JPH0426436B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that can remotely attach, detach, and clean large bolts, and particularly relates to a device that can be suitably used for stud bolts in nuclear reactor pressure vessels.

As shown in Figure 1, the reactor pressure vessel has an upper mirror 1.
and the body 2 are connected by stud bolts 3 and nuts 4, so that the entire pressure vessel is hermetically sealed. FIG. 2 shows details of the connection using stud bolts. The stud bolt 3 is connected to the flange 2a of the body 2 by a threaded portion 3a of the stud bolt 3, protrudes from its upper surface, passes through a through hole 1b formed in the upper mirror flange portion 1a, and has a threaded portion 3b at the other end. It protrudes above the upper mirror flange 1a.
A nut 4 is attached to this threaded portion 3b, and its tightening force connects the upper mirror 1 and the body 2 with the stud bolt 3. A large number of stud bolts 3 are arranged so that the nuts 4 almost touch each other in the circumferential direction of the upper mirror flange 1a. For this reason, the nut 4 has a cylindrical shape and is configured to rotate through a groove 4a formed at its upper end.

In the reactor pressure vessel, the upper mirror 1 is opened and closed during annual periodic inspections for fuel exchange, and the stud bolts are loosened and tightened using a stud tensioner as shown in Figure 3. . In this figure, the stud tensioner 5 is suspended by a chain block 8 from an annular rail 7 attached to a tensioner frame 6 fixed to the upper mirror 1. A worker approaches the upper mirror 1 and manually sets it to the stashed bolt 3. In addition, the stud bolts 3 are so close that the nuts 4 that tighten them are in contact with each other, and the stud tensioner 5 is suspended by the chain 8a and swings, so the worker must directly manually stop the stud tensioner from swinging. The center alignment with the stud bolt 3 is performed visually by the worker.

On the other hand, the chain block 8 that suspends the stud tensioner 5 can only move in the circumferential direction of the upper mirror 1 along the rail 7 that is circumferentially attached to the tensioner frame 6. When the stud bolt 3 is misaligned in the radial direction of the upper mirror, aligning the stud bolt 3 requires a worker to push the stud tensioner 3 laterally, which is labor-intensive and dangerous.

As described above, with conventional equipment, workers work close to the reactor pressure vessel and directly touch equipment in a high radiation area, which poses the problem of radioactive contamination of the human body.

The present invention suspends stud tensioners, bolt cleaners, and nut runners used in the top cover opening/closing work performed during periodic inspections of reactor pressure vessels, etc., and allows these devices to be operated remotely without the need for workers to approach the reactor pressure vessel. An object of the present invention is to provide a device configured to be able to operate.

In short, this invention provides an apparatus for cleaning and tightening stud bolts which connect a pressure vessel body and an upper mirror by a flange and are arranged annularly at approximately the same pitch on the flange. A station with a plurality of swing drive devices that move independently, a truck with a front and rear drive device that is attached to each station and moves independently in the radial direction of the track, and a bolt cleaner that is suspended from the truck and can be raised and lowered individually. A stud tensioner with a position detector and a bolt runner are placed corresponding to the circumferential pitch of the stud bolt, and the amount of misalignment detected by the position detector is calculated as the amount of displacement in the orbit circumferential direction and radial direction to control displacement. and a remote automatic control panel for controlling the operations of each of the devices.

Embodiments of the present invention will be described below with reference to the drawings.

In Figures 4 to 6, 9 is a supporting leg;
0 is a planar annular track supported by support legs 9, and is fixed to a fixing part formed on the upper lid 1 of the pressure vessel with a pin or the like. Reference numeral 11 denotes a station that moves in the circumferential direction of the upper mirror 1 along this orbit 10 by a rotation drive device 12. station 11
A cart 13 is mounted on the upper mirror 1 and is moved in the diametrical direction of the upper mirror 1 by a longitudinal drive device 14. An elevating drive device 15 is attached to this truck, and a bolt cleaner 17, stud tensioner 5, and nut runner 18 are each suspended via an elevating arm 16. Each lifting arm 16 is
They are arranged to have the same pitch as the stud bolts 3, and by aligning the stud tensioner 5 and the stud bolts 3, the bolt cleaner 17 and nut runner 18 are also arranged so that their centers align with the respective stud bolts 3. There is.
19 is a detector for detecting the relative position of the stud bolt 3 and the stud tensioner 5;
The stud tensioner 5 is attached near the lower end of the stud tensioner 5, which is suspended from the stud tensioner 5, in two directions so that its axes are perpendicular to each other within the same plane. Reference numeral 20 denotes an operation panel for remotely controlling the above-mentioned equipment, and also for controlling the detector 1.
The relative position of the stud tensioner 5 and stud bolt 3 detected by 9 is calculated as the amount of misalignment in the rotation direction and radial direction of the station 11, and is fed back to the rotation drive device 12 and longitudinal drive device 14 of the station 11 to adjust the stud tensioner 5 and the stud bolt 3. Tensiona 5
The misalignment of the stud bolt 3 is corrected.

In FIGS. 7 and 8, 21a is a wheel for supporting the weight of the station 11, stud tensioner 5, bolt cleaner 17, and nut runner 18, and for smoothly rotating the station 11. It moves on a rail 22a attached to the top surface of the. 21b and 21c are
These are guide wheels for supporting the rotational moment generated by the overhang structure of the station 11 and for smoothly driving the station 11 in turning.Like the wheels 21a, the rails 22b and 22b are attached to the inner and outer surfaces of the track 10. 22c. These guide wheels 21a, 21
b and 21c are each attached at two locations in the circumferential direction of the track 10 in order to maintain balance in the width direction of the station 11 (in FIG. 7, the upper and lower sides of the figure). Reference numeral 12 denotes the above-mentioned swing drive device, which is located at the center of the width direction of the station 11, and is connected to the drive motor 12 as shown in FIG.
a, reducer 12b, pinion 12c and rack 1
Consists of 2d. Here, the rack 12d is fixed to the upper surface of the track 10. 13 is orbit 1
The carriage is a carriage that moves in the radial direction of the station 11, is supported by a bearing 23 attached to its lower surface, and moves along a guide 24 fixed to the station 11. The truck 13 is driven by a front-rear drive device 14, and by rotating a threaded rotating shaft 14a, a drive nut 14b that engages with the rotating shaft 14a and is attached to the lower surface of the truck 13 moves in the axial direction of the rotating shaft 14a. By being moved, it moves in the radial direction of the track 10. Reference numeral 15 denotes an elevating drive device, which drives the elevating arm 16 in the vertical direction via a worm reducer 15a.

The operation of the apparatus configured as above will be explained below. In the case of opening the upper mirror, first, as shown in Fig. 4, the station 11, stud tensioner 5,
The track 10 to which the bolt cleaner 17 and nut runner 18 are attached is attached to the upper mirror 1 using a crane or the like, and the support legs 9 and the upper mirror 1 are fixed with pins or the like. Next, drive the swing drive device 12 of the station 11 to move it to a desired position of the bolt 3. First, drive the lift drive device 14 that suspends the stud tensioner 5, and move it near the lower end of the stud tensioner 5. The stud tensioner 5 is lowered until the attached detector 19 hooks onto the head of the stud bolt 3. After the descent is completed, the detector 19 is activated to detect the relative alignment between the stud tensioner 5 and the stud bolt 3, and the amount of misalignment determined by the remote automatic control panel 20 is sent to the rotation drive device 12 of the station 11.
Then, the stud tensioner 5 and the stud bolt are aligned by providing feedback to the longitudinal drive device 14. After the alignment is completed, the elevating drive devices 15 of the stud tensioner 5, bolt cleaner 17, and nut runner 18 are driven, and each device is set on its respective stud bolt, and each operation is performed. After the work is completed, drive the lifting drive device 15 again,
Each device is lifted up and the swing drive device 12 is driven to move the station to the next bolt position. Repeat the above operations to open the upper mirror. All of the above operations are performed remotely and automatically using a remote automatic control panel in an area with low radiation levels.

By implementing the present invention, stud bolts can be attached, removed, and cleaned by remote control, so there is no risk of worker exposure to radiation, and since no manual work is required, the amount of labor required for the work is greatly reduced. can do.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the connection between the reactor pressure vessel body and the upper mirror, Fig. 2 is a sectional view showing details of section A in Fig. 1, and Fig. 3 is a side view of a stud bolt tightening device according to the prior art. 4 is a plan view of the bolt tightening device according to the present invention, FIG. 5 is a side view of the same device, FIG. 6 is a perspective view of section B in FIG. 4, and FIG. 7 is the station shown in FIG. 4. A plan view showing details of the state in which the
9 is a sectional view taken along the line D--D in FIG. 7. 1... Upper mirror, 3... Stud bolt, 4... Nut, 5... Stud tensioner, 10... Track, 11... Station, 12... Turning drive device, 13... Trolley, 14... Front and rear drive device, 17
...Bolt cleaner, 18...Natsutranna, 1
9...Position detector.

Claims (1)

[Claims] 1. In a device that connects the pressure vessel body and the upper mirror through a flange, and cleans and tightens the stud bolts arranged annularly at approximately the same pitch on the flange, an annular track attached to the upper mirror and this track are moved independently. A station with multiple swing drive devices, a truck with a front and rear drive device attached to each station that moves independently in the radial direction of the track, a bolt cleaner that is suspended from this truck and can be raised and lowered individually, and a position detector. A stud tensioner and a bolt runner are arranged corresponding to the circumferential pitch of the stud bolt, and the amount of misalignment detected by the position detector is calculated as the amount of displacement in the circumferential direction of the orbit and in the radial direction, and the displacement is controlled. A bolt cleaning and tightening device comprising a remote automatic control panel that controls the operation of each device.