JPH0850844A - Opening and closing mechanism of circuit breaker - Google Patents

Abstract

PURPOSE:To facilitate the incorporation work of a trip cross bar into the frame of an opening and closing mechanism. CONSTITUTION:A pivot 3, in which two opposite places on the periphery are made planes parallel with each other, is projected integrally from both sides of a trip cross bar 2, while bearing holes 5, which bear the pivot 3, being made at the frame 1, are opened at the end faces of the frame 1 through slits 6 a little wider than the thickness of each plane of the pivot. The incorporation of the trip cross bar 2 into the frame 1 is performed by getting the pivot 3 through slits 6 at the planes thereby inserting it into the bearing holes 5, and next, rotating the trip cross bar 2 so that the planes may be orthogonal to the slit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an opening / closing mechanism for a circuit breaker such as a wiring breaker or an earth leakage breaker, and more particularly to an improvement for facilitating the installation of a trip crossbar.

[0002]

2. Description of the Related Art FIG. 6 is a side view showing a conventional opening / closing mechanism. In the figure, the opening / closing mechanism is configured by mounting mechanical components on a frame 1 formed by bending a steel plate into a U shape. As a part of the mechanical components, the trip crossbar 2 is a side plate facing the left and right of the frame 1. Support shaft 3 between 1a
This trip crossbar 2 is rotatably supported by
Is urged counterclockwise in the figure by a return spring 4 which is a torsion spring, and abuts against the end surface of the side plate 1a to maintain the upright state in the figure. Although details are omitted, the trip crossbar 2 is rotated by receiving a force from an overcurrent trip device (not shown) when an overcurrent state occurs, unlocks the lock of the opening / closing mechanism, and causes the trip operation. .

[0003]

However, when assembling such a conventional opening / closing mechanism, it is necessary to align the bearing holes (not shown) of the side plate 1a and the trip crossbar 2 with each other and insert the support shaft 3 therethrough. Therefore, the work was troublesome. In addition, the bearing portion of the support shaft 3 is lubricated (grease).
Since there is no reservoir, the amount of grease retained was not sufficient, and poor lubrication could occur after long-term use. The present invention
It is an object of the present invention to provide an opening / closing mechanism for a circuit breaker in which the trip crossbar can be easily assembled and which can sufficiently retain grease in its bearing portion.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an open / close mechanism for a circuit breaker in which a trip crossbar is rotatably supported by a support shaft between opposing side plates of a frame bent and formed in a U shape. On both sides of the crossbar, support shafts having flat surfaces parallel to each other at two opposing positions on the outer periphery are integrally formed to project, and a bearing hole of a side plate of a frame supporting the support shaft is formed between the flat surfaces having a width. The above object is achieved by opening the end surface of the side plate through a slit slightly wider than the thickness.

[0005]

[Operation] Assembling the trip crossbar to the frame is simple because the slit is hidden in the flat surface, the spindle is inserted into the bearing hole, and then the trip crossbar is rotated so that the flat surface is orthogonal to the slit. Is. Also,
Since a space is formed between the flat surface of the support shaft and the peripheral edge of the bearing hole, the space can be used as a grease reservoir to hold the grease.

[0006]

1 to 5 show an embodiment of the present invention in a two-pole type circuit breaker, FIG. 1 is a side view of an OFF state of an opening / closing mechanism, and FIG. 2A is a trip crossbar. 3 is a rear view, FIG. 3B is a side view of the frame, FIG. 3A is a side view of the frame, FIG. 4B is a rear view of the frame, and FIG.
5A to 5C are side views showing a procedure of assembling the trip crossbar to the frame. Note that the same reference numerals are used for the portions corresponding to the conventional example. First, in FIG. 2, the trip crossbar 2 is integrally molded from a molding resin, and the passive arms of the left and right poles that receive a force from an overcurrent trip device (not shown) stand on the top of the base portion on which the support shaft 3 is formed. It has a substantially inverted triangular front shape formed by raising. The support shaft 3 is integrally formed so as to project on both sides of the base portion, and two opposing positions on the outer periphery thereof are flat surfaces 3a (FIG. 2B) parallel to each other.

On the other hand, in FIG. 3, the frame 1 is formed by punching and bending an iron plate to form side plates 1a facing each other on the left and right.
Is formed into a U-shape with one side (Fig. 3 (A))
Side plate 1a on the other side (also on the front side) of the other side plate 1a
Has been launched higher than. A bearing hole 5 for supporting the support shaft 3 is concentrically provided on the lower rear side of the left and right side plates 1a of the frame 1, and the width w of the bearing hole 5 is the thickness between the flat surfaces 3a of the support shaft 3. A rear side end surface of the side plate 1a is opened through a horizontal slit 6 slightly wider than t. The trip crossbar 2 is assembled to the frame 1 together with the return spring 4 as shown in FIG. 1. The working procedure will be described below with reference to FIG.

As shown in FIG. 2 (B), the return spring 4 formed of a torsion spring is previously fitted into the boss portion on one root side of the support shaft 3, and one leg thereof is attached to the spring receiving groove 2a on the rear side. Insert it in and attach it to the trip crossbar 2. In FIG. 5, the trip crossbar 2 is first made horizontal as shown in (A), and is made to approach the frame 1 from the bottom surface side in the arrow direction. Then, when the other leg of the return spring 4 hits the bottom surface of the frame 1, the trip crossbar 2 is still raised while elastically deforming the same, and the support shaft 3 is made to face the slit 6 as shown in (B). . In this state, the flat surface 3a of the support shaft 3 and the slit 6 are parallel to each other.

Next, while further deforming the return spring 4, the slit 6 is dipped in the direction of the arrow on the flat surface 3a,
The spindle 3 is inserted into the bearing hole 5 as shown in FIG. After that, if the trip crossbar 2 is rotated 90 degrees in the direction of the arrow so that the flat surface 3a is orthogonal to the slit 6, the trip crossbar 2 comes into contact with the rear surface of the frame 1 and stops.
Will be assembled. In this state, the support shaft 3 has the bearing hole 5
Further, the trip crossbar 2 is pressed against the frame 1 by the return spring 4 and is held in the upright state. FIG. 4 is an enlarged view of the bearing hole 5 portion in FIG. 1, and a space 5a is provided in a portion of the bearing hole 5 opposite to the slit 6.
And the grease is retained in this space.

In the opening / closing mechanism of FIG. 1, an operating handle 7 is rotatably supported on the frame 1, and the operating handle 7 is biased clockwise by a handle spring 8 in the figure. An upper end of a link 9 made of a round bar whose both ends are bent in a U shape is connected to the operation handle 7, and the lower end of the link 9 is inserted into an arc-shaped elongated hole 10 of the frame 1. Further, a V-shaped claw 11 made of an iron plate is connected to the other end of the link 9 via an edge formed integrally with the claw 11. On the other hand, a fixed contact base 12 having a fixed contact 12a and a movable leaf spring 13 having a movable contact 13a are fixed to a case (not shown) to which the frame 1 is fixed, and although not shown in detail, the claw 11 and the movable leaf spring 1 are provided.
An opening / closing plate 14 that is vertically movable is provided between the opening and the bottom plate 3.

Therefore, when the operation handle 7 is rotated counterclockwise from the OFF state in FIG. 1, the lower end of the link 9 is guided by the elongated hole 10 and moves downward, and at the same time, the claw 11 is pushed down. The right end of the claw 11 hits the protrusion 2b of the trip crossbar 2 and is locked in the middle of the downward movement, but when it is pushed down, the claw 11 rotates counterclockwise around the protrusion 2b as a fulcrum and its left end. The opening / closing plate 14 is pushed down by and the movable plate spring 13 in contact therewith is elastically deformed. As a result, the movable contact 13a comes into contact with the fixed contact 12a, and the circuit breaker is turned on. As already mentioned, the operating handle 7
Receives a force in the clockwise direction (OFF direction) from the handle spring 8, but in this state, the toggle link mechanism composed of the operating handle 7 and the link 9 is inverted in the inverted V shape, The force from 8 is the claw 11
Acts in the direction of pushing down to continue the ON state.

The operation handle 7 is turned off from the above-mentioned ON state.
When the toggle link mechanism is turned to the direction shown in FIG. 1, the pawl 11 is pulled up and the circuit breaker is turned off. Further, when the trip crossbar 2 (not shown) receives a force from the overcurrent tripping device and is rotated clockwise in the ON state due to the occurrence of the overcurrent state, the locking of the claw 11 by the convex portion 2b is released. As a result, the toggle link mechanism is reversed, the pawl 11 is pulled up by the action of the handle spring 8, and the circuit breaker is turned off (trip operation).

[0013]

As described above, according to the present invention, the orientation of the flat surface of the support shaft of the trip crossbar is aligned with the slit of the frame, and the slit is dipped in the flat surface to insert the support shaft into the bearing hole. Since the trip crossbar can be assembled to the frame only by itself, the number of parts can be reduced and the assembling work of the trip crossbar can be extremely simplified as compared with the configuration in which the support shaft of another component is inserted into the frame and the trip crossbar. Further, since there is a space between the flat surface of the support shaft and the peripheral edge of the bearing hole, the space can be used as a grease reservoir to satisfactorily hold the grease and stabilize the tripping characteristic of the circuit breaker for a long period of time.

[Brief description of drawings]

FIG. 1 is a side view of an opening / closing mechanism showing an embodiment of the present invention.

2 shows the trip crossbar in FIG. 1,
(A) is a rear view and (B) is a side view thereof.

3A and 3B show the frame in FIG. 1, in which FIG. 3A is a side view and FIG. 3B is a rear view thereof.

FIG. 4 is an enlarged view of a main part of FIG.

5A to 5C are side views sequentially showing a procedure of assembling the trip crossbar of FIG. 2 to the frame of FIG.

FIG. 6 is a side view of an opening / closing mechanism showing a conventional example.

[Explanation of symbols]

 1 Frame 1a Side plate 2 Trip crossbar 3 Spindle 3a Flat surface 5 Bearing hole 6 Slit 7 Operation handle

Claims (1)

[Claims] 1. An opening / closing mechanism of a circuit breaker in which a trip crossbar is rotatably supported by a spindle between opposing side plates of a frame formed into a U-shape, and the trip crossbar is provided on both sides of the trip crossbar on the outer circumference. A support shaft having flat surfaces parallel to each other at two opposing positions is integrally formed in a protruding manner, and a bearing hole of a side plate of a frame for supporting the support shaft is provided with a slit whose width is slightly wider than the thickness between the flat surfaces. An opening / closing mechanism for a circuit breaker, characterized in that an opening is formed on an end surface of the side plate.