JPH0589768A - Through conductor of zero phase current transformer - Google Patents

Abstract

PURPOSE:To contract the longitudinal dimension of a through conductor. CONSTITUTION:A conductor extending through the through hole 2a of a zero phase current transformer 2 is divided into a front conductor 11 and a rear conductor 12, and they are inserted to the zero-phase current transformer 2 from the front and rear, then mutually butted oh tapered surfaces 14, 16 and connected by a screw 13. Thus, even if connecting conductor parts 11a, 12a in the front and rear of the current transformer 2 are formed at a right angle to through conductor parts 11b, 12b passed through the through hole 2a as shown in the drawing, the insertion to the through hole 2a can be performed, and since the axial fastening force of the screw is enlarged by the wedge effect of the tapered surfaces 14, 15, a high contact pressure can be provided in the connecting part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor which penetrates a zero-phase current transformer of an earth leakage breaker as a primary conductor.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show a conventional example. FIG. 4 is a plan view of a leakage detecting portion of an earth leakage breaker, and FIG. 5 is a front view of a zero-phase current transformer thereof. In FIG. 4, 1 is a case of an earth leakage breaker, 2 is a zero-phase current transformer, 3, 4 and 5 are through conductors of R phase, S phase and T phase which penetrate the zero phase current transformer 2, respectively. As shown in FIG. 5, the zero-phase current transformer 2 has a ring-shaped iron core 6 provided with a winding wire 7 and an outer case 8 attached thereto, and the through conductors 3 to 5 of the respective phases are provided in a center hole 2a. Is inserted. Both ends of the R-phase conductor 3 and the T-phase conductor 5 are bent leftward and rightward before and after the zero-phase current transformer 2 as shown in the figure, and the respective phase conductors 3 to 5 are bent.
Are screwed to the case 1 with a predetermined interphase distance. The S-phase conductor 4 is formed straight. Here, the upper ends of the respective phase conductors 3 to 5 in the figure are connected to a conductor connected to a not-shown interrupting portion by screws 9, and the lower ends thereof are provided with terminal screws 10 as load side terminal portions.

[0003]

By the way, the through conductor 3
-5 are molded from a copper rod in the illustrated shape, but these conductors 3-5 need to be combined with the zero-phase current transformer 2 by submerging the central hole 2a before being incorporated in the main body of the earth leakage breaker. .. Therefore, the bending angle α of the conductors 3 and 5 in FIG. 4 cannot be made very small, and as a result, conventionally, the space for accommodating the penetrating conductors 3 to 5 in the case 1 is wasted in the front-rear direction. The external dimensions of the earth leakage breaker were long. SUMMARY OF THE INVENTION It is an object of the present invention to provide a through conductor for a zero-phase current transformer in which the waste of the through conductor housing space caused by such an assembly restriction is eliminated and the leakage breaker is downsized. ..

[0004]

In order to achieve the above object, the present invention divides a conductor into front and rear portions at a portion passing through a central hole of a zero-phase current transformer, and fits the opposing surfaces with tapered surfaces. It is configured such that the corresponding concavo-convex portions are formed, and these conductors are abutted with each other with the zero-phase current transformer sandwiched therebetween and coupled by screws. By forming the tapered surface in the shape of an arc, mutual contact becomes good even when an inclination occurs between the front and rear conductors. Further, by inserting a washer made of a flexible conductive material between the uneven portions, the gap between the uneven portions due to a processing error is filled with the washer, and the contact is further improved.

[0005]

[Operation] It is necessary to divide the through conductors into the front and back, and assemble them by abutting them from the front and back of the zero-phase current transformer and connecting them with screws so that the through-hole conductors are made to lie in the center hole of the zero-phase current transformer. Therefore, the through conductor can be bent at right angles before and after the zero-phase current transformer to shorten the length in the front-rear direction. At this time, the divided conductors are fitted to each other on the tapered surface of the uneven portion and are coupled by screws, so that the tightening force of the screw in the axial direction can be expanded by the wedge effect of the tapered surface to increase the contact pressure. ..

Further, by making the tapered surface arcuate, the bending angles of the front and rear conductors are twisted and twisted when the conductor is attached to the main body case of the earth leakage breaker, and the electromagnetic force when a current flows through this conductor. Thus, even if an inclination occurs between the front and rear conductors, the inclination of the contact surface can be absorbed by the sliding of the arcuate surface, and the uneven contact of the contact surface can be reduced. Furthermore,
By inserting a flexible conductive washer between the abutting surfaces, even if a gap occurs between the tapered surfaces due to processing error,
The contact area can be increased by filling this gap with a washer.

[0007]

Embodiments of the present invention will be described below with reference to FIGS. It should be noted that the same or corresponding parts as those of the conventional example are designated by the same reference numerals. First, FIG. 1 is a plan view of the through conductor, and FIG. 2 is an arrow P of the R-phase conductor in FIG.
It is an exploded side view seen from the direction. In the figure, the R-phase through conductor 3 is a front conductor 11 having a connection portion with the main body interruption portion.
And a rear conductor 12 having a load side terminal portion,
These are connected to each other by screws 13 inside the center hole 2a of the zero-phase current transformer 2.

The connecting conductor portions 11a and 12a of the front conductor 11 and the rear conductor 12 which are located outside the zero-phase current transformer 2 are formed in the illustrated shape by punching and bending a copper plate, and the inside of the zero-phase current transformer 2 is formed. The penetrating conductor portions 11b and 12b located at are formed in the illustrated shape from a copper rod. Connection conductor part 11a
The through conductor portion 11b and the through conductor portion 11b are brazed at right angles to each other through the brazing portion, and similarly, the connection conductor portion 12a and the through conductor portion 12b are also brazed.

Here, a concave portion having a tapered surface 14 is formed at the tip of the through conductor portion 11b, and the tapered surface 14 is formed as an arcuate convex surface. A screw hole 15 into which a screw 13 formed of a countersunk screw is screwed is provided at the center. On the other hand, the tapered surface 14 is formed at the tip of the through conductor 12b.
A convex portion having a tapered surface 16 for fitting with is formed, and the tapered surface 16 is formed as an arcuate concave surface corresponding to the convex surface of the tapered surface 14. A through hole 17 through which the screw 13 passes is opened in the center. Also, the connecting conductor portion 12a
Is provided with a dish-shaped recess 18 for accommodating the head of the screw 13.

Since the T-phase conductor 5 has the same structure as the R-phase conductor 3 without permission, a description thereof will be omitted. Further, the S-phase conductor 4 is linearly integrally formed from the plate conductor as shown in FIG. 1, and is not divided into front and rear. These penetrating conductors 3 to 5 are combined with the zero-phase current transformer 2 before being incorporated in the main body of the earth leakage breaker, in which case the front and rear conductors of the R-phase conductor 3 and the T-phase conductor 5 are zero. The phase current transformer 2 is abutted from the front and the rear, and is integrally coupled with the screw 13 inside the center hole 2a. The S-phase conductor 4 is inserted into the center hole 2a as usual.

According to the above construction, the through conductors 3 and 5 are separately inserted into the center hole 2a from the front and the rear of the zero-phase current transformer 2,
After that, the screws 13 are coupled, so that the angle α in FIG. 5 is zero as shown in the figure, that is, it can be combined with the zero-phase current transformer 2 without any trouble even when bent at a right angle. Therefore, the dimension of the through conductors 3 to 5 in the front-rear direction is shortened, and the earth leakage breaker can be downsized accordingly.

Since the penetrating conductors 11b and 12b are fitted with the tapered surfaces 14 and 16, the axial tightening force of the screw 13 is applied to the tapered surfaces 14 and 16 by the wedge effect. It expands in the vertical direction to obtain a large contact pressure. Further, since the tapered surfaces 14 and 16 are arcuate surfaces, even if some inclination occurs between the penetrating conductor portions 11b and 12b, this inclination is absorbed by the sliding between the arcuate surfaces,
The uneven contact that tends to occur between flat surfaces is reduced. For these reasons, the contact resistance between the penetrating conductor portions 11b and 12b is kept low, and the temperature rise of the contact surface is suppressed.

FIG. 3 is an exploded side view of the through conductor showing an embodiment in which a washer is inserted between the butting surfaces of the through conductor portions 11b and 12b. That is, reference numeral 19 is a washer made of a flexible conductive material, which is formed in a dish shape to fit the tapered surfaces 14 and 16. This washer 19 is used when the front conductor 11 and the rear conductor 12 are connected to each other.
It is inserted between 2b and tightened with a screw 13. As a result, even if there is a slight gap between the tapered surfaces 14 and 16 due to a processing error or the like, this gap is filled with the washer 19 and the contact area at that portion increases.

[0014]

As described above, according to the present invention, the space for accommodating the through conductor is reduced, the leakage breaker is downsized, and the board on which the leakage breaker is arranged can be downsized accordingly. In addition, since the separated conductors can be coupled in a good contact state, no inconvenience such as temperature rise occurs.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is an exploded side view of the R-phase through conductor of FIG. 1 viewed from the arrow P direction.

FIG. 3 is an exploded side view of a through conductor showing another embodiment of the present invention.

FIG. 4 is a plan view of a leakage detecting portion of a leakage breaker showing a conventional example.

5 is a front view of the zero-phase current transformer shown in FIG. 4. FIG.

[Explanation of symbols]

 2 Zero-phase current transformer 3 Through conductor 14 Tapered surface 16 Tapered surface 19 Washer

Claims (3)

[Claims] 1. A conductor is divided into front and rear at a portion passing through a center hole of a zero-phase current transformer, and concavo-convex portions which are fitted to each other by tapered surfaces are formed on opposing surfaces thereof. A through-conductor for a zero-phase current transformer, characterized in that the current transformer is sandwiched and abutted against each other and coupled with a screw. 2. The through conductor for a zero-phase current transformer according to claim 1, wherein the tapered surface is formed in an arc shape. 3. The through conductor for a zero-phase current transformer according to claim 1, wherein a washer made of a flexible conductive material is interposed between the concave and convex portions that are fitted to each other.