JPH0155734B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to current circuit switching that is required to be always closed, such as the secondary circuit of a current transformer (hereinafter referred to as CT). It is related to the device.

[Technical background of the invention and its problems]

FIG. 1a shows a conventional current circuit switching device. Current circuit switching device 3 housed in protective relay 2
The movable piece 5 is rotatably provided around the fulcrum 4, the leaf spring 6 for pushing down the movable piece 5, and the switching fixed contacts 7, 8, 9, 10, 1.
1. Movable piece 5 and switching fixed contacts 7, 8, 9, 1
Short-circuit rod 1 for short-circuiting with either one of 0 and 11
2 and switching fixed contacts 7, 8, 9, 10, 1
1, and a protrusion 13a is provided at an arbitrary position as shown in FIG.
It consists of a short-circuiting fixed contact 13 that is in contact at point a.

Further, one end of the secondary side of the CT circuit 1 is connected to one end 5a of a movable piece 5 that is rotatably provided. The other end is connected to the switching fixed contacts 7, 8, 9, 10, 11 via the current coil 14.

FIG. 2 is a schematic side view of the current circuit switching device 3 centered on the short-circuit fixed contact 13, and shows the short-circuit rod 1
Fig. 2 shows temporal changes in the insertion of No. 2. If it operates ideally as shown in the same figure, the movable piece 5 will appear as shown in Figure 3 a.
Then, the protruding portion 13a of the short-circuiting fixed contact 13 is completely electrically separated. However, if the shorting rod 12 is not inserted enough, or there is an error in the dimensional accuracy during processing, or if the position of the leaf spring 6 is not accurate, the movable part may not move as shown by the dashed line in Figure b. 5 is distorted and operates, the movable piece 5 and the protrusion 13a of the short-circuiting fixed contact 13 are not completely separated, and even though the short-circuiting rod 12 is inserted, the electrical current is not substantially stabilized. malfunction occurs,
It had the drawback that it did not function as an original protection relay.

[Purpose of the invention]

The present invention was created in view of the above-mentioned drawbacks, and has a structure in which when the shorting rod is inserted into an arbitrary position and settled, the movable piece that was in contact with the protrusion of the shorting fixed contact always separates. The present invention provides a current circuit switching device having the following features.

[Summary of the invention]

In the present invention, by arranging the shorting fixed contact between the switching fixed contacts arranged in parallel, the contact between the movable piece and the shorting fixed contact can be reliably broken when the shorting rod is inserted. It is characterized by the following points.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4, in which the same parts as in FIG.
A short-circuiting fixed contact 13 having a protrusion 13a is disposed approximately at the center of the short-circuiting contact 13. Here, approximately the center is
As shown in Figure 5, the number of switching fixed contacts is n.
If n is from the leftmost edge of the front, then if the almost center position is Nth from the leftmost edge of the front, then if n is an odd number, (n+1/2)<N<(n+1/2+1)...(1 ) If n is an even number, select so that the relationship is (n/2)<N<(n/2+)...(2). To illustrate this relationship, figure a shows the case where n is an odd number, and figure b shows the case where n is an even number. As is clear from this figure,
When the number of switching fixed contacts is 5 or 7, they are placed at position X or Y in a of the figure. In addition, if the number of switching fixed contacts is 6 or 8, please refer to figure b.
It is only necessary to select and place it from any of the X, Y, or Z positions.

FIG. 12 shows the arrangement relationship between the current coil 14, the movable piece 5, the switching contacts 7, 8 to 11, and the short-circuiting fixed contact 13. In the figure, _t1 to _t5 are intermediate taps, and _ts is a short-circuit tap.

Next, the operation of the above-described configuration will be explained.

As shown in FIG. 4, by arranging the short-circuiting fixed contact 13 at approximately the center of the switching fixed contacts 7, 8, 9, 10, and 11, the short-circuiting rod 12 can be placed in the switching fixed contact 7, Even if it is inserted into any position of 8, 9, 10, 11, the insertion method is bad and the movable piece 5
Even if the movable piece 5 operates with distortion due to the position of the leaf spring 6, the opening/closing operation between the protrusion 13a of the short-circuiting fixed contact 13 located approximately in the center and the movable piece 5 will not occur. is sufficient and geometrically reasonable to ensure complete opening and closing.

The above explanation has been made with respect to the short-circuiting fixed contact 13 provided with one protrusion 13a, but as shown in FIG. 6a, two protrusions 2 on both sides
1a, 21b may be provided, or two protrusions 31a, 31 may be provided on one side as shown in FIG.
b may also be provided. Here, each protrusion 2
1a, 21b, 31a, and 31b are plated with silver, precious metal, or an alloy thereof.

By providing two or more protrusions in this manner, contact reliability during closing can be significantly improved.

Further, as shown in FIGS. 7 and 8, grooves 41b,
41c may be provided to prevent deterioration of contact reliability due to dust or the like adhering to the contact portion when the movable piece 5 comes into contact with the movable piece 5.

Furthermore, as shown in FIGS. 9 and 10, a thin plate 51b of silver or silver alloy may be fixed to the tip of the protrusion 51a of the short-circuiting fixed contact 51 by silver brazing or the like, and as shown in FIG. As shown in FIG.
1a, and by inserting and removing the shorting rod 12, the shorting fixed contact and the protrusion 61 of the movable piece 61
Alternatively, a may be opened and closed.

〔Effect of the invention〕

Since the present invention is configured as described above,
By arranging the shorting fixed contact almost in the center of the switching fixed contacts installed in parallel, even if the shorting rod is inserted at any position corresponding to the switching fixed contact, it will not work as the shorting fixed contact. The movable side is completely separated from the movable side, and a highly reliable current circuit switching device can be provided.

[Brief explanation of drawings]

Fig. 1 a, b is a schematic diagram of a conventional current circuit switching device and a perspective view of a short-circuit fixed contact; Fig. 2 a, b,
3c is an explanatory diagram showing the relationship when a shorting rod is inserted in a conventional current circuit switching device, and FIGS. FIG. 4 is a front view showing an embodiment of the present invention, FIGS. , b is a perspective view showing another example of the short-circuiting fixed contact according to the embodiment of the present invention;
The figure shows the sixth fixed contact for shorting according to an embodiment of the present invention.
A perspective view showing another example different from the figure; FIGS. 8a and b are a front view and a plan view showing an enlarged view of part A in FIG. 7;
FIG. 9 is a perspective view showing another example different from FIGS. 7 and 8 of the short-circuiting fixed contact according to an embodiment of the present invention;
FIG. 10 is an enlarged perspective view of section B in FIG. 9;
FIG. 11 is a perspective view showing another example of the movable piece according to the embodiment of the present invention, and FIG. 12 is a layout diagram of each component of the current circuit switching device according to the present invention. 3...Current circuit switching device, 5...Movable piece, 7,
8, 9, 10, 11... Fixed contact for switching, 12
... Shorting rod, 13, 21, 31, 41 ... Fixed contact for shorting.

Claims (1)

[Claims] 1 A plate-shaped movable piece that is swingably provided and whose one end is connected to one terminal on the secondary side of the CT circuit;
a plurality of fixed switching contacts each connected to an intermediate tap of a current coil connected to another terminal on the secondary side of the circuit; and a plurality of fixed switching contacts connected to a shorting tap of the current coil and facing the movable piece. a short-circuiting fixed contact having a protrusion at the bottom; a spring that constantly presses the movable piece to establish electrical continuity between the movable piece and the protrusion; and a gap between the movable piece and the optional switching fixed contact. In the current circuit switching device, the current circuit switching device includes a shorting bar that releases electrical continuity between the movable piece and the projection when inserted, and also makes electrical continuity between the movable piece and the arbitrary switching fixed contact. A current circuit switching device characterized in that a contactor is arranged at an intermediate portion of the plurality of fixed switching contacts.