Abrasive bundle holder and abrasive brush

Abstract

To provide an abrasive bundle holder capable of suppressing uneven wear of an abrasive bundle. [Solution] The abrasive bundle holding surface 7 of the abrasive bundle holder 4 is provided with multiple wall portions 11 that protrude from the opening edge 8d of each abrasive bundle holding hole 8 and partially surround the abrasive bundle holding hole 8. Each wall portion 11 has an abrasive bundle support surface 12 that rises from the abrasive bundle holding surface 7 and follows the opening 8c of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 intersects with a first imaginary plane S1 that includes the rotation axis L and the hole axis L1 of the abrasive bundle holding hole 8 on the outer periphery of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 surrounds the abrasive bundle holding hole 8 from the outer periphery. In an abrasive brush 1 in which the base end portion of an abrasive bundle 3 is inserted into the abrasive bundle holding hole 8 of the abrasive bundle holder 4 and fixed to the abrasive bundle holder 4 with an adhesive, the abrasive bundle support surface 12 of the wall portions 11 faces the abrasive bundle 3 from the outer periphery.

Description

[Technical Field]

[0001] The present invention relates to an abrasive bundle holder for holding an abrasive bundle, and an abrasive brush. [Background technology]

[0002] Abrasive brushes comprising an abrasive bundle consisting of a plurality of linear abrasives bundled together and an abrasive bundle holder for holding the abrasive bundle are described in Patent Documents 1 and 2. In these documents, the abrasive bundle holder has a cylindrical body. One axial end face of the body along the axis is a flat abrasive bundle holding surface. The abrasive bundle holding surface has a plurality of abrasive bundle holding holes. The plurality of abrasive bundle holding holes are arranged in a ring shape around the axis. The abrasive bundles are inserted at their base ends into the abrasive bundle holding holes and fixed to the abrasive bundle holder by an adhesive that hardens in the abrasive bundle holding holes. The linear abrasives are made by impregnating and hardening a resin into a bundle of inorganic long fibers. The inorganic long fibers are, for example, alumina long fibers.

[0003] The abrasive bundle holder described in Patent Document 1 has a shaft that protrudes from a body on the side opposite to the abrasive bundle holding surface. The shaft is coaxial with the body. When polishing a workpiece, the abrasive brush is connected to a machine tool at the shaft and rotated around the rotation axis. Furthermore, when polishing a workpiece, the abrasive brush is placed in a state where the tip of each abrasive bundle is in contact with the surface of the workpiece to be polished at a predetermined cutting depth.

[0004] The abrasive bundle holder described in Patent Document 2 has a through hole at the center of the body that passes through the body in the axial direction. A female thread is provided on the inner surface of the through hole. A plurality of abrasive bundle holding holes are arranged surrounding the through hole. The abrasive brush is used while held by the abrasive tool holder. The abrasive tool holder has a shaft that is inserted into the through hole. A male thread is provided on the outer surface of the shaft that screws into the female thread of the through hole of the abrasive bundle holder. When polishing a workpiece, the abrasive brush is connected to a machine tool via the abrasive tool holder and rotated around the rotation axis. Furthermore, when polishing a workpiece, the abrasive brush is in a state where the tip of each abrasive bundle contacts the surface of the workpiece to be polished with a predetermined cutting depth. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2023 / 042385 [Patent Document 2] International Publication No. 2019 / 138595 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the inventors' verification, with the above-mentioned abrasive brush, when a polishing process is performed in which a plurality of workpieces are polished one after another in succession, uneven wear may occur in each of the abrasive bundles held in each of the plurality of abrasive bundle holding holes. Specifically, as the bristle length of the abrasive bundles becomes shorter due to wear caused by polishing the workpieces, uneven wear occurs in each abrasive bundle held in each abrasive bundle holding hole of the abrasive bundle holder, in which the wear of the linear abrasive located at the outer end portion in the radial direction centered on the axis of the abrasive bundle holder becomes less than the wear of the linear abrasive located further inward.

[0007] Here, if uneven wear occurs in the abrasive bundle when the polishing process is completed, the bristle length of the abrasive bundle protruding from the abrasive bundle holding surface will not be measured accurately, and an error will occur. Therefore, when the next polishing process is started, if the position of the polishing brush relative to the surface to be polished of the workpiece is set based on the bristle length of the abrasive bundle including the measurement error, a discrepancy will occur between the set value and the actual cutting depth. If the abrasive bundle is unevenly worn, the precision with which the workpiece is polished may decrease.

[0008] In view of the above, an object of the present invention is to provide an abrasive bundle holder that can prevent uneven wear of the abrasive bundles held in the abrasive bundle holding holes, and also to provide a polishing brush that can prevent uneven wear of the abrasive bundles. [Means for solving the problem]

[0009] After careful consideration, the inventors have found that the reason why, as the bristle length of the abrasive bundles becomes shorter during polishing of the workpiece, the linear abrasives located at the outer end portions of each abrasive bundle held in each abrasive bundle holding hole of the abrasive bundle holder wear less than the linear abrasives located further inward is as follows.

[0010] When a workpiece is polished, as the abrasive bundle holder rotates around its axis of rotation, centrifugal force causes the tip of each abrasive bundle to bend outward. When the tip of each abrasive bundle is brought into contact with the surface of the workpiece to be polished in this state, the linear abrasives located at the outermost end of each abrasive bundle bend outward, allowing them to escape the force from the surface to be polished. In contrast, the linear abrasives located at the innermost end are more likely to bend outward than the linear abrasives located at the outermost end, due to the presence of more linear abrasives on their outer periphery, and are therefore less likely to escape the force from the polishing surface. As the bristles of the abrasive bundle become shorter during polishing, the rigidity of each linear abrasive constituting the abrasive bundle increases accordingly. As a result, the linear abrasives located at the innermost end, which are less likely to escape the force from the polishing surface, are more likely to cut into the surface to be polished. As a result, the linear abrasives located at the innermost end are more likely to wear out. On the other hand, even if the rigidity of the linear abrasive material at the end portion on the outer periphery is increased, it can bend toward the outer periphery and release the force from the surface to be polished, compared to the linear abrasive material at the inner periphery. As a result, the wear of the linear abrasive material at the end portion on the outer periphery is less than the wear of the linear abrasive material located further inward. As a result, uneven wear occurs in the abrasive bundle. The present invention is based on such new findings by the inventors.

[0011] In order to solve the above-mentioned problems, the abrasive bundle holder of the present invention has an abrasive bundle holding surface that is perpendicular to a rotation axis and a plurality of abrasive bundle holding holes provided in the abrasive bundle holding surface, the plurality of abrasive bundle holding holes are circular and arranged in an annular shape around the rotation axis, and a wall portion that protrudes from the abrasive bundle holding surface and partially surrounds the abrasive bundle holding hole is provided at the opening edge of each abrasive bundle holding hole, and each wall portion has an abrasive bundle support surface that rises from the abrasive bundle holding surface and follows the opening of the abrasive bundle holding hole, and the rotation axis is centered. In the radial direction around the center, if the side where the rotation axis is located is the inner side and the opposite side is the outer side, each wall portion has an abrasive bundle support surface that rises from the abrasive bundle holding surface and follows the opening of the abrasive bundle holding hole, and the abrasive bundle support surface intersects with a first imaginary plane that includes the rotation axis and the hole axis of the abrasive bundle holding hole on the outer side of the abrasive bundle holding hole, and the angular range over which the abrasive bundle support surface extends is an angular range of 135° or more and 240° or less around the hole axis.

[0012] In the present invention, the abrasive bundle holding surface of the abrasive bundle holder is provided with multiple wall portions that protrude from the opening edges of each abrasive bundle holding hole and partially surround the abrasive bundle holding hole. Each wall portion has an abrasive bundle support surface that rises from the abrasive bundle holding surface and runs along the opening of the abrasive bundle holding hole. The abrasive bundle support surface intersects with a first imaginary plane that includes the rotation axis and the hole axis of the abrasive bundle holding hole on the outer periphery of the abrasive bundle holding hole. Furthermore, the angle range over which the abrasive bundle support surface extends is 135° to 240° around the hole axis. With this configuration, at least a portion of the abrasive bundle support surface surrounds the abrasive bundle holding hole from the outer periphery. Therefore, when abrasive bundles are inserted and fixed at their base ends in each of the multiple abrasive bundle holding holes formed annularly in the abrasive bundle holding surface to form an abrasive brush, the abrasive bundle support surface of the wall portion faces the abrasive bundles from the outer periphery. Therefore, when the tip of each abrasive bundle is brought into contact with the surface to be polished of the workpiece while the abrasive bundle holder is rotated around the rotation axis, The abrasive bundle support surface prevents the linear abrasives located at the outer peripheral end of each abrasive bundle from bending outward, and therefore the amount of wear of the linear abrasives located at the outer peripheral end of each abrasive bundle due to polishing of the workpiece can be made to approach the amount of wear of the linear abrasives located further inward.

[0013] In addition, in the present invention, the abrasive bundle support surface extends over an angular range of 135° to 240° around the hole axis. By extending the abrasive bundle support surface over such an angular range, it is possible to restrict the bending of the linear abrasive material located at the outer end of each abrasive bundle toward the periphery and in the circumferential direction. This, in turn, suppresses uneven wear of the abrasive bundle. Note that if the abrasive bundle support surface is provided over an angular range exceeding 240° around the hole axis, the peripheral wall will surround nearly the entire circumference of the abrasive bundle holding hole. As a result, uneven wear of each abrasive bundle will occur similarly to when no wall portion is provided. Therefore, the abrasive bundle support surface is limited to an angular range of 240° or less around the hole axis.

[0014] In the present invention, when a plane including the hole axis and perpendicular to the first imaginary plane is defined as a second imaginary plane, (1) the entire abrasive bundle support surface may be located on the outer circumferential side of the second imaginary plane, or (2) at the opening edge of each abrasive bundle holding hole, the entire region where the abrasive bundle support surface is not present may be located on the inner circumferential side of the second imaginary plane. When the entire abrasive bundle support surface is located on the outer circumferential side of the second imaginary plane, when the tip portions of each abrasive bundle are brought into contact with the surface to be polished of the workpiece while the abrasive bundle holder is rotated about the rotation axis, the abrasive bundle support surface can easily prevent the linear abrasive located at the outer end portion of each abrasive bundle from bending outward and in the circumferential direction. Furthermore, even if the entire area at the opening edge of each abrasive bundle holding hole where no abrasive bundle support surface is provided is located on the inner side of the second imaginary plane, when the abrasive bundle holder is rotated around the rotation axis and the tip portion of each abrasive bundle is brought into contact with the surface of the workpiece to be polished, the abrasive bundle support surface can easily prevent the linear abrasive located at the outer end portion of each abrasive bundle from bending outer and circumferentially.

[0015] In the present invention, the abrasive bundle support surface may be provided at the opening edge in an area of ​​120° or less from the first imaginary plane to one side and the other side about the hole axis. In this way, when the abrasive bundle holder is rotated about the rotation axis and the tip portions of the abrasive bundles are brought into contact with the surface to be polished of the workpiece, the abrasive bundle support surface can easily prevent the linear abrasives located at the outer end portions of the abrasive bundles from bending outward and in the circumferential direction.

[0016] In the present invention, the abrasive bundle support surface may have a shape symmetrical with respect to the first imaginary plane. In this way, when a workpiece is polished by rotating an abrasive brush having base ends of abrasive bundles inserted and fixed into a plurality of abrasive bundle holding holes formed annularly on the abrasive bundle holding surface, it is possible to restrict bending of the linear abrasives located at the outer peripheral ends of each abrasive bundle outward in the radial direction and bending of the linear abrasives in the circumferential direction, regardless of the direction in which the abrasive brush rotates around the rotation axis.

[0017] In the present invention, the abrasive bundle support surface rises perpendicularly from the abrasive bundle holding surface, and the height dimension of the abrasive bundle support surface protruding from the abrasive bundle holding surface is preferably 2 mm or more and 3 mm or less. In this way, when the bristle length of the abrasive bundles is shortened, the bending of the linear abrasives located at the outer end portions of each abrasive bundle held in each abrasive bundle holding hole of the abrasive bundle holder in the outer and circumferential directions can be restricted. Therefore, the wear amount of the linear abrasives located at the outer end portions of each abrasive bundle can be made to be closer to the wear amount of the linear abrasives located further inward. Furthermore, if the height dimension of the abrasive bundle support surface is 3 mm or less, even if a wall portion is provided on the abrasive bundle holding surface, the abrasive bundles held in the abrasive bundle holding holes can be raised to a height close to the abrasive bundle holding surface. It can be used.

[0018] In the present invention, the contour shape of the abrasive bundle holding surface is a regular polygon, and the abrasive bundle holding surface is provided with the abrasive bundle holding holes in the same number as the number of corners of the contour shape of the abrasive bundle holding surface, each abrasive bundle holding hole being provided at an inside corner of each corner of the contour shape of the abrasive bundle holding surface, and the multiple wall portions can be continuous in the circumferential direction around the rotation axis.

[0019] In the present invention, a through hole may be provided, and the through hole may be provided coaxially with the rotation shaft on the inner peripheral side of the plurality of abrasive bundle holding holes.

[0020] Next, another form of an abrasive bundle holder of the present invention has an abrasive bundle holding surface perpendicular to the rotation axis and a plurality of abrasive bundle holding holes provided in the abrasive bundle holding surface, the plurality of abrasive bundle holding holes being arranged in a ring shape around the rotation axis, and the opening edge of each abrasive bundle holding hole being provided with a wall portion protruding from the abrasive bundle holding surface and partially surrounding the abrasive bundle holding hole, and in the radial direction centered on the rotation axis, when the side where the rotation axis is located is the inner side and the opposite side is the outer side, each wall portion is located on the outer side of an imaginary cylindrical surface connecting the axis lines of the abrasive bundle holding holes, and is provided with an abrasive bundle support surface that rises from the abrasive bundle holding surface and follows the opening of the abrasive bundle holding hole, and the angle range over which the abrasive bundle support surface extends is 135° or more and 203° or less around the hole axis.

[0021] In the present invention, the abrasive bundle holding surface of the abrasive bundle holder is provided with multiple wall portions that protrude from the opening edges of each abrasive bundle holding hole and partially surround the abrasive bundle holding hole. Each wall portion has an abrasive bundle support surface that rises from the abrasive bundle holding surface and follows the opening of the abrasive bundle holding hole. The abrasive bundle support surface is located on the outer periphery of an imaginary cylindrical surface connecting the axes of each abrasive bundle holding hole, and the abrasive bundle support surface extends within an angular range of 135° to 203° from the hole axis center. With this configuration, the abrasive bundle support surface surrounds the abrasive bundle holding hole from the outer periphery. Therefore, when abrasive bundles are inserted and fixed at their base ends in each of the multiple abrasive bundle holding holes formed annularly in the abrasive bundle holding surface to form an abrasive brush, the abrasive bundle support surface of the wall portion faces the abrasive bundles from the outer periphery. Therefore, when the abrasive bundle holder is rotated around the rotation axis and the tip portions of each abrasive bundle are brought into contact with the surface to be polished of the workpiece, the abrasive bundle support surface prevents the linear abrasives located at the outer end portions of each abrasive bundle from bending outward. Therefore, the amount of wear of the linear abrasives located at the outer end portions of each abrasive bundle during polishing of the workpiece can be made to be closer to the amount of wear of the linear abrasives located further inward. Furthermore, according to the present invention, even if the abrasive bundle holding holes are not circular, a portion of the abrasive bundle support surface surrounds the abrasive bundle holding holes from the outer periphery. Therefore, when a polishing brush is constructed by inserting and fixing the base ends of abrasive bundles into each of the multiple abrasive bundle holding holes arranged in an annular pattern on the abrasive bundle holding surface, the abrasive bundle support surface of the wall portion faces the abrasive bundles from the outer periphery. Therefore, when the abrasive bundle holder is rotated around the rotation axis and the tip portion of each abrasive bundle is brought into contact with the surface of the workpiece to be polished, the abrasive bundle support surface can prevent the linear abrasive located at the outer end portion of each abrasive bundle from bending toward the outer periphery.

[0022] In the present invention, it is desirable that the abrasive bundle support surface is provided within an angular range of 145° or more and 203° or less about the hole axis.

[0023] In the present invention, it is more desirable that the abrasive bundle support surface be provided within an angle range of 155° to 203° about the hole axis.

[0024] Next, the abrasive brush of the present invention has the above-mentioned abrasive bundle holder and a plurality of abrasive bundles, each abrasive bundle being a bundle of a plurality of linear abrasives, the base end portion of which is inserted into the abrasive bundle holding hole, and which is held by the abrasive bundle holder by an adhesive hardened within the abrasive bundle holding hole, and which can be rotated around the rotation axis of the abrasive bundle holder to polish a workpiece. .

[0025] In the present invention, when the abrasive brush is rotated around the rotation axis to polish a workpiece, the abrasive bundle support surface of the abrasive bundle holder can prevent the linear abrasives located at the outer end portions of each abrasive bundle from bending toward the outer periphery. Therefore, uneven wear of the abrasive bundles can be suppressed. Therefore, when the workpiece is polished, the amount of wear of the linear abrasives located at the outer end portions of each abrasive bundle can be made closer to the amount of wear of the linear abrasives located closer to the inner periphery. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. 2 is a front view of the abrasive bundle holder as viewed from the abrasive bundle holding surface side. [Figure 4] FIG. 2 is a partially enlarged view of the peripheral portion of the abrasive bundle support surface. [Figure 5] 10 is a rear view of the abrasive bundle holder as seen from the side opposite to the abrasive bundle holding surface. FIG. [Figure 6] FIG. 4 is a cross-sectional view of the abrasive bundle holder taken along line AA in FIG. 3. [Figure 7] FIG. 1 is an explanatory diagram of a conventional abrasive brush. [Figure 8] 1 is a graph showing the relationship between the bristle length and the height difference of the linear abrasive material at the tip portion of the abrasive material bundle in a conventional abrasive brush. [Figure 9] 1 is a partially enlarged photograph of the tip portion of an abrasive bundle in a conventional abrasive brush in which the bristles have worn down. [Figure 10]1 is a graph showing the relationship between the bristle length and the height difference of the linear abrasive material at the tip of the abrasive material bundle in the abrasive brush of this example. [Figure 11] 1 is a partially enlarged photograph of the tip portion of the abrasive bundle in the abrasive brush of this example, in which the bristles have worn down. [Figure 12] 10A and 10B are diagrams illustrating verification results regarding the angle range over which the abrasive bundle support surface extends. [Figure 13] This is an enlarged photograph of the tip of an abrasive bundle in an abrasive brush using an abrasive bundle holder in which a wall portion is arranged in a ring shape on the outer peripheral edge of the abrasive bundle holding surface, and the bristles have worn down. [Figure 14] FIG. 10 is an explanatory diagram of an abrasive bundle holder according to a first modified example. [Figure 15] FIG. 10 is an explanatory diagram of an abrasive bundle holder according to a second modified example. [Figure 16] FIG. 10 is an explanatory diagram of an abrasive bundle holder according to a third modified example. [Figure 17] FIG. 10 is an explanatory diagram of an abrasive bundle holder according to a fourth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A polishing brush and an abrasive bundle holder according to an embodiment of the present invention will now be described with reference to the drawings.

[0028] (abrasive brush) FIG. 1 is a perspective view of the abrasive brush 1. FIG. 2 is a perspective view of the abrasive bundle holder 4. FIG. 3 is a front view of the abrasive bundle holder 4 when viewed from the abrasive bundle holding surface 7 side. FIG. 4 is a partially enlarged view of the periphery of the abrasive bundle support surface 12 when the abrasive bundle holder 4 is viewed from the axial direction X. FIG. 5 is a rear view of the abrasive bundle holder 4 when viewed from the opposite side to the abrasive bundle holding surface 7. FIG. 6 is a cross-sectional view of the abrasive bundle holder 4 taken along line AA in FIG. 2.

[0029] As shown in FIG. 1, the abrasive brush 1 of this example includes a plurality of abrasive bundles 3 and an abrasive bundle holder 4 that holds these abrasive bundles 3. The abrasive bundle 3 is a plurality of linear abrasives 2 arranged in parallel. In this example, the linear abrasives 2 are made by impregnating a mass of inorganic long fibers with a resin and hardening the resin. The inorganic long fibers are alumina fibers, silicon carbide fibers, carbon fibers, silicon nitride fibers, or glass fibers. In this example, the inorganic long fibers are alumina fibers. The abrasive bundles 3 have their base ends (one end of the abrasive bundles 3) inserted into abrasive bundle holding holes 8 provided in the abrasive bundle holder 4. The abrasive bundles 3 are also held at their base ends by a resin member 5 against the abrasive bundle holder. The abrasive bundle 3 is held by the abrasive bundle holder 4. The resin member 5 is an adhesive that hardens within the abrasive bundle holding hole 8, and fixes the abrasive bundle 3 to the abrasive bundle holder 4. When the abrasive bundle 3 is held by the abrasive bundle holder 4, the abrasive bundle 3 protrudes in a direction along the rotation axis L of the abrasive bundle holder 4.

[0030] When polishing a workpiece, the polishing brush 1 is held in a tool holder. The polishing brush 1 is connected to a machine tool and rotated around a rotation axis L. The polishing brush 1 is brought into a state in which the tip of each abrasive bundle 3 is in contact with the surface of the workpiece to be polished at a predetermined depth of cut.

[0031] (abrasive bundle holder) As shown in FIG. 2, the abrasive bundle holder 4 has a rectangular prism shape. The abrasive bundle holder 4 has an abrasive bundle holding surface 7 perpendicular to the rotation axis L of the abrasive bundle holder 4 and a plurality of abrasive bundle holding holes 8 formed in the abrasive bundle holding surface 7. As shown in FIG. 3, the outline of the abrasive bundle holder 4 when viewed from the axial direction X along the rotation axis L is a regular heptagon. The outline of the abrasive bundle holder 4 and the outline of the abrasive bundle holding surface 7 are identical. The abrasive bundle holder 4 also has a through hole 10 penetrating in the axial direction X. The through hole 10 is coaxial with the rotation axis L. In this example, a female thread 10a is formed on the inner circumferential surface of the through hole 10. Here, the tool holder that holds the abrasive bundle holder 4 has a shaft with a male thread that screws into the female thread 10a of the abrasive bundle holder 4.

[0032] As shown in FIG. 3 , the abrasive bundle holding surface 7 is provided with a number of abrasive bundle holding holes 8 equal to the number of corners 7a of the regular polygonal contour of the abrasive bundle holding surface 7. The multiple abrasive bundle holding holes 8 are arranged in a ring shape around the rotation axis L. The multiple abrasive bundle holding holes 8 are also provided at the inner corners of the corners 7a of the contour of the abrasive bundle holding surface 7. Each abrasive bundle holding hole 8 is circular and recessed in the axial direction X. As shown in FIG. 6 , the hole axis L1 of each abrasive bundle holding hole 8 extends through the center of the hole 8 in the axial direction X and is parallel to the rotation axis L. Each abrasive bundle holding hole 8 has a circular bottom surface 8a and an inner peripheral wall surface 8b rising from the bottom surface 8a in the axial direction X. Hereinafter, the direction centered on the rotation axis L will be referred to as the radial direction, and the side where the rotation axis L is located in the radial direction will be referred to as the inner peripheral side, and the opposite side will be referred to as the outer peripheral side.

[0033] As shown in FIG. 3 , the opening edge 8d of each abrasive bundle holding hole 8 in the abrasive bundle holding surface 7 is provided with a plurality of wall portions 11 that protrude from the abrasive bundle holding surface 7 and partially surround each abrasive bundle holding hole 8. As shown in FIG. 4 , the opening edge 8d is a region of a certain width adjacent to the opening 8c of each abrasive bundle holding hole 8 in the abrasive bundle holding surface 7. Each wall portion 11 has an abrasive bundle support surface 12 that is perpendicular to the abrasive bundle holding surface 7 and aligned with the opening 8c of the abrasive bundle holding hole 8. As shown in FIGS. 3 and 4 , in this example, the abrasive bundle support surface 12 is an arcuate surface. The abrasive bundle support surface 12 is slightly set back from the opening 8c of the abrasive bundle holding hole 8. Alternatively, the abrasive bundle support surface 12 may not be set back from the opening 8c of the abrasive bundle holding hole 8 and may be continuous with the inner wall surface 8b of each abrasive bundle holding hole 8 without any step. The area of ​​the opening edge portion 8d may be determined as appropriate, and may be, for example, an area with a width of 0.5 mm surrounding the opening 8c of each abrasive bundle holding hole 8.

[0034] 4, the abrasive bundle support surface 12 intersects with a first imaginary plane S1, which includes the abrasive bundle holding hole rotation axis L and the hole axis L1 of the abrasive bundle holding hole 8, on the outer periphery of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 is provided in a region V at the opening edge 8d that is 120° or less on both sides of the hole axis L1 from the first imaginary plane S1. In other words, the region Y at the opening edge 8d of the abrasive bundle holding surface 7 where the abrasive bundle support surface 12 does not exist is located radially inward of each abrasive bundle holding hole 8 and includes an angular range of 60° on both sides of the hole axis L1 from the first imaginary plane S1.

[0035] In this example, the abrasive bundle support surface 12 has a shape symmetrical with respect to the first imaginary plane S1. The angle range W over which the abrasive bundle support surface 12 extends is 135° or more with respect to the hole axis L1. , 240° or less. Therefore, the abrasive bundle support surface 12 surrounds the opening 8c of the abrasive bundle holding hole 8 from the outer periphery. Here, it is more desirable that the angle range W over which the abrasive bundle support surface 12 extends is 145° or more and 203° or less around the hole axis L1.

[0036] In this example, the abrasive bundle support surface 12 is provided within an angular range of 155° around the hole axis L1. Therefore, in this example, if a plane including the hole axis L1 and perpendicular to the first imaginary plane S1 is defined as a second imaginary plane S2, the entire abrasive bundle support surface 12 is located on the outer periphery of the second imaginary plane S2. Also, as shown in FIG. 2 , the height H of the abrasive bundle support surface 12 protruding from the abrasive bundle holding surface 7 is 2 mm or more and 3 mm or less. Furthermore, in this example, the multiple wall portions 11 protruding from the abrasive bundle holding surface 7 and partially surrounding each abrasive bundle holding hole 8 are continuous in the circumferential direction. Therefore, the multiple wall portions 11 as a whole form an annular wall extending in the circumferential direction along the outer periphery of the abrasive bundle holding hole 8. The wall portion 11 may be divided into seven circumferential portions, each including a portion having an abrasive bundle support surface 12.

[0037] As shown in FIG. 1 , when the abrasive bundle 3 is held by the abrasive bundle holder 4 with its base end portion inserted into the abrasive bundle holding hole 8, the abrasive bundle 3 protrudes from the abrasive bundle holding surface 7 in the axial direction X. Furthermore, when the abrasive bundle 3 is held by the abrasive bundle holder 4 to form the polishing brush 1, the abrasive bundle support surface 12 of the wall portion 11 faces the abrasive bundle 3 from the outer periphery. Here, the abrasive bundle support surface 12 can come into contact with the abrasive bundle 3 when the abrasive bundle 3, held by the abrasive bundle holder 4 with its base end portion inserted into the abrasive bundle holding hole 8, bends in a direction away from the hole axis L1 during polishing of a workpiece. In other words, when the abrasive bundle 3 bends in a direction away from the hole axis L1 during polishing of a workpiece, the abrasive bundle support surface 12 comes into contact with the abrasive bundle 3. As a result, the abrasive bundle support surface 12 supports some of the linear abrasive materials 2 constituting the abrasive bundle 3 so that they do not bend too much.

[0038] A cylindrical portion 14 protruding from the abrasive bundle holding surface 7 is provided at the opening edge of the through hole 10 in the abrasive bundle holding surface 7. As shown in Figures 2 and 3, an internal thread 14a is provided on the inner peripheral wall surface of the cylindrical portion 14. The internal thread 14a is continuous with the internal thread 10a of the through hole 10.

[0039] As shown in FIG. 5, a plurality of grooves 17 extending radially from the center of the abrasive bundle holder are provided on the end face of the abrasive bundle holder opposite the abrasive bundle holding surface 7. The inner peripheral end of each groove 17 communicates with the through hole 10. The outer peripheral end of each groove 17 opens radially outward. Each groove 17 has a V-shaped circumferential cross section. In this example, the abrasive bundle holder has seven grooves 17. When viewed from the axial direction X, the hole axis L1 of each abrasive bundle holding hole 8 is located at the center of two grooves 17 adjacent to each other in the circumferential direction.

[0040] (Action and effect) Next, the effects of the abrasive brush 1 of this embodiment will be explained in comparison with a conventional abrasive brush 50. FIG. 7 is an explanatory diagram of the conventional abrasive brush 50. As shown in FIG. 7, the conventional abrasive brush 50 has a flat abrasive bundle holding surface 7 of the abrasive bundle holder, and does not have a wall portion 11 on the abrasive bundle holding surface 7. The other configuration is the same as the above-mentioned abrasive brush 1. Therefore, the same reference numerals are used for corresponding configurations, and their explanations will be omitted.

[0041] FIG. 8 is a graph showing the relationship between bristle length and the height difference of the linear abrasive 2 at the tip of the abrasive bundle 3 in a conventional abrasive brush 50. The horizontal axis of FIG. 8 is bristle length. Bristle length is the length dimension (mm) of the abrasive bundle 3 protruding from the abrasive bundle holding surface 7. Bristle length shortens due to wear during the polishing operation of polishing a workpiece. The horizontal axis of FIG. 8 shows the process by which the bristle length of the abrasive brush 50 shortens from 65 mm to 15 mm due to the polishing operation, from the left end to the right. The height difference on the vertical axis of FIG. 8 is the difference in length between the longest linear abrasive 2 and the shortest linear abrasive 2 at the tip of the abrasive bundle 3. The height difference is the difference in length between the longest linear abrasive 2 and the shortest linear abrasive 2 held in each of the multiple abrasive bundle holding holes 8. The measurements were taken for each of the abrasive bundles 3(1) to 3(7). Fig. 9 is a partially enlarged photograph of the tip of the abrasive bundle 3 in the conventional polishing brush 50 in a state where the bristles have worn down.

[0042] As shown in FIG. 8 , the inventors' investigations revealed that with a conventional abrasive brush 50, uneven wear occurs in each abrasive bundle 3 held in each of the multiple abrasive bundle holding holes 8 during a polishing process in which multiple workpieces are polished one after another. Specifically, as the bristles of the abrasive bundle 3 shorten due to wear caused by polishing the workpieces, the height difference between the linear abrasives 2 constituting the abrasive bundle 3 increases, resulting in noticeable uneven wear. Furthermore, for each abrasive bundle 3 held in each abrasive bundle holding hole 8 of the abrasive bundle holder 4, the wear of the linear abrasives 2 located at the outer end in the radial direction centered on the axis of the abrasive bundle holder 4 is less than the wear of the linear abrasives 2 located further inward. Therefore, as shown in FIG. 9 , for each abrasive bundle 3, the linear abrasives 2 located at the outer end (linear abrasives 2 adjacent to the measuring tape) are longer than the linear abrasives 2 located at the inner end (linear abrasives 2 away from the measuring tape).

[0043] The inventors have thoroughly investigated this phenomenon and have found that the reason why, as the bristle length of the abrasive bundle 3 becomes shorter, the linear abrasive 2 located at the outer end portion of each abrasive bundle 3 held in each abrasive bundle holding hole 8 of the abrasive bundle holder 4 wears less than the linear abrasive 2 located further inward is as follows.

[0044] That is, when a workpiece is polished, the abrasive bundle holder 4 is rotated around the rotation axis L, and the tip of each abrasive bundle 3 is brought into contact with the workpiece surface to be polished. The linear abrasives 2 located at the outermost end of each abrasive bundle 3 bend toward the periphery, allowing them to escape the force from the surface to be polished. In contrast, the linear abrasives 2 located at the innermost end are more likely to bend toward the periphery than the linear abrasives 2 located at the outermost end, due to the presence of many linear abrasives 2 on their outer periphery. Therefore, they are less likely to escape the force from the polishing surface. As the bristle length of the abrasive bundle 3 shortens during polishing, the rigidity of each linear abrasive 2 constituting the abrasive bundle 3 increases accordingly. As a result, the linear abrasives 2 located at the innermost end, which are less likely to escape the force from the polishing surface, are more likely to cut into the surface to be polished. As a result, the linear abrasives 2 located at the innermost end are more likely to wear out. On the other hand, even if the rigidity of the linear abrasive materials 2 at the end portion on the outer periphery side is increased, they can bend outward and release the force from the surface to be polished, compared to the linear abrasive materials 2 on the inner periphery side. As a result, the linear abrasive materials 2 located at the end portion on the outer periphery side wear less than the linear abrasive materials 2 located further inward.

[0045] To counter such uneven wear, in this embodiment, the abrasive bundle holding surface 7 of the abrasive bundle holder 4 is provided with multiple wall portions 11 that protrude from the opening edge portion 8d of each abrasive bundle holding hole 8 and partially surround the abrasive bundle holding hole 8. Each wall portion 11 has an abrasive bundle support surface 12 that is perpendicular to the abrasive bundle holding surface 7 and aligned with the opening 8c of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 intersects with a first imaginary plane S1 that includes the rotation axis L and the hole axis L1 of the abrasive bundle holding hole 8 on the outer periphery of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 also has a shape that is symmetrical with respect to the first imaginary plane S1 that includes the rotation axis L and the hole axis L1 of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 is provided within an angular range W of 155° (corresponding to the central angle of the sector) centered on the hole axis L1.

[0046] As a result, the abrasive bundle support surface 12 surrounds the abrasive bundle holding hole 8 from the outer periphery. Therefore, as shown in FIG. 1, in the abrasive brush 1 in which the base end portions of the abrasive bundles 3 are inserted into the abrasive bundle holding holes 8 of the abrasive bundle holder 4 and fixed to the abrasive bundle holder 4 with an adhesive, the abrasive bundle support surface 12 of the wall portion 11 faces the abrasive bundles 3 from the outer periphery. Therefore, when the abrasive bundle holder 4 is rotated around the rotation axis L and the tip portions of the abrasive bundles 3 are brought into contact with the surface of the workpiece to be polished, the abrasive bundle support surface 12 comes into contact with the linear abrasives 2 located at the outer periphery end portions of each abrasive bundle 3, and prevents the linear abrasives 2 from bending toward the outer periphery. Therefore, the amount of wear of the linear abrasives 2 located at the outer periphery end portions of each abrasive bundle 3 due to polishing of the workpiece is reduced by the amount of wear of the linear abrasives 2 located further inward. It is possible to approximate the amount of wear.

[0047] In this example, each wall portion 11 has an abrasive bundle support surface 12 that rises perpendicularly from the abrasive bundle holding surface 7 and is aligned with the opening 8c of the abrasive bundle holding hole 8, but the abrasive bundle support surface 12 may be inclined. That is, the abrasive bundle support surface 12 provided on each wall portion 11 may be in any of the following forms: (1) perpendicular to the abrasive bundle holding surface 7, (2) inclined toward the hole axis L1 as it moves away from the abrasive bundle holding surface 7, so that, when viewed from the axial direction X, the surface portion of the abrasive bundle support surface 12 farthest from the abrasive bundle holding surface 7 overlaps with the opening 8c of the abrasive bundle holding hole 8 or is located outside the opening 8c of the abrasive bundle holding hole 8, or (3) inclined away from the hole axis L1 as it moves away from the abrasive bundle holding surface 7.

[0048] In the above-described configuration (2) in which the abrasive bundle support surface 12 is inclined toward the hole axis L1, when the abrasive bundle 3 bends in a direction away from the hole axis L1 during polishing of the workpiece, the surface portion of the abrasive bundle support surface 12 farthest from the abrasive bundle holding surface 7 abuts against the abrasive bundle 3. As a result, the abrasive bundle support surface 12 prevents a portion of the linear abrasive 2 constituting the abrasive bundle 3 from bending excessively. In the above-described configuration (3) in which the abrasive bundle support surface 12 is inclined toward the side away from the hole axis L1 during polishing of the workpiece, when the abrasive bundle 3 bends in a direction away from the hole axis L1 during polishing of the workpiece, a portion of the linear abrasive 2 constituting the abrasive bundle 3 becomes aligned with the abrasive bundle support surface 12. Then, when the bending of the abrasive bundle 3 becomes greater than the inclination of the abrasive bundle support surface 12, the surface portion of the abrasive bundle support surface 12 farthest from the abrasive bundle holding surface 7 prevents a portion of the linear abrasive 2 constituting the abrasive bundle 3 from bending excessively.

[0049] In the above-described configuration (3) in which the abrasive bundle support surface 12 is inclined away from the hole axis L1, it is desirable to position the abrasive bundle support surface 12 closer to the opening 8c of the abrasive bundle holding hole 8 than when the abrasive bundle support surface 12 is perpendicular to the abrasive bundle holding surface 7. For example, the abrasive bundle support surface 12 may not be set back with respect to the opening 8c of the abrasive bundle holding hole 8, but may rise from the edge of the opening 8c of the abrasive bundle holding hole 8 on the abrasive bundle holding surface 7. The inclination of the abrasive bundle support surface 12 may be slight enough to prevent excessive bending of some of the linear abrasives 2 that make up the abrasive bundle 3.

[0050] FIG. 10 is a graph showing the relationship between bristle length and the height difference of the linear abrasive 2 at the tip of the abrasive bundle 3 in the abrasive brush 1 of this example. FIG. 11 is a partially enlarged photograph of the tip of the abrasive bundle 3 in the abrasive brush 1 of this example, in which the bristle length has worn down. As can be seen by comparing the graph in FIG. 10 with the graph in FIG. 8, the abrasive brush 1 of this example, compared to the conventional abrasive brush 50, has a reduced overall height difference of the linear abrasive 2 and a reduced variation in the height difference of each linear abrasive 2 as the bristle length shortens from 65 mm to 15 mm during the abrasive operation. Furthermore, even when the bristle length is shortened, the height difference of the linear abrasive 2 at the tip of the abrasive bundle 3 is kept small. This state is also shown in FIG. 11. Therefore, uneven wear is suppressed in the abrasive brush 1 of this example.

[0051] In this example, the abrasive bundle support surface 12 has a shape symmetrical with respect to a first imaginary plane S1 that includes the rotation axis L and the hole axis L1 of the abrasive bundle holding hole 8. Therefore, regardless of the direction in which the abrasive brush 1 rotates around the rotation axis L to polish the workpiece, it is possible to restrict the radially outward deflection and circumferential deflection of the linear abrasive 2 located at the end portion on the outer periphery of each abrasive bundle 3.

[0052] In this example, the height H of the abrasive bundle support surface 12 protruding from the abrasive bundle holding surface 7 is 2 mm or more and 3 mm or less. Therefore, even when the bristle length of the abrasive bundle 3 is shortened, it is possible to restrict the bending of the linear abrasives 2 located at the outer end portion of each abrasive bundle 3 held in each abrasive bundle holding hole 8 of the abrasive bundle holder 4 toward the outer periphery and in the circumferential direction. Therefore, the amount of wear of the linear abrasives 2 located at the outer end portion of each abrasive bundle 3 can be controlled by comparing the amount of wear of the linear abrasives 2 located further inward. Furthermore, if the height dimension H of the abrasive bundle support surface 12 is set to 3 mm or less, the abrasive bundles 3 held in the abrasive bundle holding holes 8 can be used up to a height close to that of the abrasive bundle holding surface 7, even when the wall portions 11 are provided on the abrasive bundle holding surface 7.

[0053] (Angle range of the abrasive bundle support surface) Here, the inventors have examined the angle range W over which the abrasive bundle support surface 12 extends. Fig. 12 is an explanatory diagram of the results of examination of the angle range W over which the abrasive bundle support surface 12 extends. In each example shown in Fig. 12, each wall portion 11 has an abrasive bundle support surface 12 that is perpendicular to the abrasive bundle holding surface 7 and aligned with the opening 8c of the abrasive bundle holding hole 8.

[0054] The diagram in the middle of Figure 12 is a plan view of the abrasive bundle holder 4 used to verify the angle range for extending the abrasive bundle support surface 12. The bottom column of Figure 12 shows the verification results. × indicates that there is no effect in suppressing uneven wear. △ indicates that there is a low effect in suppressing uneven wear. ◯ indicates that there is an effect in suppressing uneven wear. ◎ indicates that there is an excellent effect in suppressing uneven wear.

[0055] In the abrasive bundle holder 4(a) of FIG. 12, a wall portion 11 is provided in an annular shape along the outer periphery of the abrasive bundle holding surface 7. The abrasive bundle support surface 12 of the wall portion 11 facing the abrasive bundle holding hole 8 extends linearly from the radially outer side of the center of the abrasive bundle holding hole 8 to both sides in the circumferential direction. In other words, the abrasive bundle support surface 12 is V-shaped and does not have an arc shape along the opening 8c of the abrasive bundle holding hole 8. Therefore, the abrasive bundle support surface 12 does not extend over a predetermined angular range. The height dimension H of the abrasive bundle support surface 12 is 2 mm or more and 3 mm or less. The abrasive bundle support surface 12 has a shape symmetrical with respect to the first imaginary plane S1.

[0056] In the abrasive bundle holder 4(b) of FIG. 12, the wall portions 11 are provided radially outward of the abrasive bundle holding holes 8. The wall portions 11 located radially outward of each abrasive bundle holding hole 8 have abrasive bundle support surfaces 12 that face the abrasive bundle holding holes 8 and intersect with a first imaginary plane S1 on the outer periphery of the abrasive bundle holding holes 8. The abrasive bundle support surfaces 12 have a shape symmetrical with respect to the first imaginary plane S1. The abrasive bundle support surfaces 12 are also provided within an angular range W of 90° around the hole axis L1. The height dimension H of the abrasive bundle support surfaces 12 is 2 mm or more and 3 mm or less. The abrasive bundle support surfaces 12 have a shape symmetrical with respect to the first imaginary plane S1. In this example, the wall portions 11 are not continuous in the circumferential direction, and gaps are present between adjacent wall portions 11 in the circumferential direction.

[0057] The abrasive bundle holder 4(c) in Figure 12 is the abrasive bundle holder 4 of the above embodiment. The wall portion 11 is continuous in the circumferential direction. The abrasive bundle support surface 12 intersects with the first imaginary plane S1 on the outer periphery of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 has a shape symmetrical with respect to the first imaginary plane S1. The abrasive bundle support surface 12 is provided within an angular range W of 155° around the hole axis L1. The height dimension H of the abrasive bundle support surface 12 is 2 mm or more and 3 mm or less. The entire abrasive bundle support surface 12 is located on the outer periphery side of the second imaginary plane S2.

[0058] In the abrasive bundle holder 4(d) of FIG. 12, the wall portion 11 is continuous in the circumferential direction. The abrasive bundle support surface 12 intersects with the first imaginary plane S1 on the outer periphery of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 has a shape symmetrical with respect to the first imaginary plane S1. The abrasive bundle support surface 12 is provided within an angular range W of 203° around the hole axis L1. The height dimension H of the abrasive bundle support surface 12 is 2 mm or more and 3 mm or less. In this example, the entire region Y where the abrasive bundle support surface 12 is not present is located on the inner periphery side of the second imaginary plane S2.

[0059] In the abrasive bundle holder 4(e) of Figure 12, the wall portion 11 is continuous in the circumferential direction. The abrasive bundle support surface 12 intersects with the first imaginary plane S1 on the outer periphery side of the abrasive bundle holding hole 8. The abrasive bundle support surface 12 has a shape symmetrical with respect to the first imaginary plane S1. The abrasive bundle support surface 12 is provided within an angular range W of 309° around the hole axis L1. The height dimension H of the abrasive bundle support surface 12 is 2m In this example, the entire area Y where the abrasive bundle support surface 12 does not exist is located on the inner circumferential side with respect to the second imaginary plane S2.

[0060] FIG. 13 is a partially enlarged photograph of the tip of the abrasive bundle 3 in a state where the bristles have worn in an abrasive brush using an abrasive bundle holder 4(a) in which the wall portion 11 is annularly provided on the outer periphery of the abrasive bundle holding surface 7. As shown in FIG. 13, when the bristles of the abrasive bundle holder 4(a) are shortened, the height difference of the linear abrasive 2 at the tip of the abrasive bundle 3 remains, similar to that of the conventional abrasive brush 50. Therefore, uneven wear is not suppressed in the abrasive bundle holder 4(a) of FIG. 12. Here, in the abrasive bundle holder 4(a), the abrasive bundle support surface 12 is not aligned with the opening 8c of the abrasive bundle holding hole 8, so the radial outward deflection and circumferential deflection of the linear abrasive 2 located at the outer end of each abrasive bundle 3 cannot be restricted. Therefore, it is presumed that uneven wear is not suppressed.

[0061] It was confirmed that the abrasive bundle holder 4(b) in FIG. 12 is less effective in suppressing uneven wear. It is presumed that the angle range W in which the abrasive bundle support surface 12 is formed is narrow in the abrasive bundle holder 4(b) in FIG. 12, and therefore uneven wear is not suppressed. It was also confirmed that the abrasive bundle holder 4(e) in FIG. 12 is less effective in suppressing uneven wear. According to the inventor's verification, when the abrasive bundle support surface 12 is provided within an angle range W exceeding 240° around the hole axis L1, the wall portion 11 surrounds nearly the entire circumference of the abrasive bundle holding hole 8 (the angle range W approaches 360°). Therefore, uneven wear occurs in each abrasive bundle 3 in the same way as when the wall portion 11 is not provided.

[0062] It has been confirmed that uneven wear is suppressed in the abrasive bundle holder 4(c) of Fig. 12 and the abrasive bundle holder 4(d) of Fig. 12. According to the inventor's verification, the effect of the abrasive bundle holder 4(c) in suppressing uneven wear is greater than that of the abrasive bundle holder 4(d) of Fig. 12.

[0063] Through these verifications, it has been determined that the angle range W over which the abrasive bundle support surface 12 of the abrasive bundle holder 4 extends is preferably 135° or more and 240° or less, centered on the hole axis L1. More preferably, the angle range W over which the abrasive bundle support surface 12 of the abrasive bundle holder 4 extends can be set to 145° or more and 203° or less, centered on the hole axis L1.

[0064] In the above example, it is described that a wall portion 11 is provided protruding from the abrasive bundle holding surface 7 and that the abrasive bundle support surface 12 is provided on the wall portion 11, but an abrasive bundle support surface 12 similar to the above can be formed by providing a recess in the abrasive bundle holding surface 7. For example, an abrasive bundle support surface 12 similar to the above can be provided by forming a recess recessed in the axial direction X in the region Y where the abrasive bundle support surface 12 is not present at the opening edge portion 8d of the abrasive bundle holding surface 7.

[0065] (Variation) (Variations 1 to 3) Fig. 14 is an explanatory diagram of an abrasive bundle holder 4 of Modification 1. Fig. 15 is an explanatory diagram of an abrasive bundle holder 4 of Modification 2. Fig. 16 is an explanatory diagram of an abrasive bundle holder 4 of Modification 3. In Figs. 14 to 16, the abrasive bundle support surface 12 is indicated by a thick line in the front view of the abrasive bundle holder 4.

[0066] The abrasive bundle holders 4 of Modifications 1 to 3 are used with abrasive brushes 1 in which the direction of rotation when polishing a workpiece is set to one direction around the rotation axis L. The abrasive bundle holders 4 of Modifications 1 to 3 are configured as abrasive brushes 1 by fixing abrasive bundles 3 in each abrasive bundle holding hole 8 of the abrasive bundle holder 4. The abrasive bundle 3 is a bundle of multiple linear abrasives 2, and its base end portion is inserted into the abrasive bundle holding hole 8. The abrasive bundle 3 is held in the abrasive bundle holder 4 by an adhesive (resin member 5) that hardens within the abrasive bundle holding hole 8.

[0067] In the abrasive bundle holders 4 of Modifications 1 to 3, the abrasive bundle support surface 12 intersects with the first imaginary plane S1 on the outer periphery of the abrasive bundle holding hole 8. In the abrasive bundle holders 4 of Modifications 1 to 3, the abrasive bundle support surface 12 does not have a shape that is symmetrical with respect to the first imaginary plane S1. That is, in the abrasive bundle holders 4 of Modifications 1 to 3, the circumferential center of the abrasive bundle support surface 12 is offset from the first imaginary plane S1 around the hole axis L1 of the abrasive bundle holding hole 8.

[0068] Here, the direction in which the circumferential center of the abrasive bundle support surface 12 deviates from the first imaginary plane S1 is the rear of the rotation direction in which the abrasive brush 1 (abrasive bundle holder 4) rotates when polishing a workpiece. In the example shown in FIGS. 14 to 16, the abrasive brush 1 (abrasive bundle holder 4) rotates in a first rotation direction R1 (CCW) indicated by the thick arrow when polishing a workpiece. Therefore, the circumferential center of the abrasive bundle support surface 12 deviates in a second rotation direction R2 (CW) opposite to the first rotation direction R1. Although not shown in the drawings, when the abrasive brush 1 (abrasive bundle holder 4) rotates in the second rotation direction R2 (CW) when polishing a workpiece, the circumferential center of the abrasive bundle support surface 12 is positioned so as to deviate in the first rotation direction R1 (CCW) opposite to the second rotation direction R2.

[0069] In Modification 1 shown in Figure 14, the abrasive bundle support surface 12 is provided in an area V of 120° or less on one side and the other side of the opening edge 8d of the abrasive bundle holding hole 8 around the hole axis L1 from the first imaginary plane S1. The angular range W over which the abrasive bundle support surface 12 extends is 135° or more and 240° or less around the hole axis L1. The circumferential center of the abrasive bundle support surface 12 is shifted in the second rotational direction R2 (CW). The abrasive bundle holder 4 in Figure 14 is an example of Modification 1, and the abrasive bundle support surface 12 is provided in the angular range W of 135°.

[0070] In Modification 2 shown in FIG. 15 , the abrasive bundle support surface 12 is provided at the opening edge 8d of the abrasive bundle holding hole 8 in an area of ​​120° or less on one side and the other side around the hole axis L1 from the first imaginary plane S1. The circumferential center of the abrasive bundle support surface 12 is shifted in the second rotational direction R2 (CW). In Modification 2, when a plane including the hole axis L1 and perpendicular to the first imaginary plane S1 is defined as a second imaginary plane S2, the entire abrasive bundle support surface 12 is located on the outer periphery of the second imaginary plane S2. Therefore, in this example, the angular range W over which the abrasive bundle support surface 12 extends is 135° or more and 180° or less around the hole axis L1. The abrasive bundle holder 4 in FIG. 15 is an example of Modification 2, and the abrasive bundle support surface 12 is provided within an angular range W of 135°.

[0071] In Modification 3 shown in FIG. 16 , the abrasive bundle support surface 12 is provided at the opening edge 8d of each abrasive bundle holding hole 8 in an area of ​​120° or less on one side and the other side around the hole axis L1 from the first imaginary plane S1. The circumferential center of the abrasive bundle support surface 12 is shifted in the second rotational direction R2 (CW). In Modification 3, when a second imaginary plane S2 is defined as a plane that includes the hole axis L1 and is perpendicular to the first imaginary plane S1, the entire area Y at the opening edge 8d of each abrasive bundle holding hole 8 where the abrasive bundle support surface 12 is not present is located on the inner circumferential side of the second imaginary plane S2. Therefore, in this example, the angular range W over which the abrasive bundle support surface 12 extends is 180° or more and 240° or less around the hole axis L1. The abrasive bundle holder 4 in FIG. 16 is an example of Modification 3, and the abrasive bundle support surface 12 is provided within an angular range W of 210°.

[0072] (Action and effect) In the abrasive bundle holders 4 of Modifications 1 to 3, when a workpiece is polished, the polishing brush 1 (abrasive bundle holder 4) rotates in a first rotation direction R1 (CCW) indicated by the arrow. The circumferential center of the abrasive bundle support surface 12 is shifted to a second rotation direction R2 (CW) opposite to the first rotation direction R1. In the abrasive bundle holders 4 of Modifications 1 to 3 as well, when the tip portion of each abrasive bundle 3 is brought into contact with the surface of the workpiece to be polished while the abrasive bundle holder 4 is rotated around the rotation axis L, the abrasive bundle support surface 12 can prevent the linear abrasive 2 located at the end portion on the outer periphery of each abrasive bundle 3 from bending outward. Furthermore, in the abrasive bundle holders 4 of Modifications 1 to 3, the abrasive bundle support surface 12 prevents the linear abrasive 2 located at the outer periphery of each abrasive bundle 3 from bending outward. The circumferential center of the support surface 12 is shifted from the first imaginary plane S1 in the second rotation direction R2. Therefore, the abrasive bundle support surface 12 can prevent the linear abrasives 2 located at the outer peripheral end portion of each abrasive bundle 3 from bending in the second rotation direction R2, which is opposite to the first rotation direction R1 in which the abrasive brush 1 (abrasive bundle holder 4) rotates. Therefore, when the workpiece is polished, the amount of wear of the linear abrasives 2 located at the outer peripheral end portion of each abrasive bundle 3 can be made closer to the amount of wear of the linear abrasives 2 located further inward.

[0073] (Variation 4) FIG. 17 is an explanatory diagram of an abrasive bundle holder 4 according to Modification 4. The abrasive bundle holder 4 has an abrasive bundle holding surface 7 perpendicular to the rotation axis L and a plurality of abrasive bundle holding holes 8 formed in the abrasive bundle holding surface 7. The plurality of abrasive bundle holding holes 8 are arranged in a ring shape around the rotation axis L. A wall portion 11 protrudes from the abrasive bundle holding surface 7 at the opening edge 8d of each abrasive bundle holding hole 8 and partially surrounds the abrasive bundle holding hole 8. In the radial direction centered on the rotation axis L, if the side where the rotation axis L is located is defined as the inner circumferential side and the opposite side is defined as the outer circumferential side, each wall portion 11 is located on the outer circumferential side of an imaginary cylindrical surface S3 connecting the hole axes L1 of the abrasive bundle holding holes 8. Each wall portion 11 has an abrasive bundle support surface 12 that is perpendicular to the abrasive bundle holding surface 7 and aligned with the opening 8c of the abrasive bundle holding hole 8. The angle range W over which the abrasive bundle support surface 12 extends is equal to or greater than 135° and equal to or less than 203° about the hole axis L1.

[0074] The abrasive bundle holder 4 of this example is made into a polishing brush 1 by fixing abrasive bundles 3 in each abrasive bundle holding hole 8 of the abrasive bundle holder 4. The abrasive bundle 3 is made by bundling a plurality of linear abrasives 2, and the base end portion of the abrasive bundle 3 is inserted into the abrasive bundle holding hole 8. The abrasive bundle 3 is held in the abrasive bundle holder 4 by an adhesive (resin member 5) that hardens inside the abrasive bundle holding hole 8.

[0075] Here, the abrasive bundle holder 4 of this example may have an abrasive bundle support surface 12 that is symmetrical with respect to the first imaginary plane S1. Furthermore, when the abrasive bundle holder 4 of this example is rotated in a predetermined rotational direction when polishing a workpiece, the circumferential center of the abrasive bundle support surface 12 may be shifted rearward in the rotational direction. Specifically, when the abrasive bundle holder 4 is used in an abrasive brush 1 that is rotated in a first rotational direction R1, the circumferential center of the abrasive bundle support surface 12 may be shifted in a second rotational direction R2 around the hole axis L1 of the abrasive bundle holding hole 8. Furthermore, when the abrasive bundle holder 4 is used in an abrasive brush 1 that is rotated in the second rotational direction R2, the circumferential center of the abrasive bundle support surface 12 may be shifted in the first rotational direction R1 around the hole axis L1 of the abrasive bundle holding hole 8. The abrasive bundle holder 4 in FIG. 17 is an example of Modification 4, and the abrasive bundle support surface 12 is provided in an angle range W of less than 180°.

[0076] In the abrasive bundle holder 4 of this embodiment, the abrasive bundle holding hole 8 may have a shape that is two-fold rotationally symmetric about the hole axis L1. For example, the abrasive bundle holding hole 8 may be rectangular, elliptical, or oblong. In the abrasive bundle holder 4 of this embodiment, the abrasive bundle holding hole 8 may have a shape that is three-fold rotationally symmetric about the hole axis L1. For example, the abrasive bundle holding hole 8 may be an equilateral triangle. Furthermore, the abrasive bundle holding hole 8 may have a shape that is four-fold or more rotationally symmetric about the hole axis L1. In this case, the abrasive bundle holding hole 8 may be a square, regular pentagon, regular hexagon, or a regular polygon with more than two sides. Furthermore, each corner of these regular polygons may be cut out in the same shape toward the hole axis L1, or each corner of the regular polygon may be curved. Alternatively, the abrasive bundle holding hole 8 may have a polygonal or approximately polygonal shape with the hole axis L1 as the intersection of the diagonals. In these cases, the abrasive bundle support surface 12 is not an arc surface, but rather comprises a combination of flat and curved portions extending along the sides of the opening 8c of the abrasive bundle holding hole 8, and bent portions that bend along the corners and curved portions of each shape.

[0077] (Action and effect) In the abrasive bundle holder 4 of this example, when the tip portion of each abrasive bundle 3 is brought into contact with the surface of the workpiece to be polished while the abrasive bundle holder 4 is rotated around the rotation axis L, The contact surface 12 can prevent the linear abrasives 2 located at the outer peripheral end portion of each abrasive bundle 3 from bending outward (radially outward and circumferentially). Therefore, the amount of wear of the linear abrasives 2 located at the outer peripheral end portion of each abrasive bundle 3 due to polishing of the workpiece can be made to approach the amount of wear of the linear abrasives 2 located further inward.

[0078] (summary) The present invention can take the following forms.

[0079] (1) The abrasive material holding member has an abrasive material bundle holding surface that is perpendicular to the rotation axis and a plurality of abrasive material bundle holding holes that are provided in the abrasive material bundle holding surface, The plurality of abrasive bundle holding holes are circular and arranged in an annular shape around the rotation shaft, a wall portion protruding from the abrasive bundle holding surface and partially surrounding the abrasive bundle holding hole is provided at an opening edge of each abrasive bundle holding hole; each wall portion has an abrasive bundle support surface rising from the abrasive bundle holding surface and aligned with the opening of the abrasive bundle holding hole; In a radial direction centered on the rotation axis, when the side where the rotation axis is located is defined as an inner peripheral side and the opposite side is defined as an outer peripheral side, the abrasive bundle support surface intersects with a first imaginary plane including the rotation axis and a hole axis of the abrasive bundle holding hole on the outer peripheral side of the abrasive bundle holding hole, An abrasive bundle holder, characterized in that the angle range over which the abrasive bundle support surface extends is an angle range of 135° or more and 240° or less, centered on the hole axis.

[0080] (2) When a plane including the hole axis and perpendicular to the first imaginary plane is defined as a second imaginary plane, The abrasive bundle holder according to (1) above, wherein the entire abrasive bundle support surface is located on the outer periphery side of the second imaginary plane.

[0081] (3) When a plane including the hole axis and perpendicular to the first imaginary plane is defined as a second imaginary plane, An abrasive bundle holder as described in (1) or (2) above, characterized in that at the opening edge of each abrasive bundle holding hole, the area where the abrasive bundle support surface does not exist is entirely located on the inner side of the second imaginary plane.

[0082] (4) An abrasive bundle holder as described in any one of (1) to (3) above, characterized in that the abrasive bundle support surface is provided in an area at the opening edge portion that is 120° or less from the first imaginary plane to one side and the other side around the hole axis.

[0083] (5) The abrasive bundle holder according to any one of (1) to (4) above, wherein the abrasive bundle support surface has a shape symmetrical with respect to the first imaginary plane.

[0084] (6) An abrasive bundle holder as described in any one of (1) to (5) above, characterized in that the height dimension of the abrasive bundle support surface protruding from the abrasive bundle holding surface is 2 mm or more and 3 mm or less.

[0085] (7) The contour shape of the abrasive bundle holding surface is a regular polygon, The abrasive bundle holding surface has the same number of abrasive bundle holding holes as the corners of the contour shape of the abrasive bundle holding surface. is established, Each abrasive bundle holding hole is provided at an inside corner of each corner of the contour shape of the abrasive bundle holding surface, The abrasive bundle holder according to any one of (1) to (6) above, wherein the plurality of wall portions are continuous in the circumferential direction around the rotation axis.

[0086] (8) having a through hole, An abrasive bundle holder as described in any one of (1) to (7) above, characterized in that the through hole is arranged coaxially with the rotation axis on the inner circumferential side of the plurality of abrasive bundle holding holes.

[0087] (9) The abrasive material holding member has an abrasive material bundle holding surface that is perpendicular to the rotation axis and a plurality of abrasive material bundle holding holes that are provided in the abrasive material bundle holding surface, The plurality of abrasive bundle holding holes are arranged in an annular shape around the rotation shaft, a wall portion protruding from the abrasive bundle holding surface and partially surrounding the abrasive bundle holding hole is provided at an opening edge of each abrasive bundle holding hole; In a radial direction centered on the rotation axis, when the side where the rotation axis is located is defined as an inner peripheral side and the opposite side is defined as an outer peripheral side, each wall portion is located on the outer peripheral side of an imaginary cylindrical surface connecting the axis lines of each abrasive bundle holding hole, and is provided with an abrasive bundle support surface that rises from the abrasive bundle holding surface and follows the opening of the abrasive bundle holding hole, An abrasive bundle holder, characterized in that the angle range over which the abrasive bundle support surface extends is 135° or more and 203° or less, centered on the hole axis.

[0088] (10) An abrasive bundle holder according to any one of (1) to (9) above, characterized in that the abrasive bundle support surface is arranged within an angle range of 145° or more and 203° or less from the center of the hole axis.

[0089] (11) An abrasive bundle holder according to any one of (1) to (10) above, characterized in that the abrasive bundle support surface is provided at an angle range of 155° or more and 203° or less from the center of the hole axis.

[0090] (12) The abrasive bundle holder according to any one of (1) to (11) above, wherein the abrasive bundle support surface rises vertically from the abrasive bundle holding surface.

[0091] (13) An abrasive bundle holder as described in any one of (1) to (11) above, characterized in that the abrasive bundle support surface inclines toward the hole axis as it moves away from the abrasive bundle holding surface, and when viewed from the axial direction, the surface portion of the abrasive bundle support surface farthest from the abrasive bundle holding surface overlaps with the opening of the abrasive bundle holding hole or is located outside the opening of the abrasive bundle holding hole.

[0092] (14) The abrasive bundle holder according to any one of (1) to (13) above, a plurality of abrasive bundles; Each abrasive bundle is formed by bundling a plurality of linear abrasives, and a base end portion of each abrasive bundle is inserted into the abrasive bundle holding hole and is held by the abrasive bundle holder by an adhesive that hardens within the abrasive bundle holding hole; The abrasive bundle holder is rotated around the rotation axis to polish the workpiece. Abrasive brush. [Explanation of symbols]

[0093] 1...abrasive brush, 2...linear abrasive, 3...abrasive bundle, 4...abrasive bundle holder, 5...resin member, 7...abrasive bundle holding surface, 7a...corner portion, 8...abrasive bundle holding hole, 8a...bottom surface, 8b...inner peripheral wall surface, 8c...opening, 8d...opening edge portion, 10...through hole, 10a...female thread, 11...wall portion, 12...abrasive bundle support surface, 14...cylindrical portion, 14a...female thread, 17...groove, 50...conventional abrasive brush, H...height dimension, L...rotation axis, L1...hole axis line, R1...first rotation direction, R2...second rotation direction, S1...first imaginary plane, S2...second imaginary plane, S3...imaginary cylindrical surface, V...area, W...angle range, X...axial direction, Y...area

Claims

1. The abrasive material holding member has an abrasive material bundle holding surface that is perpendicular to the rotation axis and a plurality of abrasive material bundle holding holes that are provided on the abrasive material bundle holding surface, The plurality of abrasive bundle holding holes are circular and arranged in an annular shape around the rotation shaft, a wall portion protruding from the abrasive bundle holding surface and partially surrounding the abrasive bundle holding hole is provided at an opening edge of each abrasive bundle holding hole; each wall portion has an abrasive bundle support surface rising from the abrasive bundle holding surface and aligned with the opening of the abrasive bundle holding hole; In a radial direction centered on the rotation axis, when the side where the rotation axis is located is defined as an inner peripheral side and the opposite side is defined as an outer peripheral side, the abrasive bundle support surface intersects with a first imaginary plane including the rotation axis and a hole axis of the abrasive bundle holding hole on the outer peripheral side of the abrasive bundle holding hole, An abrasive bundle holder, characterized in that the angle range over which the abrasive bundle support surface extends is an angle range of 135° or more and 240° or less, centered on the hole axis.

2. When a plane including the hole axis and perpendicular to the first imaginary plane is defined as a second imaginary plane, (1) The entire abrasive bundle support surface is located on the outer circumferential side of the second imaginary plane, or (2) An abrasive bundle holder as described in claim 1, characterized in that at the opening edge of each abrasive bundle holding hole, the area where the abrasive bundle support surface does not exist is entirely located on the inner side of the second imaginary plane.

3. 3. The abrasive bundle holder according to claim 2, wherein the abrasive bundle support surface is provided in an area of ​​the opening edge portion that is 120° or less on one side and the other side of the hole axis from the first imaginary plane.

4. 4. The abrasive bundle holder according to claim 3, wherein the abrasive bundle support surface has a shape symmetrical with respect to the first imaginary plane.

5. 5. The abrasive bundle holder according to claim 4, wherein the height dimension of the abrasive bundle support surface protruding from the abrasive bundle holding surface is 2 mm or more and 3 mm or less.

6. The contour shape of the abrasive bundle holding surface is a regular polygon, the abrasive bundle holding surface is provided with the abrasive bundle holding holes, the number of which is the same as the number of corners of the contour shape of the abrasive bundle holding surface; Each abrasive bundle holding hole is provided at an inside corner of each corner of the contour shape of the abrasive bundle holding surface, 6. The abrasive bundle holder according to claim 5, wherein the plurality of wall portions are continuous in the circumferential direction around the rotation axis.

7. having a through hole, 7. The abrasive bundle holder according to claim 6, wherein the through-hole is provided coaxially with the rotation axis on the inner circumferential side of the plurality of abrasive bundle holding holes.

8. The abrasive material holding member has an abrasive material bundle holding surface that is perpendicular to the rotation axis and a plurality of abrasive material bundle holding holes that are provided on the abrasive material bundle holding surface, The plurality of abrasive bundle holding holes are arranged in an annular shape around the rotation shaft, a wall portion protruding from the abrasive bundle holding surface and partially surrounding the abrasive bundle holding hole is provided at an opening edge of each abrasive bundle holding hole; In the radial direction centered on the rotation axis, when the side where the rotation axis is located is the inner peripheral side and the opposite side is the outer peripheral side, each wall portion is formed by the imaginary cylindrical surface connecting the axis lines of each abrasive bundle holding hole. an abrasive bundle support surface located on the outer periphery, rising from the abrasive bundle holding surface and extending along the opening of the abrasive bundle holding hole; An abrasive bundle holder, characterized in that the angle range over which the abrasive bundle support surface extends is 135° or more and 203° or less, centered on the hole axis.

9. 9. An abrasive bundle holder according to claim 1, wherein the abrasive bundle support surface is provided at an angle ranging from 145° to 203° around the hole axis.

10. 10. The abrasive bundle holder according to claim 9, wherein the abrasive bundle support surface is provided at an angle ranging from 155° to 203° around the hole axis.

11. An abrasive bundle holder according to any one of claims 1 to 8; a plurality of abrasive bundles; Each abrasive bundle is formed by bundling a plurality of linear abrasives, and a base end portion of each abrasive bundle is inserted into the abrasive bundle holding hole and is held by the abrasive bundle holder by an adhesive that hardens within the abrasive bundle holding hole; An abrasive brush characterized in that it is rotated around the rotation axis of the abrasive bundle holder to abrade a workpiece.

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