Cylindrical body polishing structure and cylindrical body polishing method

Abstract

To provide a cylindrical body polishing structure and a cylindrical body polishing method which prevent generation of polishing unevenness and can adequately shorten polishing time, in polishing of an inner peripheral surface of a large-sized cylindrical body.SOLUTION: A cylindrical body polishing structure (100) is a structure for polishing an inner peripheral surface (201) of a cylindrical body (200), and includes a first polishing device (10) which is arranged inside the cylindrical body (200) and has an injection part (11) capable of injecting an abrasive toward the inner peripheral surface (201) of the cylindrical body (200), a first moving mechanism for moving the first polishing device (10) in an elongation direction of the cylindrical body (200), and a rotation mechanism for rotating the cylindrical body (200) around an axis. A cylindrical body polishing method arranges a first polishing device (10) inside a cylindrical body (200) so as to be movable in an elongation direction of the cylindrical body (200) by a first moving mechanism, and polishes the inner peripheral surface (201) of the cylindrical body (200) by any one of a first embodiment to a third embodiment.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a polishing structure and a polishing method for polishing the peripheral surface of a cylindrical body, and more particularly to a polishing structure and a polishing method for polishing at least the inner peripheral surface of a large-diameter cylindrical body. [Background technology]

[0002] In recent years, interest in global environmental issues has been growing worldwide. In the field of energy technology, technologies related to the utilization of natural energy have been promoted in light of issues such as global warming. With regard to the utilization of natural energy, expectations are rising for the development and implementation of wind power generation equipment, for example.

[0003] In wind turbines, the blades are subjected to intermittent wind force, making the tower that supports them crucial. Towers are typically constructed as cylindrical bodies made of metal such as iron. The towers of onshore wind turbines are exposed to wind and rain at the top and seawater at the bottom. To prevent the tower from rusting or breaking under these harsh operating conditions, the outer surface of the tower must be thoroughly polished and then painted.

[0004] Conventionally, polishing of the inner surface of a large-diameter cylindrical body, such as that used in the tower of a wind power generation device, has typically been carried out by a worker wearing a dust mask or the like entering the inside of the cylindrical body and using a handheld polishing device (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-62022 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when polishing the inner peripheral surface of a large cylindrical body using a handheld polishing device, the following problems arise. That is, when the curved, large-area inner peripheral surface is polished by an operator's intuition, uneven polishing may occur depending on the operator's level of skill. On the other hand, if the work is done carefully to prevent uneven polishing, the polishing time will be longer and there is a risk that an amount of abrasive significantly exceeding the necessary and sufficient amount will be projected onto the surface to be polished. It is also known that immediately after polishing, cylindrical objects made of metals such as iron begin to oxidize and become contaminated with dust and other contaminants (hereinafter referred to as "oxidation of the polished surface"). As oxidation of the polished surface progresses, the coating film formed in the subsequent painting process becomes more likely to peel off. Therefore, it is generally necessary to subject the polished cylindrical object to the painting process within a predetermined time (for example, about 6 hours) after the start of polishing. Therefore, it is desirable to shorten the polishing time appropriately.

[0007] The present invention has been made in view of the above-mentioned problems. That is, the present invention relates to polishing the inner peripheral surface of a large cylindrical body, and provides a cylindrical body polishing structure and a cylindrical body polishing method that can prevent the occurrence of polishing unevenness and appropriately shorten the polishing time. [Means for solving the problem]

[0008] The cylindrical body polishing structure of the present invention is a cylindrical body polishing structure for polishing the inner peripheral surface of a cylindrical body, and includes a first polishing device that is arranged inside the cylindrical body and has an injection part that can inject an abrasive toward the inner peripheral surface of the cylindrical body, a first moving mechanism that moves the first polishing device in the extension direction of the cylindrical body, and a rotation mechanism that rotates the cylindrical body around its axis. The first moving mechanism includes a first guide portion that is inserted into the cylindrical body and extends in the extension direction of the cylindrical body, and a first moving portion that supports the first grinding device and is movable along the first guide portion, the first guide portion having a rail that extends in the extension direction of the cylindrical body and a caster that is provided on the underside of the rail and is capable of abutting on the inner peripheral surface, and the axial direction of the rotation axis of the caster is the same as the extension direction of the cylindrical body. It is characterized by the following.

[0009] The cylindrical body polishing method of the present invention is a cylindrical body polishing method for polishing the inner surface of a cylindrical body using the cylindrical body polishing structure of the present invention, characterized in that the first polishing device is arranged inside the cylindrical body so that it can be moved in the extension direction of the cylindrical body by the first moving mechanism, and the inner surface of the cylindrical body is polished by any of the following first to third aspects. The first aspect is an aspect in which a first step of fixing the cylindrical body and moving the first grinding device by the first moving mechanism to grind the inner circumferential surface in a band-like manner in the extension direction of the cylindrical body, and a second step of stopping the movement of the first grinding device and rotating the cylindrical body by a predetermined angle around its axis after the first grinding device arrives at a predetermined position in the extension direction of the cylindrical body, is repeated; the second aspect is an aspect in which a first step of fixing the position of the first grinding device and rotating the cylindrical body around its axis to grind the inner circumferential surface in a circumferential direction, and a second step of stopping the rotation of the cylindrical body and moving the first grinding device by the first moving mechanism by a predetermined distance in the extension direction of the cylindrical body after the inner circumferential surface of the cylindrical body has been ground in the circumferential direction over a predetermined width in the extension direction of the cylindrical body by the first step, is repeated; and the third aspect is an aspect in which the first grinding device is moved by the first moving mechanism and the cylindrical body is rotated around its axis to grind the inner circumferential surface of the cylindrical body in a spiral manner. [Effects of the Invention]

[0010] The cylindrical body polishing structure and cylindrical body polishing method of the present invention, which have the above-mentioned configuration, make it possible to polish the inner surface of a large cylindrical body without relying on the worker's sense, thereby preventing uneven polishing and making it possible to appropriately shorten the polishing time. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view of a cylindrical body polishing structure according to a first embodiment of the present invention, observed from the axial direction of the cylindrical body. FIG. [Figure 2] 1 is a side view of a cylindrical body polishing structure according to a first embodiment of the present invention, observed from a direction perpendicular to the cylindrical body axial direction. FIG. [Figure 3]FIG. 2 is a partial side view of a modified example of the cylindrical body polishing structure according to the first embodiment of the present invention. [Figure 4] FIG. 10 is a side view of a cylindrical body polishing structure according to a second embodiment of the present invention, observed from the axial direction of the cylindrical body. [Figure 5] FIG. 10 is a conceptual diagram for explaining a cylindrical body polishing method according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a conceptual diagram for explaining a cylindrical body polishing method according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by the same reference numerals, and duplicated descriptions will be omitted where appropriate. The various components of the present invention do not need to be independent entities, and it is acceptable for multiple components to be formed as a single member, for one component to be formed from multiple members, for one component to be part of another component, or for part of one component to overlap with part of another component, etc.

[0013] First Embodiment A cylindrical body polishing structure 100 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. A cylindrical body polishing structure 110 according to a modified example of this embodiment will be described with reference to FIG. 3. FIG. 1 is a side view of the cylindrical body polishing structure 100 according to the first embodiment of the present invention, observed from the axial direction of the cylindrical body 200. FIG. 2 is a side view of the cylindrical body polishing structure 100 observed from a direction perpendicular to the axial direction of the cylindrical body 200. FIG. 2 shows a side view of the interior of the cylindrical body 200 with the front half of the cylindrical body 200 removed. FIG. 3 is a partial side view of a cylindrical body polishing structure 110, a modified example of the cylindrical body polishing structure 100.

[0014] As shown in FIGS. 1 and 2 , the cylindrical body polishing structure 100 according to this embodiment is a structure for polishing the inner surface 201 of a cylindrical body 200. The cylindrical body 200 is a cylindrical structure with both ends open and made of a metal member such as iron. Examples of the cylindrical body 200 include, but are not limited to, wind power generation towers and large pipelines for gas and oil. In this embodiment, the cylindrical body 200 is described as a tubular body with a substantially uniform circular cross section. However, the object to be polished in the present invention is not limited to this and may be, for example, a cylindrical body with a polygonal cross section or a cone (more specifically, a cone or a square pyramid) whose cross section tapers toward its tip. When the cylindrical body is a cone, as in FIG. 2 , a turning roll 31 of the same height may be installed in a linear direction, and the cone may be placed on the turning roll 31 so that the lower end of the lying cone is horizontal. Then, inside the cone, the polishing device can be moved from one end of the cone to the other while adjusting the distance from the injection section 12 to the inner surface of the cone and the distance between the tip of the hopper 40 and the inner surface of the cone.

[0015] The size of the cylindrical body 200 is not particularly limited. However, for example, the cylindrical body polishing structure 100 can effectively polish a cylindrical body 200 having an inner diameter of 150 cm or more or 200 cm or more. In particular, as shown in FIG. 2, the present invention is suitable for polishing a large-diameter cylindrical body 200 that allows an adult male worker 203 to stand and work inside the pipe. Therefore, the present invention is suitable for polishing large-diameter cylindrical bodies used, for example, in the towers of wind power generation equipment. Furthermore, when the cylindrical body 200 is a cylindrical body with a polygonal cross section, the cylindrical body polishing structure 100 can effectively polish a cylindrical body 200 having a long side length of 150 cm or more or 200 cm or more. Furthermore, when the cylindrical body 200 is a cone, the cylindrical body polishing structure 100 preferably has an inner diameter at the tapered tip opening within the above-mentioned range.

[0016] The cylindrical body polishing structure 100 includes a first polishing device 10, a first moving mechanism 20, and a rotation mechanism 30. The first polishing device 10 is a polishing device that is disposed inside a cylindrical body 200 and has an injection unit 11 that is capable of injecting an abrasive toward an inner peripheral surface 201 of the cylindrical body 200. The first moving mechanism 20 is a mechanism for moving the first polishing device 10 in the extension direction of the cylindrical body 200. The rotation mechanism 30 is a mechanism for rotating the cylindrical body 200 around its axis. In the present invention, when the cylindrical body that is the object to be polished is a tubular body as shown in Figure 1 etc., the "extension direction of the cylindrical body" refers to the axial direction of the cylindrical body. On the other hand, when the cylindrical body is a cone and the present invention is implemented by placing the cone so that its lower end is horizontal, the "axial direction of the cylindrical body" can be appropriately interpreted as the "extension direction of the lower end of the horizontally lying cone." Below, with regard to the cylindrical body 200 that is an annular body, an embodiment will be described in which the extension direction of the cylindrical body 200 is the axial direction of the cylindrical body 200.

[0017] The cylindrical body polishing structure 100 having such a configuration allows the first polishing device 10 to be moved in the axial direction of the cylindrical body 200 while rotating the cylindrical body 200 about its axis. This configuration eliminates the need for an operator to perform the polishing work using a portable polishing device, as in the past, and allows for uniform mechanical polishing of the inner peripheral surface 201. Furthermore, the cylindrical body polishing structure 100 can adjust the polishing time by adjusting the amount of projection per unit time of the first polishing device 10, the timing and speed of its movement, and the timing and speed of the rotation of the cylindrical body 200. Therefore, the time required to supply the polished cylindrical body 200 to the next process (e.g., a painting process) can be shortened and accurately controlled. The cylindrical body polishing structure 100 will be described in more detail below.

[0018] [First movement mechanism] In this embodiment, the first moving mechanism 20 comprises a first guide portion (rail 21) that is inserted into the interior of the cylindrical body 200 and extends in the axial direction of the cylindrical body 200, and a first moving portion (wheel 22) that supports the first grinding device 10 and is movable along the first guide portion. By using such a mechanism, the first grinding device 10 equipped with the first moving part can be moved along the first guide part in the axial direction of the cylindrical body 20. Therefore, there is no need for an operator to carry a portable grinding device during work.

[0019] Rail 21, which is the first guide portion, is inserted into inner peripheral surface 201 of cylindrical body 200 without contacting it. Both ends of rail 21 protruding to the outside from both end openings of cylindrical body 200 are supported by rail bases 81 provided outside cylindrical body 200. Thus, rail 21, which is the first guide portion, has a simple structure and can be easily installed and removed from cylindrical body 200.

[0020] In this embodiment, a caster 23 capable of abutting against the inner peripheral surface 201 is provided on the underside of the rail 21 in the middle portion so that the rail 21 can sufficiently withstand the weight of the first polishing apparatus 10. The axial direction of the rotation axis of the caster 23 is the same as the axial direction of the cylindrical body 200. Therefore, the caster 23 can support the middle portion of the rail 21 without interfering with the rotation of the cylindrical body 200 about its axis. Although the embodiment illustrates an embodiment having one caster 23, two or more casters 23 may be provided, and the caster 23 may be omitted if the cylindrical body 200 is short or if the strength of the rail 21 is sufficient.

[0021] Although not shown, the present invention includes a first guide section in an embodiment in which the rail base 81 is omitted and two or more casters 23 are provided. In such an embodiment, the rail 21 is supported by the plurality of casters 23 that abut against the inner peripheral surface 201. As described above, the axial direction of the rotation axis of the caster 23 is the same as the axial direction of the cylindrical body 200, and therefore, each of the plurality of casters 23 allows rotation of the cylindrical body 200 around its axis while supporting the rail 21.

[0022] A first moving part is provided directly or indirectly on the first grinding apparatus 10 as a guided member guided by the rail 21, which is the first guide part. The first moving part supports the first grinding apparatus 10 and is movable along the first guide part described above. This allows the first grinding apparatus 10 to move along the first guide part.

[0023] In this embodiment, wheels 22 are provided on the first grinding apparatus 10 as the first moving part. The wheels 22 are rotating bodies provided directly or indirectly on the underside of the first grinding apparatus 10, and the axial direction of the rotation axis thereof is perpendicular to the axial direction of the cylindrical body 200. In this embodiment, the wheels 22 are fitted into wheel fitting portions 24 provided on the rail 21. The wheel fitting portions 24 are continuous grooves formed on the upper surface side of the rail 21 along the axial direction of the cylindrical body 200. By fitting the wheels 22 into the grooves, the wheels 22 are guided in the axial direction of the cylindrical body 200.

[0024] In this embodiment, the wheels 22 are formed to be rotatable when external stress is applied to the first grinding apparatus 10. Therefore, with the first grinding apparatus 10 equipped with the wheels 22 installed on the rails 21, the first grinding apparatus 10 can be moved by an operator 203 pushing the first grinding apparatus 10 as shown in Fig. 2. However, the present invention also encompasses an embodiment in which a drive unit for driving the wheels 22 by electricity or the like is provided and the first grinding apparatus 10 is moved unmanned inside the cylindrical body 200. Furthermore, in order to more accurately control the movement of the first polishing apparatus 10, the first moving unit may further be provided with a control unit for controlling the rotation speed of the wheels 22, the start of movement, the stop of movement, etc. The control unit may be remotely operable, so that the inside of the cylindrical body 200 is substantially unmanned, or a control panel may be provided directly or indirectly on the first polishing apparatus 10, and the movement of the first polishing apparatus 10 may be controlled by the operator 203 directly operating the control panel.

[0025] [First polishing device] Next, the first grinding apparatus 10 will be described. As described above, the first grinding apparatus 10 is provided with wheels 22 directly or indirectly. In this embodiment, the first grinding apparatus 10 is placed on a transport device (low-lift truck 84) equipped with a table 27 that can move in the vertical direction. The wheels 22 attached to the low-lift truck 84 allow the first grinding apparatus 10 to move along rails 21 inside the cylindrical body 200. In other words, this embodiment shows an example in which the wheels 22 are indirectly provided on the first grinding apparatus 10.

[0026] The low lift truck 84 comprises an operating unit 86 that enables a worker 203 to directly or indirectly operate the low lift truck 84, a table 27, a platform 26 provided on the underside of the table 27, a wheel mounting part 25 provided on the underside of the platform 26, and wheels 22 attached to the wheel mounting part 25. A height adjustment mechanism 28 for adjusting the height of the table 27 is provided between the platform 26 and the table 27, thereby making it possible to change the height position of the table 27.

[0027] A dust collector 83 is provided on the stand 26 alongside the first polishing apparatus 10. One end of a duct (not shown) is disposed inside the hopper 40, and the other end is connected to the dust collector 83. Dust generated inside the hopper 40 by polishing is collected by the dust collector 83.

[0028] In this embodiment, the first polishing device 10 is installed on the upper surface of the table 27 and disposed inside the cylindrical body 200. The first polishing device 10 has an injection unit 11 capable of injecting an abrasive toward the inner circumferential surface 201 of the cylindrical body 200. In this embodiment, the injection unit 11 has an elongated injection opening that is long in one direction. Specifically, as can be seen from FIGS. 1 and 2 , the injection opening of the injection unit 11 is narrow in the horizontal and perpendicular directions to the axial direction of the cylindrical body 200 as shown in FIG. 1 , and is an elongated opening in the axial direction of the cylindrical body 200 as shown in FIG. 2 . As shown in FIG. 2 , the abrasive repelled by the rotor 12 is injected from this elongated injection opening over a wide area, not just vertically upward. The injection direction of the injection unit 11 can be adjusted by the installation angle of the first polishing device 10 inside the cylindrical body 200 and is not limited to the direction shown in FIGS. 1 and 2 . Furthermore, the injection opening of the injection unit in the present invention is not limited to the form of the injection opening of injection unit 11 shown in Figures 1 and 2. For example, in the present invention, the injection opening for injecting the abrasive may extend in a direction that is neither perpendicular nor horizontal to the axial direction of cylindrical body 200, or the opening surface may be angled, taking into consideration the diameter of cylindrical body 200, the distance to the arc portion, and the like. The first polishing device 10 is a so-called blasting device. It is particularly preferred that the first polishing device 10 be a centrifugal blasting device equipped with a rotor 12 rotated by a motor 13. Conventionally, handheld polishing devices used to polish the inner circumferential surface of a cylindrical body have generally been direct-pressure air blasting devices using a compressor. However, a direct-pressure air blasting device has the problem of requiring a large amount of electricity to polish a large area. In contrast, a centrifugal blasting device using a motor 13 and rotor 12 can reduce the amount of electricity and shorten the polishing time compared to polishing the same area using the air blasting device, making it preferable from the standpoint of both cost and energy savings.

[0029] The type of abrasive used in the first polishing device 10 and the structure of the injection unit 11 are not particularly limited. Examples of abrasives include iron abrasives such as steel shot and steel grit, stainless steel abrasives, alumina abrasives, and sand. Iron abrasives are preferred because they are less likely to break upon impact with the surface to be polished and are suitable for reuse. Furthermore, when the object to be polished is made of a material other than iron (especially stainless steel), it is preferable to use a non-iron abrasive to prevent the occurrence of so-called transfer rust on the polishing surface. The injection unit 11 is provided facing a rotor 12 equipped with a plurality of rotating blades (not shown), and the abrasive is injected from the injection unit 11 by the rotational force of the rotating blades. The rotor 12 is driven to rotate by a motor 13 provided therewith, and the injection distance of the abrasive can be increased by increasing the rotation speed. Therefore, it is also possible to change the distance between the injection unit 11 and the inner peripheral surface 201 by changing the number of rotations per unit time (rotational speed) of the rotor 12. Such a so-called rotor-type shot blasting device is a preferred example of the first polishing device 10.

[0030] The first polishing apparatus 10 is attached and fixed to a cabinet 14 that supports it. In this embodiment, the cabinet 14 is a substantially rectangular box-shaped body. The cabinet 14 is installed on a table 27, which allows the first polishing apparatus 10 to be placed on a low-lift truck 84. Therefore, the height of the table 27 can be adjusted using a height adjustment mechanism 28 of the low-lift truck 84 to adjust the height of the first polishing apparatus 10. By using the height adjustment mechanism 28 in this way, the distance from the injection port 11 to the inner circumferential surface 201 can be adjusted, making it easy to adapt the first polishing apparatus 10 to various cylindrical bodies with different inner diameters. 1, in order to maintain the cabinet 14 supporting the first polishing apparatus 10 in a stable installation state on the table 27, horizontally extendable arms 15 are provided on each of the two opposing lateral sides of the cabinet 14, and casters 16 are provided at the ends of the arms 15. When viewed in the axial direction of the cylindrical body 200, the pair of left and right casters 16 abut against the inner peripheral surface 201, thereby effectively preventing horizontal shaking of the cabinet 14 and the first polishing apparatus 10 supported thereby. Furthermore, a pair of casters 29, one on each side when viewed in the axial direction of the cylindrical body 200, is provided on the underside of the platform 26. The casters 29 abut against the inner peripheral surface 201 of the cylindrical body 200, thereby preventing the low lift truck 84 from shaking. The casters 16 and 29 described above have rotation axes that extend in the same direction as the axial direction of the cylindrical body 200. Therefore, the casters 16 and 29 can prevent the low lift truck 84 and the first polishing device 10 installed thereon from shaking inside the cylindrical body 200 without interfering with the rotation of the cylindrical body 200 about its axis.

[0031] The cabinet 14 is provided with a tank 44 for storing abrasives. One end of a feed pipe 43, which is a cylinder with open ends and through which the abrasives can move, is connected to the tank 44. The other end of the feed pipe 43 is connected to the rotor 12, thereby connecting the tank 44 and the rotor 12. The abrasives filled in the tank 44 generally pass through the feed pipe 43 by their own weight and reach the rotor 12, or reach an open / close shutter (not shown) attached to the feed pipe 43. If a shutter is present, the shutter is opened to allow the abrasives to reach the rotor 12, and the abrasives are then ejected by rotating the rotating blades attached to the rotor 12. In this state, the abrasives stored in the tank 44 fall by their own weight to the rotor 12, where they are repelled one after another by the rotating blades and ejected from the ejection section 11, where they collide with the inner circumferential surface 201. A control panel 82 having switches and the like for operating the rotor 12 (for example, a switch for turning the rotation of the rotor 12 on and off, an emergency stop button, an adjustment unit for the rotation speed of the rotor 12, etc.) is installed on the outer circumferential surface of the cabinet 14. The control panel 82 may be operated directly by an operator 203, or may be remotely operated wirelessly.

[0032] In the first polishing mechanism 100, the projection amount, projection density, and projection speed of the abrasive are not particularly limited. For example, the projection amount is 40 kg / min to 300 kg / min, and the projection density is 70 kg / m 2 More than 90kg / m 2 Hereinafter, the projection speed can be adjusted within a range of 40 m / sec or more and 60 m / sec or less. The projection amount, projection density, and projection speed described above are appropriately adjusted depending on the inner diameter dimension of the cylindrical body 200 and the distance from the tip of the injection part 11 to the inner peripheral surface 201. These adjustments can also be made by adjusting the rotation speed of the rotor, the inner diameter of the feed pipe, the size of the injection opening of the injection part 11, etc.

[0033] After contacting the inner circumferential surface 201, the abrasive injected from the injection unit 11 spreads in all directions and falls under its own weight. The injected abrasive can be collected at an appropriate time, such as after polishing is completed. However, this requires either a larger tank 44 for storing the abrasive or frequent replenishment of new abrasive during polishing. In contrast, this embodiment includes a hopper 40 that covers the injection unit 11 of the first polishing device 10 and the projection area where the abrasive injected from the injection unit 11 can contact the inner circumferential surface 201. The hopper 40 prevents or suppresses the abrasive injected from the injection unit 11 from spilling outside the hopper 40. The base end of the hopper 40 (on the first polishing device 10 side) abuts tightly against the vicinity of the injection unit 11 so as to enclose the injection unit 11. Part or all of the base end of the hopper 40 may abut against the cabinet 14 supporting the first polishing device 10. Hopper 40 extends from the base end toward inner circumferential surface 201, and its tip (on the inner circumferential surface 201 side) is in contact with or close to inner circumferential surface 201 so as to encompass the projection area. Hopper 40 is also provided with an abrasive recovery section 42 that is continuous with it. Abrasive recovery section 42 and hopper 40 are connected via an opening 45 (see FIG. 1 ) located below the midpoint of hopper 40 in the height direction. Hopper 40 is connected to opening 45 located below hopper 40 so as to slope downward, and abrasive that comes into contact with inner circumferential surface 201 is configured to collect in opening 45 by its own weight. With this configuration, abrasive that is injected from injection section 11 and hits inner circumferential surface 201 and scatters in all directions falls by its own weight upon contact with hopper 40, and is collected in abrasive recovery section 42 via opening 45. In order to sufficiently recover the ejected abrasive material, the opening 45 is preferably provided at the lowest position of the hopper 40 .

[0034] The abrasive recovery section 42 is a space having a predetermined volume for storing or passing the recovered abrasive. In this embodiment, the abrasive recovery section 42 also serves as a tank 44 for storing the abrasive. As described above, the abrasive recovery section 42 (tank 44) and the rotor 12 are connected by the feed pipe 43, and the abrasive recovered and stored in the abrasive recovery section 42 is drawn into the rotor 12 as the rotor 12 rotates, and is reused for polishing.

[0035] The first polishing structure 100 of this embodiment, equipped with the hopper 40 described above, eliminates the time and effort required to recover abrasives after polishing, allowing the polished cylindrical body 200 to be quickly sent to the next process (e.g., a painting process). Furthermore, the abrasives recovered from the hopper 40 in the abrasive recovery section 42 can be returned to the rotor 12 via the feed pipe 43 and reused for polishing. This allows for a smaller tank 44, eliminates the need for new abrasives during polishing, or reduces the frequency of replenishment. Furthermore, the provision of the hopper 40 prevents the worker 203 working inside the cylindrical body 200 from inhaling the abrasives ejected from the cylindrical body 200, thereby alleviating health hazards, even when the first polishing device 10, mounted directly or indirectly on the rail 21, is manually pushed as shown in FIG. 2 .

[0036] From the viewpoints of preventing the injected abrasive from being released outside the hopper 40 and enabling good application to cylindrical bodies with different inner diameters, it is preferable to provide an elastic wall portion 41 made of an elastic material at the end (tip) of the hopper 40 on the inner circumferential surface 201 side, which is capable of abutting or coming close to the inner circumferential surface 201. It is more preferable that the elastic wall portion 41 be provided around the entire circumference of the tip of the hopper 40. Here, the end (tip) on the inner circumferential surface 201 side refers to a predetermined region of the hopper 40 on the inner circumferential surface 201 side, including the tip. In this embodiment, the elastic wall portion 41 abuts against the inner circumferential surface 201 so that no gap is generated between the elastic wall portion 41 and the inner circumferential surface 201. However, even if a predetermined gap is formed between the elastic wall portion 41 and the inner circumferential surface 201, sufficient abrasive recovery can be performed.

[0037] In the present invention, the elastic member may be any elastically deformable material, such as a mass of elastic material (elastic material) such as rubber or elastomer, or an aggregate of any material, such as a brush (fiber bundle) made of densely packed synthetic fibers. In this embodiment, a sheet-like elastic member made of rubber and having a thickness of approximately 2 mm to 10 mm is provided at the tip of the hopper 40. If the thickness of the elastic wall portion 41 made of an elastic material such as rubber is less than 2 mm, the elastic wall portion 41 may be too weak and may not function properly. On the other hand, if the thickness exceeds 10 mm, it may be difficult for the elastic wall portion 41 to smoothly follow the protrusions formed on the inner circumferential surface 201 of the cylindrical body 200. The elastic wall portion 41 made of an elastic material may be a single-layer sheet or a laminate of multiple sheets. If the elastic wall portion 41 is a laminate, the thickness of the laminate refers to the thickness of the laminate.

[0038] From the viewpoint of better adaptability to cylindrical bodies of different diameters, it is preferable that the mounting position of the elastic wall portion 41 be adjustable between the base end and the tip end of the hopper 40. Furthermore, the tower (cylindrical body) of a wind power generation device generally has protrusions such as various welded structures on the inner peripheral surface 201. When grinding the cylindrical body 200 having such protrusions, the attachment position of the elastic wall portion 41 may be adjusted so that a predetermined gap is left between the tip of the hopper 40 and the inner peripheral surface 201 in order to avoid collision with the tip of the hopper 40 or to reduce the area of ​​collision.

[0039] When polishing the cylindrical body 200 having the above-described convex portions on the inner peripheral surface 201, it is preferable to provide the elastic wall portion 41 from the viewpoint of preventing damage to the tip of the hopper 40 due to collision between the tip and the convex portions. Furthermore, in the event that the tip of the hopper 40 is damaged by collision with the convex portions, it is preferable to provide the tip of the hopper 40 detachably with respect to the main body of the hopper 40 so that the hopper 40 can be partially replaced rather than the entire hopper 40. Specifically, for example, it is preferable that the elastic wall portion 41 be detachably provided at the end of the hopper 40 on the inner peripheral surface 201 side.

[0040] [Rotation mechanism] Next, the rotation mechanism 30 for rotating the cylindrical body 200 about its axis will be described. The cylindrical body polishing structure 100 can move the first polishing device 10 inside the cylindrical body 200 in the axial direction of the cylindrical body 200 by the above-mentioned first moving mechanism 20, and can rotate the cylindrical body 200 about its axis by the rotation mechanism 30. This makes it possible to efficiently mechanically polish the inner surface 201 of the cylindrical body 200. The rotation mechanism 30 may be any mechanism that rotates the cylindrical body 200 about its axis. For example, in this embodiment, the rotation mechanism 30 is configured by a pair of turning rolls 31, 31 whose rotation axes are oriented in the same direction as the axial direction of the cylindrical body 200. Each turning roll 31 is configured to be rotatable about its axis by, for example, a driving unit (not shown). It is preferable that the turning roll 31 be controllable so that it can start and stop rotation at a desired timing and rotation speed.

[0041] The turning roll 31 described above is supported by a turning roll base 32. As shown in FIG. 1, the cylindrical body 200 is placed on a pair of turning rolls 31, 31 arranged at a predetermined distance and stably supported at a height that does not contact the floor surface. The turning rolls 31, 31 are rotated in the same direction, thereby rotating the cylindrical body 200 around its axis. As will be described later with reference to FIG. 4, a cylindrical body 200' having a different outer shape from the cylindrical body 200 can be placed on the pair of turning rolls 31, 31 arranged at a predetermined distance. However, if the distance between the pair of turning rolls 31, 31 is fixed, it may not be possible to accommodate other cylindrical bodies having outer diameters significantly different from the outer diameter of the cylindrical body 200. Therefore, it is preferable that the distance between the pair of turning rolls 31, 31 be adjustable, thereby enabling support of other cylindrical bodies having different outer diameters. In this embodiment, as shown in FIG. 2, at least two pairs of turning rolls 31, 31 are provided in the axial direction.

[0042] (Modification of the first embodiment) The first embodiment described above shows an example in which the abrasive collected in the abrasive collecting section 42 provided in the hopper 40 passes through the feed pipe 43 and is directly supplied to the rotor 12 by its own weight and the rotation of the rotor 12. However, the present invention is not limited to this, and includes a cylindrical body polishing mechanism 110 which is a modified example in which the abrasive collected in the abrasive collecting section 42 is transported by a transport section and then supplied to the rotor 12. Specifically, as shown in Fig. 3, the cylindrical body polishing mechanism 110 includes a screw conveyor 60 and a transfer elevator 61 as a transport section for the recovered abrasives. In this cylindrical body polishing mechanism 110, the abrasives recovered in the abrasive recovery section 42 are transported horizontally by the screw conveyor 60 to a predetermined position, and then transported upward by the transfer elevator 61 to be stored in a tank 44 provided separately from the abrasive recovery section 42. An openable lid 63 is provided above the tank 44, and abrasives can be filled into the tank 44 in advance through this lid, and abrasives can also be replenished as needed during polishing. The abrasive stored in the tank 44 is supplied to the rotor 12 through the feed pipe 43 by its own weight and the rotational force of the rotor 12. Examples of the transport elevator 61 include a bucket elevator equipped with multiple buckets that can move up and down, and a belt conveyor that can transport the abrasive diagonally upward. The cylindrical body polishing mechanism 110 is an example of the present invention that is equipped with a transport unit, and the structure of the transport unit is not limited to the above.

[0043] The cylindrical body polishing mechanism 110 is provided with a dust collection connection flange 62 between the lid 63 and the tank 44, and is connected to a dust collector (not shown) by a piping pipe or the like. This collects dust that rises in the transfer section, preventing dust explosions and dust leakage to the outside of the device.

[0044] As described above, the abrasive recovered from the hopper 40 to the abrasive recovery section 42 is reused by being returned directly or indirectly to the rotor 12. Whether the recovered abrasive is returned directly to the rotor 12 or returned to the rotor 12 after being transported by a transport section can be determined as appropriate in accordance with the inner diameter of the cylindrical body 200 and the shapes and dimensions of the first polishing device 10 and cabinet 14.

[0045] In the first embodiment described above, an example was shown in which the wheels 22, height adjustment mechanism 28, etc. were indirectly provided on the first sanding apparatus 10 by placing the first sanding apparatus 10 on the low-lift truck 84. However, the present invention is not limited to this, and includes, for example, an embodiment in which the wheels 22 and height adjustment mechanism 28 are directly provided on the first sanding apparatus 10 or the cabinet 14 that supports it. In other words, the first sanding apparatus in the present invention may be an apparatus that integrally includes various functions provided on the low-lift truck 84.

[0046] Second Embodiment Next, a cylindrical body polishing structure 120 according to a second embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a side view of the cylindrical body polishing structure 120 according to the second embodiment of the present invention, observed from the axial direction of the cylindrical body 200. In Fig. 4, the first moving mechanism 20 and the first polishing device 10 installed inside the cylindrical body 200 are not shown, and Figs. 1 and 2 are referred to as appropriate for the structures of these. The second embodiment is an embodiment in which, in addition to the cylindrical body polishing structure 100 of the first embodiment, a polishing device is also installed outside the cylindrical body 200.

[0047] Similar to the cylindrical body polishing structure 100, the cylindrical body polishing structure 120 includes a first polishing device 10 and a first moving mechanism 20 inside the cylindrical body 200, as well as a rotation mechanism 30 for rotating the cylindrical body 200 about its axis. For these components, please refer to the description of the cylindrical body polishing structure 100 and Figures 1 and 2. The cylindrical body polishing structure 120 further includes a second polishing device 50 installed on the outside of the cylindrical body 200 and having an injection unit 51 capable of injecting an abrasive toward the outer peripheral surface 202 of the cylindrical body 200, and a second moving mechanism 80 for moving the second polishing device 50 in the axial direction of the cylindrical body 200 along the outer peripheral surface 202 of the cylindrical body 200. The cylindrical body polishing structure 120 having such a configuration can polish not only the inner peripheral surface 201 but also the outer peripheral surface 202. In the cylindrical body polishing structure 120, the operation timing of the first polishing device 10 and the second polishing device 50 is not particularly limited, but by injecting abrasives from the first polishing device 10 and the second polishing device 50 at the same time, the inner peripheral surface 201 and the outer peripheral surface 202 of the cylindrical body 200 can be polished simultaneously. Here, "operation timing is the same" includes not only the case where the timings at which the first polishing device 10 and the second polishing device 50 inject abrasives are completely the same, but also the case where the injection times of both devices partially overlap.

[0048] [Second movement mechanism] In this embodiment, the second moving mechanism 80 includes a second moving part (wheels 57) that supports and is movable with the second grinding apparatus 50. The wheels 57, which are the second moving part, are rotating bodies that are provided directly or indirectly on the underside of the second grinding apparatus 50, and are arranged so that the axial direction of the rotation axis thereof is perpendicular to the axial direction of the cylindrical body 200. The second grinding device 50 is equipped with a hopper 55, which will be described later. Similar to the hopper 40 described above, the hopper 55 is a structure for preventing the abrasive material ejected from the second grinding device 50 from scattering in all directions. Therefore, the second grinding device 50 moves by means of wheels 57 while the tip of the hopper 55 (the end on the outer peripheral surface 202 side) is in contact with or close to the outer peripheral surface 202. In this manner of use, the hopper 55 can also serve as a spacer that maintains a constant distance between the second grinding device 50 and the cylindrical body 200. The second moving mechanism 80 can guide the second grinding device 50 to move in the axial direction of the cylindrical body 200 by means of the wheels 57 and the tip of the hopper 55 in contact with or close to the outer peripheral surface 202. For example, a sensor may be provided at the tip, and the wheels 57 may be rotated electrically to move the second polishing device 50 while controlling the tip to maintain a state in which the tip is in contact with the outer peripheral surface 202. In another embodiment, an operator (not shown) located outside the cylindrical body 200 may manually rotate the wheels 57 to move the second polishing device 50 while visually or otherwise checking that the tip is in contact with or close to the outer peripheral surface 202.

[0049] As described above, in an embodiment in which the wheels 57 rotate directly on the installation surface of the device without providing rails or the like in the second movement mechanism, it is preferable that the wheels 57 be made of an elastic material such as rubber. On the other hand, in an embodiment in which a second guide portion (for example, a rail) is provided and the wheels 57 rotate on the second guide portion as will be described later, it is preferable that the wheels 57 be made of a material harder than rubber (for example, metal or hard resin).

[0050] When it is desired to move the second polishing device 50 more accurately in the axial direction of the cylindrical body 200, the second moving mechanism 80 may be provided with, in addition to the second moving part (wheel 57), a second guide part (for example, a rail) that is installed outside the cylindrical body 200 and extends in the axial direction along the outer circumferential surface 202 of the cylindrical body 200. For example, a rail similar to the rail 21 shown in Figures 1 and 2 may be installed outside the cylindrical body 200, and the wheels 57 may be fitted to the rail to guide the second polishing device 50.

[0051] The wheels 57 provided on the second polishing apparatus 50 are specifically attached to the underside of a flat stand 58. Meanwhile, the second polishing apparatus 50, which is equipped with a screw conveyor 60 and a transport elevator 61 as transport devices, is placed on the upper surface of the stand 58. That is, in this embodiment, the wheels 57 are indirectly provided on the second polishing apparatus 50.

[0052] In this embodiment, a control unit may be provided to control the rotation speed of the wheels 22 and 57, start and stop of movement, etc., in order to link the operation of the first polishing apparatus 10 and the operation of the second polishing apparatus 50. The control unit may be remotely operable, or a control panel may be provided directly or indirectly on the first polishing apparatus 10 and the second polishing apparatus 50, and an operator may directly operate the control panel to control them.

[0053] [Second polishing device] Next, the second grinding device 50 will be described. As described above, the second grinding device 50 is directly or indirectly equipped with wheels 57. In this embodiment, the second grinding device 50 is mounted on a stand 58, and is movable along the outer circumferential surface 202 outside the cylindrical body 200 by the wheels 57 attached to the stand 58.

[0054] The second polishing device 50 has an injection unit 51 capable of injecting an abrasive toward the outer peripheral surface 202 of the cylindrical body 200. The second polishing device 50 is a so-called blasting device, and there are no particular limitations on the type of abrasive used or the structure of the injection unit 51. For example, the second polishing device 50 can be a shot blasting device that includes a rotor 52, a motor 53, and an injection unit 51, similar to the first polishing device 10 described in the first embodiment.

[0055] The second polishing device 50 is attached to and supported by a cabinet 54. In this embodiment, the cabinet 54 also serves as a hopper 55. For example, in this embodiment, the cabinet 54 is a generally box-shaped body with a large opening on one side. The open end of the cabinet 54 abuts or is close to the outer peripheral surface 202, and the opening covers an injection area where the abrasive injected from the injection unit 51 abuts. The rotor 52 and motor 53 are attached to the bottom surface of the generally box-shaped body, on the side opposite the surface facing the outer peripheral surface 202, and the injection unit 51 is attached to an opening formed in a predetermined location on the bottom surface. Elastic wall portions 56 are provided at the open ends of the box-shaped body to allow the bottom and side surfaces of the box-shaped cabinet 54 to function as a hopper 55. The elastic wall portions 56 are configured similarly to the elastic wall portions 41 in the first embodiment, and therefore will not be described in detail here.

[0056] An abrasive recovery section 59 is provided below the hopper 55. The abrasive recovered by the hopper 55 and flowing down the abrasive recovery section 59 is transported horizontally by a screw conveyor 60 provided downstream of the abrasive recovery section 59, and then transported upward by a transport elevator 61. A tank 70 for storing the abrasive is provided above the transport elevator 61, and the transported abrasive is stored in the tank 70. An internal air dust collector 71 is provided above the tank 70 to collect dust that has risen into the transport section. Before starting use of the second polishing device 50, abrasive can be supplied through an openable inlet 64, transported by the transport elevator 61, and stored in the tank 70. The abrasive stored in the tank 70 is supplied to the rotor 52 through the feed pipe 74 by its own weight, bounced off the rotating blades of the rotor 52, and ejected from the ejection part 51 to collide with the outer peripheral surface 202.

[0057] There are no particular limitations on the amount, density, and speed of the abrasive projected in the second polishing mechanism 120. For example, when polishing the inner peripheral surface 201 and the outer peripheral surface 202 simultaneously, the above-mentioned projection speed may be adjusted in the same manner as in the first polishing device 10. The amount and density of the abrasive projected in the second polishing device 50 can be adjusted as appropriate based on factors such as the distance between the projection unit 51 and the outer peripheral surface 202.

[0058] The injecting unit 51 has an injection opening for injecting the abrasive ejected by the rotor 52. The position of the second grinding device 50 is adjusted so that the injection opening faces a desired region of the outer circumferential surface 202. In this embodiment, the installation position of the second grinding device 50 is adjusted so that the abrasive ejected from the injecting unit 51 is projected below half the height of the outer circumferential surface 202 of the cylindrical body 200 in the vertical direction. By injecting the abrasive upward in this manner, the ejected abrasive falls under its own weight toward the abrasive recovery unit 59 provided below the hopper 55, making recovery easy. In addition, the second grinding device 50 can be positioned close enough to the cylindrical body 200, allowing for efficient use of the work space.

[0059] Third Embodiment Next, the cylindrical body polishing method of the present invention will be described. The cylindrical body polishing method of the present invention is carried out using the cylindrical body polishing structure of the present invention. The cylindrical body polishing method can be broadly divided into three modes by varying the timing of the polishing device and the cylindrical body operation. Two of these three modes will be specifically described as the third embodiment and the fourth embodiment described below. Note that the third and fourth embodiments describe embodiments using a cylindrical body polishing structure 120 in which a first polishing device 10 is arranged inside the cylindrical body 200 and a second polishing device 50 is arranged outside. However, the cylindrical body polishing method of the present invention also includes modes carried out using a cylindrical body polishing structure in which a first polishing device 10 is arranged inside the cylindrical body 200 and a second polishing device 50 is not arranged outside.

[0060] First, a first aspect of the cylindrical body polishing method of the present invention will be described as a third embodiment. FIG. 5 will be used as appropriate to describe the third embodiment. FIG. 5 is a conceptual diagram for explaining the cylindrical body polishing method according to the third embodiment of the present invention. The left side of FIGS. 5A to 5D shows a conceptual diagram observed from a direction perpendicular to the axial direction of the cylindrical body 200. The second polishing device 50 installed outside the cylindrical body 200 is not shown in these figures. Alternatively, the right side of FIGS. 5A to 5D shows a conceptual diagram observed from the axial direction of the cylindrical body 200. These figures show a state in which a first polishing device 10 is installed inside the cylindrical body 200 and a second polishing device 50 is installed outside the cylindrical body 200.

[0061] The cylindrical body polishing method of the third embodiment is a polishing method for polishing the inner circumferential surface 201 and the outer circumferential surface 202 of a cylindrical body 200 using the cylindrical body polishing structure 120 described in the second embodiment. First, as shown in FIG. 5A , a first polishing device 10 is disposed inside the cylindrical body 200 so as to be movable in the axial direction of the cylindrical body 200 by a first moving mechanism 20, and a second polishing device 50 is disposed outside the cylindrical body 200 so as to be movable in the axial direction of the cylindrical body 200 by a second moving mechanism 80. Note that for the first moving mechanism 20 and the second moving mechanism 80, the descriptions of the first and second embodiments and FIGS. 1, 2, and 4 described above are referred to as appropriate.

[0062] Next, the first step of this embodiment is initiated. As shown in FIG. 5B , the first step is a process in which, while the cylindrical body 200 is fixed, polishing is initiated by the first polishing device 10, and the first moving mechanism 20 moves the first polishing device 10 from a predetermined position on one end of the cylindrical body 200 to a predetermined position on the other end. As a result, the projection area 85 on the inner circumferential surface 201 onto which the abrasive ejected from the first polishing device 10 is projected moves in a strip-like manner in the axial direction of the cylindrical body 200. In other words, a polished surface of a predetermined width is formed in a strip-like manner on the inner circumferential surface 201 in the axial direction. Furthermore, in this embodiment, in the first step, simultaneously with the operation of the first polishing device 10 described above, the second polishing device 50 is moved by the second moving mechanism 80 from a predetermined position on one end of the cylindrical body 200 to a predetermined position on the other end. As a result, the outer circumferential surface 202 is polished in a strip-like manner in the axial direction of the cylindrical body 200. Here, simultaneous operation of the first polishing apparatus 10 and the second polishing apparatus 50 does not only mean that the start timing and movement speed are completely identical, but also means that the operation times of both apparatuses overlap partially.

[0063] After the first step is completed, the second step of this embodiment is performed. As shown in FIG. 5C , the second step is a process in which, after the first grinding device 10 and the second grinding device 50 arrive at a predetermined position on the other axial end of the cylindrical body 200, the movement of the first grinding device 10 and the second grinding device 50 is stopped and the cylindrical body 200 is rotated a predetermined angle around its axis. At this time, as shown in FIG. 5C , the injection of the abrasive by the first grinding device 10 and the second grinding device 50 may or may not be stopped. The predetermined angle is not particularly limited. For example, the cylindrical body 200 may be rotated until the projection area 85 of the first grinding device 10 and the second grinding device 50 is removed from part or all of the surface polished in the first step.

[0064] After the second step described above is completed, as shown in Fig. 5D, the direction of movement of the first polishing device 10 and the second polishing device 50 is changed from the other end side of the cylindrical body 200 toward the one end side, and the first step is repeated. This makes it possible to polish a band-like area different from the projection area 85 described in Fig. 5B. Then, when the first polishing device 10 and the second polishing device 50 arrive at a predetermined position on the one end side, the second step is repeated.

[0065] In this manner, the first step and the second step are repeated until the entire inner circumferential surface 201 and the entire outer circumferential surface 202 of the cylindrical body 200 are polished, thereby polishing the cylindrical body 202. Although the third embodiment of the cylindrical body polishing method of the present invention has been described above using an example in which the first step and the second step are carried out independently, the present invention is not limited to this, and the final stage of the first step and the initial stage of the second step may be carried out in an overlapping manner. In other words, the cylindrical body 200 may start to rotate and the second step may be started at the timing when the first polishing device 10 and the second polishing device 50 are still moving at the final stage of the first step. Similarly, the end of the second step and the beginning of the repeated first step may be performed in an overlapping manner. That is, at the end of the second step, while the cylindrical body 200 is still rotating, the movement of the first grinding device 10 and the second grinding device 50 may be started, and the first step may be repeated.

[0066] <Fourth embodiment> Next, a cylindrical body polishing method according to a fourth embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a conceptual diagram for explaining a cylindrical body polishing method according to the fourth embodiment of the present invention. 6A to 6D show conceptual diagrams observed from a direction perpendicular to the axial direction of the cylindrical body 200. The second polishing device 50 installed outside the cylindrical body 200 is not shown in these diagrams. Furthermore, the right side of the diagrams of Fig. 6A to 6D show conceptual diagrams observed from the axial direction of the cylindrical body 200. These diagrams show a state in which the first polishing device 10 is installed inside the cylindrical body 200 and the second polishing device 50 is installed outside.

[0067] The cylindrical body polishing method of the fourth embodiment is a polishing method for polishing the inner circumferential surface 201 and the outer circumferential surface 202 of a cylindrical body 200 using the cylindrical body polishing structure 120 described in the second embodiment. First, as shown in Fig. 6A, a first polishing device 10 is disposed inside the cylindrical body 200 so as to be movable in the axial direction of the cylindrical body 200 by a first moving mechanism 20, and a second polishing device 50 is disposed outside the cylindrical body 200 so as to be movable in the axial direction of the cylindrical body 200 by a second moving mechanism 80.

[0068] Next, the first step is started. In the first step of this embodiment, as shown in FIG. 6B , the positions of the first polishing device 10 and the second polishing device 50 are fixed, and polishing is started by injecting an abrasive. At the same time, the cylindrical body 200 is rotated about its axis to polish the inner circumferential surface 201 and the outer circumferential surface 202 in the circumferential direction. As a result, the projection area 85 on the inner circumferential surface 201 onto which the abrasive injected from the first polishing device 10 is projected moves continuously in the circumferential direction, and the projection area 85 on the outer circumferential surface 202 onto which the abrasive injected from the second polishing device 50 is projected also moves continuously in the circumferential direction.

[0069] The first step is completed when the inner circumferential surface 201 and the outer circumferential surface 202 of the cylindrical body 200 are polished in a ring-like shape in the circumferential direction within a predetermined width in the axial direction of the cylindrical body 200 by the above-described first step. Next, as shown in FIG. 6C , a second step is performed in which the rotation of the cylindrical body 200 is stopped and the first polishing device 10 and the second polishing device 50 are moved a predetermined distance in the axial direction of the cylindrical body 200 by the first moving mechanism 20 and the second moving mechanism 80. At this time, as shown in FIG. 6C , the injection of the abrasive by the first polishing device 10 and the second polishing device 50 may or may not be stopped. The predetermined distance is not particularly limited. For example, the first polishing device 10 and the second polishing device 50 may be moved until the projection areas 85 of the first polishing device 10 and the second polishing device 50 are removed from part or all of the surface polished in the first step.

[0070] After the second step described above is completed, as shown in Fig. 6D, the positions of the first polishing device 10 and the second polishing device 50 are fixed and polishing begins, and the cylindrical body 200 is rotated about its axis to repeat the first step of polishing the inner circumferential surface 201 and the outer circumferential surface 202 in the circumferential direction. This allows a region different from the projection region 85 described in Fig. 6B to be polished in a ring shape.

[0071] In this manner, the first step and the second step are repeated until the entire inner circumferential surface 201 and the entire outer circumferential surface 202 of the cylindrical body 200 are polished, thereby polishing the cylindrical body 202. Although the fourth embodiment of the cylindrical body polishing method of the present invention has been described above using an example in which the first step and the second step are carried out independently, the present invention is not limited to this, and the final stage of the first step and the initial stage of the second step may be carried out in an overlapping manner. In other words, the first polishing device 10 and the second polishing device 50 may start to move at a timing when the cylindrical body 200 is still rotating at the final stage of the first step, and the second step may be started. Similarly, the end of the second step and the beginning of the repeated first step may be performed in an overlapping manner. That is, at the end of the second step, while the first grinding device 10 and the second grinding device 50 are still moving, the rotation of the cylindrical body 200 may be started and the first step may be repeated.

[0072] The first to fourth embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments and also includes various modifications, improvements, and other aspects as long as the object of the present invention is achieved. For example, in the first embodiment, the rail base 81 shown in FIGS. 1 and 2 may be omitted, and two or more casters 23 may be arranged in the axial direction of the cylindrical body 200, with the inner peripheral surface 201 directly supporting the rail. Alternatively, one of the rail bases 81 may be omitted to support only one end of the rail 21, and the rail 21 may be configured to be extendable and retractable toward the other end. The extendable rail 21 on which the first grinding device 10 is installed may be inserted from one opening of the cylindrical body 200, and the rail 21 may be extended and retracted while grinding is being performed to move the first grinding device 10 inside the cylindrical body 200.

[0073] The cylindrical body polishing method of the present invention also encompasses an embodiment in which the first polishing device 10 is moved by the first moving mechanism 20 and the cylindrical body 200 is rotated about its axis, thereby polishing the inner peripheral surface 201 of the cylindrical body 200 in a spiral shape. Furthermore, the cylindrical body polishing method of the present invention also encompasses an embodiment in which the first polishing device 10 is moved by the first moving mechanism 20 and the second polishing device 50 is moved by the second moving mechanism 80, while the cylindrical body 200 is rotated about its axis, thereby polishing the inner peripheral surface 201 and the outer peripheral surface 202 of the cylindrical body 200 in a spiral shape.

[0074] The above embodiment encompasses the following technical ideas. (1) A cylindrical body polishing structure for polishing the inner peripheral surface of a cylindrical body, a first polishing device disposed inside the cylindrical body and having an injection part capable of injecting an abrasive toward an inner peripheral surface of the cylindrical body; a first moving mechanism for moving the first grinding device in an extension direction of the cylindrical body; a rotation mechanism for rotating the cylindrical body around an axis; A cylindrical body polishing structure comprising: (2) The first moving mechanism is a first guide portion that is inserted into the cylindrical body and extends in the extension direction of the cylindrical body; The cylindrical body polishing structure described in (1) above, comprising a first moving part that supports the first polishing device and is movable along the first guide part. (3) The first guide portion has a rail extending in the extension direction of the cylindrical body and a caster provided on the lower surface side of the rail and capable of contacting the inner circumferential surface, The cylindrical body polishing structure according to (2) above, wherein the axial direction of the rotation axis of the caster is the same as the extension direction of the cylindrical body. (4) a second polishing device that is installed outside the cylindrical body and has an injection part that can inject an abrasive toward the outer peripheral surface of the cylindrical body; A cylindrical body polishing structure described in any one of (1) to (3) above, further comprising a second moving mechanism for moving the second polishing device along the outer surface of the cylindrical body in the extension direction of the cylindrical body. (5) a second guide portion installed outside the cylindrical body and extending in the axial direction along the outer circumferential surface of the cylindrical body; The cylindrical body polishing mechanism according to (4) above, further comprising: a second moving part that supports the second polishing device and is movable along the second guide part. (6) a hopper that covers the injection part of the first polishing device and a projection area on the inner circumferential surface that can be contacted by the abrasive injected from the injection part; The cylindrical body polishing mechanism according to any one of (1) to (5) above, further comprising an abrasive recovery section connected to the hopper. (7) A cylindrical body polishing mechanism according to (6) above, wherein the hopper has an elastic wall portion at the end on the inner peripheral surface side, which is made of an elastic material and can abut or come close to the inner peripheral surface. (8) A cylindrical body polishing mechanism according to any one of (1) to (7) above, wherein the cylindrical body has an inner diameter of 150 cm or more. (9) A cylindrical body polishing method for polishing an inner peripheral surface of a cylindrical body using the cylindrical body polishing structure described in any one of (1) to (8) above, the first grinding device is disposed inside the cylindrical body so as to be movable in an extension direction of the cylindrical body by the first moving mechanism; A cylindrical body polishing method, characterized in that the inner peripheral surface of the cylindrical body is polished by any one of the following first to third aspects: The first aspect is a first step of fixing the cylindrical body and moving the first grinding device by the first moving mechanism to grind the inner circumferential surface in a strip shape in an extension direction of the cylindrical body; a second step of stopping the movement of the first grinding device after the first grinding device has reached a predetermined position in the extension direction of the cylindrical body, and rotating the cylindrical body by a predetermined angle around the axis, and repeating this; The second aspect is a first step of fixing the position of the first grinding device and rotating the cylindrical body around its axis to grind the inner circumferential surface in a circumferential direction; a second step in which, after the inner circumferential surface of the cylindrical body has been polished in the circumferential direction within a predetermined width in the extension direction of the cylindrical body by the first step, the rotation of the cylindrical body is stopped and the first polishing device is moved by the first moving mechanism by a predetermined distance in the extension direction of the cylindrical body, and the second step is repeated; The third aspect is In this embodiment, the first grinding device is moved by the first moving mechanism and the cylindrical body is rotated about its axis, thereby grinding the inner peripheral surface of the cylindrical body in a spiral shape. (10) The second grinding device is disposed outside the cylindrical body so as to be movable in the extension direction of the cylindrical body by the second moving mechanism; In the first embodiment, During the first step, the second grinding device is moved by the second moving mechanism to grind the outer circumferential surface in a band shape in the extension direction of the cylindrical body, and When the second step is performed, the movement of the second polishing device is stopped, or In the second embodiment, During the first step, the position of the second grinding device is fixed, and the outer circumferential surface of the cylindrical body rotating around the axis is ground in a circumferential direction; During the second step, the second grinding device is moved a predetermined distance in the extending direction of the cylindrical body, or In the third aspect, the cylindrical body polishing method according to (9) above, wherein the second polishing device is moved together with the first polishing device to polish the approximate number of surfaces in a spiral pattern. [Explanation of symbols]

[0075] 10...First polishing device 11, 51... Injection part 12, 52 rotor 13, 53... Motor 14, 54... Cabinet 15...Arm 16, 23, 29 Caster 20...first movement mechanism 21 Rail 22, 57...wheels 24...wheel engagement part 25···Wheel mounting part 26, 58... Mounting frame 27. Table 28. Height adjustment mechanism 30 Rotation mechanism 31 Turning Roll 32 Turning roll base 40, 55 Hopper 41, 56... Elastic wall portion 42, 59... Abrasive recovery section 43, 74... Feed pipe 44, 70... Tank 45...Aperture 50...Second polishing device 60···Screw conveyor 61. Transport elevator 62 Dust collection flange 63...Lid part 64...Inlet 71...Inside air dust collector 80...Second movement mechanism 81 Rail base 82 Control Panel 83 Dust collector 84···Low lift truck 85...Projection area 86...Operation unit 100, 110, 120... Cylindrical body polishing structure 200, 200'... Cylindrical body 201...Inner peripheral surface 202...Outer surface 203 Worker

Claims

1. A cylindrical body polishing structure for polishing an inner peripheral surface of a cylindrical body, a first polishing device disposed inside the cylindrical body and having an injection part capable of injecting an abrasive toward an inner peripheral surface of the cylindrical body; a first moving mechanism for moving the first grinding device in an extension direction of the cylindrical body; a rotation mechanism for rotating the cylindrical body around an axis; Equipped with The first moving mechanism a first guide portion that is inserted into the cylindrical body and extends in the extension direction of the cylindrical body; a first moving part that supports the first grinding device and is movable along the first guide part, The first guide portion has a rail extending in the extension direction of the cylindrical body and a caster provided on the lower surface of the rail and capable of contacting the inner circumferential surface, The axial direction of the rotation axis of the caster is the same as the extension direction of the cylindrical body. A cylindrical body polishing structure characterized by:

2. a second polishing device having an injection part that is installed outside the cylindrical body and that is capable of injecting an abrasive toward the outer peripheral surface of the cylindrical body; The cylindrical body polishing structure according to claim 1 , further comprising a second moving mechanism for moving the second polishing device along the outer peripheral surface of the cylindrical body in the extension direction of the cylindrical body.

3. a second guide portion that is installed outside the cylindrical body and extends in the extension direction of the cylindrical body along the outer circumferential surface of the cylindrical body; The cylindrical body polishing mechanism according to claim 2 , further comprising: a second moving part that supports the second polishing device and is movable along the second guide part.

4. a hopper that covers the injection part of the first polishing device and a projection area on the inner circumferential surface with which the abrasive injected from the injection part can come into contact; The cylindrical body polishing mechanism according to claim 1 , further comprising: an abrasive recovery section connected to the hopper.

5. 5. The cylindrical body polishing mechanism according to claim 4, wherein the hopper has an elastic wall portion made of an elastic member at an end portion on the inner peripheral surface side, the elastic wall portion being capable of abutting against or approaching the inner peripheral surface.

6. 6. A cylindrical body polishing mechanism according to claim 1, wherein the cylindrical body has an inner diameter of 150 cm or more.

Images