JPH0621159Y2 - Bimetal fixed structure for small earth leakage circuit breaker - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] This invention is designed to connect a series of movable contacts to the bottom of a case made of synthetic resin for a small earth leakage circuit breaker with a rated current of about 30 amps or less, and to connect an overcurrent The present invention relates to a bimetal fixing structure for fixing a bimetal that deforms when passing and opens and closes a movable contactor through an opening / closing mechanism.

[Conventional technology]

FIG. 5 shows a conventional bimetal fixing structure. FIG. 5 is a cross-sectional view of the entire small earth leakage breaker including this fixing structure. On the bottom surface of the case 1 made of synthetic resin, the fixed contact 7b is fixed to the conductor 7a also serving as the terminal block on the input side. The fixed contactor 7 and the movable contact 3b that comes in contact with and separates from the fixed contact 7b are electrically connected in series to the movable contactor 3 at the right end of the conductor 3a of the movable contactor 3 which is fixed to the conductor 3a. The bimetal 4 is connected via the flexible bimetal 4 to be connected and the zero-phase current transformer 11 installed inside the cover 6 fixed above the bimetal 4 and arranged on the front side of the case 1.
The output-side terminal 13 connected in series with is fixed.
In the cover 6 arranged on the front side of the case 1, an opening / closing mechanism for driving the movable contactor 3 to open / close, a part of which is shown by a handle 14, a printed board unit 10 for controlling the operation of the opening / closing mechanism, and the like. Is housed. And the movable contactor 3
The bimetal 4 which is in series with the right end of the case is tightened together with the conductor 3a of the movable contact with the pad 2 integrally molded with the case 1 by using the screw 5, so that the bottom surface of the case 1 is fixed. It is fixed.

[Problems to be solved by the device]

The problems of such a bimetal fixing structure are as follows. That is, as shown in FIG. 6, the filling metal is formed into a short columnar shape having a small diameter portion formed in the axial center portion of the outer peripheral surface by cutting, and rough engraving is formed on the large diameter portion outer peripheral surface. It was carried out, and the man-hour required for production was large, and the cost was high.

An object of the present invention is to provide a bimetal fixing structure which requires less man-hours for forming the fixing structure and thereby reduces cost.

[Means for Solving the Problems]

In order to solve the above problems, according to the present invention, a bimetal fixing structure is used in which a parallel slit-shaped long hole that vertically penetrates the bottom surface of a case made of synthetic resin is formed and a plate material is used. Is formed in a U shape and its center is 1
After inserting the two sides of the fixing bracket having a screw hole formed in the center of the side face into the elongated hole, the tip portions of the two sides are deformed and fixed to the bottom surface, and the bimetal is fixed to the fixing bracket. Central 1
The structure shall be tightened and fixed to the side surface.

[Action]

When the bimetal fixing structure is formed in this way, the fixing metal fittings to which the bimetal is tightened can be manufactured by pressing, which significantly reduces the number of manufacturing steps, and requires a filling metal when casting the case made of synthetic resin. Therefore, the case can be easily molded automatically, and the fixing bracket can be automatically attached to the bottom surface of the case, so that the cost for the fixing structure can be significantly reduced.

〔Example〕

1 to 4 show an embodiment of a bimetal fixing structure according to the present invention. In the figure, the same members as those in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted. Here, FIG. 1 is a sectional view of the entire small earth leakage circuit breaker having a bimetal fixing structure according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view showing a state of inserting the fixing metal fitting into the bottom surface of the case. 3 and 4
The figures show a front view and a side view, respectively, showing a state in which the fixing fitting is inserted and fixed in the bottom surface of the case. As shown in FIG. 2, the fixing member 21 is formed in a U shape by using a plate material, a screw hole 21b is formed at the center of a surface 21a forming one side of the center, and two surfaces 21c on both sides are formed. At both ends in the front-rear direction, attach both sides 21c to the slit-shaped long holes 2 on the bottom of the case.
Guide edge to facilitate insertion work when inserting into 2a
21c ₁ and 21c ₂ are formed, and a caulking portion 21d having a narrow width and a V-shaped tip is formed at the lower end of each of the two surfaces. On the other hand, on the side of the case 22, guide grooves 22c ₁ and 22c ₂ for guiding the guide edges 21c ₁ and 21c ₂ on both sides of the fixing bracket are long holes.
The elongated hole 22a is formed so as to be connected to the longitudinal end portion of the 22a, and as shown in FIG. 3, is formed with a step in the depth direction. Therefore, when fixing the fixing bracket 21 to the bottom surface of the case 22, the lower end edges of both sides of the fixing bracket are formed into the long holes 22.
Insert the fixing bracket until it abuts the step of "a", and then push and spread the V-shaped notch protruding to the back side of the bottom surface of the case to fix it.

As shown in FIG. 1, on the surface 21a (FIG. 2) on one side of the center of the U-shaped fixing metal member fixed to the bottom surface of the case in this manner, together with the right end of the conductor 3a of the movable contact 3, The bimetal 4 is also tightened and fixed by using the screw 5.

Of course, the bimetal fixing structure of the present invention can be applied to a small-sized circuit breaker having a structure similar to that of a small earth leakage breaker.

[Effect of device]

As described above, according to the present invention, the fixing structure of the bimetal is formed by using the plate material while forming the slit-shaped long hole which vertically penetrates the bottom surface of the circuit breaker case made of synthetic resin. After inserting the two sides of the fixing bracket, which is formed in a U shape and has a screw hole formed in the central portion of the surface forming the central one side, into the elongated hole, the distal end portions of the two sides are deformed to the bottom surface. Since the structure is fixed and the bimetal is clamped and fixed to the surface of one side of the center of the fixing bracket, the fixing bracket can be manufactured by press working, the manufacturing man-hour is significantly reduced, and the circuit breaker made of synthetic resin is also reduced. The case does not need a filling metal at the time of cast molding, and the case can be easily molded automatically. Further, since the fixing metal fittings can be automatically attached to the bottom surface of the case, cost minimization can be achieved for each, and the cost related to the bimetal fixing structure can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a small earth leakage breaker having a bimetal fixing structure according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a state of inserting a fixing bracket into a bottom surface of a case according to an embodiment of the present invention, 3 and 4 are a front view and a side view, respectively, showing a state in which the fixing fitting is inserted and fixed to the bottom surface of the case, and FIG. 5 is a vertical cross-sectional view of a small earth leakage breaker having a bimetal fixing structure according to a conventional example. FIG. 6 is a perspective view of a metal embedded integrally with the bottom surface of the circuit breaker case, to which the bimetal is fixed. 1: case, 2: buried metal, 3: movable contactor, 3a: conductor,
3b: movable contact, 4: bimetal, 5: screw, 7: fixed contact, 7a: conductor, 7b: fixed contact, 21: fixed metal fitting, 22: case.

Claims (1)

[Scope of utility model registration request] 1. A fixed contact fixed to a fixed contact fixed to a conductor and a bimetal fixed in series to a movable contact fixed to and separated from the fixed contact fixed to the conductor. A parallel slit-shaped long hole that vertically penetrates the bottom surface is formed on the bottom surface of the case made of synthetic resin, and is formed in a U shape by using a plate material, and the center of the one side surface is formed. Both sides of the fixing bracket with screw holes
A small earth leakage circuit breaker characterized in that after inserting the sides into the elongated holes, the tip portions of the two sides are deformed and fixed to the bottom surface, and the bimetal is clamped and fixed to the surface of the central one side of the fixing metal fitting. Bimetal fixed structure.