JP6385737B2 - Tool for measuring transformer insulation - Google Patents

Description

  The present invention relates to a tool used for measuring insulation of a transformer (transformer) connected to a high-voltage distribution line, and particularly to measuring insulation using a high-voltage cutout connected to the primary side of the transformer. It relates to a tool suitable for use.

  In a railway facility, when a switchboard disconnection accident occurs, a transformer insulation failure may be considered as the cause of the accident, and transformer insulation measurement may be performed as one of the search operations. Conventionally, transformer insulation measurement uses a high-voltage cutout connected to the primary side of the transformer, pulls out the fuse from the high-voltage cutout, and connects the terminal at the tip of the lead wire of the insulation measuring instrument called megger to the high-voltage cutout. It was done by contacting the terminal electrode inside the out.

  However, since the terminal electrode inside the high-voltage cutout is provided at a position recessed from the fuse insertion port, it is difficult to make contact with one hand. However, as shown in FIG. 5A, the high-voltage cutout 10 and the transformer 30 are disposed at a relatively high position from the utility pole work scaffold 40, and the lead wires of the measuring instrument 50 are not so long. Therefore, the measurer must hold the main body of the measuring instrument with one hand, and the terminal at the tip of the lead wire with the other hand must be in contact with the terminal electrode inside the high-voltage cutout 10, and the workability is extremely poor. There is a possibility that high-precision measurement cannot be performed due to poor contact between the lead wire terminal and the cut-out electrode.

  In addition, as invention of the tool using a high voltage | pressure cutout, there exist some which are disclosed by patent document 1, for example. This high-voltage cutout tool is inserted after pulling out the fuse to use the cutout as a ground fault terminal for putting the high-voltage distribution line into a power failure state when performing maintenance work on the high-voltage distribution line. It is a tool devised so that it can contact with the terminal electrode.

JP 2010-259144 A

  The tool of Patent Document 1 is for ground fault, and its use is different from that of the tool of the present invention used for insulation measurement, and the tool of the present invention contacts the secondary terminal electrode inside the high-voltage cutout. In contrast, the tool of Patent Document 1 is in contact with the terminal electrode on the primary side inside the high-voltage cutout, and the position of the electrode to be contacted is different. In addition, the primary terminal electrode inside the high-voltage cutout has almost the same position regardless of the type of cutout, but the secondary terminal electrode has a general cutout and a salt-resistant cutout. There is a problem that the height from the lower end opening (fuse insertion port) differs depending on the out, and it is difficult to handle with a common tool.

The present invention has been made in view of the above problems, and can be used for measuring insulation of a transformer (transformer) by inserting it into a high-voltage cutout and bringing it into contact with an internal secondary terminal electrode. An object is to provide a tool that is excellent in workability and does not cause an electric shock accident.
Another object of the present invention is that it can be operated with one hand to be inserted into the high voltage cutout and brought into contact with the internal secondary terminal electrode, and even if an external force is applied, the high voltage cutout can be damaged. There is no insulation measurement tool to provide.
Still another object of the present invention is to provide an insulation measurement tool that can be inserted into any of general-purpose and salt-resistant high-voltage cutouts and reliably brought into contact with an internal secondary terminal electrode. is there.

In order to achieve the above object, the present invention provides:
A fuse loading opening is formed in a skirt provided in the lower portion of the cutout body, and a fuse loading port is formed in the lower portion of the cutout body. A transformer that can be inserted into a high-voltage cutout provided with a primary terminal electrode that can be contacted by a terminal, and a secondary terminal electrode that can be contacted by the other terminal of the fuse cylinder on the entrance side of the housing portion. A tool for measuring insulation,
A rod-shaped tool body having insulating properties;
A conductive contact terminal portion provided at a tip of the tool body and capable of contacting the secondary terminal electrode;
A lead wire inserted into the tool body, one end is electrically connected to the contact terminal, and the other end is extended from the rear end of the tool body;
An induction buffering member having a shape corresponding to the shape of the fuse loading port at the lower part of the cutout body and having insulation and elasticity mounted at a predetermined distance from the contact terminal portion of the tool body. When,
The predetermined distance is determined according to a distance from the secondary side terminal electrode to an inlet side end of the fuse loading port, and the contact terminal portion is in contact with the secondary side terminal electrode. The induction buffer member is configured to be fitted to the fuse loading port ,
The induction buffer member is configured to be movable in the axial direction with respect to the tool body, and the tool body is provided with a locking means capable of preventing movement of the induction buffer member toward the rear end side. did.

According to the above configuration, when the tool is inserted into the high-voltage cutout, the distance between the contact terminal portion at the tip of the tool body and the primary terminal electrode of the high-voltage cutout is sufficiently maintained, which may cause an electric shock accident. There is no. In addition, when the tool is inserted into the high-pressure cutout, the induction buffer member provided on the tool body functions as a guide member, so that the tool can be inserted accurately and easily from the axial direction, and the workability is excellent. The secondary terminal electrode is not damaged. In addition, since the induction buffering member is fitted to the fuse loading port while the contact terminal is in contact with the secondary terminal electrode, even if an external force is applied when a part of the worker's body hits the tool, the induction buffering The member does not absorb external forces and damage the high pressure cutout.
In addition, since the tool body is provided with a locking means capable of preventing movement of the induction buffer member toward the rear end side, even if an operator operating the tool slides his hand, Since further movement is prevented, it is possible to prevent accidental contact with the contact terminal portion at the tip and the secondary terminal electrode of the high-voltage cutout, and the safety of the tool can be improved.

Preferably, the secondary terminal electrode is configured to be able to engage the stepped portion on the outer periphery of the fuse cylinder and to lock the fuse cylinder by elasticity,
The contact terminal portion is configured such that a part of the secondary terminal electrode can be engaged.
According to such a configuration, since the tool is held by the secondary terminal electrode of the high-voltage cutout, the tool does not come out of the high-pressure cutout even if the tool is released from the tool after insertion. Be able to.

Further preferably, the locking means is configured to be able to lock the induction buffering member at a first position and a second position that are separated from the contact terminal portion by a predetermined distance, respectively.
The first position is determined according to the distance from the inlet side end of the first type high voltage cutout fuse loading port to the secondary terminal electrode, and the second position is a second type high voltage cutout. The structure is determined in accordance with the distance from the inlet side end of the cutout fuse loading port to the secondary terminal electrode.

  According to such a configuration, the distance from the inlet side end of the fuse loading port to the secondary side terminal electrode is inserted into both the general-purpose and salt-resistant high-voltage cutouts, and the internal secondary side terminal electrode is inserted. It can be reliably contacted. Thereby, it is not necessary to prepare an insulation measuring tool in accordance with the high pressure cutout for general use and salt resistance, and the total cost can be reduced by sharing the tool.

  According to the present invention, an insulation measurement tool excellent in workability that can be used for insulation measurement of a transformer (transformer) by being inserted into a high voltage cutout and brought into contact with an internal secondary terminal electrode is realized. can do. Further, it can be operated with one hand and inserted into the high-voltage cutout to be brought into contact with the internal secondary terminal electrode, and the high-voltage cutout is not damaged even if an external force is applied. Furthermore, it has the effect that it can be inserted into any of the general-purpose and salt-resistant high-pressure cutouts and reliably brought into contact with the internal secondary terminal electrode.

(A) is sectional drawing which shows the embodiment of the insulation measurement tool of the transformer which concerns on embodiment of this invention, and the example of the high voltage | pressure cutout suitable for salt resistance using this insulation measurement tool, (B) It is a front view which shows the example of the fuse incorporated in a high voltage | pressure cutout. It is a front view which shows the insulation measuring tool of the transformer which concerns on embodiment of this invention. It is sectional drawing which shows the state which inserted the tool for insulation measurement of FIG. 2 in the high voltage | pressure cutout (for salt tolerance) of FIG. 1 (A). It is principal part expansion explanatory drawing which shows the modification of the tool for insulation measurement which concerns on embodiment. (A) is the schematic which shows the method of the insulation measurement of the conventional transformer using a high voltage | pressure cutout, (B) is the schematic which shows the method of the insulation measurement of the transformer using the tool for insulation measurement of this embodiment. .

Hereinafter, an embodiment of a transformer insulation measurement tool according to the present invention and an example of a high voltage cutout suitable using the insulation measurement tool will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an example of a high-voltage cutout (for salt resistance) 10 and a fuse 13 built in the high-voltage cutout, and FIG. 2 is an insulation measurement tool for a transformer of this embodiment used by being inserted into the high-voltage cutout. 20 is a front view of FIG.

  First, the configuration of the high-pressure cutout 10 shown in FIG. As shown in FIG. 1B, the high-pressure cutout 10 is a cylindrical cutout main body 11, a skirt portion 12 provided at the lower part of the cutout main body 11, and the cutout main body 11. The fuse cylinder 13 is configured to be insertable into the cutout body 11 from the loading port 14 of the skirt portion 12. An opening / closing lid for closing the loading port 14 formed on the lower surface of the skirt portion 12 may be provided.

The fuse cylinder 13 loaded in the high-voltage cutout 10 is coated with a fluorescent paint at the lower end, and when the fuse blows due to overcurrent, the lower end of the fuse cylinder 13 moves downward and is visible from the loading port 14. It is comprised so that it may become a state.
A primary terminal electrode 15 </ b> A having a spring property with which the upper end of the fuse cylinder 13 is brought into contact is provided at the upper end of the fuse housing portion of the cutout body 11. In addition, the fuse storage portion inside the cutout main body 11 includes a first space 11A having a small diameter in which the main body portion of the fuse cylinder 13 is stored, and a second space portion 11B having a larger diameter than the first space. The fuse cylinder 13 is housed in the second space 11B so that the lower end of the fuse cylinder 13 is located.

Further, a step portion is formed at the boundary between the first space 11A and the second space portion 11B, and the fuse tube 13 is pushed in a predetermined length or more by contacting the step portion on the outer peripheral surface of the fuse tube 13 by the step portion. It is configured not to be.
An insulating holding sleeve 16 that holds the main body of the fuse cylinder 13 is provided in the first space 11A, and an inner portion of the second space 11B near the step portion at the boundary with the first space 11A. A secondary terminal electrode 15B having a spring property is provided on the peripheral surface.

As shown in FIG. 2, the insulation measuring tool 20 of the present embodiment is formed of an insulating material and has a rod-like shape as a whole, and the secondary terminal electrode 15 </ b> B of the high-voltage cutout 10 is formed at the tip of an insulating tool body 21. A contact terminal portion 22 made of a conductive metal that can come into contact with the contact terminal portion 22 is provided, and a rear end of the tool body 21, that is, an end portion on the opposite side to the contact terminal portion 22 is a handshake portion 23.
A through hole through which the lead wire 24 is inserted is formed in the tool body 21 in the axial direction, and the other end of the lead wire 24 inserted into the through hole and connected to the contact terminal portion 22 at one end is formed. It is pulled out from the rear end face of the handshake part 23. Although not shown in the drawings, a clip is provided at the other end of the lead wire 24 so that electrical connection can be achieved by sandwiching the probe at the end of the lead wire of the megar. Instead of the clip, a connector into which a probe or an extension cord plug can be inserted may be provided.

  In addition, in the insulation measuring tool 20 of the present embodiment, the shape of the head portion of the contact terminal portion 22 is configured to be engageable with the secondary terminal electrode 15B. Specifically, since the secondary terminal electrode 15B is formed so that the cross section has a "<" shape, the height of the head of the contact terminal portion 22 is "<" It was set to be slightly smaller than the distance to the position. By configuring in this way, the head of the contact terminal portion 22 can be firmly held in a stable posture as shown in FIG. 3 by the restoring force of the secondary terminal electrode 15B.

  In addition, the insulation measuring tool 20 of the present embodiment is provided with an annular packing 25 made of a material having insulation and elasticity such as rubber at a position separated from the contact terminal portion 22 by a predetermined distance L1. ing. The distance L1 corresponds to the length L0 (see FIG. 1) of the second space portion 11B inside the cutout body 11. The outer shape of the packing 25 is formed so as to have a shape corresponding to the shape (skirt shape) of the loading port 14 at the lower end of the cutout body 11, and the insulation measuring tool 20 is placed at the lower end of the cutout body 11. As shown in FIG. 3, when the tip contact terminal portion 22 is brought into contact with the secondary terminal electrode 15 </ b> B as shown in FIG. 14 is fitted.

  The tool to be inserted into the high voltage cutout may damage the secondary terminal electrode 15B unless the center axis is aligned and inserted accurately from the axial direction. As shown in the grounding tool for cutout described in Japanese Patent Application Laid-Open No. HEI 11-151867, a portion (referred to as a guiding portion) that can be inserted into the small diameter portion (first space 11A in FIG. 1) of the fuse housing portion is provided at the tip. Is a general idea. However, when such a configuration is adopted in a tool such as the insulation measuring tool of the present embodiment that is desired to have electrical continuity with the secondary terminal electrode 15B, the outer peripheral surface of the guiding portion becomes dirty or moisture adheres. If so, the current on the primary side is high, and there is a risk that the operator may get an electric shock.

Therefore, it is conceivable to adopt a configuration in which a guide portion is not provided at the tip of the tool like the insulation measurement tool 20 of the present embodiment. However, if the guide is simply not provided at the tip of the tool, it becomes difficult to insert the tool accurately from the axial direction. If the tool is inserted from an oblique direction and pressed firmly, the secondary terminal electrode 15B is deformed. There is a possibility that the fuse cylinder cannot be inserted after the operation is completed.
On the other hand, in the insulation measuring tool 20 of the present embodiment, a packing 25 having a shape corresponding to the shape of the loading port 14 is mounted at a position separated from the contact terminal portion 22 at the tip by a predetermined distance L1. Therefore, when the tool is inserted into the cutout, the tool is guided by the packing 25 so that the tool is accurately inserted from the axial direction, and there is an advantage that there is no possibility of deforming the secondary terminal electrode 15B.

Further, in the state where the contact terminal portion 22 at the tip of the tool is in contact with and held by the secondary side terminal electrode 15B, the packing 25 is in a state of being fitted to the loading port 14, so as shown in FIG. The operator can release the hand from the cutout and handle the measuring instrument (Megger) 50 with both hands, improving workability and accidentally placing a part of the body on the insulation measuring tool 20 for the cutout. Even if an external force is applied, there is an advantage that the cutout body 11 and the internal secondary terminal electrode 15B are not damaged.
Furthermore, since the insulating packing 25 is mounted between the contact terminal portion 22 and the handshake portion 23, even if the operator slides the hand holding the handshake portion 23, the packing 25 is It functions as an anti-slip and can prevent the contact terminal portion 22 from being accidentally touched.

  In addition, as a clip provided at the extension side end portion of the lead wire 24, it is considered that an alligator clip is generally used. However, when the alligator clip is used, the metal portion of the clip is exposed. As a result, there is a possibility that an accurate measurement cannot be performed due to an electric leakage or a small contact area with the probe of the measuring instrument, resulting in an increase in contact resistance. Therefore, in the insulation measuring tool 20 of the present embodiment, a worm clip is used as the clip at the end of the lead wire.

Next, a modification of the insulation measuring tool 20 of the present embodiment will be described with reference to FIG.
The insulation measuring tool 20 shown in FIG. 4A is configured such that the packing 25 is movable, and a stopper 26 for preventing the movement of the packing 25 is detachably provided. Engaging grooves 21a and 21b for restricting the mounting position of the stopper 26 are provided at predetermined positions on the outer peripheral surface of the tool body.
As the stopper 26, for example, an Ω-shaped metal ring having a slightly smaller diameter than the outer diameter of the tool body 21 is used. When force is applied in the direction of expanding both ends of the ring, the stopper 26 is elastically deformed to increase its diameter. It is possible to move away from the groove 21a (21b), and when the finger is released, the diameter becomes small due to the elastic restoring force, and it is possible to engage with the engaging groove 21a (21b) to make it difficult to move.

The high-pressure cut-out includes general-purpose ones in addition to the salt-resistant ones shown in FIG. The major difference between the salt-resistant one and the general-purpose one is that the salt-resistant one has a distance L0 (from the loading port 14 at the lower end of the cutout body 11 to the secondary terminal electrode 15B than the general one. 1) is short.
In the insulation measuring tool 20 shown in FIG. 4 (A), the positions of the engaging grooves 21a and 21b for restricting the mounting position of the stopper 26 are the terminals on the secondary side from the loading port 14 in the salt-resistant one and the general one. It is set according to the distance to the electrode 15B. In a tool having such a function, when measuring insulation of a transformer to which a cutout for salt resistance is attached and when measuring insulation of a transformer to which a general cutout is attached, The same tool can be used, and the tool can be inserted into the cutout in an optimal state by moving the mounting position of the stopper 26.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the said embodiment, Unless it deviates from the summary of invention, it can change suitably. For example, the locking means for preventing the movement of the packing 25 is not limited to the metal ring (stopper 26) and the engagement grooves 21a and 21b on the outer peripheral surface of the tool body 21 as shown in FIG. As shown in FIG. 4B, a configuration may be adopted in which a protruding portion 25 a that can engage with the engaging groove 21 a or 21 b on the outer peripheral surface of the tool body 21 is formed on the inner peripheral surface of the packing 25. 4B, as shown in FIG. 4C, a projecting portion 21c is formed on the outer peripheral surface of the tool body 21, and an engagement groove 25c is formed on the inner peripheral surface of the packing 25. It is also good.

DESCRIPTION OF SYMBOLS 10 High voltage cutout 11 Cutout main body 12 Skirt part 13 Fuse cylinder 14 Loading port 15A Primary side terminal electrode 15B Secondary side terminal electrode 20 Insulation measurement tool 21 Tool main body 21a Engaging groove 22 Contact terminal part 23 Handshake part 24 Lead wire 25 Packing (Induction cushioning member)
26 Stopper

Claims (2)

A fuse loading opening is formed in a skirt provided in the lower portion of the cutout body, and a fuse loading port is formed in the lower portion of the cutout body. A transformer that can be inserted into a high-voltage cutout provided with a primary terminal electrode that can be contacted by a terminal, and a secondary terminal electrode that can be contacted by the other terminal of the fuse cylinder on the entrance side of the housing portion. A tool for measuring insulation,
A rod-shaped tool body having insulating properties;
A conductive contact terminal portion provided at a tip of the tool body and capable of contacting the secondary terminal electrode;
A lead wire inserted into the tool body, one end is electrically connected to the contact terminal, and the other end is extended from the rear end of the tool body;
An induction buffering member having a shape corresponding to the shape of the fuse loading port at the lower part of the cutout body and having insulation and elasticity mounted at a predetermined distance from the contact terminal portion of the tool body. When,
The predetermined distance is determined according to a distance from the secondary side terminal electrode to an inlet side end of the fuse loading port, and the contact terminal portion is in contact with the secondary side terminal electrode. The induction buffer member is configured to be fitted to the fuse loading port ,
The induction buffer member is configured to be movable in the axial direction with respect to the tool body, and the tool body is provided with a locking means capable of preventing movement of the induction buffer member toward the rear end side. A tool for measuring insulation of transformers. The locking means is configured to be able to lock the induction buffer member at a first position and a second position that are separated from the contact terminal portion by a predetermined distance, respectively.
The first position is determined according to the distance from the inlet side end of the first type high voltage cutout fuse loading port to the secondary terminal electrode, and the second position is a second type high voltage cutout. 2. The transformer insulation measurement tool according to claim 1 , which is determined in accordance with a distance from an inlet side end of a cutout fuse loading port to the secondary terminal electrode. 3.