JPS636825Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a current circuit switching device, and particularly to a current circuit switching device that is required to be always closed.

[Technical background of the invention]

FIG. 1 shows a conventional current circuit switching device.
The current circuit switching device A housed in the protective relay 2 includes a fixed piece 9, a contact 4, and a current switching contact 5 to
8 and a shorting rod 10. To connect the current circuit switching device A and the CT secondary circuit, one end of the fixed piece 9 of the current circuit switching device A is directly connected to one end of the CT circuit 1, and the other end of the CT circuit 1 is housed in the protective relay 2. After connecting to the contactor 4, the current coil 3
are connected to current switching contacts 5 to 8 of the current circuit switching device A, which are connected to arbitrary positions of the current coil 3, through one end of the current coil 3. The fixed piece 9 of the current circuit switching device A is provided with insertion holes 9a to 9e for the shorting rods 10 at positions corresponding to the contacts 4 and the current switching contacts 5 to 8, respectively, so that the shorting rods 10 can be inserted into the required positions. By inserting it into the CT circuit 1, the required current switching contacts 5 to 8 and the fixed piece 9 are connected.
The secondary circuit of is shorted. In such a conventional current circuit switching device, when changing the setting of the contact position between the current switching contact 5 and the fixed piece 9,
The shorting rod 1 is inserted through the shorting rod insertion holes 9a to 9d of the fixed piece 9.
0 is removed and the shorting rod 10 is inserted into the new setting part to complete the setting. However, as soon as the shorting rod 10 is removed from the current switching contacts 5 to 8 during this operation, the CT
Circuit 1 becomes open, leading to a major accident.
Therefore, when attempting to change the setting, first insert the preliminary shorting rod 11 into the shorting rod insertion hole 9e to short-circuit the contactor 4 and the fixed piece 9, so that the CT circuit 1 does not become open. The shorting rod 10 was removed after the CT circuit 1 was closed.

[Problems with background technology]

The above method not only requires the preliminary shorting rod 11, but also has the disadvantage that if the preliminary shorting rod 11 is forgotten to be inserted, it can lead to a major accident of opening the current circuit.

[Purpose of invention]

This invention was made with the aim of solving the above drawbacks, and does not require a spare shorting rod, and when one shorting rod is removed, it automatically short-circuits the CT2 secondary current circuit. It is an object of the present invention to provide a current circuit switching device that prevents a circuit from being electrically opened.

[Summary of the idea]

In the present invention, a movable piece formed to constantly rotate under spring pressure is provided for a contactor provided on a current source and a plurality of current switching contacts, and the contactor has a contactor having spring characteristics. The contact plate is configured to have a plate and a convex part so as to be in constant contact with the movable piece, and when the shorting rod is press-fitted between the movable piece and the contact and the push-open operation is performed, the contact plate, the convex part and Each of the shorting rods and the movable piece have a three-point wrap contact structure to prevent the current source from becoming open.

[Example of the invention]

Examples will be described below with reference to the drawings. FIG. 2 shows the configuration of an embodiment of the present invention. FIG. 3 shows a front three-dimensional view of the present current circuit switching device, and FIG. 4 shows a rear view of the current circuit switching device according to FIG. 5 shows a cross-sectional view taken along the line -' in FIG. 4, and FIG. 6 shows a cross-sectional view taken along the line -' in FIG. FIGS. 7 to 9 are diagrams for explaining the operating functions of the present current circuit switching device. 2, 3, and 4, the current circuit switching device B in the protective relay 2 is housed in the housings 22, 23, and the insertion holes 15a, 15b of the shorting rod 10...
is provided. The internal structure of the current circuit switching device B includes a movable piece 16 rotatably provided around fulcrums 20 and 20', a leaf spring 17 for pushing down the movable piece 16, and an insertion hole 1 for the shorting rod 10.
The switching contacts 5, 6... provided at positions corresponding to the switching contacts 5a, 15b... and the convex portion 18 and spring characteristics for constantly contacting the movable piece 16 when the shorting rod 10 is not inserted. It is composed of a contactor 4 having a contact plate 19. Note that although the convex portion 18 is integrally molded with the contact 4, the contact plate 19 having spring characteristics is fixed to the contact 4 with screws 21. One end of the secondary side of the CT circuit 1 is one end 16 of a movable piece 16 that is rotatably provided.
connected to a. The other end of the CT circuit 1 is first connected to the contactor 4, and then via the current coil 3 to the switching contacts 5, 6, . . . .

In Figures 2 to 4, current circuit switching device B
When performing the setting, the shorting rod 10 is inserted into any position of the insertion holes 15a, 15b, . . . of the shorting rod 10 provided in the current circuit switching device B. However, since it is not necessary to insert the shorting rod 10 into the position of the contactor 4, no insertion hole is provided. Hereinafter, the operational functions will be explained with reference to FIGS. 7 to 9. In FIG. 7, the shorting rod 10 inserted at any position of the current circuit switching device B is one of the rotatably attached movable piece 16 and the switching contacts 5, 6... provided at any position. and a leaf spring 17 that presses the movable piece 16.
contact due to the pressing force. In this state, contact 4
The convex part 18 is a contact part 24, and the contact plate 19 with spring characteristics fixed to the contactor 4 is a contact part 25 formed at its tip, and since they are in contact with the movable piece 16, the current circuit is open. I haven't gotten used to it.
That is, the movable piece 16 and the switching contact are in contact with each other through the shorting rod 10, and the convex portion 18 of the contact 4 and the contact plate 19 are also in contact with the movable piece 16, making a three-point contact with a lap contact structure. Therefore, the current circuit is in a closed state and does not open even for a moment.

FIG. 8 shows the state where the shorting rod 10 has been further inserted, and the movable piece 16 is pushed upward about the fulcrum 20 by the shorting rod 10, and at this time, the contact 4
The contact between the convex portion 18 and the movable piece 16 is broken and the movable piece 16 is released, but the contact plate 19, which has a spring characteristic and is fixed to the contact 4, moves the contact portion 25 due to the spring action.
Thus, the contact state with the movable piece 16 is maintained, and the current circuit is in a lap contact state due to the contact by the shorting rod 10.

FIG. 9 shows a state in which the shorting rod 10 is completely inserted, indicating completion of settling, and the movable piece 16 is further pushed upward about the fulcrum 20 by the shorting rod 10. At this time, the contact between the contact plate 19 and the movable piece 16 is also broken, the contact portion 25 is in an open state, and only the current setting point where the shorting rod 10 is inserted is connected, and setting is completed. In addition, when changing the setting, change the shorting rod 10 from Fig. 9 to Fig. 7.
This can be achieved by performing the reverse operation of pulling out the short-circuiting rod 10 and inserting the shorting rod 10 into another insertion hole, that is, another setting part.
In this case, since the movable piece 16 is pressed downward by the leaf spring 17, when the shorting rod 10 is removed, the contact plate 19, which was fixed to the contactor 4, comes into contact with the movable piece 16 at the contact portion 25. Then, contact plate 1
9 is pressed by the movable piece 16, the convex part 18 integrally molded with the contactor 4 is pressed by the movable piece 1 at the contact part 24.
Contact with 6. After this state, the contact between the shorting rod 10, the movable piece 16, and the switching contact at an arbitrary settling point is released. As described above, the structure is such that the current circuit is prevented from opening, and the short-circuiting rod 10 is brought into lap contact in exactly the same manner as when the shorting rod 10 is inserted, and the current circuit is not opened even for a moment. Furthermore, even when the shorting bar 10 is completely pulled out, the contact plate 24 of the convex portion 18 and the contact portion 25 of the contact plate 19 contact the movable piece 16 and short-circuit the current circuit.
9 has a spring characteristic, so even if one of the contacts becomes defective due to dust or the like, the other contact parts can prevent the current circuit from being released. In addition, since they are in contact at two places, they are strong against overload resistance of the current circuit.

The present invention is not limited to the above-mentioned embodiments, but may have the following configuration.

In the present invention, when the shorting rod 10 is pulled out, the right end contactor 4 provided in the current circuit switching device B is provided with a convex portion 18 and a contact plate 19, and is brought into contact with the movable piece 16. Depending on the specifications and conditions of the protective relay, as shown in Figure 10, the contact 4' may be located in the center, and one end of the secondary side of the CT circuit 1 may also be connected to this contact 4'. After that, it is connected to the switching contacts 5 and 6 via the current coil 3, and the rest is the same as the present invention. If the contactor 4' is thus provided at an arbitrary position and the convex portion 18 and the contact plate 19 of the contactor 4' are brought into contact with the movable piece 16, the same effect as the present invention can be obtained.

In order to prevent the current circuit from opening, in this invention,
Although the plate spring 17 is used, the same effect as the present invention can be obtained even if other springs such as a cylindrical coil spring are used.

Although the movable piece 16 is configured to be pressed by the leaf spring 17, the same effect as the present invention can be obtained even if the movable piece 16 itself is configured with a material having spring characteristics.

In the present invention, the contactor 4 has a protrusion 18 and a contact plate 1.
Although the movable piece 16 itself is provided with a convex portion 18 and a contact plate 19 at an arbitrary position.

In the present invention, the fulcrum is constructed by bending both ends of the movable piece 16, but without being particular about this, a structure that provides a fulcrum function, such as a seesaw method, may be used.

The contact plate 19 is not limited to a plate shape, but is not limited to a shape as long as it is an elastic body attached to the contactor 4, can contact the movable piece 16, and is made of a material with low electrical resistance.

[Effect of idea]

As explained above, according to the present invention, when changing the setting, when the shorting rod 10 is pulled out, the CT secondary circuit is automatically shorted, so there is no need to use a preliminary shorting rod, making the operation easier. This eliminates the occurrence of circuit release accidents due to operational errors and improves reliability.

Furthermore, when the shorting rod 10 is pulled out, the CT secondary circuit is also short-circuited by the contact plate 19 having spring characteristics and the convex portion 18.
Since it is configured with two points of contact, the contact part is fail-safe, and not only is it highly reliable against contact failure due to dust contamination, etc.
Even with respect to the overload capacity of JEC174, the standard for power protective relays (40 times the rated current, applied twice for 1 second with a 1-minute pause...for example, AC5A x 40 times = AC200A),
This results in a contact structure with sufficient margin.

Furthermore, in the conventional current circuit switching device, the fixed piece 9
was provided on the surface and the conductive part was exposed on the surface, which was dangerous when changing the setting, but in the present invention, the conductive part is housed within the housing, which improves safety.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional current circuit switching device, FIG. 2 is a configuration diagram of an embodiment of the current circuit switching device according to the present invention, FIG. 3 is a front three-dimensional view of the current circuit switching device according to the present invention, and FIG. The figure is a three-dimensional rear view of the current circuit switching device, FIG. 5 is a cross-sectional view taken at -' in FIG. 4, FIG. 6 is a cross-sectional view taken at - ' in FIG. 4, and FIGS. Diagram explaining the operating procedure, No. 10
The figure is a diagram showing a modified example. 1... CT circuit, 2... Protection relay, 3... Current coil, 4... Contact, 5-8... Current switching contact, 9... Fixed piece, 9a-9e, 15a, 15
b... Shorting rod insertion hole, 10... Shorting rod, 11...
Preliminary shorting rod, 16...movable piece, 17...plate spring,
18... Convex portion, 19... Contact plate, 20... Fulcrum of movable piece 16, 22, 23... Housing, A...
Conventional current circuit switching device, B...Current circuit switching device of the present invention.

Claims (1)

[Scope of utility model registration request] A current coil connected to one end of the current transformer secondary circuit, a plurality of contacts each connected to a plurality of taps derived from the current coil, and a plurality of contacts connected to the other end of the current transformer secondary circuit. and a movable piece rotatably provided around a fulcrum, a contact plate having a convex portion and spring characteristics provided on any one of the plurality of contacts, and the movable piece is always An initial state in the process of inserting a shorting rod between the elastic body that applies a pressing force to the movable piece so as to contact the contact plate and the convex portion, and the movable piece and a contact other than the arbitrary one contactor during settling work. Then, the contact element and the movable piece are brought into contact with each other via the shorting rod, and the arbitrary one contact element and the movable plate are brought into contact with each other through the contact plate and the convex portion, respectively. A contact other than the arbitrary one contactor is brought into contact with the movable piece via the contact plate, and the arbitrary one contact and the movable plate are brought into contact with the movable plate via the contact plate. A current circuit switching device characterized in that a movable piece is brought into contact with a contact other than any one contact using only a rod.