JP2017205839A - Pipe cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently half-splitting cut a pipe, while corresponding to material or thickness thereof.SOLUTION: Pipe 9 to be cut into half-splitting parts are aligned and held by a pipe holding portion 10 of a pipe cutting device 1. An endless strip-shaped band saw 21 of a band saw unit 20 is driven to rotate by a band saw rotation driving portion 25, thereby half-splitting cutting the pipes 9. A feeding mechanism 30 feeds the band saw unit 20 in a length direction MD of the pipe 9. The feeding speed of the band saw unit 20 by the feeding mechanism 30 is variably adjusted by a speed adjusting portion 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pipe cutting device that cuts a pipe in half, and for example, relates to a pipe cutting apparatus that is suitable for cutting the pipe in half in order to perform radiation measurement on the inside of the pipe from a nuclear power plant.

  For example, when disposing of the waste generated in the management area of a nuclear power plant, radiation measurement is performed, and it is confirmed that the contamination is below the standard, and is taken out of the management area. However, since it is difficult to measure the radiation inside the pipe from the outside, the pipe is uniformly packed as a radioactive waste. For this reason, the number of drums increases.

Therefore, if the pipe is cut in half along the pipe axis, the inside can be subjected to radiation measurement, and appropriate disposal can be performed according to the measurement result.
As a means for cutting the tube in half, fusing with a laser or the like can be considered. However, it is conceivable that the internal residue melts together with the pipe at the time of fusing, and then re-solidifies into the half-cut pipe. If this residue contains radioactive material, the radiation will be detected and treated as radioactive waste even if the halved tube itself has no problem.

  In the tube cutting device of Patent Document 1, the tube is held up and down and cut in half by a band saw.

JP 2007-090499 A

In the tube cutting device of Patent Document 1, half cutting proceeds by the band saw being lowered by its own weight. For this reason, as the band saw is worn out, the descending speed becomes slow, and the efficiency is poor.
On the other hand, if the band saw is forcibly lowered at a constant speed, the load on the band saw may become excessive depending on the material, thickness, thickness, number of pipes, etc., which may cause cutting failure or band saw breakage. is there.
It is an object of the present invention to efficiently divide a pipe into half while corresponding to the material, thickness, and the like.

In order to solve the above problems, the present invention is a tube cutting device for cutting a plurality of tubes in half,
A tube holding section for holding the plurality of tubes in a state of being arranged in parallel with each other;
A band saw unit including an endless band-shaped band saw that is driven to rotate across the plurality of tubes;
A feed mechanism for feeding the band saw unit along the length of the tube;
And a speed adjusting unit that variably adjusts the feeding speed of the band saw unit by the feeding mechanism.
According to this apparatus, the band saw unit can be forcibly sent by the feeding mechanism instead of its own weight. Moreover, the feeding speed of the band saw unit can be adjusted to an appropriate value according to the material and thickness of the pipe by the speed adjusting unit. As a result, the tube can be efficiently cut in half.

Preferably, the pipe cutting device is provided with a suitable feed speed information medium representing a preferred feed speed of the band saw unit according to the material and thickness of the pipe.
The feed rate of the band saw unit can be set based on the preferred feed rate information medium.

The preferable feed speed is preferably based on the maximum number of the tubes that can be held by the tube holding unit.
As a result, the number of variables (parameters) that determine the preferred feed rate can be reduced. And it can avoid that cutting load becomes excessive. When the number of cuts is less than the maximum number, cutting can be performed with a margin.

The tube cutting device is configured to detect a load of the band saw unit, an automatic stop unit that stops the driving of the band saw unit and the feed mechanism when detecting an overload when the detected load exceeds a threshold, It is preferable to further include alarm means for notifying overload when overload is detected.
Thereby, work safety can be ensured.

It is preferable that the band saw unit includes a cutting oil nozzle that supplies cutting oil to a portion of the band saw that crosses the plurality of pipes.
Thereby, a pipe | tube can be cut | disconnected more smoothly and abrasion of a band saw can be suppressed.

It is preferable that the band saw unit includes a gas nozzle that blows gas to a portion of the band saw that crosses the plurality of tubes.
The gas can blow off the chips from the band saw. Further, the band saw can be cooled by the gas.

  According to the present invention, the feed rate of the band saw unit can be variably adjusted according to the material and thickness of the tube, and the tube can be cut in half efficiently.

FIG. 1 is a front view illustratively showing a tube cutting device according to an embodiment of the present invention. FIG. 2 is a side view illustratively showing the tube cutting device. FIG. 3 is an explanatory plan view of the tube cutting device taken along line III-III in FIG. FIG. 4 is a perspective view of a part of the tube cutting device. FIG. 5A is a perspective view of one tube receiving plate in the tube cutting device. FIG.5 (b) is sectional drawing of said 1 pipe | tube receiving plate. FIG.5 (c) is sectional drawing of the other pipe receiving plate in the said tube cutting device. FIG. 6 is a table schematically showing an example of the contents of the correspondence table (preferred feed speed information medium).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The cutting target pipe 9 in this embodiment is various pipes discarded in the management area of the nuclear power plant. The straight pipe part of the pipe is cut in half by the pipe cutting device 1. Examples of the material of the tube 9 include stainless steel (SUS) and carbon steel (see FIG. 6).

  As shown in FIGS. 1 to 3, the tube cutting device 1 includes a frame 2, a tube holding unit 10, and a band saw unit 20. The tube holding unit 10 includes a back plate 11, a tube receiving plate 12, and a front pressing portion 14. As shown in FIG. 1, the back plate 11 has a flat plate shape extending in the vertical direction with the width direction directed to the left and right. As shown in FIG. 2, the longitudinal direction of the back plate 11 is inclined to the rear side (right side in FIG. 2) as it goes upward. The upper and lower ends of the back plate 11 are supported by the frame 2.

  A tube receiving plate 12 is detachably attached to the front side portion (left side portion in FIG. 2) of the back plate 11. The tube receiving plate 12 has a plate shape along the back plate 11, and is inclined rearward as it goes upward. As shown in FIG. 5A, a plurality of tube receiving grooves 12 a are formed on the front side surface of the tube receiving plate 12. Each tube receiving groove 12 a extends vertically along the longitudinal direction of the tube receiving plate 12. A plurality of tube receiving grooves 12a are arranged on the left and right. As shown in FIG. 5B, the cross section of the tube receiving groove 12a is semicircular.

  As shown in FIG. 4, the tube 9 is accommodated in each tube receiving concave groove 12 a so as to be directed in the longitudinal direction (feed direction MD) of the tube receiving plate 12. As shown in FIG. 3, the front half (lower side in FIG. 3) of the tube 9 projects forward (downward in FIG. 3) from the tube receiving plate 12. A plurality of tubes 9 are arranged in parallel to each other on the left and right (alignment direction TD orthogonal to the feed direction MD).

  As shown in FIGS. 5B and 5C, a plurality of types of tube receiving plates 12 are prepared according to the size of the tube 9 such as the outer diameter (thickness). The tube receiving plate 12 can be exchanged according to the tube 9 to be cut. These tube receiving plates 12 have substantially the same width. The number of the tube receiving grooves 12a of the tube receiving plate 12 corresponding to the thick tube 9 (the number of the tubes 9 that can be held) is larger than the number of the tube receiving grooves 12a of the tube receiving plate 12 corresponding to the thin tube 9. .

As shown in FIG. 1, the double door type doors 4, 4 are provided on the frame 2 of the tube cutting device 1. As shown by a one-dot chain line in FIG. 2, the rotation axis L ₄ of the door 4 is inclined rearward as it goes upward, and is parallel to the longitudinal direction (feed direction MD) of the back plate 11 and the tube receiving plate 12. It has become. In FIG. 3, the closed door 4 is indicated by a two-dot chain line, and the open door 4 is indicated by a three-dot chain line. Front pressers 14 are provided on the left and right doors 4 respectively. The front presser portion 14 of the left door 4 and the front presser portion 14 of the right door 4 are displaced vertically. When the door 4 is in the closed state, the front pressing portion 14 is opposed to the tube receiving plate 12 in the front-rear direction and presses the tube 9 from the front.

  As shown in FIGS. 1 and 2, the band saw unit 20 includes a band saw 21, a housing 22, a sprocket 23, and a motor 25 (band saw rotation drive unit). The housing 22 extends to the left and right and is inclined so that the lower side portion protrudes forward. An opening 22c is formed at the center of the housing 22 so as to open downward, and the housing 22 has a gate shape. As shown in FIG. 4, the tube receiving plate 12 is passed through the opening 22c.

  As shown in a simplified manner by a two-dot chain line in FIG. 2, the tube cutting device 1 is provided with a support means 3. The band saw unit 20 is supported by the support means 3 so as to be slidable along the feed direction MD. The support means 3 includes, for example, an inclined column 3a extending along the feed direction MD, a slide guide 3b that slidably connects the band saw unit 20 to the inclined column 3a, a suspension cable 3c that supports the band saw unit 20 in a suspended manner, and the like.

As shown in FIG. 1, sprockets 23 and 23 are accommodated on the left and right sides of the housing 22. An axis L ₂₃ (FIG. 2) of the sprocket 23 is inclined forward. A band saw 21 is hung between the left and right sprockets 23, 23. As shown in FIG. 2, a motor 25 is provided on the back of the band saw unit 20. One sprocket 23 is connected to the motor 25 so that torque can be transmitted. The sprocket 23 is rotationally driven by the motor 25, and consequently the band saw 21 is rotated. The rotational speed of the band saw 21 is set to a constant speed.

As shown in FIG. 1, the band saw 21 has a pair of bridging portions 21a and 21b. The bridging portions 21a and 21b are spanned between the left and right sprockets 23 and 23 in parallel with each other. The front side bridging portion 21 a is disposed in the opening 22 c along the front surface of the tube receiving plate 12 and slightly away from the tube receiving plate 12. Torsion mechanisms 24 are provided at positions on both sides of the front side bridging portion 21 a in the band saw unit 20. The torsion mechanism 24 twists the front-side bridging portion 21a and its cutting edge is directed downward. This front side bridging portion 21a crosses the plurality of tubes 9 in the tube holding part 10 in the left and right direction (alignment direction TD).
As shown in FIG. 3, the rear bridging portion 21 b is spanned behind the tube receiving plate 12 (upward in FIG. 3).

  Further, as shown in FIG. 1, a cutting oil nozzle 26 and an air nozzle 27 are provided at positions on both sides of the front bridging portion 21 a in the band saw unit 20. The tip of the cutting oil nozzle 26 is directed to the front side bridging portion 21 a of the band saw 21. A cutting oil supply source (not shown) is connected to the base end portion of the cutting oil nozzle 26. Preferably, the cutting oil nozzle 26 is provided on the upstream side (left side in FIG. 1) in the rotation direction (left to right direction in FIG. 1) of the front side bridging portion 21a.

The tip of the air nozzle 27 (gas nozzle) is directed to the front side bridging portion 21 a of the band saw 21. A compressed air supply source (not shown) is connected to the base end portion of the air nozzle 27.
The air nozzle 27 is provided on the downstream side (right side in FIG. 1) in the rotation direction (left to right direction in FIG. 1) of the front bridge portion 21a, but may be provided on the upstream side, It may be provided on both downstream sides.

As shown in FIG. 2, the feed mechanism 30 includes a feed screw 31, a feed nut 32, and a motor 35. The feed screw 31 is disposed obliquely behind the back plate 11 and extends parallel to the longitudinal direction of the back plate 11 (feed direction MD). Both ends of the feed screw 31 are rotatably supported by the frame 2. A feed nut 32 is screwed to the feed screw 31. The housing 22 of the band saw unit 20 is connected to the feed nut 32.
A motor 35 (feed driving unit) is connected to the feed screw 31. When the feed screw 31 is rotated around its own axis by the motor 35, the feed nut 32 and the band saw unit 20 are moved up and down (lifted) along the feed direction MD.

  Furthermore, the tube cutting device 1 includes a controller 50 (speed adjusting unit). The controller 50 includes a processing unit (CPU), a memory, an input / output circuit, a motor drive circuit, and the like. An operation panel 51 is connected to the controller 50. The operation panel 51 can be used to set and input the feeding speed of the band saw unit 20. The setting input means may be a push button, a dial, a touch panel, or a keyboard. The controller 50 adjusts the output of the motor 35 according to the speed set by the operation panel 51, and consequently adjusts the feed speed (downward speed) of the band saw unit 20 by the feed mechanism 30.

  As shown in FIG. 2, the pipe cutting device 1 is further provided with a correspondence table 52 (preferred feed speed information medium). As shown in FIG. 6, the correspondence table 52 represents a suitable feed speed according to the material and thickness (outer diameter) of the tube 9. The nominal diameter is used as the thickness. Further, as described above, the tube receiving plate 12 to be used is determined according to the thickness of the tube 9, and therefore the number of the tube receiving concave grooves 12a is determined. As a result, the maximum number of tubes 9 that can be held by the tube holding unit 10 is determined. The preferred feed speed is preferably set such that the number of tubes 9 held is the maximum number. This can reduce the number of parameters that determine the preferred feed rate. In general, the thickness of the tube 9 is determined according to the nominal diameter. Therefore, if the nominal diameter is used as a parameter, it is not necessary to add thickness to the parameter. Therefore, the number of parameters can be further reduced, and the correspondence table 52 can be further simplified.

  The correspondence table 52 may be written on paper or the like and arranged near the operation panel 51, or may be displayed on an attached monitor (not shown) of the controller 50 or the like.

Information described in the correspondence table 52 (material, nominal diameter, and preferred feed speed of the tube 9) is acquired by conducting a test before the tube cutting apparatus 1 is officially or fully operated. That is, the sample of the tube 9 is cut using the tube cutting device 1 in advance by changing the feeding speed of the band saw unit 20. A feed speed at which the load on the band saw 21 does not become excessive and can be cut in a shorter time is set as a preferred feed speed.
In general, the thicker the tube 9, the smaller the maximum number of tubes held by the tube holder 10 and the smaller the load applied to the band saw 21, so that the preferred feed rate can be set faster.

  As shown in FIG. 1, a load limiter 60 and an alarm means 65 are mounted on the tube cutting device 1. The load limiter 60 includes a load detection circuit 61 (load detection means) and a stop circuit 62 (automatic stop means). The alarm means 65 is constituted by a warning light, a speaker, a monitor and the like.

The tube cutting device 1 is used as follows.
A suitable feed speed corresponding to the material and nominal diameter (outer diameter) of the tube 9 to be cut is determined from the correspondence table 52. This preferred feed rate is set and input to the controller 50 by the operation panel 51.
The tube 9 is set in the tube receiving groove 12a. Subsequently, the door 4 is closed. As a result, the tube 9 can be held by being sandwiched between the tube receiving plate 12 and the front pressing portion 14.
Next, while the band saw 21 is rotated at a constant speed by the motor 25 of the band saw unit 20, the feed mechanism 30 feeds the band saw unit 20 and thus the band saw 21 downward from the upper end along the feed direction MD. Thereby, the tube 9 can be cut in half in the length direction. A plurality of pipes 9 can be cut in half at a time. At this time, the output of the motor 35 is adjusted by the controller 50, and as a result, the feed speed (downward speed) of the band saw unit 20 is adjusted to the set speed of the operation panel 51. Thereby, the pipe | tube 9 can be efficiently cut in half at a suitable speed corresponding to its material and thickness.
By setting the number of tubes 9 corresponding to the preferred feed rate to the maximum number of tubes 9 held by the tube holder 10, it is possible to avoid an excessive cutting load. When the number of holdings is less than the maximum number, it can be cut with a margin.
At the same time, the cutting oil is supplied from the cutting oil nozzle 26 to the front side bridging portion 21a of the band saw 21 and the like. Thereby, the cutting resistance of the tube 9 can be reduced and the temperature rise of the band saw 21 can be suppressed, so that the wear of the band saw 21 can be suppressed. Further, air (gas) is blown from the air nozzle 27 to the front side bridge portion 21 a of the band saw 21 and the like. With this air, the chips can be blown off from the band saw 21 and the band saw 21 can be cooled.
In addition, it is preferable to provide a tray (not shown) at the bottom of the tube receiving plate 12 so that the chips are accumulated on the tray.
During driving of the band saw 21, the load applied to the band saw 21 is detected by the load detection circuit 61 of the load limiter 60. As the wear of the band saw 21 progresses, the load applied to the motor 25 and the like of the band saw unit 20 increases. When the load detection circuit 61 detects that the load exceeds the threshold (when overload is detected), the stop circuit 62 stops driving the tube cutting device 1. Thereby, work safety can be ensured.
Furthermore, when overload is detected, the alarm means 65 is activated to notify the overload. Accordingly, appropriate measures such as exchanging the band saw 21 can be performed.

By halving the tube 9, the radiation dose in the tube 9 can be measured. Based on this measurement result, the tube 9 can be carried out of the management area as a reused item.
Preferably, a plurality of pipe cutting devices 1 are prepared in the management area of the nuclear power plant. The target contamination level is determined for each tube cutting device 1. About the pipe | tube 9 estimated that there is no contamination or a low pollution degree, the low contamination level pipe | tube cutting device 1 carries out a half cut. The pipe 9 that is predicted to have a high degree of contamination is cut in half by the high contamination level pipe cutting device 1. As a result, it is possible to prevent the low contamination level tube cutting device 1 from being contaminated by the highly contaminated tube 9. Eventually, when the new low-contamination level pipe cutting device 1 halves a new low-contamination pipe 9, the new pipe 9 can be prevented from being contaminated.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the length direction of the tube 9 and thus the feed direction MD of the band saw unit 20 is not limited to an oblique direction, and may be vertical or horizontal.
The information of the correspondence table 52 may be stored as a database in the memory of the controller 50. The memory may function as a suitable feed speed information unit. When the material or nominal diameter of the tube 9 is input through the operation panel 51, the controller 50 may retrieve a suitable feed speed from the database and adjust the output of the motor 35 based on this. The controller 50 may display the retrieved preferable feed speed on the monitor.
The pipe cutting device 1 is not limited to the pipe 9 of the nuclear power generation facility, and can be applied to cut various pipes in half.

  The present invention, for example, inspects the internal contamination status of piping materials for reuse of piping materials transported from the management area of a nuclear power plant, and effectively uses limited resources based on the clearance system in the Reactor Regulation Act. Applicable to.

MD feed direction (pipe length direction)
DESCRIPTION OF SYMBOLS 1 Pipe cutting device 9 Pipe 10 Pipe holding part 20 Band saw unit 21 Band saw 25 Motor (band saw rotation drive part)
26 Cutting oil nozzle 27 Air nozzle (gas nozzle)
30 Feed mechanism 50 Controller (Speed adjustment unit)
52 Correspondence table (preferred feed speed information medium)
61 Load detection circuit (load detection means)
62 Stop circuit (automatic stop means)
65 Alarm means

Claims (6)

A pipe cutting device for cutting a plurality of pipes in half,
A tube holding section for holding the plurality of tubes in a state of being arranged in parallel with each other;
A band saw unit including an endless band-shaped band saw that is driven to rotate across the plurality of tubes;
A feed mechanism for feeding the band saw unit along the length of the tube;
A tube cutting apparatus comprising: a speed adjusting unit that variably adjusts a feeding speed of the band saw unit by the feeding mechanism.   The pipe cutting device according to claim 1, further comprising a suitable feed speed information medium representing a preferred feed speed of the band saw unit according to a material and a thickness of the pipe.   The tube cutting device according to claim 2, wherein the suitable feed speed is based on a maximum number of the tubes that can be held by the tube holding unit. Load detecting means for detecting the load of the band saw unit;
Automatic detection means for stopping the driving of the band saw unit and the feed mechanism upon detection of an overload when the detected load exceeds a threshold;
The pipe cutting device according to any one of claims 1 to 3, further comprising alarm means for notifying overload when the overload is detected.   The pipe cutting device according to any one of claims 1 to 4, wherein the band saw unit includes a cutting oil nozzle that supplies cutting oil to a portion of the band saw that crosses the plurality of pipes.   The tube cutting device according to any one of claims 1 to 5, wherein the band saw unit includes a gas nozzle that blows gas to a portion of the band saw that crosses the plurality of tubes.

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