JP4856904B2 - Drilling tool for aerial switch - Google Patents

Description

  The present invention relates to a drilling tool for an aerial switch used for draining an aerial switch with water penetrating inside.

  In an aerial switch for power distribution, water may enter the interior due to an atmospheric pressure difference or rust. For this reason, the presence or absence of water in the aerial switch is regularly measured by a water immersion measuring device, and replacement work for the aerial switch in which water has entered is performed. In this case, due to construction vibrations, water that has entered the aerial switch may scatter and cause a short circuit or a ground fault inside the switch. In order to avoid such short-circuits and ground faults, a bypass cable is installed and replaced as a preliminary work.

By removing the water by making a hole in the aerial switch before the replacement work, short circuit and ground fault can be avoided and replacement work of the aerial switch can be performed. There is no need to install cables. As for the drilling tool, a tool for remotely drilling a core shroud support plate in a reactor vessel is known (see Patent Document 1).
JP-A-10-123286

  However, the drilling tool disclosed in Patent Document 1 is designed to prevent the negative effects on the reactor vessel by flowing chips generated during drilling operations into the chip basket with a large amount of high-pressure water. It does not imply a drilling tool that removes water by drilling holes in the vessel.

  As described above, it is desired that the aerial switch can be replaced quickly and at a low cost without installing a bypass cable. Can be removed. An object of this invention is to provide the drilling tool which can open a hole in the aerial switch quickly and reliably in view of such a situation.

A drilling tool for an aerial switch according to the present invention is a cylindrical drill having a first screw groove formed on an outer surface thereof, wherein the bottom plate of the aerial switch is cut into an annular shape to open a drainage hole; Provided in a cylinder of a drill, and is interposed between a pusher for cutting off an annular fragment of the bottom plate cut into an annular shape from the bottom plate by pushing, an output shaft of a prime mover, and the drill; A differential mechanism that transmits the power of the prime mover to the drill, and the differential mechanism is formed in a cylindrical shape so that the drill can be advanced and retracted in its own cylinder. A second screw groove formed on an inner surface of the nut body and a nut body that rotates in the same direction as the output shaft, and a mechanism that causes a difference in rotational speed between the output shaft, The output shaft is loosely fitted in the axial direction and engaged in the direction around the shaft. The drill is inserted in such a manner that it can be inserted and removed, and the nut body, and a screwing region in which the screw of the drill can be advanced and retracted with respect to the nut body has the output shaft attached to the drill. It includes a region that is fitted and a region in which the output shaft is separated from the drill .

  According to this structure, the drainage hole is formed in a state where the fragment in the annular shape of the bottom plate of the aerial switch that has been cut into an annular shape by the drill is pushed by the pusher and separated from the bottom plate. Is done. For this reason, the fragment in the ring does not block the drain hole due to the water pressure in the aerial switch, and the drain hole is maintained in the fully open state. As a result, water that has entered the aerial switch can be removed smoothly and reliably through the drain hole.

  If the pusher is configured to have a spring that biases it toward the bottom plate of the aerial switch, the pusher can be separated by a simple configuration.

  According to the present invention, it is possible to provide a drilling tool for an aerial switch that can quickly and surely drain water from the aerial switch.

  1 and 2 schematically show the whole aerial switch drilling tool 100. The aerial switch drilling tool 100 includes an attachment member 13 for mounting the tool 100 on the aerial switch 10, a cutting mechanism 12 for opening a drain hole in the bottom plate 14 of the aerial switch 10, And a box portion 21 for supporting the cutting mechanism portion 12 on the mounting member 13.

  As shown in FIGS. 1 to 4, the mounting member 13 has a pair of support columns 16, 16 that are arranged in parallel to each other at a predetermined interval and are provided along the bottom plate 14 of the aerial switch 10. . A presser plate 19 that contacts one side plate 15 of the aerial switch 10 is attached to one end of the pair of struts 16, 16, and a predetermined interval is provided to the other side plate 15 A of the aerial switch 10 at the other end. A mounting screw plate 17 that is open and opposed is mounted. A screw shaft 18 is screwed onto the mounting screw plate 17, and by tightening the screw shaft 18, both side plates 15 and 15 </ b> A of the aerial switch 10 are sandwiched between the presser plate 19 and the screw shaft 18. It is like that. The tool 100 is fixed to the aerial switch 10 by the mounting member 13 configured as described above.

  A box portion 21 having an open top shape is attached to the pair of support columns 16 and 16 so that the position of the box unit 21 can be adjusted in the axial direction of the support columns 16 and 16. A drain port 22 is provided at the bottom of the box portion 21.

  The box part 21 supports a motor 9, a differential mechanism 8, and a cutting mechanism part 12 including a rotating body 77 having a drill 3 at a tip part.

  As shown in FIGS. 5 to 8, the distal end portion of the rotating body 77 is formed in a cylindrical shape, and constitutes a drill 3 having cutting edges 2 and 5 on the distal end surface and the outer peripheral surface thereof. A drainage groove portion 6 is formed between the cutting blades 5 and 5 formed in a spiral shape on the outer peripheral surface. A screw 23 is formed on the outer periphery of the base end portion of the rotating body 77, and a hexagonal hole 78 opened downward is formed at the axial center position of the base end portion.

  A pusher 1 that is urged by a compression spring 7 is disposed in the space inside the cylinder 43 at the tip of the rotating body 77. The pusher 1 includes a pin-shaped portion 1a and a skirt portion 1b. The skirt portion 1b is slidably guided by a guide tube 39. The guide cylinder 39 is press-fitted and fixed in the cylinder interior 43, and the projecting position of the pin-shaped portion 1 a of the pusher 1 is restricted by the guide cylinder 39. The pusher 1 has a function of cutting off an annular portion of the bottom plate 14 cut into an annular shape by the drill 3 from the bottom plate 14 by pushing, and water is smoothly discharged from the drain hole. I try to do it.

  The motor 9 has a speed reducer inside, and an output shaft 79 having a hexagonal cross section protruding from the reducing portion 41 is inserted into the hexagonal hole 78, and the rotation of the output shaft 79 is the rotation of the rotating body 77, and consequently the drill. 3 rotations. The rotation of the output shaft 79 of the motor 9 is converted into the forward movement of the rotating body 77 (drill 3). For this purpose, the differential mechanism 8 is used. The differential mechanism 8 transmits the rotation of the output shaft 79 of the motor 9 to the gear 31 through the gear 32, and transmits the rotation of the output shaft 79 to the gear 28 through the gear 30 that is integral with the gear 31. The screw 23 of the rotating body 77 is screwed into the inner peripheral screw 26 of the nut body 24 provided. The nut body 24 can move the rotary body 77 (drill 3) forward by restricting the axial position.

The number of rotations of the output shaft 79 of the motor 9 is α, the number of teeth of the gear 32 is a, the number of teeth of the gear 31 is b, the number of teeth of the gear 30 is c, the number of teeth of the gear 28 is d, screws 26, screws If the pitch of 23 is e,
The rotational speed of the drill 3 (rotating body 77) is α, and the advance speed v of the drill 3 (rotating body 77) is as follows.

v = [alpha] * e {1- (a / b) * (c / d)}
By selecting the number of teeth a, b, c, and d, the forward speed v of the drill 3 (rotating body 77) can be appropriately reduced.

  As shown in FIGS. 1 to 4, a gripping member 20 having a substantially flat cylindrical shape is attached to the lower surface side of the box portion 21. The rotating body 77 provided with the drill 3 is inserted through a through hole formed in the bottom surface of the opening of the box portion 21 so that the tip thereof faces the bottom plate 14 of the aerial switch 10. As shown in FIG. 2, the protruding portion 42 a of the cutting mechanism portion 12 is supported by the box portion 21 by being sandwiched between the box portion 21 and the gripping member 20. The The drilling tool 100 includes a remote controller 40 for controlling the operation of the cutting mechanism unit 12.

  The operation of the drilling tool 100 configured as described above will be described. First, when the remote controller 40 is operated to drive the motor 9 of the cutting mechanism unit 12, the rotation of the output shaft 79 (see FIG. 6) of the motor 9 is converted into the rotation of the drill 3 and the forward movement in the direction of the arrow A. The drill 3 cuts the bottom plate 14 of the aerial switch 10 into an annular shape to open a drain hole. Then, the pusher 1 projects by the urging force of the compression spring 7, pushes off the piece cut and cut into an annular shape by the drill 3, moves it in the reverse direction and moves it horizontally, and opens the drainage hole in the fully open state. Remove from.

  As a result, water flows from the drain hole through the discharge groove 6 of the drill 3. At this time, when the remote controller 40 is operated to rotate the motor 9 in the reverse direction and the drill 3 is lowered and removed from the drain hole, the water in the aerial switch 10 flows out to the outside at once.

  In the present embodiment, the example in which the pusher 1 protrudes from the distal end surface of the drill 3 by the urging force of the compression spring 7 is shown, but the present invention is not limited to this. For example, the pusher 1 may be protruded by electrical means such as a solenoid.

  The present invention can be applied to a drilling tool for an aerial switch that is used to remove water from an aerial switch that has entered water.

It is a front view of the drilling tool for an aerial switch according to the present embodiment. It is a front fragmentary sectional view of the drilling tool for aerial switches which concerns on this Embodiment. It is the perspective view which looked at the attachment member of the drilling tool for aerial switches which concerns on this Embodiment from the upper side. It is the perspective view which looked at the attachment member of the drilling tool for aerial switches which concerns on this Embodiment from the lower side. It is the perspective view which looked at the cutting mechanism part of the drilling tool for aerial switches which concerns on this Embodiment from the upper side. It is a partial cross section perspective view of the drill and differential mechanism of the drilling tool for aerial switches which concerns on this Embodiment. It is a typical front sectional view of a drill and differential mechanism of an aerial switch drilling tool concerning this embodiment. (a) is a top view of the drill of the drilling tool for aerial switches which concerns on this Embodiment, (b) is the front view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pusher 3 Drill 7 Compression spring 10 Aerial switch 14 Bottom plate 100 Drilling tool

Claims (2)

A cylindrical drill having a first screw groove formed on the outer surface thereof, wherein the bottom plate of the aerial switch is cut into an annular shape to form a drainage hole;
A pusher provided in a cylinder of the drill, and for cutting off an annular fragment of the bottom plate cut into an annular shape from the bottom plate by pushing;
Is interposed between the output shaft of the prime mover and the drill, and a differential mechanism for transmitting the power of the prime mover to the drill,
The differential mechanism is formed in a cylindrical shape, and a second screw groove is formed on an inner surface so as to be screwed with the first screw groove so that the drill can be advanced and retracted in the cylinder. A mechanism for causing a difference in rotational speed between a nut body that rotates in the same direction as the output shaft and the output shaft;
The output shaft, the drill is inserted in such a manner that the output shaft is loosely fitted in the axial direction and engages in the direction around the shaft, and the nut body,
The screwing region where the drill can be advanced and retracted with respect to the nut body includes a region where the output shaft is fitted into the drill and a region where the output shaft is separated from the drill. A featured drilling tool for aerial switches. The drilling tool for an aerial switch according to claim 1, further comprising a spring that biases the pusher toward the bottom plate of the aerial switch.

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