JPH0473758B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a top cover opening/closing device for a nuclear reactor pressure vessel, and in particular to a nuclear reactor pressure vessel top lid opening/closing device that completely automates the work on stud bolts and nuts for fixing the top cover. This invention relates to a top lid opening/closing device for a furnace pressure vessel.

[Prior Art] In general, a nuclear reactor pressure vessel has a structure as shown in Fig. 9.
It is composed of a pressure vessel body body a with an open top and a top cover b covering the top, and is screwed from a top cover flange c to a body body flange d, and has a stud bolt e protruding upward from the top cover flange c. By tightening a nut g onto the exposed threaded portion f, the upper cover b is fixed to the trunk body a. As shown in FIG. 10, a large number of stud bolts e are arranged in the circumferential direction of the flanges c and d so as to be able to sufficiently withstand the internal pressure of the pressure vessel. Further, the stud bolt e and the nut g tightened thereon weigh approximately 250 kg and 20 kg, respectively.

Incidentally, in nuclear reactor equipment, work is performed to remove the top cover b from the shell body a and to attach it to the shell body a for periodic inspections and the like. Specifically, prior to removing the nut g, the threaded part f of the stud bolt e is cleaned to make it easier to remove the nut g, and then the stud bolt e is pulled upward with the stud tension, and in that state, the nut is removed. Loosen g. Then, remove the nut g from the stud bolt e and move it onto the workbench. Furthermore, loosen stud bolt e and remove stud bolt e from barrel body flange d. By performing the above steps,
Preparations for removing the top cover b from the trunk body a are now complete. Further, when attaching the upper cover b to the trunk body a, the procedure is reversed.

[Problems to be solved by the invention] (1) In the conventional work, work other than tensioning the stud bolt e by the stud tensioner, that is, cleaning the stud bolt e and tightening and loosening the nut g. , their installation, removal, and movement, and the installation and removal of stud bolts e, etc., rely on many hands, and the work is extremely hard considering the number and weight of stud bolts e and nuts g, and the work requires a long time. The work involved a lot of radiation exposure and required a lot of time.

(2) Since the pedestal for lifting the top cover was provided via a hanging bracket provided on the top cover b that had a large installation error, the pitch circle of the stud bolt e and the center of the stud tensioner did not match accurately. Therefore, it was necessary to adjust the centering each time when working on each stud bolt e.

(3) It is desired to make effective use of the narrow operating floor by using both the top lid lifting frame and the rotary table frame that supports the stud tensioner.

[Means for Solving the Problems] The present invention includes a fixed pedestal that is transported by a crane and installed on the upper cover of a reactor pressure vessel by pin connection, and a fixed pedestal that is rotatably and radially movably supported on the fixed pedestal. A sensor detects the misalignment between the rotary table and the pitch circle of the stud bolt installed on the top cover, and a sensor that supports the inner circumference of the rotary table and moves in the radial direction to correct the misalignment. an elevating frame having a centering roller, a tracing device provided at appropriate intervals in the circumferential direction of the rotary table and moving up and down following the stud bolts; a bolt cleaning device, a bolt tightening and loosening device, and a stud bolt provided on the elevating frame; Tensiona,
It is characterized by being equipped with a nut attaching/detaching device and a nut conveying device.

[Function] To describe the function of the present invention, the entire structure is lifted by a fixed frame connected by pins,
In addition, centering rollers center the rotary table so that it is concentric with the pitch circle of the stud bolt, and the lifting frame equipped with a bolt cleaning device, bolt tightening and loosening device, etc. is moved up and down.
By guiding with a copying device that imitates the stud bolt, the lifting frame can be raised and lowered easily and accurately, and the bolt cleaning device etc. can be reliably guided to the stud bolt that is the target of work, and furthermore, it can be installed all at once on the lifting frame. The work has been completely automated using a bolt cleaning device, a bolt tightening/loosening device, a stud tensioner, a nut attaching/detaching device, and a nut conveying device.

[Embodiment] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figures 1 and 2, above the top cover 1 that covers the upper part of the reactor pressure vessel shell body (not shown), there is a structure that functions as a hanging structure when the top cover 1 is removed and moved. A fixed pedestal 2 consisting of a circular frame structure is transported by a crane and installed by pin connection. This pedestal 2 is provided with a hanging hardware 4 hung on a crane hook 3 on its central upper surface, and the pedestal 2 is suspended and transported by a crane via this hanging hardware 4. Moreover, this pedestal 2 has a lower surface on its circumferential side that allows the upper lid 1 to be attached to the pedestal 2 when the upper lid 1 is moved.
A turnbuckle-like joint member 6 is provided which is connected to a joint end 5 provided on the top cover 1 for downward suspension support. Furthermore, expandable and contractible radial rollers 8 for centering are provided radially in the central cylindrical portion of this pedestal 2, and these rollers 8 are extended and contracted from the central cylindrical portion by turnbuckles 10, and the rolling of the rotary table 11 is By being pressed against the surface 19, it is possible to correct the misalignment of the rotary table 11 with respect to the pitch circle of the stud bolt 9 set on the upper cover 1. A pillar 100 is vertically attached to the lower surface of the rotary table 11, and the lower end of the pillar 100 is attached to the rotary table 1 by measuring the gap between it and the stud bolt 9.
A sensor 101 is provided to detect the amount of misalignment between the stud bolt 9 and the pitch circle of the stud bolt 9.
Also, a roller support frame 2 supporting the roller 8 is provided.
0 is provided with a pinion 17 that meshes with an annular internal gear 16 provided on the inner circumference of the rotary table 11, and this pinion 17 is equipped with a motor 18 with a reduction gear mounted on a roller support frame 20. The pinion 17 is driven by the motor 18, and the rotary table 11 is rotated around the pedestal 2.

An annular rotating table 11 that is rotatably driven along the circumferential direction of the upper lid flange 7 above the upper lid 1 is provided on the outer peripheral side of the fixed pedestal 2 configured in this manner. This rotary table 11 has a mount 2.
A thrust roller 14 is disposed along the circumferential direction of the pedestal 2 to engage with a rail 12 formed on a horizontal portion of the periphery of the pedestal 2. and rotary table 11
is rotatably supported on the pedestal 2 by rollers 14 that engage with the rails 12. Further, the rotary table 11 is controlled so as to be driven within a range of 90° for each pitch of the stud bolts 9 set on the upper lid flange 7.

The rotary table 11 configured in this way has the following features:
Four elevating frames 21 are provided along the circumferential direction at 90° intervals. This lifting frame 2
1 is connected to both ends along the circumferential direction of the upper lid flange 7 with a set of extending/retracting means 22 such as a set of screws and a hydraulic cylinder that are vertically installed from the rotary table 11. It is suspended and supported on the 7 side so that it can be raised and lowered. In particular, these telescoping means 22 are
1 and the elevating frame 21, and the elevating frame 21 is swingably supported under the rotary table 11. This allows for slight movement of the lifting frame 21 due to the copying operation of the lifting frame 21 by the copying device 23, which will be described later, and distortion of the upper surface of the upper cover flange 7 when the bolt cleaning device 24 etc. is grounded on the upper cover flange 7. This is the configuration for

Each of the elevating frames 21 configured in this manner includes a copying device 23 that imitates the stud bolts 9 installed in the upper cover 1 in order to guide their elevating movement, and a copying device 23 that imitates the stud bolts 9 and nuts 25 that are the object of the elevating frame 21. Bolt cleaning device 2 for performing work
4. A bolt tightening/loosening device 26, a stud tensioner 27, a nut attaching/detaching device 28, and a nut conveying device 29 are provided all at once. As shown, a bolt cleaning device 24 and a bolt tightening/loosening device 2 are shown.
6. Stud tensioner 27 and nut attachment/detachment device 2
8 are integrally assembled, respectively, and a bolt cleaning device 24, a stud tensioner 27, and a nut conveying device 29 are sequentially arranged along the direction of rotation of the rotary table 11.

Next, the individual devices will be explained.

First, as shown in FIGS. 1 and 3 to 5, the copying device 23 mainly includes a sleeve body 30 that is suspended from the lifting frame 21 and has an inner diameter that surrounds the stud bolt 9. Sleeve body 3
0 and a copying roller 31 rotatably provided. The sleeve body 30 is the elevating frame 21
As the stud bolt 9 descends, it is inserted deeper into the stud bolt 9 in the axial direction. Further, the copying rollers 31 are arranged at 90° intervals so as to surround the stud bolt 9 from the outside in the radial direction.
Further, a pair of upper and lower bolts are provided at a considerable distance in the axial direction of the stud bolt 9. And this copying device 2
3, when the elevating frame 21 is lowered, the sleeve body 30 is inserted into the stud bolt 9 and the copying roller 31 runs on the outer peripheral surface of the stud bolt 9 in the axial direction, so that its movement is restricted by the stud bolt 9. The vertical movement of the lifting frame 21 is adjusted and guided from the sleeve body 30 side. Thereby, the bolt cleaning device 24 and the like disposed on the elevating frame 21 are guided to the stud bolt 9 to be worked on. At this time, the position of the elevating frame 21 is
1 may move slightly from the stopped position, but this can be absorbed by the swinging of the elevating frame 21 due to the attachment of the above-mentioned telescopic means 22. Further, between the bolt cleaning device 24 and the stud tensioner 27, an auxiliary roller 32 is supported by one of these via a bracket or the like.
will be provided. These auxiliary rollers 32 are attached to the top cover flange 7 in a radial direction so as to sandwich the stud bolts 9 and are deflected by 45 degrees with respect to the copying roller 31. And these auxiliary rollers 3
2 travels along the axial direction on the outer peripheral surface of the stud bolt 9 which is separated from the copying roller 31 by a considerable distance as the lifting frame 21 descends, and the lifting frame 21 swings in the radial direction of the upper cover flange 7. The copying accuracy of the copying roller 31 is improved by regulating the amount of paper.

Next, the bolt cleaning device 24 installed all at once
The bolt tightening and loosening device 26 will be explained. The bolt cleaning device 24 cleans the threaded portion of the stud bolt 9 that was exposed before removing the nut 25 before removing the top cover 1, and cleans the threaded portion of the stud bolt 9 on the other side.
This is to clean the threading surface of the nut 25 before threading it onto the stud bolt 9 during installation. Further, the bolt tightening and loosening device 26 is used to remove stud bolts 9 screwed from the upper lid flange 7 to the trunk flange when removing the upper lid 1 from the trunk body, and when attaching the upper lid 1 to the trunk body. , for screwing the stud bolt 9 onto the body flange.

As shown in FIGS. 1, 2, and 6, a lifting frame 21 that moves up and down along the axial direction of the stud bolt 9 is provided with a bolt cleaning device 24 and a bolt cleaning device 24 at its lower part via a support frame 33. A loosening device 26 is provided.

The bolt tightening and loosening device 26 is mainly attached to the lifting frame 21 via the support frame 33, and is used to detachably engage the stud bolt 9 and tighten and loosen the stud bolt 9 to attach and detach it from the body flange. It is composed of a rotating rod 34 that is rotationally driven. More specifically, the rotating rod 34 is formed in the shape of a hollow shaft extending downwardly from the support frame 33 side to the upper lid flange 7 side, and the rotating rod 34 is formed in the shape of a hollow shaft extending downwardly from the support frame 33 side, and the support frame 33 surrounding it from the outside in the radial direction connects the peripheral side thereof. It is rotatably supported by the support frame 33 by a bearing member 35 provided therebetween. A gear 36 is formed on the upper end of the rotating rod 34 on the support frame 33 side, and a wrench portion 37 is formed on the lower end of the rotating rod 34 on the upper lid flange 7 side.
is formed. A pinion 39 connected to a motor 38 mounted on the support frame 33 and capable of rotating forward and backward is meshed with the gear 36, and the rotating rod 34 is rotationally driven by the motor 38. Further, the wrench portion 37 is removably engaged with an engagement recess 40 formed on the top surface of the stud bolt 9 as the elevating frame 21 moves up and down, and transmits the rotational force of the rotary rod 34 to the stud bolt 9. It's getting old. The rotary rod 34 rotates the stud bolt 9 by its rotational drive, thereby tightening and loosening the stud bolt 9 with respect to the upper cover flange 7 and the body flange. On the other hand, a lifting rod 41 for lifting the stud bolt 9 upward when loosening the stud bolt 9 is rotatably inserted into the hollow portion of the rotating rod 34 along the axial direction. This salvage rod 4
1 has an upper end connected to a motor 42 for rotationally driving the same, and a male screw portion 43 formed at a lower end. This male threaded portion 43 is screwed into a female threaded portion 44 formed in the center of the engagement recess 40 on the top surface of the stud bolt 9 when the lifting rod 41 is rotationally driven by the motor 42, and the lifting rod 41 is rotated by the motor 42. 41
is adapted to engage with the stud bolt 9. The lifting rod 41 is connected to the stud bolt 9 and lifts the elevating frame 21, thereby applying the lifting force to the stud bolt 9 as a pulling force to assist in the loosening operation. In addition, these rods 34, 41
The springs 45, 46, 47 mounted in the axial direction of
It functions to absorb the impact when these rods 34, 41 and stud bolt 9 are engaged.

On the other hand, the bolt cleaning device 24 mainly includes a cylindrical housing 48 that is attached to the lifting frame 21 via the support frame 33 and seals and covers the stud bolt 9 from the outside in the radial direction of the rotary rod 34. The cleaning means 49 is rotatably provided in the housing 48 in contact with the outer peripheral surface of the stud bolt 9, and is rotatably driven coaxially with the rotary rod 34. The housing 48 covers the stud bolt 9 between the support frame 33 and the upper surface of the upper lid flange 7, and functions to prevent dust generated during cleaning by the sweeping means 49 from scattering. Further, the sweeping means 49 includes a brush portion 5 that comes in contact with the outer circumferential surface of the stud bolt 9 and sweeps it away.
0 and a back frame 51 spline-fitted along the axial direction of the stud bolt 9 on the back surface of the brush portion 50, and the sweeping means 49 is a bearing provided between the back frame 51 and the housing 48. The member 52 is rotatably supported within the housing 48 . A gear 53 is formed on the inner wall side of the housing 48 in the back frame 51, and a gear train 55 connected to a motor 54 supported by the housing 48 and capable of rotating in forward and backward directions is meshed with the gear 53. is this motor 54
The stud bolt 9 is rotated by the stud bolt 9. In particular, the brush portion 50 is spline-fitted to the back frame 51 and configured to be movable up and down along the axial direction of the stud bolt 9.
When the nut 25 is screwed into the stud bolt 9, the exposed part above the nut 25 is cleaned, and when the nut 25 is removed, it falls under its own weight and the part where the nut 25 was screwed is cleaned. It's summery.

In particular, the bolt cleaning device 24 and the bolt tightening/loosening device 26 are configured such that a housing 48 is provided outside the rotary rod 34, and a sweeping means 49 is disposed coaxially with the rotary rod 34 so as to be rotationally driven. , it is possible to assemble them all at once, which saves space.
It is possible to achieve a reduction in work time. Further, the work of tightening and loosening the stud bolt 9 can be automated, and the conventional manual work can be abolished.

Next, the stud tensioner 27 and nut attaching/detaching device 28 that are assembled together will be explained.

The stud tensioner 27 applies tension to the stud bolt 9 when tightening or loosening the nut 25 to the stud bolt 9.
This is to reduce the torque required to secure or loosen the tightening force of the nut 25. Further, the nut attaching/detaching device 28 is used to further remove the loosened nut 25 to the top of the stud bolt 9 using the stud tensioner 27, or to remove the nut 25 from the top of the stud bolt 9 when tightening the nut 25 to the stud bolt 9. This is for screwing into the upper lid flange 7 side.

As shown in FIGS. 1, 2, and 7, the lifting frame 21 is provided with a stud tensioner 27 and a nut attaching/detaching device 28 hanging therefrom.

The stud tension 27 has a general configuration,
Mainly, the elevating frame 2
A grip part 60 is formed at the lower end to grip the top of the stud bolt 9, and a hydraulic piston 61 is formed at the upper end.
The sleeve body 63 is formed with an engaging flange 62 that engages with the sleeve body 63, and a hydraulic piston 61 that presses the engaging flange 62 of the sleeve body 63 upward.
The sleeve body 63 is moved by the hydraulic piston 61 by hydraulic pressure.
is designed to apply tension to the stud bolt 9 by pushing it upward. Further, the tensioner housing 59 is provided with a nut rotation means 64 that engages with and rotates the nut 25 in order to move the nut 25 along the axial direction of the stud bolt 9 in order to tighten and loosen the nut 25 on the stud bolt 9. It will be done. The nut rotating means 64 includes a socket 66 that is provided coaxially with the stud bolt 9 in the tensioner housing 59 and engages with an engaging step 65 formed on the upper surface of the nut 25, and a socket 66 on the circumferential side of the socket 66. It is comprised of a gear train 68 that meshes with the formed gear 67, and a motor 69 that is connected to the gear train 68 and drives it, which can freely rotate in forward and reverse directions. The nut rotating means 64 rotates the socket 66 with a motor 69 to tighten and loosen the nut 25 on the stud bolt 9. On the other hand, the tensioner housing 59 has a nut rotating means 64 provided therein to constitute the nut attaching/detaching device 28 in order to move it in synchronization with the movement of the nut 25 along the axial direction of the stud bolt 9. Moving means 7 such as a screwdriver or hydraulic cylinder for moving the tensioner housing 59
0 is set. The moving means 70 has one end attached to the elevating frame 21 and the other end attached to the tensioner housing 59 to move the tensioner housing 59 up and down relative to the elevating frame 21. First, the nut 25 is loosened by the nut rotation means 64 using the stud tensioner 27, and after the tension is released, the nut rotation means 64 is operated and the tensioner housing is moved by the movement means 70 in synchronization with the movement of the nut 25. By raising 59,
The nut 25 can be removed to the top of the stud bolt 9. Tightening of the nut 25 is performed in the reverse order. With this configuration, the nut 25 can be easily and automatically attached and detached from the stud bolt 9.

Next, the nut conveying device 29 will be explained.

The nut conveying device 29 transports the nut 25 loosened to the top of the stud bolt 9 by the nut attaching/detaching device 28 from the top cover flange 7 when the top cover 1 is opened, and also transfers the nut 25 to the stud bolt 9 when the top cover 1 is closed. It is intended to be transported to the top of the building. As shown in FIGS. 1, 3, and 4, the nut conveying device 29 is disposed close to the stud tensioner 27 and offset radially outward of the upper cover 1. The nut conveying device 29 mainly includes a base frame 71 that is moved up and down from the lifting frame 21 side to the upper lid flange 7 side, and one end attached to the sleeve body 30 of the above-mentioned copying device 23 and the other end attached to the base frame 71. A drive means 72 such as a screw jack or a hydraulic cylinder that is vertically installed and expands and contracts to move the base frame 71 up and down, and an upper lid flange 7 on the base frame 71.
a slider 73 that is slidably provided inward in the radial direction of the upper lid 1 from the outside to scoop up the nut 25; and this slider 73 and the base frame 71.
a screwdriver installed between the base frame 71 and the base frame 71 to move the slider 73 forward and backward from the base frame 71 toward the stud bolt 9 side;
It is composed of an actuating means 74 such as a hydraulic cylinder. The base frame 71 is provided with a sliding plate 76 that engages with a rail 75 formed along the depth direction of the sleeve body 30.
The base frame 71 is the rail 7 of the sleeve body 30.
5 to be guided up and down. Further, the slider 73 is movably engaged with a pair of guide rods 77 arranged in parallel along the radial direction of the upper lid flange 7 on the base frame 71, and is guided by these guide rods 77 to advance and retreat. A U-shaped scooping part 78 that surrounds the stud bolt 9 from the outside in the radial direction is formed at the tip end of the slider 73 facing the stud bolt 9, and as shown in FIG. The nut 25 is inserted into the nut 25 from below by rising the base frame 71.
It has become like scooping up. Also scooping part 78
A magnet 80 is provided on the lower surface of the nut 25 to attract the washer 79 installed between the nut 25 and the upper lid flange 7 in order to remove the washer 79. The washer 79 is attracted by the magnet 80 by once lowering the base frame 71. This nut conveying device 29 scoops up the nut 25 and the washer 79 by the raising/lowering movement of the base frame 71 and the forward/backward movement of the slider 73 by the driving means 72 and the actuating means 74, and scoops up the nut 25 and the washer 79 from the deck 81 provided adjacent to the upper cover 1. Upper base 8
2, these nuts and washers 79 are carried out.

Next, the operation of the embodiment will be described.

When removing the upper cover 1 of the reactor pressure vessel, first use a crane to move the fixed frame 2 to the rotary table 11.
The fixed pedestal 2 is placed on the top lid 1 by pin connection. Next, the sensor 101
The amount of misalignment of the rotary table 11 with respect to the pitch circle of the stud bolt 9 is detected, and the centering roller 8 corrects the misalignment of the rotary table 11. Next, the rotary table 11 is rotated around the stand 2 one pitch at a time on the stud bolts 9 within a range of 90 degrees, and the various devices installed in the four elevating frames 21 are used to rotate the stud bolts 9 and nuts 25 one by one. The work will be carried out. When the elevating frame 21 is lowered by the telescopic means 22, the copying device 2
3 is moved along the stud bolt 9 set on the upper cover 1, and then the elevating frame 21 is lowered following the stud bolt 9. This copying device 2
3, the bolt cleaning device 24 and the like are accurately guided to the stud bolt 9, which is the work target. By the lowering movement of the elevating frame 21, the bolt cleaning device 24 and stud tensioner 27 are deeply attached to the stud bolt 9.

In the following, operations for one set of stud bolts 9 and nuts 25 will be explained in chronological order.

First, the stud bolt 9 is cleaned by the bolt cleaning device 24. The bolt cleaning device 24 cleans the nut 25 of the stud bolt 9 because its sweeping means 49 is located on the nut 25.
Clean the exposed areas above. The sweeping means 49 is driven by a motor 54 to rotate around the stud bolt 9, and cleans the outer peripheral surface of the stud bolt 9 with its brush portion 50. As a result, when removing the nut 25 afterwards,
Rotation of the nut 25 relative to the stud bolt 9 can be facilitated.

Once the stud bolt 9 has been cleaned in this way, the bolt cleaning device 24 is separated from the stud bolt 9 by raising the lifting frame 21, and then the rotary table 11 is rotated by one pitch of the stud bolt 9, and then the lifting frame 21 is moved up and down. 21 is lowered again and this time the stud tensioner 27 is attached to the stud bolt 9. Stud tensioner 2
7 applies tension to the stud bolt 9 and loosens the nut 25 by the nut rotating means 64. When the nut 25 can be rotated easily in this way, the tension by the stud tensioner 27 is released. Thereafter, the nut rotating means 64 of the nut attaching/detaching means 28 is driven again, and the nut 25 is further loosened to the top of the stud bolt 9.
Remove from. At this time, the tensioner housing 59 supporting the nut rotating means 64 is moved by the moving means 70.
By raising the nut 25 in synchronization with the axial movement of the nut 25, the nut 25 can be automatically and easily raised.
5 can be removed from the stud bolt 9.

In this way, attach the nut 25 to the stud bolt 9.
After the nut 25 is removed from the nut 25, the nut 25 is then carried out onto the deck 81 by the nut conveying means 29. In this case, first, the base frame 71 is lowered by the driving means 72 to an appropriate position lower than the position of the nut 25, and then the slider 73 is advanced toward the stud bolt 9 by the actuating means 74. Next, the base frame 71 is lowered once and the washer 79 is attracted by the magnet 80, and then the base frame 71 is raised and the scooping part 78 picks up the nut 2.
Scoop up 5. Thereafter, the slider 73 is moved back to position the scooping part 78 above the base 82 of the deck 81, and finally the base frame 71 is lowered to carry out the nuts 25 and the like onto the deck 81.

By performing these operations, all the nuts 25 and the like are removed from the top cover flange 7.

Next, the rotary table 11, which has completed its rotation within the 90° range, is rotated in the opposite direction, and the stud bolt 9 is removed from the body flange by the bolt tightening/loosening device 26. When the lifting frame 21 is lowered as described above, the bolt tightening/loosening device 26 is deeply attached to the stud bolt 9. First, the lifting rod 41 is screwed into the female threaded portion 44 on the top surface of the stud bolt 9, and then the wrench portion 37 of the rotary rod 34 is engaged with the engagement recess 40 of the stud bolt 9. The bolt tightening and loosening device 26 is
The stud bolts 9 can be sequentially removed from the body flange toward the upper cover flange 7 by rotating the stud bolts 9 using the rotary rod 34 while applying a pulling force to the stud bolts 9 via the lifting rod 41 using the lifting force of the lifting frame 21. It's becoming like that.

The above operations are performed on all the stud bolts 9 and nuts 25, and the top cover 1 is removed from the main body. Furthermore, when attaching the top cover 1,
The above operations are performed in substantially the opposite order. Therefore, when the top cover 1 is attached, the stud bolt 9 is cleaned by the bolt cleaning device 24 immediately after the stud bolt 9 is screwed into the body flange by the bolt tightening/loosening device 26.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) By using a fixed frame as the frame for lifting the top lid and the frame for the rotary table, lifting the top lid and lifting the device, which were previously done separately, can now be done at the same time. This makes it possible to reduce labor and work time.

(2) The bolt cleaning device, bolt tightening/loosening device, stud tensioner, nut attaching/detaching device, and nut conveying device all installed on the lifting frame can perform multiple functions such as cleaning stud bolts, tightening/loosening nuts, and studding nuts. Attachment and removal from bolts, loading and unloading of nuts, and tightening and loosening of stud bolts can be performed continuously and automatically, resulting in labor saving and shortening of working time.

(3) After installing the fixed frame on the top cover, a sensor detects the misalignment of the pitch circle of the stud bolt,
By correcting this misalignment, we centered the rotary table and guided the vertical movement of the lifting frame equipped with various devices using a mechanical tracing device that imitates stud bolts, resulting in a simple structure. The elevating frame can be raised and lowered with high precision and the various devices can be reliably guided to the stud bolt to be worked on.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a preferred embodiment of the present invention;
Fig. 2 is a plan view thereof, Fig. 3 is a side view showing the copying device and nut conveying device adopted in the present invention, Fig. 4 is a plan view thereof, and Fig. 5 is a schematic plan view showing the copying state by the copying device. Fig. 6 is a side sectional view showing a bolt cleaning device and bolt tightening/loosening device which are incorporated in the present invention, and Fig. 7 is a stud tension device which is incorporated in the present invention. FIG. 8 is a schematic front sectional view showing how the nut is scooped up by the nut conveying device; FIG. 9 is a side view showing the general top cover mounting structure; FIG. 10 is its plan view. In the figure, 1 is an upper lid, 2 is a fixed frame, 8 is a centering roller, 9 is a stud bolt, 11 is a rotary table, 21 is a lifting frame, 23 is a copying device, 24
26 is a bolt cleaning device, 26 is a bolt tightening and loosening device,
27 is a stud tensioner, 28 is a nut attaching/detaching device, and 29 is a nut conveying device.

Claims (1)

[Claims] 1. A fixed pedestal carried by a crane and installed on the top cover of the reactor pressure vessel by pin connection, a rotating table supported rotatably and movably in the radial direction on the fixed pedestal, and a fixed pedestal mounted on the rotating table and the top cover. A sensor detects the misalignment between the pitch circle of the stud bolt, a centering roller supports the inner periphery of the rotary table and moves it in the radial direction to correct the misalignment, and A lifting frame having a copying device provided at intervals and moving up and down following stud bolts, and a bolt cleaning device, a bolt tightening/loosening device, a stud tensioner, a nut attaching/detaching device, and a nut transporting device provided on the lifting frame. A top lid opening/closing device for a nuclear reactor pressure vessel, characterized by: