Cutting device

Abstract

To provide a cutting device enabling a cutting position to be highly flexibly selected.SOLUTION: A cutting device 20 comprises: a support mechanism 21 having a plurality of support frames 26 each of which is extendable and contractible in a radial direction of a steel pipe portion 11; a cutting mechanism 22 comprising a plurality of cutting frames 46 each of which is extendable and contractible in a radial direction of the steel pipe portion 11 and has a cutting blade at distal end thereof; a connection portion 24 which rotatably connects a central portion of the cutting mechanism 22 to a central portion of the cutting mechanism 21; and a rotating mechanism 23 which rotates the cutting mechanism 22 around a central axis line of the steel pipe portion 11, with respect to the support mechanism 21.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cutting device for cutting a large-diameter steel pipe part used in an offshore wind power generation device or the like from the inside.

Background Art

[0002] Conventionally, as a structure of an offshore wind power generation device, a fixed-bottom type in which a wind power generator is fixed and supported on a foundation structure installed on the seabed is known. The fixed-bottom type foundation structure is constructed, for example, by a large-diameter pile (support column, monopile) having a steel pipe part whose lower end side is fixed to the seabed and extending from the sea to above the sea surface.

[0003] By the way, when disassembling this type of offshore wind power generation device, it is also necessary to remove the above-mentioned large-diameter pile. Since it is difficult to remove the large-diameter pile as it is, for example, the long steel pipe part is cut at a desired position and removed piece by piece.

[0004] As a cutting device applicable to cutting such a large-diameter pile, Patent Document 1 discloses a cutting device capable of cutting a steel pipe part from the inside of the steel pipe part. The cutting device described in Patent Document 1 is supported via a support assembly having a plurality of legs with respect to a plate-shaped platform extending in the cross-sectional direction of the steel pipe part.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, since the cutting device described in Patent Document 1 is supported on a platform via a support assembly, the cutting position depends on the position of the platform. Therefore, it was necessary to install a platform in order to cut at the desired position. [Means for solving the problem]

[0007] A cutting device that solves the above problems comprises a support mechanism having a plurality of support frames that are extendable and retractable in the radial direction of the steel pipe; a cutting mechanism having a plurality of cutting frames configured to be extendable and retractable in the radial direction of the steel pipe and having cutting blades at their tips; a connecting part that rotatably connects the center of the cutting mechanism to the center of the support mechanism; and a rotation mechanism that rotates the cutting mechanism around the central axis of the steel pipe relative to the support mechanism. [Effects of the Invention]

[0008] According to the present invention, the degree of freedom regarding the cutting position when cutting the steel pipe section can be increased. [Brief explanation of the drawing]

[0009] [Figure 1] A side view showing a schematic configuration of one embodiment of a cutting device. [Figure 2] A top view showing the schematic configuration of the cutting device. [Figure 3] (a) A diagram showing the approximate configuration of the support frame when it is at its shortest length, with some members shown in cross-section; (b) A diagram showing the approximate configuration of the support frame when it is at its pressing length, with some members shown in cross-section. [Figure 4] A top view showing the schematic configuration of the support mechanism when it is in the pressed position. [Figure 5] A bottom view showing the schematic configuration of the cutting device. [Figure 6] (a) A diagram showing the general configuration of the cutting frame when it is at its shortest length, with some members shown in cross-section; (b) A diagram showing the general configuration of the cutting frame when it is at its cutting length, with some members shown in cross-section; (c) A diagram showing the general configuration of the cutting frame when it is at its cutting length, with the cutting blade at its maximum protrusion, with some members shown in cross-section. [Figure 7] A top view showing the operation of the link mechanism when the cutting frame is extended or retracted. [Figure 8] A partially enlarged view showing the area around the rotation mechanism in Figure 1. [Figure 9] A side view showing a schematic configuration of the support frame when it has been extended to its pressed length. [Figure 10] A side view showing a schematic configuration of the cutting frame when extended to the cutting length. [Modes for carrying out the invention]

[0010] An embodiment of the cutting device will be described with reference to Figures 1 to 10. As shown in Figure 1, the cutting device 20 is a device for cutting steel pipe sections 11, such as large-diameter cylindrical piles (support columns, monopiles) used in offshore wind power generation equipment, from the inside. The cutting device 20 is suspended by a crane or the like and moves up and down inside the steel pipe section 11 to be positioned at the desired cutting location.

[0011] The cutting device 20 includes a support mechanism 21, a cutting mechanism 22, and a rotation mechanism 23. The cutting mechanism 22 is located below the support mechanism 21. The support mechanism 21 and the cutting mechanism 22 are connected at their centers via a connecting portion 24. The connecting portion 24 rotatably connects the cutting mechanism 22 to the support mechanism 21. The rotation mechanism 23 is located between the support mechanism 21 and the cutting mechanism 22 and is provided around the connecting portion 24. The rotation mechanism 23 rotates the cutting mechanism 22 in forward and reverse directions relative to the support mechanism 21, with the rotation axis 22A as the center of rotation.

[0012] (Support mechanism) As shown in Figure 2, the support mechanism 21 has a plurality of support frames 26 extending radially from its center to the steel pipe section 11. Each support frame 26 is configured to be expandable and contractible in the radial direction of the steel pipe section 11. The plurality of support frames 26 are connected at the center of the support mechanism 21 and are provided at equal intervals around the rotation axis 22A of the cutting mechanism 22. The support mechanism 21 in this embodiment has eight support frames 26.

[0013] As shown in Figures 3(a) and 3(b), the support frame 26 has an inner support frame 31 and an outer support frame 32. The inner support frame 31 has a cylindrical shape. The outer support frame 32 is inserted into the inner support frame 31. The support frame 26 expands and contracts between the shortest length shown in Figure 3(a) and the pressing length shown in Figure 3(b) as the outer support frame 32 moves along the extending direction of the inner support frame 31. The inner support frame 31 is provided with a wire engagement portion (not shown) to which a crane's lifting wire or the like can be engaged.

[0014] The support mechanism 21 has a support jack 33 on each support frame 26 that moves the outer support frame 32 relative to the inner support frame 31. The support jack 33 includes a support cylinder 34 and a support rod 35. The support cylinder 34 and the support rod 35 extend along the extending direction of the inner support frame 31. In this embodiment, the support cylinder 34 is fixed to the upper surface of the inner support frame 31. The tip of the support rod 35 is fixed to the upper surface of the outer support frame 32. The support jack 33 extends and retracts the support frame 26 by moving the support rod 35 along the extending direction of the inner support frame 31 relative to the support cylinder 34.

[0015] The support jack 33 is provided with hydraulic pressure supply and discharge by a hydraulic pressure supply machine 37 (see FIGS. 1 and 2) installed on the upper surface of the central part of the support mechanism 21. As a result, the support rod 35 moves forward and backward (extends and contracts) along the extending direction of the support cylinder 34. The support jacks 33 of each support frame 26 are configured such that the same hydraulic pressure is supplied and discharged from the hydraulic pressure supply machine 37. Thereby, the expansion and contraction amounts of each support frame 26 can be made the same.

[0016] A pressing member 40 is detachably attached to the tip of the outer support frame 32. The pressing member 40 is a part that is pressed against the inner peripheral surface 11a of the steel pipe part 11 when the support frame 26 extends. The pressing member 40 has a contact part (pressing part) 41 that is pressed against the inner peripheral surface 11a of the steel pipe part 11 and adheres to the steel pipe part 11 on the extension direction side of the support frame 26. The contact part 41 is constituted by an elastic member. The contact part 41 has a contact surface (pressing surface) 41a that presses against and adheres to the inner peripheral surface 11a of the steel pipe part 11. The contact surface 41a is formed in an arc surface shape that protrudes outward (toward the inner peripheral surface 11a side) along the inner peripheral surface 11a of the steel pipe part 11.

[0017] As shown in FIG. 4, in the support mechanism 21, when hydraulic pressure is supplied from the hydraulic pressure supply machine 37 to the support jack 33, each support frame 26 extends radially outward of the steel pipe part 11. Then, when the support frame 26 extends to the pressing length, the contact part 41 of the pressing member 40 is pressed against the steel pipe part 11 and adheres to the inner peripheral surface 11a of the steel pipe part 11. As a result, the cutting device 20 is supported by the steel pipe part 11. The cutting device 20 supported by the steel pipe part 11 is arranged such that the rotation axis 22A of the cutting mechanism 22 coincides (including substantially coincides) with the central axis of the steel pipe part 11.

[0018] (Cutting mechanism) As shown in Figure 5, the cutting mechanism 22 has a plurality of cutting frames 46 that extend radially from its center to the steel pipe section 11. The plurality of cutting frames 46 are connected at the center of the cutting mechanism 22 and are provided at equal intervals around the rotation axis 22A of the cutting mechanism 22. The cutting mechanism 22 in this embodiment has eight cutting frames 46.

[0019] As shown in Figures 6(a), 6(b), and 6(c), each cutting frame 46 is configured to be expandable and contractible in the radial direction of the steel pipe section 11. Specifically, the cutting frame 46 has an inner cutting frame 47 and an outer cutting frame 48. The inner cutting frame 47 has a cylindrical shape. The outer cutting frame 48 has a cylindrical frame body 49 that is inserted into the inner cutting frame 47. The cutting frame 46 expands and contracts between the shortest length shown in Figure 6(a) and the cutting length shown in Figures 6(b) and 6(c) by the movement of the frame body 49 of the outer cutting frame 48 along the extending direction of the inner cutting frame 47. The cutting length is the length at which the tip surface of the outer cutting frame 48 and the inner circumferential surface 11a of the steel pipe section 11 face each other at a predetermined distance apart.

[0020] The cutting mechanism 22 has cutting jacks 50 on each cutting frame 46 that move the outer cutting frame 48 relative to the inner cutting frame 47. The cutting jacks 50 have a cutting cylinder 51 and a cutting rod 52. The cutting cylinder 51 and the cutting rod 52 extend along the extending direction of the inner cutting frame 47.

[0021] In this embodiment, the cutting cylinder 51 is fixed to the lower surface of the inner cutting frame 47. The tip of the cutting rod 52 is fixed to the lower surface of the outer cutting frame 48. The cutting jack 50 extends and retracts the cutting frame 46 by moving the cutting rod 52 back and forth relative to the cutting cylinder 51.

[0022] The cutting jack 50 receives and discharges hydraulic pressure from the hydraulic supply unit 37 (see Figures 1 and 2), which causes the cutting rod 52 to move forward and backward (extend and retract) along the extending direction of the cutting cylinder 51. The cutting jack 50 of each cutting frame 46 is configured to receive and discharge the same hydraulic pressure from the hydraulic supply unit 37. This makes it possible to make the extension and retraction amount of each cutting frame 46 the same. Note that the hydraulic supply unit 37 used for the cutting jack 50 and the hydraulic supply unit 37 used for the support jack 33 may be separate hydraulic supply units.

[0023] As shown in Figures 6 and 7, the outer cutting frame 48 has a link connecting member 55 at its tip. The link connecting member 55 is the part to which the link mechanism 65, described later, is connected. The link mechanism 65 is a mechanism that connects the tips of a pair of adjacent cutting frames 46 around the rotation axis 22A of the cutting mechanism 22.

[0024] The link connecting member 55 is formed in a convex arc shape on the radially outward side (inner surface 11a side) of the steel pipe section 11, so as to follow the inner surface 11a of the steel pipe section 11. The links (66, 67) that constitute the link mechanism 65 are connected to the portion of the link connecting member 55 that protrudes from the frame body 49 in the rotational direction of the cutting mechanism 22.

[0025] The cutting frame 46 has a cutting blade 57 at the tip of the outer cutting frame 48. The amount of protrusion of the cutting blade 57 from the link connecting member 55 can be adjusted by the cutting blade adjustment mechanism 58. In this embodiment, the cutting blade adjustment mechanism 58 is provided inside the frame body 49 of the outer cutting frame 48.

[0026] The cutting blade adjustment mechanism 58 includes a cutting blade cylinder 59 and a cutting blade rod 60. The cutting blade cylinder 59 and the cutting blade rod 60 extend along the extending direction of the frame body 49. The cutting blade cylinder 59 is fixed, for example, to the inner surface of the frame body 49. A cutting blade 57 is detachably attached to the tip of the cutting blade rod 60.

[0027] The cutting blade adjustment mechanism 58 allows the cutting blade rod 60 to move back and forth along the extending direction of the frame body 49 relative to the cutting blade cylinder 59. This makes it possible to move the cutting blade 57 between the retracted position shown in Figures 6(a) and 6(b) and the maximum protruding position shown in Figure 6(c).

[0028] The cutting blade adjustment mechanism 58 moves the cutting blade rod 60 as hydraulic pressure is supplied and discharged by the hydraulic supply unit 37. The cutting blade adjustment mechanism 58 of each cutting frame 46 is configured to receive the same hydraulic pressure from the hydraulic supply unit 37. This makes it possible to make the protrusion amount of the cutting blade 57 the same for each cutting frame 46.

[0029] (Link mechanism) As shown in Figure 7, the link mechanism 65 is detachably connected to a pair of cutting frames 46. The link mechanism 65 has a first link 66 and a second link 67. In this embodiment, the first link 66 is a plate-shaped link connected to the cutting frame 46 located on the clockwise side. The second link 67 is a plate-shaped link connected to the cutting frame 46 located on the counterclockwise side. In this embodiment, the first link 66 and the second link 67 are formed in a convex arc shape on the radially outward side (inner circumferential surface 11a side) of the steel pipe section 11 in the state shown in Figure 7 (corresponding to the storage position shown in Figure 6(b) and the maximum protruding position shown in Figure 6(c)). Furthermore, the multiple first links 66 and the multiple second links 67 of this embodiment are arranged along the inner circumferential surface 11a of the steel pipe section 11 in the state shown in Figure 7, and are configured to form an annular shape.

[0030] The base end of the first link 66 is detachably connected to one of the pair of cutting frames 46 so as to be able to rotate in forward and reverse directions around a first base end rotating shaft portion 68 that extends vertically as the center of rotation. The base end of the second link 67 is detachably connected to the other of the pair of cutting frames 46 so as to be able to rotate in forward and reverse directions around a second base end rotating shaft portion 69 that extends vertically as the center of rotation. The tip portions of the first link 66 and the tip portions of the second link 67 are rotatably connected around a tip rotating shaft portion 70 that extends vertically as the center of rotation.

[0031] The first link 66 and the second link 67 are positioned along the steel pipe section 11 when the cutting frame 46 is at the cutting length. That is, as described above, the multiple first links 66 and the multiple second links 67 of this embodiment are arranged to form an annular shape along the inner circumferential surface 11a of the steel pipe section 11 in the state shown in Figure 7 (corresponding to the storage position shown in Figure 6(b) and the maximum protruding position shown in Figure 6(c)). Furthermore, the tips of the first links 66 and the second links 67 are biased toward the center of the cutting mechanism 22. The biasing force of each link 66, 67 may be applied by a biasing member provided at the base end, or by a biasing member connecting the tip of one link to the center of the cutting mechanism 22. Due to these biasing forces, when the cutting frame 46 is not at the cutting length, the first link 66 and the second link 67 bend inward radially in the steel pipe section 11 in accordance with the expansion and contraction of the cutting frame 46, as shown by the dashed line in Figure 7. The tip rotating shaft section 70 moves along the line bisector of the angle formed by the pair of cutting frames 46 in accordance with the expansion and contraction of the cutting frame 46.

[0032] In the cutting mechanism 22 with this configuration, when hydraulic pressure is supplied to the cutting jack 50 from the hydraulic supply unit 37, each cutting frame 46 extends radially outward from the steel pipe section 11. When the cutting frames 46 extend to the cutting length, the rotation mechanism 23 is driven and the cutting mechanism 22 rotates around the rotation axis 22A as the center of rotation. Then, hydraulic pressure is supplied to the cutting blade adjustment mechanism 58 from the hydraulic supply unit 37, gradually increasing the amount of protrusion of the cutting blade 57 as it rotates. As a result, the cutting blade 57 cuts into the steel pipe section 11 as it rotates, and the steel pipe section 11 is cut by the cutting mechanism 22.

[0033] (Rotation mechanism) As shown in Figure 8, the rotating mechanism 23 has a driven gear 73, a plurality of drive gears 74, and a plurality of drive units 75.

[0034] The driven gear 73 is fixed, for example, to the upper surface of the inner cutting frame 47 of the cutting frame 46. The driven gear 73 is an annular spur gear having a tooth profile on its outer circumference. The driven gear 73 is provided between the support mechanism 21 and the cutting mechanism 22, coaxially surrounding the connecting portion 24.

[0035] The multiple drive gears 74 are spur gears having tooth profiles on their outer circumference that mesh with the driven gears 73. The multiple drive gears 74 are arranged symmetrically around the rotation axis 22A of the cutting mechanism 22 in a top view of the cutting device 20, for example. The rotation mechanism 23 of this embodiment has two drive gears 74. Each drive gear 74 is connected to the output shaft 75A of the drive unit 75. Each drive gear 74 rotates in forward and reverse directions around a rotation axis that extends vertically by the forward and reverse drive of the drive unit 75.

[0036] The drive unit 75 is provided in correspondence with each of the multiple drive gears 74. The drive unit 75 is fixed, for example, to the lower surface of the support frame 26. In this embodiment, the drive unit 75 is positioned symmetrically around the rotation axis 22A of the cutting mechanism 22 when viewed from above the cutting device 20. The drive unit 75 rotates the drive gears 74 so that the driven gear 73 rotates in forward and reverse directions in a predetermined rotational direction when hydraulic pressure is supplied from the hydraulic supply unit 37.

[0037] (Cutting procedure) The procedure for cutting the steel pipe section 11 using the cutting device 20 will be described below. First, the cutting device 20 is transported into the steel pipe section 11. Specifically, with the support frame 26 and cutting frame 46 at their shortest lengths, the cutting device 20 is transported into the steel pipe section 11 using a crane or the like. Then, the cutting device 20 is lowered to a predetermined cutting position inside the steel pipe section 11 (see Figures 1 and 2).

[0038] As shown in Figure 9, when the cutting position is reached, the cutting device 20 is positioned. Specifically, the support frame 26 is extended to the required length using the support jack 33, and the contact portion 41 of the contact member 40 is brought into close contact with the inner circumferential surface 11a of the steel pipe section 11. This positions the cutting device 20 relative to the steel pipe section 11.

[0039] As shown in Figure 10, once positioning is complete, the cutting device 20 begins cutting. Specifically, the cutting frame 46 is extended to the cutting length using the cutting jack 50, and then the drive units 75 of the rotating mechanism 23 are driven to rotate the cutting mechanism 22. While the cutting mechanism 22 is still rotating, the cutting blade adjustment mechanism 58 is driven to gradually move the cutting blade 57 from the stored position to the maximum protruding position, as shown in Figures 6(b) and 6(c). At this time, the cutting blade 57 cuts into the steel pipe section 11 and protrudes to the maximum protruding position while scraping the steel pipe section 11. When the cutting blade 57 has moved to the maximum protruding position, the steel pipe section 11 is cut.

[0040] Once cutting is complete, the rotation mechanism 23 is stopped, and the cutting blade adjustment mechanism 58 moves the cutting blade 57 to its storage position. Then, the cutting frame 46 is retracted from the cutting length to the shortest length using the cutting jack 50, and then the support frame 26 is retracted from the pressing length to the shortest length using the support jack 33. This completes the cutting of the steel pipe section 11 by the cutting device 20.

[0041] After cutting, the cutting frame 46 is retracted from the cutting length to the shortest length using the cutting jack 50. The support frame 26 is then pressed against the frame at its original length, and the support mechanism 21 supports the cut and separated steel pipe section 11. The cut and separated steel pipe section 11 and the cutting device 20 may then be lifted up and collected.

[0042] Furthermore, the sequence of operations after reaching the cutting position may be performed based on the operator's actions using the operating device of the hydraulic supply unit 37. Alternatively, it may be performed automatically by a control device capable of controlling the hydraulic supply unit 37. In this case, cutting conditions such as the pressing length and cutting length are pre-programmed into the control device.

[0043] The effects of this embodiment will now be explained. (1) The cutting device 20 comprises a support mechanism 21 having a plurality of support frames 26 that can extend and retract in the radial direction of the steel pipe section 11, a cutting mechanism 22 having a plurality of cutting frames 46 configured to extend and retract in the radial direction of the steel pipe section 11 and having cutting blades 57 at their tips, a connecting part 24 that rotatably connects the center of the cutting mechanism 22 to the center of the support mechanism 21, and a rotation mechanism 23 that rotates the cutting mechanism 22 around the central axis of the steel pipe section 11 relative to the support mechanism 21.

[0044] In this cutting device 20, the tip of the support frame 26 can be pressed against the inner circumferential surface 11a of the steel pipe section 11, allowing the cutting device 20 to be positioned at a desired cutting position inside the steel pipe section 11. As a result, the degree of freedom in determining the cutting position of the steel pipe section 11 can be improved.

[0045] (2) The cutting device 20 includes a cutting blade adjustment mechanism 58 that moves the cutting blade 57 in the extension and retraction direction of the cutting frame 46 to adjust the amount of protrusion of the cutting blade 57 from the cutting frame 46. This allows the cutting frame 46 to be maintained at a predetermined cutting length while the amount of protrusion of the cutting blade 57 is adjusted to cut the steel pipe section 11 appropriately.

[0046] (3) The support mechanism 21 has a pressing member 40 at the tip of the support frame 26 that is pressed against the inner circumferential surface 11a of the steel pipe section 11, and the pressing member 40 is configured to be detachable. In other words, the support mechanism 21 is configured so that the pressing member 40 can be replaced to match the diameter of the steel pipe section 11. This allows the pressing member 40 to adhere more firmly to the inner circumferential surface 11a of the steel pipe section 11.

[0047] (4) The rotating mechanism 23 includes a driven gear 73 fixed to the cutting mechanism 22, a plurality of drive gears 74 that mesh with the driven gear 73, and a plurality of drive units 75 provided corresponding to each of the plurality of drive gears 74 and fixed to the support mechanism 21 to drive the corresponding drive gear 74. As a result, the cutting mechanism 22 can be rotated with greater force by using multiple drive units 75.

[0048] (5) Multiple drive gears 74 are arranged symmetrically with respect to the rotation axis 22A of the cutting mechanism 22. Multiple drive units 75 are also arranged symmetrically with respect to the rotation axis 22A of the cutting mechanism 22. This allows for a balanced weight distribution of the cutting device 20. As a result, the cutting device 20 becomes more stable when, for example, it is raised or lowered using a crane or the like.

[0049] (6) The cutting mechanism 22 has a link mechanism 65 that connects the tip ends of a pair of cutting frames 46 that are adjacent to each other in the rotational direction. The link mechanism 65 has an arc-shaped first link 66 whose base end is connected to one of the pair of cutting frames 46 so as to be rotatable about a rotation axis that extends in the vertical direction, and an arc-shaped second link 67 whose base end is connected to the other of the pair of cutting frames 46 so as to be rotatable about a rotation axis that extends in the vertical direction, and the tip end of the first link 66 and the tip end of the second link 67 are connected so as to be rotatable about a rotation axis that extends in the vertical direction. When the cutting frames 46 are at a cutting length that allows the steel pipe section 11 to be cut by the cutting blade 57, the first link 66 and the second link 67 are arranged to draw an arc along the steel pipe section 11.

[0050] This allows the resistance force acting on one cutting frame 46 when cutting the steel pipe section 11 to be effectively distributed to other cutting frames 46. In other words, the resistance force acting on one cutting frame 46 can be received by the entire cutting mechanism 22.

[0051] (7) The cutting mechanism 22 is located below the support mechanism 21. This allows the cutting device 20 to be supported by the cut portion of the steel pipe 11 when the steel pipe section 11 is being cut. As a result, the cut portion can be lifted by raising the cutting device 20 using a crane.

[0052] (8) The link mechanism 65 is configured such that the first link 66 and the second link 67 can be attached to and detached from the cutting mechanism 22. This allows the link mechanism 65 to be configured to match the diameter of the steel pipe section 11 to be cut.

[0053] Although one embodiment of the cutting device has been described above, the present invention is not limited to the above-described embodiment and can be modified as appropriate without departing from its spirit. For example, this embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict the technical aspects.

[0054] The cutting device 20 does not necessarily have to include a link mechanism 65 that connects a pair of adjacent cutting frames 46 around the rotation axis 22A of the cutting mechanism 22.

[0055] The rotating mechanism 23 is not limited to a configuration in which, when viewed from above, multiple drive units 75 are arranged symmetrically around the rotation axis 22A of the cutting mechanism 22. When viewed from above, the rotating mechanism 23 may have multiple drive units 75 provided at equal intervals around the rotation axis 22A of the cutting mechanism 22. This allows for a balance in the weight distribution of the cutting device 20 while increasing the degree of freedom regarding the number of drive gears 74 installed.

[0056] The rotating mechanism 23 is not limited to a configuration using a driven gear 73, a plurality of drive gears 74, and a plurality of drive units 75. The rotating mechanism 23 may also be configured such that, for example, the output shaft of the drive unit 75 is connected to the center of the cutting mechanism 22.

[0057] The support frame 26 may be configured such that the pressing member 40 is fixed to the outer support frame 32. In such a configuration, it is preferable to increase the thickness of the contact portion 41 made of an elastic material. Furthermore, it is not necessary to have an elastic contact portion 41. For example, the contact portion 41 may be made of a non-elastic material, or the pressing member 40 itself may be pressed against the steel pipe portion 11 without having a contact portion 41 as in this embodiment.

[0058] Each support jack 33 is configured to receive and discharge the same hydraulic pressure from the hydraulic supply unit 37. However, this is not the only option; for example, the hydraulic pressure for each support jack 33 may be monitored and controlled for each support jack 33. That is, the amount of expansion and contraction, the pressure applied to the inner circumferential surface 11a, etc., may be controlled for each support frame 26. With this configuration, the cutting device 20 can be supported even on steel pipe sections 11 that are not perfectly circular in shape.

[0059] Each cutting jack 50 is configured to receive and discharge the same hydraulic pressure from the hydraulic supply unit 37. However, the hydraulic pressure may be controlled for each cutting jack 50 by measuring the distance from the inner circumferential surface 11a of the steel pipe section 11 using, for example, an ultrasonic sensor. With this configuration, even if the steel pipe section 11 is not perfectly circular, each cutting frame 46 can be positioned at a predetermined distance from the inner circumferential surface 11a.

[0060] The cutting mechanism 22 includes a cutting blade adjustment mechanism 58 that adjusts the amount of protrusion of the cutting blade 57 from the cutting frame 46. In other words, the amount of protrusion of the cutting blade 57 is variable. However, the amount of protrusion of the cutting blade 57 from the cutting frame 46 may be constant. Even with this configuration, the steel pipe section 11 can be cut by extending the cutting frame 46 while rotating the cutting mechanism 22.

[0061] Each cutting blade adjustment mechanism 58 is configured to receive and discharge the same hydraulic pressure from the hydraulic supply unit 37. However, this is not limited to this configuration; for example, the hydraulic pressure for each cutting blade adjustment mechanism 58 may be monitored and controlled for each cutting blade adjustment mechanism 58. With such a configuration, the amount of protrusion of the cutting blade 57 can be controlled for each cutting frame 46.

[0062] The cutting device 20 may be configured such that the cutting mechanism 22 is positioned above the support mechanism 21.

[0063] Furthermore, although this embodiment describes the cutting device 20 as being used to cut the steel pipe section 11 of the pile (support column, monopile) used in offshore wind power generation equipment, the cutting device 20 may also be used to cut steel pipe sections 11 other than those used in offshore wind power generation equipment. [Explanation of Symbols]

[0064] 11...Steel pipe section, 11a...Inner circumferential surface, 20...Cutting device, 21...Support mechanism, 22...Cutting mechanism, 22A...Rotation axis, 23...Rotation mechanism, 24...Connecting section, 26...Support frame, 31...Inner support frame, 32...Outer support frame, 33...Support jack, 34...Support cylinder, 35...Support rod, 37...Hydraulic supply machine, 40...Pressing member, 41...Contact section, 41a...Contact surface, 46...Cutting frame, 47...Inner cutting frame, 48...Outer cutting 49...Cutting frame, 50...Frame body, 51...Cutting cylinder, 52...Cutting rod, 55...Link connecting member, 57...Cutting blade, 58...Cutting blade adjustment mechanism, 59...Cylinder for cutting blade, 60...Rod for cutting blade, 65...Link mechanism, 66...First link, 67...Second link, 68...First base rotating shaft, 69...Second base rotating shaft, 70...Tip rotating shaft, 73...Driven gear, 74...Drive gear, 75...Driver, 75A...Output shaft.

Claims

1. A support mechanism having multiple support frames that can expand and contract in the radial direction of the steel pipe section, A cutting mechanism comprising a plurality of cutting frames configured to be extendable and retractable in the radial direction of the steel pipe section and having cutting blades at their tips, A connecting portion that rotatably connects the center of the cutting mechanism to the center of the support mechanism, The support mechanism is further provided with a rotation mechanism that rotates the cutting mechanism around the central axis of the steel pipe section, The aforementioned cutting mechanism is The cutting mechanism has a link mechanism that connects the tip portions of a pair of cutting frames that are adjacent to each other in the rotational direction of the cutting mechanism, The aforementioned link mechanism is One of the pair of cutting frames is provided with an arc-shaped first link whose base end is rotatably connected to a rotation axis extending in the vertical direction, The other of the pair of cutting frames has an arc-shaped second link whose base end is rotatably connected to a rotation axis extending in the vertical direction, The tip of the first link and the tip of the second link are rotatably connected with respect to a rotation axis extending in the vertical direction. When the cutting frame is at a cutting length that allows the cutting blade to cut the steel pipe, the first link and the second link are arranged to form an arc along the steel pipe. Cutting device.

2. The aforementioned rotating mechanism is A driven gear fixed to the cutting mechanism, Multiple drive gears that mesh with the driven gear, The system includes a plurality of drive units provided corresponding to each of the plurality of drive gears, fixed to the support mechanism, and driving the corresponding drive gears. The cutting device according to claim 1.

3. A support mechanism that moves up and down inside a steel pipe section while suspended, the support mechanism having a plurality of support frames that can expand and contract by the same amount in the radial direction of the steel pipe section, A cutting mechanism located below the support mechanism, comprising a plurality of cutting frames configured to be extendable and retractable in the radial direction of the steel pipe section and having cutting blades at their tips, A connecting portion that rotatably connects the center of the cutting mechanism to the center of the support mechanism, the connecting portion having one end connected to the center of the cutting mechanism and the other end connected to the center of the support mechanism, The support mechanism is further provided with a rotation mechanism that rotates the cutting mechanism around the central axis of the steel pipe section, The aforementioned support frame is The steel pipe section has an inner support frame that extends radially and an outer support frame that is movable along the extending direction of the inner support frame, The aforementioned support mechanism is Each of the support frames is provided with a support jack that moves the outer support frame relative to the inner support frame, The aforementioned support jack is, A support cylinder fixed to the inner support frame and extending in the direction of extension of the inner support frame, It comprises a support rod that is configured to move back and forth in the extending direction of the support cylinder relative to the support cylinder and is fixed to the outer support frame, The aforementioned rotating mechanism is A driven gear fixed to the cutting mechanism, Multiple drive gears that mesh with the driven gear, The system includes a plurality of drive units provided corresponding to each of the plurality of drive gears, fixed to the support mechanism, and driving the corresponding drive gears. Cutting device.

4. The plurality of drive gears are arranged symmetrically around the rotation axis of the cutting mechanism. The aforementioned plurality of drive units are arranged symmetrically around the rotation axis of the cutting mechanism. The cutting apparatus according to claim 2 or 3.

5. The cutting blade adjustment mechanism moves the cutting blade in the extension and retraction direction of the cutting frame to adjust the amount the cutting blade protrudes from the cutting frame. A cutting device according to any one of claims 1 to 4.

6. The aforementioned support mechanism is The support frame has a pressing member at its tip that is pressed against the inner circumferential surface of the steel pipe section, and the pressing member is configured to be detachable. A cutting device according to any one of claims 1 to 5.

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