JPH0537461Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to the improvement of zero-phase current transformers used in earth leakage alarms, earth leakage circuit breakers, etc. Regarding zero-phase current transformers.

(Prior Art) Conventionally, this type of zero-phase current transformer has been constructed by inserting an annular core 1 around which a secondary winding 3 is wound in a toroidal shape into an annular cup hole of a synthetic resin insulating case 4, as shown in FIG. A mounting hole 4 of the insulating case connects both ends of the winding start 3a and winding end 3b of the secondary winding, which are housed in the annular cup hole 4a and connected to the thick lead wires 2, 2, to the annular cup hole 4a.
It was common that the insulating case 4 was housed in the insulating case 4 and filled with an insulating material (indicated by a black dot).

However, recently, instead of the lead wires 2, 2, the winding start 3a of the secondary winding 3 is used as shown in FIG.
Rod-shaped terminal fittings (hereinafter referred to as pull-out pins) 6, 6 are connected to both ends of the winding end 3b, and the pull-out pins 6, 6 are connected to mounting holes that communicate with the annular cup hole 4a of the insulating case 4 that houses the annular core 1. 4b, 4b, filled with insulating material (black dots), and fixed in many cases. (For example, Utility Model Application Publication No. 53-28420) In other words, the tips of the pull-out pins 6, 6 are brought into direct contact with predetermined positions on the printed circuit board and soldered, thereby facilitating the installation work on the printed circuit board. This is to make it happen.

(Problem to be solved by the invention) Therefore, the above-mentioned pull-out pins 6, 6 are attached to the mounting holes 4b,
It must be fixed straight at the center of the pull-out pin 6, but conventionally the structure was just filled with insulating material (black dot) as described above, so the pull-out pin 6,
There have been problems in that the pull-out pins 6, 6 are mounted off-center from the centers of the mounting holes 4b, 4b, or the pull-out pins 6, 6 themselves are mounted at an angle.

The present invention was developed in view of these circumstances, and allows the pull-out pins connected to the beginning and end of the secondary winding to be accurately installed in the center of the designated mounting hole, and to prevent any tilting or falling. The purpose is to provide a zero-phase current transformer with this structure.

(Means for solving the problem) The zero-phase current transformer of the present invention that achieves the above purpose has two
An insulating case in which the annular iron core around which the secondary winding is wound is housed in an annular cup portion of an insulating case, and a pull-out pin connected to the winding start and winding end of the secondary winding is communicated close to the annular cup portion. In a zero-phase current transformer in which the annular core and the pull-out pin are fixedly arranged by filling an insulating case with an insulating material, the diameter of the pull-out pin attachment hole is equal to the secondary winding of the pull-out pin. The connection part with the secondary winding on the lower end of the pull-out pin is inserted into the mounting hole, and the cylindrical part fitted externally into the upper end of the pull-out pin It is characterized in that the positioning member is mounted in a tight fit in the mounting hole.

(Function) In other words, according to the above configuration, the pull-out pin can be installed straight in a predetermined position by simply fitting the cylindrical positioning member externally fitted onto the upper end of the pull-out pin into the pull-out pin mounting hole of the insulating case. This prevents the pin from tilting or falling. Moreover, since the connecting portion of the pull-out pin with the secondary winding is housed inside the large-diameter pull-out pin attachment hole, that is, within the insulating case, and is sealed, disconnection accidents are less likely to occur.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

(Example) FIG. 1a is a plan view showing an example of a zero-phase current transformer according to the present invention, and FIG. 1b is a sectional view taken along the line A-A in FIG. 6 is an annular iron core around which the secondary winding 3 is wound and housed in an annular cup hole 4a of the insulating case;
Reference numeral 6 denotes a drawer pin, 4d, 4, which is erected in the center of the drawer pin attaching hole by tightly fitting the positioning member 7 externally fitted on the upper part thereof into the drawer pin attaching hole 4b, 4b.
d indicates the annular cup hole 4a and the pull-out pin attachment hole 4.
A connecting hole for wiring provided between the annular core 2 and the connecting hole for storing the winding start 3a and winding end 3b of the secondary winding 3, which is extended from the annular core 2 and connected to the lower part of the pull-out pins 6, 6. The holes (black dots) in the figure indicate the insulating material filled in the insulating case.

That is, the diameter of the pull-out pin mounting holes 4b, 4b is such that the pull-out pins 6, 6 have an annular iron core 2 at the bottom thereof.
The secondary winding 3 is formed in a size that allows it to be inserted into the surrounding area with a margin in a state where the winding start 3a and winding end 3b of the secondary winding 3 are connected. Further, the depth T of the pull-out pin mounting holes 4b, 4b is smaller than the length of the pull-out pins 6, 6, and when the pull-out pins 6, 6 are inserted,
Its upper end is exposed to the outside.

Further, the positioning member 7, which is fitted onto the upper part of the pull-out pins 6, 6 and is also tightly fitted into the pull-out pin attachment holes 4b, is made of the same synthetic resin material as the insulating case 4, and is tightly fitted into the pull-out pin attachment holes 4. It is formed into a fittable shape (cylindrical in the illustrated example), and has a through hole 8 in its center for fitting the pull-out pin 6, as shown in FIG. Therefore, if this positioning member 7 is fitted onto the pull-out pins 6, 6 connected to both ends of the winding start 3a and winding end 3b of the secondary winding 3 and fitted into the pull-out pin attachment holes 4b, 4b, the pull-out pin 6 , 6 are naturally drawn-out pin mounting holes 4b, 4
The pull-out pins 6, 6 in the pull-out pin mounting holes 4b, 4b will be fixed straight at the center of the
Any movement such as inclination of the pull-out pins 6, 6 is prevented, and the connecting portions of the secondary windings 3a and 3b of the secondary windings of the pull-out pins 6, 6 are naturally accommodated in the pin mounting holes 4b, 4b. .

The through-hole 8 provided at the center of the positioning member 7 is formed to have approximately the same diameter as the pull-out pin 6 so that its inner periphery is in close contact with the outer circumference of the pull-out pin 6. The diameter of the half portion may be expanded in a tapered manner as shown in the illustrated example. In this case, the enlarged diameter portion 8
This is because b serves as a guide for the upper half portion 8a of the small-diameter through hole, and the work when externally fitting the positioning member 7 onto the pull-out pin 6 can be performed quickly.

In addition, in the illustrated example, the drawer pin mounting holes 4b, 4b
Recesses 9, 9 for the stand legs of the drawer pins 6, 6 are provided in the center of the bottom surface of the drawer pin 6, so that when the positioning member 7 is externally fitted onto the drawer pin 6, when it is fitted into the drawer pin attachment hole 4b, etc. Misalignment is prevented.

The shape of the positioning member 7 is not limited to the cylindrical shape shown in the figure, but may be any shape that allows the pull-out pin 6 to be inserted through the center and tightly fit into the pull-out pin attachment hole 4b. A prismatic shape or the like may be selected depending on the shape of 6 and the shape of the pull-out pin mounting hole 4b, but the height t should be set to prevent complete positional displacement in any of the above shapes.
At least 1/3 of the depth T of the pull-out pin mounting hole 4b
The above amount is necessary, and preferably about 1/3 to 1/2.

Furthermore, the shape of the entire zero-phase current transformer is not limited to the example shown in FIG. 1, in which the pull-out pins 6, 6 are placed at symmetrical positions around the annular core 1, for example, as shown in FIG. The shape may be appropriately selected depending on the shape and type of the printed circuit board to be attached, such as a shape in which the pull-out pins 6, 6 are arranged side by side on the side of the annular core 1.

(Effects of the invention) As explained above, according to the zero-phase current transformer of the invention, the pull-out pin can be fixed straight at the center of the predetermined pull-out pin mounting hole of the insulating case, preventing tilting or falling. This can be reliably prevented.
Therefore, attachment to the base can be performed accurately and reliably. Further, since the connecting portion of the pull-out pin with the secondary winding is completely housed in the pull-out pin mounting hole and protected by being sealed, accidents such as disconnection can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1a is a plan view showing an example of the zero-phase current transformer of the present invention, FIG. , FIG. 3 is a plan view illustrating another embodiment of the zero-phase current transformer of the present invention, and FIG. 4 is a side view taken along line B-B in FIG. FIG. 5A is a plan view illustrating the structure of a conventional general zero-phase current transformer, and FIG. 5A is a perspective view illustrating the structure of a conventional zero-phase current transformer using a pull-out pin. DESCRIPTION OF SYMBOLS 1... Annular iron core, 3... Secondary winding, 4... Insulating case, 4b... Drawer pin attachment hole, 6... Drawer pin, 7... Positioning member, 8... Through hole.

Claims (1)

[Scope of utility model registration request] The annular core around which the secondary winding is wound is accommodated in the annular cup hole of the insulating case, and the insulator is arranged so that a pull-out pin connected to the winding start and winding end of the secondary winding is brought close to and communicated with the annular cup hole. In a zero-phase current transformer that is installed in a drawer pin mounting hole of a case, and in which the annular core and the drawer pin are fixedly arranged by filling the insulating case with an insulating material, the diameter of the drawer pin mounting hole is equal to the secondary winding of the drawer pin. The connection part with the wire is formed in a size that can be inserted with plenty of room, and the connection part with the secondary winding on the lower end of the pull-out pin is inserted into the mounting hole, and the cylindrical shape that is externally fitted on the upper end of the pin is formed. A zero-phase current transformer characterized in that the positioning member is tightly fitted into the mounting hole.