JP2988082B2 - Current transformer for overcurrent trip device of circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION According to the present invention, in a circuit breaker such as a wiring circuit breaker or an earth leakage circuit breaker, an overcurrent trip device for detecting a main circuit current flowing through a through conductor and transmitting a current signal. Regarding current transformer.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show a conventional structure of this type of current transformer. FIG. 3 is a perspective view of an assembled state, and FIG. It is a perspective view. First, in FIG. 3, the current transformer has a structure in which an upper coil 2 and a lower coil 3 are respectively wound on the upper side and the lower side of the square-shaped laminated core 1. The circuit breaker is fixed to a mounting portion 7 of a case 6 of the circuit breaker via a support 5 integrally caulked with the laminated core 1 by rivets 4.

In the upper coil 2 and the lower coil 3, the ends 2b and 3a of the windings are connected to each other via a connector 8, and the start 2a and the end 3b are drawn out as output leads. . An elastic tongue 5a is cut and bent at the leg of the support 5, and the current transformer is connected to the tongue 5a.
Engages with the mounting hole 7a of the mounting portion 7 and is fixed. A through conductor (not shown) is inserted through the laminated core 1 of the current transformer, and a coil composed of the upper coil 2 and the lower coil 3 outputs a current signal obtained by transforming a main circuit current flowing through the through conductor to an output terminal 2.
a, 3b.

Here, as shown in FIG. 4A, a square-shaped laminated iron core 1 is formed into a square-shaped steel sheet by combining an L-shaped steel plate 9 from the side surfaces of an upper coil 2 and a lower coil 3.
Further, these are laminated. Further, in this case, as shown in (B), the square steel plate has the L of the adjacent layer.
The configuration is such that the shaped steel plates 9 are alternately reversed left and right.

[0005]

However, the above-mentioned conventional configuration has the following disadvantages. (1) The L-shaped steel plate 9 is manually inserted into the upper coil 2 and the lower coil 3 while being turned left and right one by one while being stacked by hand. The characteristics are likely to vary due to insertion. (2) A gap is likely to be formed at the joint surface of the L-shaped steel sheets 9 to be combined, and this gap causes an increase in magnetic resistance and deteriorates characteristics. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a current transformer for an overcurrent trip device of a circuit breaker in which assembly work of a laminated iron core is simple, no operation error occurs, and the magnetic resistance is reduced. Things.

[0006]

In order to achieve the above-mentioned object, the present invention provides a square-shaped laminated iron core formed by abutting two U-shaped laminated iron cores, and these U-shaped laminated iron cores are connected to the back surface thereof. The springs inserted between the circuit breaker case and the case shall be pressed against each other. The U-shaped laminated core can be divided in either the left or right or up and down directions, and when divided into two sides, the two U-shaped laminated cores abut against each other from the side surfaces of the upper coil and the lower coil. When the square-shaped laminated core is divided into upper and lower parts, the upper coil and the lower coil are wound on two U-shaped laminated cores, respectively, and then butt against each other.

[0007]

Since the square-shaped laminated iron core is formed by abutting the iron cores laminated in a U-shape in advance, there is no need to insert and stack the steel sheets one by one through the coil, so that assembling becomes simple and no laminating error occurs. Further, since the two U-shaped laminated iron cores are pressed against each other by the spring inserted between the back surface and the case, the gap between the joint surfaces is reduced and the magnetic resistance is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that the same reference numerals are used for the portions corresponding to the conventional example. Embodiment 1 FIG. 1 is an exploded perspective view showing an embodiment in which a laminated core is divided into right and left. In the figure, reference numerals 1A and 1B denote two right and left U-shaped laminated iron cores constituting a square-shaped laminated iron core, in which U-shaped steel plates are laminated and fastened by rivets 4 via holding plates 10 on both sides to be integrated in advance. These U-shaped laminated iron cores 1A and 1B are butted in a rectangular shape from the side surfaces of the upper coil 2 and the lower coil 3 connected by the connecting plate 11 as shown by a chain line arrow. After the through conductor 12 is inserted between them, the through conductor 12 is press-fitted into the mounting portion 13 of the case 6 from above as indicated by a dashed arrow and fixed.

Here, the mounting portion 13 includes a pair of left and right walls 13a.
, And a groove 13c is provided by a rib 13b at a lower portion inside the wall 13a.
A mountain-shaped leaf spring 14 is attached to the opposite surface of the wall 13a by inserting its lower end into the groove 13c. Therefore, the U-shaped laminated core 1 press-fitted into the mounting portion 13
A and 1B receive the force from the back by the leaf spring 14 and
5 are pressed against each other. The joining surface 15 is polished.

Embodiment 2 FIG. 2 is an exploded perspective view showing an embodiment in which a laminated core is vertically divided. In the drawing, reference numerals 1A and 1B denote two upper and lower U-shaped laminated iron cores constituting a square-shaped laminated iron core, in which U-shaped steel sheets are previously laminated and integrated in the same manner as in the first embodiment. In this case, the upper coil 2 and the lower coil 3 are wound in advance before butting of the U-shaped laminated cores 1A and 1B. The upper coil 2 and the lower coil 3
Spools 2a and 3a are U-shaped laminated cores 1A from above and below.
And 1B.

The U-shaped laminated iron cores 1A and 1B are abutted from above and below in a rectangular shape, and after the through conductor 12 is inserted, they are inserted into the mounting portion 13 of the case 6 from above. Two front and rear grooves 16 are provided along the circumference, and coil springs 17 are mounted on left and right corners. On the other hand, a bottomed hole is formed in the right and left side surfaces of the holding plate 10 before and after the U-shaped laminated core 1A, and a coil spring 18 and a fixing pin 19 are sequentially inserted. The pitch before and after the fixing pin 19 and the groove 16 is the same. Therefore, the square-shaped laminated core composed of the U-shaped laminated cores 1A and 1B is pushed into the mounting portion 13 while compressing the coil spring 17 while the fixing pin 19 compresses the coil spring 18 and is pushed in. When 19 reaches the groove 16, it falls into this and is fixed up and down and back and forth.

In each of the configurations of the first and second embodiments, the square-shaped laminated iron core is constituted by the butting of the iron cores 1A and 1B which are independently laminated in a U-shape.
The L-shaped steel sheet 9 (FIG. 4) is inserted into the upper coil 2 and the lower coil 3 one by one, and the labor and time required for laminating, unlike the conventional configuration of laminating, are eliminated, and laminating errors do not occur. In addition, U-shaped laminated core 1
The joining surfaces 15 of A and 1B are collectively polished in a laminated state and pressed against each other by springs 14 and 17, so that a gap like the conventional configuration in which the individual members are simply assembled without being aligned is formed in the magnetic path. Does not occur.

[0013]

As described above, the laminated core is formed by abutting two U-shaped laminated cores, and these U-shaped laminated cores are mutually connected by the spring inserted between the back surface thereof and the case of the circuit breaker. With the pressure contact configuration, the number of assembly steps can be reduced, and characteristic failure due to an increase in magnetic resistance can be prevented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is an exploded perspective view of another embodiment of the present invention.

FIG. 3 is a perspective view of a conventional example.

4A is a perspective view showing a method of inserting an L-shaped steel sheet into the coil in FIG. 3, and FIG. 4B is a perspective view of an L-shaped steel sheet combined in a square shape.

[Explanation of symbols]

 1A U-shaped laminated core 1B U-shaped laminated core 2 Upper coil 3 Lower coil 6 Case 12 Through conductor 14 Leaf spring 17 Coil spring

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-49-43122 (JP, A) JP-A-51-80493 (JP, A) JP-A-53-135424 (JP, A) 267028 (JP, A) Japanese Utility Model 4-21046 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01H 73/36 H01H 69/00

Claims (3)

(57) [Claims] 1. A current transformer for an overcurrent trip device of a circuit breaker in which a coil composed of an upper coil and a lower coil is wound around a square-shaped laminated core forming a closed magnetic circuit, and a through conductor is inserted through the laminated core. A square-shaped laminated core is formed by abutting two U-shaped laminated cores, and these U-shaped laminated cores are pressed against each other by a spring inserted between a back surface thereof and a case of a circuit breaker. Current transformer for overcurrent trip device of circuit breaker. 2. The circuit according to claim 1, wherein the square-shaped laminated core is divided into two left and right U-shaped laminated cores, and the U-shaped laminated cores are butted against each other from the side surfaces of the upper coil and the lower coil. Current transformer for overcurrent trip device of circuit breaker. 3. The laminated iron core having a rectangular shape is divided into two upper and lower U-shaped laminated iron cores, and these U-shaped laminated iron cores are wound with an upper coil and a lower coil, respectively, and then butted against each other. 2. A current transformer for an overcurrent trip device of a circuit breaker according to claim 1.