JP2545876Y2 - Circuit breaker - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is to perform current limiting by separating the mover by the electromagnetic repulsion force by the large current supply, regardless of the shut-off operation by the automatic trip device. And a circuit breaker.

[Conventional technology]

A conventional circuit breaker of this type will be described with reference to FIGS. 2 is a longitudinal side view, FIG. 3 is an enlarged view of a second main part showing an ON state, FIG. 4 is the same view as FIG. 3 showing an OFF state, FIG. The same figure,
FIG. 6 is the same as FIG. 3 showing the rebound state, and FIG.
It is a partial longitudinal enlarged view of the figure. In the figure, (1) is a circuit breaker case, which is composed of a base (1a) and a cover (1b). (2) a fixed conductor on the power supply side fixed to the base (1a), (3) a fixed contact fixed to the fixed conductor (2),
(4) is an automatic trip device, (5) is a fixed conductor on the load side connected to the automatic trip device (4), (6) is a movable contact, and (7) is a mover to which the movable contact (6) is fixed. ,
(8) a flexible conductor for connecting the mover (7) to the automatic trip device (4) via the connection conductor (9); (10)
Is a contact arm for holding the mover (7), and a first contact arm (10
a) and a mover (7) are formed separately into a second contact arm (10b) rotatably supported by a first pin (11). (12) is a support shaft of the contact arm (10), and the first contact arm (10a) and the second contact arm (10b) are rotatably supported respectively. (13) is the first contact arm of each pole (10a)
(14) is a guide hole provided in the first contact arm (10a) and extending in the opening / closing direction;
5) is a slot provided in the second contact arm (10b),
It extends in a direction crossing the guide hole (14). (16) is a second engagement that straddles the guide hole (14) and the long hole (15).
Pin (17) is the first pin (11) and the second pin (16)
The second pin (16) is urged by a tension spring provided between the first pin and the second pin. (18) is a contact pressure spring provided between the mover (7) and the second contact arm (10b), (19) is an operation handle of a circuit breaker, (20) is an opening / closing mechanism of the circuit breaker, and a cradle. (20a), upper link (20b), lower link (20c) and the like. (21) is a stopper pin provided on the cradle (20a), (22) is a connecting pin for connecting the lower link (20c) to the first contact arm (10a),
(23) is an arc-extinguishing chamber.

Next, the operation will be described. In the ON state shown in FIGS. 2 and 3, the power-supply-side fixed conductor (2) → fixed contact (3) → movable contact (6) → movable element (7) → flexible conductor (8) → connection conductor (9) ) → Automatic trip device (4) → Current flows in the direction of load-side fixed conductor (5). When the operating handle (19) is turned off (in the direction of arrow (24) in FIG. 3), the contact arm (10) is lifted by the opening / closing mechanism (20), and the movable contact (6) is moved together with the movable element (7). As shown in FIG. 4, it is separated from the fixed contact (3). At this time, since the second pin (16) is fitted in the concave portion (14a) of the guide hole (14) by the pull spring (17), the second contact arm (10b) is connected to the first contact arm (10a). ) And is lifted by the opening / closing mechanism (20), and stops by colliding with the stopper pin (21) with the support shaft (12) as a fulcrum.

When an overload current flows in the ON state shown in FIGS. 2 and 3, the automatic trip device (4) operates and the cradle (20a) rotates in the direction of the arrow (25) in FIG.
The operation of the opening / closing mechanism (20) allows the contact arm (1
0) is lifted and the movable contact (6) is opened as shown in FIG. 5 to cut off the overload current. This is a so-called trip state. At this time, similarly to the off state in FIG. 4, the second pin (16) is moved by the pulling spring (17) into the guide hole (1).
4), the second contact arm (10b) is lifted by the opening / closing mechanism (20) integrally with the first contact arm (10a), and the second contact arm (10b) is lifted by the opening / closing mechanism (20).
With 2) as a fulcrum, it collides with the stopper pin (21) and stops.

When a large current such as a short-circuit current flows in the ON state shown in FIGS. 2 and 3, the fixed conductor (2) is acted upon by the action of electromagnetic force generated between the fixed conductor (2) and the mover (7). The mover (7) repels and separates as shown in FIG.
At this time, since the operation of the first contact arm (10a) operated by the opening / closing mechanism (20) that operates following the operation of the automatic trip device (4) is delayed in time, the second contact arm (10b) ) Overcomes the urging force of the tension spring (17), removes the second pin (16) from the recess (14a), and moves the guide pin (14) in the guide hole (14), thereby using the support shaft (12) as a fulcrum. Opening in the direction of arrow (26), the second pin (16) collides with the end (14b) of the guide hole (14) and stops. This repulsive movement is faster than the operation of the opening / closing mechanism (20) to which the mover (7) is connected via the contact arm (10), thereby enhancing the current limiting effect.
The first contact arm (10a) is tripped and lifted by the automatic tripping device (4) following the repulsion state shown in FIG. 6, so that the second pin (16) is again inserted into the guide hole (14). It is fitted into the concave portion (14a) and the trip state shown in FIG. This operation is called contact arm (10)
It is called reset. At this time, the second pin (16) is urged by the tension spring (17), and is brought into contact with the pin sliding surface (14c) of the guide hole (14) by its contact surface (16a). Reciprocate once on the pin sliding surface (15a) of (15).

[Problems to be solved by the invention]

In the conventional circuit breaker as described above, the first contact arm (10a), the second contact arm (10b), and the second pin (16) are plated with zinc for the purpose of rust prevention. I have. However, since the zinc-plated zinc has a low melting temperature, a melt such as copper and a silver alloy caused by an arc at the time of cutoff causes the pin sliding surface (14c) of the guide hole (14) to be broken.
Adhering to the pin sliding surface (15a) of the long hole (15) and the contact surface (16a) of the second pin (16), the movement of the second pin (16) is deteriorated, and stable blocking performance is achieved. There was a problem that it could not be obtained.

This invention has been made to solve such a problem, and by preventing the arc melt from adhering to both the sliding surfaces of the guide hole and the long hole and the contact surface of the second pin. It is an object of the present invention to obtain a circuit breaker that prevents the deterioration of the movement of the second pin and obtains a stable breaking performance.

[Means for solving the problem]

The circuit breaker according to the present invention includes a pin sliding surface of at least an L-shaped guide hole of the first contact arm, a pin sliding surface of at least a long hole of the second contact arm, and at least the two pins of the second pin. This is a surface treatment for forming a surface on which the arc melt does not adhere to the contact surface that contacts the impulsive surface.

[Action]

In this invention, a surface treatment is performed to form a surface on which the arc melt does not adhere to both the sliding surfaces of the L-shaped guide hole and the long hole and the contact surface of the second pin. In addition, the arc melt at the time of interruption is unlikely to adhere to the sliding surfaces of both pins and the contact surface, and the movement of the second pin is not hindered.

[Example of the invention]

One embodiment of the present invention will be described with reference to FIG. First
The figure is a partially enlarged longitudinal sectional view similar to that of FIG. In the figure, (10A) is a first contact arm whose surface is plated with metal such as nickel plating whose melting point is higher than copper, and (10B) is a first contact arm whose surface is plated with metal such as nickel plating whose melting point is higher than copper. The second contact arm, (16A), is a second pin whose surface is plated with metal such as nickel plating whose melting point is higher than copper.

When the first contact arm (10A), the second contact arm (10B), and the second pin (16A) whose surfaces are plated with metal having a melting point higher than that of copper are used,
The pin sliding surface (14c) of the L-shaped guide hole (14) of the contact arm (10A), the pin sliding surface (15a) of the long hole (15) of the second contact arm (10B), and the second pin Since the surface treatment for forming a surface where the arc melt does not adhere to the contact surface (16a) of (16A) is performed, L
Guide pin (14) and slot (15) pin sliding surfaces (14
c), (15a) and the contact surface (16a) of the second pin (16A) do not easily adhere to the arc melt at the time of interruption, and the second pin (16a)
The movement of A) is not interrupted.

In the above embodiment, the first and second contact arms (10
A), (10B) and the second pin (16A) are shown to be plated with metal having a melting point higher than that of copper, but the first and second contact arms (10A), (10B) and the second pin (16B) (16
A) may be iron or stainless steel, and a nitriding treatment may be performed on the surface thereof.

In each of the above embodiments, the first and second contact arms (10
A), (10B) and the entire surface of the second pin (16A) are shown, but the first contactor arm (10
A) At least the pin sliding movement (14) of the L-shaped guide hole (14)
c) The melting point of each of the pin sliding surface (15a) of at least the elongated hole (15) of the second contact arm (10B) and at least the contact surface (16a) of the second pin (16A) is higher than that of copper. Similar effects can be obtained by performing metal plating or nitriding.

[Effect of the invention]

As described above, according to the present invention, both the L-shaped guide hole and the elongated pin sliding surfaces disposed near the contact point and the second pin sliding surface.
A simple means of performing a surface treatment to form a surface on which the arc melt does not adhere to the contact surface of the pin, so that the arc melt at the time of interruption is applied to both pin sliding surfaces and the contact surface. Since the adhesion can be prevented, the movement of the second pin is not deteriorated, and there is an effect that the blocking performance can be stabilized at low cost. By the way, in the above configuration, an L-shaped guide hole provided in the first contact arm, a long hole provided in the second contact arm and extending in a direction intersecting with the L-shaped guide hole, and both of them. Due to the complicated shapes of sliding and impinging action of the second pins that are commonly engaged across the holes, and by the formation of a complex synthetic guide hole in which the two contact arms overlap and slide together. If even a small amount of the arc melt adheres to the sliding surfaces of the three members, high-precision breaking performance cannot be expected. In view of this importance, performing surface treatment on each of the above surfaces is particularly effective for this type of circuit breaker.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal enlarged view showing an embodiment of the present invention, FIG. 2 is a longitudinal side view showing a conventional one, FIG. 3 is an enlarged view of a main part of FIG. 2 showing an ON state, and FIG. Is the same view as FIG. 3 showing the off state, FIG. 5 is the same view as FIG. 3 showing the trip state, FIG. 6 is the same view as FIG. 3 showing the rebound state, and FIG. It is a partial longitudinal enlarged view. In the figure, (4) is an automatic trip device, (7) is a mover, (10) is a contact arm, (10A) is a first contact arm, (10B) is a second contact arm,
(11) is the first pin, (12) is the support shaft, (14) is the guide hole, (14a) is the end, (14c) is the pin sliding surface, (15) is the long hole, and (15a) is Pin sliding surface, (16A) is the second pin, (16A)
a) is a contact surface, and (17) is a spring. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shiro Murata 1-8 Midoricho, Fukuyama-shi, Hiroshima Mitsubishi Electric Corporation Fukuyama Works (56) References JP-A-59-43856 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A movable element to which a pair of contacts is fixed and a movable element are separated by an electromagnetic repulsion force by applying a large current to a fixed conductor irrespective of a shut-off operation by an automatic trip device. The contact arm holding the mover is divided into a first contact arm and a second contact arm which are rotatably supported with each other, and the opening / closing mechanism is opened. An L-shaped guide hole provided in the first contact arm connected to the first contact arm and extending in the opening and closing direction; and the L-shaped guide provided in the second contact arm in which the movable element is supported by a first pin. An elongated hole extending in a direction intersecting the hole, a second pin that straddles the elongated hole and the L-shaped guide hole and is disposed near the contact point,
A circuit breaker having a spring for urging the pins of
At least a pin sliding surface of the L-shaped guide hole of the first contact arm, at least a pin sliding surface of the long hole of the second contact arm, and at least the two pin sliding surfaces of the second pin. A circuit breaker, wherein a contact surface to be contacted is subjected to a surface treatment for preventing adhesion of an arc melt generated at the time of interruption.