JP3332754B2 - Large pressure vessel lid mounting hole drilling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus,
In particular, the present invention relates to an apparatus for performing post-installation processing of a large pressure vessel such as a nuclear reactor vessel.

[0002]

2. Description of the Related Art In a large-sized plant facility or the like, if a problem occurs after the installation of the facility is completed and the service is started, the place is repaired and the service is continued. For example, a reactor vessel of a pressurized water nuclear power plant is a large-sized pressure vessel, and includes a vessel main body having an upper mounting flange, and a vessel lid or a top lid having a joining flange fastened on the mounting flange. In the case of repairing a stud hole into which a stud bolt for tightening the upper lid is screwed, the repair is performed by attaching a processing tool to the processing portion while keeping the container body as it is. This will be briefly described with reference to FIG.
In the thick cylindrical portion 3 surrounding the upper opening of the reactor vessel main body 1, a plurality of stud holes 5 are formed at a predetermined circumferential pitch, and a stud bolt screw is formed on the inner surface thereof. Have been. In order to rework the stud hole 5 due to a defect, the flange 7 with the upper lid removed is used.
The frame 9 of the gate-type machine tool is placed on the
The cutting tool 13 is inserted into the stud hole 5 by the spindle head 11 that moves up and down along the axis, and rotates.

[0003]

However, the conventional processing apparatus as described above has the following problems. That is, the reactor vessel is a large vessel and the stud hole has a considerably large diameter. Therefore, it is necessary to rigidly fix the machine tool in order to accurately perform the inner diameter machining and the screw machining, but the upper lid mounting surface including the upper surface of the flange 7 is not so wide and the shape is appropriately fixed. It was extremely difficult to achieve. In order to realize this fixing, various auxiliary members and the like are required, and much time is required for these fixing operations. In addition, since the inside of the reactor vessel is activated especially by use, the processing work with the upper lid removed is in a high radiation atmosphere, so there are various restrictions for maintaining the health of workers, Also, measures were needed. From this point of view, a special device is required for the tool replacement work because the tool itself becomes large. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lid mounting hole processing apparatus for a large-sized pressure vessel that can easily realize high-rigidity fixing when reworking the lid-mounted hole of a large-sized pressure vessel.

[0004]

According to the present invention, in order to solve the above-mentioned problems, according to the present invention, a container body having a thick cylindrical portion for mounting a lid and a top surface of the thick cylindrical portion are fastened and attached. A large-pressure vessel lid mounting hole processing apparatus for re-machining the mounting hole of the thick-walled cylindrical portion of the large-sized pressure vessel including the upper lid having the joining flange is inserted into the plurality of mounting holes of the joining flange, respectively. A plurality of gripping mechanisms, a base plate interconnecting the upper ends of the gripping mechanisms, and a gripping mechanism which is inserted between the joining flange and the upper surface of the thick cylindrical portion and gripped by the tip of the gripping mechanism. Gripping structure comprising a clamp plate, an upright column having a support structure fixed on the base plate of the gripping structure, a spindle head portion supported up and down by the upright column, and the upright column Provided in Serial is connected to the main shaft head portion combined with the feed mechanism and the main shaft of the spindle head unit composed of the spindle arbor machining tool is attached to the tip. In the present invention described above, since the upper lid of a large pressure vessel is generally large and heavy, this weight is skillfully used for rigidly fixing the processing apparatus.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIG. 1, FIG. 1 shows a joining flange 15 of the reactor vessel main body 1 and its upper lid 13.
1 shows the overall structure of the processing apparatus 20 mounted above. As can be seen from the figure, the stud hole 5 of the thick cylindrical portion 3 of the reactor vessel body 1 and the stud bolt insertion hole 17 of the joining flange 15 are aligned. During normal operation of the reactor, a stud bolt is screwed and fixed into the stud hole 5 as easily supposed, and a fixing nut screwed onto the upper end of the stud bolt is tightened, and the upper lid 13 is fixed to the reactor vessel main body. 1 to form a pressure vessel. The processing device 20 has a gripping structure 30 in order to securely fix the processing device 20 to the reactor vessel main body 1 and the upper lid 13 as described above. The holding structure 30 is inserted between the base plate 31 placed on the upper surface of the joining flange 15, the holding mechanism 33 passed through the stud bolt insertion hole 17, and the joining flange 15 and the thick cylindrical portion 15. It has a clamp plate 35, and its detailed structure will be described later. The lower support structure 5 of the upright column 50 is placed on the base plate 31.
1 is fixed. The upright column 50 is a guide rail 5
3. Ascending / descending assistance of a column 55 standing upright, a pulley 57 provided at the upper end of the column 55, a wire rope 59 wound around the pulley 57, a load reducing cylinder 61 connected to the wire rope 59, and the like. Has a mechanism. A spindle head 70 having a sliding carriage guided by the guide rail 53 is arranged at the center of the upright column 50, and a feed mechanism 130 is provided above the spindle head. In addition, stud hole 5
The machining tool 21 inserted in is connected to the main shaft of the main spindle head 70 via the main shaft arbor 23.

The guide rail 53 has a rail 63 as shown in FIG.
A sliding carriage 73 guided by the rail 63 is attached to the first carriage 1. A spindle head 75 of the spindle head unit 70 is attached to a lifting table 71 via a fulcrum shaft 77 so as to be able to swing in a horizontal direction, and is fixed to an operating position by a fixing bolt 79 during a machining operation.

FIGS. 3 and 4 show the detailed structure of the feed mechanism 130. FIG. 3 and 4, the screw shaft 131 of the feed mechanism 130 penetrating the elevating table 71 is mounted on the frame structure 65 of the upright column 50 by bearings 133, 135.
It is rotatably supported via. Frame structure 65
The output shaft of the spindle feed motor 137 provided at the upper end of
The screw shaft 131 is connected to the screw shaft 131 via the gear reduction unit 139, and is rotationally driven as described later.
5 is braked by a brake 141 provided on the motor. The screw shaft 131 is formed with a screw on the upper outer periphery corresponding to the elevating stroke of the spindle head unit 70, and details of a connection portion with the spindle head unit 70 using the screw are particularly shown in FIG. I have. In FIG. 4, a gear case 81 fixed to a lifting table 71 is closed by a lid 82, and a nut 84 is fixed to a spur gear 83 rotatably supported around a screw shaft 131 inside the gear case 81. The nut 84 is screwed onto the screw shaft 131, and when the screw shaft 131 rotates,
If the rotation of the nut 84 is restricted, the nut 84 moves up and down to feed the lifting table 71. Further, the amateur side of the clutch 85 is a nut 84
, While the rotor side is connected to the lid 82. The intermediate shaft 87 of the spindle head 70 extending parallel to the screw shaft 131 is supported by the casing at upper and lower ends by bearings 88 and 89, and a spur gear 91 fitted to the intermediate shaft 87 is connected to a spur gear 83 on the screw shaft 131 side. And are engaged. The armature side of a clutch 92 provided surrounding the lower portion of the intermediate shaft 87 is connected to a spur gear 93 rotatably fitted to the intermediate shaft 87, while the rotor side receives the intermediate shaft 87 and is connected to a casing side. Fixed. The spur gear 93 is adapted to mesh with a spur gear 96 provided on the main shaft 95.

The spindle head 7 including the spindle 95 described above.
5 is shown in FIG. In FIG. 5, a main shaft 95 having a hollow structure is provided with bearings 98, 9 on a casing 97.
9, 101, and a lower end of the spindle arbor 23
Are formed in the tapered hole 103 for receiving the hole.
A tightening rod 105 is inserted and fixed in the main shaft 95, and this is a male screw structure 1 that projects into the tapered hole 103.
07. The spindle arbor 23 receives a thrust, a bending load, or the like as a cutting resistance. In order to support the thrust or bending load, a thrust bearing 109 is provided around the lower end of the spindle 95 so as to surround the tapered hole 103. On the other hand, casing 9
The output shaft of the main shaft rotating motor 111 installed on the upper surface of the helical gear 121 is mounted on the main shaft 95 via a reduction gear train 119 mainly including helical gears including the intermediate shafts 113 and 115. And the rotational driving force of the spindle rotating motor 111 can be transmitted to the spindle 95 at a large reduction ratio.

FIG. 6 shows a detailed structure of the gripping mechanism 33 of the gripping structure 30 described above. In FIG. 6, the gripping mechanism 33 includes a cylindrical upper structure 37 connected to the base plate 31 and a lower structure 4 having a clamp piston 39.
1 and a gripping disk 45 is provided at the tip of a cylinder rod 43 extending from the clamp piston 39. In order to set such a gripping structure 30, the stud bolt insertion hole 17 of the joining flange 15 of the upper lid 13 is aligned with the stud hole 5 of the reactor vessel main body 1, and the lower surface of the joining flange 15 is thickened. The upper lid 13 is suspended and held by appropriately holding the gap 16 with the upper surface of the meat cylindrical portion 3.
Then, the gripping mechanism 33 of the gripping structure 30 is inserted as illustrated, the clamp plate 35 is inserted between the gaps 16, and fitted to the outside of the cylinder rod 43 as illustrated. Then, when the upper lid 13 is lowered, the clamp plate 35 is securely sandwiched between the joining flange 15 and the thick cylindrical portion 3. Thereafter, the gripping disk 33 is held by the gripping mechanism 33.
By pulling in the direction of lifting, the gripping structure 30 is securely fixed to the joining flange 15 of the upper lid 13. When the lower support structure 51 of the upright column 50 is mounted on the base plate 31 after fixing the holding structure 30 in this manner, the state shown in FIG. 1 is obtained.

The mounting of the gripping structure 30 is performed as described above, but the center of the spindle head 75 on the upright column 50 fixed thereon is not aligned with the stud hole 5 to be repaired or reworked. Therefore, the gripping structure 30 is provided with a centering mechanism 47 as shown in FIG. The centering mechanism 47 includes a cylindrical upper structure 48 connected to the base plate 31 and a lower structure 49 having a built-in cylinder structure.
In and out horizontally. In this way, the outer peripheral surface of the claw 44 is brought into contact with the inner peripheral surface of the stud hole 5 to perform centering. Such centering operation is performed prior to the lifting operation of the clamp plate 35 by the gripping mechanism 33 described above.

The operation of the above-described processing apparatus 20 will be described. To feed the spindle head 70, the spindle feed motor 137 of the feed mechanism 130 is driven to operate the clutch 85. When the spindle feed motor 137 rotates in this way, the screw shaft 131 rotates, and the nut 84 screwed to the screw shaft 131 rotates.
Is not rotated by the clutch 85, and therefore moves in the vertical direction, the elevating table 71 moves and the spindle head 70 is fed. When the spindle head unit 70 is to be fed upward, the load on the spindle feed motor 137 is reduced by activating a lifting / lowering auxiliary mechanism such as the load reducing cylinder 61. When rotating only the main shaft 95, the clutch 85
, And the main shaft rotating motor 111 is rotated while the clutch 92 and the brake 141 are inoperative. The rotational force of the main shaft rotation motor 111 is transmitted to the main shaft 95 via the reduction gear train 119, and causes the main shaft 95 and the main shaft arbor 23 connected to rotate.

Further, when preparing a pre-drilled hole in the stud hole 5, an inner surface cutting tool is attached to the spindle arbor 23 as the machining tool 21, and the clutch 85 is maintained in an operating state, and the clutch 92 and the brake 14 are maintained in an inoperative state. Feed motor 1
37 and the spindle rotation motor 111 are rotated. Since this state is a combination of the rotation and the feed of the spindle 95 described above, the feed is given to the spindle head 70 where the spindle 95 is rotating, and the spindle arbor 23 that rotates with the spindle 95.
And the machining tool 21 moves in the axial direction in the stud hole 5 to machine the pilot hole. In order to further thread the inner surface of the stud hole 5, a spindle arbor 23 to which a suitable cutting tool such as a cutting tool is attached as the machining tool 21 is fitted to the spindle 95. Then, the clutch 85 is deactivated and the clutch 92 is turned off.
And the brake 141 to the operating state, and the spindle rotating motor 1
Rotate 11 By doing so, the spindle rotating motor 1
11, the main shaft 95 is rotated as described above, but the screw shaft 131 is stopped by the brake 141. on the other hand,
Due to the operation of the clutch 92, the rotation of the main shaft 95 is controlled by the intermediate shaft 87.
Through the nut 84. That is, since the nut 84 rotates and the spindle head 70 is fed at a constant rate with respect to the rotation of the spindle 95, the inner surface of the stud hole 5 is threaded.

As described above, when preparing and threading the stud hole 5, it is necessary to change the processing tool 21. In the processing apparatus 20, the processing is performed as follows. That is, as shown in FIG. 8, a lid integrated structure 14 for supporting a control rod driving device and the like is provided above the current upper lid 13, and a rail 18 and a hoist 19 for lifting stud bolts and the like when the lid is removed are provided. By using this, the spindle arbor 23 to which the predetermined machining tool 21 is attached is moved and moved up and down. Further, at this time, the fixing bolt 79 is removed as shown by a two-dot chain line in FIG. 2, and the spindle head 75 is pivoted forward about the fulcrum shaft 77.
In this way, the spindle arbor 23 suspended from the hoist 19 is moved to the mounting position without being disturbed by the spindle head 75, and can be easily fitted to the spindle 95.

[0014]

As described above, according to the present invention,
Since the gripping structure is fixed to the upper lid that is originally attached to the large pressure vessel and the processing equipment is attached, the processing equipment that reprocesses the lid mounting hole of the container body can be easily fixed firmly. it can. Further, during the processing operation, since the opening of the vessel body is almost completely closed by the original upper lid, it is possible to prevent processing chips and the like from falling into the vessel body. In the case of (1), the radiation from the inside of the container is effectively shielded, so that the working environment can be kept safe.

[Brief description of the drawings]

FIG. 1 is an elevation view showing the entire structure of an embodiment of the present invention.

FIG. 2 is a plan view corresponding to FIG.

FIG. 3 is a partially omitted vertical sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a partially enlarged view of a portion IV in FIG. 3;

FIG. 5 is a partial sectional view of another portion of FIG. 1;

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 1;

FIG. 7 is a partial sectional view of still another part of FIG. 1;

FIG. 8 is an operation explanatory view of the embodiment.

FIG. 9 is a partial elevational view showing a conventional processing state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor vessel main body 3 Thick cylinder part 5 Stud hole 7 Flange 13 Upper lid 15 Joining flange 17 Stud bolt insertion hole 20 Processing device 30 Grasping structure 31 Base plate 33 Grasping mechanism 35 Clamp plate 37 Upper structure 39 Clamp piston 41 Lower part Structure 43 Cylinder rod 44 Claw 45 Gripping disk 46 Tapered structure 47 Centering mechanism 48 Upper mechanism 49 Lower mechanism 50 Upright column 51 Lower support structure 53 Guide rail 55 Strut 57 Pulley 59 Wire rope 61 Load reducing cylinder 63 Rail 65 Frame structure 70 Main shaft head 71 Elevating table 73 Sliding carriage 75 Main shaft head 77 Support shaft 79 Fixing bolt 81 Gear case 82 Lid 83 Spur gear 84 Nut 85 Clutch 87 Intermediate shaft 88, 89 Bearing 91 Spur gear 9 Clutch 93 Spur gear 95 Main shaft 96 Spur gear 97 Casing 98,99,101 Bearing part 103 Tapered hole 105 Tightening rod 107 Male screw structure 109 Thrust bearing part 111 Main shaft rotation motor 113,115 Intermediate shaft 119 Reduction gear train 121 Helical gear 130 feed mechanism 131 screw shaft 133, 135 bearing unit 137 main shaft feed motor 139 gear reduction unit 141 brake

Continuation of the front page (72) Inventor Nobuo Yasumatsu 1-1-1, Wadazakicho, Hyogo-ku, Kobe-city, Hyogo Prefecture Inside Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Shinji Takahashi Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo Prefecture 1-1-1 1-1 Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Hidekazu Inui 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Prefecture Examiner, Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (56) References JP-A-8-262181 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G21C 19/02 G21C 13/00

Claims (1)

(57) [Claims] 1. The thick wall of a large-sized pressure vessel comprising a container main body having a thick cylindrical portion for attaching a lid and an upper lid having a joining flange fastened and attached to an upper surface of the thick cylindrical portion. An apparatus for reworking a mounting hole of a cylindrical portion, comprising: a plurality of gripping mechanisms respectively inserted into the plurality of mounting holes of the joining flange; a base plate interconnecting upper ends of the gripping mechanisms; A gripping structure composed of a clamp plate inserted between a thick-walled cylindrical portion and the joining flange and gripped at a tip end of the gripping mechanism; an upright having a support structure fixed on the base plate A column, a spindle head portion supported on the upright column so as to be able to move up and down, a feed mechanism provided at an upper portion of the upright column and combined with the spindle head portion, and a machining tool at a tip connected to the spindle of the spindle head portion. The lid mounting hole machining apparatus of large pressure vessels, characterized by comprising a spindle arbor eclipsed.