JPH0766078B2 - Lifting mechanism for decommissioning device - Google Patents

Description

The present invention relates to an elevating mechanism for a decommissioning device, and more specifically, it requires a long stroke downward from the operating floor of the nuclear reactor. However, the present invention relates to a lifting mechanism for a decommissioning device in which the tip (lower end) is required to have high positional accuracy and the upper direction is restricted by a ceiling or the like.

(Prior Art) As an elevating mechanism equipped in a decommissioning device for cutting internal structures and the like during nuclear reactor dismantling work, for example, a telescopic pipe system, a rack and pinion system, or a feed screw system is known. .

(Problems to be Solved by the Invention) The lifting mechanism equipped in the decommissioning device has a stroke longer than the floor and the tip (lower end).
It is required to have high positional accuracy. Further, since the upward direction is limited by the ceiling or the like, it is required that the upward stroke be shorter than the downward stroke.

However, in the lifting mechanisms proposed so far, no consideration has been given to increasing the downward stroke when there is a restriction in the upward space and eliminating the wobbling of the tip.

That is, in the elevating mechanism of the expansion and contraction tube type, the deflection of the tip becomes larger as it moves in the horizontal direction, while in the elevating mechanism of the rack and pinion method or the feed screw method, an upward space equivalent to the downward stroke is required. There was a drawback.

During the reactor dismantling operation, the internal structure of the reactor, for example, the channel box of the fuel assembly is cut along the axial direction, and this cut piece is further cut in the direction perpendicular to the axial direction to make it smaller. In the processing device (see Japanese Patent Laid-Open No. 55-26407) in which the cut pieces are stored in the storage container and processed,
It is not necessary to equip the cutting device with the elevating mechanism described above, and therefore there is no problem such as wobbling of the tip, but the mechanism becomes very complicated compared to the cutting device equipped with the elevating mechanism described above,
Moreover, the cost becomes high.

The present invention solves the above-mentioned drawbacks of the prior art. The object of the present invention is that the mechanism does not become complicated and the cost is not high, and it can be used even in a place where the space in the upward direction is limited. It is an object of the present invention to provide an elevating mechanism for a decommissioning device that requires less deflection of the tip.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the invention according to claim 1 is mounted on a horizontal movement mechanism and is provided with a furnace internal structure cutting means at the tip end of the lifting mechanism. A mechanism, a drive unit mounted on the moving mechanism, and an outer tube that is moved up and down by the drive unit,
It is characterized in that it is composed of an inner pipe that can be divided into a plurality of pipes, is detachably fixed to the outer pipe, and moves up and down together with the outer pipe.

Further, the invention according to claim 2 is characterized in that the inner pipe is configured to be dividable into a plurality of pipes having a length equal to or shorter than a lifting stroke of the outer pipe.

(Operation) The outer tube is moved up and down by a certain stroke according to the space limitation in the upward direction by the drive unit. The inner tube is usually fixed to the outer tube and moves up and down with the outer tube by a certain stroke.

When it is desired to further raise the lifting shaft of the cutting device, the fixed portion between the outer tube and the inner tube is removed to free the inner tube from the outer tube. Then, only the inner tube is pulled up by using an appropriate means until the connecting portion between the tubes comes out from the outer tube. After this, the pulled-out inner pipe, that is, the pipe protruding from the outer pipe, is removed.

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

1 to 3 show an embodiment of an elevating mechanism for a decommissioning device of the present invention.

As shown in FIG. 3, the decommissioning apparatus A includes a traveling mechanism 10 installed on an operation floor (floor) 70 of a nuclear reactor, and a traverse mechanism 20 mounted on a traveling carriage 11 of the traveling mechanism 10. A swivel mechanism 30 equipped in the traverse mechanism 20, an elevating mechanism 40 equipped in the swivel mechanism 30, and an internal structure of a reactor pressure vessel 60 equipped at the tip (lower end) of the elevating mechanism 40. It is composed of a cutting device 50 for cutting 61. Then, the traveling mechanism 10, the traverse mechanism 20, the swivel mechanism 30, and the elevating mechanism 40 can set the cutting device 50 at any position in the reactor pressure vessel 60 at any angle, and at any route. You can move it.

Here, the traveling mechanism 10 shows the traverse mechanism 20, the turning mechanism 30, and the elevating mechanism 40 (cutting device 50) mounted on the traveling carriage 11 along a traveling rail 12 by a traveling motor (not shown) in FIG. Move in the directions of arrows B and C. In addition, the traverse mechanism 20
Moves the turning mechanism 30 and the elevating mechanism 40 (cutting device 50) along the traveling rail 21 by the traveling motor (not shown) in the directions D and E shown in FIG. 3 (directions perpendicular to the directions B and D). Let The turning mechanism 30 includes a turning motor 31, a gear 32 that reduces the rotation of the turning motor 31, and a turning bearing 33 to which the rotation is transmitted from the gear 32.
The swivel bearing 33 is equipped with a swivel table 34 equipped with a lifting mechanism 40.

As shown in FIG. 1, the elevating mechanism 40 provided in the decommissioning apparatus A is moved by the traveling mechanism 10 and the traverse mechanism 20 to an arbitrary position in the horizontal direction by an arbitrary path, and a turning mechanism 30.
The lifting motor as a driving unit
41, an outer tube 42 that is moved up and down by the lifting motor 41, and a fixing member 43 such as a fixing bolt on the outer tube 42 (see FIG. 2).
And an inner pipe 44 that is fixed together with the outer pipe 42 and moves up and down together with the outer pipe 42.

Here, the lifting motor 41 is installed on the turning table 34 of the turning mechanism 30. Further, the outer peripheral surface of the outer tube 42 is guided by a rack (not shown) with which a pinion (not shown) provided on the drive shaft of the lifting motor 41 meshes, and a lifting guide 35 provided on the turning table 34. An elevating rail 46 is provided, and is moved up and down along the elevating guide 35 by the elevating motor 41. Further, the inner pipe 44 is configured to be divided into a plurality of pipes 44a having a length substantially the same as the lifting stroke of the outer pipe 42. That is, the connecting piece 4 fitted to the end of the pipe 44a.
The pipes 44a are connected to each other by the connecting member 45 constituted by 5a and the pin 45b penetrating the connecting piece 45a from the hole provided at the end of the pipe 44a, and the pipes 44a are connected to each other by pulling out the pin 45b. Can be disconnected. In other words,
The inner tube 44 can be set to an arbitrary length that is an integral multiple of the lifting stroke of the outer tube 42. A cutting device 50 is attached to the lower end (tip) of the inner pipe 44.

In the elevating mechanism 40 configured in this way, when the elevating motor 41 is operated, the outer tube 42 is guided by the elevating guide 35 to ascend and descend, and the outer tube 42 ascends and descends the inner tube 44, so that the cutting device 50 operates. The reactor internal structure 61 is cut and moved vertically in the reactor pressure vessel 60. At this time, the outer pipe 42 and the inner pipe 44 are firmly fixed by the fixing member 43, and the pipes 44a forming the inner pipe 44 are firmly connected by the connecting member 45, so that sufficient rigidity is maintained. Therefore, there is no fear that the lower end (tip) of the outer pipe 44 will shake, and the cutting operation by the cutting device 50 can be performed well.

By operating the lifting motor 41, the cutting device 50 moves up and down within the range of the lifting stroke of the outer tube 42. To move the cutting device 50 upward more than this lifting stroke, do the following. To do.

First, the outer pipe 42 is moved to the lower limit of the lifting stroke. In this state, the inner pipe 44 is hooked on a transfer device (not shown) such as an overhead crane, the fixing member 43 is removed,
The inner pipe 44 is pulled up by the conveying device by the length of one pipe 44a, that is, the length substantially equal to the lifting stroke of the outer pipe 42. Next, the pipe 44a located below the pulled-up pipe 44a is fixed to the outer pipe 42 again by the fixing member 43. Then, the pin 45b is pulled out, and the pulled up pipe 44a is removed. By sequentially removing the pipes 44a protruding from the outer pipe 42 in this manner, the cutting device 50 can be moved upward longer than the lifting stroke of the outer pipe 42. At this time, if there is a space above the outer tube 42 that is approximately equal to the lifting stroke of the outer tube 42, the tube 44a of the inner tube 44 protruding from the outer tube 42 can be removed, so that it is equivalent to the downward stroke. Space does not have to be upward.

EFFECTS OF THE INVENTION As described above, according to the first aspect of the present invention, the drive unit mounted on the moving mechanism, the outer pipe that is moved up and down by the drive unit, and the outer pipe that can be divided into a plurality of pipes Since it is composed of an inner tube that is detachably fixed to the tube and moves up and down together with the outer tube, the mechanism is not complicated and the cost is not high, and it can be used even in a place where the space in the upward direction is limited,
It is possible to provide an elevating mechanism with less deflection of the tip required for the decommissioning device.

Further, according to the invention of claim 2, since the inner pipe is configured to be divided into a plurality of pipes formed to have a length substantially equal to or smaller than the elevating stroke of the outer pipe, or a length equal to or less than the elevating stroke. As for the upward space, a space equivalent to the lifting stroke of the outer pipe is enough.

[Brief description of drawings]

1 to 3 show an embodiment of an elevating mechanism for a decommissioning apparatus according to the present invention. FIG. 1 is a side sectional view, and FIG. 2 is a sectional view taken along the line II-II in FIG. FIG. 3 and FIG. 3 are perspective views showing the installation situation of the decommissioning device for cutting equipped with the lifting mechanism of the present invention. 10 …… Travel mechanism, 20 …… Traverse mechanism 30 …… Swing mechanism, 40 …… Lifting mechanism 41 …… Drive unit, 42 …… Outer tube 43 …… Fixed member, 44 …… Inner tube 44 a …… Tube, 45 ...... Connecting member 50 …… Cutting device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tomiji Yoshida, Inventor Tomoji Yoshida, 3-1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Shinya Omori 3-chome, Hitachi-city, Ibaraki No. 1 Stock company Hitachi Ltd. Hitachi factory (56) Reference JP-A-57-161273 (JP, A)

Claims (2)

[Claims] 1. An elevating mechanism mounted on a horizontal moving mechanism and provided with a furnace internal structure cutting means at its tip, which comprises a driving unit equipped on the moving mechanism, and An elevating mechanism for a decommissioning device, comprising an outer pipe that moves up and down, and an inner pipe that is configured to be divided into a plurality of pipes and is detachably fixed to the outer pipe and that moves up and down together with the outer pipe. 2. The inner pipe is configured to be divisible into a plurality of pipes formed to have a length substantially equal to or smaller than the lifting stroke of the outer pipe. An elevating mechanism for the decommissioning device according to Item 1.