JP4419723B2 - Circuit breaker switching mechanism - Google Patents

Description

  The present invention relates to an opening / closing mechanism provided in a circuit breaker for wiring breakers, earth leakage breakers and the like.

FIG. 2 shows the structure of a conventional circuit breaker switching mechanism described above (see, for example, Patent Document 1 and Patent Document 2). In the figure, 1 is a circuit breaker case (resin mold case), 2 is a stationary contact, 3 is a movable contact, 4 is a rotary contact holder holding the movable contact 3, and 4a is an opening / closing shaft thereof. (Support shaft) 5 is an opening / closing operation handle (rocker-type handle) provided on the upper surface side of the case 1, 6 is a handle lever connected to the handle 5, 7 is an overcurrent tripping device (not shown) via a latch receiver The latches 8 are linked to each other, 8 is a toggle link composed of the first link 9 and the second link 10, and 11 is an opening / closing spring (tensile coil spring). These members are assembled to the frame 12 to constitute an opening / closing mechanism.
Here, one end of the first link 9 and the second link 10 of the toggle link 8 is interconnected via a toggle shaft 13 serving as a driving node, and the other end of the first link 9 is latched (always illustrated). The other end of the second link 10 is connected to a crankshaft 15 provided on the contact holder, This constitutes a four-bar link booster mechanism. The open / close spring (tensile coil spring) 11 is stretched by hooking hooks at both ends thereof on the toggle shaft 13 and the top of the handle lever 6.

The operation of the opening / closing mechanism configured as described above is described in detail in Patent Document 1, and in the closed (ON) state shown in FIG. 2 (a), a toggle spring force of the opening / closing spring 11 applied to the toggle shaft 13 is received to toggle. The first link 9 and the second link 10 of the link 8 are extended so as to be aligned substantially in a straight line, whereby the contact holder 4 receives counterclockwise torque about the opening / closing shaft 4a and the movable contact 3 Abutting against the fixed contact 2, contact pressure is applied between the fixed / movable contacts.
When the handle 5 is moved from the closed state to the right side (OFF position) in the figure, the handle lever 6 rotates clockwise around the support shaft 6a at the lower end as shown in FIG. As a result, the line of action of the opening / closing spring 11 with respect to the toggle link 8 is reversed from the left to the right, and the first link 9 and the second link 10 are buckled in the reverse “<” shape, and the contact holder 4 is rotated clockwise. By rotating, the movable contact 3 is separated from the fixed contact 2 and the contact is turned off. Further, when the handle 5 is moved from the open state to the ON position, the contact holder 4 is rotated counterclockwise by the reversing operation of the opening and closing spring 11, and the closed state shown in FIG.
Japanese Patent No. 3166908 (FIG. 6) Japanese Patent Laid-Open No. 10-125205

By the way, the above-described conventional opening / closing mechanism has the following problems. That is, in the configuration of FIG. 2, the first link 9 and the second link 10 of the toggle link 8 extend in the vertical direction via the toggle shaft 13, and the open / close spring (tensile coil spring) 11 is handled at this position. It is stretched between the top of the lever 6 and the toggle shaft 13. For this reason, the arrangement space of the opening / closing spring 11 that can be secured in the opening / closing mechanism built into the circuit breaker case 1 with a limited height is small, and the opening / closing spring 11 is a short tension coil spring under the restriction of the arrangement space. Become. Therefore, it is difficult to apply a large contact pressure between the fixed / movable contacts in the closed state by increasing the spring load of the open / close spring 11.
In addition, if the open / close spring 11 is a tension coil spring, a large stress is applied to the hooks formed at both ends of the spring every time the circuit breaker is opened and closed. There is also a problem with sex.

  The present invention has been made in view of the above points, and its object is to solve the above-mentioned problems, effectively utilizing the arrangement space in the circuit breaker case with a limited outer size, and opening and closing that acts on the driving node of the toggle link The purpose of the present invention is to provide an improved circuit breaker switching mechanism that increases the spring load of the spring to increase the contact pressure between the fixed / movable contacts in the closed state, and to reduce the size of the circuit breaker. And

In order to achieve the above object, according to the present invention, the rotary contact holder holding the movable contact is linked to the handle lever of the opening / closing operation handle, and is driven by the ON / OFF operation of the handle. Open / close mechanism of a circuit breaker that drives the contact holder to a closed position and an open position, and the open / close mechanism is connected to the other end of the first link and the second link via a toggle shaft serving as a driving node. In combination with a latch link shaft, a toggle link connected to the crankshaft of the contact holder, and an open / close spring spanned between the toggle shaft of the toggle link and the handle lever.
The toggle link is arranged so that the first and second links both extend downward with the toggle axis on the top, and the first link and the second link substantially overlap each other at the closing position of the movable contact, and the opening and closing The spring is a compression coil spring, and the open / close spring is connected between the lower end of the rotary spring lever, which is connected to the handle lever at the upper end and laid on the side of the toggle link, and the toggle shaft (Claim 1). .

  The spring lever is a seesaw-type lever pivotally supported in the middle of its longitudinal direction, and its upper end is pin-coupled to a long hole formed in the handle lever, and the open / close spring has a rotary spring receiving washer at both ends. It connects and it bridges over the state compressed between the lower end of the said spring lever and the toggle shaft of a toggle link via this spring receiving washer (Claim 2).

According to the above configuration, the toggle link is arranged so that the first link and the second link both extend downward with the toggle axis serving as the driving node on the upper side. The external dimensions of the circuit breaker can be reduced by reducing the height.
In addition, a spring spring lever is additionally installed in the opening / closing mechanism, juxtaposed to the side of the toggle link, and the upper end of this spring lever is connected to the handle lever, and then the lower end of the spring lever and the upper end side of the toggle link Installation required to bridge the open / close spring of the compression coil spring between the toggle shaft and the lower end of the spring lever. Space can be secured, and in the closed state, the contact spring reliability can be improved by applying a large contact pressure between the fixed contact and the movable contact by the compression spring force of the open / close spring. Durability and reliability are improved by using a compression coil spring that does not require a hook. Furthermore, the open / close spring is connected to the toggle shaft and spring lever via the rotary spring receiving washer, so that the center of the rotary spring receiving washer can be aligned even when the toggle link is reversed by turning the handle on and off. There is no fear that the compression coil spring will buckle due to the function, so that the opening and closing operation can be performed stably.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on the examples of FIGS. 1 (a) and 1 (b). In addition, in the figure of an Example, the same code | symbol is attached | subjected to the member corresponding to FIG. 2, and the detailed description is abbreviate | omitted.
That is, in the configuration of the illustrated embodiment, the first link 9 and the second link 10 of the toggle link 8 both extend downward with the toggle shaft 13 serving as the driving node upward, and the lower end of the first link 9. Is connected to a latch (not shown) via a shaft 14, and the lower end of the second link 10 is connected to a crank pin 15 of the contact holder 4 to constitute a four-bar link boosting mechanism. In the closed state of FIG. 1A, the first link 9 and the second link 10 are set so as to substantially overlap so that the boosting function works effectively. Due to this link arrangement, the required height space occupied by the opening and closing mechanism compared to the conventional structure shown in FIG. 2 (the first link 9 and the second link 10 extend in the vertical direction across the toggle shaft 13). This reduces the size of the circuit breaker.

Further, in order to bridge the opening / closing spring of a compression coil spring, which will be described later, to the opening / closing mechanism, a spring lever 16 is additionally provided on the side substantially in parallel with the toggle link 6 and the handle lever 6 as described below. It is connected to. That is, the center of the spring lever 16 is pivotally supported by the assembly frame 12 (see FIG. 2A) of the opening / closing mechanism via the shaft 16a, and the upper end of the lever is formed on the plate surface of the handle lever 6. It is pin-coupled to the long hole 6b.
Then, a compression spring load is applied to the toggle shaft 13 by bridging the open / close spring 11, which becomes a compression coil spring, between the lower end of the spring lever 16 and the toggle shaft 13 positioned on the upper end side of the toggle link 8. In addition, it is pushed upward. Here, a rotary spring receiving washer 17 is attached to both ends of the opening and closing spring 11 as a universal joint, and a pin pin formed at the tip of the washer 17 at the lower end of the spring lever 16 and a toggle shaft. 13 and the open / close spring 11 is bridged. By connecting the upper end of the spring lever 16 additionally provided in this way to the handle lever 6, the open / close spring 11 is bridged between the lower end of the spring lever 16 and the toggle shaft 13 located on the upper end side of the toggle link 8. A sufficient space for arrangement is required.

With the above configuration, in the closed state (ON) shown in FIG. 1A, the spring lever 16 connected to the handle lever 6 is restrained and held at the illustrated position, and the spring of the opening / closing spring 11 that becomes a compression coil spring at this position. A force (arrow F) is applied to the toggle link 8 so as to push the toggle shaft 13 upward from the left side of the drawing. The spring force of the opening / closing spring 11 is transmitted to the contact holder 4 via the second link 10, whereby the contact holder 4 receives a counterclockwise torque about the opening / closing shaft 4 a and the movable contact 3 The fixed contact 2 is pressed to give a contact pressure necessary for energization between the contacts.
On the other hand, when the handle 5 is moved clockwise from the above-mentioned closed state toward the OFF position, the handle lever 6 rotates clockwise around the support shaft 6a on the distal end side as shown in FIG. 1B. At the same time, following this movement, the spring lever 16 rotates largely clockwise around the support shaft 16a, and the lower end of the lever moves to the left side of the toggle link 8. As a result, the line of action of the open / close spring (compression coil spring) 11 spanned between the lower end of the spring lever 16 and the toggle shaft 13 of the toggle link 8 is reversed from the state of FIG. Then, the toggle shaft 13 is pushed rightward as opposed to FIG. As a result, the first link 9 of the toggle link 8 rotates clockwise about the shaft 14 and simultaneously the contact holder 4 rotates clockwise via the second link 10 so that the movable contact 3 is fixedly contacted. It is pulled upward from the child 2 and moved to the opening position. When the handle 5 is moved to the left from the open state (OFF) toward the ON position, the open / close spring 11 is reversed to return to the closed state shown in FIG.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of a structure and operation | movement of an opening-and-closing mechanism by the Example of this invention, (a), (b) is a figure showing the closing state of a movable contact, and the opening state, respectively. It is explanatory drawing of a structure and operation | movement of the switching mechanism by the prior art example of a circuit breaker, (a), (b) is a figure showing the closing and opening state of a movable contact, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit breaker case 2 Fixed contact 3 Moveable contact 4 Contact holder 5 Handle 6 Handle lever 8 Toggle link 9 First link 10 Second link 13 Toggle shaft 16 Spring lever 16a Support shaft 17 Rotating spring receiving washer

Claims (2)

The rotating contact holder holding the movable contact and the handle lever of the open / close operation handle are linked to each other, and the contact holder is driven to the closed and open positions by following the ON / OFF operation of the handle. A circuit breaker opening / closing mechanism that connects the other ends of the first link and the second link, which are interconnected via a toggle shaft serving as a driving node, to the latch connection shaft and the crank shaft of the contact holder, respectively. In a combination of a toggle link connected and installed, and an open / close spring spanned between the toggle shaft of the toggle link and the handle lever,
The toggle link extends downward with the toggle axis upward, and is arranged so that the first link and the second link substantially overlap at the closed position of the movable contact, and the opening and closing spring is a compression coil spring. An opening / closing mechanism for a circuit breaker, characterized in that the opening / closing spring is spanned between the lower end of a rotary spring lever that is connected to the handle lever and the upper end is connected to the side of the toggle link and the toggle shaft. 2. The open / close mechanism according to claim 1, wherein the spring lever is a seesaw-type lever pivotally supported in the middle of its longitudinal direction, and its upper end is pin-coupled to a long hole formed in the handle lever, and the open / close spring is pivoted at both ends thereof. An opening / closing mechanism for a circuit breaker, characterized in that a spring receiving washer is coupled and is bridged in a compressed state between the lower end of a spring lever and a toggle shaft of a toggle link via the spring receiving washer.

Images