JPH01146604A - Cutting device for inside of tube plate - Google Patents

Abstract

PURPOSE:To accurately feed a cutter and to reliably secure a device body to the tube plate side, by a method wherein the elevating speed of a cylindrical body is varied in a plurality of steps by a drive force transmission means, and the device body having a clamp capable of being secured in the hole of a tube plate is secured to the tube plate. CONSTITUTION:A device body 31 is positioned in the position of a fine tube 1 to be cut by means of a manipulator, a piston cylinder 46 is raised, and a cotter 45 is inserted in the fine tube 1. A taper shaft 47 is raised, the cotter 45 is secured on the inner surface of the fine tube 1, and air is fed through an air feed hole (h) to adhere the device body 31 to a tube plate 2. A gear 41 is rotated through a gear 40 and a harmonic drive 42 with the aid of a feed motor 34, and an intermediate shaft 43 is rotated through a gear 44 or 45. A moving table 37 is raised through a ball screw device 48, and a cutter 16 is inserted in the fine tube 1. Simultaneously, a motor 33 for cutting is run, and the cutter 16 is rotated through gears 54 and 50, a spline shaft 49, a ball spline device 51, gears 52 and 53, and a cutter shaft 39 to cut a plug 3 for removal.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cutting device for removing repair plugs from steam generator capillaries in nuclear reactor plants.

<Prior Art> A steam generator of a nuclear reactor plant has a thin tube for exchanging heat between secondary cooling water and secondary cooling water, and plug repair is performed to repair this thin tube.

FIG. 6 shows the state of plug repair.

The thin tube 1 is fixed to a tube plate 2, and a plug 3 is driven into the thin tube 1 to prevent primary cooling water from entering the thin tube 1.

The procedure for removing the plug 3 is shown in FIGS. 7 to 9. 7th
As shown in the figure, a guide hole 4 is formed in the center of the plug 3 using a hole-hole tool.

Using the guide hole 4 as a guide, insert the plug 3 using a plug cutting tool.
8. Remove the caulked portion 5 (as shown in FIG. 8). The guide hole 4 is threaded, and as shown in FIG. 9, the plug 3 is removed by screwing the extraction rod 6 into the threaded portion and pulling it out in the direction of the arrow.

As described above, the purpose of the plug cutting tool is to process the plug into the state shown in FIG. 8, and FIG. 5 shows a conventional pipe interior cutting device for plug cutting.

This device is fixed to a capillary tube 1 embedded in a tube plate 2 by a clamp cylinder 7, and a torque reaction force is also supported by a steady rest device (not shown) using another capillary tube 1. A support stand 8 is provided at the bottom of the clamp cylinder 7.
are connected to each other, and a hydraulic cylinder 9 is fixed to the support base 8. A gear box 11 is connected to the tip of the piston shaft 10 of the hydraulic cylinder 9, and a groove is machined in the axial direction on the outer periphery of the gear box 11. A rail 12 is formed on the clamp cylinder 7, and a gear box 1 is formed on the rail 12.
1 groove is slidably fitted.

That is, the gear box 11 moves up and down along the rail 12 due to the vertical movement of the piston shaft 10 caused by the drive of the hydraulic cylinder 9 .

A cutter mounting shaft 13 is rotatably supported within the gear box 11 via a radial bearing, and the cutter mounting shaft 13 is rotationally driven by a drive gear 15 of an air motor 14 .

A cutter 16 is fitted and fixed on the cutter mounting shaft 13, and the cutter 16 is covered with a bellows device 17. The bellows device 17 is attached to the gear box 11 by a rod 18 and a spring 19.

The hydraulic cylinder 9 is provided with ports a and b, and the port a
When water pressure is applied to the gear box 11 , the gear box 11 rises, and the fitting 20 provided on the top surface of the bellows device 17 comes into contact with the bottom surface of the tube plate 2 . When the stopper fitting 20 comes into contact with the tube plate 2, the cutter 16 is inserted into the thin tube 1, as shown by the two-dot chain line in FIG. , the cutter 16 rotates to cut the plug 3. The feed speed of the cutter 16 is adjusted by a needle valve 21 connected to the hole 1-b.

The gear box 11 is provided with a port C2d, cutting fluid is supplied from the port C, and the cutting fluid is supplied to the port d together with chips.
is discharged from.

<Problems to be Solved by the Invention> In the conventional pipe interior cutting device described above, the cutter 16 is fed by the hydraulic cylinder 9, and the feed rate of the cutter 16 is adjusted by the needle valve 21, so the feed rate is not constant. There was a problem that it could not be controlled accurately. Further, since the pipe interior cutting device was fixed to the tube plate 2 side only by the cylinder force of the clamp cylinder 7, the fixing force was unstable.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a tube interior cutting device for a tube sheet in which the cutter can be accurately fed and securely fixed to the tube sheet side.

Means for Solving Problems> The structure of the present invention for achieving the above object includes a device main body having a clamp that can be fixed in a hole in a tube sheet and to which a frame body is integrally connected; a cylindrical body provided in a frame body so as to be movable up and down; an elevating drive source provided on the frame body for driving the cylindrical body up and down; and an elevating drive source disposed between the elevating drive source and the cylindrical body. a driving force transmitting means that changes the driving force of the source in multiple stages and transmits the driving force as the vertical movement of the cylindrical body; a tool rotation shaft that is rotatably supported within the cylindrical body; It is characterized by comprising a rotational drive device that rotationally drives a tool rotation shaft, and a cutting tool that is detachably attached to the tip of the tool rotation shaft.

Function: The device body is fixed to the tube plate side by fixing the clamp in the hole. The cylindrical body is moved up and down by the drive of the elevating drive source via the driving force transmitting means, and the elevating speed during cutting, when pulling out the cutting tool, etc. is changed by the driving force transmitting means.

A cutting tool is attached to the tip of the tool rotation shaft, and the rotation drive device rotates the tool rotation shaft to rotate the cutting tool to perform cutting inside the pipe.

Embodiment> FIG. 1 shows a cross-sectional side view of a tube interior cutting device for a tube sheet according to an embodiment of the present invention, FIG. 2 shows a view taken along the line ■-■ in FIG. 1, and FIG. 1[-N line arrow view in FIG. 2, and FIG. 4 shows the It/-It/ line arrow view in FIG. 3. Components that are the same as those shown in FIG. 5 are given the same reference numerals, and redundant explanations will be omitted.

A frame body 32 is integrally connected to the apparatus main body 31, and the apparatus main body 31 is provided with a cutting motor 33, a feed motor 34 as an elevating drive source, and an upper support base 35. A rail 36 extending in the vertical direction is provided within the frame 32, and a movable table 37 is slidably fitted into the rail 36. A spindle 38 as a cylindrical body is fixed to the moving table 37, and a cutter shaft 39 as a tool rotation axis is attached to the spindle 38.
is rotatably supported. A cutter 16 as a cutting tool is removably fitted onto the cutter shaft 39 .

A gear 40.41 is provided on the drive shaft of the feed motor 34, and a harmonic drive 42 is provided in the middle of the gear 40.41.
are arranged. The rotation of gear 40 is transmitted to gear 41 via an oct-monic drive 42 at a speed of several tens of minutes. The optimum value of this reduction ratio is selected depending on the object to be cut, the type of cutter 16, etc. The device body 31 has an intermediate shaft 4.
3 is rotatably supported, and the intermediate shaft 43 has a gear 40.4.
Gears 44, 45 meshing with 1 are provided. gear 4
A clutch 46 is provided in the middle of 4° 45, and the clutch 46 transmits the rotational force transmitted to either of the gears 44 and 45 to the intermediate shaft 43. That is, by switching the clutch 46, the intermediate shaft 43 can rotate at high speed or at low speed. On the other hand, a ball screw shaft 47 is rotatably supported by the frame 32 , and the ball screw shaft 47 is connected to the intermediate shaft 43 . The ball screw device 4 is attached to the ball screw shaft 47.
8 are screwed together, and the ball screw device 48 is fixed to the movable table 37. That is, as the ball screw shaft 47 rotates due to the rotation of the intermediate shaft 43, the movable table 37 moves up and down along the rail 36 via the ball screw device 48. The above gear 40
, 41, eight-monic drive 42, intermediate shaft 43, gears 44, 45, clutch 46, ball screw shaft 47, and ball screw device 48 constitute a driving force transmission means.

A spline shaft 49 is rotatably supported on the frame 32.
A gear 50 is fixed to the top of the spline shaft 49. A ball spline device 5 is installed at the bottom of the spline shaft 49.
The ball spline device 51 is rotatably supported by the movable table 37. A gear 52 is attached to the ball spline device 51, and the gear 52 is connected to the gear 5 attached to the cutter shaft 39.
It meshes with 3. On the other hand, a cutting motor 33 is provided on the frame 32, and a drive gear 54 of the cutting motor 33 meshes with the gear 50. That is, the spline shaft 49 is rotated by the drive of the cutting motor 33 via the drive gear 54 and the gear 50, and the ball spline device 51 and the gear 52 are rotated.
The cutter shaft 39 rotates through .degree.53. The cutting motor 33, the spline shaft 49, the gear 50, the ball spline device 51, the gears 52 and 53, and the drive gear 54 constitute a rotary drive device.

A clamp device 55 as a clamp is provided on the upper support base 35 in accordance with the pitch of the thin tube 1.
5 is fixed to the tube plate 2 to fix the device main body 31 to the tube plate 2 and to cope with the reaction force during cutting.

The clamp device 55 will be explained based on FIGS. 2 to 4.

The rod 45 is supported by being divided into three parts by an external piston cylinder 46 (see FIG. 4), and the rod 45 is pressed against the inner surface of the thin tube 1 by movement of the tapered shaft 47 and supports the device main body 31 (see FIG. 3). . As shown in FIG. 2, the clamp groups fi 55 are arranged at four locations around the cutter 16 in accordance with the pitch of the thin tubes l.

When fixing the device body 31 to the tube plate 2, the device body 31 is positioned at the position of the thin tube to be cut using a manipulator (not shown). The air supply hole e (see Fig. 3) is vented to retract the taper shaft 47, the air supply hole f (see Fig. 3) is vented to raise the piston cylinder 46, and the kotsuta 45 is inserted into the thin tube 1. insert. The air supply is switched from the air supply hole e to the air supply hole g (see FIG. 3), and the taper shaft 47 is raised to fix the cotter 45 to the inner surface of the thin tube 1 (the state shown in FIG. 3). When all the clamp devices 55 are fixed, the air supply is switched from the air supply hole f to the air supply hole h (see FIG. 3), and the device main body 31 is lifted up to bring the device main body 31 into close contact with the tube plate. Therefore, even if the manipulator is removed, the device main body 31 can be held in close contact with the tube plate 2.

Driven by the feed motor 34, the gear 41 is rotated via the gear 40 and the harmonic drive 42, and the intermediate shaft 43 is rotated via the gear 44 or the gear 45. The rotation of the intermediate shaft 43 causes the ball screw shaft 47 to rotate, and the movable table 37 is raised along the rail 36 via the ball screw device 48, so that the cutter 16 is inserted into the thin tube 1. At this time, the cutting motor 33 is simultaneously driven, and the drive gear 54 and the gear 5 are
The cutter shaft 39 is rotated via the 01 spline shaft 49, the ball spline device 51, and the gears 52 and 53 to rotate the cutter 1.
Rotate 6. The plug 3 is cut and removed by rotating the cutter 16.

Since the gear 40 rotates at a high speed and the gear 41 rotates at a low speed, the rotation of the gear 44 or the gear 45 is selected by switching the clutch 46 and transmitted to the intermediate shaft 43, thereby controlling the feed of the moving table 37. The speed can be selected to be fast or slow. Therefore, the moving table 37 is moved at low speed only during cutting.
By moving the , cutting can be performed efficiently and reliably.

Note that the operating circuit, interlock circuit, and monitoring circuit necessary for operating the feed mechanism, rotation (cutting) mechanism, and clamp mechanism of the cutter 16 can be implemented using conventionally known configurations such as limit switches and Hall ICs. Explanation will be omitted. Furthermore, by changing the type of the cutter 16, it can be applied to cutting the thin tube 1, cutting off the sleeve, and cutting off the welding plug.

Since the cutting device described above mechanically feeds the cutter 16, the feed speed can be kept constant and accurately controlled.
By switching the clutch 46, the feed speed of the cutter 16 can be selected in two stages. Further, since the clamp device 55 itself is fixed to the thin tube 1, it is not necessary to occupy the manipulator that holds the device body 31.

<Effects of the Invention> The tube interior cutting device for a tube sheet of the present invention is capable of changing the lifting speed of the cylindrical body in multiple stages using the driving force transmission means, so that the cutting tool can be fed optimally and accurately. Moreover, not only can cutting be performed reliably, but also the cutting tool can be fed efficiently. Further, since a clamp that can be fixed in the hole of the tube sheet is provided, the device main body can be temporarily fixed to the tube by the device itself, and the device can be securely fixed to the tube sheet side.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a tube interior cutting device for a tube sheet according to an embodiment of the present invention, and FIG. 2 is a view taken along the line II-[ in FIG.
Fig. 3 is a view taken along the line I-I in Fig. 2, Fig. 4 is a view taken along the line IV-1ull in Fig. 3, and Fig. 5 is a cross-sectional side view of a conventional tube interior cutting device for tube sheets. , FIGS. 6 to 9 are cross-sectional views of the capillary showing the procedure for removing the plug. In the drawing, 1 is a thin tube, 2 is a tube plate, 16 is a cutter, 31 is the device body, 32 is a frame, 33 is a cutting motor, 34) a feed motor, 37 is a moving table, 43 is an intermediate shaft, 46 is a clutch, 47 is a ball screw shaft, 48 is a ball screw device, 49 is a spline shaft, 51 is a ball spline device, and 55 is a clamp device.

Claims (1)

[Claims] A device main body having a clamp that can be fixed in a hole in a tube plate and to which a frame body is integrally connected, a cylindrical body provided in the frame body so as to be movable up and down, and the cylindrical body provided in the frame body. an elevating drive source for elevating and lowering the cylindrical body; and a driving force that is disposed between the elevating drive source and the cylindrical body and that changes the driving force of the elevating drive source in a plurality of stages and transmits the driving force as the elevating movement of the cylindrical body. a transmission means, a tool rotation shaft rotatably supported within the cylindrical body, a rotation drive device provided on the frame body for rotationally driving the tool rotation shaft, and a rotation drive device that is detachably attached to the tip of the tool rotation shaft. A cutting device for cutting inside a tube of a tube sheet, comprising: a cutting tool attached thereto;