Cutting device, cutting method, decontamination line

Abstract

To cut a bent tube into two along a tube axis.SOLUTION: A cutting device 10 for cutting a bent tube 1 into two along a tube axis V comprises: an endless band saw blade; a first drive 37 that rotationally drives the band saw blade in a vertical direction; a pair of rollers 51 and 52 positioned on both sides sandwiching the band saw blade 35 and brought at the outer peripheral surfaces into contact with the outer and inner peripheral surfaces of the bent tube 1 at the cutting position of the band saw blade 35; and a second drive 71 that rotary-drives at least one of the pair of the rollers 51 and 52.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a technique for cutting a bent pipe. [Background technology]

[0002] When replacing or disposing of high-pressure feed water heaters used in BWR-type nuclear power plants, etc., it is necessary to open the thin tubes in the longitudinal direction for decontamination. Patent Document 1 discloses a cutting device for cutting straight tubes whose tube axes are straight. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4035083 Summary of the Invention [Problem to be solved by the invention]

[0004] Pipes may have not only straight sections, but also curved sections. Currently, there is no practical device for cutting bent pipes with curved pipe axes. This makes it difficult to decontaminate the bent pipes, which can cause problems during disposal work. Similar issues exist not only when disposing of contaminated pipes, but also when reusing other pipes. Against this background, there has been a demand for the development of a device for cutting bent pipes with curved pipe axes. [Means for solving the problem]

[0005] A cutting device that cuts a bent tube into two pieces along the tube axis comprises an endless band saw blade, a first drive unit that drives the band saw blade in an up and down orbit, a pair of rollers located on either side of the band saw blade and contact the outer and inner surfaces of the bent tube, respectively, at the cutting position by the band saw blade, and a second drive unit that drives and rotates at least one of the pair of rollers, and the bent tube is positioned and fed relative to the band saw blade using the pair of rollers, and is cut into two pieces by the band saw blade.

[0006] With this configuration, a curved pipe can be cut into two along its axis regardless of the bending radius, making it possible to decontaminate not only the straight pipe but also the bent pipe, for example, and thus to dispose of the contaminated pipe efficiently.

[0007] As one embodiment of the present invention, one of the pair of rollers may be a drive roller and the other a driven roller. The drive roller may have a coating layer on its outer circumferential surface that has higher friction than the driven roller. The driven roller may be a movable roller whose roller axis position is adjustable. With this configuration, it is possible to maintain contact between the drive roller and the bent tube during transport, enabling smooth feeding and cutting of the bent tube.

[0008] In one embodiment of the present invention, the rollers having the function of feeding the bent pipe may be a pair of rollers only, and no other rollers for feeding may be used. By adopting such a configuration, the bent pipe can be fed smoothly. Effect of the Invention

[0009] According to the present invention, a bent pipe with a curved axis can be cut along the axis regardless of the bending radius. By cutting along the axis of the pipe that is aligned with the bending radius, it can be made into a straight flat plate in a post-process, which not only enables efficient decontamination but also reduces the storage space required after decontamination. [Brief description of the drawings]

[0010] [Figure 1] U-tube decontamination process [Diagram 2] Plan of the decontamination line [Diagram 3] Perspective view of U-tube cutting device [Figure 4] Oblique view of the main part of the U-shaped tube cutting device [Diagram 5] Schematic diagram of the cutting device body [Figure 6] Close-up of the positioning device [Figure 7] Close-up of the positioning device [Figure 8] Diagram showing the cutting process of U-tube 1 [Figure 9] Diagram showing the cutting process of U-tube 1 [Figure 10] Front view of rolling mill [Figure 11] Plan view of the rolling mill [Figure 12] A perspective view of a main part of a rolling mill [Figure 13] FIG. 1 is a perspective view showing the internal structure of a rolling device; [Figure 14] FIG. 1 is a perspective view showing the internal structure of a rolling device; [Figure 15] Diagram showing the arrangement of rolling rollers [Figure 16] The rolling device is seen from the direction A in Figure 12. [Figure 17] Leveller front view [Figure 18] Leveller floor plan [Figure 19] Figure 18 viewed from direction A [Figure 20] FIG. 1 is a perspective view showing the internal structure of a leveller [Figure 21] FIG. 1 is a perspective view showing the internal structure of a leveller [Figure 22] Diagram showing the arrangement of correction rollers [Figure 23] Side view of the decontamination equipment [Figure 24] Plan view of the decontamination equipment [Diagram 25] Perspective view of decontamination equipment [Figure 26] Oblique view of the main parts of the decontamination equipment [Figure 27] Perspective view of the conveying section [Figure 28] Perspective view of the decontamination device body [Figure 29] Vertical section of Fig. 28 [Diagram 30] Conceptual diagram of air blast equipment [Diagram 31] Perspective view of the blast head and connecting part [Diagram 32] FIG. 3 is an exploded perspective view showing the structure of the outer wall portion. [Diagram 33] 31 is an exploded perspective view of FIG. [Diagram 34] Vertical section of Fig. 31 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Embodiment> An embodiment of the present invention will be described with reference to FIGS. When carrying out dismantling work for a nuclear power plant, it is necessary to remove and dismantle metal pipes (hereinafter, thin pipes) from high-pressure feed water heaters and condensers. The thin pipes are removed by dividing them into a straight pipe section and a U-shaped pipe 1. In this embodiment, a "U-shaped pipe cutting device 10" is used in a decontamination line L for the U-shaped pipe 1 removed from the high-pressure feed water heater or condenser. The U-shaped pipe 1 is not limited to only a curved pipe section having an arc shape, but may also include a straight pipe section.

[0012] 1. Decontamination procedure for U-tube 1 FIG. 1 is a process diagram of the decontamination work of a U-tube 1. The decontamination work will be carried out through the following steps: (a) The process of cutting out U-tubes 1 (the U-shaped part of the thin tube) from a heat exchanger or a condenser (b) cutting the cut U-shaped tube 1 into two pieces along the tube axis V (c) A process of rolling the two cut U-tubes 1A. (d) A process of straightening the curvature of the U-shaped tube 1B after rolling along the tube axis V (e) Process of decontaminating U-tube 1C after straightening

[0013] By steps (a) to (e), the removed U-shaped tube 1 can be decontaminated and disposed of as waste. Note that reference symbol 1A denotes the U-shaped tube after cutting into two pieces, reference symbol 1B denotes the U-shaped tube after rolling, reference symbol 1C denotes the U-shaped tube after straightening, and reference symbol 1D denotes the U-shaped tube after decontamination.

[0014] In this embodiment, as shown in Fig. 2, the decontamination line L is composed of four devices: a U-shaped tube cutting device 10, a rolling device 100, a leveller 200, and a decontamination device 300, and the steps (b) to (e) can be carried out in an assembly line. The symbol U indicates the work space of the workers.

[0015] Below, we will sequentially explain the U-shaped tube cutting device 10, the rolling device 100, the leveller 200, and the decontamination device 300. In addition, with regard to directions, the conveying direction of the U-shaped tube 1 is defined as the X direction, the direction perpendicular to the X direction is defined as the Y direction, and the up-down direction is defined as the Z direction.

[0016] 2. Description of U-tube cutting device 10 FIG. 3 is a perspective view of the U-shaped pipe cutting device 10, FIG. 4 is a perspective view of the main part of the U-shaped pipe cutting device 10, and FIG. 5 is a schematic diagram of the cutting device main body.

[0017] 3 and 4, the U-shaped tube cutting device 10 includes a cutting device main body 20 and a support stand 23 that supports the U-shaped tube 1. In this embodiment, the U-shaped tube 1 is supported at two points by two support stands 23A and 23B.

[0018] The cutting device main body 20 is a vertical band saw cutting machine, and as shown in Figure 5, is equipped with a work table 25, a pair of upper and lower pulleys 31, 33, an endless band saw blade 35 stretched between the two pulleys 31, 33, a drive motor 37, and gears G1, G2.

[0019] A through hole 26 through which a band saw blade 35 passes is formed in approximately the center of the work table 25. When the drive motor 37 is driven, power is transmitted to the pulley 31 via gears G1 and G2, and the two pulleys 31 and 33 are rotated. As a result, the band saw blade 35 moves in an up-down orbit while passing vertically through the through hole 26 of the work table 25. The two pulleys 31 and 33 and the drive motor 37 correspond to a "first drive device" of the present invention.

[0020] As shown in FIG. 4, the cutting device body 20 further includes a metal base 40 fixed to the work table 25, a positioning device 50, and a roller driving device .

[0021] The positioning device 50 is a device that positions the U-shaped tube 1 relative to the band saw blade 35, and as shown in Figures 5 to 7, consists of a first roller 51, a second roller 52, an adjustment device 55, a metal guide plate 60, and a metal lock plate 65.

[0022] 5 and 6, the first roller 51 and the second roller 52 are located on both sides (both sides in the Y direction) of the band saw blade 35. The two rollers 51, 52 are horizontal rollers with rotation axes C1, C2 facing up and down. The first roller 51 is a fixed roller with the position of the rotation axis C1 fixed, and the second roller 52 is a movable roller with the position of the rotation axis C2 adjustable in the Y direction.

[0023] The guide plate 60 is located above the base 40 and is fixed to the base 40 via the boss 43 and the fixed wall 57A. The guide plate 60 has a circular relief groove 66 corresponding to the position through which the band saw blade 35 passes.

[0024] The base 40 and the guide plate 60 are formed with rectangular guide holes 41, 61, respectively, each of which is elongated in the Y direction.

[0025] The adjustment device 55 is a device that adjusts the position of the second roller 52 in the Y direction. In this embodiment, the adjustment device 55 is made up of a roller guide 56 and a screw mechanism 57, as shown in FIG.

[0026] The roller guide 56 is U-shaped and includes an upper plate 56A, a lower plate 56B, and a connecting plate 56C. The connecting plate 56C connects the upper and lower plates 56A and 56B. The upper and lower plates 56A and 56B rotatably hold the roller shaft C2 of the second roller 52.

[0027] The upper plate 56A slidably fits into a guide hole 61 of the guide plate 60, and the lower plate 56B slidably fits into a guide hole 41 of the base 40. The guiding action of these two guide holes 41, 61 allows the roller guide 56 and the second roller 52 to slide in the Y direction.

[0028] 6, the screw mechanism 57 includes a fixed wall 57A fixed on the base 40, a nut 57B attached to the fixed wall 57A, and an adjustment screw 57C screwed into the nut 57B. The tip of the adjustment screw 57C is connected to a connecting plate 56C of the roller guide 56.

[0029] From the above, the adjustment screw 57C can be used to adjust the positions of the roller guide 56 and the second roller 52 in the Y direction. By adjusting the position of the second roller 52, the roller tube pitch of the two rollers 51, 52 can be adjusted.

[0030] The lock plate 65 is attached to the upper surface of the guide plate 60 as shown in FIG. 7. The lock plate 65 has four through holes. Bolts B are attached to the four through holes. By screwing each bolt B into the four bolt holes D of the roller guide 56, the roller guide 56 can be locked after adjusting the position of the second roller 52. Note that the bolt holes for tightening the lock plate 65 to the guide plate 60 have some play. This allows the position of the lock plate 65 to be adjusted according to the position of the roller guide 56.

[0031] As shown in Fig. 6, roller driving device 70 is made up of driving motor 71, motor gear 73, and roller gear 75. In this embodiment, of the pair of rollers 51, 52, first roller 51 is a driving roller and second roller 52 is a driven roller, and roller driving device 70 drives first roller 51. Roller driving device 70 corresponds to the "second driving device" of the present invention.

[0032] More specifically, the drive motor 71 is attached to the upper surface of the guide plate 60. The drive motor 71 may be of an electrically driven type or an air driven type.

[0033] The motor gear 73 is attached to the motor shaft of the drive motor 71, and the roller gear 75 is attached to the rotation shaft of the first roller 51. Therefore, when the drive motor 71 is driven, power is transmitted via the two gears 73 and 75, causing the first roller 51 to rotate.

[0034] Both the first roller 51 and the second roller 52 are made of metal (roller body). The first roller 51 has a coating layer 51A on its outer circumferential surface (contact surface with the U-shaped tube 1), and the friction of the outer circumferential surface of the roller is higher than that of the second roller 52. One example of the coating layer 51A is a urethane coating.

[0035] In this way, it is possible to prevent the first roller 51 from slipping against the U-shaped tube 1, and the U-shaped tube 1 can be fed and cut smoothly.

[0036] Furthermore, since the second roller 52 is a movable roller as described above, by adjusting the pitch between the rollers so that the U-shaped tube 1 is pressed against the first roller 51, it is possible to maintain contact between the first roller 51 and the U-shaped tube 1 during transport, thereby enabling even smoother feeding and cutting of the U-shaped tube 1.

[0037] When cutting the U-shaped tube 1, first, the position of the roller guide 56 is adjusted using the adjustment device 55 so that the distance between the two rollers 51, 52 matches the outer diameter dimension of the U-shaped tube 1. After that, the position of the roller guide 56 is locked by the lock plate 65.

[0038] Next, a start switch installed on the cutting device body 20 is operated to drive the drive motor 37 and the drive motor 71. When the drive motor 37 is driven, the band saw blade 35 starts to rotate, and when the drive motor 71 is driven, the first roller 51 starts to rotate.

[0039] Next, the U-shaped tube 1 is inserted between the first roller 51 and the second roller 52 from the front of the cutting device body 20 .

[0040] When the tip is inserted between the first roller 51 and the second roller 52, the U-shaped tube 1 is sandwiched from both sides in the Y direction by the first roller 51 and the second roller 52 and sent in the X direction. The U-shaped tube 1 sent in the X direction is cut by the band saw blade 35 and divided into two, left and right.

[0041] Figures 8 and 9 are diagrams showing the cutting process of the U-shaped tube 1. The bold line CT in Figures 8 and 9 is the cut line made by the band saw blade 35. Figure 8 shows the stage where about half of the U-shaped tube 1 has been cut off. Figure 9 shows the stage where point P on the U-shaped tube 1 has rotated to the cutting position. "1AX" is one of the cut U-shaped tubes, and "1AY" is the other cut U-shaped tube.

[0042] 8 and 9, in this configuration, at the cutting position by the band saw blade 35, a first roller 51 contacts the outer circumferential surface of the U-shaped tube 1, and a second roller 52 contacts the inner circumferential surface of the U-shaped tube 1. In this configuration, the first roller 51 and the second roller 52 provided on either side of the band saw blade 35 allow the U-shaped tube 1 to be fed along the tube axis V while positioning the center of the U-shaped tube 1 on the band saw blade 35. In this configuration, the orientation of the U-shaped tube 1 is always maintained so that at the cutting position by the band saw blade 35, the normal line LB to the tube axis V coincides with the band saw blade 35, so that the U-shaped tube 1 can be cut into two by the band saw blade 35 along the tube axis V.

[0043] Furthermore, cutting by the band saw blade 35 is not limited to the circular arc portion of the U-shaped tube 1, but it is also possible to cut a straight portion into two.

[0044] 3. Description of the rolling device 100 10 is a front view of the rolling apparatus 100, FIG. 11 is a plan view of the rolling apparatus 100, and FIG. 12 is a perspective view of the main part of the rolling apparatus 100. As shown in FIG.

[0045] The rolling device 100 includes a work table 110, a rolling device main body 120, a drive motor 170, a work guide 113, and a roller conveyor 115.

[0046] As shown in FIGS. 11 and 12, the rolling device body 120 and the drive motor 170 are disposed on the upper wall 110 A of the workbench 110 .

[0047] As shown in FIG. 11, the work guide 113 is located on the left side (entrance surface) of the rolling device body 120, and the roller conveyor 115 is located on the right side (discharge surface) of the rolling device body 120.

[0048] The rolling device main body 120 is a device that rolls the U-tube 1A, which has been divided into two by the U-tube cutting device 10, into a shape having a flat cross section.

[0049] As shown in FIG. 12, the rolling device body 120 has an introduction section 121 and a body frame 130.

[0050] The main body frame 130 is composed of a lower frame 131 and an upper frame 135, and has four stages of rolling rollers 150A to 150D arranged inside in the X direction (see FIG. 13).

[0051] 14 and 15, the rolling roller 150 is composed of a lower roller 151 and an upper roller 155. The lower roller 151 and the upper roller 155 are made of metal. The first to fourth lower rollers 151A to 151D are supported at both ends by two roller guides 132 and 133 fixed to the lower frame 131.

[0052] The roller width of the lower rollers 151A-151D increases in the order of the first, second, and third stages, with the third and fourth stages being the same width. When rolling the 1AX side of a U-shaped pipe cut by a U-shaped pipe cutting device, the first and second stages on the lower side are attached to the upper side, and the first and second stages on the upper side are swapped for the lower side, allowing the U-shaped pipe on the 1AX side to be supplied as smoothly as the 1AY.

[0053] Meanwhile, the first to fourth tiered upper rollers 155A-155D are supported at both ends by roller guides 137 having a U-shaped cross section that are fixed to upper frame 135. Four roller guides 137 are provided corresponding to the four upper rollers 155A-155D. Note that in Fig. 14, roller guide 137 is L-shaped, but part of the wall is omitted in order to show the rollers.

[0054] The roller widths of upper rollers 155A to 155D are the same from the first stage to the fourth stage, and are wide (the same width as lower rollers 151C and 151D in the third and fourth stages).

[0055] The rolling device body 120 has a gear mechanism 160. The gear mechanism 160 includes a first gear G1 to an eighth gear G8. The first gear G1 is disposed on the back side of the lower frame 131 (see FIG. 16). The first gear G1 meshes with the motor shaft of the drive motor 170.

[0056] The second gear G2 to the eighth gear G8 are disposed on the front side of the roller guide 132, as shown in Fig. 13. The second gear G2 is fixed to an end of the roller shaft of the first-stage lower roller 151A, and the fourth gear G4 is fixed to an end of the roller shaft of the second-stage lower roller 151B. The fourth gear G4 is a main gear coaxial with the first gear G1, that is, the first gear G1 is fixed to one side of the roller shaft of the second-stage lower roller 151B, and the fourth gear G4 is fixed to the other side.

[0057] The sixth gear G4 is fixed to an end of the roller shaft of the third-stage lower roller 151C, and the eighth gear G8 is fixed to an end of the roller shaft of the fourth-stage lower roller 151D.

[0058] The third gear G3 is located between the second gear G2 and the fourth gear G4 and meshes with both gears. The third gear G3 is an idle gear for transmitting power between the gears. The fifth gear G5 and the seventh gear G7 are also idle gears for transmitting power between the gears.

[0059] As a result of the above, the power of the drive motor 170 can be transmitted to each of the lower rollers 151A to 151D via each of the gears G1 to G8.

[0060] When rolling the U-shaped tube 1A cut into two pieces, first, the start switch of the workbench 110 is operated to drive the drive motor 170. When the drive motor 170 is driven, the lower rollers 151A to 151D rotate.

[0061] Next, the U-shaped tube 1A on the work guide 113 is inserted into the introduction section 121 with the cut surface facing upward. When the leading end of the U-shaped tube 1A reaches the first-stage rolling roller 150A, the U-shaped tube 1A is sandwiched from above and below between two rollers 151, 155 and sent in order to the subsequent rolling rollers 150B to 150D.

[0062] The U-shaped tube 1A is rolled into a flat plate by the rolling rollers 150A-150D at each stage, whereby curvature in the cross-sectional direction perpendicular to the tube axis is corrected. The rolled U-shaped tube 1B is then discharged from the rolling mill main body 120 onto a roller conveyor 115.

[0063] 4. Description of Leveler 200 Fig. 17 is a front view of the leveller 200, Fig. 18 is a plan view of the leveller 200, and Fig. 19 is a view seen from the direction A in Fig. 18. In Fig. 19, the drive motor 290 and gear covers 293 and 295 are omitted from the drawing.

[0064] The leveller 200 includes a work table 210, a leveller body 220, a drive motor 290, a first work guide 213 (introduction side), and a second work guide 215 (discharge side).

[0065] As shown in FIGS. 17 and 18, the leveller body 220 and the drive motor 290 are disposed on the upper wall 210 A of the workbench 210 .

[0066] The straightener body 220 is a device that straightens out the curvature of the rolled U-shaped tube 1B along the tube axis V (the longitudinal curvature of the rolled U-shaped tube 1B: see FIG. 1). The straightener 200 corresponds to the "straightening device" of the present invention.

[0067] 19 and 20, the leveller body 220 has a body frame 230. The body frame 230 is made up of a pair of side plates 231 and 233, and upper plates 235A to 235C.

[0068] 19, a first gear G1, a second gear G2, a third gear G3, a fourth gear G4, and a fifth gear G5 are attached to the outer surface of the side plate 231. The first gear G1 is a motor gear attached to the motor shaft of the drive motor 290.

[0069] The second gear G2 and the third gear G3 are attached to the roller shafts of the feed rollers 250A and 250B.

[0070] The fourth gear G4 and the fifth gear G5 are attached to the roller shafts of the discharge rollers 250C and 250D.

[0071] As shown in FIGS. 21 and 22, inside main body frame 230, there are arranged feed rollers 250A and 250B, a plurality of straightening rollers 260 and 270, and discharge rollers 250C and 250D.

[0072] The feed rollers 250A, 250B are located on the inlet side (right side in FIG. 22) of the main body frame 230 and face each other vertically. The lower feed roller 250A is supported by two side plates 231, 233 in a double-supported state.

[0073] The upper feed roller 250B is supported at both ends by a roller guide 255 having a U-shaped cross section.

[0074] The roller guide 255 is supported on the upper plate 235A so as to be vertically movable via an axis pin 256. A spring 257 is attached to the axis pin 256 and biases the roller guide 255 and the feed roller 250B downward.

[0075] The straightening rollers 260, 270 are made of metal. The straightening rollers 260, 270 are configured in two stages, upper and lower, with five straightening rollers 260A to 260E arranged in the lower stage and four straightening rollers 270A to 270D arranged in the upper stage.

[0076] The five straightening rollers 260A to 260E arranged in the lower tier are supported in a double-supported state by two side plates 231, 233. The five straightening rollers 260A to 260E arranged in the lower tier are arranged at approximately equal intervals in the X direction.

[0077] The four straightening rollers 270A to 270D arranged in the upper stage are supported at both ends by a U-shaped cross section roller guide 275. The roller guide 275 is attached to the upper plate 235B, and four roller guides 275 are provided corresponding to the four straightening rollers 270A to 270D.

[0078] An adjustment screw 278 is attached to the upper plate 235B in correspondence with each roller guide 275, and the adjustment screws 278 are used to adjust the vertical positions of each roller guide 275 and the correction roller 270.

[0079] The four straightening rollers 270A to 270D arranged in the upper stage are respectively disposed between the straightening rollers 260A to 260E in the lower stage.

[0080] Specifically, the straightening roller 270A is disposed at a midpoint between the two straightening rollers 260A and 260B, and the straightening roller 270B is disposed at a midpoint between the two straightening rollers 260B and 260C.

[0081] Further, the straightening roller 270C is disposed at a midpoint between the two straightening rollers 260C and 260D, and the straightening roller 270D is disposed at a midpoint between the two straightening rollers 260D and 260E.

[0082] The position of the center O of the straightening rollers 270A-270D becomes lower from the downstream side to the upstream side (from left to right in FIG. 22). In other words, the overlapping area between each of the straightening rollers 270A-270D and the lower straightening rollers 260A-260E becomes larger from the downstream side to the upstream side. The overlapping area is the vertical overlapping area between the upper apex of the lower straightening roller 260 and the lower apex of the upper straightening roller 270.

[0083] By providing an overlap between the upper and lower straightening rollers 260, 270, as shown in FIG. 22, the U-shaped tube 1B can be warped in the direction opposite to the curvature of the tube axis V, thereby straightening the curvature of the U-shaped tube 1B along the tube axis V.

[0084] The leveller body 220 has a sixth gear G6 to an eighteenth gear G18 on the outer surface of the side plate 233, as shown in FIGS.

[0085] The sixth gear G6 is attached to the roller shaft of the feed roller 250A. The eighth gear G8, the tenth gear G10, the twelfth gear G12, the fourteenth gear G14, and the sixteenth gear G16 are attached to the roller shafts of the correction rollers 260A to 260E, respectively. The eighteenth gear G18 is attached to the roller shaft of the discharge roller 250C.

[0086] The seventh gear G7 is located between the sixth gear G6 and the eighth gear G8 and meshes with both gears. The seventh gear G7 is an idle gear for transmitting power between the gears. The ninth gear G9 is located between the eighth gear G8 and the tenth gear G10 and meshes with both gears. The ninth gear G9 is an idle gear for transmitting power between the gears.

[0087] The eleventh gear G11, the thirteenth gear G13, the fifteenth gear G15, and the seventeenth gear G17 are also idle gears for transmitting power between the gears.

[0088] From the above, the power of the drive motor 290 can be transmitted to the feed rollers 250A, 250B, the lower correction rollers 260A to 260E, and the discharge rollers 250C, 250D via the gears G1 to G18.

[0089] When straightening the curvature of the U-shaped tube 1B along the tube axis V, first, the start switch of the workbench 210 is operated to drive the drive motor 290. By driving the drive motor 290, the above-mentioned feed rollers 250A, 250B, the lower straightening rollers 260A to 260E, and the discharge rollers 250C, 250D are rotated.

[0090] Next, the U-shaped tube 1B on the first work guide 213 is inserted between the two feed rollers 250A, 250B with the curved surface facing up, as shown in Fig. 22. When the leading end of the U-shaped tube 1B reaches between the feed rollers 250A, 250B, the U-shaped tube 1B is sandwiched from above and below by the two feed rollers 250A, 250B and sent to the subsequent straightening rollers 260, 270.

[0091] The U-shaped tube 1B has its curvature along the tube axis V straightened as it passes between the straightening rollers 260, 270. The U-shaped tube 1C, which has been straightened into a flat plate, is then discharged onto the second work guide 215 via the discharge rollers 250C, 250D.

[0092] 5. Description of the decontamination device 300 23 is a front view of the decontamination apparatus 300, FIG. 24 is a plan view of the decontamination apparatus 300, and FIGS. 25 and 26 are perspective views of the main parts of the decontamination apparatus 300. As shown in FIG.

[0093] The decontamination apparatus 300 includes a work table 310 , a decontamination apparatus main body 320 , a work guide 313 , and a roller conveyor 315 .

[0094] As shown in FIGS. 24 and 25, the decontamination apparatus main body 320 is disposed on the upper wall 310A of the workbench 310.

[0095] As shown in FIG. 24, the work guide 313 is located on the left side surface (introduction surface) of the decontamination apparatus main body 320, and the roller conveyor 315 is located on the right side surface (discharge surface) of the decontamination apparatus main body 320.

[0096] The decontamination apparatus main body 320 is an apparatus for decontaminating the surface of the U-shaped tube 1C that has been processed into a flat plate shape by the leveller 200.

[0097] As shown in FIG. 26, the decontamination apparatus main body 320 includes a base plate 330, a blast box 350, a transport section 400, a blast head 500, a coupling section 600, and a connection section 700.

[0098] The base plate 330 is for fixing to the workbench 310. In the center of the base plate 330, a through hole for passing the blast material B is formed.

[0099] The blast box 350 is a box-shaped opening at the bottom, and is made up of four side walls 360A-360D and a ceiling wall 370. A through hole 371 is provided in the center of the ceiling wall 370 (see FIG. 33). The first side wall 360A faces the second side wall 360C, and the third side wall 360B faces the fourth side wall 360D. In FIGS. 26 and 27, the reference numerals for the second side wall 360C and the fourth side wall 360D are omitted.

[0100] A flange 355 is provided on the bottom of the blast box 350. The blast box 350 is fixed to the base plate 330 via the flange 355.

[0101] The first side wall 360A of the blast box 350 is an introduction surface for the workpieces, and the second side wall 360C is a discharge surface for the workpieces. The first side wall 360A has an opening (inlet) for introducing the workpieces, and the second side wall 360C has an opening (outlet) for discharging the workpieces.

[0102] The transport section 400 is composed of a first transport section 400A and a second transport section 400C. The first transport section 400A is located in front of the first side wall 360A, and includes a roller panel 405, a movable plate 408, a first roller 410, a second roller 420, and a drive motor 450, as shown in Figs.

[0103] 27, the roller panel 405 is L-shaped and is fixed to the front of the first side wall 360A. The movable plate 408 is supported on the top wall 407 of the roller panel 405 via shaft pins 407A and 407B so as to be vertically movable. A coil spring 409 is provided between the top wall 407 and the movable plate 408. The coil spring 409 urges the movable plate 408 downward.

[0104] The first roller 410 is fixed to the front wall of the roller panel 405 via a first roller holder 415. The second roller 420 is fixed to the movable plate 408 via a second roller holder 425. The second roller 420 is a movable roller that can move in the vertical direction. The two rollers 410, 420 face each other vertically. The second roller 420 is biased by a coil spring 409 so as to come into contact with the first roller 410.

[0105] 28, the drive motor 450 is attached below the first roller 410. A first gear G1 is attached to the motor shaft of the drive motor 450. The first gear G1 meshes with a second gear G2 fixed to the shaft end of the first roller, and the second gear G2 meshes with a third gear G3 fixed to the shaft end of the second roller.

[0106] As a result, the power of the drive motor 450 can be transmitted to the first roller 410 and the second roller 420 via the gears G1-G3. The structure of the second conveying section 400C is the same as that of the first conveying section 400A. In addition, the first conveying section 400A and the second conveying section 400C are each provided with sensors S1 and S2 that detect the U-shaped tube 1C (see FIG. 29).

[0107] As shown in FIG. 29, a work introduction section 380A is provided between the first transport section 400A and the first side wall 360A, and a work discharge section 380B is provided between the second transport section 400C and the second side wall 360C.

[0108] The workpiece introduction section 380A has an introduction port for the U-shaped tube 1C. A brush 383 and a guide roller 385 are provided at the introduction port. The brush 383 prevents contaminants decontaminated from the U-shaped tube 1C from leaking out from the introduction port. The guide roller 385 is for guiding the U-shaped tube 1C.

[0109] The work discharge section 380C has almost the same structure as the work introduction section 380A. The work discharge section 380C has a discharge port for the U-shaped tube 1C. A brush 383 and a guide roller 385 are provided at the discharge port. The brush 383 prevents contaminants decontaminated from the U-shaped tube 1C from leaking out of the discharge port. The guide roller 385 is for guiding the U-shaped tube 1C.

[0110] As shown in Figures 29 and 34, a blast head 500 is attached to the ceiling wall 370 of the blast box 350 via a connecting part 600. The blast head 500 is cylindrical with an axial hole 500A penetrating vertically, and a blast nozzle 510 is attached to the tip. The blast nozzle 510 has a thin tubular tip and has a nozzle hole 511 along the axis. The nozzle hole 511 communicates with the axial hole 500A of the blast head 500, and the blast material B passes through the axial hole 500A and the nozzle hole 511 and is ejected from the nozzle tip.

[0111] The blast head 500 is connected to an air blast device 550 via a blast hose 530. The air blast device 550 is a device that sprays blast material B (abrasive material) (see FIG. 30). The air blast device 550 may be of a direct pressure type or a vacuum type.

[0112] The direct pressure type is a type in which compressed air is sent into a blast tank 560 containing blast material B, the blast material B and the compressed air are mixed at the bottom of the tank, and the blast material B is sprayed at high pressure together with the compressed air.

[0113] The vacuum type blows compressed air from a nozzle like a spray bottle, sucking up blast material B with an ejector effect and mixing the blast material B with the blown compressed air.

[0114] In this embodiment, a direct pressure type with excellent abrasive cleaning power is used. Although alumina is used as the blasting material B, iron-based (steel shot, steel grid, reduced iron powder, etc.), plastic-based (polyplus, polyextra, nylon, etc.), and plant-based (walnut, peach, corn, etc.) materials can also be used instead.

[0115] In this embodiment, as shown in Fig. 29, a rubber protective layer 365 is provided on the inner surface of the blast box 350. The protective layer 365 is provided on the four inner surfaces of the blast box 350. By providing the protective layer 365, the blast box 350 can be protected from the blast material B, and wear of the inner surface can be suppressed.

[0116] As shown in Figs. 31 to 33, the connecting portion 600 is made up of a base 610, a fixing plate 620, a boss portion 630, and four outer wall portions 650A to 650D.

[0117] Mount 610 is made of metal, and is fixed to ceiling wall 370 of blast box 350. Mount 610 has a rectangular shape in a plan view, and has through-hole 611 in the center. Furthermore, four peripheral walls 615A to 615D are provided on mount 610 and surround the entire periphery.

[0118] Fixed plate 620 is a rectangular metal plate. An annular holding member 625 is provided in the center of fixed plate 620. Bolt holes 627 are formed in holding member 625. Bolt holes 627 are provided so as to penetrate holding member 625 from its outer circumferential surface to its inner circumferential surface.

[0119] Boss portion 630 has a cylindrical shape, and is provided at four locations corresponding to the four corners of fixed plate 620. Boss portion 630 is located between base 610 and fixed plate 620, and supports fixed plate 620 at a position spaced apart from base 610 by the height of boss portion 630.

[0120] 32, the four outer wall portions 650A-650D are composed of a metal base portion 660 and a brush portion 670. The brush portion 670 is made of brush bristles made of synthetic fiber, metal fiber, or natural fiber, and is fixed to the base portion 660. The four outer wall portions 650A-650D are each fixed to the four side surfaces of the fixing plate 620 with bolts via fasteners 680.

[0121] As shown in FIG. 33, the fixing plate 620, the boss portion 630, and the stand 610 are fixed to the ceiling wall 370 by a bolt B which passes through them vertically.

[0122] In this embodiment, a rubber spacer 375 is interposed between the stand 610 and the ceiling wall 370 to eliminate any gap between them and improve adhesion.

[0123] 34, the blast head 500 has a stepped portion 501 at the tip. The blast head 500 can be positioned in the axial direction (up and down direction) by fitting the stepped portion 501 into the holding member 625. Then, the blast head 500 can be prevented from coming off the holding member 625 by inserting the bolt BS into the bolt hole 627 and tightening it.

[0124] The blast nozzle 510 penetrates the fixed plate 620 , and a nozzle tip 510 A for ejecting the blast material B faces the inside of a through hole 611 of the stand 610 .

[0125] The outer walls 650A-650D surround the entire periphery of the blast nozzle 510. Since the outer walls 650A-650D are made of brushes, when the blast nozzle 510 sprays the blast material B at high pressure, outside air is taken into the inside of the stand 610 through the outer peripheral walls 650A-650D, and a downward airflow is generated inside the blast box (FIG. 34).

[0126] Further, a lower end portion 651 of the outer wall portion 650 is fitted inside a peripheral wall 615 of the stand 610 , and the outer wall portion 650 overlaps with the stand 610 by the height of the peripheral wall 615 .

[0127] This makes it possible to reduce the gap between the outer wall portion 650 and the stand 610, making it difficult for contaminants to leak to the outside.

[0128] The connection part 700 is a tubular joint, and is flange-coupled to the lower surface of the base plate 330. The connection part 700 communicates with the inside of the blast box 350 via the through-hole 331 of the base plate 330.

[0129] The inner diameter of the connection part 700 becomes smaller from the top to the bottom. A suction hose 750 for sucking up the blasting material B is flanged to the tip of the connection part 700. A vacuum device (not shown) is connected to the hose 750, and the blasting material B inside the blasting box 350 can be collected.

[0130] When decontaminating the U-shaped pipe 1C processed into a flat plate shape, first, the start switch of the workbench 310 is operated to drive the drive motor 450. When the drive motor 450 is driven, the rollers 410, 420 of the first transfer section 400A and the second transfer section 400B rotate.

[0131] Next, the U-shaped tube 1C on the work guide 313 is inserted between the rollers 410, 420 of the first conveyor section 400A with the surface to be decontaminated (the inner surface of the tube) facing upward. When the tip of the U-shaped tube 1C reaches between the rollers, the U-shaped tube 1C moves inside the blast box 350 while being sandwiched between the two rollers 410, 420 from above and below.

[0132] While moving through the blast box 350, contaminants on the surface of the U-shaped tube 1C are removed by high-pressure spraying of blast material B from the blast head 500 onto the surface of the U-shaped tube 1C. The decontaminated U-shaped tube 1D is discharged onto the roller conveyor 315 from the second transport section 400B.

[0133] As explained above, by using the decontamination line L, the following four tasks can be performed in an assembly line, which improves workability. (1) Cutting the U-tube 1 into two pieces along the tube axis V (2) Rolling the U-tube 1A cut into two pieces (3) The operation of straightening the curvature of the U-shaped tube 1B along the tube axis V after rolling. (4) Decontamination of U-tube 1C after straightening

[0134] 6.Effects In this configuration, the U-shaped tube 1, whose tube axis V is curved, can be cut into two along the tube axis V. Therefore, it is possible to decontaminate not only the straight pipe section but also the bent pipe section of the contaminated pipe, so that the contaminated pipe can be efficiently disposed of.

[0135] <Other embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included within the technical scope of the present invention.

[0136] (1) In the above embodiment, the U-shaped pipe cutting device 10 is used as part of the decontamination line L, but it can also be used alone. In addition, the use is not limited to the removal and dismantling of decontamination piping, and it can be used for other purposes. In addition, the object to be cut is not limited to the U-shaped pipe 1, and it can be widely applied to any bent pipe (particularly preferably made of metal, but also of materials such as resin). The bent pipe is not limited to a circular arc, and any shape is acceptable as long as the pipe axis V is curved.

[0137] (2) In the above embodiment, the first roller 51 is driven and the second roller 52 is driven. Both the first roller 51 and the second roller 52 may be driven. Also, a coating layer may be provided on the surface of the second roller 52. Both the first roller and the second roller may be driven, and the U-shaped tube may be pushed in by hand. In this case, the drive motor 71 can be omitted.

[0138] (3) In the above embodiment, the rollers having the function of feeding the U-tube 1 are only the first roller 51 and the second roller 52, and no other rollers for feeding are provided. Other rollers for feeding may also be provided.

[0139] (4) In the above embodiment, the decontamination line L is composed of four devices: the U-shaped tube cutting device 10, the rolling device 100, the leveller 200, and the decontamination device 300. As for each device, the U-shaped tube cutting device 10 may have a different configuration as long as it is a device capable of cutting the U-shaped tube into two along the tube axis. Similarly, the rolling device 100, the leveller 200, and the decontamination device 300 may have a different configuration as long as they are devices capable of performing the required functions. [Explanation of symbols]

[0140] 1 U-tube 10 U-shaped tube cutting device 35 Bandsaw Blade 37 Drive motor 51 First roller (drive roller) 52 Second roller (driven roller) 56 Roller guide 71 Drive motor 100 Rolling equipment 200 Levela (corrective device) 300 Decontamination Equipment

Claims

1. A cutting device for cutting a bent pipe into two pieces along the pipe axis, comprising: An endless band saw blade; A first drive device that drives the band saw blade in an up-down orbit; a pair of rollers located on either side of the band saw blade and in contact with either side of an outer circumferential surface of the bent tube at a cutting position by the band saw blade; a second drive device that drives and rotates at least one of the pair of rollers, A cutting device that uses the pair of rollers to position and feed the bent tube relative to the band saw blade, and cuts the bent tube into two pieces using the band saw blade.

2. 2. The cutting device of claim 1, Of the pair of rollers, One is a driving roller and the other is a driven roller. the driving roller has a coating layer on an outer peripheral surface thereof, the coating layer having a higher friction than the driven roller; A cutting device, wherein the driven roller is a movable roller whose roller axis position is adjustable.

3. A cutting method for cutting a bent pipe into two pieces along a pipe axis, comprising the steps of: A cutting method in which a bent tube is positioned relative to a band saw blade and fed out using a pair of rollers located on either side of the band saw blade, and then cut into two pieces by the band saw blade.

4. A decontamination line for contaminated piping, A cutting device that cuts the U-shaped contaminated pipe into two along the pipe axis; a rolling device for rolling the contaminated pipe cut into two pieces along the pipe axis; a straightening device for straightening a curvature of the contaminated pipe along its pipe axis after rolling; A decontamination line comprising a decontamination device that decontaminates the surface of the contaminated pipe after the curve has been corrected.

5. 5. The decontamination line according to claim 4, The decontamination line, wherein the cutting device is the cutting device according to claim 1 or 2.

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