JPS6019488Y2 - Short circuit device for differential relay case - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a short circuit device for a draw-out type differential relay case.

A differential relay system is generally used for equipment protection.

, FIG. 1 is a simplified diagram of a differential circuit for protecting a transformer, for example, in which secondary currents 11 and I2 are extracted from the input and output sides of the transformer 1 by current transformers 2 and 3, respectively. The difference between the suppression coils 4 and 5 and the operating coil 6 is taken out to the operating coil 6 of the differential circuit 7 of the differential relay.

The terminals of a differential circuit 7 constituted by suppressing coils 4 and 5 and operating coil 6 connected in an inverted T-shape are designated as l and m.

Thus, if an abnormality occurs in the transformer 1, which is the equipment to be protected, it is detected by the operating coil 6 having terminals s and t.

There is a pull-out type differential relay in which the external circuit and internal elements of the relay are connected by a connection plug, but when the connection plug is removed while the load current is flowing, In order to prevent the secondary circuit of the current transformer from becoming open, a shorting device is provided to short-circuit points l and m, as shown in FIG.

FIGS. 2 to 4 show the conventional shorting device described above.

Figure 2 is a plan view of the case side terminal part 8 of the relay;
B is a cross-sectional view taken along the line A-A', and 9 in the figure is the insulating plate 1.
1 is a case side contact piece connected to the external circuit side terminal plate 9 and urged upward (in the figure) by a coil spring 12;
Reference numeral 3 designates a differential circuit collective shorting plate that collectively shorts three or four terminals by combining the operating coil terminal and the suppression coil terminal of the differential circuit.

When the coil spring 12 is in an uncompressed state (the connection plug is removed), the free end 14 of the case-side contact piece 11 is in contact with the lower surface of the tip of the short circuit plate 12.

In FIG. 3, 15 is an element-side terminal part of the relay, 16 is an element-side terminal plate, 17 is an insulating plate, and 18 is connected at one end to the element-side terminal plate, and is lowered (in the figure) by a coil spring 19. This is an element-side contact piece that is biased towards, and is disposed opposite to the case-side terminal portion 8.

The connection plug 20 has a contact portion 21 made of a metal plate vertically from the tip to near the center, and is inserted between the case side terminal portion 8 and the element side terminal portion 15.

The connection plug 20 is inserted to the right (in the figure), and the third
In the state shown in the figure, the element side contact piece 18 and the case side contact piece 1
1 is connected by the contact plug 20, but the coil spring 12 is not yet compressed and the free end 14 of the case side contact piece 11 remains in contact with the differential circuit collective shorting plate 13, so the differential circuit is still connected. There is a short circuit.

When the connection plug 20 is further inserted to the right from this state, the coil spring 12 is compressed by the connection plug 20 as shown in FIG. 4, and the free end 14 of the case side contact piece 11 shorts the differential circuit. Away from the plate 13, the short circuit is released and the connection between the relay external circuit and internal elements is complete.

However, in the above-mentioned device, due to variations in components and assembly technology, when the connecting plug 20 is inserted, the case side contact piece 11 separates from the differential circuit collective shorting plate 13 at the same time, causing a short circuit. Since it is extremely difficult to release the short circuit, the operating coil terminal k may be released from the short circuit momentarily earlier than the other terminals, which has the drawback of causing the differential relay to malfunction.

In view of the above circumstances, an object of the present invention is to provide a short-circuiting device for an element draw-out type relay case that prevents malfunctions by preventing short-circuiting of the operating coil from being released earlier than other terminals. In order to achieve this purpose, the present invention provides, in addition to the above-mentioned collective shorting plate for the differential circuit, a shorting plate dedicated to the operation coil terminal of the differential circuit so that the operation can be performed by the difference in the insertion stroke of the connecting plug. This forcibly delays the release of the short circuit in the coil.

Embodiments of the present invention will be described below based on the drawings.

FIG. 5A shows a plan view of the case side terminal section 22.
In addition to the differential circuit collective shorting plate 23, both ends of the operating coil (first
Terminal S connected to figure s, t).

t is provided, and an operating coil-dedicated shorting plate 24 that short-circuits the terminals s and 24 is placed further back than the differential circuit collective shorting plate 23 in the connection plug insertion direction.

FIG. 5B is a cross-sectional view taken along the line 13-B' showing the differential circuit terminal section including the differential circuit collective shorting plate 23, in which the insulating plate 25 and the external circuit side terminal plate 26 are almost the same as in the conventional example described above.
, a case side contact piece whose one end is connected to the external circuit side terminal plate 26 and biased by a coil spring 27, and a differential circuit collective shorting plate 23 with which the free end 29 of the case side contact piece 28 comes into contact when the connection plug is removed. It is configured.

FIG. 5C is a cross-sectional view taken along the line C-C' showing the operating coil exclusive terminal section including the operating coil exclusive shorting plate 24, including the insulating plate 25, the external circuit side terminal plate 26, and the external circuit side terminal plate 2.
A leaf spring-shaped auxiliary contact piece 3 whose one end is connected to the left end of 6
1. A case side contact piece 33 located to the right of the auxiliary contact piece 31, one end connected to the external circuit side terminal plate 26, and biased by a coil spring 32;
It is constituted by a short-circuiting plate 24 dedicated to the working coil, which the free end 34 of the working coil contacts.

As shown in FIG. 6, the element-side terminal portion 35 is composed of an element-side terminal plate 36, an insulating plate 37, a coil spring, and an element-side contact piece 39, similar to the conventional example described above.

Reference numeral 40 denotes a connection plug having contact portions 41 divided from the tip to the upper and lower surfaces of the center.

Next, the operation of the above-described apparatus of the present invention will be explained.

6 to 8 show the differential circuit terminal A and the operating coil dedicated terminal B in accordance with the insertion position of the connection plug 40.

In FIG. 6, the connection plug 40 is inserted and the case side contact piece 28 and the element side contact piece 39 are connected at the differential circuit terminal A, but the case side contact piece 28 and the differential circuit collective shorting plate 2 are connected.
3 is also in contact and is in a short circuit state.

In the operating coil exclusive terminal B, the auxiliary contact piece 31 and the element side contact piece 39 are connected, but the case side contact piece 33 and the operating coil exclusive shorting plate 24 are in contact with each other, resulting in a short circuit state.

When the connection plug 40 is further inserted to the right until it reaches the state shown in FIG. 7, the case-side contact piece of the differential circuit terminal A separates from the differential circuit collective shorting plate 23 and the short circuit is released, but the operating coil dedicated terminal In B, the auxiliary contact plate 31 and the case-side contact piece 33 are connected to the element-side contact piece 39, but the case-side contact piece 33 and the operating coil dedicated shorting plate 24 are also in contact, resulting in a short-circuit state.

Therefore, only the suppression coil circuit of the differential circuit is formed.

Next, as shown in FIG. 8, when the connecting plug is further inserted to the right, it is compressed by the coil spring 32 and the free end 34 of the case side contact piece 33 separates from the shorting plate 24 for the operating coil, shorting the operating coil. is finally released to form the working coil circuit.

In addition, in the above embodiment, an example was explained in which the short circuit is canceled in two stages depending on the stroke difference of the connecting plug, but the configuration of the present invention is not limited to this, and for example, other switches such as micro switches, push button switches, etc. In the case of using a mechanism, it is also possible to perform the process in two stages with a time difference.

It is also possible to use the tip of the connection plug to push open the shorting mechanism at the final stage of insertion of the connection plug.

In addition, it goes without saying that various modifications can be made to the configuration of the present invention without departing from the spirit of the present invention.

As explained above, in this invention, in addition to the differential circuit collective short-circuiting mechanism, a short-circuiting mechanism dedicated to the operating coil of the differential coil is separately provided, and the short-circuit is released in two stages, so that only the operating coil circuit is released first. It is possible to prevent malfunctions of the relay due to the formation of the

[Brief explanation of the drawing]

Figure 1 is a simplified differential circuit diagram for transformer protection, Figures 2 to 4
The figures show a conventional example, Fig. 2A is a plan view of the terminal part on the case side, B is a sectional view taken along lines A- and A', Fig. 3.4 is an explanatory diagram of the operation, and Figs. Fig. 5A is a plan view of the terminal part on the case side, Fig. 5 is a sectional view taken along the line B-B', and Fig.
is a sectional view taken along the line CC', and FIGS. 6 to 8 are operation explanatory views. 22... Case side terminal section, 23... Differential circuit collective shorting plate, 24... Shorting plate dedicated to operating coil, 26... External circuit side terminal Board, 28...
...Case side contact piece, 31...Auxiliary contact piece,
33...r Case side contact piece, 35... Element side terminal section, 36... Element side terminal plate, 39...
...Element side contact piece.

Claims (1)

[Scope of utility model registration request] Insertion of the connection plug releases the short circuit between the secondary circuit connection terminals of the current transformer, and also removes the short circuit between the secondary circuit connection terminals of the current transformer. A short-circuit device for a differential relay case, characterized in that a short-circuit plate dedicated to the operating coil terminal of the differential circuit is provided, and release of the short-circuit of the operating coil is forcibly delayed by the difference in the insertion stroke of the connection plug.