JP3435125B2 - Nuclear fuel assembly device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear fuel assembly apparatus for inserting a fuel rod into a spacer and a lower tie plate to produce a nuclear fuel assembly.

[0002]

2. Description of the Related Art Generally, in manufacturing a nuclear fuel assembly,
A large number of fuel rods are successively inserted into the cells of the spacer, and their tips are inserted and attached to the lower tie plate. FIG. 3 is a diagram showing a schematic configuration of a fuel rod insertion mechanism for inserting the above fuel rods into a spacer or the like in the nuclear fuel assembly device, and in the nuclear fuel assembly device main body 1, along a slide guide 2 extending in the longitudinal direction. The insertion rod driving body 3 is movably provided. The insertion rod driving body 3 is screwed into a ball screw 5 which is rotated around an axis by a drive motor 4, and the rotation of the ball screw 5 moves along the slide guide. Then, one end of an insertion rod 6 extending parallel to the ball screw is attached to the insertion rod driving body 3. On the other hand, on one side in the axial direction of the main body 1 of the nuclear fuel assembly apparatus, a plurality of spacers 7 are mounted on a not-shown assembly stand at predetermined intervals so that their cell axes are horizontal, and at the ends thereof are of a lower type. Rate 8 is provided.

When assembling a nuclear fuel assembly, however, the fuel rod 9 is pushed by the insertion rod 6 attached to the insertion rod driving member 3 by moving the insertion rod driving member 3 and the predetermined cells of the spacer 7 and Lower tie plate 8
To insert.

However, the insertion rod 6 for inserting the fuel rod
The maximum value of the diameter and the minimum value of the length are determined due to the structure of the nuclear fuel body, and the length is longer than the diameter, about 1:18.
It is a ratio of 0. Therefore, the bending of the insertion rod occurs during automatic insertion, which hinders the insertion. Therefore, in order to prevent this bending, it is necessary to support the intermediate portion of the insertion rod 6, and as shown in FIG. 3, a plurality of insertion rod support seats 10, 10 are provided at predetermined intervals.

[0005]

However, the insertion rod support seat 10 as described above is provided on the same axis as the insertion rod that moves to push in the fuel rod, and the bending of the insertion rod is minimized. In order to do so, it is necessary that the insertion rod driving body 3 holding the insertion rod supports the insertion rod until just before passing through the insertion rod support seat 10. Therefore, when the insertion rod drive body 3 approaches the insertion rod support seat 10, it is necessary to quickly retract and allow the insertion rod drive body 3 to pass. Therefore, in order to automatically control the insertion rod support seat 10, highly precise control and a complicated mechanism are required,
There are problems that the device becomes complicated and the cost of the device increases.

In view of the above points, the present invention does not require highly precise control or a complicated mechanism, and the insertion rod support seat is reliably retracted from the insertion rod driving body and the bending amount of the insertion rod is reduced. It is an object of the present invention to obtain a nuclear fuel assembly assembling apparatus.

[0007]

The invention according to claim 1 is
In a nuclear fuel assembly apparatus having a fuel rod insertion mechanism for inserting a fuel rod into a cell of a spacer and into a lower tie plate by an axially moving rod and an inserting rod rotating around the axial line, along a moving path of the inserting rod. A plurality of insertion rod support seats, which are arranged at predetermined intervals, can be moved in a direction orthogonal to the insertion axis of the insertion rod in a direction toward or away from each other, and a pair of left and right that are always biased in a direction toward each other. The insert rod is supported by a pair of left and right supports, and the insert rod driver is attached to the insert rod driving body to which the insert rod is attached. At this time, a retracting operation member for moving the support members in the expanding and retracting direction is provided.

According to a second aspect of the invention, in the invention according to the first aspect, the pair of left and right supporting members are provided along the insertion rod.
On the horizontal part formed on the supporting seat mounting member
It is movably mounted perpendicular to the direction of the axis, connecting the are supported by a pair of right and left support seat support member which is biased approaching direction to each other, and the support seat support member supporting member
The pair of left and right shafts to be connected are provided with ball bearings that engage with the retracting operation member.

According to a third aspect of the present invention, in the invention according to the first or second aspect, a pair of left and right support members are provided with a notch concave portion having a triangular cross section on the surfaces facing each other. A ball bearing that engages with the insertion rod is provided on the inner surface of the cutout recess.

According to a fourth aspect of the present invention, in the invention of any one of the first to third aspects, the retracting operation member has a width that narrows toward the tip, and the movement thereof causes the support seat supporting member and the supporting seat to be supported. It is characterized in that a guide portion is formed which engages with a spherical bearing provided on a shaft connecting the member and the support tool and moves the support tool in a direction in which they are separated from each other.

According to a fifth aspect of the invention, in the invention according to the second aspect, the support seat supporting members are supported by slide bearings, and are biased toward each other by springs. .

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. In the figure, the same parts as those in FIG.

FIG. 1 is a diagram showing a schematic configuration of a nuclear fuel assembly apparatus according to the present invention. A nuclear fuel assembly apparatus main body 1 is screwed into a ball screw 5 which is rotationally driven by a drive motor 4, and a slide guide. An insertion rod driving body 3 is attached so as to move in the horizontal direction along 2, and an insertion rod 6 is provided on the insertion rod driving body 3 so as to project in the horizontal direction. Further, the nuclear fuel assembly apparatus main body 1 is provided with a support seat mounting member 12 for mounting each of the plurality of insertion rod support seats 11 along the insertion rod 6.

FIG. 2 is an enlarged perspective view of the insertion rod support seat 11 portion. The support seat mounting member 12 has a horizontal portion 12a formed above the insertion rod 6 and extending in a direction orthogonal to its axis. A pair of left and right slide bearings 13, 13 are provided in a straight line on the horizontal portion 12a, and support seat support members 14, 14 are provided on the slide bearings 13, 13 respectively.
Is mounted so as to be movable in a direction orthogonal to the axis of the insertion rod 6. Tension springs 15 and 15 are stretched between the support seat support members 14 and 14 and the support seat mounting member 12, and the support seat support members 14 and 14 are urged toward each other. .

The pair of left and right support seat support members 14 includes a shaft 1
Supports 17, 17 are respectively mounted via 6, and the insertion rod support seat 11 is constituted by the pair of left and right supports 17, 17. The left and right supports 17, 1
Notch recesses 1 each having a triangular cross section are formed on the surfaces of 7 facing each other.
9 is formed, and a ball bearing 20 that engages with the insertion rod 6 is provided on the inner surface of the cutout recess 19. The left and right supports 17, 17 are urged toward each other by tension springs 15 via the support seat support members 14, 14, and the insertion rod 6 is gripped from both sides by the left and right supports 17, 17. It is supposed to be supported. The shafts 16 and 16 are provided with ball bearings 18 and 18 respectively in the middle thereof.

On the other hand, a plate-shaped retracting operation member 21 is attached to the insertion rod driving body 3. The retracting drive member 21 is provided with a guide portion 22 in which a front end portion and a rear portion thereof are formed in a concave curved shape on both left and right edges so that the front end side is narrowed. Both sides of 22 are engaged with ball bearings 18, 18 provided above the support members 17, 17, and the left and right support members 17, 17 are supported together with the support seat support members 14, 14 against the tension spring 15 and are mutually separated. It is designed to move in the direction of separation.

Therefore, when the fuel rod 9 is inserted into the spacer 7 and the lower tie plate 8 in assembling the nuclear fuel assembly, the drive motor 4 is driven to move the insertion rod drive assembly 3 via the ball screw 5. Then, the insertion rod 6 is moved in the axial direction in a state of being gripped and supported by the left and right supports 17, 17, and the fuel rod 9 placed at a predetermined position is pushed in the axial direction by the insertion rod, and the spacer 7 Cells are sequentially inserted in the cell and the lower tie plate 8. When the insertion rod driving body 3 approaches the insertion rod support seat 11 during such movement of the insertion rod 6, both side edges of the guide portion 22 of the retracting operation member 20 engage with the ball bearing 18, and the guide portion 22 causes the ball to move. The left and right support tools 17, 17 are separated from each other via the bearing 18 in the direction of retreat. Therefore, the left and right supports 17, 17 of each insertion rod support seat 11 are sequentially retracted in accordance with the movement of the insertion rod 6, so that the movement of the insertion rod drive body 3 is not hindered and the insertion rod drive is performed. The insertion rod 6 is supported by the support members 17 and 17 until the body 3 comes to a position immediately in front of the support member 17, so that the insertion rod 6 is prevented from bending. further,
On the return path after the completion of the fuel rod insertion, the support members 17, 1 follow the movement of the retracting operation member 22 after the insertion rod driving body 11 has passed.
The insertion rod 6 is gripped again by moving 7 to the insertion rod 6 side.

[0018]

As described above, according to the present invention, a pair of left and right supports that are movable in a direction orthogonal to the insertion axis of the insertion rod and in a direction away from each other and are always urged toward each other. A plurality of insertion rod support seats configured by tools are arranged at a predetermined interval along the movement path of the insertion rod, and the pair of left and right supports support the insertion rod from both sides thereof, and the insertion rod is attached to the insertion rod support seat. Since the insertion rod driving body is provided with a retracting operation member for moving the supporting members in the expanding and retracting direction when the insertion rod driving body approaches the insertion rod supporting seat, the insertion rod driving body is Only when passing through the support seat part, the left and right support members are separated from each other and retracted, and the insertion rod driving body can be freely moved.
At other times, the insertion rod is always gripped and supported by the insertion rod support seat, and the bending of the insertion rod can be reliably prevented. Therefore, the fuel assembly can be automatically assembled by the nuclear fuel assembly assembly system, and the structure thereof is simple and does not require highly accurate control or complicated structure, and the device cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a fuel assembly apparatus of the present invention.

FIG. 2 is an enlarged perspective view of an insertion rod support seat portion and a retracting operation member portion in FIG.

FIG. 3 is a diagram showing a schematic configuration of a conventional fuel assembly apparatus.

[Explanation of symbols]

1 Nuclear fuel assembly device body 2 Slide guide 3 Insert rod driver 4 drive motor 6 insertion rod 7 Spacer 8 Lower tie plate 9 fuel rods 11 Insert rod support seat 12 Support seat mounting member 13 Slide bearing 14 Support seat support member 15 Extension spring 17 Support 18 ball bearings 19 Notch recess 21 Retraction actuating member 22 Information

Claims (5)

(57) [Claims] 1. A nuclear fuel assembly apparatus having a fuel rod inserting mechanism for inserting a fuel rod into a cell of a spacer and into a lower tie plate by an inserting rod which moves in the axial direction and rotates around the axial line. A plurality of insertion rod support seats arranged at predetermined intervals along the movement path of the movable rods are movable toward or away from each other in the direction orthogonal to the insertion axis of the insertion rod, and are always biased toward each other. It is composed of a pair of left and right supporting tools, and the insertion rod is supported from both sides by the pair of left and right supporting tools, and the insertion rod driving body is attached to the insertion rod driving body to which the insertion rod is attached. An apparatus for assembling a nuclear fuel assembly, characterized in that a retraction actuating member is provided for moving the support members in the expanding and retracting direction when approaching the support seat. 2. A pair of left and right supports is provided along the insertion rod.
On the horizontal part formed on the supporting seat mounting member
It is movably mounted perpendicular to the direction of the axis, connecting the are supported by a pair of right and left support seat support member which is biased approaching direction to each other, and the support seat support member supporting member
The nuclear fuel assembly device according to claim 1, wherein a pair of left and right shafts that are connected to each other are provided with ball bearings that engage with the retracting operation member. 3. A pair of left and right support members are provided with a notch recess having a triangular cross section on the surfaces facing each other, and a ball bearing for engaging an insertion rod is provided on the inner surface of the notch recess. The nuclear fuel assembly assembly device according to claim 1 or 2, wherein 4. The retracting operation member has a width narrowing toward the tip thereof, and by its movement, engages with a ball bearing provided on a shaft connecting the support seat supporting member and the supporting tool, and The nuclear fuel assembly device according to any one of claims 1 to 3, characterized in that a guide portion is formed to move the fuel element in a direction away from each other. 5. The nuclear fuel assembly apparatus according to claim 2, wherein the support seat support members are supported by slide bearings and are urged toward each other by springs.