JP3491859B2 - Volume reduction device for channel box - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention A channel box (hereinafter, abbreviated as a box) of a nuclear reactor is a rectangular cylinder having a long length. Into two L-shaped
Reduce the volume. However, since a clip and spacer of an irregular shape are fixed to the head of the box, they are removed in a process before vertical cutting. The present invention relates to the above-described volume reduction processing method and apparatus. [0002] Japanese Patent Application Laid-Open No. 62-257093 discloses an inner blade 4
0, a method is disclosed in which each side of the square is pressed off by the outer blade 48 and the head is cut off with the clip and the spacer in a rectangular shape. In the subsequent vertical cutting, the idea of advancing the inner cutting blade 8 to the corner of the box supported by the outer frame 88 as shown in FIG. 8 of the reference is described. Both of them are push-cutting, but there is a problem that a part of the metal sticks to the cutting blade on the pressed-cut surface and hinders smooth separation of the cutting blade. In order to remove clips and spacers as a pre-process, only the pertinent portion is removed by cutting with an end mill, and the box is not cut. The vertical cutting of the box also depends on the end mill. However, a circular saw can be used. A tool table that can be raised and lowered in a fixed section is provided on the building in the pool, and an end mill is mounted on the tool stand so that the corner of the upright box can be cut vertically, and the bottom is cut upward. When the vertical cutting of this section is completed, the box is lowered and the next section starts cutting again from below. A box in which a core bar is erected on an elevating table is prepared, and a box is inserted into and fixed to the core bar. A multi-stage cylinder is attached to the elevating table so that the box can be raised and lowered.
The end mill work is different from the push-off work, and the cutting can be done without difficulty. By repeating the divided vertical cutting, it is possible to cut the entire length without difficulty using a small tool stand device. [0004] First, the box B will be described. As shown in FIG. 1, a reinforcing column Ba is fixed to the upper end and a pair of spacers Bb are fixed to the upper surface of the rectangular columnar body. The box is 13 cm in both sides and the height is about 4.5 m. Clip B
As for a and the spacer Bb, as shown in FIG. 2, the vertical end mill M1 faces the clip, and the horizontal end mill M2 faces the spacer side surface, and only corresponding portions are cut off. The work is easy because both are at the top of the box, even in the pool. To remove the spacers, cut off the rivets and separate them from the box. Next, vertical cutting will be described with reference to FIG. The structure 1 is fixed to the pool, and a plurality of receiving surfaces are provided.
The elevating plate 2 is provided on the top of a multi-stage cylinder 3 erected on the bottom of the pool, and can be moved up and down. The square core rod 4 is fixed upright on the elevating plate, and the square box B can be loosely inserted therein. The core rod 4 is provided with an expanding portion 4a at the upper part. The expanding portion 4a comprises a horizontal cut provided in a part of the core rod as shown in FIGS. 4 and 5, and an expanding piece 5 inserted into the cut, and a piston 5a at the tip of a rod protruding from the expanding piece. Are provided in the corresponding cylinder holes, and are provided with water passage holes 4b on both sides of the piston and communicating with the upper end surface of the core rod. Expansion tabs 5 by passing water divides the box interior surface, to integrate the box and the middle stator pole. A plurality of expansion devices may be provided as necessary. The box fixing device 6 comprises an opposing pressing piece 6a mounted on the opposing receiving surface 1 in the pool so as to be able to move in and out, and can hold and fix the box B diagonally. The number of such devices may be plural if necessary. The tool stand 8 can be moved up and down along the guide 7 by rotating a ball screw 7a, and has an end mill 9 mounted thereon. As shown in FIG. 6, the box B has a diagonal line perpendicular to the receiving surface 1 and a lifting plate 2.
And the end mill 9 also moves up and down on this line. The mounting height of the guide 7 is set at the bottom of the box when the lift plate 2 is at the highest position. The operation of vertical cutting will be described in the order of steps. 1. The box transferred to the pool is inserted into the core rod. 2. The core rod and the box are integrated by the core rod expanding device. 3. The box is fixed to the construction in the pool by the box fixing device. Remove the crane. 4. Applicable part of clip on top of box with vertical end mill
Cut off. 5. Applicable part of spacer at the top of box with horizontal end mill
Cut off. The order of 4 and 5 may be reversed. 6. The cutting is started from the lower end of the box, the tool base is raised, and a predetermined section is cut and stopped. Lower the tool stand and box to the same height, and move to the vertical cutting of the adjacent upper section. During this time, the box fixing device is released and the corner is fixed. The above is repeated to affect the entire length. [0007] In contrast to the conventional method in which the head is cut in a round section, the entire length including the head is subjected to vertical cutting, so that the volume reduction effect is maximized. The work of cutting the corners of the box with an end mill or circular saw is easy. The entire length can be reliably cut by vertically moving the tool stand with a relatively short stroke.

[Brief description of the drawings] FIG. 1 is a perspective view of a box. FIG. 2 is an explanatory view of cutting a clip and a spacer. FIG. 3 is a front view of the present apparatus. FIG. 4 is a partial front view of the upright box. FIG. 5 is a plan view of the expanding device. FIG. 6 is a plan view of a partial vertical cutting device. [Explanation of symbols] Structure in 1 pool 2 Lifting plate 3 Multi-stage cylinder 4 core rod 4a Expansion part 5 Expanding pieces 5a piston 6 Box fixing device 6a Opposing pressing piece 7 Vertical guide 7a Ball screw 8 Tool stand 9 End mill B box

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-66199 (JP, A) JP-A-62-257093 (JP, A) JP-A-62-174696 (JP, A) JP-A-61-174696 165689 (JP, A) JP-A-58-135497 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21F 9/30 G21C 19/33 G21C 19/34

Claims (1)

(57) [Claims] [Claim 1] A vertical end mill that can face the upper part of the upright channel box and can cut off a portion corresponding to the clip on the upper part of the box. A horizontal end mill that can cut off the relevant part, a lifting table that can be raised and lowered from the pool floor via a multi-stage cylinder, a square core rod that is fixed upright on the lifting table, and the channel box can be loosely inserted, and a channel box An expansion device provided at a part of the corner of the core rod so that the core can be fixed to the core rod, a channel box fixing device having a pressing piece protruding from the structure so as to be able to grip the diagonal corner, and It consists of a tool base that can move up and down a certain section along the vertical guide and the cutting tool faces the corner of the box, and cuts off the clip and spacer at the top of the channel box. By cutting the opposite corners of the rectangular cross section in a fixed section from bottom to top with a cutting tool for a certain section, lowering the box and tool, and repeating the same vertical cutting, two L-shaped rods are formed. Characteristic channel box volume reduction processing device.