JP2004216525A - Pipe inner face polishing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly remove oxide deposits in a pipe in which the oxide deposits including contaminants exist on the inner face, with remote control under an environment such as in a reactor of an atomic power plant while reducing exposure to radiation and effectively preventing the dispersion of the contaminants. <P>SOLUTION: This pipe inner face polishing device comprises a rotation driving motor 7, a rotational shaft 8 connected to the motor and inserted at its front end to the pipe to be polished when rotated around an axial center, a machining head 9 provided at the front end of the rotational shaft for polishing, and a feed mechanism 10 for moving the motor 7, the rotational shaft 8 and the machining head 9 along the axial direction of the pipe 2. The machining head 9 has an expansion polishing tool 27 whose diameter is shrunk to be smaller than the inner diameter of the pipe during non-rotation and expanded during rotation by centrifugal force so that the outer peripheral face comes into contact with the inner face of the pipe 2 for polishing. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pipe inner surface polishing apparatus suitable for removing an oxide film or the like formed on the inner surface of a pipe provided in, for example, a nuclear power plant.
[0002]
[Prior art]
Conventionally, as a pipe inner surface polishing apparatus, a cleaning liquid in which a granular material is mixed is passed through a pipe, and the granular material is polished by colliding with a deposit on the inner surface of the pipe (see Patent Document 1). A belt sander is inserted and moved back and forth (see Patent Literature 2), and a magnetic grindstone is slid on the inner surface of a pipe by an electromagnetic force and polished (see Patent Literature 3).
[0003]
However, in these conventional techniques, the treatment of the cleaning liquid mixed with the granular material is troublesome, and it is difficult to uniformly polish the entire inner surface of the pipe by using a belt sander or a grindstone. However, it is not necessarily suitable for polishing the inner surface of a pipe provided in a nuclear power plant or the like for which it is strongly desired.
[0004]
Conventionally, as another means, a polishing tool such as a flap wheel is attached to a general-purpose tool such as a grinder, and an operator may perform polishing manually. However, in that case, it is possible to polish only near the opening, and it is difficult to polish uniformly because a human uses a tool.
[0005]
In addition, contaminants may be present in the pipes provided in nuclear power plants and the like. Recruitment is difficult. In particular, when the contaminants on the inner surface of the pipe may be scattered as fine dust, the danger increases, and manual work near the pipe is more difficult.
[0006]
In addition, it is conceivable to attach a general-purpose tool to the moving mechanism for moving the pipe in the axial direction, insert the tool into the pipe, and grind the pipe inner surface. However, when using a general-purpose polishing tool having an outer diameter substantially equal to the inner diameter of the pipe, a general-purpose polishing jig having an inner diameter sufficiently smaller than the inner diameter of the pipe cannot be easily rotated because the resistance is large. It is also conceivable to apply. However, in this case, although the generated resistance is small, the inner surface of the pipe cannot be uniformly polished due to a partial contact or the like.
[0007]
[Patent Document 1]
JP-A-5-279
[Patent Document 2]
JP-A-8-112747 [0009]
[Patent Document 3]
Japanese Patent Application Laid-Open No. 9-131653
[Problems to be solved by the invention]
Each of the conventional techniques described above has problems in terms of simple processing, uniform polishing, and the like. In addition, the polishing of the inner surface of a pipe of a nuclear power plant or the like has various problems from the viewpoints of the expansion of contamination and the possibility of exposure.
[0011]
The present invention has been made in view of such circumstances, and it is easy to move the pipe in the axial direction, and it is possible to polish the inner surface of the pipe uniformly, and it is also effective in preventing the spread of contamination and reducing exposure. An object of the present invention is to provide a pipe inner surface polishing apparatus.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, in the invention according to claim 1, a motor for rotational driving, a rotating shaft connected to the motor, the tip of which is inserted into a pipe to be polished and rotated about the axis, A processing head for polishing provided on the distal end side of the rotating shaft, and a feed mechanism for moving the motor, the rotating shaft and the processing head along the axial direction of the tube, the processing head being non-rotating It is characterized by having an expansion-contraction type polishing tool for reducing the diameter to become smaller than the inner diameter of the tube, and expanding the diameter by centrifugal force during rotation so that the inner surface of the tube comes into contact with the outer surface to perform polishing. A pipe inner surface polishing apparatus is provided.
[0013]
In the invention according to claim 2, the polishing tool has a cloth blade portion formed radially on the same axis as the rotation shaft and bulging to the outer diameter side by centrifugal force. A pipe inner surface polishing apparatus is provided.
[0014]
In the invention according to claim 3, the tube inner surface according to claim 1, further comprising a remote control device for remotely controlling polishing for the rotation speed of the motor, the feed amount of the rotary shaft by the feed mechanism, a stop position, and the like. A polishing apparatus is provided.
[0015]
In the invention according to claim 4, the inner surface polishing pipe according to claim 1, further comprising: a sealing mechanism for sealing an end portion of the pipe on the rotating shaft insertion side; and a dust collector for sucking and collecting polishing dust from inside the pipe to the outside of the pipe. Provide equipment.
[0016]
In the invention according to claim 5, the processing head has a non-expansion type polishing tool at a position eccentric to the rotation axis, instead of the expansion / contraction type polishing tool. Provide equipment.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a pipe inner surface polishing apparatus according to the present invention will be described with reference to the drawings.
[0018]
FIG. 1 is an overall configuration diagram of the pipe inner surface polishing apparatus. FIG. 2 is an enlarged partial cross-sectional view showing a main part of the apparatus, and FIG. 3 is an enlarged configuration view showing a polishing tool.
[0019]
In the present embodiment, as shown in FIG. 1, the inner surface of one of the plurality of parallel pipes 2, 2 a, 2 b vertically fixedly arranged above the work floor 1 of the nuclear power plant is moved downward. An example of the pipe inner surface polishing apparatus 3 for polishing from below will be described. The lower end of each of the tubes 2, 2a, 2b shown in the drawing is in a state of being opened by detaching a connecting tube thereunder, respectively, and a pipe inner surface polishing device 3 is provided below these tubes 2, 2a, 2b. Is installed.
[0020]
The pipe inner surface polishing apparatus 3 is roughly divided into a main body 4 as a polishing operation section connected to the pipes 2, 2a, 2b, and a remote control device (control panel) 5 for controlling the operation of the main body 4. And a dust collector 6 for sucking and collecting polishing dust generated by polishing work in the pipe 2 to be polished from inside the pipe to outside the pipe.
[0021]
The main body 4 includes a rotation driving motor 7, a rotation shaft 8 connected to the motor 7, the rotation end of which is inserted into the tube 2 to be polished, and which rotates around the axis. And a feed mechanism 10 for moving the motor 7, the rotating shaft 8 and the processing head 9 along the axial direction (vertical direction) a of the tube 2.
[0022]
The configuration of the main body 4 is shown in detail in FIG. As shown in FIG. 2, the main body 4 has a horizontal mounting plate 12 which is detachably mounted on the lower surfaces of the flanges 11 and 11a of the pipes 2 and 2a and the like. , 11a with mounting screws 13. The mounting plate 12 is provided with a vertically long communication pipe portion 14 communicating with the lower end portion of the pipe 2 to be polished. Through the communication pipe section 14, the above-described rotating shaft 8 and the processing head 9 and the like are placed inside the pipe 2. To be inserted from below. A feed mechanism holding frame 15 that holds the feed mechanism 10 is provided on the lower surface of the mounting plate 12.
[0023]
The feed mechanism 10 is provided at a feed mechanism holding frame 15 with a feed drive unit 16 such as a motor and a speed reducer that is variable in rotational speed and rotational direction, and is disposed vertically below the feed drive unit 16 for rotation. The ball screw 17 and a nut 18 for movement that engages with the ball screw 17 are provided.
[0024]
The moving nut 18 is integrally provided with a motor connector 19, and the motor connector 19 supports the above-described motor 7 for rotational drive. The motor 7 has an output shaft (not shown) pointing vertically upward, and the lower end of the above-described vertical rotation shaft 8 is connected to this output shaft. The motor 7 has a variable rotation speed and rotation direction.
[0025]
The control panel 5 shown in FIG. 1 is electrically connected to a motor 7 for driving the rotating shaft 8 and a feed driving unit 16 of the feed mechanism 10. Polishing control such as the feed amount of the shaft 8 and the stop position is performed remotely. That is, the control panel 5 can set a polishing speed (rotation speed), a stop time at one location (polishing time), an axial feed amount, a traveling direction, and the like, and is provided with a start switch and the like. In addition, the control panel 5 displays a polishing speed (rotation speed), an axial position, an axial feed amount, and the like. Thus, remote automatic operation is possible by setting the polishing speed (rotation speed), the polishing time at one location, and the feed speed in the axial direction in advance.
[0026]
Around the rotating shaft 8, a vertical connecting pipe 20 whose lower end is fixed to an outer shell of the motor 7 or the like is arranged. The rotating shaft 8 and the connecting pipe 20 extend to substantially the same height position, These upper ends can be inserted from below into the pipe 2 to be polished via the communication pipe section 14. A seal mechanism 21 is provided at the lower end of the communication pipe portion 14, that is, at the end on the rotary shaft insertion side of the pipe 2, whereby the inside of the pipe 2 is hermetically sealed from the outside.
[0027]
A hole 22 for discharging the swarf is formed in a portion of the pipe wall of the communication pipe portion 14 on the upper end side of the seal mechanism 21, and a swarf discharging pipe 23 is connected to the hole 22. Further, the polishing waste discharge pipe 23 is connected to the dust collector 6 via a flexible hose 24. The polishing waste discharge pipe 23 is stably supported and fixed by a connecting member 25 attached to a lower end of the communication pipe portion 14.
[0028]
A processing head 9 is provided at an upper end of the rotating shaft 8. FIG. 3 shows the processing head 9 in detail. As shown in FIG. 3, the processing head 9 is configured to include a tool holding unit 26 that rotates integrally with the rotating shaft 8 and a polishing tool 27 that is detachably held by the tool holding unit 26.
[0029]
The tool holding part 26 is concentrically connected to a bearing part 28 such as a ball bearing integrally provided at an upper end of the connecting pipe 20 surrounding the rotating shaft 8 via a pin 29 at an upper end of the rotating shaft 8, and The rotary holder 30 is supported by the bearing portion 28 and rotates around a vertical axis. The rotary holder 30 includes an attachment / detachment tool 31 for attaching / detaching a polishing tool.
[0030]
The attachment / detachment tool 31 has, for example, an opening at an upper end side, and holds a vertical shaft inserted from above, detachably and integrally rotatable.
[0031]
The polishing tool 27 is reduced in diameter during non-rotation to have a diameter smaller than the inner diameter of the tube 2, and is expanded by centrifugal force during rotation, so that the outer peripheral surface of the polishing tool 27 comes into contact with the inner surface of the tube 2 to perform polishing. It is configured.
[0032]
That is, the polishing tool 27 is detachably inserted from above into the attachment / detachment tool 31 and held, and is rotatable coaxially with the rotation shaft 8, and provided on the shaft body 32 and on the same axis as the rotation shaft 8. And a blade 33 made of cloth which is formed radially. The blade 33 is provided with an abrasive.
[0033]
Then, when the blade portion 33 rotates around the vertical axis (in the direction of the arrow b in FIG. 3) together with the shaft body 32, the blade portion 33 expands toward the outer diameter side due to centrifugal force and expands in diameter. (See arrow c in FIG. 3 and a virtual line).
[0034]
When the polishing operation is performed in the above-described configuration, first, as a preparatory operation, as shown in FIGS. 1 and 2, the polishing operation is performed on the flanges 11, 11 a of the pipes 2, 2 a having open lower ends. The plate 12 is mounted with mounting screws 13. At the time of this mounting, the motor 7 and the rotating shaft 8 and the like are in a state of being arranged at the lowermost position in the elevating position. In this preparation stage, since the processing head 9 has not yet been inserted into the pipe 2, the processing head 9 is disposed below the state shown in FIG. 2 and is housed in the communication pipe portion 14.
[0035]
In this state, the polishing operation is started by driving the motor 7 and the feed mechanism 10 by operating the switches on the control panel 5 shown in FIG.
[0036]
When the polishing operation is started, the ball screw 17 of the feed mechanism 10 rotates by a predetermined amount, and raises the rotating shaft 8 vertically upward along the ball screw 17. As a result, the processing head 9 rises and is inserted into the pipe 2 to be in the state shown in FIG.
[0037]
Then, when the processing head 9 is rotated via the rotation shaft 8 by the drive of the motor 7, the polishing tool 27 of the processing head 9 is expanded to be larger than the inner diameter of the tube 2 by centrifugal force. The diameter-increased polishing tool 27 rotates while being pressed against the inner surface of the tube 2, whereby the inner surface of the tube 2 is polished. That is, the oxide film containing the contaminants on the inner surface of the pipe 2 is removed by the polishing tool 27 and becomes dust. Although the diameter of a normal polishing tool does not increase so much even when it is rotated, the polishing tool 27 of the present embodiment has a long blade portion 33 and is sufficiently spread by centrifugal force generated during rotation.
[0038]
As for the progress of the inner surface polishing, polishing control such as the number of rotations of the motor 7, the feed amount of the rotating shaft 8 by the feed mechanism 10, the stop position, and the like is remotely performed by the control panel 5. That is, in the control panel 5, a polishing speed (rotation speed), a stop time at one location (polishing time), an axial feed amount, and a traveling direction can be set, and further, a polishing speed (rotation speed), an axial position. , The feed amount in the axial direction is displayed. As a result, remote work is reliably performed.
[0039]
Dust containing contaminants generated by the polishing is sent from the hole 22 of the communication pipe portion 14 to the dust collector 6 via the polishing waste discharge pipe 23 and the hose 24, and the contaminants are separated and extracted by a filter inside the dust collector. . In addition, since the seal mechanism 21 is provided at the lower end of the communication pipe section 14, outside air is not sucked into the pipe, and contaminants do not leak to the outside.
[0040]
As described above, dust containing contaminants generated during polishing is sucked into the dust collector 6 together with the air, and the sucked dust is separated by the filter, thereby preventing the spread of contamination.
[0041]
In addition, by setting the polishing speed, the polishing time at one location, and the feed speed in the axial direction in advance, remote operation is possible, and as a result, exposure of workers can be reduced.
[0042]
In the present invention, it is also possible to adopt a configuration in which a non-diameter-type polishing tool is provided at a position eccentric to the rotating shaft 8 instead of the expansion / contraction-type polishing tool 27. With such a configuration, since the axis of the polishing tool is eccentric to the rotation axis of the processing head 9, a general-purpose polishing tool can be used instead of the polishing tool that spreads by rotation. Therefore, by using a general-purpose polishing tool, it is possible to perform the same operation as in the above-described embodiment.
[0043]
【The invention's effect】
As described above, according to the present invention, the oxide film of a pipe having an oxide film containing contaminants on its inner surface is used in an environment where a person cannot stay near the pipe for a long time, for example, in a nuclear reactor of a nuclear power plant. Even in such an environment, the oxide film can be uniformly removed by remote control, and thus the exposure dose can be reduced and the diffusion of contaminants can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a pipe inner surface polishing apparatus showing an embodiment of the present invention.
FIG. 2 is an enlarged view showing a main part of FIG. 1 as a partial cross section.
FIG. 3 is a configuration diagram showing a polishing tool according to an embodiment of the present invention in a further enlarged manner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Work floor 2, 2a, 2b Pipe 3 Pipe inner surface polishing device 4 Main body 5 Remote control device (control panel)
6 Dust collector 7 Motor 8 Rotating shaft 9 Processing head 10 Feed mechanism 11, 11a Flange part 12 Mounting plate 13 Mounting screw 14 Communication pipe part 15 Feed mechanism holding frame 16 Feed drive 17 Ball screw 18 Moving nut 19 Motor coupler 20 Connection Pipe 21 Sealing mechanism 22 Hole 23 Polishing waste discharge pipe 24 Hose 25 Connector 26 Tool holder 27 Polishing tool 28 Bearing 29 Pin 30 Rotation holder 31 Removable tool 32 Shaft 33 Blade part

Claims (5)

A rotary drive motor, a rotary shaft connected to the motor, the tip of which is inserted into a pipe to be polished and rotated around the axis, and a polishing processing head provided on the tip of the rotary shaft. A feed mechanism for moving the motor, the rotating shaft and the processing head along the axial direction of the tube, wherein the processing head is reduced in diameter during non-rotation to have a diameter smaller than the inner diameter of the tube, and during rotation. A tube inner surface polishing apparatus, comprising: an expansion / contraction type polishing tool for performing polishing by expanding the diameter by centrifugal force so that the outer surface of the tube comes into contact with the inner surface of the tube. The pipe inner surface polishing apparatus according to claim 1, wherein the polishing tool has cloth blades formed radially on the same axis as the rotating shaft and bulging to the outer diameter side by centrifugal force. The tube inner surface polishing apparatus according to claim 1, further comprising a remote control device for remotely controlling polishing for the rotation speed of the motor, the feed amount of the rotary shaft by the feed mechanism, a stop position, and the like. 2. The pipe inner surface polishing apparatus according to claim 1, further comprising: a sealing mechanism for sealing an end of the pipe on a rotating shaft insertion side; and a dust collector for sucking and collecting polishing dust from inside the pipe to the outside of the pipe. 3. The pipe inner surface polishing apparatus according to claim 1, wherein the processing head has a non-expansion type polishing tool at a position eccentric to the rotation axis, instead of the expansion / contraction type polishing tool.

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