Method for producing highly anisotropic magnet, method for producing magnet assembly, highly anisotropic magnet, magnet assembly, and composite magnet assembly

Abstract

To provide a method for producing a highly anisotropic magnet and a method for producing a magnet assembly that offer higher design flexibility and improved economic efficiency, compared with existing techniques.SOLUTION: The method for producing a highly anisotropic magnet having four surfaces SF1, SF2, SF3, and SF4 includes: a magnetic-field forming step S20 in which a magnetic field in a first direction is applied to one effective surface VSF (SF1) among the four surfaces and magnetic fields in a second direction are respectively applied to the remaining three surfaces SF2, SF3, and SF4 while performing in-field molding; and a four-side magnetizing step S40 in which the magnetic field in the first direction is applied to the effective surface VSF (SF1) and the magnetic fields in the second direction are applied to the remaining three surfaces SF2, SF3, and SF4 to perform magnetization.SELECTED DRAWING: Figure 17

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a polar anisotropic magnet, a method for manufacturing a magnet assembly, a polar anisotropic magnet, a magnet assembly, and a composite magnet assembly. [Background technology]

[0002] It is known that magnet assemblies configured in a so-called Halbach array can generate magnetic flux at high magnetic flux densities. However, realizing this Halbach array poses many challenges, as strongly magnetized magnets must be bonded together under conditions where large attractive and repulsive forces are generated. For this reason, mass production is not yet in sight.

[0003] A magnet assembly having the configuration shown in FIG. 3 of Patent Document 1 (hereinafter simply referred to as the magnet assembly described in Patent Document 1) is known as an alternative technology that can obtain a magnetic flux density at the same level as the Halbach array and has the potential for mass production.

[0004] 30 is a cross-sectional view shown for explaining a magnet assembly 900 described in Patent Document 1. The arrows drawn inside the magnet assembly 900 indicate the magnetization direction. As shown in FIG. 30, the magnet assembly 900 is composed of a cylindrical outer-side magnet assembly 900EX and an inner-side magnet assembly 900IN. The outer-side magnet assembly 900EX has a polar anisotropic arrangement in which the magnetization direction is tilted at an angle θHEX with respect to the normal NL of the magnet assembly 900EX. The angle θHEX is greater than 45 degrees and close to 90 degrees. In other words, the magnet assembly has a "horizontal polar anisotropic arrangement" in which the magnetization direction forms a relatively shallow angle with the tangent to the outer peripheral surface (not shown). On the other hand, the inner-side magnet assembly 900IN has a polar anisotropic arrangement in which the magnetization direction is tilted at an angle θHIN with respect to the normal NL. The angle θHIN is greater than 0 degrees and less than 45 degrees. In other words, the magnet assembly has a "vertical polar anisotropic arrangement" in which the magnetization direction forms a relatively deep angle with the tangent to the inner peripheral surface (not shown).

[0005] This magnet assembly 900 was obtained by separately manufacturing an outer circumferential magnet assembly 900EX (also called a cylindrical body 900EX) and an inner circumferential magnet assembly 900IN (also called a cylindrical body 900IN), and then fitting these cylindrical bodies together to form a single body.

[0006] Because the manufacturing methods for the outer peripheral side magnet assembly 900EX and the inner peripheral side magnet assembly 900IN are basically the same, the manufacturing of the outer peripheral side cylindrical body 900EX will be described here as a representative example. Figure 31 is a diagram shown to explain a conventional manufacturing method for the magnet assembly 900EX. In Figure 31, (1) shows the mold 810 and magnetic sources 820S, 820N used in the magnetic field molding step, (2) shows the magnet mother material M1, (3) shows the magnetizing step, and (4) shows the magnet assembly 900EX removed after the magnetizing step.

[0007] A conventional method for manufacturing a magnet assembly is roughly as follows. First, powder material for magnets, a mold 810, etc. are prepared. The mold 810 is formed into a cylindrical shape whose inside shape follows the shape of the final magnet assembly 900EX. Next, a magnetic field molding process is performed. Powder material is placed inside 810a of mold 810, and then a predetermined magnetic field is applied from outside mold 810 using magnetic sources 820S and 820N, orienting the molecules of the powder material along the magnetic field lines while molding (see (1) in Figure 31). This produces magnetic base material M1 (see (2) in Figure 31). After that, after necessary intermediate processes (sintering, heat treatment, surface treatment, etc.), a magnetization process is performed in which a predetermined magnetic field is applied using magnetic sources 830S and 830N (such as a magnetizing yoke) (see (3) in Figure 31). This produces magnet assembly 900EX (see (4) in Figure 31). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-142082 Summary of the Invention [Problem to be solved by the invention]

[0009] However, as described below, conventional methods for manufacturing magnet assemblies have had problems such as low economic efficiency due to high costs and low mass productivity (e.g., low yield), as well as many design constraints.

[0010] For example, the mold 810 used in the magnetic field molding process must be prepared in a shape that matches the shape of the final magnet assembly every time the product specifications change, which increases the cost of the mold and leads to higher overall costs (mold cost issue).

[0011] Furthermore, if the radial thickness of the outer magnet assembly 900EX is designed to be small and relatively thin, breakage may occur during the sintering and heat treatment processes after the magnetic field molding process, resulting in a drop in yield (breakage problem).

[0012] In order to prevent such damage, the outer magnet assembly 900EX must be set to a thickness larger than that necessary and sufficient to achieve the expected performance (a design margin must be added), which reduces the radial thickness of the inner magnet assembly 900IN.As a result, the desired ratio between the thickness of the horizontal polar anisotropic array and the thickness of the vertical radial anisotropic array cannot be obtained, and ultimately, there are cases where the desired magnetic characteristics cannot be obtained.

[0013] Furthermore, when attempting to change the dimensional specifications of the magnet assembly, such as the radial thickness or outer diameter, due to a model change or the like, problems such as a decrease in yield or an inability to ensure the required magnetic properties may occur.

[0014] As shown in Figure 32(a), when the design allows for sufficient radial thickness of the magnet assembly (see thickness T1), the orientation of the powder after the compaction process in the magnetic field can be ensured at a reasonable angle with respect to the outer periphery near where the magnetic field lines are emitted to the outside (an angle relatively close to the normal NL), and the orientation of the powder becomes the magnetization direction when the magnetization process is performed, ultimately resulting in a polar-anisotropic magnet assembly with the desired magnetic properties. However, as shown in Figure 32(b), when the design requires a thin radial thickness (see thickness T2), the orientation of the powder can only be ensured at a shallow angle with respect to the outer periphery (an angle nearly 90 degrees with respect to the normal NL), which results in the magnetic field lines not being emitted to the outside with the intended strength, and ultimately results in the magnetic properties required for the product not being achieved. In other words, prioritizing thinning the thickness of the magnet assembly would take away freedom in designing the orientation direction (magnetization direction), and prioritizing the orientation direction (magnetization direction) would take away freedom in designing the thickness of the magnet assembly.

[0015] Furthermore, conventionally, there have been many problems in terms of mass production when obtaining polar anisotropic magnets that make up part of the magnet assembly on the outer periphery (for example, the polar anisotropic magnets in the area surrounded by dashed line C in FIG. 30). If the magnets were assembled in a magnetized state, the magnets 905 and 906, which are magnetized in a roughly horizontal direction, would be joined by butting together faces with the same magnetic poles, and since the joining would involve a large repulsive force being generated between them, mass production would be difficult (the same applies to the polar anisotropic magnets made up of magnets 907 and 908 within dashed line D).

[0016] Incidentally, if the base materials are pre-magnetized before they become magnet 905 or magnet 906 (let's call them base materials 905' and 906' (not shown)), joining is easy because no repulsion occurs between base materials 905' and 906'. However, no magnetization method has been established for the subsequent magnetization process, and it has ultimately been difficult to mass-produce the polar anisotropic magnets shown by dashed lines D and C in Figure 30.

[0017] The present invention has been made in consideration of the above circumstances, and has an object to provide a method for manufacturing a polar-anisotropic magnet and a magnet assembly that offers greater design freedom and is more economical than conventional methods, as well as a polar-anisotropic magnet, a magnet assembly, and a composite magnet assembly. [Means for solving the problem]

[0018] According to one aspect of the present invention, there is provided a method for manufacturing a polar-anisotropic magnet having four surfaces facing in four directions when viewed in cross section. The method for manufacturing a polar-anisotropic magnet includes, in this order: a powder material preparation step for preparing powder material for the magnet; a magnetic field molding step for sequentially pouring the powder material into a mold corresponding to the desired shape of the polar-anisotropic magnet, where the surface on which magnetic flux should be concentrated is defined as the effective surface, while applying a magnetic field in a first direction to the imaginary effective surface and a magnetic field in a second direction to the remaining three surfaces, while molding a magnetic base material having a shape that matches the shape of the mold; and a four-directional magnetization step for magnetizing the magnetic material obtained from the magnetic base material by surrounding the effective surface of the magnetic material and applying a magnetic field in the first direction to the effective surface of the magnetic material and a magnetic field in the second direction to the remaining three surfaces.

[0019] Furthermore, the polar anisotropic magnet of the present invention is a polar anisotropic magnet that has four faces facing four directions when viewed in cross section, and when the face of the four faces on which magnetic flux should be generated in a concentrated manner is considered to be the effective face, one magnetic pole is arranged on the effective face, and other magnetic poles are arranged on each of the remaining three faces other than the effective face, and when viewed in cross section, there are no adhesive marks inside and the magnet is formed continuously.

[0020] Furthermore, the magnet assembly of the present invention comprises a plurality of the above-described polar anisotropic magnets, which are arranged and joined together so that one magnetic pole and the other magnetic pole appear alternately.

[0021] According to another aspect of the present invention, there is provided a method for manufacturing a cylindrical magnet assembly. The manufacturing method of the magnet assembly comprises a powder material preparation step of preparing powder material for the magnet, and a magnetic field molding step of molding a "magnet base material" having a first main surface and a second main surface opposite the first main surface, in which the powder material is poured into a form corresponding to the shape of the magnet base material, and a magnetic field is applied in a single direction from the side of the form corresponding to the first main surface on the outside of the form to the side corresponding to the second main surface to mold the magnet base material, and a magnetic field molding step of molding the magnet base material by applying a magnetic field in a single direction from the side of the form corresponding to the first main surface on the outside of the form to the side corresponding to the second main surface, in which the surface that will become the outer diameter surface of the magnet assembly when assembled into a magnet assembly is defined as the "planned outer diameter surface" and the surface that will become the inner diameter surface is defined as the "planned inner diameter surface," The cutting process includes, in this order, a cutting process of cutting the magnet base material along the cutting line of the planned outer diameter surface, setting the cutting line of the planned inner diameter surface to be inclined at an angle θ1 relative to the first main surface, and cutting the magnet base material along the cutting line of the planned inner diameter surface, setting the cutting line of the planned inner diameter surface to be inclined at an angle θ2 relative to the first main surface, to cut out magnet base material pieces having at least the planned outer diameter surface and the planned inner diameter surface on their outer surfaces; an assembling process of combining multiple magnet base material pieces together to assemble a magnet base material assembly; and a magnetizing process of magnetizing the magnet base material assembly by applying a predetermined magnetic field from outside the magnet base material assembly at a predetermined position.

[0022] The magnet assembly of the present invention has substantially flat outer and inner diameter surfaces, and comprises magnet blocks that are magnetized in a single direction parallel to the outer and inner diameter surfaces at a predetermined angle, and the magnet blocks are joined to each other via surfaces other than the outer and inner diameter surfaces.

[0023] Furthermore, the composite magnet assembly of the present invention comprises the above-mentioned magnet assembly of the first aspect in which the angle of the magnetization direction relative to the outer diameter surface and inner diameter surface of each magnet block is a first angle, and the above-mentioned magnet assembly of the second aspect in which the angle of the magnetization direction relative to the outer diameter surface and inner diameter surface of each magnet block is a second angle that is different from the first angle. In the composite magnet assembly, the magnet assembly of the first aspect is arranged on the side that should be the effective H magnetic flux surface of the composite magnet assembly, and the magnet assembly of the second aspect is arranged on the side that should be the effective V magnetic flux surface of the composite magnet assembly, and they are joined together.

[0024] According to yet another aspect of the present invention, there is provided a method for manufacturing a polar anisotropic magnet having four faces when viewed in cross section. The manufacturing method of polar anisotropic magnets comprises a powder material preparation step of preparing powder material for the magnet, a magnetic field molding step of molding a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, in which the powder material is poured into a form corresponding to the shape of the magnet base material, and a magnetic field molding step of applying a unidirectional parallel magnetic field from the side corresponding to the first main surface on the outside of the form to the side corresponding to the second main surface to mold the magnet base material, and a magnetic field molding step of molding the magnet base material when the polar anisotropic magnets are assembled into a magnet assembly. When the surface that is to become the outer diameter surface of the assembly is defined as the "planned outer diameter surface" and the surface that is to become the inner diameter surface is defined as the "planned inner diameter surface," the cutting line of the planned outer diameter surface is set to be inclined at an angle θ1 with respect to the first main surface, and the magnet base material is cut along the cutting line of the planned outer diameter surface, and the cutting line of the planned inner diameter surface is set to be inclined at an angle θ2 with respect to the first main surface, and the magnet base material is cut along the cutting line of the planned inner diameter surface, to produce a magnet base material piece having at least the planned outer diameter surface and the planned inner diameter surface on its outer surfaces. a sub-assembly process for assembling at least four magnet base material pieces to form a magnet base material subassembly having four surfaces, in which, when the surface of the four surfaces where magnetic flux should be generated intensively is defined as the effective surface, horizontal magnet base material pieces cut at angles θ1 and θ2 in the cutting process that are each set within the range of more than 45 degrees and less than 90 degrees are placed on the side that will become the effective surface of the magnet base material subassembly, and vertical magnet base material pieces cut at angles θ1 and θ2 in the cutting process that are each set within the range of more than 0 degrees and less than 45 degrees are placed on the side opposite to the side that will become the effective surface; and a four-directional magnetization process for surrounding the magnet base material subassembly and applying a magnetic field in a first direction to the effective surface of the magnet base material subassembly and a magnetic field in a second direction to the remaining three surfaces to magnetize the magnet base material subassembly.

[0025] The above configuration provides a method for manufacturing a polar anisotropic magnet and a method for manufacturing a magnet assembly that offer greater design freedom and are more economical than conventional methods. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a cross-sectional view illustrating an example of a magnet assembly 100. [Figure 2] FIG. 2 is a cross-sectional view showing the state of pre-magnetized material 5 before it is magnetized to become polar anisotropic magnets 1N and 1S. [Figure 3] 1A and 1B are diagrams illustrating an example of polar anisotropic magnets 1N and 1S. [Figure 4] 10A and 10B are diagrams shown to explain another example of polar anisotropic magnets 1N and 1S. [Figure 5] 3 is a flowchart shown to explain the method for manufacturing a polar anisotropic magnet according to the first embodiment. [Figure 6] 10 is a schematic cross-sectional view showing a state in which a magnetic field molding step S20 is carried out. FIG. [Figure 7] FIG. 10 is a schematic diagram of the magnet base material M1 taken out after the in-magnetic-field molding step S20 is performed. [Figure 8] FIG. 10 is a schematic diagram of the magnet material M2 taken out after the processing step S32 is performed. [Figure 9] FIG. 10 is a schematic diagram of the magnet material M2' taken out after the surface treatment step S33 is performed. [Figure 10] FIG. 10 is a schematic cross-sectional view showing a state in which a four-way magnetization step S40 is performed. [Figure 11] 1A and 1B are diagrams shown to explain a magnet assembly 100 according to the first embodiment. [Figure 12] 5A and 5B are diagrams illustrating a motor 510, a generator 520, and an actuator 530 according to an application example. [Figure 13] 10A to 10C are diagrams illustrating a modified example of the method for performing the four-way magnetization step S40. [Figure 14] 10A and 10B are diagrams shown to explain magnet assemblies 110 and 120 according to modified examples. [Figure 15] FIG. 10 is a diagram showing a cylindrical double-structure magnet unit 400 according to a modified example. [Figure 16]FIG. 10 is a diagram showing a linear double-structure magnet unit 420 according to a modified example. [Figure 17] 10 is a flowchart shown to explain a method for manufacturing a magnet assembly according to the second embodiment. [Figure 18] 10A and 10B are diagrams illustrating a magnetic field molding step SS20. [Figure 19] 10A and 10B are diagrams shown to explain a cutting step SS40. [Figure 20] FIG. 10 is a diagram for explaining an assembly process SS60. [Figure 21] 10A to 10C are diagrams illustrating a magnetization step SS70. [Figure 22] 10 is a cross-sectional view showing a cutting step SS40 of the third embodiment. FIG. [Figure 23] 10 is a cross-sectional view illustrating an assembly step SS60 of the third embodiment. FIG. [Figure 24] FIG. 11 is a cross-sectional view of the magnet assembly 100IN after the magnetization step SS70 of the third embodiment has been performed. [Figure 25] 10 is a flowchart shown to explain a method for manufacturing a magnet assembly and a method for manufacturing a polar anisotropic magnet according to a fifth embodiment. [Figure 26] FIG. 10 is a diagram for explaining a sub-assembly process SS80. [Figure 27] FIG. 10 is a diagram illustrating a four-way magnetization step SS85. [Figure 28] FIG. 10 is a schematic diagram for explaining a linear motor structure 550 according to a modified example of the application example. [Figure 29] 10 is a diagram illustrating the details of a linear motor structure 550. FIG. [Figure 30] FIG. 1 is a cross-sectional view shown for explaining a magnet assembly 900 described in Patent Document 1. [Figure 31] 10A and 10B are diagrams shown to explain a conventional manufacturing method for the magnet assembly 900EX. [Figure 32] FIG. 1 is a schematic diagram showing the orientation direction of powder material in a compaction step in a magnetic field according to a conventional manufacturing method. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the manufacturing method for a polar-anisotropic magnet, manufacturing method for a magnet assembly, polar-anisotropic magnet, magnet assembly, and composite magnet assembly according to the present invention will be described with reference to the drawings. Each drawing is a schematic diagram showing an example and does not necessarily strictly reflect actual dimensions, proportions, etc. In Figures 17 to 32, dashed or solid lines drawn inside the magnet base material 10, magnet base material pieces 20, 30, etc. indicate the molecular orientation direction (axis of easy magnetization), and solid lines with arrows drawn inside the magnet assembly or polar-anisotropic magnet indicate the magnetization direction.

[0028] A. Manufacturing method for polar anisotropic magnets by four-directional magnetization First, a manufacturing method for four-directionally magnetizing polar anisotropic magnets, which are elements that make up the magnet assembly, will be disclosed.

[0029] [Embodiment 1] 1. Polar anisotropic magnets 1N and 1S and magnet assembly 100 Before describing the method for manufacturing a polar anisotropic magnet, an example of the polar anisotropic magnets 1N, 1S and magnet assembly 100 (sometimes referred to as a composite magnet assembly) to be manufactured will be described.

[0030] (1) Magnet assembly 100 FIG. 1 is a cross-sectional view shown to explain an example of a magnet assembly 100. In FIG. 1, arrow B drawn inside polar anisotropic magnets 1N, 1S indicates the magnetization direction. The magnet assembly 100 shown in FIG. 1 can produce magnetic properties substantially similar to those of the magnet assembly 900 shown in FIG. 3 of Patent Document 1. In the method for manufacturing a polar anisotropic magnet according to embodiment 1, polar anisotropic magnets 1N, 1S are manufactured in units enclosed by dotted lines in FIG. 1.

[0031] (2) Pre-magnetized material with linear molecular orientation (easy axis of magnetization) Figure 2 is a diagram of a portion corresponding to one unit enclosed by a dotted line in Figure 1, and is a cross-sectional view showing the state of pre-magnetized material 5 before it is magnetized to become polar anisotropic magnets 1N and 1S. The thick solid line drawn inside pre-magnetized material 5 indicates the molecular orientation (axis of easy magnetization). 2, when the inside of the pre-magnetized material 5 is divided into four regions, the molecular orientation (axis of easy magnetization) in each region is linear and parallel to each other. Here, the angle that the molecular orientation (axis of easy magnetization) in the outer diameter region makes with the tangent line TL to the central part of the outer circumferential surface of the pre-magnetized material 5 is defined as θout, and the angle that the molecular orientation (axis of easy magnetization) in the inner diameter region makes with the normal line NL to the central part of the outer circumferential surface of the pre-magnetized material 5 is defined as θin. As one example, a split-ring shaped soft magnetic body 6 can be placed on the inner diameter side of the pre-magnetized material 5. In this case, by setting θin to a value exceeding 0 degrees, the thickness of the soft magnetic body 6 can be reduced. In addition, by appropriately changing the value of θout, it is possible to change the magnetic flux density form of the magnetic lines of force output from the center part of the outer circumferential surface, which is the position indicated as the normal line NL. By magnetizing the pre-magnetization material 5 corresponding to the above-mentioned FIG. 2 by an appropriate method, polar anisotropic magnets 1N and 1S as shown in the following FIG. 3 can be constructed.

[0032] (3) Polar anisotropic magnets 1N, 1S with linear magnetization direction Figure 3 is a diagram used to explain an example of polar anisotropic magnets 1N and 1S. Figures 3(a) and 3(b) show polar anisotropic magnets 1N and 1S, respectively. In Figure 3, arrow B drawn inside polar anisotropic magnets 1N and 1S indicates the magnetization direction. As shown in Figure 3(a), the polar anisotropic magnet 1N has four faces SF1, SF2, SF3, and SF4 when viewed in cross section. These four faces SF1, SF2, SF3, and SF4 face four directions (indicated by thick arrows), respectively. Here, "four surfaces" means roughly four surfaces. When viewed in cross section, the contours of each surface may be straight or curved. In addition, multiple straight lines and curves may be partially bent. For example, continuous straight lines and curves that are bent within 90 degrees will be treated as roughly one surface in this context.

[0033] 2 and 3 are also the "intended shape of the polar anisotropic magnet" to be manufactured. Here, the "intended shape of the polar anisotropic magnet" is a so-called arc shape, and when viewed in cross section, an example of a divided ring shape is shown, where N is a natural number greater than or equal to 2. If polar anisotropic magnets 1N and 1S are used, for example, as a cylindrical rotor, the first surface SF1 becomes the outer peripheral surface, and the second surface SF2 becomes the inner peripheral surface.

[0034] Here, the surface among the four surfaces where magnetic flux should be generated in a concentrated manner is defined as the "effective surface VSF." In the polar anisotropic magnets 1N and 1S according to embodiment 1, magnetic flux is generated in a concentrated manner outward from near the center of the effective surface VSF (first surface SF1). When this polar anisotropic magnet is used as a rotor in an electric machine such as a motor, the effective surface VSF is the side that faces the stator. When the effective surface VSF is set on the outer peripheral surface side (first surface SF1), the polar anisotropic magnet can be suitably used as an inner rotor. When the effective surface VSF is set on the inner peripheral surface side (second surface SF2), the polar anisotropic magnet can be suitably used as an outer rotor.

[0035] In the polar-anisotropic magnet 1N shown in Figure 3(a), the first surface SF1 is the effective surface VSF. An N pole (one magnetic pole) is arranged on the effective surface VSF (first surface SF1), and an S pole (other magnetic pole) is arranged on the remaining second surface SF2, third surface SF3, and fourth surface SF4 other than the effective surface VSF. On the other hand, the polar-anisotropic magnet 1S shown in Figure 3(b) is magnetized in the opposite direction to the polar-anisotropic magnet 1N, and an S pole (one magnetic pole) is arranged on the effective surface VSF (first surface SF1), and an N pole (other magnetic pole) is arranged on the remaining second surface SF2, third surface SF3, and fourth surface SF4 other than the effective surface VSF. The polar anisotropic magnets 1N and 1S shown in FIG. 3 are also included in the first embodiment.

[0036] (4) Different polar anisotropic magnets 1N and 1S with curved magnetization directions FIG. 4 is a diagram for explaining another example of polar anisotropic magnets 1N and 1S. FIG. 3 shows polar-anisotropic magnets 1N, 1S with a linear magnetization direction. Another polar-anisotropic magnet 1N, 1S shown in FIG. 4, whose internal magnetization direction forms a curve when traced, is also considered as a magnet similar in configuration to the polar-anisotropic magnets 1N, 1S shown in FIG. 3 and capable of extracting magnetic properties substantially equivalent to those of the polar-anisotropic magnets 1N, 1S. Such another polar-anisotropic magnet 1N, 1S is also subject to the first embodiment. Note that the explanation of the four surfaces (SF1, SF2, SF3, SF4), effective surface VSF, etc. of the another polar-anisotropic magnet 1N, 1S shown in FIG. 4 is based on the explanation of the polar-anisotropic magnets 1N, 1S shown in FIG. 3 above. The polar anisotropic magnets 1N, 1S and the magnet assembly 100 will be described in detail later.

[0037] 2. Method for manufacturing polar anisotropic magnet according to embodiment 1 Fig. 5 is a flowchart illustrating the manufacturing method of the polar anisotropic magnet according to embodiment 1. Fig. 6 is a schematic cross-sectional view showing how the in-magnetic-field compacting step S20 is carried out. Fig. 7 is a schematic diagram of the magnetic base material M1 removed after carrying out the in-magnetic-field compacting step S20. Fig. 8 is a schematic diagram of the magnetic base material M2 removed after carrying out the processing step S32. The two-dot chain line in Fig. 8 indicates the outline of what was previously the outer shape of the magnetic base material M1. Fig. 9 is a schematic diagram of the magnetic base material M2' removed after carrying out the surface treatment step S33. Fig. 10 is a schematic cross-sectional view showing how the four-directional magnetizing step S40 is carried out.

[0038] 5, the method for producing a polar-anisotropic magnet according to embodiment 1 includes at least a powder material preparation step S10, a magnetic field compacting step S20, and a four-directional magnetizing step S40, in this order. In embodiment 1, an intermediate step S30 (e.g., a sintering / heat treatment step S31) is further included between the magnetic field compacting step S20 and the four-directional magnetizing step S40.

[0039] (1) Powder material preparation process S10 The powder material preparation step S10 is a step in which powder material PD for magnets is prepared. Powder material for magnets can be prepared by using existing common methods. For example, in the case of a neodymium magnet, raw materials such as neodymium, iron, and boron are melted and solidified, and the solid material is then coarsely and finely crushed using a crusher, mill, etc. to prepare powder material PD for magnets.

[0040] (2) Magnetic field molding process S20 The magnetic field molding process S20 is a process in which a magnetic field in a first direction is applied to a virtual effective surface VSF' (the term virtual is used because the prototype of the polar anisotropic magnet has not yet been formed) from the outside of a mold 710 corresponding to the desired shape of the polar anisotropic magnet, while a magnetic field in a second direction is applied to the remaining three surfaces, and powder material PD is sequentially poured into the inside of the mold 710, thereby molding a magnet base material M1 having a shape that matches the shape of the mold 710 (see Figures 5 and 6).

[0041] As a specific configuration, as shown in Figure 6, a form 710 corresponding to the "desired shape of the polar anisotropic magnet" is prepared, and a first magnetic force source 721 is arranged outside of the form 710 so that its first magnetic pole faces a virtual effective surface VSF', and second magnetic force sources 722b, 722a, and 722c are arranged so that their second magnetic poles face each of the remaining three faces (the bottom, right side, and left side in the figure) other than the virtual effective surface out of the four faces. Figure 6 shows an example in which the first magnetic pole is a north pole and the second magnetic pole is a south pole.

[0042] After this arrangement, a magnetic field in a first direction is applied to the virtual effective surface VSF' by the first magnetic source 721, and a magnetic field in a second direction is applied to the remaining three surfaces by the second magnetic source 722. At this time, powder material PD is sequentially poured into the mold 710, and a magnetic base material M1 having a shape that conforms to the mold 710 is formed. Note that a binder is mixed with the powder material PD before it is poured into the mold 710. When the powder material PD is poured into the mold 710 to which a predetermined magnetic field is applied, the direction of each molecule of the powder material PD aligns with the direction of the magnetic field, and the powder is layered. At this time, pressure is applied from the outside of the mold 710.

[0043] By carrying out the magnetic field forming step S20 in this manner, it is possible to obtain, for example, the magnetic base material M1 shown in Figure 7. The solid lines in the magnetic base material M1 shown in Figure 7 schematically indicate the molecular arrangement direction (molecular orientation).

[0044] The widths of the first magnetic source 721 and the second magnetic source 722, as well as the positions of the first magnetic pole (peak portion) of the first magnetic source 721 and the second magnetic pole (peak portion) of the second magnetic source 722 relative to the mold 710, can be appropriately changed according to the design intent. Furthermore, the output (strength of the applied magnetic field) of the first magnetic source 721 and the second magnetic source 722 on each surface can also be appropriately adjusted according to the design intent. In this case, the molecular alignment direction (molecular orientation / magnetization easy axis / magnet alignment) can be easily changed appropriately by adjusting the strength of the magnetic field lines of the second magnetic sources 722b, 722a, and 722c. Consequently, the magnetic flux density form of the magnetic field lines output from the effective surfaces VSF of the polar anisotropic magnets 1N and 1S can also be appropriately designed and modified.

[0045] Here, the "first direction" and the "second direction" indicate either a direction toward the inside or a direction toward the outside of the formwork 710, and the first direction and the second direction are opposite to each other. In the example of Fig. 6, the "first direction" is the direction in which the magnetic field lines point from the first magnetic pole of the first magnetic source 721 to the inside of the formwork 710, and the "second direction" is the direction in which the magnetic field lines point from the inside of the formwork 710 to the second magnetic pole of the second magnetic source 722. The "first direction" and the "second direction" are not limited to the directions relative to the formwork 710 as described above, but are similarly defined as directions relative to the magnet materials M2 and M2'.

[0046] Furthermore, by arranging the inner circumferential surface SF2 facing the first magnetic force source 721 and the outer circumferential surface SF1 facing the second magnetic force source 722b, it is also possible to create a polar anisotropic magnet having an effective surface VSF on the inner circumferential surface SF2. This type of modification can also be performed in the four-directional magnetization process S40 (FIG. 10 and others) described later.

[0047] (3) Intermediate process S30 The intermediate step S30 is a step in which intermediate processing is carried out on the magnet base material M1 obtained in the magnetic field molding step S20 in order to input it into the four-way magnetization step S40, which will be described later (see FIG. 5).

[0048] In the first embodiment, the magnet base material M1 (see FIG. 7) obtained in the magnetic field molding step S20 is sintered and heat-treated in the sintering and heat treatment step S31. When the sintering and heat treatment step S31 is performed, the binder contained in the magnet base material M1 is vaporized by heat and removed, increasing the purity of the magnetic material. Furthermore, although the magnet base material M1 may be slightly magnetized inside as a result of the magnetic field molding, it is possible to demagnetize it by performing the sintering and heat treatment step S31.

[0049] In the first embodiment, following the sintering and heat treatment step S31, a processing step S32 is carried out in which the sintered and heat treated magnet base material M1 is processed into the "desired shape of the polar anisotropic magnet" to produce magnet material M2 (see FIG. 8). Then, a surface treatment step S33 is carried out in which magnet material M2 is subjected to a surface treatment for rust prevention (e.g., nickel plating, gloss chromate treatment, electro-deposition coating, etc.) to produce magnet material M2' (see FIG. 9; reference numeral 7 denotes a surface treatment layer), and finally, an inspection step S34 is carried out in which the finished state of magnet material M2' is inspected. It should be noted that if the inner shape of the mold 710 is the "intended shape of the polar anisotropic magnet," the machining step S32 may not be performed. Also, the surface treatment step S33 may not be performed.

[0050] (4) Four-way magnetization process S40 The four-way magnetization process S40 is a process of magnetizing the magnetic materials M2, M2' obtained based on the magnetic base material by applying a magnetic field in a first direction to the effective surface VSF (SF1) of the magnetic materials M2, M2' and a magnetic field in a second direction to the remaining three surfaces (SF2, SF3, SF4) of the magnetic materials M2, M2' so as to surround the magnetic materials M2, M2' (see Figures 5 and 10).

[0051] 10, a first magnetizing magnetic source 731 is first arranged so as to surround the magnetic materials M2, M2' obtained from the magnetic mother material M1, with its first magnetic pole facing the effective surface VSF (first surface SF1), and second magnetizing magnetic sources 732b, 732a, and 732c are also arranged so as to face the second magnetic poles on the remaining three surfaces (second surface SF2, third surface SF3, and fourth surface SF4). Note that so-called magnetizing yokes may be used as the first magnetizing magnetic source 731 and the second magnetizing magnetic sources 732b, 732a, and 732c.

[0052] Then, the first magnetic source for magnetization 731 and the second magnetic sources for magnetization 732a, 732b, and 732c are activated to apply a magnetic field in a first direction to the effective surface VSF (first surface SF1) and a magnetic field in a second direction to the remaining three surfaces (second surface SF2, third surface SF3, and fourth surface SF4), thereby magnetizing the magnetic material M2. The electric field can be applied by any suitable existing method. The first magnetic pole, the second magnetic pole, the first direction, and the second direction are explained in the magnetic field molding step S20. By carrying out the four-way magnetization step S40 in this manner, a polar anisotropic magnet 1N or 2N as shown in FIG. 2 or FIG. 3 can be obtained.

[0053] It should be noted that the widths of the first magnetizing magnetic source 731 and the second magnetizing magnetic source 732 and the arrangement positions of the first magnetic pole (peak portion) of the first magnetizing magnetic source 731 and the second magnetic pole (peak portion) of the second magnetizing magnetic source 732 can be changed as appropriate according to the design intent. In addition, the outputs (strength of the magnetic field to be applied) of the first magnetizing magnetic source 731 and the second magnetizing magnetic source 732 on each surface can also be set to appropriate magnitudes (strength of the magnetic field) according to the design intent. By making such adjustments as appropriate, the thickness of the parts with horizontal polar anisotropy arrangement and the thickness of the parts with vertical radial anisotropy arrangement can be set as desired when the polar anisotropic magnets 1N and 1S are finished, and the density of the virtual lines indicating the magnetization direction can also be changed as appropriate.

[0054] In the above explanation and the corresponding drawings, an example of manufacturing a polar anisotropic magnet 1N has been taken up as an example, but when manufacturing a polar anisotropic magnet 1S, the same can be done by swapping the polarities so that the first magnetic pole is the S pole and the second magnetic pole is the N pole, and then reversing the directions of the first and second directions.

[0055] 3. Polar anisotropic magnets 1N and 1S according to embodiment 1 Next, returning to FIG. 4, a supplementary explanation will be given of the configuration of the polar anisotropic magnets 1N and 1S obtained by the above-described method for manufacturing a polar anisotropic magnet.

[0056] Polar-anisotropic magnets 1N and 1S are polar-anisotropic magnets that have four surfaces (first surface SF1, second surface SF2, third surface SF3, and fourth surface SF4) that face four directions (indicated by thick arrows) when viewed in cross section. If the surface on which magnetic flux should be concentrated among the four surfaces SF1, SF2, SF3, and SF4 of polar-anisotropic magnets 1N and 1S is defined as the effective surface VSF (SF1), one magnetic pole is located on the effective surface VSF (SF1), and the other magnetic poles are located on the remaining three surfaces (SF2, SF3, and SF4) other than the effective surface VSF. When one magnetic pole is a north pole, the other magnetic poles become south poles. Conversely, when one magnetic pole is a south pole, the other magnetic poles become north poles.

[0057] The polar-anisotropic magnets 1N, 1S described in the first embodiment have a divided ring shape when viewed in cross section, where N is a natural number equal to or greater than 2, and when the polar-anisotropic magnets 1N, 1S are used, for example, as a cylindrical rotor, the first surface SF1 becomes the outer peripheral surface and the second surface SF2 becomes the inner peripheral surface.

[0058] 2 and 3, for example, the portion from the upper side of the third surface SF3 to the center of the first surface SF1 has a magnetization direction that is relatively close to horizontal, which is a so-called horizontal polar anisotropy arrangement. Also, for example, the portion near the lower side of the third surface SF3 and the portion near the second surface SF2 has a magnetization direction that is relatively close to vertical, which is a so-called vertical radial anisotropy arrangement.

[0059] Furthermore, when the polar anisotropic magnets 1N and 1S are viewed in cross section, there are no adhesive marks inside and the inside is formed continuously, making the polar anisotropic magnets 1N and 1S one continuous solid member.

[0060] 4. Effects of the manufacturing method of the polar anisotropic magnet, the polar anisotropic magnet, and the magnet assembly according to embodiment 1 The manufacturing method of the polar anisotropic magnet according to embodiment 1 involves arranging a magnetic source (first magnetic source 721 or first magnetic source for magnetization 731) so that the first magnetic pole faces the effective surface VSF (including virtual effective surface VSF') (SF1), and arranging a magnetic source (second magnetic source 722 or second magnetic source for magnetization 732) so that the second magnetic pole faces the remaining three surfaces SF2, SF3, and SF4 other than the effective surface VSF (SF1), and then applying a magnetic field in a first direction to the effective surface VSF and a magnetic field in a second direction to the remaining three surfaces. Therefore, the manufacturing method for the polar anisotropic magnet according to embodiment 1 can collectively manufacture polar anisotropic magnets 1N and 1S that have both portions with horizontal polar anisotropic arrangement and portions with vertical radial anisotropic arrangement, thereby enabling a significant improvement in mass productivity compared to conventional manufacturing methods for Halbach array magnet assemblies and similar magnet assemblies.

[0061] Furthermore, by appropriately changing the positions of the magnetic sources (first magnetic source 721, second magnetic source 722, first magnetizing magnetic source 731, second magnetizing magnetic source 732) for each of the four surfaces SF1, SF2, and SF4, or by appropriately changing the output of each magnetic source (strength of the applied magnetic field), it is possible to appropriately change both the thickness of the portion with horizontal polar anisotropy and the thickness of the portion with vertical radial anisotropy. In other words, there is no design constraint similar to the trade-off between the radial thickness of the outer cylindrical body 900EX and the thickness of the inner cylindrical body 900IN, as in the manufacturing method of magnet assembly 900 described in Patent Document 1.

[0062] As described above, the method for manufacturing a polar anisotropic magnet according to embodiment 1 can improve mass productivity and also increase the degree of freedom in designing the thickness of the horizontal polar anisotropic arrangement and the thickness of the vertical radial anisotropic arrangement. In other words, this is a method for manufacturing a polar anisotropic magnet that offers greater design freedom and is more economical than conventional methods.

[0063] Furthermore, to obtain the magnet assembly 100 of embodiment 1, polar-anisotropic magnets 1N and 1S with different magnetization directions are joined together. In this case, for example, the south pole appearing on the first surface SF1 of polar-anisotropic magnet 1N and the north pole appearing on the fourth surface SF4 of polar-anisotropic magnet 1S will attract each other, making it extremely easy to arrange, join, and adhere multiple polar-anisotropic magnets. Therefore, this also contributes to improving mass productivity.

[0064] 5. Magnet assembly 100 according to embodiment 1 11A and 11B are diagrams shown to explain the magnet assembly 100 according to embodiment 1. Fig. 11A is a cross-sectional view of the magnet assembly 100, and Fig. 11B is a perspective view of the magnet assembly 100.

[0065] 11, in the magnet assembly 100, polar anisotropic magnets are arranged and joined together so that one magnetic pole and the other magnetic pole appear alternately on the outside. Specifically, in the magnet assembly 100, polar anisotropic magnets 1N and polar anisotropic magnets 1S are arranged alternately in a predetermined direction, and two adjacent polar anisotropic magnets are magnetized in opposite directions.

[0066] In other words, the magnet assembly 100 here is formed by arranging polar anisotropic magnets 1N, 1S in a circumferential direction around the axis AX, and has a substantially cylindrical outer shape. Here, polar anisotropic magnet 1N and polar anisotropic magnet 1S, which have the shape of split rings obtained by dividing a circular ring into eight equal parts (N=8), are joined and adhered to each other so that their third surfaces SF3 and fourth surfaces SF4 are in contact with each other, and their first surfaces SF1 (effective surfaces VSF) form the same surface (formed so that there is no gap at the joint).

[0067] [Application example] FIG. 12 is a diagram shown for explaining a motor 510, a generator 520, and an actuator 530 as application examples using the polar anisotropic magnet and magnet assembly according to each embodiment. The polar anisotropic magnets 1N, 1S obtained in embodiment 1 and the magnet assembly 100 constructed using them can be applied to a variety of product fields. For example, they can be used to construct a motor (see FIG. 12(a)) with a rotor including the magnet assembly 100, a generator (see FIG. 12(b)) with a rotor including the magnet assembly 100, an actuator (see FIG. 12(c)) with a rotor including the magnet assembly 100, etc.

[0068] Although the present invention has been described above based on the above-mentioned embodiment 1, the present invention is not limited to the above-mentioned embodiment 1. The present invention can be embodied in various aspects without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0069] (1) In the magnetic field molding process S20 and / or the four-directional magnetization process S40 of embodiment 1, the width of the side on which the first magnetic pole of the first magnetic force source 721 or the first magnetic force source for magnetization 731 is arranged is approximately equal to the width of the effective surface VSF (including the virtual effective surface), but the present invention is not limited to this. 13 is a diagram for explaining a modified example of the method for performing the four-direction magnetizing step S40. For example, as shown in FIG. 13, in the four-direction magnetizing step S40, the width W1 of the side where the first magnetic pole of the first magnetic force source for magnetization 731 is arranged may be set to be smaller than the width W2 of the effective surface VSF. In other words, the magnetic field application surface of the first magnetic force source for magnetization 731 facing the effective surface VSF may be set to overlap only a part of the effective surface VSF. By doing so, it is possible to adjust the density of the distribution of magnetic flux density generated outside the effective surface VSF and the strength of the magnetic lines of force.

[0070] 13 and the above description, a modified method for performing the four-directional magnetization step S40 has been mentioned, but the same method may be performed in the in-magnetic-field molding step S20. That is, in the in-magnetic-field molding step S20, the width of the side where the first magnetic pole of the first magnetic force source 721 is arranged may be set smaller than the width of the virtual effective surface VSF'.

[0071] (2) In the manufacturing method for a polar-anisotropic magnet according to the first embodiment, split ring-shaped polar-anisotropic magnets that are part of a cylindrical magnet assembly 100 are described, and when the magnet assembly 100 is assembled, the split ring-shaped polar-anisotropic magnets are capable of generating high-density magnetic flux outside the outer circumference of the cylinder. However, the present invention is not limited to this. For example, in the magnetic field molding step S20 and the four-direction magnetizing step S40, the second surface SF2 is set as the effective surface VSF, and the remaining three surfaces other than the effective surface VSF are set as the first surface SF1, the third surface SF3, and the fourth surface SF4. By changing the polarity of each magnetic force source and magnetizing magnetic force source and the settings of the magnetic field to be applied so that the lines of the molecular alignment direction or the lines of the magnetization direction converge on the inner circumference side of the arc-shaped polar-anisotropic magnet, it is possible to manufacture a polar-anisotropic magnet that can generate high-density magnetic flux inside the inner circumference of the cylinder. Such a polar-anisotropic magnet can be suitably used, for example, as an outer rotor.

[0072] (3) Although the magnet assembly 100 according to the first embodiment has been described as being substantially cylindrical, the present invention is not limited to this. For example, as shown in Fig. 14(a), it is also possible to use a linear-type magnet assembly 110 or an arc-type magnet assembly 120. Note that Fig. 14 is a diagram shown to explain magnet assemblies 110 and 120 according to modified examples.

[0073] (4) The manufacturing method for a polar-anisotropic magnet, polar-anisotropic magnets 1N and 1S, and magnet assembly 100 according to embodiment 1 have been described as corresponding to magnet assembly 900 shown in Figure 3 of Patent Document 1, but the present invention is not limited to this. For example, the manufacturing method for a polar-anisotropic magnet according to embodiment 1 can also be applied to polar-anisotropic magnets used in magnet assemblies with a Halbach array, or magnet assemblies based on a Halbach array.

[0074] (5) The polar anisotropic magnet manufacturing method and polar anisotropic magnets 1N and 1S according to the present invention can also be applied to magnet units with a double structure using opposing magnetic fields. 15 is a diagram showing a cylindrical double-structure magnet unit 400. The cylindrical double-structure magnet unit 400 comprises an outer circumferential magnet assembly 400EX and an inner circumferential magnet assembly 400IN. The polar-anisotropic magnets 1N, 1N', 1S, and 1S' that make up the magnet assemblies 400EX and 400IN can also be obtained by the polar-anisotropic magnet manufacturing method of the present invention, and the polar-anisotropic magnets 1N, 1N', 1S, and 1S' of the present invention can be applied to the magnet assemblies 400EX and 400IN.

[0075] 16 is a diagram showing a linear double-structure magnet unit 420. The linear double-structure magnet unit 420 comprises an upper (for convenience of explanation, the terms "upper" and "lower" are used) magnet assembly 420U, a lower magnet assembly 420L, and a magnet assembly 430 disposed between them. The polar-anisotropic magnets 2N, 2N', 2S, and 2S' that make up the magnet assemblies 420U and 420L can also be obtained by the polar-anisotropic magnet manufacturing method of the present invention, and the polar-anisotropic magnets 2N, 2N', 2S, and 2S' of the present invention can be applied to the magnet assemblies 420U and 420L.

[0076] (6) In the first embodiment and the modified examples, a polar-anisotropic magnet having four sides (four faces) in cross section has been described, but this is not limited to this. The first embodiment is not limited to four faces and can also be applied to polar-anisotropic magnets having three or five or more faces. For example, in a magnetic base material M1 and a magnetic material M2 having three triangular faces in cross section, or in a magnetic base material M1 and a magnetic material M2 having six hexagonal faces in cross section, it is possible to apply a magnetic field in a first direction to one face and a magnetic field in a second direction to the remaining faces. This makes it possible to obtain a polar-anisotropic magnet having one magnetic pole (e.g., a north pole) on one face and another magnetic pole (e.g., a south pole) on the other face.

[0077] B. Manufacturing method of magnet assembly using parallel magnetic field and cutting technology Next, a method for manufacturing a magnet assembly using parallel magnetic field and cutting techniques will be disclosed.

[0078] [Embodiment 2] 1. Manufacturing method of magnet assembly according to embodiment 2 17 is a flowchart shown to explain a method for manufacturing a magnet assembly according to embodiment 2. As embodiment 2, a method for manufacturing the outer periphery side magnet assembly 100EX will be explained below.

[0079] The method for manufacturing a magnet assembly according to the second embodiment is a method for manufacturing a cylindrical magnet assembly. As shown in Fig. 17, the method for manufacturing a magnet assembly according to the second embodiment includes at least a powder material preparation step SS10, a magnetic field compaction step SS20, a cutting step SS40, an assembling step SS60, and a magnetization step SS70, in this order. In the second embodiment, a sintering / heat treatment step SS30 is further included between the magnetic field compaction step SS20 and the cutting step SS40. Furthermore, a surface treatment step SS50 is further included between the cutting step SS40 and the assembling step SS60. For reference, the right side of Fig. 17 shows the materials and components input and output to and from each of the specified steps.

[0080] (1) Powder material preparation process SS10 The powder material preparation process SS10 is a process for preparing powder material PD for magnets. Powder material for magnets can be prepared using existing common methods. For example, in the case of neodymium magnets, raw materials such as neodymium, iron, and boron are melted and solidified, and the solid material is then coarsely and finely crushed using a crusher or mill to prepare powder material PD for magnets.

[0081] (2) Magnetic field molding process SS20 Figure 18 is a diagram used to explain the in-magnetic field forming step SS20. Figure 18(a) is a perspective view showing the in-magnetic field forming, Figure 18(b) is a perspective view of magnetic base material 10, Figure 18(c) is a cross-sectional view of magnetic base material 10 in Figure 18(b) taken along imaginary plane PL1, and Figure 18(d) is a cross-sectional view of magnetic base material 10 in Figure 18(b) taken along imaginary plane PL2.

[0082] The magnetic field molding process SS20 is a process for molding a "magnet base material 10" having a first main surface 11 and a second main surface 12 opposite to the first main surface 11 (see Figure 18(b)). In the figure, reference numeral 13a denotes side A, 13b denotes side B, 13c denotes side C, and 13d denotes side D. In the magnetic field molding process SS20, the powder material PD prepared in the powder material preparation process SS10 is poured into the inside of a mold 890 corresponding to the shape of the magnet base material 10 (not shown), and a parallel magnetic field is applied in a single direction from the side corresponding to the first main surface 11 (upper side in the figure) on the outside of the mold 890 to the side corresponding to the second main surface 12 (lower side in the figure).

[0083] As a specific configuration, for example, a first magnetic source (not shown) is arranged outside mold 890 on the side that will become first main surface 11 when molded into magnet base material 10 (the upper side of mold 890 in the figure) so that its north pole faces, and a second magnetic source (not shown) is arranged on the side that will become second main surface 12 (the lower side of mold 890 in the figure) so that its south pole faces. Then, by operating the first magnetic source and the second magnetic source, a magnetic field is applied uniformly across first main surface 11 and second main surface 12, perpendicular to first main surface 11 and second main surface 12, so that the magnetic field lines are parallel to each other, and so that the magnetic flux density is the same (see FIG. 18(a)). Note that while a magnetic field directed from the top to the bottom of the figure is illustrated here, the magnetic field direction may be reversed.

[0084] When the above-described magnetic field is applied while pressure is applied inside the mold 890, the molecules of the powder material PD are aligned in the direction of the magnetic field and orient along the direction of the magnetic field, and a magnet base material 10 having an overall shape corresponding to the shape of the mold 890 is formed (see Figure 18(b)). The first main surface 11 is substantially flat. The second main surface 12 is also substantially flat and substantially parallel to the first main surface. However, this is not limited to this. Inside the magnet base material 10, the molecular direction is uniformly oriented in a direction perpendicular to the first main surface 11 and the second main surface 12, as shown by the dashed lines in Figures 18(c) and 18(d). Once the molecular direction is aligned, by performing the magnetization process SS70 described below, the molecules will be strongly magnetized along this alignment direction. The orientation of each powder in the powder material PD (the molecular orientation direction) aligned by performing the magnetic field compaction process SS20 in this way is sometimes referred to in this specification as the "axis of easy magnetization."

[0085] (3) Sintering and heat treatment process SS30 The sintering and heat treatment process SS30 sinters and heat treats the magnet base material 10 obtained in the magnetic field molding process SS20. When the sintering and heat treatment process SS30 is carried out, the binder contained in the magnet base material 10 is vaporized by heat and removed, increasing the purity of the magnetic material. Also, although the magnet base material M1 may be slightly magnetized inside as a result of magnetic field molding, it is possible to demagnetize it by carrying out sintering and heat treatment.

[0086] (4) Cutting process SS40 (4-1) Cutting out the magnet base material piece 20 Figure 19 is a diagram used to explain cutting step SS40. Figure 19(a) is a right side view of the magnet base material 10 before cutting, as viewed from a direction perpendicular to the C-side surface 13c. The solid lines (imaginary lines) drawn on the cross section of the magnet base material 10 are cutting lines along which the cutting is carried out, and are, in a sense, scribe lines. When cutting along the cutting lines, the outline (outer surface) of the magnet base material piece 20, which will be described later, will be exposed to the outside. Figure 19(b) is a perspective view showing the magnet base material piece 20 obtained after carrying out cutting step SS40.

[0087] The cutting step SS40 is a step of cutting out magnet base material pieces 20, which will be described later, by cutting the magnet base material 10 along the cutting lines described above. The cutting step SS40 here is performed by wire cutting. When performing wire cutting, it is preferable to perform cutting while cooling. The processing method used in the cutting step SS40 is not limited to wire cutting, and may be, for example, water jet cutting or machining. This method allows specification changes to be made using only conventional general magnet manufacturing equipment, without having to develop a new mold each time specifications are changed, as is the case with conventional magnet assembly manufacturing methods.

[0088] (4-2) Setting the cutting line Here, the surface that will become the outer diameter surface of the magnet assembly when assembled is defined as the "planned outer diameter surface 20EX," and the surface that will become the inner diameter surface is defined as the "planned inner diameter surface 20IN." Note that the cut lines corresponding to these before cutting are denoted by the same reference numerals with an "'" added. In the second embodiment, cutting is performed so that the planned outer diameter surface 20EX and / or the planned inner diameter surface 20IN cut out in the cutting process are flat. By making the planned outer diameter surface 20EX and / or the planned inner diameter surface 20IN flat, the cutting work becomes simpler than when they are curved surfaces, and it is expected that productivity will be improved while maintaining high precision. In the second embodiment, the planned outer diameter surface 20EX and the planned inner diameter surface 20IN are parallel to each other.

[0089] 19(a), the cut line 20EX' of the planned outer diameter surface is set to have an inclination angle θ1 with respect to the first main surface 11. Also, the cut line 20IN' of the planned inner diameter surface is set to have an inclination angle θ2 with respect to the first main surface 11. In the second embodiment, the planned outer diameter surface and the planned inner diameter surface are parallel to each other, so here the relationship θ1 = θ2 holds. Here, the cutting lines are set based on the first main surface 11, but in practice, the cutting lines may be set based on either the first main surface 11 or the second main surface 12. Therefore, in this specification, the "first main surface 11" may be replaced with the "second main surface 12," and such a case is also considered to be within the technical scope of the present invention.

[0090] (4-3) Cutting line parameters In the cutting process SS40 of embodiment 2, the angles θ1 and θ2 relative to the first main surface 11 are each set within a range greater than 45 degrees and less than 90 degrees, and under these settings, the magnet base material 10 is cut along the cut line 20EX' of the planned outer diameter surface and the cut line 20IN' of the planned inner diameter surface. In other words, in the cutting process SS40 of embodiment 2, the cut line 20EX' of the intended outer diameter surface is set in a range of more than 0 degrees and less than 45 degrees with respect to the axis of easy magnetization (the direction of the dashed line) (θ3), and the cut line 20IN' of the intended inner diameter surface is set in a range of more than 0 degrees and less than 45 degrees with respect to the axis of easy magnetization (θ4). Under these settings, the magnet base material 10 is cut along the cut line 20EX' of the intended outer diameter surface and the cut line 20IN' of the intended inner diameter surface (see Figure 19(a)). By setting θ1, θ2, θ3, and θ4 in this manner, it is possible to manufacture a magnet assembly (magnet assembly on the outer periphery) with horizontal polar anisotropic arrangement.

[0091] (4-4) Cutting out the magnet base material piece 20 Next, after the cutting lines are determined as described above, the magnet base material 10 is cut along the cutting line 20EX' of the planned outer diameter surface, and also cut along the cutting line 20IN' of the planned inner diameter surface, to cut out a magnet base material piece 20 having at least the planned outer diameter surface 20EX and the planned inner diameter surface 20IN on its outer surfaces (see Figure 19(b)).

[0092] As shown in Figure 19(b), the magnet base material piece 20 cut out in the cutting step SS40 has on its outer surface a planned outer diameter surface 20EX and a planned inner diameter surface 20IN, as well as joining side surfaces 21, 24 that will be joined together during the subsequent assembling step SS60. In the example of embodiment 2, the joining side surface 21 is a portion that was the same surface as the first main surface 11 of the magnet base material 10 before the cutting step SS40. The joining side surface 24 is a newly emerged surface that has been cut along a separate cutting line. The magnet base material piece 20 also has a surface 22 on one end side in the longitudinal direction and a surface 23 on the other end side. Note that in Figure 19, a plurality of magnet base material pieces 20 -1 ,20 -2 ,20 -3 ,20 -4 Although an example in which , , are cut out is shown, the case in which a single number is cut out is also included in the embodiment of the cutting step SS40 here.

[0093] (5) Surface treatment process SS50 The surface treatment step is a step in which the magnet base material piece 20 is subjected to a surface treatment (for example, nickel plating, gloss chromate treatment, electrodeposition coating, electrostatic coating, etc.) for rust prevention.

[0094] (6) Assembly process SS60 Figure 20 is a diagram for explaining the assembly process SS60. Figure 20(a) is a diagram showing four magnet base material pieces 20 assembled together. Figure 20(b) is a perspective view showing a magnet base material assembly 40EX. For reference, the area indicated by the dashed line SA in Figure 20(b) is as shown in Figure 20(a).

[0095] The assembling process SS60 is a process of assembling a magnet base material assembly 40EX by combining multiple magnet base material pieces 20. Specifically, multiple magnet base material pieces 20 obtained in the cutting process SS40 are prepared (see Figure 19(b)), and the joining side surfaces 21, 24 of the magnet base material pieces 20 are joined and bonded to each other. At this time, adjacent planned outer diameter surfaces 20EX and adjacent planned inner diameter surfaces 20IN are joined without any gaps (corners may be formed) at the joints. In this way, continuous outer and inner peripheral surfaces can be formed by combining multiple magnet base material pieces 20.

[0096] As an example, a case where four magnet base material pieces 20 of FIG. 19(b) are combined will be described (see FIG. 20(a)). From the left side, first, the magnet base material piece 20 is placed with the surface 22 on one end side facing forward. -1 Place the To the right of it, one end and the other end are swapped in the longitudinal direction so that the other end 23 is in front. -2 At this time, the magnet base material piece 20 -1 The joining side 24 and the magnet base material piece 20 -2 Next, the magnet base material piece 20 is joined to the right of the first end surface 22 with the first end surface 22 facing forward. -3 At this time, the magnet base material piece 20 -2 The joining side 21 and the magnet base material piece 20 -3 Next, to the right of the magnet base material piece 20, the longitudinal ends are swapped so that the other end 23 is in front. -4 At this time, the magnet base material piece 20 -3 The joining side 24 and the magnet base material piece 20 -4 The joining side surface 24 of the first and second plates 21 and 22 are joined together. In this way, four magnet base pieces 20 -1 ~20 -4 By repeating this assembly process, a magnet base material assembly 40EX shown in Fig. 20(b) can be obtained.

[0097] (7) Magnetization process SS70 Fig. 21 is a diagram for explaining the magnetization step SS70. Fig. 21(a) is a cross-sectional view showing the arrangement of magnetic sources 840N, 840S when magnetizing, and Fig. 21(b) is a cross-sectional view of the magnet assembly 100EX after the magnetization step has been performed.

[0098] The magnetization step SS70 is a step of applying a predetermined magnetic field to the magnet base material assembly 40EX from outside at a predetermined position to magnetize the magnet base material assembly 40EX. For example, as shown in Fig. 21(a), four magnetic sources 840N, 840S made up of magnetizing yokes are arranged at equal angles with alternating polarities along the outer diameter surface of the magnet base material assembly 40EX (more precisely, the circumference around the central axis). The poles of the magnetic sources 840N, 840S are arranged at positions of the joint (positions P1, P2 in Fig. 23(a)) that approach the joint side surfaces 21, 24 as they move radially outward from the central axis. Then, the magnetic sources 840N and 840S are activated at a predetermined timing with a predetermined output to apply a magnetic field to the magnet base material assembly 40EX. In this way, the interior of the magnet base material assembly 40EX can be magnetized in the molecular orientation direction (axis of easy magnetization) formed in the magnetic field molding step SS20. As a result, the magnet assembly 100EX is magnetized in the direction (magnetization direction) shown in Figure 21(b).

[0099] By carrying out at least the above-described magnetic field molding step SS20, cutting step SS40, assembling step SS60, and magnetizing step SS70, the magnet assembly 100EX can be obtained.

[0100] 2. Magnet Assembly 100EX Next, a magnet assembly 100EX obtained by the manufacturing method of a magnet assembly according to the second embodiment will be described. As shown in Figure 21(b), the magnet assembly 100EX has approximately flat outer and inner diameter surfaces, and is equipped with magnet blocks 50 that are magnetized parallel to a single direction at a predetermined angle (θ3, θ4) relative to the outer and inner diameter surfaces, and multiple (here, N) magnet blocks 50 are joined to each other via surfaces other than the outer and inner diameter surfaces (joining sides 21, 24 in Figure 20(a)). Specifically, the magnet assembly 100EX is formed by joining N magnet blocks 50 together, and is configured as a cylindrical body having an N-sided polygon on the outer and inner diameter sides made up of the magnet assemblies 100EX. The magnet assembly 100EX shown in Fig. 21(b) is an example in which, when nps (number of same poles) = 2, npNS (number of different poles) = 2, and ns (number of sets, a natural number greater than or equal to 1), ns = 4, and N = 2 2 4 = 16.

[0101] Between the assembly process SS60 and the magnetization process SS70, a cylindrical forming process (not shown) may be carried out to form the entire magnet base material assembly 40EX into a cylindrical shape by removing the corners of the outer diameter surface of the magnet base material assembly 40EX, which has a substantially N-sided cylindrical shape, or by applying a protective film or the like to the outer surface. In this case, the magnet assembly 100EX also becomes cylindrical in shape. In the above, the magnet assembly 100EX is described as being cylindrical and having an approximately N-sided polygonal shape with an approximately flat outer diameter surface. However, a magnet assembly that has undergone the cylindrical forming process and has a curved outer diameter surface or an approximately cylindrical shape as a whole is also included in one aspect of this embodiment, since it was originally approximately flat and has an approximately N-sided polygonal shape.

[0102] 3. Effects of the manufacturing method of the magnet assembly according to the second embodiment The manufacturing method of the magnet assembly of embodiment 2 involves applying a parallel magnetic field in a single direction from the side corresponding to the first main surface 11 to the side corresponding to the second main surface 12 to form the magnet base material 10, then setting the cutting line 20EX' of the planned outer diameter surface to be inclined at an angle θ1 with respect to the first main surface 11 to cut the magnet base material 10, and setting the cutting line 20IN' of the planned inner diameter surface to be inclined at an angle θ2 with respect to the first main surface 11 to cut the magnet base material 10 to cut out magnet base material pieces 20, and then combining the magnet base material pieces 20 to assemble a magnet base material assembly 40EX and magnetizing it to obtain the magnet assembly 100EX.

[0103] In other words, once a magnet base material 10 with a single molecular orientation direction (axis of easy magnetization) is obtained, it is possible to change the design and model of the magnet assembly by changing the cutting angle, shape, etc. in the cutting step SS40. In other words, the magnetization direction, thickness, shape, etc. can be changed as needed simply by appropriately changing the way the cutting lines are set. This allows the method of manufacturing a magnet assembly of the present invention to offer a high degree of design freedom. From another perspective, the processes up to the powder material preparation process SS10, the magnetic field molding process SS20, and the sintering and heat treatment process SS30 are common and standardized, and by simply changing the way the cutting lines are set in the cutting process SS40 as appropriate, it is possible to produce the outer periphery magnet assembly 100EX and the inner periphery magnet assembly 100IN. Therefore, there is no need for large-scale process changes for each product variation. Furthermore, unlike conventional methods, it is not necessary to prepare a dedicated mold for each product variation, and the cutting process SS40 itself can be performed using conventional general magnet manufacturing equipment. In particular, the manufacturing method of embodiment 2 is useful when utilizing equipment that produces sintered magnets using so-called single-pole manufacturing, and since design changes are easy and flexible, it is also useful in the development and prototyping stages, leading to reduced development costs and shorter development periods. In this way, the method for manufacturing a magnet assembly of the present invention is more economical than conventional methods.

[0104] Furthermore, even if the radial thickness of the magnet assembly 100EX to be assembled is thin, the cut angle, cut shape, etc. can be changed as appropriate, and the magnetization direction can be freely controlled even though the magnet assembly is thin. For example, a magnet assembly with a thickness T2 of approximately 1 mm to 2 mm, which was difficult to achieve with conventional manufacturing methods, can be achieved with the manufacturing method of the embodiment (see FIG. 32). Therefore, in this respect as well, the degree of design freedom is higher than with conventional methods. Furthermore, unlike conventional methods, sintering and heat treatment are not performed on thin components, so there is no risk of breakage during the sintering and heat treatment process. This results in a higher yield than conventional methods, making it extremely economical.

[0105] Furthermore, since the parts handled in the assembly process SS60 are non-magnetized magnet base material pieces 20, they are assembled together without any attractive or repulsive forces. This eliminates the problem of attractive or repulsive forces between adjacent magnets that has been an issue when assembling magnets in a Halbach array in the past, making the process very easy to manufacture and suitable for mass production.

[0106] Therefore, the method for manufacturing a magnet assembly according to the second embodiment can provide a method for manufacturing a magnet assembly that offers greater design freedom and is more economical than conventional methods.

[0107] Furthermore, as shown in Figure 32, it is believed that the molecular orientation direction (axis of easy magnetization) is conventionally affected by variations in the arrangement of the magnetic source, the magnitude and output method of the magnetic source, etc. These variations are likely to result in individual differences in the magnetization direction between products, leading to variations in quality. However, the method for manufacturing a magnet assembly according to embodiment 2 simply applies a parallel magnetic field in a single direction, resulting in a uniform molecular orientation direction (axis of easy magnetization) inside the assembly, which reduces variations and makes it easier to maintain high quality.

[0108] [Embodiment 3] FIG. 22 is a cross-sectional view showing the cutting step SS40 of embodiment 3. FIG. 22(a) is a right side view of the magnet base material 10 before cutting, as seen from a direction perpendicular to the C-side surface 13c. FIG. 19(b) is a cross-sectional view showing the magnet base material piece 30 obtained after performing the cutting step SS40. FIG. 23 is a cross-sectional view shown to explain the assembling step SS60 of embodiment 3. FIG. 23(a) is a view showing four magnet base material pieces 30 assembled together. FIG. 23(b) is a perspective view showing a magnet base material assembly 40IN. FIG. 24 is a cross-sectional view of the magnet assembly 100IN after performing the magnetizing step SS70 of embodiment 3. In the figure, reference numeral 30EX denotes the planned outer diameter surface, and 30IN denotes the planned inner diameter surface. Note that for components that have the same basic configuration and features as those in the second embodiment, the same reference numerals as those in the second embodiment are used and the description thereof will be omitted here.

[0109] The manufacturing method for the magnet assembly 100IN according to embodiment 3 is basically similar in configuration to the manufacturing method for the magnet assembly 100EX according to embodiment 2, but differs from the manufacturing method for the magnet assembly 100EX according to embodiment 2 in the settings of the angle, shape, etc. of the cut in the cutting process SS40.

[0110] That is, as shown in Figure 22(a), in the cutting process SS40, the angle θ1 of the cut line 30EX' of the planned outer diameter surface relative to the first main surface 11, and the angle θ2 of the cut line 30IN' of the planned inner diameter surface relative to the first main surface 11 are each set within the range of 0 degrees or more and less than 45 degrees, and under these settings, the magnet base material 10 is cut along the cut line 30EX' of the planned outer diameter surface and the cut line 30IN' of the planned inner diameter surface. In other words, the cut line 30EX' of the planned outer diameter surface and the cut line 30IN' of the planned inner diameter surface are each set in the range of more than 45 degrees and less than 90 degrees with respect to the axis of easy magnetization (the direction of the dashed line), and under such settings, the magnet base material 10 is cut along the cut line 30EX' of the planned outer diameter surface and the cut line 30IN' of the planned inner diameter surface.

[0111] The magnet base material piece 30 obtained after the cutting step SS40 is as shown in Fig. 22(b). Thereafter, by performing the assembling step SS60 in the same manner as in embodiment 2, a magnet base material assembly 40IN can be obtained as shown in Fig. 23(b). Note that Fig. 23(a) corresponds to Fig. 20(a), and Fig. 23(b) corresponds to Fig. 20(b). Thereafter, by performing the magnetizing step SS70, a magnet assembly 100IN as shown in Fig. 24 can be obtained.

[0112] In the manufacturing method for the magnet assembly 100IN according to embodiment 3, the angle of the cut lines is set as described above, so it is possible to manufacture a magnet assembly (the magnet assembly 100IN on the inner circumference side) with a perpendicular polar anisotropic arrangement in which the magnetization direction is closer to a direction perpendicular to the outer diameter surface. Note that, according to the manufacturing method for the magnet assembly 100IN according to embodiment 3, it is also possible to configure the magnetization direction to be at an angle of 90 degrees to the outer diameter surface (so that the magnetization direction coincides with the radial direction).

[0113] The manufacturing method for the magnet assembly 100IN according to embodiment 3 has basically the same configuration as the manufacturing method for the magnet assembly 100EX according to embodiment 2, except for the settings of the angle, shape, etc. of the cut in the cutting step SS40. Therefore, it similarly has the corresponding effects of the manufacturing method for the magnet assembly 100EX according to embodiment 2.

[0114] [Embodiment 4] By combining the magnet assembly 100EX obtained by embodiment 2 with the magnet assembly 100IN obtained by embodiment 3, a composite magnet assembly 100 similar to the magnet assembly 900 described in Patent Document 1 can be obtained (see Figure 30).

[0115] As shown in FIG. 30, the composite magnet assembly 100 is formed by joining together N magnet blocks 50, 60 (see FIGS. 21(b) and 24) and is configured as a cylindrical body with an N-sided polygon on the outer and inner sides made up of the magnet assembly. Here, nps=2: nps is the number of same poles, npNS=2: npNS is the number of different poles, and ns is the number of sets (a natural number greater than or equal to 1), then N is a natural number that satisfies the relationship N=nps·npNS·ns.

[0116] (1) The composite magnet assembly 100 comprises a first type of magnet assembly 100EX obtained by embodiment 2 in which the angle of the magnetization direction relative to the outer diameter surface and inner diameter surface of each magnet block 50 is a first angle (an angle close to 0 degrees), and a second type of magnet assembly 100IN obtained by embodiment 3 in which the angle of the magnetization direction relative to the outer diameter surface and inner diameter surface of each magnet block 60 is a second angle (an angle close to 90 degrees) that is different from the first angle. The composite magnet assembly 100 is joined together with the first embodiment magnet assembly 100EX arranged on the side that should be the effective H magnetic flux surface 100H of the composite magnet assembly 100, and the second embodiment magnet assembly 100IN arranged on the side that should be the effective V magnetic flux surface 100V of the composite magnet assembly (see Figure 30). Here, the "effective H magnetic flux surface" refers to the outer surface of the composite magnet assembly 100, where the magnetization direction in the interior directly below that surface is close to the horizontal (H) direction relative to the outer surface. Also, the "effective V magnetic flux surface" refers to the outer surface of the composite magnet assembly 100, where the magnetization direction in the interior directly below that surface is close to the vertical (V) direction relative to the outer surface. 30 shows a cylindrical composite magnet assembly 100 in which the outer peripheral surface is set as an effective H magnetic flux surface 100H and the inner peripheral surface is set as an effective V magnetic flux surface 100V. This composite magnet assembly 100 can be suitably used as an inner rotor.

[0117] Here, "first angle (θ 10 )" is the angle θ between the tangent at the position of the magnetic pole appearing on the outer peripheral surface (outer diameter surface) of the magnet assembly 100EX and the magnetization direction of the magnet block adjacent to the position immediately below the position of the magnetic pole. 10 In FIG. 21(b), for example, the magnet block 50 -4 and magnet block 50 -5The magnetic pole N appears on the outer peripheral surface of the joint. 10 corresponds to the first angle. Similarly, the second angle (θ 20 ) is the angle θ between the tangent at the position of the magnetic pole appearing on the outer peripheral surface (outer diameter surface) of the magnet assembly 100IN and the magnetization direction of the magnet block adjacent to the position immediately below the position of the magnetic pole. 20 In FIG. 24, for example, a magnet block 60 -5 and magnet block 60 -6 The magnetic pole N appears on the outer peripheral surface of the joint. 20 corresponds to the second angle. Although the above description is based on the outer circumferential surface (outer diameter surface), the same definition applies when based on the inner circumferential surface (outer diameter surface).

[0118] (2) Although the composite magnet assembly 100 described above is a magnet assembly in which the outer peripheral surface is set as the effective H magnetic flux surface 100H, the fourth embodiment is not limited to this. For example, 10 The second angle θ is set to an angle close to 90 degrees. 20 By setting the angle close to 0 degrees, the inner peripheral surface can be set as the effective H magnetic flux surface, thereby configuring a composite magnet assembly of another type (not shown). Such a composite magnet assembly can be suitably used as an outer rotor.

[0119] [Embodiment 5] Fig. 25 is a flowchart shown to explain the method for manufacturing a magnet assembly and a method for manufacturing a polar-anisotropic magnet according to embodiment 5. Fig. 26 is a diagram shown to explain the sub-assembly process SS80. Fig. 27 is a diagram shown to explain the four-directional magnetization process SS85. The members indicated by the reference numerals 45 and 3 in Fig. 27 indicate members in a magnetized state. For components that have the same basic configurations and features as those of embodiments 1 to 4, the reference numerals in embodiments 1 to 4 are used, and the explanations therefor are incorporated, and the explanations for embodiment 5 will be omitted.

[0120] The manufacturing method of the magnet assembly according to embodiment 5 differs from the manufacturing method of the magnet assembly according to embodiment 3 in the scope and manner of the assembly and magnetization processes that follow the cutting process.

[0121] 25 , the manufacturing method for the magnet assembly according to the fifth embodiment includes at least a powder material preparing process SS10, a magnetic field compacting process SS20, a cutting process SS40, a sub-assembly process SS80, and a four-way magnetizing process SS85, in this order. In the fifth embodiment, a magnet assembling process SS90 is further included after the four-way magnetizing process SS85. Note that a surface treatment process SS50 may be performed between the cutting process SS40 and the sub-assembly process SS80, or between the sub-assembly process SS80 and the four-way magnetizing process SS85.

[0122] The powder material preparation step SS10, the magnetic field molding step SS20, and the cutting step SS40 are the same as those steps in the third embodiment.

[0123] The sub-assembly process SS80 is a process for assembling a magnet base material sub-assembly 45 having four surfaces by combining at least four magnet base material pieces 20, 30. Note that the assembly process SS60 described in the third embodiment is composed of this sub-assembly process SS80 in the fifth embodiment. As shown in Figure 26, in the sub-assembly process SS80, a horizontal magnet base material piece 20 cut in the cutting process SS40 with angles θ1 and θ2 each set within the range of more than 45 degrees and less than 90 degrees is placed on the side that will become the effective surface VSF of the magnet base material subassembly 45 (which refers to the surface among the four surfaces (in cross section) that make up the magnet base material subassembly 45 where magnetic flux should be generated in a concentrated manner), and a vertical magnet base material piece 30 cut in the cutting process SS40 with angles θ1 and θ2 each set within the range of 0 degrees or more and less than 45 degrees is placed on the side opposite to the side that will become the effective surface VSF, and these are then combined together and joined, glued, etc. to obtain the magnet base material subassembly 45. At this stage, the magnet base material pieces 20, 30 are not magnetized and no repulsive or attractive force is generated between them, so that the magnet base material pieces 20, 30 can be easily combined, joined, or adhered together.

[0124] 27, in the four-direction magnetization process SS85, a magnetic field in a first direction is applied to the effective surface VSF of the magnet matrix subassembly 45, and a magnetic field in a second direction is applied to the remaining three surfaces so as to surround the magnet matrix subassembly 45, thereby magnetizing the magnet matrix subassembly 45. In the example of Fig. 27, a positive magnetic field generated from the first magnetizing magnetic force source 731 is applied to the first surface SF1 which is the effective surface VSF of the magnet matrix subassembly 45, and negative magnetic fields generated from the second magnetizing magnetic force sources 732b, 732a, and 732c are applied to the remaining second surface SF2, third surface SF3, and fourth surface SF4, respectively, thereby obtaining a polar-anisotropic magnet 3N which emits magnetic field lines of positive polarity from the effective surface VSF. Furthermore, by appropriately switching the polarity of the first direction and second direction, which are the directions in which the magnetic field is applied, it is also possible to obtain a polar anisotropic magnet 3S in which the polarity of the magnetic field lines emanating from the effective surface VSF of the polar anisotropic magnet is reversed.

[0125] The detailed description of the four-direction magnetizing step SS85 other than the above is similar to that of the four-direction magnetizing step S40 of embodiment 1, and therefore the description of the four-direction magnetizing step S40 of embodiment 1 will be used and the description thereof will be omitted here. For reference, the magnetizing step described in embodiment 3 is composed of this four-direction magnetizing step SS85 in embodiment 5.

[0126] Through the above steps, the polar anisotropic magnet 3 can be obtained (this completes the method for producing a polar anisotropic magnet according to embodiment 5).

[0127] The magnet assembling process SS90 is a process for assembling a magnet assembly by combining the polar-anisotropic magnets 3N, 3S obtained in the four-directional magnetization process SS85. For example, polar-anisotropic magnets 3N, 3S, which have magnetic field lines of opposite polarity emanating from their effective surfaces VSF, are joined or adhered to each other at their side surfaces. In this case, the magnetic poles on the side surfaces of adjacent polar-anisotropic magnets 3N, 3S are opposite to each other (north and south poles), so they attract each other when joined or adhered, making assembly extremely easy. By going through the above steps, a cylindrical (annular) magnet assembly 100' shown at the bottom of FIG. 25 can be obtained (the above is the method for manufacturing a magnet assembly according to embodiment 5).

[0128] The manufacturing method of a magnet assembly and a manufacturing method of a polar-anisotropic magnet according to embodiment 5 combines the acquisition of magnet base material pieces 20, 30 using the parallel magnetic field and cutting technique of embodiments 2 to 4 with the magnetization by four-directional magnetization of embodiment 1. This makes it possible to simultaneously enjoy the advantages of acquiring the parallel magnetic field and cutting technique of embodiments 2 to 4 (no need for a formwork, high design freedom, etc.) and the advantages of four-directional magnetization of embodiment 1 (freedom from thickness design constraints, while being able to mass-produce polar-anisotropic magnets with both horizontal and vertical polar-anisotropic arrangements, etc.).

[0129] [Application example] The magnet assembly 100EX obtained in embodiment 2, the magnet assembly 100IN obtained in embodiment 3, and the composite magnet assembly 100 according to embodiment 4 constructed using them can be applied to a variety of product fields. For example, it is possible to construct a motor (see FIG. 12(a)) equipped with a rotor including the composite magnet assembly 100, a generator (see FIG. 12(b)) equipped with a rotor including the composite magnet assembly 100, an actuator (see FIG. 12(c)) equipped with a rotor including the composite magnet assembly 100, etc. Although it is preferable to use the composite magnet assembly 100 as a rotor on the rotating side, it can also be used as a stator on the fixed side. In this case, the term "rotor" in this specification can be read as "stator" and is applicable, and the configuration in this case is also included within the technical scope of the present invention.

[0130] Although the present invention has been described above based on the above embodiment, the present invention is not limited to the above embodiment and can be embodied in various forms without departing from the spirit of the present invention, and for example, the following modifications are also possible.

[0131] (1) Although the magnet assemblies 100EX and 100IN obtained by carrying out the second and third embodiments have been described assuming a cylindrical shape, the present invention is not limited to this. It is also possible to apply the present invention to a linear magnet assembly (not shown).

[0132] For example, in embodiments 2 and 3, the lengths of the cut line 20EX' of the planned outer diameter surface and the cut line 20IN' of the planned inner diameter surface can be set to be equal, and the surfaces that constitute the magnet blocks and that should become the effective H magnetic flux surfaces of the composite magnet assembly can be arranged so that they are approximately in the same plane between adjacent magnet blocks, thereby creating a linear magnet assembly. In this case, the only difference is that the magnet assembly is not cylindrical, but other configurations can be implemented in the same way as in Embodiments 2, 3, and 4. By combining such a linear magnet assembly of the first aspect with a magnet assembly of the second aspect, it is possible to obtain, for example, a linear composite magnet assembly 130 as shown in Fig. 29(a).

[0133] (2) By using a linear composite magnet assembly 130, it is also possible to configure a linear motor structure 550 including the composite magnet assembly 130 (see FIGS. 28, 29(b), and 29(c)). In this case, the term "rotor" in this specification can be read as "mover." Note that Fig. 28 is a schematic diagram shown to explain a linear motor structure 550 according to a modified example of the application example. Fig. 29 is a diagram shown to explain the details of the linear motor structure 550. Fig. 29(b) is a cross-sectional view of the linear motor structure 550 shown in Fig. 28 taken along a plane parallel to the longitudinal axis, and Fig. 29(c) is a cross-sectional view taken along line AA in Fig. 29(b). In the figure, reference numeral 552 denotes a rail, 553 denotes a movable body, 553a denotes a coil portion of the movable body, 70 and 80 denote magnet blocks, 130EX denotes an outer diameter side magnet assembly, 130IN denotes an inner diameter side magnet assembly, and 130 denotes a composite magnet assembly. [Explanation of symbols]

[0134] 1N, 1N', 1S, 1S', 2N, 2N', 2S, 2S', 3, 3N, 3S...Polar anisotropic magnet, 5...Material before magnetization, 6...Soft magnetic material, 10...Magnet base material, 11...First main surface, 12...Second main surface, 13a...Side A, 13b...Side B, 13c...Side C, 13d...Side D, 20, 30...Magnet base material piece, 20EX, 30EX...Planned outer diameter surface, 20EX', 30EX'...Cut line of planned outer diameter surface, 20IN, 30IN ...planned inner diameter surface, 20IN', 30IN'...cut line of planned inner diameter surface, 21, 24...joint side surface, 22...surface on one end side, 23...surface on the other end side, 40EX, 40IN...magnet base material assembly, 45...magnet base material subassembly, 50, 60, 70, 80...magnet block, 100, 100', 100EX, 100IN, 110, 120, 130EX, 130IN, 400EX, 400IN, 420L, 420U, 4 30,900,900EX,900IN...Magnet assembly, 100H...effective H magnetic flux surface, 100V...effective V magnetic flux surface, 130...composite magnet assembly, 400...cylindrical double structure magnet unit, 420...linear double structure magnet unit, 510...motor, 520...generator, 530...actuator, 550...linear motor structure, 552...rail, 553...moving body, 553a...moving body Coil part of the body, 710...form, 721...first magnetic source, 722, 722a, 722b, 722c...second magnetic source, 731...first magnetic source for magnetization, 732, 732a, 732b, 732c...second magnetic source for magnetization, 890, 810...form, 810a...inside of form, 820N, 820S, 830N, 830S, 840N, 840S...magnetic source, 905, 906, 907, 908...magnet, 905', 906'...base material

Claims

1. A method for manufacturing a polar anisotropic magnet having four faces facing four directions when viewed in cross section, comprising: a powder material preparation step of preparing powder material for magnets; When the surface where magnetic flux should be concentrated among the four surfaces is defined as the effective surface, a magnetic field molding process in which, from the outside of a mold corresponding to the desired shape of the polar anisotropic magnet, a magnetic field in a first direction is applied to the virtual effective surface, and a magnetic field in a second direction is applied to the remaining three surfaces, while the powder material is sequentially poured into the mold, and a magnet base material having a shape that matches the shape of the mold is molded; a four-directional magnetization process of magnetizing the magnetic material by applying a magnetic field in the first direction to the effective surface of the magnetic material and a magnetic field in the second direction to the remaining three surfaces of the magnetic material so as to surround the magnetic material obtained based on the magnetic base material; A method for producing a polar anisotropic magnet, comprising the steps of:

2. 2. The method for manufacturing a polar anisotropic magnet according to claim 1, In the magnetic field molding step, a first magnetic source is arranged so that a first magnetic pole faces the virtual effective surface, and second magnetic sources are arranged so that a second magnetic pole faces each of the remaining three surfaces other than the effective surface among the four surfaces, and a magnetic field in the first direction is applied to the virtual effective surface by the first magnetic source while a magnetic field in the second direction is applied to each of the remaining three surfaces by the second magnetic source; in the four-directional magnetizing step, a first magnetic source for magnetizing is arranged so that the first magnetic pole faces the effective surface, and a second magnetic source for magnetizing is arranged so that the second magnetic pole faces each of the remaining three surfaces, and then the first magnetic source for magnetizing and the second magnetic source for magnetizing are operated to apply a magnetic field in the first direction to the effective surface and a magnetic field in the second direction to the remaining three surfaces; A method for manufacturing a polar anisotropic magnet, characterized by:

3. 3. The method for manufacturing a polar anisotropic magnet according to claim 1 or 2, A method for manufacturing a polar anisotropic magnet, characterized in that it further includes a sintering / heat treatment step, between the magnetic field compacting step and the four-directional magnetizing step, of sintering and heat treating the magnet base material obtained by the magnetic field compacting step.

4. The method for producing a polar anisotropic magnet according to any one of claims 1 to 3, The intended shape of the polar anisotropic magnet is, when viewed in cross section, a divided ring shape obtained by dividing a circular ring into N equal parts (where N is a natural number of 2 or more). A method for manufacturing a polar anisotropic magnet, characterized by:

5. The method for producing a polar anisotropic magnet according to any one of claims 1 to 4, In the magnetic field molding step, a width of the first magnetic force source on a side where the first magnetic pole is disposed is set smaller than a width of the virtual effective surface, and / or In the four-directional magnetization step, a width of the first magnetic source for magnetization on a side where the first magnetic pole is disposed is set smaller than a width of the effective surface. A method for manufacturing a polar anisotropic magnet.

6. A polar anisotropic magnet having four faces facing four directions when viewed in cross section, When a surface of the four surfaces on which magnetic flux is to be generated in a concentrated manner is defined as an effective surface, one magnetic pole is disposed on the effective surface, and other magnetic poles are disposed on each of the remaining three surfaces of the four surfaces other than the effective surface, When viewed in cross section, there are no adhesive marks inside and the surface is continuously formed. A polar anisotropic magnet characterized by:

7. 7. The polar anisotropic magnet according to claim 6, When viewed in cross section, the ring has a divided ring shape obtained by dividing a circular ring into N equal parts (where N is a natural number of 2 or more). Polar anisotropic magnet characterized by

8. A magnet comprising a plurality of polar anisotropic magnets according to claim 6 or 7, A magnet assembly in which the polar anisotropic magnets are arranged and joined together so that the one magnetic pole and the other magnetic pole appear alternately.

9. 9. The magnet assembly according to claim 8, A magnet assembly characterized in that the polar anisotropic magnets are arranged in a circumferential direction and have a substantially cylindrical outer shape.

10. A motor having a rotor including the magnet assembly according to claim 9.

11. A generator comprising a rotor including the magnet assembly of claim 9.

12. An actuator comprising a rotor including the magnet assembly according to claim 9.

13. A method for manufacturing a cylindrical magnet assembly, comprising: a powder material preparation step of preparing powder material for magnets; a magnetic field molding process for molding a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, in which the powder material is poured into a mold corresponding to the shape of the magnet base material, and a unidirectional parallel magnetic field is applied from the side corresponding to the first main surface to the side corresponding to the second main surface outside the mold to mold the magnet base material; a cutting process in which, when a surface that will become the outer diameter surface of a magnet assembly when assembled is defined as a "planned outer diameter surface" and a surface that will become the inner diameter surface of the magnet assembly is defined as a "planned inner diameter surface," a cutting line for the planned outer diameter surface is set to be inclined at an angle θ1 with respect to the first main surface, and the magnet base material is cut along the cutting line for the planned outer diameter surface, and a cutting line for the planned inner diameter surface is set to be inclined at an angle θ2 with respect to the first main surface, and the magnet base material is cut along the cutting line for the planned inner diameter surface, thereby cutting out magnet base material pieces having at least the planned outer diameter surface and the planned inner diameter surface on their outer surfaces; an assembly step of assembling a plurality of the magnet matrix pieces together to form a magnet matrix assembly; a magnetizing step of applying a predetermined magnetic field to a predetermined position from outside the magnet matrix assembly to magnetize the magnet matrix assembly; A method for manufacturing a magnet assembly, comprising the steps of:

14. The method for manufacturing a magnet assembly according to claim 13, A method for manufacturing a magnet assembly, wherein cutting is performed so that the intended outer diameter surface and / or the intended inner diameter surface cut out in the cutting step is flat.

15. 15. The method for manufacturing a magnet assembly according to claim 13 or 14, A method for manufacturing a magnet assembly, wherein the cutting step is carried out by wire cutting.

16. The method for manufacturing a magnet assembly according to any one of claims 13 to 15, The method for manufacturing a magnet assembly, wherein the angle θ1 and the angle θ2 in the cutting step are each within a range of more than 45 degrees and less than 90 degrees.

17. The method for manufacturing a magnet assembly according to any one of claims 13 to 15, The method for manufacturing a magnet assembly, wherein the angle θ1 and the angle θ2 in the cutting step are each within a range of 0 degrees or more and less than 45 degrees.

18. The method for manufacturing a magnet assembly according to any one of claims 13 to 15, When the direction of each powder of the powder material aligned by carrying out the compacting step in the magnetic field is defined as the "axis of easy magnetization," a cutting step of cutting the magnet base material along the cutting line of the intended outer diameter surface and the cutting line of the intended inner diameter surface, the cutting line being set at an angle greater than 0 degrees and less than 45 degrees relative to the axis of easy magnetization;

19. The method for manufacturing a magnet assembly according to any one of claims 13 to 15, When the direction of each powder of the powder material aligned by carrying out the compacting step in the magnetic field is defined as the "axis of easy magnetization," a cutting step of setting a cut line on the intended outer diameter surface and a cut line on the intended inner diameter surface at an angle greater than 45 degrees and less than 90 degrees relative to the axis of easy magnetization, and cutting the magnet base material along the cut line on the intended outer diameter surface and the cut line on the intended inner diameter surface.

20. The method for manufacturing a magnet assembly according to any one of claims 13 to 15, the assembling step is a sub-assembly step of assembling at least four of the magnet base material pieces to form a magnet base material sub-assembly having four surfaces, In the sub-assembly step, when the surface among the four surfaces on which magnetic flux should be generated in a concentrated manner is defined as an effective surface, the horizontal magnet base material piece cut in the cutting step with the angles θ1 and θ2 each set within a range of more than 45 degrees and less than 90 degrees is placed on the side of the magnet base material sub-assembly that will become the effective surface, and the vertical magnet base material piece cut in the cutting step with the angles θ1 and θ2 each set within a range of 0 degrees or more and less than 45 degrees is placed on the side opposite to the side that will become the effective surface, the magnetizing step is a four-directional magnetizing step in which a magnetic field in a first direction is applied to the effective surface of the magnet matrix subassembly and a magnetic field in a second direction is applied to the remaining three surfaces of the magnet matrix subassembly so as to surround the magnet matrix subassembly, thereby magnetizing the magnet matrix subassembly; 2. A method for manufacturing a magnet assembly comprising:

21. A method for manufacturing a polar anisotropic magnet having four faces when viewed in cross section, comprising: a powder material preparation step of preparing powder material for magnets; a magnetic field molding process for molding a "magnet base material" having a first main surface and a second main surface opposite to the first main surface, in which the powder material is poured into a mold corresponding to the shape of the magnet base material, and a unidirectional parallel magnetic field is applied from the side corresponding to the first main surface to the side corresponding to the second main surface outside the mold to mold the magnet base material; a cutting process in which, when the surface that will become the outer diameter surface of the magnet assembly when the polar anisotropic magnet is assembled is defined as a "planned outer diameter surface," and the surface that will become the inner diameter surface of the magnet assembly is defined as a "planned inner diameter surface," a cutting line for the planned outer diameter surface is set to be inclined at an angle θ1 with respect to the first main surface, and the magnet base material is cut along the cutting line for the planned outer diameter surface, and a cutting line for the planned inner diameter surface is set to be inclined at an angle θ2 with respect to the first main surface, and the magnet base material is cut along the cutting line for the planned inner diameter surface, thereby cutting out magnet base material pieces having at least the planned outer diameter surface and the planned inner diameter surface on their outer surfaces; a sub-assembly process for assembling a magnet base material subassembly having four surfaces by combining at least four of the magnet base material pieces, in which, when one of the four surfaces on which magnetic flux should be generated intensively is defined as an effective surface, the horizontal magnet base material pieces cut in the cutting process so that the angles θ1 and θ2 are each set within a range of more than 45 degrees and less than 90 degrees are disposed on the side of the magnet base material subassembly that will become the effective surface, and the vertical magnet base material pieces cut in the cutting process so that the angles θ1 and θ2 are each set within a range of 0 degree or more and less than 45 degrees are disposed on the side opposite to the side that will become the effective surface; a four-directional magnetization step of magnetizing the magnet matrix subassembly by applying a magnetic field in a first direction to the effective surface of the magnet matrix subassembly and a magnetic field in a second direction to the remaining three surfaces of the magnet matrix subassembly so as to surround the magnet matrix subassembly; A method for producing a polar anisotropic magnet, comprising the steps of:

22. a magnet block having substantially flat outer and inner diameter surfaces, magnetized at a predetermined angle relative to the outer and inner diameter surfaces and parallel to a single direction; A magnet assembly comprising a plurality of said magnet blocks joined together via surfaces other than said outer diameter surface and said inner diameter surface.

23. the magnet assembly according to claim 8, wherein an angle of the magnetization direction with respect to the outer diameter surface and the inner diameter surface of each of the magnet blocks is a first angle; the magnet assembly according to claim 8, wherein the angle of the magnetization direction with respect to the outer diameter surface and the inner diameter surface of each magnet block is a second angle; Equipped with A composite magnet assembly in which the magnet assembly of the first aspect is arranged on the side that should be the effective H magnetic flux surface of the composite magnet assembly, and the magnet assembly of the second aspect is arranged on the side that should be the effective V magnetic flux surface of the composite magnet assembly, and they are joined together.

24. 24. The composite magnet assembly of claim 23, A composite magnet assembly is formed by joining N magnet blocks together, and the outer and inner circumferential sides of the magnet assemblies form a cylindrical shape with an N-sided polygon. However, when nps=2: the number of same poles, npNS=2: the number of different poles, and ns: the number of sets (a natural number of 1 or more), N is a natural number that satisfies the relationship N=nps·npNS·ns.

25. A motor having a rotor including the composite magnet assembly of claim 24.

26. 25. An electric generator comprising a rotor including the composite magnet assembly of claim 24.

27. An actuator comprising a rotor including the magnet assembly of claim 24.

28. 24. The composite magnet assembly of claim 23, A linear composite magnet assembly in which the surfaces of the magnet blocks that constitute the composite magnet assembly are arranged so that the surfaces that should become the effective H magnetic flux surfaces of the composite magnet assembly are substantially flush with each other between the adjacent magnet blocks.

29. A linear motor structure comprising the composite magnet assembly of claim 28.

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