JPH022643B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for cutting the inner surface of a main steam isolation valve in a nuclear power generation device.

Currently, one or more main steam isolation valves c are installed between the reactor pressure vessel a side and the turbine b side in nuclear power generation equipment, etc., as shown in Figure 1, to ensure safety. has been done. As shown in Fig. 2, this main steam isolation valve c integrally has three parts: an inflow side passage body d, an outflow side passage body e, and a valve insert body f. The valve body h is configured to move toward and away from the rear end side of a valve seat g provided in the middle and on the front end side of the latter f to open and close the valve, and the valve body h is configured to open and close the valve. teeth,
As shown in FIG. 3, the stellite alloy i is welded to ensure that the valve remains airtight.

However, as the use of this main steam isolation valve became longer,
When the valve is repeatedly opened and closed, the stellite alloy i welded to the circumferential surface wears out, and there is a problem in that the valve may leak due to malfunction. There is a way to deal with this problem by repairing the valve seat g before malfunction due to wear occurs, but conventionally, the isolation valve itself is large and the valve seat g The work is difficult because it is located deep inside the body f, and even if the work is carried out, it is difficult to maintain the high accuracy of the valve seat g surface.

In view of the above points, the present invention proposes a main steam isolation valve inner surface cutting device used in the cutting process of the remaining stellite alloy that is part of the above repair work and the surface processing process after welding a new alloy. The purpose of this invention is to promote automation of the process operations and to improve their accuracy.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings from FIG. A cylindrical body 3 of the device main body 2 is inserted so as to be freely slidable in the axial direction, and a gear case 4 is fixed to the rear end of the cylindrical body 3. Reference numeral 5 designates a screw shaft that is installed in the gear case 4, and has a male threaded end portion screwed into a female threaded hole in the collar 1a, and is connected to a third motor 8 in the gear case 4 to be rotated. As a result, the device main body 2 consisting of the cylinder 3, gear case 4, etc. slides in the axial direction relative to the outer cylinder 1, and the outer cylinder 1 is fixed to the inner surface of the valve insert body f as described later. When the body f
It will now slide in the axial direction. A cylindrical shaft 9 is rotatably supported within the cylindrical body 3 via bearings 10, 10, and is connected to the first motor 6 within the gear case 4 for rotation. An annular face plate 11 is fixed to the tip of the cylindrical shaft 9, and four tool holders 12, which are slidable approximately in the radial direction, are attached to the end face of the annular face plate 11 in an equidistant manner. One cutting tool 13 is attached to each of the outer peripheries of the tips of the tools 12 . A small cylindrical body 14 is attached to the center of the tip of the cylindrical shaft 9, and a television camera 15 with a lens directed in the radial direction is fixed to the tip of the small cylindrical body 14. Reference numeral 16 denotes a small-diameter shaft that is installed in the cylindrical shaft 9 and whose tip is slidably inserted into the small cylindrical body 14, and a shaft hole 16a for wiring from the television camera 15 to the gear case 4 is bored. The rotary joint 17 is arranged at the rear end. The small diameter shaft 16 is connected to the first motor 6 in the gear case 4 and rotated synchronously with the cylindrical shaft 9.
It is connected to the motor 7 to be rotated independently, and further connected to the third motor 8 to be slid in the axial direction. As mentioned above, the third motor 8 is also connected to the screw shaft 5, but the connection to the small diameter shaft 16 and the connection to the screw shaft 5 are made by a clutch device (not shown) in the gear case 4. shall be selectively connected.

Further, on the outer peripheral surface of the small cylinder 14, a circumferential groove 18 is formed as shown clearly in FIG. A U-shaped member 20 fixed to the outer peripheral surface of the tip of the small diameter shaft 16 is slidably engaged with the shaft 19 . A groove 21 continuous to the circumferential groove 18 is formed in the U-shaped member 20 . 22...
is a support shaft 11 fixed to the inner surface of the annular face plate 11;
These are four arms that rotate around center a, and are arranged in four pieces corresponding to the positions of the tool holders 12. The arm 22 has two support arms 22a and 22b that protrude at a substantially right angle, and one support arm 22a is engaged with the rear end recess of the corresponding tool holder 12, and the other support arm 22b is engaged with the rear end recess of the corresponding tool holder 12. is engaged with the circumferential groove 18 or groove 21, and rotates only in the direction indicated by arrow A in the figure. 23 is the byte 1
3. It is an illumination lamp that emits light, has an annular shape, and is fixed to the tip of the cylindrical body 3.

Reference numerals 24 and 24 denote a centering mechanism provided on the outer circumferential surface of the outer cylinder 1, which includes a tapered member 25 fixed to the outer cylinder 1 in the axial direction, and an adjustment part having a lock bolt 27 at the rear end. The width in the radial direction can be changed by adjusting the facing position of the tapered member 26 which has a tapered member 26 and can freely slide in the axial direction. The centering mechanisms 24, 24, as shown in FIG.
It is provided at two locations in the circumferential direction of the outer peripheral surface. 28
Similar to the centering mechanisms 24, 24, the outer cylinder 1
It is a clamping device provided on the outer peripheral surface of the seventh
As shown in the figure, the inner end of the protrusion 31, which is slidable in the radial direction, engages with the tapered part 29a of the slide member 29, which has an adjustment part with a locking bolt 30 arranged at the rear end and is slidable in the axial direction. It matches. Two sets of the slide member 29 and the protruding piece 31 are provided in the clamp device 28 .

Next, each operating mechanism of the inner surface cutting device having the above-mentioned configuration will be explained by system as follows.

(A) Centering of the device with respect to the body f
The tapered member 26 of each centering mechanism 24, 24 is slid by operating each adjustment section, thereby adjusting the opposing position with the opposing tapered member 25 to change the width in the radial direction. At the same time, the clamping device 28 also slides the slide member 29 in the axial direction by operating each adjustment section, adjusts the engagement position with the protrusion 31, and changes the protrusion length of the protrusion 31 in the radial direction.

(B) Axial sliding of the device main body 2 Connect the third motor 8 to the screw shaft 5 by operating the clutch device (not shown),
Rotate this.

(C) Adjusting the diameter of the tool holder 12 By operating the clutch device (not shown), the third motor 8 is connected to the small diameter shaft 16, and this is slid in the axial direction. Then, the small diameter shaft 16
One arm 2 engaged with a U-shaped member 20 at the tip
2 rotates in the direction A in the figure, and one tool holder 12 corresponding to the arm 22 slides in the radial direction. Total of 4 bite holders 12...
‥ is selectively subject to the above operations,
The selection of the tool holder 12 is performed by the second motor 7.
by rotating only the small diameter shaft 16,
The support arm 22b of any arm 22 is engaged with the U-shaped member 20. At this time, the remaining three arms 2
The support arm 22b of 2... is the U-shaped member 20.
The circumferential groove 18 of the small cylinder body 14 is wider than the groove 21 of
It's within.

(D) Rotation of the cutting tool 13 The first motor 6 causes the small diameter shaft 16 and the cylindrical shaft 9 to rotate synchronously.

Next, the method of using the device having the above configuration and operating for each system will be explained as follows.

(a) First, measure the dimensions of the body f to be cut using the device, and confirm the origin for axial sliding of the device main body 2 and diameter adjustment of the cutting tool holder 12.

(b) Next, the four bite holders 12...
A cutting tool 13 is attached to any three of them, and a dial gauge holder 33 having a dial gauge 32 as shown in FIG. 9 is attached to the remaining one cutting tool holder 12.

(c) Next, attach the device to the inner surface of the body f,
After performing a centering operation and positioning by operating the centering mechanisms 24, 24 and the clamp device 28, the outer cylinder 1 is fixed to the body f with a bolt 34.

(d) Next, slide the device main body 2 in the axial direction according to the dimensions confirmed in advance in step (a) above, and then adjust the diameter of each tool holder 12 to perform cutting of the remaining stellite alloy. Do this. At this time, it is convenient to provide a peephole 35 as shown in FIG. 6 in order to view the vicinity of the cutting tool 13 from the end wall 4a of the gear case 4 so that the work can be visually checked.

(E) After the cutting work is finished, the clamping device 2
8, remove the device from the body f, weld a new stellite alloy i to the valve seat g using another welding device, and then attach the device to the body f again. At this time, the clamp device 2
8, and the centering mechanism 24, 2 is released.
4 remains in the locked state, it is only necessary to relock the clamp device 28, and there is no need to perform centering work again.

(f) After the relocking is completed, the surface of the newly welded stellite alloy i is processed again by rotating the cutting tool 13. At this time, the dial gauge holder 33 is removed and the fourth tool 13 is attached to the tool holder 12. The surface machining work is also performed using the origin confirmed in step (a) above as a reference.

(g) After the above work, the device is removed from the body f again to complete the entire process, and the machined surface of the valve seat g is inspected.

As explained above, according to the present apparatus, not only can many of the processes of cutting the remaining stellite alloy and newly welding the same be automated, but also it is possible to improve the machining accuracy. Note that since the device becomes extremely large depending on the size of the isolation valve c, the gear case 4 may be made separate and connected to the shaft portion of the cylinder 3 or the like from time to time. 10 and 11, the length of the body f in the axial direction is short, and if the main body of the apparatus is only slid relative to the outer cylinder 1, the rear end surface of the body f and the outer cylinder 1
Assuming a case where the flange portions 1a do not touch each other, spacers 36 of various shapes are interposed. In addition, Fig. 12 shows the valve seat g of the isolation valve c, which is machined by the above operation, over time. The same figure shows the remaining stellite alloy i after being cut by the device ((d) above).
This figure shows the state at the end of the new Stellite alloy i welding (step (e) above), and the same figure shows the state at the end of all the steps.

Furthermore, FIG. 13 shows an operation panel 37 for remotely controlling the device, which is connected by wiring from an electrical connection part (not shown) provided in the gear case 4, and is connected to the first, second, and third motors. You will be able to control the driving and stopping of 6, 7, and 8, as well as the number of revolutions. 38 is fixed to the tip of the small cylinder body 22;
This is a television receiver compatible with a television camera 15 that photographs any one of the bytes 13. Carrying out all possible operations remotely in this way greatly increases safety in the unlikely event of radioactivity leakage.

As explained above, the present invention provides a device for cutting the inner surface of a main steam isolation valve in a nuclear power generation device,
The aim is to automate and speed up the cutting work. Since the device main body is inserted into the outer cylinder that is fixed to the inner surface of the body, the device main body can be supported at a location close to the cutting portion. therefore,
This effectively prevents the tip of the device body from shifting. In addition, one of the multiple bits is selected and used, and the selected bit is photographed using a television camera, so the wear status of the bit can always be accurately grasped, and the worn bit can be replaced without delay. Can be done. Therefore, it becomes possible to make the cutting condition good. Therefore, the cutting device of the present invention has high precision and can be applied not only to cutting the valve seat of the body, but also to other cutting operations on the inner surface of the body, cutting operations on other large valves, etc. It has the following characteristics.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a system diagram of a nuclear power generation device, FIG. 2 is a front sectional view of a main steam isolation valve, and FIG. 3 is an enlarged sectional view of the same essential parts.
Fig. 4 is a partially cutaway sectional view of the device of the present invention, Fig. 5 is a longitudinal sectional view of the outer cylinder, Fig. 6 is an end view of the collar of the outer cylinder, Fig. 7 is a sectional view of the clamp device, and Fig. 8. 9 is a front view of the dial gauge holder, FIGS. 10 and 11 are cross-sectional views showing the joint between the collar of the outer cylinder and the rear end surface of the body, and FIG. is an explanatory diagram showing the cutting state of the valve seat, the first
Figure 3 is an overview of the operation panel. DESCRIPTION OF SYMBOLS 1...Outer cylinder, 2...Device main body, 3...Cylinder, 4...Gear case, 5...Screw shaft, 6...First motor, 7
...Second motor, 8...Third motor, 9...Cylinder shaft, 11
...Annular face plate, 12...Bite holder, 13...Bite, 14...Small cylindrical body, 15...TV camera, 16...
Small diameter shaft, 18... Circumferential groove, 19... Notch, 20... U-shaped member, 21... Groove, 22... Arm, 23... Lighting lamp,
24... Centering mechanism, 25, 26... Taper member, 2
8... Clamp device, 32... Dial gauge, 34
...Bolt, 35...Peephole, 36...Spacer, 3
7...Operation panel.

Claims (1)

[Claims] 1. It is attached to the rear end opening side of the main steam isolation valve so that the valve body is brought into contact with and separated from the rear end side of the valve seat provided on the front end side of the body inserted in the valve body, and the inner surface of the body is cut. It is a processing device, and the device has an outer cylinder that is centered and fixed to the inner surface of the body, and a device main body that is inserted into the outer cylinder so as to be slidable at least in the axial direction. The apparatus main body has a small diameter shaft and a cylindrical shaft that are concentric, and has at least a motor that rotates the cylindrical shaft and a motor that moves the small diameter shaft in the axial direction,
Several tool holders each having one tool attached to the tip of the cylindrical shaft can be selectively adjusted in diameter via a diameter adjustment mechanism by axial movement of the small diameter shaft, and A nuclear power generation device characterized in that a work confirmation device having a television camera is provided at the tip of the device body, and the television camera rotates in synchronization with the tool holder to photograph the tool of the selected tool holder. Main steam isolation valve inner surface cutting equipment.