How to cut magnetic material

Abstract

To provide a cutting method for a magnet material, the method enabling magnet material having an arcuate cross-section to be efficiently cut.SOLUTION: In a cutting method for a magnet material S having an arcuate cross-section and extending in a direction orthogonal to the cross-section, a plurality of magnet materials S are fixed in a circumferential direction of a columnar portion 12 by using a magnet-material fixing tool 10 having a columnar portion 12 as a material holding portion for holding the magnet materials in a fixed state in such a manner that recessed curved surfaces 2 of the magnet materials S are made to follow a projecting outer peripheral surface 13 of the columnar portion 12. While the magnet-material fixing tool 10 and a disk-like cutting blade 26 are rotated together, a cutting blade 26 is moved relatively in a direction of each magnet material S and the magnet material S fixed to the magnet-material fixing tool 10 is cut.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for cutting a magnetic material, and more particularly to a method for efficiently cutting a magnetic material having an arc shape. [Background technology]

[0002] When manufacturing metal magnets, such as rare earth magnets, the metal magnet is formed into a desired shape by hot processing such as hot extrusion molding. However, when manufacturing magnets of relatively small sizes, the magnetic material is formed to a size larger than the product, and then this magnetic material is cut to cut out multiple magnetic products from one magnetic material.

[0003] Examples of cutting processes in such cases include a method of cutting the magnetic material by moving a rotating, disk-shaped cutting blade relative to the magnetic material fixed on a table (see Patent Document 1 below), and a method of cutting magnetic products from a block-shaped ingot using wire processing (see Patent Document 2 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-150344 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-050329 Summary of the Invention [Problem to be solved by the invention]

[0005] When manufacturing magnetic products of predetermined dimensions through a cutting process, it is extremely important to perform the cutting process efficiently. In order to perform the cutting process efficiently, it is possible to stack multiple magnetic materials in the thickness direction and cut the multiple materials simultaneously in a single cutting operation. Here, let us consider a case where a magnetic material S having a circular arc cross section as shown in Fig. 14(A) is cut using a disk-shaped cutting blade 26. Assume that six magnetic materials S are cut at a time. When the magnetic material S is stacked vertically as shown in Figure 14(B), the movement distance of the cutting blade 26 from the start of cutting (the position of the cutting blade shown by the solid line) to the end of cutting (the position of the cutting blade shown by the two-dot chain line) (hereinafter referred to as the cutting distance) is K1, and when the magnetic material S is stacked horizontally as shown in Figure 14(C), the cutting distance is K2, but it is difficult to say that the cutting distance is sufficiently short, and it has been desired to shorten this cutting distance in order to perform cutting processing efficiently.

[0006] Furthermore, when an arc-shaped magnetic material is placed on a flat table surface and cut, a gap is likely to occur between the table surface and the magnetic material, which may cause cracks or other problems.

[0007] The present invention has been made in light of the above circumstances and aims to provide a method for cutting a magnetic material that can efficiently perform cutting processing on a magnetic material having an arc-shaped cross section. [Means for solving the problem]

[0008] The method for cutting a magnetic material of the present invention comprises the steps of: A method for cutting a magnetic blank having a cross-sectional shape of an arc and extending in a direction perpendicular to the cross-section, comprising: a magnetic material fixture having a cylindrical portion as a material holding portion that holds the magnetic material in a fixed state; a plurality of magnetic materials are fixed in a circumferential direction of the cylindrical portion in such a manner that the concave curved surface of the magnetic material is aligned with the convex outer peripheral surface of the cylindrical portion; The magnetic material fixing device for a magnetic material, to which the magnetic material is fixed, and a disk-shaped cutting blade are both rotated, and the cutting blade is moved relatively toward the magnetic material to cut the magnetic material fixed to the magnetic material fixing device.

[0009] According to the method for cutting magnetic material defined in this manner, the cutting distance is shorter than when multiple magnetic materials are stacked in the thickness direction and then cut, and cutting processing can be performed efficiently on magnetic materials with arc-shaped cross sections.

[0010] Here, the magnetic material can be cut in a state where the magnetic material fixing tool and the cutting blade are rotated in opposite directions. This can prevent cracks and the like from occurring during cutting.

[0011] In the present invention, the material holding part includes the columnar portion, leg portions protruding radially outward from an outer circumferential surface of the columnar portion, and opposing pieces protruding in a circumferential direction at tip ends of the legs spaced apart from the outer circumferential surface and opposing the magnetic material; a moving means for moving the magnetic material or the opposing piece in a radial direction; using the fixture for a magnetic material comprising: The magnetic material can be fixed by being pressed against the outer circumferential surface of the cylindrical portion or the opposing piece. By doing so, an adhesive for fixing the magnet material to the fixture is not required, and the steps required for applying, curing and removing the adhesive can be omitted.

[0012] In this case, a circumscribing member including the leg portion and the facing piece and movable in the radial direction of the columnar portion; a pair of cylindrical members that abut against one end side and the other end side of the circumscribing member, respectively, to restrict axial movement of the circumscribing member; an inclined surface formed at a contact portion between the cylindrical member and the circumferential member, the inclined surface inclining at a predetermined inclination angle in a direction approaching the axial center of the cylindrical member as it extends radially outward of the cylindrical member; using the fixture for a magnetic material comprising: By moving the pair of cylindrical members in a direction in which the axial distance between them becomes smaller, the opposing pieces of the circumscribing member are moved in a diameter-reducing direction, and the magnetic material can be pressed and fixed against the outer peripheral surface of the cylindrical portion.

[0013] the material holding portion in which the external contact members having the legs and the opposing pieces and the spacers are alternately arranged along the axial direction; an elastic member interposed between the external contact member and the spacer so that a gap is formed between the external contact member and the spacer adjacent to each other when no axial force is applied; a pair of stopper members arranged on both axial sides of the material holding portion, respectively, to restrict the axial length of the material holding portion; using the fixture for a magnetic material comprising: By moving the stopper member in the direction in which the gap becomes smaller, the elastic member expands radially outward, thereby moving the magnetic material in the radially expanding direction and pressing the magnetic material against the opposing piece to fix it. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1A is a perspective view of a magnetic material to which the cutting method of the present invention is applied, and FIG. 1B is a perspective view of a circular arc-shaped magnet cut out from the magnetic material of FIG. [Figure 2] FIG. 2 is a diagram showing a fixing tool for a magnetic material used in the cutting method according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a diagram schematically illustrating a state in which the magnetic material fixture of FIG. 2 is attached to a cutting device. [Figure 4] 10A and 10B are diagrams showing cutting distances in the cutting method of the embodiment; [Figure 5] FIG. 10 is a diagram showing a fixing tool for a magnetic material used in a cutting method according to a second embodiment of the present invention. [Figure 6] FIG. 6 is an exploded perspective view showing the main elements of the fixture for a magnetic material in FIG. 5. [Figure 7] 6(A) is a cross-sectional view of the fixture for a magnetic material in FIG. 5, and (B) is a cross-sectional view taken along the line BB of (A). [Figure 8] 5A to 5C are diagrams showing steps in the cutting method of the embodiment. [Figure 9] FIG. 10 is a perspective view of a fixing tool for a magnetic material used in a cutting method according to a third embodiment of the present invention. [Figure 10] 1A is a side view of a partially cutaway view of a fixture for a magnetic material when no axial force is acting on a material holding portion, and FIG. 1B is a cross-sectional view of the fixture for a magnetic material. [Figure 11] FIG. 10 is a view showing the circumscribing member, spacer, and O-ring of the fixture for magnetic material of FIG. 9 separated from each other. [Figure 12] 10(A) is a side view showing a part of the fixture for a magnetic material in FIG. 9 cut away, and FIG. 10(B) is a cross-sectional view of the fixture for a magnetic material. [Figure 13] 5A to 5C are diagrams showing steps in the cutting method of the embodiment. [Figure 14] FIG. 10 is a diagram showing cutting distances in a cutting method of a comparative example different from the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Next, an embodiment of the present invention will be described in detail with reference to the drawings. 1(A) is a perspective view of a magnetic material to which the cutting method of the present invention is applied. In the figure, S is a magnetic material made of a rare earth-iron-boron alloy, which has been formed into a plate shape by hot working such as hot extrusion. The magnetic material S has an arc-shaped cross section with a width dimension W and a height dimension H, and has a concave inner curved surface 2 and a convex outer curved surface 4. The magnetic material S extends a length dimension L in a direction perpendicular to the cross section while maintaining the cross-sectional shape. In the cutting method of this example, the magnetic material S is cut at the locations indicated by dotted lines in the figure, and a plurality of arc-shaped magnets S1 (two in this example) each having a length dimension L1 as shown in FIG. 1(B) are cut out from the magnetic material S.

[0016] Fig. 2 is a diagram showing a magnetic material fixing tool 10 used in the cutting method of this example. Fig. 2 shows the magnetic material fixing tool (hereinafter, may be simply referred to as a fixing tool) 10 in a state in which the magnetic material S is fixed. The fixture 10 includes a cylindrical portion 12 as a material holding portion 11 that holds the magnetic material S in a fixed state, and end shafts 14 and 15 that extend coaxially from both ends of the cylindrical portion 12, respectively. The cylindrical portion 12 has an axial length longer than the length L of the magnetic material S, and the radius of curvature of the outer circumferential surface 13 of the cylindrical portion 12 is the same as the radius of curvature of the inner curved surface 2 of the magnetic material S.

[0017] In the cutting method of this example, the concave curved surface 2 of the magnetic material S is aligned with the convex outer peripheral surface 13 of the cylindrical portion 12, and the magnetic material S is fixed to the outer peripheral surface 13 of the cylindrical portion 12 so that the longitudinal direction of the magnetic material S coincides with the axial direction of the cylindrical portion 12.

[0018] Six magnetic materials S are fixed to the fixture 10, and are fixed one by one at 60-degree intervals in the circumferential direction to the outer circumferential surface 13. The magnetic materials S can be fixed to the cylindrical portion 12 using an adhesive 17 (for example, Shift Wax manufactured by Nikka Seiko).

[0019] Next, the fixture 10 to which the magnetic material S is fixed is attached to the cutting device 20. Fig. 3 is a diagram schematically showing a state in which the fixture 10 is attached to the cutting device 20. As shown in the figure, the fixture 10 is rotatably attached to the cutting device 20 in such a manner that one end shaft 14 of the fixture 10 is supported by a chuck 21 and the other end shaft 15 is supported by a vibration rest 22.

[0020] As shown in Fig. 3, a cutting blade block body 25 is attached at a position opposite the fixture 10. A plurality of (three in this example) disk-shaped cutting blades 26 are attached to the cutting blade block body 25 coaxially around a rotation shaft 28 via spacers 27. The interval between adjacent cutting blades 26 defined by the spacers 27 corresponds to the dimension L1 of the arc-shaped magnet S1 shown in Fig. 1(B).

[0021] The cutting blade 26 is a thin, disc-shaped base plate with abrasive grains fixed to the outer periphery thereof. The outer diameter of the base plate is, for example, φ80 to 250 mm, and the thickness of the base plate is, for example, 0.1 to 1.4 mm. The abrasive grains covering the outer periphery of the base plate may be diamond abrasive grains or CBN abrasive grains.

[0022] Then, while both the opposing fixture 10 and cutting blade block body 25 are rotated, the cutting blade block body 25 is moved relatively toward the fixture 10, and the cutting blade 26 cuts from the outer circumferential surface side toward the inside of the magnetic material S to perform the cutting process. Note that a cutting fluid supply nozzle (not shown) is provided near the cutting portion, and cutting fluid is continuously supplied to the cutting process point on the magnetic material S.

[0023] 3 and 4, in this example, cutting is performed with the magnetic material fixing tool 10 and the cutting blade 26 rotating in opposite directions. This is because this is effective in suppressing cracking of the magnetic material S during the cutting process. The rotation speeds of each tool can be set appropriately, but examples of the rotation speed of the fixing tool 10 attached to the cutting device 20 can be 60 to 120 rotations per minute, and the rotation speed of the cutting blade 26 can be 5,000 to 7,000 rotations per minute.

[0024] After cutting is complete, the fixture 10 is removed from the cutting device 20, and the adhesive is melted and removed in a heating chamber heated to a predetermined temperature, allowing the arc-shaped magnet S1 cut to the specified size to be removed from the fixture 10. In this example, 12 arc-shaped magnets S1 can be obtained in one cutting process.

[0025] In the cutting method of the present embodiment as described above, as shown in FIG. 4(A), when the cutting blade 26 is disposed above the fixing tool 10 and the magnetic material S is cut with the top of the rotating fixing tool 10 as the cutting processing point, the cutting distance is K3.

[0026] 4(B), when cutting blade 26 is positioned so that its rotation center O1 is on a horizontal line passing through rotation center O2 of fixing device 10, and cutting blade 26 is moved horizontally, the cutting distance is K4. In both cases of FIG. 4(A) and FIG. 4(B), the cutting distance can be significantly shorter than when cutting is performed by stacking multiple magnet materials in the thickness direction, as shown in FIG.

[0027] Furthermore, according to the cutting method of the present embodiment, the magnetic material S is fixed in a manner such that the concave curved surface 2 of the magnetic material S is aligned with the convex outer peripheral surface 13 of the cylindrical portion 12. Therefore, a gap is less likely to occur between the mounting surface (outer peripheral surface 13) and the magnetic material S compared to a case in which an arc-shaped magnetic material is fixed on a flat mounting surface, and cracks caused by the gap can be suppressed.

[0028] Next, a cutting method according to a second embodiment of the present invention will be described. This cutting method makes it possible to fix a magnetic material to a fixture for magnetic material without using an adhesive and perform cutting processing. As shown in Figs. 5 to 8, the magnetic material fixing device 10B used in this embodiment includes, as components of the material holding part 11, a cylindrical part 12 and an external contacting member 31 that protrudes from the outer circumferential surface 13 of the cylindrical part 12 and can come into contact with the magnetic material S from the side of the outer surface 4 (see Fig. 1(A)) of the magnetic material S.

[0029] 6, a plurality of (six in this example) grooves 39 are formed radially at predetermined intervals in the circumferential direction in the columnar portion 12, extending from one end 12a to the other end 12b and opening on the outer circumferential surface 13. A part of a circumscribing member 31 separate from the columnar portion 12 is inserted into the grooves 39, and the circumscribing member 31 is held in a state where it cannot move in the circumferential direction of the columnar portion 12 but can move in the radial direction of the columnar portion 12. On the other end 12b side of the outer peripheral surface 13 of the cylindrical portion 12, protruding pieces 18 are formed in the respective regions defined by the grooves 39. The protruding pieces 18 are positioning pieces that come into contact with the end face of the magnetic material S to define the position of the magnetic material S in the axial direction.

[0030] As shown in FIG. 6, the external contact member 31 includes a leg portion 43 and an opposing piece 45 . The leg portion 43 is a plate-like member having approximately the same length as the columnar portion 12. The leg portion 43 has two end portions 43a, 43a that are low in height when viewed from the side, and a central portion 43b that is high in height. An inclined surface 44 is formed on the upper surface of the portion between the end portion 43a and the central portion 43b.

[0031] The lower parts of the leg parts 43 including the end parts 43 a, 43 a are housed in the grooves 39, while the tip side of the higher central part 43 b protrudes from the outer circumferential surface 13 of the columnar part 12, and an opposing piece 45 is formed on the tip side of the central part 43 b, protruding in the circumferential direction and opposing the magnetic material S. The cross-sectional shape of the part of the external contact member 31 that has the opposing piece 45 is approximately T-shaped.

[0032] As shown in FIG. 7(A), the circumscribing member 31 is inserted into each of a plurality of (six in this example) grooves 39 formed in the cylindrical portion 12, and a space 40 defined by the outer circumscribing surface 13 and the circumscribing member 31 is formed around the cylindrical portion 12, and the magnetic material S is accommodated in this space 40.

[0033] Cylindrical members 34 and 35 and nut members 36 and 37 are provided on one end and the other end of the material holding portion 11, respectively. The tubular members 34, 35 have a stepped cylindrical shape and include a large diameter portion 48 and a small diameter portion 49. After the end shafts 14, 15 are inserted into the tubular members 34, 35, the large diameter portion 48 is attached so as to fit over the end of the columnar portion 12 and the external contact member 31, respectively. The end 48a of the large diameter portion 48 abuts against the leg portion 43 of the external contact member 31, restricting axial movement of the external contact member 31.

[0034] As shown in the enlarged partial view of FIG. 7(B), an inclined surface 44 on the leg 43 side and an inclined surface 50 on the large diameter portion 48 side are formed at the contact portion between the end 48a of the large diameter portion 48 and the leg 43 of the circumscribing member 31. These inclined surfaces 44, 50 are inclined at a predetermined inclination angle θ in a direction approaching the axial center of the cylindrical portion 12 as they move radially outward of the cylindrical portion 12. The inclined surfaces 44, 50 convert the axial moving force of the cylindrical member 34 (to the right in the partial enlarged view) into a radial moving force of the circumscribing member 31 (downward in the view). That is, in this example, the pair of cylindrical members 34, 35 and the inclined surfaces 44, 45 provided at the contact portion constitute a moving means for moving the circumscribing member 31, including the opposing piece 45, in the radial direction.

[0035] The nut members 36, 37 are provided on the opposite side of the cylindrical members 34, 35 from the material holding portion 11, and are threadedly engaged with the male thread portions 16 formed on the end shafts 14, 15. The nut members 36, 37 come into contact with the small diameter portions 49 of the cylindrical members 34, 35, respectively, and are capable of moving the cylindrical members 34, 35 in the axial direction by a screw feed action. In this example, both tubular members 34 and 35 are movable in the axial direction, but it is also possible to adopt a configuration in which, for example, one of the tubular members 35 is made immovable in the axial direction, and only the tubular member 34 is moved in the axial direction based on the screw feed action of the nut member 36.

[0036] Next, a cutting method of this example using the fixing tool 10B for a magnetic material will be described. First, as shown in FIG. 8(I), with one of the cylindrical members 34 removed, the magnetic material S is accommodated in the space 40 formed by inserting the circumscribing member 31 into the groove 39 of the columnar portion 12, and then the cylindrical member 34 is fitted onto the ends of the columnar portion 12 and the circumscribing member 31. Next, the nut members 36, 37 (see FIG. 7 ) are tightened, and as shown in FIG. 8(II), when the tubular members 34, 35 are moved in a direction in which the axial distance between the pair of tubular members 34, 35 decreases, the opposing piece 45 of the extrinsic member 31 moves in the diameter-reducing direction (downward in the figure), and the magnetic material S is pressed against the outer circumferential surface 13 of the cylindrical portion 12, thereby fixing the magnetic material S. Although FIG. 8(II) shows a state in which one magnetic material S is fixed, the tubular members 34, 35 are in contact with all (six) of the extrinsic members 31 attached to the cylindrical portion 12, and all of the extrinsic members 31 move simultaneously in the diameter-reducing direction, and all (six) of the magnetic materials S are fixed.

[0037] Next, the fixture 10B to which the magnetic material S is fixed is attached to the cutting device 20. Then, while both the fixture 10B and the cutting blade block body 25 (see FIG. 3) are rotated, the cutting blade block body 25 is moved relatively toward the fixture 10B (magnetic material S), and the cutting blade 26 is caused to cut into the magnetic material S from the outer circumferential surface side toward the inside (see FIG. 8(III)). 8(IV) shows fixture 10B after cutting is complete. After cutting is complete, arc-shaped magnet S1 cut to the specified dimensions can be removed from fixture 10B by loosening nut members 36 and 37.

[0038] As described above, according to the cutting method of the present embodiment, not only can the cutting distance be shortened, but also the magnetic material S can be fixed to the fixing tool 10B without using an adhesive. Therefore, the cutting method of the present embodiment does not require the steps of applying the adhesive and heating and curing the adhesive, which are required when using an adhesive, as well as the cleaning step of removing the adhesive after cutting, and therefore the steps required to cut the magnetic material can be simplified.

[0039] Next, a cutting method according to a third embodiment of the present invention will be described with reference to Fig. 9 to Fig. 13. In this example as well, it is possible to fix the magnetic material to the fixing tool for magnetic material without using an adhesive and then perform the cutting process. In the fixing tool 10C for magnetic material used in this example, as shown in FIG. 10(A), a plurality of external contact members 61 and spacers 71 are alternately arranged along the axial direction to form a material holding part 11 that holds the magnetic material S in a fixed state.

[0040] 11, the circumscribing member 61 is a ring-shaped member having legs 43 protruding at equal intervals in the circumferential direction from an outer peripheral surface 64 on the radially outer side, and opposing pieces 45 protruding in the circumferential direction and opposing the magnetic material S formed on the tip sides of the legs 43. The magnetic material S is accommodated in a space 65 (see FIG. 10(B)) defined by the outer peripheral surface 64 of the circumscribing member 61, the legs 43, and the opposing pieces 45. A through hole 62 is formed in the center of the circumscribing member 61, through which the shaft body 58 is inserted. Here, the shaft body 58 is a member integrally comprising the end shafts 14, 15 and flange 59 shown in Figure 10(A), and is provided with a key 58a at the portion that fits with the circumscribing member 61 and spacer 71. A key groove 62a that can fit with this key 58a is formed in the through hole 62 of the circumscribing member 61, and the circumferential positions of the multiple circumscribing members 61 arranged in the axial direction are aligned.

[0041] As shown in FIG. 11, the spacer 71 is also a ring-shaped member, and has a through-hole 72 formed in the center thereof for inserting the shaft body 58 therethrough. Meanwhile, notches 77 and 78 are formed by cutting out the corners where the radially outer outer peripheral surface 64 intersects with the end faces 75 and 76. An O-ring 81 with a circular cross section serving as an elastic member is fitted in each of the notches 77 and 78.

[0042] As shown in the partially enlarged view of FIG. 10(A), the size (diameter) of the O-ring 81 is specified so that a gap δ is formed between the adjacent external contact members 61 and spacers 71 when no axial force is acting on the external contact members 61 and spacers 71 that constitute the material holding part 11.

[0043] A pair of stopper members 84, 85, which are formed separately from the shaft body 58 and are axially movable along the shaft body 58, are disposed on both axial sides of the material holding part 11. The stopper members 84, 85 come into contact with the end faces of the material holding part 11 to restrict the axial length of the material holding part 11. In this example, by moving the stopper members 84, 85 in the direction in which the gap δ becomes smaller, the O-ring 81 is compressed in the axial direction, and as shown in the partial enlarged view of Fig. 12(A), the O-ring 81 is caused to bulge outward in the radial direction, thereby allowing the magnetic material S to move in the radial expansion direction (upward in the partial enlarged view). That is, in this example, the pair of stopper members 84, 85 and the O-ring 81 arranged in the material holding part 11 constitute a moving means for moving the magnetic material S in the radial direction.

[0044] The nut member 88 is provided on the opposite side of the stopper member 84 from the material holding portion 11, and is threaded onto the male thread portion 16 formed on the shaft body 58. The nut member 88 has a flange portion 89, and is capable of moving the stopper member 84 in the axial direction (to the right in the drawing) by further screw feeding action from a state in which the nut member 88 is in contact with the stopper member 84. The other stopper member 85 is in contact with a flange 59 formed integrally with the shaft body 58, and its movement in the axial direction (to the right in the drawing) is restricted.

[0045] Next, a cutting method of this example using the fixture 10C for magnetic material will be described. First, as shown in FIG. 13(I), in the fastener 10C for magnetic material, in which no axial force is acting on the material holding part 11 and a gap δ is formed, the magnetic material S is accommodated in the space 65 formed in the material holding part 11.

[0046] Next, when the nut member 88 is rotated in the tightening direction and the stopper member 84 is moved in the direction in which the gap δ becomes smaller (to the right in the figure) as shown in FIG. 13(II), the O-ring 81 is compressed in the axial direction and the O-ring 81 bulges outward in the radial direction (see the partially enlarged view in FIG. 12(A)). As a result, the magnetic material S moves in the radially expanding direction and is pressed against and fixed to the opposing piece 45.

[0047] Next, the fixture 10C to which the magnetic material S is fixed is attached to the cutting device 20. Then, while both the fixture 10C and the cutting blade block body 25 (see FIG. 3) are rotated, the cutting blade block body 25 is moved relatively toward the fixture 10C (magnetic material S), and the cutting blade 26 is caused to cut into the magnetic material S from the outer circumferential surface side toward the inside (see FIG. 13(III)). After cutting is complete, the nut member 88 is loosened, and the arc-shaped magnet S1 cut to a predetermined size can be removed from the fixture 10C.

[0048] As described above, also in the cutting method of this embodiment, the cutting distance can be shortened and the magnetic material S can be fixed to the fixing tool 10C without using an adhesive.

[0049] Although the embodiments of the present invention have been described in detail above, these are merely examples. For example, the size of the cylindrical portion and the shape of the opposing pieces of the magnetic material fixture used in the present invention can be changed as appropriate to match the size and shape of the magnetic material to be held. Furthermore, the present invention can be applied to cutting magnetic materials made of metal magnets other than rare earth magnets, and various other modifications can be made to the present invention without departing from the spirit of the present invention. [Explanation of symbols]

[0050] 2 Inner curved surface 10,10B,10C Fixture for magnetic material 11 Material holding section 12 Cylindrical part 13 Outer surface 26 Cutting blade 31 Circumscribed members 34,35 Cylindrical member 43 Legs 44,50 Slope 45 Opposing piece 61 Circumscribed members 71 Spacer 81 O-ring (elastic member) 84, 85 Stopper member S magnet material

Claims

1. A method for cutting a magnetic blank having a cross-sectional shape of an arc and extending in a direction perpendicular to the cross-section, comprising: a material holding portion configured to hold the magnetic material in a fixed state, the material holding portion including: a cylindrical portion; leg portions protruding radially outward from an outer circumferential surface of the cylindrical portion; and opposing pieces protruding in the circumferential direction at tip ends of the legs spaced from the outer circumferential surface and opposing the magnetic material; a moving means for moving the magnetic material or the opposing piece in a radial direction; A magnetic material fixture equipped with pressing the magnetic material against the outer peripheral surface of the cylindrical portion or the opposing piece in such a manner that the concave curved surface of the magnetic material is aligned with the convex outer peripheral surface of the cylindrical portion, and fixing a plurality of the magnetic materials in a circumferential direction of the cylindrical portion; a magnetic material cutting method, comprising: rotating the magnetic material fastener having the magnetic material fixed thereto and a disk-shaped cutting blade together; and moving the cutting blade relatively toward the magnetic material to cut the magnetic material fixed to the magnetic material fastener.

2. 2. The method for cutting a magnetic material according to claim 1, wherein the magnetic material is cut in a state in which the magnetic material fixing tool and the cutting blade are rotated in opposite directions.

3. a circumscribing member including the leg portion and the opposing piece and movable in a radial direction of the columnar portion; a pair of cylindrical members that abut against one end side and the other end side of the circumscribing member, respectively, to restrict axial movement of the circumscribing member; an inclined surface formed at a contact portion between the cylindrical member and the circumferential member, the inclined surface inclining at a predetermined inclination angle in a direction approaching the axial center of the cylindrical member as it extends radially outward of the cylindrical member; using the fixture for a magnetic material comprising:

2. The method for cutting a magnetic material according to claim 1, wherein the opposing pieces of the circumferential member are moved in a diameter-reducing direction by moving the pair of cylindrical members in a direction in which the axial distance between the cylindrical members becomes smaller, and the magnetic material is pressed against and fixed to an outer peripheral surface of the columnar portion.

4. the material holding portion in which circumferential members having the legs and the opposing pieces and spacers are alternately arranged along the axial direction; an elastic member interposed between the external contact member and the spacer so that a gap is formed between the external contact member and the spacer adjacent to each other when no axial force is applied; a pair of stopper members arranged on both axial sides of the material holding portion, respectively, to restrict the axial length of the material holding portion; using the fixture for a magnetic material comprising:

2. The method for cutting a magnetic material according to claim 1, wherein the movement of the stopper member in the direction in which the gap becomes smaller causes the elastic member to bulge radially outward, thereby moving the magnetic material in a radially expanding direction and pressing and fixing the magnetic material against the opposing piece.

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