Abrasive brush and brush holder

Abstract

[Problem] To provide a grinding brush that can change the extension direction of the brush in several directions, and can accurately reproduce the extension direction before the change even when the extension direction is changed. [Solution] The grinding brush (1) includes a brush holder (2) and a brush (3). The brush holder (2) has a handle (5) and a brush holding member (6). The base end of the handle is connected to the tool holder of a lathe, and the brush holding member is supported on the front end of the handle (5). The brush (3) is detachably held in the brush holding member (6) by a brush holding hole (7) provided on the annular outer peripheral surface (33) of the brush holding member (6) surrounding the Y-axis orthogonal to the axis of the handle (5), and protrudes from the brush holding member (6) in the radial direction outward. The brush holder (2) is a positioning mechanism (60) that positions the brush holder (6) at a plurality of rotation angle positions, and a fixing mechanism (61) that fixes the positioned brush holder (6) to the handle (5).

Description

Abrasive brushes and brush holders The present invention relates to a grinding brush for grinding a rotating workpiece. Moreover, the present invention also relates to a brush retaining seat for keeping a brush in the grinding brush. Patent document 1 describes an abrasive brush for grinding a rotating workpiece. The abrasive brush in the same document comprises a rod-shaped component and a brush held by the rod-shaped component. The rod-shaped component has a brush holding hole for holding the brush at the front end. The brush holding hole is recessed rearward in a direction intersecting the axis of the rod-shaped component. The brush comprises an abrasive bundle consisting of a plurality of linear abrasives and an abrasive holding seat for holding one end of the abrasive bundle. The brush is held in the rod-shaped component with the abrasive bundle holding seat inserted into the brush holding hole. When the brush is held in the rod-shaped component, the abrasive bundle extends forward toward the outer peripheral side of the rod-shaped component. The inclination angle at which the extension direction of the abrasive bundle intersects the axis of the rod-shaped component is less than 45°. The polishing brush described in the same document is used, for example, to polish the inner circumference of a pipe. When polishing the inner circumference of a pipe, the polishing brush is connected to the head of a machining center or machine tool, with the axis of the rod-shaped member parallel to the pipe axis. In this position, the polishing brush is inserted into the inner side of the pipe and polishes the inner circumference of the pipe while rotating around the pipe axis. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent No. 6810435 [Problems to be solved by the invention] There is a demand for polishing a variety of parts with a single polishing brush. However, polishing a variety of parts requires adjusting the contact angle between the brush and the target area for each part. Conventionally, this adjustment involves attaching the polishing brush to the head via an angle adjustment fixture. When the polishing brush is connected to the head with a clamp to adjust the brush angle, the reproducibility of the brush angle is low. Therefore, once the clamp between the polishing brush and the head is removed, the brush angle cannot be accurately reproduced when the same part is polished later, and there is a possibility that the polishing accuracy cannot be maintained. [Solution] In view of the above problems, the present invention aims to provide an abrasive brush capable of changing the extension direction of the brush in a plurality of reciprocating directions, and even if the extension direction is changed, the extension direction of the brush can be correctly returned to the extension direction before the change. Furthermore, a brush holder is provided, which can also return the extension direction of the brush to the extension direction before the change even if the extension direction is changed. To solve the above-mentioned problems, the present invention is characterized in that, when three axes orthogonal to each other are defined as an X-axis, a Y-axis, and a Z-axis, and a direction along the X-axis is defined as an X-axis direction, a direction along the Y-axis is defined as a Y-axis direction, and a direction along the Z-axis is defined as a Z-axis direction, the present invention comprises: a brush holder having a handle having an axis aligned with the X-axis; a brush holding member supported by a front end portion of the handle; a brush holding hole provided on an annular outer peripheral surface of the brush holding member around a Y-axis orthogonal to the axis; a positioning mechanism for positioning the brush holding member at a first rotational angle position around the Y-axis or a second rotational angle position different from the first rotational angle position; and a fixing mechanism for fixing the positioned brush holding member to the handle; and a brush detachably held in the brush holding hole, protruding radially outward from the brush holding member, and extending outward from the handle when viewed in the Y-axis direction. According to the present invention, the brush extends radially outward from the brush holding member with the Y-axis as the center. The brush holding member is supported by the front end portion of the handle extending in the X-axis direction, and is fixed to the handle when positioned at the first rotation angle position or the second rotation angle position around the Y-axis. Therefore, the extension (extension setting) direction of the brush can be changed when the brush holding member is positioned at the first rotation angle position and fixed to the handle, and when the brush holding member is positioned at the second rotation angle position and fixed to the handle. Therefore, even when the handle is connected to the machine tool without using a clamp for angle adjustment, the extension direction of the brush can be changed. In addition, the brush holding member is positioned at the first rotation angle position and the second rotation angle position, respectively, so even when the extension direction is changed, the extension direction of the brush can be correctly returned to the extension direction before the change. In the present invention, the brush holding member may have a regular polygonal outline when viewed from the Y-axis direction, and the handle may include a positioning surface as the positioning mechanism, which is capable of contacting a portion of the annular outer peripheral surface of the brush holding member from the radially outer side thereof with a portion of the outer peripheral surface extending linearly in the circumferential direction. This facilitates positioning of the brush holding member. In the present invention, the brush holding component may have a regular polygonal outline when viewed from the Y-axis direction, and the handle may serve as the positioning mechanism and include a first positioning surface and a second positioning surface, which are capable of contacting two linearly extending circumferential outer surface portions of the annular outer surface of the brush holding component from the radially outer side. This facilitates positioning of the brush holding component. Furthermore, this prevents or suppresses circumferential shaking of the brush holding component after positioning. In the present invention, the brush-retaining component may have a regular polygonal outline when viewed from the Y-axis direction, and the brush-retaining hole may be recessed radially inward. The brush-retaining component may include a first brush-retaining hole and a second brush-retaining hole. The first brush-retaining hole is provided on a portion of the annular outer surface extending linearly in the circumferential direction, while the second brush-retaining hole is provided across a ridgeline between two adjacent portions of the annular outer surface in the circumferential direction. The brush may be selectively retained by either the first brush-retaining hole or the second brush-retaining hole. This allows the brush to be retained in the first brush-retaining hole and the second brush-retaining hole to change its direction of extension. Therefore, by combining the brush-retaining component with two abrasive-retaining holes and the brush-retaining component positioned and fixed at either the first rotational angle position or the second rotational angle position, the ability to distinguish the direction in which the brush is extended can be improved. In the present invention, the Z-axis passes through the intersection of the X-axis and the Y-axis, and when the brush holding member is positioned at the first rotation angle and fixed to the handle, the brush extends in a first direction outward in the radial direction toward a side closer to the X-axis than the Z-axis. When the brush holding member is positioned at the second rotation angle and fixed to the handle, the brush extends in a second direction outward in the radial direction toward a side closer to the X-axis than the Z-axis. In this manner, the extension direction of the brush can be changed between the first direction toward one side of the X-axis and the second direction toward the other side of the X-axis. In the present invention, the Z-axis passes through the intersection of the X-axis and the Y-axis, and when the brush holding member is positioned at the first rotation angle and fixed to the handle, the brush extends in a first direction outward in the radial direction toward a side closer to the Z-axis than the X-axis. When the brush holding member is positioned at the second rotation angle and fixed to the handle, the brush extends in a second direction outward in the radial direction toward a side closer to the Z-axis than the X-axis. In this manner, the extension direction of the brush can be changed between the first direction toward one side of the Z-axis and the second direction toward the other side of the Z-axis. In the present invention, the brush may include an abrasive bundle consisting of a plurality of linear abrasives and an abrasive bundle holder that holds one end portion of the abrasive bundle; and the abrasive bundle holder may be inserted into the brush holding hole. In the present invention, there can be: a limiting component fixed on the aforementioned handle to limit the expansion of the aforementioned brush, the aforementioned brush has an abrasive bundle composed of a plurality of linear abrasives and an abrasive bundle holding seat holding one end portion of the aforementioned abrasive bundle; the aforementioned abrasive bundle holding seat is inserted into the aforementioned brush holding hole; the aforementioned limiting component has a relative portion, which is a portion between the other end portion of the aforementioned abrasive bundle and the aforementioned brush holding component, and is opposite to each other with a gap separated from the circumferential direction around the aforementioned Y-axis. In the present invention, there can be: a limiting component fixed on the aforementioned brush holding component to limit the expansion of the aforementioned brush; the aforementioned brush has an abrasive bundle composed of a plurality of linear abrasives and an abrasive bundle holding seat holding one end portion of the aforementioned abrasive bundle; the aforementioned abrasive bundle holding seat is inserted into the aforementioned brush holding hole; the aforementioned limiting component is a portion between the other end portion of the aforementioned abrasive bundle and the aforementioned brush holding component, and is opposite to each other with a gap separated from the circumferential direction around the aforementioned Y-axis. Next, the present invention is a brush holder for holding a brush. When three mutually orthogonal axes are set as the X-axis, Y-axis, and Z-axis, and the direction along the X-axis is set as the X-axis direction, the direction along the Y-axis is set as the Y-axis direction, and the direction along the Z-axis is set as the Z-axis direction, the brush holder comprises: a handle having an axis extending in the X-axis direction; a brush holder supported on one end portion of the handle in the X-axis direction; a brush holder hole provided on an annular outer peripheral surface around the Y-axis in the brush holder; a positioning mechanism for positioning the brush holder at a first rotation angle position around the Y-axis or at a second rotation angle position different from the first rotation angle position; and a fixing mechanism for fixing the positioned brush holder to the handle, wherein when the brush is held in the brush holder hole, the brush protrudes radially outward from the brush holder and extends outward from the handle when viewed from the Y-axis direction. [Effects of the Invention] According to the polishing brush and brush holder of the present invention, the extension direction of the brush can be changed back and forth in multiple directions. Furthermore, according to the polishing brush and brush holder of the present invention, even if the extension direction is changed, the extension direction of the brush can be accurately returned to the extension direction before the change. Hereinafter, an abrasive brush according to an embodiment of the present invention will be described with reference to the drawings. (Abrasive Brush) Figure 1 is a perspective view of an abrasive brush. Figure 2 is an exploded perspective view of the abrasive brush as viewed from the side of the brush holder. Figure 3 is an exploded perspective view of the abrasive brush as viewed from the side of the brush holder. Figure 4 is a top view of the abrasive brush. Figure 5 is a perspective view of the brush. The grinding brush 1 of this embodiment is used for grinding a rotating workpiece. In this embodiment, the grinding brush 1 is connected to the tool holder of a lathe to grind a workpiece that is chucked (chunked) on the main shaft of the lathe and rotated. Here, the grinding brush 1 is also connected to the main shaft of a multi-axis machining center to grind a rotating workpiece. As shown in Figures 1, 2 and 3, the grinding brush 1 includes a brush holder 2 and a brush 3 held by the brush holder 2. The brush holder 2 includes a handle 5 extending in a straight line and a brush holding part 6, which is supported by a support portion 11 provided on the front end portion of the handle 5. As shown in Figure 4, the brush holding component 6 is a regular polygon when viewed from a direction perpendicular to the axis L0 of the handle 5. The brush 3 is detachably held in a brush holding hole 7 formed on the annular outer peripheral surface of the brush holding component 6. The brush 3 protrudes outward from the brush holding component 6 in the radial direction. In addition, the brush 3 extends outward from the handle 5 when viewed from the direction of the central axis L1 of the brush holding component 6 perpendicular to the axis L0 of the handle 5. In addition, the brush holding seat 2 is equipped with a limiting component 8, which is used to limit the expansion of the brush 3 during grinding. The limiting component 8 is installed on the front end portion of the handle 5. In the following description, the three mutually orthogonal axes are set as the X-axis, Y-axis, and Z-axis, the direction along the X-axis is set as the X-axis direction, the direction along the Y-axis is set as the Y-axis direction, and the direction along the Z-axis is set as the Z-axis direction. In addition, the axis L0 of the handle 5 is set as the X-axis. The center axis L1 of the brush holding component 6 is set as the Y-axis. The axis passing through the intersection of the axis L0 of the handle 5 and the center axis L1 of the brush holding component 6 and being orthogonal to the X-axis and the Y-axis is set as the Z-axis. Next, in the X-axis direction, the front end side of the handle 5 is set as the X1 direction, and the base end side is set as the X2 direction. In addition, in the Y-axis direction, the side of the brush holding component 6 relative to the handle 5 is set as the Y1 direction, and the opposite side is set as the Y2 direction. One side of the Z-axis direction is set as the Z1 direction, and the other side is set as the Z2 direction. Here, the Z-axis direction is the direction along the lathe spindle axis L0 when the abrasive brush 1 is connected to the lathe tool holder. In other words, the Z-axis direction is the direction along the central axis of rotation of the workpiece supported by the lathe spindle. Furthermore, in the following description, the radial direction is the direction centered on the Y-axis. (Handle) As shown in Figure 2, the handle 5 is in the shape of a square prism as a whole. The surface of the support portion 11 facing the Y1 direction is perpendicular to the Y axis. The support portion 11 that supports the brush holding component 6 is provided at the end portion (front end portion) of the handle 5 in the X1 direction. The surface of the support portion 11 facing the Y1 direction is a loading surface 12 on which the brush holding component 6 is loaded. In the handle 5, a wall portion 13 is provided at an adjacent position in the X2 direction of the support portion 11. The wall portion 13 rises vertically in the Y-axis direction from the surface of the handle 5 facing the Y1 direction. The wall portion 13 extends in the Z-axis direction and crosses the surface of the handle 5 facing the Y1 direction in the Z-axis direction. The end portion (base end portion) of the handle 5 in the X2 direction is connected to the tool holder of the lathe. Here, in the handle 5, the front end portion that is further in the X1 direction than the wall portion 13 is thinner than the base side portion that is further in the X2 direction than the wall portion 13. That is, the thickness of the support portion 11 in the Y-axis direction is thinner than the thickness of other portions of the handle 5 in the Y-axis direction. As shown in Figures 2 and 3, the support portion 11 has a fixing hole 14 extending through the center thereof in the Y-axis direction. Fixing hole 14 has a large-diameter portion 15 and a small-diameter portion 16 extending from the Y2 direction side toward the Y1 direction, with the inner diameter of the large-diameter portion 15 being smaller than that of the large-diameter portion 15. Therefore, the support portion 11 has an annular end surface 17 extending from the large-diameter portion 15 and the small-diameter portion 16 within the inner circumference of fixing hole 14, extending toward the Y2 direction. A headed fixing screw 18 is inserted into fixing hole 14 from the Y2 direction side to secure the brush retaining member. The wall portion 13 has a shape that is plane-symmetrical with respect to an imaginary plane containing the X-axis and the Y-axis. The surface of the wall portion 13 facing the X1 direction is perpendicular to the mounting surface 12. As shown in Figures 2 and 4, the surface of the wall portion 13 facing the X1 direction has a curved surface 20 that is recessed in the Y2 direction at the center in the Z-axis direction. In addition, the surface of the wall portion 13 facing the X1 direction has a first plane 21 (first positioning surface) and a second plane 22 (second positioning surface) located on both sides of the curved surface 20 in the Z direction. Furthermore, the surface of the wall portion 13 facing the X1 direction has a third plane 23 located on the opposite side of the curved surface 20 of the first plane 21 and a fourth plane 24 located on the opposite side of the curved surface 20 of the second plane 22. The third plane 23 is inclined in the X2 direction from the first plane 21 toward the Z1 direction. The fourth plane 24 is inclined in the X2 direction from the second plane 22 toward the Z2 direction. As shown in FIG2 , a pair of first threaded holes 26a are provided on the front end surface 26 of the support portion 11 (the surface of the shank 5 facing the X1 direction), arranged at predetermined intervals in the Z-axis direction. As shown in FIG3 , a pair of second threaded holes 27a are provided on the side surface 27 of the support portion 11 facing the Z1 direction, arranged at predetermined intervals in the X-axis direction. As shown in FIG2 , a pair of third threaded holes 28a are provided on the side surface 28 of the support portion 11 facing the Z2 direction, arranged at predetermined intervals in the X-axis direction. The first threaded holes 26a, the second threaded holes 27a, and the third threaded holes 28a are provided to secure the limiting member 8 to the shank 5. (Brush holding component) The brush holding component 6 has a fixed thickness in the Y-axis direction. In this embodiment, the outline shape of the brush holding component 6 is a regular octagon. Therefore, as shown in Figures 2 and 3, the brush holding component 6 is provided with: a first end face 31 and a second end face 32 of a regular octagon extending perpendicularly and parallel to the Y-axis, and an annular outer peripheral surface 33 extending in the Y-axis direction and connecting the first end face 31 and the second end face 32. When viewed from the Y-axis direction, the annular outer peripheral surface 33 has eight outer peripheral surface portions 33a and eight ridges 33b. The outer peripheral surface portion 33a extends linearly in the circumferential direction of the Y-axis, and the ridge 33b is located between two adjacent outer peripheral surface portions 33a in the circumferential direction. As shown in Figures 2, 3, and 4, the brush holding component 6 includes a first brush holding hole 7 (1) and a second brush holding hole 7 (2) as the brush holding hole 7. The first brush holding hole 7 (1) is provided on one of the eight outer peripheral surface portions 33a, and the second brush holding hole 7 (2) is provided across one of the eight ridges 33b. The first brush holding hole 7 (1) and the second brush holding hole 7 (2) extend linearly inward in the radial direction, respectively. The first brush holding hole 7 (1) and the second brush holding hole 7 (2) are separated by an angular interval of 157.5° around the Y axis. As shown in Figures 2 and 4, a first through hole 35 is provided on the first end surface 31 of the brush holding component 6 facing the Y1 direction at a position overlapping with the first brush holding hole 7 (1) in the Y-axis direction. Furthermore, a second through hole 36 is provided on the first end surface 31 at a position overlapping with the second brush holding hole 7 (2) in the Y-axis direction. The first through hole 35 is connected to the first brush holding hole 7 (1), and the second through hole 36 is connected to the second brush holding hole 7 (2). The first through hole 35 and the second through hole 36 are separated by an angular interval of 157.5° around the Y-axis. The brush 3 is selectively held in one of the first brush holding hole 7 (1) and the second brush holding hole 7 (2). In addition, the brush 3 is fixed to the brush holding component 6 by a brush fixing screw 38 inserted into the first through hole 35 or the second through hole 36. 3 , the brush holding member 6 includes a screw hole 39 at the center of the second end surface 32 facing the Y2 direction. The screw hole 39 extends from the second end surface 32 to the center of the brush holding member 6 in the Y-axis direction. (Brush) As shown in Figure 5, the brush 3 has an abrasive bundle 41 composed of a plurality of linear abrasives 41a and an abrasive bundle holder 42 that holds one end portion of the abrasive bundle 41. The linear abrasive 41a is a collection of inorganic long fibers impregnated with resin and then solidified. In other words, the linear abrasive 41a is a collection of inorganic long fibers and a resin impregnated with the collection of fibers. As inorganic long fibers, alumina fibers, silicon carbide fibers, boron fibers, or glass fibers can be used. In this embodiment, the inorganic long fibers are alumina fibers. In addition, as the linear abrasive 41a, there are also cases where materials composed of nylon, nylon with added abrasive grains, rubber with added abrasive grains, stainless steel, or brass are used. In this embodiment, the abrasive bundle 41 is such that the end portion on the opposite side of the side where the abrasive bundle holder 42 is held is adjusted to a conical shape. The abrasive bundle holder 42 includes a cylindrical portion 43 that surrounds the end of the abrasive bundle 41 from the outer circumference and a bottom portion 44 that closes an opening of the cylindrical portion 43. The cylindrical portion 43 is cylindrical. The bottom portion 44 is disc-shaped. The inner circumference of the cylindrical portion 43 and the end surface of the cylindrical portion 43 in the bottom portion 44 constitute the abrasive holding hole 40 for holding the abrasive bundle 41. The end of the abrasive bundle 41 inserted into the cylindrical portion 43 abuts against the bottom portion 44. The abrasive bundle 41 is fixed to the abrasive bundle holder 42 by an adhesive injected into the abrasive holding hole 40. The bottom portion 44 is provided with a threaded hole 45 for fixing a brush that passes through the bottom portion 44 in the radial direction. (Restriction Member) As shown in Figures 2 and 3, the restriction member 8 comprises a plate portion 48 and a connecting portion 49. The plate portion 48 is generally rectangular with its long sides extending in the Y-axis direction, while the connecting portion 49 is a rectangular parallelepiped protruding from one side of the plate portion 48 along its long sides. The end surface of the connecting portion 49 opposite the plate portion 48 serves as an abutment surface 49a, which abuts the handle 5 when the restriction member 8 is secured to the handle 5. One side of the plate portion 48 along its long sides, where the connecting portion 49 is connected, comprises an elongated hole 50 extending in the short-side direction of the plate portion 48. As shown in Figure 3, the elongated hole 50 extends through the connecting portion 49 and opens into the abutment surface 49a of the connecting portion 49. As shown in Figure 2, the elongated hole 50 comprises an annular step portion extending from the plate portion 48 toward the abutment surface 49a in the depth direction. The annular step portion comprises an annular end surface 50a facing the plate portion 48. When the limiting member 8 is fixed to the handle 5 , two limiting member fixing screws 51 with heads are inserted into the long holes 50 . A circular opening 52 is provided on the other side of the plate portion 48 in the longitudinal direction, that is, the protruding portion 48a of the plate portion 48 that protrudes from the connecting portion 49. The circular opening 52 is located in the center of the plate portion 48 in the transverse direction. The inner diameter of the circular opening 52 is larger than the outer diameter of the abrasive bundle 41 of the brush 3. Furthermore, a first notch recess 53 is provided on one side of the circular opening 52 in the transverse direction of the plate portion 48 in the protruding portion 48a, extending from one end edge of the plate portion 48 toward the circular opening 52. Furthermore, a second notch recess 54 is provided on the other side of the circular opening 52 in the transverse direction of the plate portion 48 in the protruding portion 48a, extending from the other end edge of the plate portion 48 toward the circular opening 52. The opening edges of the first notch recess 53 and the second notch recess 54 are arc-shaped, having the same curvature as that of the circular opening 52. (Brush mounted on brush holding member) When the brush 3 is held in the brush holding seat 2, the abrasive bundle holding seat 42 of the brush 3 is inserted into the first brush holding hole 7 (1) or the second brush holding hole 7 (2). As shown in FIG1 , when the brush 3 is inserted into the first brush holding hole 7 (1), the brush fixing screw 38 is screwed into the brush fixing threaded hole 45 of the abrasive bundle holding seat 42 inserted into the first brush holding hole 7 (1) through the first through hole 35. Here, when the brush fixing screw 38 is screwed into the brush fixing threaded hole 45, the brush fixing screw 38 passes through the abrasive bundle holding seat 42 in the Y-axis direction, and its front end abuts against the opposite surface portion of the inner peripheral wall surface of the first brush holding hole 7 (1) opposite to the first through hole 35. When the brush fixing screw 38 is further screwed in from this state, the abrasive bundle holding seat 42 is pressed against the peripheral wall portion opposite to the opposite surface (including the peripheral wall portion of the opening edge of the first through hole 35) on the inner peripheral wall surface of the first brush holding hole 7 (1). In this way, the brush 3 is fixed to the brush holding member 6. Moreover, when the brush 3 is inserted into the second brush holding hole 7 (2), the brush fixing screw 38 is screwed into the brush fixing threaded hole 45 of the abrasive bundle holding seat 42 inserted into the second brush holding hole 7 (2) through the second through hole 36. In this way, the brush 3 is held in the second brush holding hole 7 (2). (Brush Holding Component Attached to Handle) As can be seen from Figures 2 and 3, when attaching the brush holding component 6 holding the brush 3 to the handle 5, the fixing screw 18 is inserted from the Y2 direction into the fixing hole 14 provided in the center of the support portion 11 of the handle 5. Furthermore, the brush holding component 6 is placed on the mounting surface 12 of the support portion 11, and the fixing screw 18 is screwed into the threaded hole 39 of the brush holding component 6. The fixing screw 18 is screwed in until its head abuts against the annular end surface 17 of the fixing hole 14. Here, when the brush holding component 6 is placed on the loading surface 12, the brush holding component 6 is rotated around the Y-axis so that the brush 3 is extended in the desired direction around the Y-axis. Then, as shown in Figures 1 and 4, the annular outer peripheral surface 33 of the brush holding component 6 is brought into contact with the first plane 21 and the second plane 22 of the wall portion 13. In this way, the first plane 21 and the second plane 22 are in surface contact with each of the two outer peripheral surface portions 33a from the outside in the radial direction. Therefore, the brush holding component 6 is changed to a state of being positioned at a predetermined rotation angle position around the Y-axis. That is, the first plane 21 and the second plane 22 of the wall portion 13 and the outer peripheral surface portion 33a of the brush holding component 6 are the positioning mechanism 60 for positioning the brush holding component 6 around the Y-axis. After the brush holding member 6 is positioned at the desired rotation angle position around the Y-axis, when the fixing screw 18 is screwed into the screw hole 39, the brush holding member 6 is fixed to the support portion 11 of the handle 5 in the positioned state. Therefore, the fixing screw 18 and the threaded hole 39 of the brush holding member 6 constitute the fixing mechanism 61 that fixes the positioned brush holding member 6 to the aforementioned handle 5. Here, as shown in FIG1 , when the brush 3 is held in the first brush holding hole 7 (1), the brush holding member 6 can be positioned at five rotation angle positions within a range where the brush 3 does not interfere with the wall portion 13. Therefore, when the brush 3 is held in the first brush holding hole 7 (1), the brush 3 can be extended in five different directions. Furthermore, when the brush 3 is held in the second brush holding hole 7 (2), the brush holding member 6 can be positioned at six rotation angle positions within a range where the brush 3 does not interfere with the wall portion 13. Therefore, when the brush 3 is held in the second brush holding hole 7 (2), the brush 3 can be extended in six different directions. Therefore, at the grinding brush 1, by positioning the brush holding member 6 at the first to eleventh rotation angle positions around the Y axis, the brush 3 can be extended in eleven different directions. Figures 6 and 7 are explanatory diagrams of the extension direction of the brush 3. As shown in Figure 6, when the brush 3 protrudes from the X-axis toward the X1 direction (0°) as the first direction A, the extension direction of the brush 3 can be changed to a second direction B inclined 22.5° from the first direction A toward the Z1 direction, a third direction C inclined 45° from the first direction A toward the Z1 direction, a fourth direction D inclined 67.5° from the first direction A toward the Z1 direction, a fifth direction E inclined 90° from the first direction A toward the Z1 direction, and a sixth direction F inclined 112.5° from the first direction A toward the Z1 direction. When the brush 3 is directed toward the fifth direction E, the brush 3 extends in the Z1 direction. When the brush 3 is directed toward the sixth direction F, the brush 3 extends radially outward in the X2 direction. When the brush 3 is extended along the first direction A, the third direction C, and the fifth direction E, the brush 3 is retained in the first brush retaining hole 7 (1). When the brush 3 extends along the second direction B, the fourth direction D, and the sixth direction F, the brush 3 is held in the second brush holding hole 7 ( 2 ). In addition, as shown in Figure 7, the extension direction of the brush 3 can be changed to the seventh direction G inclined 22.5° from the first direction A to the Z2 direction, the eighth direction H inclined 45° from the first direction A to the Z2 direction, the ninth direction I inclined 67.5° from the first direction A to the Z2 direction, the tenth direction J inclined 90° from the first direction A to the Z2 direction, and the eleventh direction K inclined 112.5° from the first direction A to the Z2 direction. When the brush 3 is directed toward the tenth direction J, the brush 3 extends in the Z2 direction. When the brush 3 is directed toward the eleventh direction K, the brush 3 extends radially outward in the X2 direction. When the brush 3 is extended along the eighth direction H and the tenth direction J, the brush 3 is retained in the first brush retaining hole 7 (1). When the brush 3 is extended along the seventh direction G, the ninth direction I, and the eleventh direction K, the brush 3 is retained in the second brush retaining hole 7 (2). (Installation of the limiting component) Figure 8 is an explanatory diagram of an example of fixing the limiting component 8 to the handle 5. The limiting component 8 is fixed to the front end face 26 of the support portion 11, the side face 27 in the Z1 direction, or the side face 28 in the Z2 direction. More specifically, as shown in Figure 8, when the brush 3 is facing any one of the first direction A, the second direction B, and the seventh direction G, the limiting component 8 is fixed to the front end face 26 (the end face in the X1 direction) of the support portion 11. That is, the abutting surface 49a of the connecting portion 49 is brought into contact with the front end face 26 of the support portion 11, and two limiting component fixing screws 51 are inserted into the long hole 50 from the side of the plate portion 48 and screwed into the pair of first threaded holes 26a provided on the front end face 26. The two limiting component fixing screws 51 are screwed in until their heads abut against the annular end face 50a of the long hole 50. Here, when the brush 3 is oriented in the first direction A, the abrasive bundle 41 of the brush 3 is passed through the circular opening 52. With the abrasive bundle 41 of the brush 3 passing through the circular opening 52, the opening edge (opposing portion) of the circular opening 52 in the limiting member 8 faces the portion between the front end of the abrasive bundle 41 and the brush holding member 6 from both sides in the circumferential direction around the Y axis (both sides in the Z axis direction), separated by a predetermined gap. When the brush 3 is oriented in the second direction B, the opening edge (opposing portion) of the first notch recess 53 in the limiting member 8 faces the portion between the front end of the abrasive bundle 41 and the brush holding member 6 from the other side in the circumferential direction around the Y axis (the side in the Z2 direction), separated by a predetermined gap. When the brush 3 is facing the seventh direction G, the opening edge (opposite portion) of the second cutout recess 54 in the limiting component 8 corresponds to the portion between the front end of the abrasive bundle 41 and the brush holding component 6 from one side in the circumferential direction around the Y axis (the side in the Z1 direction), separated by a predetermined gap. Furthermore, when the brush 3 is oriented in any of the fourth, fifth, and sixth directions (F), the limiting member 8 is fixed to the Z1-direction side surface 27 of the support portion 11. Specifically, the abutting surface 49a of the connecting portion 49 is brought into contact with the Z1-direction side surface 27 of the support portion 11, and two limiting member fixing screws 51 are threaded through the elongated hole 50 from the side of the plate portion 48 and into a pair of second threaded holes 27a provided on the Z1-direction side surface 27 of the support portion 11. Here, when the brush 3 is oriented in the fifth direction (E), the abrasive bundle 41 of the brush 3 is passed through the circular opening 52. With the abrasive bundle 41 of the brush 3 passed through the circular opening 52, the opening edge of the circular opening 52 in the limiting member 8 faces the portion between the tip of the abrasive bundle 41 and the brush holding member 6 from both sides in the circumferential direction around the Y axis (both sides in the X axis), separated by a predetermined gap. When the brush 3 is oriented in the sixth direction F, the opening edge of the first notch recess 53 in the limiting member 8 corresponds to the portion between the front end of the abrasive bundle 41 and the brush holding member 6 from the other side in the circumferential direction around the Y axis (the side in the X1 direction), separated by a predetermined gap. When the brush 3 is oriented in the fourth direction D, the opening edge of the second notch recess 54 in the limiting member 8 corresponds to the portion between the front end of the abrasive bundle 41 and the brush holding member 6 from the one side in the circumferential direction around the Y axis (the side in the X2 direction), separated by a predetermined gap. Furthermore, when the brush 3 is oriented in any of the ninth, tenth, and eleventh directions (I, J, and K), the limiting member 8 is fixed to the Z2-direction side surface 28 of the support portion 11. Specifically, the abutting surface 49a of the connecting portion 49 is brought into contact with the Z2-direction side surface 28 of the support portion 11, and two limiting member fixing screws 51 are threaded through the elongated hole 50 from the side of the plate portion 48 and into a pair of third threaded holes 28a provided on the Z2-direction side surface 28 of the support portion 11. Here, when the brush 3 is oriented in the tenth direction (J), the abrasive bundle 41 of the brush 3 is passed through the circular opening 52. With the abrasive bundle 41 of the brush 3 passed through the circular opening 52, the opening edge of the circular opening 52 in the limiting member 8 faces the portion between the tip of the abrasive bundle 41 and the brush holding member 6 from both sides in the circumferential direction around the Y axis (both sides in the X axis), separated by a predetermined gap. When the brush 3 is oriented in the ninth direction I, the opening edge of the first notch recess 53 in the limiting member 8 corresponds to the portion between the front end of the abrasive bundle 41 and the brush holding member 6 from the other side in the circumferential direction around the Y axis (the side in the X2 direction), separated by a predetermined gap. When the brush 3 is oriented in the eleventh direction K, the opening edge of the second notch recess 54 in the limiting member 8 corresponds to the portion between the front end of the abrasive bundle 41 and the brush holding member 6 from the one side in the circumferential direction around the Y axis (the side in the X1 direction), separated by a predetermined gap. Here, when the limiting member 8 is attached to the handle 5, any one of the opening edge of the circular opening 52, the opening edge of the first notch recess 53, and the opening edge of the second notch recess 54 in the limiting member 8 becomes an opposing portion that is spaced apart from the abrasive bundle 41 by a predetermined distance around the Y-axis. Therefore, during grinding, if the brush 3 expands due to a load applied to the brush 3 from the workpiece side, the expanded abrasive bundle 41 contacts the opposing portion of the limiting member 8 (the opening edge of the circular opening 52, the opening edge of the first notch recess 53, or the opening edge of the second notch recess 54), thereby limiting further expansion of the brush 3. Furthermore, when the brush 3 is oriented in the third direction C or the eighth direction H, the limiting member 8 is not required on the handle 5. In other words, when the brush 3 is oriented in the third direction C or the eighth direction H, the brush 3 is tilted 45° relative to the lathe spindle during grinding. In this case, the rigidity of the abrasive bundle 41 during contact with the workpiece is more easily maintained than when the brush 3 is oriented in other directions. Therefore, even without the limiting member 8, the expansion of the brush 3 can be suppressed. (Grinding method) Next, examples of grinding processes of various types of parts (workpieces) performed by the grinding brush 1 of this embodiment are described. FIG9 is a first example of a method for grinding a workpiece using the grinding brush 1. FIG10 is a second example of a method for grinding a workpiece using the grinding brush 1. FIG11 is a third example of a method for grinding a workpiece using the grinding brush 1. FIG12 is a fourth example of a method for grinding a workpiece using the grinding brush 1. As shown in FIG9 to FIG12, during grinding, the part is supported on the spindle 101 of the lathe 100 and rotates around the rotation center axis L of the spindle 101. Here, the direction along the rotation center axis L of the spindle 101 is the Z-axis direction in the grinding brush 1. Figure 9 shows an example of grinding of the first threaded member 65. The first threaded member 65 comprises a disc-shaped head 66 and a shaft 67 protruding from the head 66. The shaft 67 comprises a threaded portion 68 with external threads extending from the distal end toward the head 66, and an annular groove 69. The threaded portion 68 is formed by tapping. In such a first threaded member 65, burrs may form at the cutting end 68a of the threaded portion 68 (the boundary between the threaded portion 68 and the annular groove 69). When removing the burrs from the cutting end portion 68a of the threaded portion 68, the brush 3 is held in the second brush holding hole 7(2) of the brush holding member 6. Furthermore, the brush holding member 6 is positioned at a predetermined rotation angle about the Y axis relative to the handle 5, so that the brush 3 extends in the second direction B. Then, the grinding brush 1 with the brush 3 directed in the second direction B is connected to the tool holder 102 in a posture in which the handle 5 extends in the X-axis direction. Then, while the first threaded member 65 is rotated about the rotation center axis L of the spindle 101, the tip of the brush 3 is brought into contact with the cutting end portion 68a of the threaded portion 68. In this embodiment, the brush 3 contacts the cut end portion 68a of the first screw member 65 at an angle of 67.5 degrees. In this embodiment, since the brush 3 can contact the outer peripheral surface of the first screw member 65 at a larger angle, burrs generated on the cut end portion 68a can be removed. Figure 10 shows an example of grinding the second threaded member 71. The second threaded member 71 is rod-shaped and relatively long in the direction of the axis L0. The second threaded member 71 comprises a threaded portion 72 with external threads formed from the distal end to the proximal end, and a cylindrical portion 73 without external threads. The threaded portion 72 is formed by tapping. In such a second threaded member 71, burrs may form on the outer circumference of the second threaded member 71, such as at the top of the external threads or at the boundary between the threaded portion 72 and the cylindrical portion 73. Here, when removing burrs from the outer peripheral surface of a long component such as the second threaded part 71, as shown in FIG10, the second threaded part 71 is supported on the spindle 101 of the lathe 100, and the front end of the second threaded part 71 is supported by the tailstock 103 of the lathe 100. Furthermore, the brush 3 is held in the second brush holding hole 7 (2) of the brush holding part 6. Next, the brush holding part 6 is positioned at a predetermined rotation angle position around the Y axis relative to the handle 5 so that the brush 3 is extended in the fourth direction D. Then, the grinding brush 1 with the brush 3 facing the fourth direction D is connected to the tool holder 102 in a posture in which the handle 5 extends in the X-axis direction. Then, the first threaded part 65 is rotated around the rotation center axis L of the spindle 101 while being brought into contact with the outer peripheral surface of the second threaded part 71. In this embodiment, the brush 3 contacts the outer circumference of the second threaded member 71 at an angle of 22.5°. Furthermore, in this embodiment, the handle 5 is positioned in the X2 direction relative to the second threaded member 71, and the brush 3 extends from the handle 5 in the X1 direction. Therefore, during the grinding process, the grinding brush 1 does not interfere with the tailstock 103, and burrs on the outer circumference of the second threaded member 71 can be removed. Figure 11 shows an example of grinding of the third threaded component 75. The third threaded component 75 comprises a disc-shaped head 76 and a shaft 77 protruding from the head 76. The shaft 77 comprises a threaded portion 78 with external threads extending from the distal end toward the head 76, and an annular groove 79. The threaded portion 78 is formed by tapping. Furthermore, the threaded portion 78 is provided with a radially recessed hole 80. In such a third threaded component 75, burrs may form at the opening edge of the hole 80 in the valley 78a of the external threads. When removing the burrs from the valley bottom 78a of the external thread, as shown in FIG11 , the brush 3 is held in the first brush holding hole 7 (1) of the brush holding member 6. Furthermore, the brush holding member 6 is positioned at a predetermined rotation angle about the Y axis relative to the handle 5 so that the brush 3 extends in the first direction A. The grinding brush 1 with the brush 3 directed in the first direction A is then connected to the tool holder 102 in a posture in which the handle 5 extends in the X-axis direction. Then, while the third threaded member 75 is rotated about the rotation center axis L of the spindle 101, the front end of the brush 3 is brought into contact with the valley bottom 78a of the external thread. In this embodiment, the brush 3 contacts the threaded portion 78 of the third threaded member 75 from a vertical direction. In this embodiment, since the brush 3 can contact the threaded portion 78 of the third threaded member 75 from a vertical direction, burrs generated on the valley bottoms 78a of the external threads in the threaded portion 78 can be removed. FIG12 shows an example of grinding of a disk member 81. The disk member 81 has a circular recess 82 at the center of one end surface. The circular recess 82 is formed by cutting. In such a disk member 81, burrs may be generated on the annular inner circumference of the circular recess 82. When removing the burrs generated on the annular inner circumference of the circular recess 82, as shown in FIG12 , the brush 3 is held in the second brush holding hole 7 (2) of the brush holding member 6. Furthermore, the brush holding member 6 is positioned at a predetermined rotation angle position around the Y axis relative to the handle 5 so that the brush 3 is extended in the sixth direction F. Then, the grinding brush 1 with the brush 3 facing the sixth direction F is connected to the tool holder 102 in a posture in which the handle 5 extends in the X-axis direction. Then, while the disc member 81 is rotated around the rotation center axis L of the main shaft 101, the front end of the brush 3 is brought into contact with the annular inner circumference of the circular recess 82. In this embodiment, the polishing brush 1 can orient the brush 3 in the sixth direction F, facing the base end side (X2 direction) of the handle 5 , so as to polish the inner circumference of the circular recess 82 provided on the end surface of the disk member 81 . (Function and Effect) According to the abrasive brush 1 of this embodiment, the brush 3 extends radially outward from the brush holder 6, centered on the Y-axis. The brush holder 6 is supported by the distal end of the handle 5, which extends in the X-axis direction, and is secured to the handle 5 while being positioned at a plurality of rotational angles about the Y-axis. Therefore, by securing the brush holder 6 to the handle 5 at various rotational angles about the Y-axis, the direction in which the brush 3 is extended can be changed. Therefore, even when the handle 5 is connected to the tool holder 102 of the lathe 100 without using an angle adjustment fixture or the like, the direction in which the brush 3 is extended can be changed. Furthermore, the brush holding member 6 is positioned at a plurality of rotational angles. Therefore, even if the extension direction of the brush 3 is changed, the extension direction of the brush 3 can be accurately returned to the extension direction before the change. In other words, the polishing brush 1 of this embodiment can accurately reproduce the extension direction of the brush 3 before the change. In this embodiment, the brush holder 6 has a regular polygonal outline when viewed from the Y-axis. Furthermore, the handle 5 includes a first flat surface 21 and a second flat surface 22, serving as a positioning mechanism 60. These flat surfaces 21 and 22 are configured to contact, radially outward, two linearly extending circumferential outer surface portions 33a of the annular outer circumferential surface 33 of the brush holder 6. Therefore, after the brush holder 6 is positioned by the positioning mechanism 60, circumferential movement of the brush holder 6 can be prevented or suppressed. In this embodiment, the brush holding hole 7 provided on the annular outer peripheral surface 33 of the brush holding member 6 is recessed radially inward. Furthermore, the brush holding member 6 includes a first brush holding hole 7 (1) and a second brush holding hole 7 (2) as the brush holding holes 7. The first brush holding hole is provided on the outer peripheral surface portion 33a extending linearly in the circumferential direction on the annular outer peripheral surface 33, while the second brush holding hole is provided across the ridge line 33b between the two outer peripheral surface portions 33a extending linearly in the circumferential direction on the annular outer peripheral surface 33. In addition, the brush 3 is selectively held in the first brush holding hole 7 (1) or the second brush holding hole 7 (2). Therefore, the extending direction of the brush 3 can be changed between the case where the brush 3 is held in the first brush holding hole 7 (1) and the case where the brush 3 is held in the second brush holding hole 7 (2). Therefore, the brush holding member 6 has a structure with two brush holding holes 7 and a structure that positions and fixes the brush holding member 6 at multiple rotation angle positions around the Y axis. The combination of the two can improve the resolution of the direction in which the brush 3 is extended. Furthermore, in this embodiment, as shown in the second illustration from the right in FIG. 6 , when the brush holder 6 is positioned at a predetermined rotational angle position (first rotational angle position) and secured to the handle 5, the brush 3 extends radially outward from the brush holder 6 in a second direction B that is further in the X1 direction than the Z axis. From this state, as shown in the leftmost illustration in FIG. 6 , when the brush holder 6 is positioned at a different rotational angle position (second rotational angle position) and secured to the handle 5, the brush 3 extends radially outward from the brush holder 6 in a sixth direction F that is further in the X2 direction than the Z axis. Therefore, the abrasive brush 1 of this embodiment can perform the abrasive processes shown in FIG. 9 to FIG. 11 and the two abrasive processes shown in FIG. 12 . Furthermore, in this embodiment, when the brush holder 6 is positioned at a predetermined rotational angle position (first rotational angle position) and secured to the handle 5, as shown in the third illustration from the right in FIG6 , the brush 3 extends radially outward of the brush holder 6 and in a third direction C, which is further in the Z1 direction than the X-axis. From this state, as shown in the second illustration from the left in FIG7 , when the brush holder 6 is positioned at a different rotational angle position (second rotational angle position) and secured to the handle 5, the brush 3 extends radially outward of the brush holder 6 and in an eighth direction H, which is further in the Z2 direction than the X-axis. Therefore, the abrasive brush 1 according to this embodiment can perform abrasive processing whether the workpiece is positioned in the Z1 direction relative to the abrasive brush 1 or the Z2 direction relative to the abrasive brush 1. Furthermore, the brush holder 2 of this embodiment comprises: a handle 5 having an axis L0 extending in the X-axis direction; a brush holder 6 supported by one end portion of the handle 5 in the X-axis direction; a brush holding hole 7 provided on the annular outer peripheral surface 33 of the brush holder 6 about the Y-axis; a positioning mechanism 60 for positioning the brush holder 6 at a plurality of rotational angles about the Y-axis; and a fixing mechanism 61 for fixing the positioned brush holder 6 to the handle 5. Furthermore, when the brush 3 is retained in the brush holding hole 7 of the brush holder 2, the brush 3 protrudes radially outward from the brush holder 6 and extends outward from the handle 5 when viewed in the Y-axis direction. Therefore, after the brush 3 is retained in the brush holder 6, the brush holder 6 can be rotated about the Y-axis to position and fix it, thereby changing the direction in which the brush 3 extends. (Variation Example) In the above example, the brush holding member 6 is positioned by having the first flat surface 21 and the second flat surface 22 of the wall portion 13 abut against the two outer peripheral surface portions 33a of the brush holding member 6 from the radial outside. However, the brush holding member 6 may be positioned by having a single positioning surface provided on the wall portion 13 abut against one outer peripheral surface portion 33a of the brush holding member 6 from the radial outside. Furthermore, the brush holding member 6 may be positioned by having three positioning surfaces provided on the wall portion 13 abut against the three outer peripheral surface portions 33a of the brush holding member 6 from the radial outside, respectively. Figure 13 is an explanatory diagram of an example in which the positioning mechanism 60 has three positioning surfaces (planes). In this case, the wall portion 13 has a shape that is plane-symmetrical with respect to an imaginary plane containing the X-axis and the Y-axis. The surface of the wall portion 13 facing the X1 direction is perpendicular to the mounting surface 12. The surface of the wall portion 13 facing the X1 direction is a plane 25 (third positioning surface) extending in the Z-axis direction at the center of the Z-axis direction. Furthermore, the wall portion 13 has a first plane 21 (first positioning surface) and a second plane 22 (second positioning surface) on both sides of the plane 25 in the Z direction, which are adjacent to each other via a recessed portion that is recessed in the X2 direction. In addition, the wall portion 13 has a third plane 23 located on the opposite side of the curved surface 20 of the first plane 21 and a fourth plane 24 located on the opposite side of the curved surface 20 of the second plane 22. The third plane 23 is inclined in the X2 direction from the first plane 21 toward the Z1 direction. The fourth plane 24 is inclined in the X2 direction from the second plane 22 toward the Z2 direction. The brush holding member 6 is positioned about the Y axis by the first flat surface 21 , the second flat surface 22 , and the flat surface 25 provided on the wall portion 13 respectively contacting the three outer peripheral surface portions 33 a of the annular outer peripheral surface 33 from the radially outer side. Furthermore, in the above example, the outline shape of the brush holding member 6 when viewed from the Y-axis direction is a regular octagon, but the outline shape of the brush holding member 6 when viewed from the Y-axis direction may be an equilateral triangle, a square, or a regular polygon of a higher shape. In such a case, the brush holding member 6 may also include a first brush holding hole 7 (1) and a second brush holding hole 7 (2), the first brush holding hole being provided in an outer peripheral surface portion 33a extending linearly in the circumferential direction on the annular outer peripheral surface 33, and the second brush holding hole being provided across the ridge line 33b between the two outer peripheral surface portions 33a extending linearly. Here, Figure 14 is an explanatory diagram of another example of the positioning mechanism. Figure 14(a) is a top view of the support portion 11 of the handle 5 as viewed from the Y-axis direction. Figure 14(b) is a top view of the brush holding component 6 positioned on the handle 5 as viewed from the Y-axis direction. The positioning mechanism 60A of another example shown in Figure 14 comprises: a positioning threaded hole 85 formed at a predetermined angular position around the Y-axis on the mounting surface 12, a positioning threaded insertion hole 86 located on the outer peripheral side of the threaded hole 39 of the brush holding component 6, and a positioning screw 87 screwed into the positioning threaded hole 85 via the positioning threaded insertion hole 86. More specifically, as shown in FIG14(a), the positioning mechanism 60A includes two positioning threaded holes 85 spaced 90° apart around the Y-axis on the mounting surface 12. Furthermore, as shown in FIG14(b), the brush holding member 6 is provided with four positioning threaded insertion holes 86. In this embodiment, the brush holding member 6 includes two positioning threaded insertion holes 86 spaced 180° apart around the Y-axis, and two positioning threaded insertion holes 86 are further provided at two locations spaced 45° apart in the same rotational direction from the two positioning threaded insertion holes 86. To position the brush holder 6 about the Y-axis, as shown in Figure 14(b), a positioning screw 87 is inserted into one of the four positioning threaded insertion holes 86, and the positioning screw 87 is then screwed into one of the two positioning threaded holes 85 formed on the mounting surface 12. This allows the brush holder 6 to be positioned at eleven rotational angles on the handle 5. Thus, the extension direction of the brush 3 can be changed in eleven directions, similar to the abrasive brush 1 described above. Furthermore, the limiting component 8 can also be fixed to the brush holding component 6. Figure 15 is an explanatory diagram of the limiting component fixed to the brush holding component 6. In this case, the limiting component 8A is a cylindrical body, as shown in Figure 15, comprising a cylindrical portion 91 of the abrasive bundle holding seat 42 surrounding the brush 3 from the outer peripheral side and an extended portion 92 extending from the cylindrical portion 91 on the side of the abrasive bundle 41. The cylindrical portion 91 is provided with two through holes 93 at positions 180° apart. The two through holes 93 are connected to the brush fixing threaded hole 45 of the abrasive bundle holding seat 42 by rotating the limiting component 8A surrounding the abrasive bundle holding seat 42 along the outer peripheral surface of the abrasive bundle holding seat 42. The extended portion 92 is cut along an imaginary plane obliquely intersecting the axis L0 of the cylindrical body, and its cross section has an elliptical shape. The extended portion 92 is located on the outer peripheral side of the abrasive bundle 41 held by the brush holding component 6. A predetermined gap is formed between the extended portion 92 and the abrasive bundle 41 . On the other hand, the brush holding hole 7 of the brush holding member 6 has an inner diameter dimension capable of inserting the abrasive bundle holding seat 42 and the cylindrical portion 91 of the cylindrical body surrounding the abrasive bundle holding seat 42 from the outer circumference. When securing the limiting member 8A to the brush holding member 6, the brush 3 is positioned on the inner circumference of the limiting member 8A. By rotating the limiting member 8A on the outer circumference of the abrasive bundle holding seat 42, the brush securing threaded hole 45 of the abrasive bundle holding seat 42 is brought into communication with the two through-holes 93. Next, the cylindrical portion 91 of the limiting member 8A, along with the abrasive bundle holding seat 42, is inserted into the brush holding hole 7, and the brush securing threaded hole 45 is screwed into the brush securing threaded hole 45 of the abrasive bundle holding seat 42. In this manner, the brush 3 and the limiting member 8A are secured to the brush holding member 6. Here, when the two through holes 93 of the limiting member 8A are connected to the brush fixing threaded holes 45 of the abrasive bundle holding seat 42, the portion of the extended portion 92 of the limiting member 8A that extends longer to the front end side of the abrasive bundle 41 can be selectively arranged on one side or the other side of the abrasive bundle 41. Whether the portion of the extended portion 92 of the limiting member 8A that extends longer to the front end side of the abrasive bundle 41 is arranged on one side or the other side of the abrasive bundle 41 is selected based on the extension direction of the brush 3 extending from the handle 5. 1: Abrasive Brush 2: Brush Holder 3: Brush 5: Handle 6: Brush Holder 7: Brush Holder Hole 8: Limiting Component 11: Support 12: Mounting Surface 13: Wall 14: Fixing Hole 15: Large Diameter Portion 16: Small Diameter Portion 17: Annular End Surface 18: Fixing Screw 20: Curved Surface 21: First Plane (First Positioning Surface) 22: Second Plane (Second Positioning Surface) 23: Third Plane 24: Fourth Plane 25: Plane (Third Positioning Surface) 26: Front end face 27: Side face 28: Side face 31: First end face 32: Second end face 33: Annular outer peripheral face 35: First through hole 36: Second through hole 38: Brush fixing screw 39: Threaded hole 40: Abrasive material holding hole 41: Abrasive material bundle 42: Abrasive material bundle holding seat 43: Cylinder 44: Bottom 45: Brush fixing threaded hole 48: Plate portion 49: Connecting portion 50: Long hole 51: Limiting component fixing screw 52: Circular opening 53: First cutout recess 54: Second cutout recess 60: Positioning mechanism 61: Fixing mechanism 65: First threaded component 66: Head 67: Shaft 68: Threaded portion 69: Annular groove 71: Second threaded component 72: Threaded portion 73: Cylindrical portion 75: Third threaded component 76: Head 77: Shaft 78: Threaded portion 79: Annular groove 80: Hole 81: Disc component 82: Circular recess 85: Positioning threaded hole 86: Positioning threaded insertion hole 87 : Positioning screw 91: Cylindrical portion 92: Extended portion 93: Through hole 100: Lathe 101: Spindle 102: Tool holder 103: Tail stock 26a: First threaded hole 27a: Second threaded hole 28a: Third threaded hole 33a: Peripheral surface portion 33b: Ridge line 41a: Linear abrasive material 48a: Protruding portion 49a: Abutment surface 50a: Annular end surface 68a: Cutting end portion 7 (1): First brush holding hole 7 (2): Second brush holding hole 78a: Bottom of external thread 8A: Limiting component A: First direction B: Second direction C: Third direction D: Fourth direction E: Fifth direction F: Sixth direction G: Seventh direction H: Eighth direction I: Ninth direction J: Tenth direction K: Eleventh direction L: Rotation center axis L0: Axis L1: Center axis X: Direction X1: Direction X2: Direction Y: Direction Y1: Direction Y2: Direction Z: Direction Z1: Direction Z2: Direction [Figure 1] is a perspective view of a grinding brush. [Figure 2] is an exploded perspective view of the grinding brush as viewed from the side of the brush holder. [Figure 3] is an exploded perspective view of the grinding brush as viewed from the side of the brush holder. [Figure 4] is a top view of the grinding brush. [Figure 5] is a perspective view of the brush. [Figure 6] is an illustration of the extension direction of the brush. [Figure 7] is an illustration of the extension direction of the brush. [Figure 8] is an illustration of an example of fixing a limiting member to a handle. [Figure 9] is a first example of a method for grinding a workpiece. [Figure 10] is a second example of a method for grinding a workpiece. [Figure 11] is a third example of a method for grinding a workpiece. [Figure 12] is a fourth example of a method for grinding a workpiece. [Figure 13] is an example of a positioning mechanism having three positioning surfaces. [Figure 14] is an illustration of another example of a positioning mechanism. [Figure 15] is an illustration of another example of a limiting member. 1: Abrasive brush 2: Brush holder 3: Brush 5: handle 6: Brush holding component 7(1): First brush holding hole 8: Restricted components 11: Supporting part 13: Wall 26: Front end 26a: First threaded hole 35: First through hole 36: Second through hole 38: Brush fixing screw 48: Board 49:Connection 50: Long hole 52: Circular opening 53: First incision recess 54: Second incision recess 60: Positioning mechanism L0: axis L1: Center axis X: direction X1: Direction X2: Direction Y: direction Y1: Direction Y2: Direction Z: direction Z1: Direction Z2: Direction

Claims

1. An abrasive brush, wherein the three mutually orthogonal axes are designated as X-axis, Y-axis and Z-axis, and the direction along the X-axis is designated as the X-axis direction, the direction along the Y-axis is designated as the Y-axis direction and the direction along the Z-axis is designated as the Z-axis direction, the abrasive brush comprising: a brush holder having a handle having an axis aligned with the X-axis; a brush holding member supported on a front end portion of the handle; a brush holding hole provided in the brush holding member on an annular outer peripheral surface about a Y-axis orthogonal to the X-axis; a positioning mechanism for positioning the brush holding member at a first rotation angle position about the Y-axis or a second rotation angle position different from the first rotation angle position; and a fixing mechanism for fixing the positioned brush holding member to the handle; and a brush detachably held in the brush holding hole, protruding radially outward from the brush holding member and extending outward from the handle when viewed from the Y-axis direction.

2. The abrasive brush as described in claim 1, wherein, The aforementioned brush holding member has a regular polygonal outline when viewed from the aforementioned Y-axis direction; the aforementioned handle has a positioning surface as the aforementioned positioning mechanism, which can make contact with the outer peripheral surface portion extending linearly in the circumferential direction from the radial direction outward on the annular outer peripheral surface of the aforementioned brush holding member.

3. The abrasive brush as described in claim 1, wherein, The aforementioned brush holding member has a regular polygonal outline when viewed from the aforementioned Y-axis direction; the aforementioned handle has a first positioning surface and a second positioning surface as the aforementioned positioning mechanism, which can make surface contact with the two outer peripheral surface portions that extend linearly in the circumferential direction from the radial direction outward on the annular outer peripheral surface of the aforementioned brush holding member.

4. The abrasive brush as described in claim 1, wherein, The aforementioned brush holding member has a regular polygonal outline shape when viewed from the aforementioned Y-axis direction; the aforementioned brush holding hole is recessed inward in the aforementioned radial direction; it has a first brush holding hole and a second brush holding hole as the aforementioned brush holding hole, the aforementioned first brush holding hole is provided on the outer peripheral surface portion of the aforementioned annular outer peripheral surface that extends linearly in the circumferential direction, and the aforementioned second brush holding hole is provided to cross the ridge line located between two adjacent outer peripheral surface portions of the aforementioned annular outer peripheral surface in the circumferential direction; the aforementioned brush is selectively held by the aforementioned first brush holding hole or the aforementioned second brush holding hole.

5. The abrasive brush as described in claim 1, wherein, The aforementioned Z-axis passes through the intersection of the aforementioned X-axis and the aforementioned Y-axis. When the aforementioned brush holding member is positioned at the aforementioned first rotation angle position and fixed to the aforementioned handle, the aforementioned brush extends outward in the aforementioned radial direction in a direction that is closer to the aforementioned X-axis than the aforementioned Z-axis. When the aforementioned brush holding member is positioned at the aforementioned second rotation angle position and fixed to the aforementioned handle, the aforementioned brush extends outward in the aforementioned radial direction in another direction that is closer to the aforementioned X-axis than the aforementioned Z-axis.

6. The abrasive brush as described in claim 1, wherein, The aforementioned Z-axis is the intersection of the aforementioned X-axis and the aforementioned Y-axis; when the aforementioned brush holding member is positioned at the aforementioned first rotation angle position and fixed to the aforementioned handle, the aforementioned brush extends outward in the aforementioned radial direction toward a side closer to the aforementioned Z-axis than the aforementioned X-axis; when the aforementioned brush holding member is positioned at the aforementioned second rotation angle position and fixed to the aforementioned handle, the aforementioned brush extends outward in the aforementioned radial direction toward another side closer to the aforementioned Z-axis than the aforementioned X-axis.

7. The abrasive brush as described in claim 1, wherein, The aforementioned brush has an abrasive bundle consisting of a plurality of linear abrasive materials and an abrasive bundle holder that holds one end portion of the aforementioned abrasive bundle; the aforementioned abrasive bundle holder is inserted into the aforementioned brush holding hole.

8. The abrasive brush as described in claim 1, wherein, The brush has a limiting member fixed to the aforementioned handle to restrict the expansion of the aforementioned brush; the aforementioned brush has an abrasive bundle composed of a plurality of linear abrasive materials and an abrasive bundle holder that holds one end portion of the aforementioned abrasive bundle; the aforementioned abrasive bundle holder is inserted into the aforementioned brush holding hole; the aforementioned limiting member has an opposing portion located between the other end portion of the aforementioned abrasive bundle and the aforementioned brush holding member, and is opposed to the brush by a gap in the circumferential direction surrounding the aforementioned Y-axis.

9. The abrasive brush as described in claim 1, wherein, The brush has a limiting member fixed to the aforementioned brush holding member to restrict the expansion of the aforementioned brush; the aforementioned brush has an abrasive bundle composed of a plurality of linear abrasive materials and an abrasive bundle holding seat that holds one end portion of the aforementioned abrasive bundle; the aforementioned abrasive bundle holding seat is inserted into the aforementioned brush holding hole; the aforementioned limiting member has an extension portion located between the other end portion of the aforementioned abrasive bundle and the aforementioned brush holding member, and is positioned opposite to it from a gap in the circumferential direction surrounding the aforementioned Y-axis.

10. A brush holder for holding a brush, wherein the three mutually orthogonal axes are defined as X-axis, Y-axis and Z-axis, and the direction along the X-axis is defined as the X-axis direction, the direction along the Y-axis is defined as the Y-axis direction and the direction along the Z-axis is defined as the Z-axis direction, the brush holder having: a handle having an axis extending in the X-axis direction; a brush holding member supported at one end portion of the handle in the X-axis direction; a brush holding hole provided in the brush holding member on an annular outer peripheral surface around the Y-axis; a positioning mechanism for positioning the brush holding member at a first rotation angle position around the Y-axis or a second rotation angle position different from the first rotation angle position; and a fixing mechanism for fixing the positioned brush holding member to the handle, wherein when the brush is held in the brush holding hole, the brush protrudes outward from the brush holding member in the radial direction and extends outward from the handle when viewed from the Y-axis direction.

Images