a part of the first lower link and second lower link.

Furthermore, a screw groove and a screw portion may be formed at body end portions of the first rotating pin and second rotating pin, respectively, to allow the first rotating pin and second rotating pin to be screw-coupled to each other.

In addition, threads may be formed on rotating pin coupling holes of the first lower link and second lower link, and the first rotating pin and second rotating pin may be configured with screws.

According to a mechanism coupling structure of a molded-case circuit breaker in accordance with an embodiment of the present disclosure, a part of an arc pressure generated at the time of interruption may be discharged through a discharge groove on a lower link, thereby having an effect of reducing a pressure acting on the lower link.

Furthermore, a rotating pin may have a protruding portion, thereby having an effect of preventing the rotating pin from being released from a lower link even when receiving a force due to an arc pressure.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings to such an extent that the present invention can be easily implemented by a person having ordinary skill in the art to which the present invention pertains, but it does not mean that the technical concept and scope of the present invention are limited due to this.

FIG. 5is a perspective view illustrating a mechanism coupling structure of a molded-case circuit breaker according to an embodiment of the present disclosure, andFIG. 6is a front view illustrating a switch mechanism of a molded-case circuit breaker according to an embodiment of the present disclosure, andFIG. 7is a side view in which a mechanism of a molded-case circuit breaker according to an embodiment of the present disclosure is in a coupled state, andFIGS. 8 and 9are perspective views illustrating a rotating pin and a lower link applied to a mechanism of a molded-case circuit breaker according to an embodiment of the present disclosure. A mechanism coupling structure of a molded-case circuit breaker according to each embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

A mechanism coupling structure of a molded-case circuit breaker according to an embodiment of the present disclosure may include a shaft21to one side of which a movable contactor25is coupled, and on a part of which a rotating pinhole22is formed in a penetrating manner; a base assembly30into which the shaft21is rotatably accommodated and coupled, a switch mechanism50coupled to an upper portion of the base assembly30and exposed with a first lower link40and a second lower link45at a lower side thereof, and a rotating pin60,65coupled in a penetrating manner to the first lower link40, second lower link45and rotating pinhole22, wherein the rotating pin60,65has a protruding portion61,66for release prevention at one end thereof.

FIGS. 5 and 7illustrate an exploded perspective view and a coupled front view of a mechanism of a molded-case circuit breaker according to an embodiment of the present disclosure, andFIG. 6illustrates a front view of a switch mechanism. The mechanism of the molded-case circuit breaker may largely include a shaft assembly20including a movable contactor25and a shaft21to which the movable contactor25is coupled at one side thereof, a base assembly30provided with a contact portion, an extinguisher and a terminal portion including a fixed contactor (not shown) and a movable contactor25, and a switch mechanism50configured to rotate the shaft21. Here, an entire enclosure of the molded-case circuit breaker is not illustrated.

The base assembly30accommodates the movable contactor25and fixed contactor to provide a space for accommodating the contact portion to perform breaking of an electrical circuit. The base assembly30may be configured with a pair of molds divided into the left and the right. The terminal portions are provided at both end portions of the base assembly30in a length direction. Here, a power side (or load side) terminal portion31is provided at one end thereof, and a coupling portion23coupled to a load side (or power side) terminal portion (not shown) is provided at the other end thereof.

Coupling holes33,34to which the switch mechanism50can be coupled are formed in a penetrating manner on a part of the base assembly30. Couplings pins38,39are coupled in a penetrating manner to the coupling holes33,34, respectively.

A mounting portion35on which the switch mechanism50can be mounted may be formed in a step or a groove shape on both sides of the base assembly30in a width direction. The coupling holes33,34may be formed on a part of the mounting portion35. A link operation portion36may be formed in a step or groove shape on a part of the mounting part35to operate the first lower link40and second lower link45.

A pinhole37that is a space in which the rotating pins60,65which will be described later can be exposed and operated is formed on both sides of the base assembly30. The pinhole37may be provided in a part of the link operation portion36. The pinhole37may be formed in an arc shape. The pinhole37may be formed to be larger than an operating space of the rotating pins60,65.

The switch mechanism50may include a pair of side plates51fixed to the base assembly30, a switch lever52rotatably provided on the side plates51, a handle53coupled to an upper portion of the switch lever52to transfer a user's power, a main spring54elastically operated by the rotation of the handle53to transfer power to a link shaft55, and a first lower link40and a second lower link45upper ends of which are coupled to the link shaft55to move.

Side plate coupling holes51a,51bare formed on the side plates51, and side plates51are inserted and coupled into the base assembly30to allow the positions of the side plate coupling holes51a,51bto correspond to the coupling holes33,34of the base assembly30, and coupling is fixed and maintained by the coupling pins38,39passing through the side plate coupling holes51a,51band coupling holes33,34. Here, the side plates51is inserted to surround the mounting portion35, and the first lower link40and second lower link45are placed at a position of the pinhole37on the link operation portion36.

The shaft assembly20is accommodated into the base assembly30. The base assembly30may include a shaft21, a movable contactor25coupled to one side of the shaft21, and a terminal coupling portion23coupled to the other side of the shaft21. The terminal coupling portion23is fixed to the other end of the base assembly30, and the shaft21is rotatably provided to rotate the movable contactor25along with the shaft21when turned on or off.

A rotating pinhole22into which the rotating pin60,65can be inserted and coupled is formed in a penetrating manner on the shaft21. The shaft21receives a force of the first lower link40and second lower link45by the rotating pin60,65coupled to the rotating pinhole22to move.

The rotating pin60,65may be configured with a first rotating pin60and a second rotating pin65. The first rotating pin60and second rotating pin65may be formed in the same shape. The first rotating pin60and second rotating pin65are inserted and coupled into the first lower link40and second lower link45, respectively.

A first protruding portion61and a second protruding portion66are formed at an outside of the first rotating pin60and second rotating pin65, respectively. The first protruding portion61and second protruding portion66may be formed to have a larger diameter than a body portion of the first rotating pin60and second rotating pin65. An inner surface61aof the first protruding portion61and an inner surface66aof the second protruding portion66are brought into contact with the first lower link40and second lower link45.

Referring toFIG. 6, the first rotating pin60and second rotating pin65are symmetrically provided to each other in such a manner that end portions of the body portion are brought into contact with each other (the first protruding portion61and second protruding portion66face outward. Accordingly, the first rotating pin60and second rotating pin65are brought into contact with the first lower link40and second lower link45to prevent movement so as not to be pulled inward as well as not to be released from the link40and second lower link45.

Referring toFIG. 9, the first lower link40and second lower link45may be formed in an arc shape. The link shaft coupling holes41,46may be formed at upper ends of the first lower link40and second lower link45, respectively, and the rotating pin coupling holes42,47at lower ends of the first lower link40and second lower link45, respectively.

A first discharge groove43and a second discharge groove48are formed on a part of the first lower link40and second lower link45, respectively. The first discharge groove43and second discharge groove48may be formed by cutting a part of a rear portion on which the first lower link40and second lower link45are formed in a bent shape. Here, inner surfaces of the first discharge groove43and second discharge groove48may be formed into a convex curved surface.

Referring toFIG. 7, though a part of the pinhole37is open by the first discharge groove43and second discharge groove48of the first lower link40and second lower link45in an ON state of the circuit breaker to form an exhaust space (B), and most of an arc pressure generated at the time of interruption is discharged through an arc extinguisher and an exhaust portion (A), a part of the residual pressure may be also discharged through the exhaust space (B), thereby reducing a pressure receiving at the first lower link40and second lower link45due to an arc impact.

According to a mechanism coupling structure of a molded-case circuit breaker in accordance with an embodiment of the present disclosure, a part of an arc pressure generated at the time of interruption may be discharged through a discharge groove on a lower link, thereby having an effect of reducing a pressure acting on the lower link. Furthermore, a rotating pin may have a protruding portion, thereby having an effect of preventing the rotating pin from being released from a lower link even when receiving a force due to an arc pressure.

FIGS. 10A and 10Billustrate a mechanism coupling structure of a molded-case circuit breaker according to another embodiment of the present invention. Here, only a portion to which the lower link and the rotating pin are coupled is illustrated.

According to the present embodiment illustrated inFIG. 10A, it is illustrated that a screw groove62is formed in a body end portion of the first rotating pin60, and a screw portion67is formed in the body end portion of the second rotating pin6to allow the first rotating pin60and second rotating pin65to be screw-coupled to each other.

According to the present embodiment illustrated inFIG. 10B, it is illustrated that threads are formed on rotating pin coupling holes42a,47aof the first lower link40and second lower link45, and the first rotating pin60aand second rotating pin65aare configured with screws.

According to the embodiments illustrated inFIGS. 10A and 10B, the first rotating pin and second rotating pin may be coupled by screw-coupling, and thus have an excellent coupling force, thereby more effectively preventing the lower link from being released from the rotating pin.

It will be apparent to those skilled in this art that various changes and modifications may be made thereto without departing from the gist of the present invention. Accordingly, it should be noted that the embodiments disclosed in the present invention are only illustrative and not limitative to the concept of the present invention, and the scope of the concept of the invention is not limited by those embodiments. The scope protected by the present invention should be construed by the accompanying claims, and all the concept within the equivalent scope of the invention should be construed to be included in the scope of the right of the present invention.