Method for manufacturing a ring magnet, rotor, motor, blower, and refrigeration device

Abstract

The present invention provides a method for manufacturing a ring magnet that can increase the magnetic force of the ring magnet, as well as a rotor, motor, blower, and refrigeration apparatus. [Solution] In the method for manufacturing a ring magnet, a mold 60 is used. The mold 60 comprises a mold body 70 having a cylindrical cavity 71, and a magnetic field generating unit 80 which is arranged on the inner or outer circumferential surface side of the cavity 71 in the radial direction and generates a magnetic field within the cavity 71. The method for manufacturing a ring magnet includes a molding step of forming a ring magnet by injecting a bonded magnet material 51a containing magnetically anisotropic magnetic powder into the cavity 71. In the molding step, the bonded magnet material 51a is injected with a magnetic member 52 containing a soft magnetic material placed in the cavity 71.

Description

Technical Field

[0005] ,

[0001] The present disclosure relates to a method for manufacturing a ring magnet, a rotor, a motor, a blower, and a refrigeration device.

Background Art

[0002] A method of manufacturing a ring magnet by injecting a bonded magnet material into a cylindrical cavity is known (for example, Patent Document 1). The bonded magnet material injected into the cavity is oriented by the magnetic flux of a magnetic field generating portion that generates a magnetic field in the cavity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the bonded magnet material in the cavity, since the magnetic flux of the magnetic field generating portion decreases as the distance from the magnetic pole of the magnetic field generating portion increases, it is difficult for the easy magnetization axes of the magnetic powder to be aligned. Therefore, it is difficult to increase the magnetic force of the ring magnet formed by curing the bonded magnet material.

Means for Solving the Problems

[0005] A first aspect of a method for manufacturing a ring magnet that solves this problem is a method for manufacturing a ring magnet, comprising a mold body having a cylindrical cavity, and a magnetic field generating unit disposed on the inner or outer circumferential surface side of the cavity in the radial direction and generating a magnetic field within the cavity, wherein the molding step includes a molding step of forming the ring magnet by injecting a bonded magnet material containing magnetic anisotropic magnetic powder into the cavity, the magnetic field generating unit having magnetic poles arranged in the circumferential direction of the cavity, and in the molding step, the bonded magnet material is injected with a magnetic member containing a soft magnetic material disposed in the cavity.

[0006] In this configuration, during the molding process, the magnetic flux from the magnetic field generator is attracted to the magnetic member, thereby increasing the magnetic flux passing through the bonded magnet material. Because the magnetic member increases the magnetic flux density near it, the easy magnetization axis of the magnetic powder in the bonded magnet material aligns more easily with the magnetic flux from the magnetic field generator near the magnetic member. Therefore, the magnetic force of the ring magnet can be increased.

[0007] The method for manufacturing a ring magnet according to the second aspect includes, in the method for manufacturing a ring magnet according to the first aspect, a placement step of placing the magnetic member in the cavity, and after the placement step, the molding step is performed.

[0008] This configuration allows for the molding of a ring magnet in which the bonded magnet and the magnetic material are integrally molded.

[0009] The third aspect of the method for manufacturing a ring magnet is that, in the method for manufacturing a ring magnet according to the first or second aspect, the mold body is provided with a mounting portion to which the magnetic member can be detachably attached.

[0010] With this configuration, since the magnetic member is attached to the mounting part of the mold body, it is possible to suppress the movement of the magnetic member when the bonded magnet material is injected during the molding process.

[0011] The fourth aspect of the method for manufacturing a ring magnet is the method for manufacturing a ring magnet according to the first aspect, wherein the magnetic member is fixed to the mold body, and in the molding step, the bonded magnet material is injected with the magnetic member fixed to the mold body.

[0012] With this configuration, the magnetic component is fixed to the mold body, so it does not move when the bonded magnet material is injected during the molding process. Therefore, ring magnets can be manufactured with high precision.

[0013] The fifth aspect of the method for manufacturing a ring magnet is the method for manufacturing a ring magnet according to the fourth aspect, wherein a recess in the shape of the magnetic member is formed in the ring magnet.

[0014] This configuration allows for the formation of recesses in the shape of magnetic material within the bonded magnet.

[0015] The sixth aspect of the method for manufacturing a ring magnet is a method for manufacturing a ring magnet according to any one of the first to fifth aspects, wherein the magnetic member is arranged such that the longitudinal direction of the magnetic member is aligned with the cylindrical axis direction of the cavity.

[0016] In this configuration, the magnetic member is positioned such that its longitudinal direction aligns with the cylindrical axis direction of the cavity. Therefore, the magnetic member can increase the magnetic flux passing through the bonded magnet material in the cylindrical axis direction.

[0017] The method for manufacturing a ring magnet according to the seventh aspect is the method for manufacturing a ring magnet according to any one of the methods for manufacturing a ring magnet according to the first aspect to the sixth aspect, wherein the magnetic member is arranged in the cavity between the magnetic poles that are adjacent in the circumferential direction.

[0018] With this configuration, the magnetic member is positioned between adjacent magnetic poles in the circumferential direction, which allows the magnetic flux between adjacent magnetic poles on either side of the magnetic member to be attracted towards the vicinity of the magnetic member.

[0019] The manufacturing method of the ring magnet from the eighth perspective is the manufacturing method of the ring magnet according to any one of the first to third perspectives, wherein the magnetic member is disposed at an end portion in the cylinder axis direction of the cavity in the cavity.

[0020] According to this configuration, the magnetic flux density passing through the bonded magnet material can be increased at the end portion in the cylinder axis direction in the cavity.

[0021] The rotor from the ninth perspective for solving this problem is a rotor of a motor, the rotor includes a cylindrical ring magnet, and the ring magnet is a bonded magnet including magnetically anisotropic magnetic powder in which a magnetic member containing a soft magnetic material is integrally formed.

[0022] According to this configuration, the magnetic flux passing through the ring magnet is attracted to the magnetic member. As a result, the magnetic flux density near the magnetic member in the ring magnet can be increased compared to a ring magnet that does not include the magnetic member. Therefore, the magnetic force of the ring magnet can be increased.

[0023] The rotor from the tenth perspective is the rotor from the ninth perspective, wherein the magnetic member is disposed in the ring magnet such that the longitudinal direction of the magnetic member is along the cylinder axis direction of the ring magnet.

[0024] According to this configuration, the magnetic member is disposed such that the longitudinal direction of the magnetic member is along the cylinder axis direction of the ring magnet. Therefore, the magnetic flux density near the magnetic member in the ring magnet can be increased over the cylinder axis direction by the magnetic member.

[0025] [[ID=Z3]] The rotor from the eleventh perspective is the rotor from the ninth or tenth perspective, wherein the magnetic member is disposed in the ring magnet between adjacent magnetic poles in the circumferential direction of the ring magnet.

[0026] According to this configuration, the magnetic member is disposed between adjacent magnetic poles in the circumferential direction in the ring magnet. Therefore, the magnetic flux between adjacent magnetic poles sandwiching the magnetic member can be attracted near the magnetic member.

[0027] In the rotor of the 12th aspect, in the rotor of the 9th aspect, the magnetic member is disposed at an end portion of the ring magnet in the cylinder axis direction of the ring magnet.

[0028] According to this configuration, the magnetic flux density at the end portion of the ring magnet in the cylinder axis direction can be increased.

[0029] The motor of the 13th aspect that solves this problem includes any one rotor from the 9th aspect to the 12th aspect and a stator.

[0030] According to this configuration, since the magnetic force of the ring magnet of the rotor is improved, the rotational characteristics of the motor such as rotational torque and rotational accuracy can be improved.

[0031] The blower of the 14th aspect that solves this problem includes the motor of the 13th aspect and a blower device driven by the motor.

[0032] According to this configuration, since the blower device is driven by a motor with improved rotational characteristics, an appropriate rotational force can be obtained for the blower device.

[0033] The refrigerator of the 15th aspect that solves this problem includes the motor described in the 13th aspect.

[0034] According to this configuration, the refrigerator can be stably driven by a motor with improved rotational characteristics.

Brief Description of Drawings

[0035] [Figure 1] It is a schematic diagram of a blower according to the first embodiment. [Figure 2] It is a cross-sectional view of a cross-section along the cylinder axis direction of a ring magnet in the motor of FIG. 1. [Figure 3] It is a plan view of the ring magnet of FIG. 2 as viewed from the cylinder axis direction on the side where the gate mark is formed. [Figure 4]Figure 3 is a cross-sectional view of the ring magnet, perpendicular to the direction of the cylindrical axis. [Figure 5] Figure 3 is a schematic diagram of the mold used to manufacture the ring magnet. [Figure 6] This is a cross-sectional view of the mold shown in Figure 5, along the line D6-D6. [Figure 7] Figure 5 is a perspective view of the mounting portion of the mold body. [Figure 8] Figure 3 is a first schematic diagram showing a part of the arrangement process in the manufacturing method of the ring magnet. [Figure 9] This is a second schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet shown in Figure 3. [Figure 10] This is a third schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet shown in Figure 3. [Figure 11] Figure 3 is a first schematic diagram showing a part of the molding process in the manufacturing method of the ring magnet. [Figure 12] This is a second schematic diagram showing a part of the molding process in the manufacturing method of the ring magnet shown in Figure 3. [Figure 13] Figure 3 is a first schematic diagram showing a part of the removal process in the manufacturing method of the ring magnet. [Figure 14] This is a second schematic diagram showing a part of the removal process in the manufacturing method of the ring magnet shown in Figure 3. [Figure 15] Figure 3 is a schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 16] This is a first schematic diagram showing the orientation of the easy magnetization axis of magnetic powder in a conventional ring magnet bonded magnet. [Figure 17] This is a plan view of the ring magnet according to the second embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 18] Figure 17 shows a cross-sectional view of the ring magnet perpendicular to the cylindrical axis. [Figure 19] Figure 17 is a schematic diagram of the mold used to manufacture the ring magnet. [Figure 20] This is a cross-sectional view of the mold shown in Figure 19, along the D20-D20 line. [Figure 21] Figure 17 is a schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 22] This is a cross-sectional view of the ring magnet along the cylindrical axis direction in the motor according to the third embodiment. [Figure 23] Figure 22 is a bottom view of the ring magnet, seen from the cylindrical axis direction on the side where no gate marks have been formed. [Figure 24] Figure 23 shows a cross-sectional view of the ring magnet along the line D24-D24. [Figure 25] Figure 23 is a first schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 26] Figure 23 is a second schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 27] This is a third schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet shown in Figure 23. [Figure 28] Figure 23 is a first schematic diagram showing a part of the molding process in the manufacturing method of the ring magnet. [Figure 29] Figure 23 is a second schematic diagram showing a part of the molding process in the manufacturing method of the ring magnet. [Figure 30] Figure 23 is a first schematic diagram showing a part of the removal process in the manufacturing method of the ring magnet. [Figure 31] Figure 23 is a second schematic diagram showing a part of the removal process in the manufacturing method of the ring magnet. [Figure 32] Figure 23 is a first schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 33] Figure 23 is a second schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 34] This is a third schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in the bonded ring magnet shown in Figure 23. [Figure 35] This is a second schematic diagram showing the orientation of the easy magnetization axis of magnetic powder in a conventional ring magnet bonded magnet. [Figure 36]This is a third schematic diagram showing the orientation of the easy magnetization axis of magnetic powder in a conventional ring magnet bonded magnet. [Figure 37] This is a plan view of a ring magnet according to a first modification of the first embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 38] This is a cross-sectional view of a ring magnet according to a second modified example of the first embodiment, with a cross-section perpendicular to the cylindrical axis direction. [Figure 39] Figure 38 is a schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 40] This is a cross-sectional view of a ring magnet according to a third modified example of the first embodiment, with a cross-section perpendicular to the cylindrical axis. [Figure 41] Figure 40 is a schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 42] This is a cross-sectional view of a ring magnet according to a fourth modification of the first embodiment, with a cross-section perpendicular to the cylindrical axis direction. [Figure 43] Figure 42 is a schematic diagram showing the orientation of the easy magnetization axis of the magnetic powder in a bonded ring magnet. [Figure 44] This is a perspective view of the mounting portion of the mold body of the molding die used in the manufacturing method of a ring magnet according to a fifth modified example of the first embodiment. [Figure 45] This is a plan view of the mounting portion of the mold body of the molding die used in the manufacturing method of a ring magnet according to the sixth modification of the first embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 46] Figure 45 is a first schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 47] Figure 45 is a second schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 48] This is a plan view of the mounting portion of the mold body of the molding die used in the method for manufacturing a ring magnet according to the seventh modification of the first embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 49] Figure 48 is a first schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 50] Figure 48 is a second schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 51] This is a plan view of the mounting portion of the mold body of the molding die used in the method for manufacturing a ring magnet according to the eighth modification of the first embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 52] This is a plan view of a ring magnet according to the first modified example of the second embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 53] This is a cross-sectional view of a ring magnet according to a second modified example of the second embodiment, with the cross-section perpendicular to the cylindrical axis. [Figure 54] This is a cross-sectional view of a ring magnet according to a third modified example of the second embodiment, with the cross-section perpendicular to the cylindrical axis. [Figure 55] This is a cross-sectional view of a ring magnet according to a fourth modification of the second embodiment, with a cross-section perpendicular to the cylindrical axis. [Figure 56] This is a bottom view of a ring magnet according to the first modification of the third embodiment, as seen from the cylindrical axis direction on the side where no gate marks are formed. [Figure 57] This is a bottom view of a ring magnet according to a second modification of the third embodiment, viewed from the cylindrical axis direction on the side where no gate marks are formed. [Figure 58] This is a bottom view of a ring magnet according to a third modification of the third embodiment, viewed from the cylindrical axis direction on the side where no gate marks are formed. [Figure 59] This is a bottom view of a ring magnet according to a fourth modification of the third embodiment, viewed from the cylindrical axis direction on the side where no gate marks are formed. [Figure 60] This is a bottom view of a ring magnet according to a fifth modification of the third embodiment, viewed from the cylindrical axis direction on the side where no gate marks are formed. [Figure 61] This is a plan view of a ring magnet according to a sixth modification of the third embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 62] Figure 61 is a cross-sectional view of the ring magnet along the line D62-D62. [Figure 63]This is a plan view of a ring magnet according to the seventh modification of the third embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 64] This is a plan view of a ring magnet according to the eighth modified example of the third embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 65] This is a first schematic diagram showing a part of the arrangement step in a method for manufacturing a ring magnet according to a ninth modified example of the third embodiment. [Figure 66] Figure 65 is a second schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 67] This is a plan view of a ring magnet manufactured by the manufacturing method of a ring magnet according to the ninth modified example of the third embodiment, as seen from the cylindrical axis direction on the side where the gate mark is formed. [Figure 68] This is a first schematic diagram showing a part of the arrangement step in a method for manufacturing a ring magnet according to a tenth modified example of the third embodiment. [Figure 69] Figure 68 is a second schematic diagram showing part of the arrangement process in the manufacturing method of the ring magnet. [Figure 70] This is a bottom view of a ring magnet manufactured by the method for manufacturing a ring magnet according to the tenth modified example of the third embodiment. [Modes for carrying out the invention]

[0036] <First Embodiment> A method for manufacturing the blower 1, motor 20, rotor 40, and ring magnet 50 according to the first embodiment will be described with reference to Figures 1 to 16.

[0037] <Blower> As shown in Figures 1 and 2, the blower 1 is installed, for example, in the indoor unit of an air conditioner. The air conditioner performs air conditioning operations such as cooling, heating, and dehumidifying the room. The blower 1 performs functions such as drawing in and blowing out air.

[0038] The blower 1 comprises a blower device 10 and a motor 20. The blower device 10 is driven by the motor 20. The blower device 10 has, for example, a cylindrical cross-flow fan 11. Air is drawn in and blown out by the rotation of the cross-flow fan 11.

[0039] <motor> An example of the motor 20 is an outer rotor type motor. The motor 20 comprises a stator 30 and a rotor 40.

[0040] The stator 30 includes a coil 31, a coil holder 32, a cylindrical first cylindrical portion 33, a disc portion 34, and a stator core 35. The coil 31 is wound around the stator core 35. The stator core 35 is made of a material including a soft magnetic material. The stator core 35 is constructed, for example, by laminating electromagnetic steel sheets in the cylindrical axis direction A1. The coil holder 32 holds the coil 31. The first cylindrical portion 33 is located on the outer circumferential surface side of the coil holder 32. The disc portion 34 connects the coil holder 32 and the first cylindrical portion 33. The coil holder 32, the first cylindrical portion 33, and the disc portion 34 are, for example, made of resin. The coil holder 32, the first cylindrical portion 33, and the disc portion 34 are integrally molded. The stator 30 is provided with a cylindrical arrangement space. The cylindrical arrangement space is the space located between the coil holding portion 32 and the first cylindrical portion 33 of the stator 30. Note that the coil holding portion 32, the first cylindrical portion 33, and the disc portion 34 may be molded individually.

[0041] <Rotor> The rotor 40 includes a cylindrical ring magnet 50. One end of the ring magnet 50 in the cylindrical axis direction A1 is located in a cylindrical arrangement space. The other end of the ring magnet 50 in the cylindrical axis direction A1 is attached to a magnet holder 41, which will be described later.

[0042] The rotor 40 includes, in addition to the ring magnet 50, a magnet holder 41, a second cylindrical portion 42, and a rotating shaft 43. In the cylindrical axis direction A1 of the ring magnet 50, the magnet holder 41 has a first surface on the blower 10 side and a second surface on the opposite side of the first surface. The magnet holder 41 holds the ring magnet 50 on the second surface. The magnet holder 41 is made of, for example, a resin material. The second cylindrical portion 42 is located on the outer circumference side of the ring magnet 50. The rotating shaft 43 is fixed to the magnet holder 41. The rotating shaft 43 is located inside the ring magnet 50. The rotating shaft 43 is located on the inner circumference side of the coil holder 32 of the stator 30. A bearing 21 is positioned between the rotating shaft 43 and the coil holder 32. The rotor 40 is supported by the stator 30 via the bearing 21. The cross-flow fan 11 of the blower 10 is fixed to the first surface of the magnet holder 41.

[0043] When current flows through the coil 31 of the stator 30, a magnetic field is generated. This magnetic field causes the rotor 40, which is equipped with a ring magnet 50, to rotate. This, in turn, causes the cross-flow fan 11 of the blower 10, which is fixed to the magnet holder 41 of the rotor 40, to rotate.

[0044] <Ring Magnet> As shown in Figures 2 to 4, the ring magnet 50 is a cylindrical body. The ring magnet 50 is a polar anisotropic magnet having two or more magnetic poles arranged in the circumferential direction A2 on its inner or outer circumferential surface. In one example, the ring magnet 50 has two or more magnetic poles arranged in the circumferential direction A2 on its inner circumferential surface, and no magnetic poles on its outer circumferential surface. In another example, the ring magnet 50 has two or more magnetic poles arranged in the circumferential direction A2 on its outer circumferential surface, and no magnetic poles on its inner circumferential surface. In this embodiment, the ring magnet 50 has two or more magnetic poles arranged in the circumferential direction A2 on its inner circumferential surface. The ring magnet 50 is a bonded magnet 51. The bonded magnet 51 contains magnetically anisotropic magnetic powder. Examples of materials for the magnetic powder include fine powdered or granular ferrite-based magnets or rare-earth-based magnets. The bonded magnet 51 contains a binder such as nylon resin or PPS (polyphenylene sulfide) resin. A bonded magnet 51 is formed when a bonded magnet material 51a (see Figure 11), which is a mixture of magnetically anisotropic magnetic powder and a molten binder, hardens.

[0045] In this embodiment, the ring magnet 50 is integrally molded with a bonded magnet 51 and a magnetic member 52. The magnetic member 52 includes a soft magnetic material. The magnetic member 52 is composed of a soft magnetic material. Examples of soft magnetic materials include electromagnetic steel sheets, compacted magnetic cores, nanocrystalline alloys, amorphous alloys, and cast iron.

[0046] The magnetic member 52 is configured in a plate shape. In the ring magnet 50, the magnetic member 52 is positioned such that its longitudinal direction is aligned with the cylindrical axis direction A1 of the ring magnet 50. The magnetic member 52 is positioned such that its longitudinal direction is approximately parallel to the cylindrical axis direction A1. In this embodiment, the length of the magnetic member 52 in the radial direction A3 is shorter than the length of the ring magnet 50 in the radial direction A3. In this embodiment, the end face of the magnetic member 52 facing radially outward is separated from the outer circumferential surface of the ring magnet 50. The end face of the magnetic member 52 facing radially A3 is separated from the outer circumferential surface of the ring magnet 50 that does not have a magnetic pole, among the outer and inner circumferential surfaces. In this embodiment, the end face of the magnetic member 52 facing radially A3 is separated from the outer circumferential surface of the ring magnet 50 that does not have a magnetic pole.

[0047] The magnetic members 52 are positioned on the magnetic flux extending from one adjacent magnetic pole to the other, with the magnetic member 52 in between. In this embodiment, the magnetic members 52 are positioned between adjacent magnetic poles in the circumferential direction A2 of the ring magnet 50. The magnetic members 52 do not overlap with the magnetic poles of the ring magnet 50 in the radial direction A3. The number of magnetic members 52 corresponds to the number of magnetic poles of the ring magnet 50. In this embodiment, the number of magnetic members 52 is equal to the number of magnetic poles of the ring magnet 50. Each of the multiple magnetic members 52 is positioned apart from the others.

[0048] The ring magnet 50 has a first end face 53 and a second end face 54 opposite to the first end face 53 in the cylindrical axis direction A1. In the example of Figure 2, the first end face 53 of the ring magnet 50 is attached to the magnet holder 41. The first end face 53 is the face at one end of the ring magnet 50 in the cylindrical axis direction A1. In this embodiment, the magnetic member 52 is not exposed to the first end face 53 of the ring magnet 50. The first end face 53 of the ring magnet 50 is formed by the bonded magnet 51. A gate mark 55 is formed on the first end face 53. The gate mark 55 is the mark left when the ring magnet 50 was separated from the bonded magnet 51 in the runner 92 during manufacturing. The second end face 54 is the face at the other end of the ring magnet 50 in the cylindrical axis direction A1. The second end face 54 is the face at the end of the ring magnet 50 opposite to the first end face 53. In this embodiment, the magnetic member 52 is exposed to the second end face 54 of the ring magnet 50. The second end face 54 of the ring magnet 50 is formed by the bonded magnet 51. No gate marks 55 are formed on the second end face 54. In the cavity 71 of the mold body 70, which will be described later, the first end face 53 is located at the opening of the cavity 71, and the second end face 54 faces the bottom surface 71a of the cavity 71.

[0049] <How to manufacture a ring magnet> The manufacturing method for the ring magnet 50 will be described with reference to Figures 5 to 14. The manufacturing method for the ring magnet 50 includes an arrangement step, a molding step, an extraction step, and a magnetization step. A molding die 60 is used in the manufacturing of the ring magnet 50.

[0050] [Mold] As shown in Figures 5 and 6, the mold 60 comprises a mold body 70 and a magnetic field generating unit 80. The mold body 70 has a cylindrical cavity 71. The mold body 70 is made of a non-magnetic material. An example of a non-magnetic material is non-magnetic stainless steel. The non-magnetic materials described later are similar. A magnetic member 52 is placed inside the cavity 71 of the mold body 70. The magnetic member 52 is positioned so as not to obstruct the cavity 71 in the circumferential direction A2 so that the bonded magnet material 51a can flow inside the cavity 71 during the molding process (see Figure 11). The length of the magnetic member 52 in the radial direction A3 is shorter than the length of the cavity 71 in the radial direction A3.

[0051] As shown in Figure 7, the mold body 70 is provided with a mounting portion 72. The mounting portion 72 is configured to allow the magnetic member 52 to be removably attached. The mounting portion 72 is configured so that the molded ring magnet 50 can be easily separated from the magnetic member 52 by being pulled in the cylindrical axis direction A1. The mounting portion 72 is further configured to hold the magnetic member 52 so that the magnetic member 52 does not shift position within the cavity 71 due to forces applied to the magnetic member 52 in the circumferential direction A2 and the radial direction A3. The mounting portion 72 engages with the magnetic member 52 in the circumferential direction A2 and the radial direction A3, but does not substantially engage in the cylindrical axis direction A1.

[0052] The mounting portion 72 is provided on the bottom surface 71a or side surface 71b within the cavity 71. The mounting portion 72 is positioned between the magnetic poles of adjacent magnetic field generating portions 80 in the circumferential direction A2.

[0053] The mounting portion 72 has, for example, a pole 72a. The magnetic member 52 has, for example, a through hole 52a. The magnetic member 52 is attached to the mounting portion 72 by inserting the pole 72a of the mounting portion 72 through the through hole 52a of the magnetic member 52. Note that in the examples of Figures 5 and 6, the pole 72a is omitted.

[0054] As shown in Figure 6, the magnetic field generating unit 80 generates a magnetic field within the cavity 71. The magnetic field generating unit 80 is positioned on either the inner or outer circumferential surface side of the cavity 71 in the radial direction A3. In this embodiment, the magnetic field generating unit 80 is positioned on the inner circumferential surface side of the cavity 71 in the radial direction A3. The magnetic field generating unit 80 is positioned inside the mold body 70. A sleeve, which constitutes the inner circumferential surface of the cavity 71, may be positioned between the outer circumferential surface of the magnetic field generating unit 80 and the mold body 70, separately from the mold body 70.

[0055] The magnetic field generating unit 80 has magnetic poles arranged in a line in the circumferential direction A2 of the cavity 71. The magnetic poles of the magnetic field generating unit 80 are arranged on the inner or outer circumferential surface of the magnetic field generating unit 80. In the manufacture of the ring magnet 50 of this embodiment, the magnetic poles of the magnetic field generating unit 80 are arranged on the outer circumferential surface of the magnetic field generating unit 80. Multiple magnetic poles are formed at regular intervals on the outer circumferential surface of the magnetic field generating unit 80. Specifically, north poles and south poles are formed alternately at regular intervals on the outer circumferential surface of the magnetic field generating unit 80. The number of magnetic poles of the magnetic field generating unit 80 corresponds to the number of magnetic poles of the manufactured ring magnet 50. The number of magnetic poles of the magnetic field generating unit 80 is, for example, the same as the number of magnetic poles of the manufactured ring magnet 50. In the example of Figure 4, the magnetic field generating unit 80 has 8 magnetic poles. In this embodiment, the magnetic field generating unit 80 comprises multiple permanent magnets arranged in a line in the circumferential direction A2 of the cavity 71. The magnetic field generating unit 80 may also include electromagnets.

[0056] As shown in Figure 5, the mold 60 includes a movable part 90. The movable part 90 moves relative to the mold body 70, which is held in a fixed position. The movable part 90 is made of a non-magnetic material. Inside the movable part 90, a spool 91, a runner 92, and a gate 93 are formed. The spool 91 is configured to into which bonded magnetic material 51a is injected (see Figure 11). The runner 92 connects the spool 91 and the gate 93. The gate 93 is an opening that connects to the cavity 71 of the mold body 70.

[0057] As shown in Figure 6, the movable part 90 is provided with a plurality of gates 93. Each of the plurality of gates 93 is positioned in the same location as each of the magnetic poles of the magnetic field generating part 80 in the circumferential direction A2. The gates 93 are positioned between adjacent mounting parts 72 in the circumferential direction A2.

[0058] [Manufacturing method] Next, the method for manufacturing the ring magnet 50 will be described. The method for manufacturing the ring magnet 50 includes, as described above, a placement step, a molding step, a removal step, and a magnetization step. Figure 8 shows a cross-section of the mold 60 along the line D8-D8 in Figure 6. As shown in Figure 8, in the placement process, the magnetic member 52 is placed in the cavity 71. The magnetic member 52 is placed in the cavity 71 by attaching the magnetic member 52 to the mounting portion 72 of the mold body 70. In this embodiment, the magnetic member 52 is positioned such that the end face of the magnetic member 52 facing radially outward is away from the outer circumferential surface of the cavity 71. The magnetic member 52 is positioned such that the end face of the magnetic member 52 facing radially A3 that is farther from the magnetic field generating portion 80 is away from the inner or outer circumferential surface of the cavity 71. In this embodiment, the magnetic member 52 is positioned such that the end face of the magnetic member 52 facing radially A3 that is farther from the magnetic field generating portion 80 is away from the outer circumferential surface of the cavity 71.

[0059] The magnetic member 52 is positioned such that its longitudinal direction aligns with the cylindrical axis direction A1 of the cavity 71. The cylindrical axis direction A1 of the cavity 71 coincides with the cylindrical axis direction A1 of the ring magnet 50 manufactured by this manufacturing method.

[0060] In the manufacturing method of the ring magnet 50 of this embodiment, a molding process is performed after the arrangement process. That is, when the bonded magnet material 51a is injected into the cavity 71 during the molding process, the magnetic member 52 is placed in the cavity 71.

[0061] Figure 9 shows the mold body 70 with magnetic members 52 arranged in the cavity 71. As shown in Figure 9, the magnetic members 52 are arranged in the cavity 71 between the magnetic poles of adjacent magnetic field generating units 80 in the circumferential direction A2. The number of magnetic members 52 is the same as the number of magnetic poles of the magnetic field generating units 80.

[0062] As shown in Figure 10, with the magnetic member 52 placed in the cavity 71, the movable part 90 is placed on the mold body 70.

[0063] In the molding process shown in Figures 11 and 12, the ring magnet 50 is formed by injecting the bonded magnet material 51a into the cavity 71. In the molding process, the bonded magnet material 51a is injected with the magnetic member 52 already placed in the cavity 71. As shown in Figure 11, the bonded magnet material 51a is injected into the spool 91 of the movable part 90, then guided to the gate 93 by the runner 92, and flows into the cavity 71 after passing through the gate 93.

[0064] The bonded magnet material 51a contains magnetically anisotropic magnetic powder. The magnetic powder has an easy magnetization axis. The length of the magnetic powder in a second direction perpendicular to the easy magnetization axis is longer than the length of the magnetic powder in a first direction along the easy magnetization axis. In other words, the magnetic powder is flattened. The easy magnetization axis of the magnetic powder of the bonded magnet material 51a that flows into the cavity 71 is aligned with the flow direction of the bonded magnet material 51a. Note that the magnetic powder of the bonded magnet material 51a injected during the molding process is not magnetized.

[0065] While the easy magnetization axis of the magnetic powder is aligned with the flow direction of the bonded magnet material 51a, the magnetic powder is also affected by the magnetic field of the magnetic field generating unit 80. The magnetic field of the magnetic field generating unit 80 forces the magnetic powder so that its easy magnetization axis aligns with the magnetic flux of the magnetic field generating unit 80.

[0066] As shown in Figure 12, the bonded magnet 51 is formed in the cavity 71 by the hardening of the bonded magnet material 51a within the cavity 71.

[0067] The removal process shown in Figures 13 and 14 is performed after the molding process. In the removal process, the ring magnet 50 is removed from the mold 60. As shown in Figure 13, after the bonded magnet material 51a has hardened, the movable part 90 is removed from the mold body 70. At this time, the bonded magnet 51 in the cavity 71 and the bonded magnet 51 in the runner 92 are separated. As a result, gate marks 55 are formed on the bonded magnet 51 of the ring magnet 50 (see Figure 3).

[0068] As shown in Figure 14, after removing the movable part 90 from the mold body 70, the ring magnet 50 is removed from the cavity 71. At this time, since the magnetic member 52 is integrally molded with the bonded magnet 51 of the ring magnet 50, the magnetic member 52 is detached from the mounting part 72. After the removal process, a magnetization process is performed. In the magnetization process, the ring magnet 50 is magnetized. Before magnetizing the ring magnet 50, the ring magnet 50 may be demagnetized.

[0069] <Operation of the Embodiment> The first operation of this embodiment will now be described. In the manufacturing method of the ring magnet 50, the magnetic member 52 is placed in the cavity 71 of the mold body 70 before the bonded magnet material 51a is injected into the cavity 71. The magnetic member 52 placed in the cavity 71 has lower magnetic resistance than the surrounding area of ​​the magnetic member 52. Since magnetic flux easily passes through areas with low magnetic resistance, the magnetic flux of the magnetic field generating unit 80, which would pass through the surrounding area if the magnetic member 52 were not placed, is attracted to the magnetic member 52 so that it passes through the magnetic member 52. By placing the magnetic member 52 in the cavity 71, the magnetic flux of the magnetic field generating unit 80 within the cavity 71 can be controlled. As a result, by placing the magnetic member 52 in the cavity 71, the orientation of the easy magnetization axis of the magnetic powder of the bonded magnet 51 can be controlled.

[0070] The second operation of this embodiment will now be described. Figure 16 shows an example of a conventional ring magnet 100 when molded without placing a magnetic member 52 in the cavity 71. The white arrows in the figure indicate the direction along which the easy magnetization axis of the magnetic powder of the bonded magnet 51 aligns. S and N in Figure 16 indicate the magnetic poles of the conventional ring magnet 100. Near the south pole, the easy magnetization axis aligns radially in A3. As you move from near the south pole towards the midpoint between the south and north poles, the easy magnetization axis tilts radially in A2, and near the midpoint between the south and north poles, the easy magnetization axis aligns radially in A2. Then, as you move from near the midpoint between the south and north poles towards the north pole, the easy magnetization axis tilts radially in A3, and near the north pole, the easy magnetization axis aligns radially in A3.

[0071] When a conventional ring magnet 100 is manufactured without placing a magnetic member 52 in the cavity 71, the magnetic flux of the magnetic field generating unit 80 weakens as it moves away from the magnetic field generating unit 80, resulting in a lower orientation ratio near the radially outer edge of the conventional ring magnet 100. In addition, a portion of the magnetic flux from the magnetic field generating unit 80 passes from the region inside the cavity 71, through the outer surface of the cavity 71, and through the region radially outside the outer surface of the cavity 71. In this way, a portion of the magnetic flux from the magnetic field generating unit 80 is also formed in the region radially outside the outer surface of the cavity 71. The magnetic flux formed in the region radially outside the outer surface of the cavity 71 becomes leakage flux.

[0072] As shown in Figure 15, during the manufacturing of the ring magnet 50, the magnetic flux from the magnetic field generating unit 80 is attracted to the magnetic member 52, so the orientation of the magnetic powder in the bonded magnet 51 changes compared to the conventional ring magnet 100. Because the magnetic flux from the magnetic field generating unit 80 is attracted to the magnetic member 52, the leakage flux is reduced, and the magnetic flux density from the magnetic field generating unit 80 near the radially outer side of the ring magnet 50 increases. As a result, the orientation rate near the radially outer side of the ring magnet 50 becomes higher than that of the conventional ring magnet 100.

[0073] In this embodiment, orientation means that the easy magnetization axis of the magnetic powder contained in the bonded magnet material 51a is aligned in a predetermined direction. The orientation ratio is defined by the following equation (1) as the average value of the orientation component of each magnetic powder with respect to the predetermined direction. In this embodiment, the predetermined direction is the direction along the magnetic flux of the magnetic field generating unit 80.

[0074]

number

[0075] X is the orientation factor. N is the total number of magnetic particles contained in any given region. θ is the angle between a given direction and the easy magnetization axis of each magnetic particle. Any given region is defined, for example, by the observation range of a scanning electron microscope (SEM).

[0076] <Effects of the Embodiment> The effects of this embodiment will now be explained. (1-1) The method for manufacturing the ring magnet 50 includes a molding step. In the molding step, the ring magnet 50 is molded in a mold 60 by injecting bonded magnet material 51a into a cavity 71. The mold 60 comprises a mold body 70 and a magnetic field generating unit 80. The mold body 70 has a cylindrical cavity 71. The magnetic field generating unit 80 is positioned on the inner or outer circumferential surface side of the cavity 71 in the radial direction A3 and generates a magnetic field within the cavity 71. The bonded magnet material 51a contains magnetic powder with magnetic anisotropy. The magnetic field generating unit 80 has magnetic poles arranged in the circumferential direction A2 of the cavity 71. In the molding step, the bonded magnet material 51a is injected with a magnetic member 52 positioned in the cavity 71. The magnetic member 52 contains a soft magnetic material.

[0077] With this configuration, during the molding process, the magnetic flux from the magnetic field generating unit 80 is attracted to the magnetic member 52, thereby increasing the magnetic flux passing through the bonded magnet material 51a. In this way, the magnetic flux density near the magnetic member 52 can be increased, so the easy magnetization axis of the magnetic powder in the bonded magnet material 51a is more likely to align with the magnetic flux from the magnetic field generating unit 80 near the magnetic member 52. Therefore, the magnetic force of the ring magnet 50 can be increased.

[0078] (1-2) The method for manufacturing the ring magnet 50 includes a placement step. In the placement step, the magnetic member 52 is placed in the cavity 71. After the placement step, a molding step is performed in the method for manufacturing the ring magnet 50.

[0079] This configuration allows for the molding of a ring magnet 50 in which the bonded magnet 51 and the magnetic member 52 are integrally molded.

[0080] (1-3) The mold body 70 is provided with a mounting portion 72. A magnetic member 52 can be detachably attached to the mounting portion 72.

[0081] With this configuration, since the magnetic member 52 is attached to the mounting portion 72 of the mold body 70, it is possible to suppress the movement of the magnetic member 52 when the bonded magnet material 51a is injected during the molding process.

[0082] (1-4) The magnetic member 52 is positioned such that its longitudinal direction is aligned with the cylindrical axis direction A1 of the cavity 71.

[0083] In this configuration, the magnetic member 52 is positioned such that its longitudinal direction aligns with the cylindrical axis direction A1 of the cavity 71. Therefore, the magnetic member 52 can increase the magnetic flux passing through the bonded magnet material 51a along the cylindrical axis direction A1.

[0084] (1-5) The magnetic member 52 is positioned in the cavity 71 between adjacent magnetic poles in the circumferential direction A2.

[0085] With this configuration, the magnetic member 52 is positioned between adjacent magnetic poles in the circumferential direction A2, so that the magnetic flux between adjacent magnetic poles on either side of the magnetic member 52 can be attracted towards the vicinity of the magnetic member 52.

[0086] (1-6) The rotor 40 is equipped with a cylindrical ring magnet 50. The ring magnet 50 is a bonded magnet 51. The bonded magnet 51 contains magnetically anisotropic magnetic powder. The bonded magnet 51 is integrally molded with a magnetic member 52. The magnetic member 52 contains a soft magnetic material.

[0087] In this configuration, the magnetic flux passing through the ring magnet 50 is attracted to the magnetic member 52. As a result, the magnetic flux density near the magnetic member 52 in the ring magnet 50 can be increased compared to a ring magnet that does not include the magnetic member 52. Therefore, the magnetic force of the ring magnet 50 can be increased.

[0088] (1-7) In the ring magnet 50, the magnetic member 52 is positioned such that its longitudinal direction aligns with the cylindrical axis direction A1 of the ring magnet 50.

[0089] In this configuration, the magnetic member 52 is positioned such that its longitudinal direction aligns with the cylindrical axis direction A1 of the ring magnet 50. Therefore, the magnetic member 52 can increase the magnetic flux density of the ring magnet 50 near the magnetic member 52 along the cylindrical axis direction A1.

[0090] (1-8) The magnetic member 52 is positioned between adjacent magnetic poles in the circumferential direction A2 of the ring magnet 50.

[0091] In this configuration, the magnetic member 52 is positioned between adjacent magnetic poles in the circumferential direction A2 of the ring magnet 50. Therefore, the magnetic flux between adjacent magnetic poles with the magnetic member 52 in between can be attracted to the vicinity of the magnetic member 52.

[0092] (1-9) The motor 20 comprises a rotor 40 and a stator 30.

[0093] With this configuration, the magnetic force of the ring magnet 50 of the rotor 40 is improved, which in turn improves the rotational characteristics of the motor 20, such as rotational torque and rotational accuracy.

[0094] (1-10) The blower 1 comprises a motor 20 and a blower device 10. The blower device 10 is driven by the motor 20.

[0095] With this configuration, the blower 10 is driven by the motor 20, which has improved rotational characteristics, thus providing the blower 10 with an appropriate rotational force.

[0096] <Second Embodiment> Referring to Figures 17 to 21, the manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 according to the second embodiment will be described. Components in this embodiment that are common to the first embodiment are denoted by the same reference numerals as in the first embodiment, and redundant explanations are omitted.

[0097] In the ring magnet 50 of the first embodiment, the bonded magnet 51 and the magnetic member 52 are integrally molded, but as shown in Figure 17, the ring magnet 50 of this embodiment does not have a magnetic member 52. In the manufacturing method of the ring magnet 50 of the first embodiment, the magnetic member 52 is attached to the mounting portion 72, but in the manufacturing method of the ring magnet 50 of this embodiment, the magnetic member 52 is fixed to the mold body 70 of the molding die 60.

[0098] <Ring Magnet> As shown in Figure 18, a recess 56 is formed in the ring magnet 50. The recess 56 is the shape of the magnetic member 52 (see Figure 20). Since the magnetic member 52 in this embodiment is fixed to the mold body 70, the bonded magnet 51 constituting the ring magnet 50 hardens in the cavity 71 with the recess 56, which is the shape of the magnetic member 52, formed therein. The recess 56 is provided so that the longitudinal direction of the magnetic member 52 is aligned with the cylindrical axis direction A1 of the cavity 71. As shown in Figure 17, in the ring magnet 50 of this embodiment, the recess 56 is not formed on the first end face 53. In one example, when the ring magnet 50 is assembled into the rotor 40, the recess 56 remains an empty space.

[0099] A component other than the magnetic member 52 may be placed in the recess 56 after the removal process. A soft magnetic material may be placed in the recess 56. By placing a soft magnetic material in the recess 56, the soft magnetic material acts as a yoke. A part of the magnet holding portion 41 of the rotor 40 may be provided in the recess 56. This strongly suppresses the rotation of the rotor 40 relative to the magnet holding portion 41. A resin component such as rubber, which has a lower elastic modulus than the elastic modulus of the bonded magnet 51, may be provided in the recess 56. The resin component can suppress the effects of noise, vibration, etc. associated with the rotation of the rotor 40.

[0100] <How to manufacture a ring magnet> Figures 19 and 20 show the mold 60 of this embodiment. The magnetic member 52 is fixed to the mold body 70. The magnetic member 52 is fixed to the bottom surface 71a or side surface 71b within the cavity 71. The magnetic member 52 is fixed by methods such as bonding, welding, press-fitting, screwing, etc.

[0101] As shown in Figure 19, the magnetic member 52 is fixed between the magnetic poles of adjacent magnetic field generating units 80 in the circumferential direction A2. A magnetic member 52 similar to the magnetic member 52 of the first embodiment may also be fixed to the mold body 70.

[0102] In the manufacturing method of the ring magnet 50 of this embodiment, the arrangement step is omitted because the magnetic member 52 is fixed in the cavity 71 in advance. In the molding step of this embodiment, bond magnet material 51a is injected with the magnetic member 52 fixed in the mold body 70. Then, in the removal step, the ring magnet 50 is removed from the molding die 60. Because the magnetic member 52 is fixed in the mold body 70, when the ring magnet 50 is removed from the cavity 71 in the removal step, only the bond magnet 51 is removed from the cavity 71. After the removal step, the ring magnet 50 is magnetized in the magnetization step.

[0103] <Operation of the Embodiment> As shown in Figure 21, during the manufacturing of the ring magnet 50, the magnetic flux from the magnetic field generating unit 80 is attracted to the magnetic member 52 in the cavity 71, similar to the first embodiment. As a result, the orientation of the magnetic powder of the bonded magnet 51 around the recess 56 is directed towards the recess 56.

[0104] <Effects of the Embodiment> The effects of this embodiment will now be explained. (2-1) The magnetic member 52 is fixed to the mold body 70. In the molding process, the bonded magnet material 51a is injected with the magnetic member 52 fixed to the mold body 70.

[0105] With this configuration, since the magnetic member 52 is fixed to the mold body 70, the magnetic member 52 does not move when the bonded magnet material 51a is injected during the molding process. Therefore, the ring magnet 50 can be manufactured with high precision.

[0106] (2-2) A recess 56 is formed in the ring magnet 50. The recess 56 is the shape of the magnetic member 52.

[0107] With this configuration, a recess 56 in the shape of the magnetic member 52 can be formed in the bonded magnet 51.

[0108] <Third Embodiment> Referring to Figures 22 to 36, the manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 according to the third embodiment will be described. Components in this embodiment that are common with the first embodiment are denoted by the same reference numerals as in the first embodiment, and redundant explanations are omitted.

[0109] <Ring Magnet> As shown in Figure 22, the arrangement of the magnetic member 52 in the ring magnet 50 in this embodiment differs from the arrangement of the magnetic member 52 in the ring magnet 50 of the first embodiment. In this embodiment, the magnetic member 52 is arranged at the end of the ring magnet 50 in the cylindrical axis direction A1. The magnetic member 52 in this embodiment is formed in an annular shape. The magnetic member 52 is arranged at the end of the ring magnet 50 in the cylindrical axis direction A1. For example, the magnetic member 52 is arranged on the second end face 54. The magnetic member 52 may also be arranged on the first end face 53.

[0110] Figure 23 shows the second end face 54 of the ring magnet 50. As shown in Figures 23 and 24, the radially inner surface of the magnetic member 52 and the inner circumferential surface of the ring magnet 50 do not overlap. The radially outer surface of the magnetic member 52 and the outer circumferential surface of the ring magnet 50 do not overlap. The first length L1 between the radially inner surface of the magnetic member 52 and the inner circumferential surface of the ring magnet 50 in radial A3 is equal to the second length L2 between the radially outer surface of the magnetic member 52 and the outer circumferential surface of the ring magnet 50 in radial A3. The combined length of the first length L1 and the second length L2 is less than half the length of the ring magnet 50 in radial A3.

[0111] As shown in Figures 25 and 26, in this embodiment, during the placement process, the magnetic member 52 is positioned in the cavity 71 at the end of the cavity 71 in the direction of the cylindrical axis A1. In this embodiment, the magnetic member 52 is positioned on the bottom surface 71a of the cavity 71. As shown in Figure 27, with the magnetic member 52 positioned on the bottom surface 71a of the cavity 71, the movable part 90 is positioned on the mold body 70.

[0112] As shown in Figure 28, during the molding process, the bonded magnet material 51a is injected with the magnetic member 52 positioned on the bottom surface 71a of the cavity 71. As shown in Figure 29, the bonded magnet 51 is formed as the bonded magnet material 51a hardens.

[0113] As shown in Figure 30, after the bonded magnet material 51a has hardened, the movable part 90 is removed from the mold body 70. As shown in Figure 31, the ring magnet 50 is removed from the cavity 71.

[0114] <Operation of the Embodiment> The operation of this embodiment will now be explained. Figure 35 is a cross-sectional view of the conventional ring magnet 100 along the line D35-D35 in Figure 16. Figure 36 is an inner circumference view of the conventional ring magnet 100 as seen from arrow V36 in Figure 16. The white arrows in the figures indicate the direction of the easy magnetization axis of the magnetic powder of the bonded magnet 51. The black circles in the figures indicate the easy magnetization axis of the magnetic powder of the bonded magnet 51 pointing from the back of the page to the front of the page. The cross marks in the figures indicate the easy magnetization axis of the magnetic powder of the bonded magnet 51 pointing from the front of the page to the back of the page. In Figures 33 to 36, the mold body 70 used during the manufacturing of the ring magnet 50 is shown by a dashed line.

[0115] As shown in Figures 35 and 36, in the conventional ring magnet 100, magnetic powder is difficult to orient near the end in the cylindrical axis direction A1. This is because the magnetic field generating unit 80 does not easily overlap with the cavity 71 of the mold body 70 in the radial direction A3.

[0116] Figure 32 is an enlarged view of the vicinity of adjacent magnetic poles in the ring magnet 50 of this embodiment. Figure 33 is a cross-sectional view of the ring magnet 50 along the line D33-D33 in Figure 32. Figure 33 is an inner circumference view of the ring magnet 50 as seen from arrow V34 in Figure 32.

[0117] In the ring magnet 50 of this embodiment, since the magnetic member 52 is placed on the bottom surface 71a of the cavity 71, the magnetic flux of the magnetic field generating unit 80 is attracted to the vicinity of the bottom surface 71a of the cavity 71. As a result, the magnetic flux density of the magnetic field generating unit 80 passing near the bottom surface 71a of the cavity 71 increases. Due to these magnetic fluxes, the bonded magnet material 51a near the bottom surface 71a of the cavity 71 becomes more susceptible to the influence of the magnetic flux of the magnetic field generating unit 80, and the magnetic powder of the bonded magnet 51 near the end of the ring magnet 50 in the cylindrical axis direction A1 is oriented by the magnetic flux of the magnetic field generating unit 80.

[0118] <Effects of the Embodiment> The effects of this embodiment will now be explained. (3-1) The magnetic member 52 is positioned in the cavity 71 at the end of the cavity 71 in the direction A1 of the cylindrical axis.

[0119] This configuration makes it possible to increase the magnetic flux density passing through the bonded magnet material 51a at the end of the cavity 71 in the direction A1 of the cylindrical axis.

[0120] (3-2) The magnetic member 52 is positioned at the end of the ring magnet 50 in the cylindrical axis direction A1.

[0121] This configuration makes it possible to increase the magnetic flux density at the end of the ring magnet 50 in the cylindrical axis direction A1.

[0122] <Variation> The manufacturing methods for the blower 1, motor 20, rotor 40, and ring magnet 50 of this disclosure may also be modified in ways other than those described above, such as those shown below, or in combination of at least two mutually non-inconsistent modifications.

[0123] [Modified version of the first embodiment] As shown in Figure 37, the magnetic member 52 may be exposed from the end face of the ring magnet 50. In the example in Figure 37, the magnetic member 52 is exposed at the first end face 53 of the ring magnet 50. The magnetic member 52 may also be exposed at the second end face 54 of the ring magnet 50.

[0124] As shown in Figures 38 and 39, in the ring magnet 50, two or more magnetic members 52 may be arranged between adjacent magnetic poles in the circumferential direction A2 of the ring magnet 50. In the example of Figure 38, a first magnetic member 52X and a second magnetic member 52Y are arranged between adjacent magnetic poles in the circumferential direction A2 of the ring magnet 50. Near the midpoint between adjacent magnetic poles, the first magnetic member 52X is positioned on the N pole side and the second magnetic member 52Y is positioned on the S pole side. The first magnetic member 52X is positioned along the radial direction A3 such that its radially outer side is tilted towards the N pole side. The second magnetic member 52Y is positioned along the radial direction A3 such that its radially outer side is tilted towards the S pole side. In this modified example, the magnetic members 52 are separated from both the outer and inner circumferential surfaces of the ring magnet 50. As shown in Figure 39, during the manufacturing of the ring magnet 50, the magnetic field of the magnetic field generating unit 80 is attracted to the first magnetic member 52X and the second magnetic member 52Y, which changes the orientation of the magnetic powder compared to the conventional ring magnet 100.

[0125] As shown in Figures 40 and 41, in the ring magnet 50, the magnetic member 52 may be positioned so as to overlap with the magnetic poles of the ring magnet 50 in the radial direction A3. In the example of Figure 40, the magnetic member 52 is positioned in the radially inner region of the ring magnet 50. In this modified example, the magnetic member 52 is arc-shaped when viewed from the cylindrical axis direction A1. The outer circumferential surface of the magnetic member 52 is separated from the outer circumferential surface of the ring magnet 50. In this modified example, the inner circumferential surface of the magnetic member 52 may overlap with the inner circumferential surface of the ring magnet 50 in the circumferential direction A2. When the ring magnet 50 is molded, by positioning the magnetic member 52 radially inward within the cavity 71, the magnetic flux of the magnetic field generating unit 80 can be attracted to the inside of the cavity 71. As a result, as shown in Figure 41, the orientation of the magnetic powder changes compared to the conventional ring magnet 100.

[0126] As shown in Figures 42 and 43, the magnetic member 52 may be positioned radially outward of the ring magnet 50 so as to overlap with the magnetic pole in the radial direction A3. In the example of Figure 42, the magnetic member 52 is positioned in the radially outward region of the ring magnet 50. In this modified example, the magnetic member 52 is arc-shaped when viewed from the cylindrical axis direction A1. The inner circumferential surface of the magnetic member 52 is separated from the inner circumferential surface of the ring magnet 50. In this modified example, the outer circumferential surface of the magnetic member 52 may overlap with the outer circumferential surface of the ring magnet 50 in the circumferential direction A2. When the ring magnet 50 is molded, by positioning the magnetic member 52 radially outward within the cavity 71, the magnetic flux of the magnetic field generating section 80 formed in the radially outward region outside the cavity 71 can be attracted to the magnetic member 52. As a result, as shown in Figure 43, the orientation of the magnetic powder changes compared to the conventional ring magnet 100.

[0127] As shown in Figure 44, the mounting structure between the magnetic member 52 and the mounting portion 72 is not limited to an engagement structure between the through hole 52a and the pole 72a. The mounting portion 72 may have, for example, a plate-shaped member 72b. The magnetic member 52 may have, for example, a slit 52b. The slit 52b is provided on at least one of the bottom surface 71a and the side surface 71b of the cavity 71. The magnetic member 52 is attached to the mounting portion 72 by inserting the plate-shaped member 72b of the mounting portion 72 through the slit 52b of the magnetic member 52.

[0128] As shown in Figure 45, the mounting portion 72 may have, for example, a mounting recess 72c. In this modified example, the mounting recess 72c is provided on the bottom surface 71a of the cavity 71. As shown in Figure 46, the mounting recess 72c is a recess in the cylindrical axis direction A1. As shown in Figure 47, the movement of the magnetic member 52 is suppressed during the molding process by fitting the end of the magnetic member 52 into the mounting recess 72c.

[0129] As shown in Figure 48, the mounting recess 72c may be provided on the side surface 71b of the cavity 71. In this modified example, the mounting recess 72c is a recess in the radial direction A3. The mounting recess 72c is provided, for example, on the radially inward side surface 71b. As shown in Figure 49, the mounting recess 72c in this modified example extends along the cylindrical axis direction A1. As shown in Figure 50, the movement of the magnetic member 52 during the molding process is suppressed by fitting the magnetic member 52 into the mounting recess 72c.

[0130] As shown in Figure 51, a first protrusion 72d and a second protrusion 72e may protrude from the side surface 71b of the cavity 71, and a mounting recess 72c may be provided between the first protrusion 72d and the second protrusion 72e.

[0131] [Modified version of the second embodiment] In the ring magnet 50 of the second embodiment, a recess 56 is not formed on the first end face 53 of the ring magnet 50, but as shown in Figure 52, a recess 56 may be formed on the end face of the ring magnet 50 in the cylindrical axis direction A1. In the example of Figure 53, a recess 56 is formed on the first end face 53 of the ring magnet 50. A recess 56 may also be formed on the second end face 54 of the ring magnet 50.

[0132] In the example shown in Figure 53, two magnetic members 52 are positioned in the cavity 71 between adjacent magnetic poles of the ring magnet 50 in the circumferential direction A2. The ring magnet 50 is provided with a first recess 56X and a second recess 56Y between adjacent magnetic poles in the circumferential direction A2. Near the midpoint between the adjacent magnetic poles, the first recess 56X is positioned on the N pole side, and the second recess 56Y is positioned on the S pole side.

[0133] In the example shown in Figure 54, a magnetic member 52 is positioned radially inward of the cavity 71 such that it overlaps with the magnetic poles of the ring magnet 50 in the radial direction A3. The ring magnet 50 has a recess 56 in the radially inward region of the bonded magnet 51 such that it overlaps with the magnetic poles of the ring magnet 50 in the radial direction A3 of the ring magnet 50.

[0134] In the example shown in Figure 55, a magnetic member 52 is positioned radially outward of the cavity 71 such that it overlaps with the magnetic poles of the ring magnet 50 in the radial direction A3. The ring magnet 50 has a recess 56 in the region radially outward of the bonded magnet 51 such that it overlaps with the magnetic poles of the ring magnet 50 in the radial direction A3 of the ring magnet 50.

[0135] [Modified version of the third embodiment] In the ring magnet 50 of the third embodiment, the first length L1 between the radially inner side of the magnetic member 52 and the inner circumferential surface of the ring magnet 50 in the radial direction A3 is equal to the second length L2 between the radially outer side of the magnetic member 52 and the outer circumferential surface of the ring magnet 50 in the radial direction A3. In the example of Figure 56, the first length L1 is greater than the second length L2.

[0136] In the example in Figure 57, the first length L1 is smaller than the second length L2.

[0137] In the third embodiment, the combined length of the first length L1 and the second length L2 is less than half the length of the ring magnet 50 in the radial direction A3, but as shown in the example in Figure 58, the combined length of the first length L1 and the second length L2 may be half or more the length of the ring magnet 50 in the radial direction A3.

[0138] As shown in Figure 59, the portion of the magnetic member 52 that overlaps with the magnetic poles of the ring magnet 50 in the radial direction A3 may be omitted. In the example in Figure 59, the portion of the magnetic member 52 that overlaps with the magnetic poles of the ring magnet 50 in the radial direction A3 is not provided. In this modified example as well, during the manufacturing of the ring magnet 50, the magnetic flux of the magnetic field generating portion 80 can be attracted to the vicinity of the bottom surface 71a of the cavity 71 near the midpoint between the magnetic poles of adjacent magnetic field generating portions 80 in the circumferential direction A2.

[0139] As shown in Figure 60, a first radial recess 58 may be formed in the magnetic member 52 in the portion that overlaps with the magnetic pole of the ring magnet 50 in the radial direction A3.

[0140] As shown in Figures 61 and 62, the magnetic member 52 may be placed on the first end face 53 in addition to the second end face 54 of the ring magnet 50. The magnetic member 52 placed on the first end face 53 is provided with a through hole 52a in the portion facing the gate 93 of the mold 60. The through hole 52a overlaps with the gate mark 55.

[0141] As shown in Figure 63, in the magnetic member 52 positioned on the first end face 53 of the ring magnet 50, the portion in the circumferential direction A2 that is in the same position as the magnetic pole of the ring magnet 50 may be omitted. A gate mark 55 is located in the portion of the magnetic member 52 that is omitted.

[0142] As shown in Figure 64, a second radial recess 59 may be formed in the magnetic member 52 positioned on the first end face 53 of the ring magnet 50, at the same location as the magnetic pole of the ring magnet 50 in the circumferential direction A2.

[0143] As shown in Figure 65, a retaining member 61 may be provided on the mold 60. The retaining member 61 holds the magnetic member 52 in the cavity 71. In this modified example, the retaining member 61 is provided on the movable part 90. The end of the retaining member 61 is located near the bottom surface 71a in the cavity 71 when the movable part 90 is attached to the mold body 70. As shown in Figure 66, the movable part 90 is placed on the mold body 70 during the placement process. The magnetic member 52 in the cavity 71 is sandwiched between the end of the retaining member 61 and the bottom surface 71a in the cavity 71. As shown in Figure 67, the outer circumferential surface of the ring magnet 50 in this modified example is provided with a circumferential recess 57 in the shape of the retaining member 61.

[0144] As shown in Figure 68, the retaining member 61 may be provided on the mold body 70. In this modified example, the retaining member 61 holds the magnetic member 52 which is positioned on the first end face 53 of the ring magnet 50. In the positioning process, the movable part 90 is positioned on the mold body 70. As shown in Figure 69, the magnetic member 52 in the cavity 71 is sandwiched between the end of the retaining member 61 and the movable part 90. As shown in Figure 70, the inner circumferential surface of the ring magnet 50 in this modified example is provided with a circumferential recess 57 in the shape of the retaining member 61. Note that Figure 70 shows the second end face 54 of the ring magnet 50.

[0145] [Modified examples common to all embodiments] The position of gate 93 may be changed as desired. Gate 93 may be positioned offset from the magnetic poles of the magnetic field generating unit 80 in the circumferential direction A2.

[0146] In the manufacturing method of the ring magnet 50, the magnetization step may be omitted. In this modified example, the ring magnet 50 may be magnetized during the molding step.

[0147] The shape of the magnetic member 52 may be changed as desired. Examples of the shape of the magnetic member 52 include a cylinder and a rectangular prism. The corners of the magnetic member 52 may be chamfered. The surface of the magnetic member 52 may be provided with irregularities or grooves.

[0148] The motor 20 may be an inner rotor. In this modified example, two or more magnetic poles are arranged on the outer surface of the ring magnet 50. In this modified example, the magnetic field generating unit 80 is located on the outer surface side of the cavity 71 in the radial direction A3.

[0149] The motor 20 may be used as a motor to drive a blower installed in the outdoor unit of an air conditioner.

[0150] The blower 10 may have an impeller other than the cross-flow fan 11. Examples of impellers include the cross-flow fan, propeller fan, turbo fan, and sirocco fan of each embodiment.

[0151] The refrigeration system may include a motor 20. Examples of refrigeration systems include air conditioners, water heaters, chiller units, and cooling devices for cooling the air inside a storage area, as in each embodiment. The air inside a storage area refers to the air inside a refrigerator, freezer, display case, container, etc. These refrigeration systems include a compressor. The motor 20 is used as a motor for the compressor of the refrigeration system. With this configuration, the refrigeration system can be stably driven by the motor 20, which has improved rotational characteristics. [Explanation of Symbols]

[0152] 1...Blower, 10...Blower device, 20...Motor, 30...Stator, 40...Rotor, 50...Ring magnet, 51...Bonded magnet, 51a...Bonded magnet material, 52...Magnetic member, 56...Recess, 60...Mold, 70...Mold body, 71...Cavity, 72...Mounting part, 80...Magnetic field generating part.

Claims

1. A method for manufacturing a ring magnet (50), A mold (60) comprising a mold body (70) having a cylindrical cavity (71), and a magnetic field generating unit (80) disposed on the inner or outer circumferential side of the cavity (71) in the radial direction (A3) of the cavity (71) and generating a magnetic field within the cavity (71), The process includes a molding step of forming the ring magnet (50) by injecting a bonded magnet material (51a) containing magnetically anisotropic magnetic powder into the cavity (71), The magnetic field generating unit (80) has magnetic poles arranged in the circumferential direction (A2) of the cavity (71), In the molding process, the bonded magnet material (51a) is injected with the magnetic member (52) containing the soft magnetic material placed in the cavity (71). A method for manufacturing ring magnets.

2. The process includes placing the magnetic member (52) in the cavity (71), After the arrangement step, the molding step is performed. A method for manufacturing a ring magnet according to claim 1.

3. The mold body (70) is provided with a mounting portion (72) to which the magnetic member (52) can be detachably attached. A method for manufacturing a ring magnet according to claim 2.

4. The magnetic member (52) is fixed to the mold body (70), In the molding process, the bonded magnet material (51a) is injected while the magnetic member (52) is fixed to the mold body (70). A method for manufacturing a ring magnet according to claim 1.

5. The ring magnet (50) has a recess (56) formed in the shape of the magnetic member (52). A method for manufacturing a ring magnet according to claim 4.

6. The magnetic member (52) is positioned such that its longitudinal direction is aligned with the cylindrical axis direction (A1) of the cavity (71). A method for manufacturing a ring magnet according to claim 1.

7. The magnetic member (52) is positioned in the cavity (71) between adjacent magnetic poles in the circumferential direction (A2). A method for manufacturing a ring magnet according to claim 1.

8. The magnetic member (52) is positioned in the cavity (71) at the end of the cavity (71) in the direction of the cylindrical axis (A1). A method for manufacturing a ring magnet according to claim 1.

9. The rotor (40) of the motor (20), The rotor (40) is equipped with a cylindrical ring magnet (50), The ring magnet (50) is a bonded magnet (51) containing magnetic anisotropic magnetic powder, in which a magnetic member (52) containing a soft magnetic material is integrally molded. Rotor.

10. The magnetic member (52) is positioned such that, in the ring magnet (50), the longitudinal direction of the magnetic member (52) is aligned with the cylindrical axis direction (A1) of the ring magnet (50). The rotor according to claim 9.

11. The magnetic member (52) is positioned in the ring magnet (50) between adjacent magnetic poles in the circumferential direction (A2) of the ring magnet (50). The rotor according to claim 9.

12. The magnetic member (52) is positioned at the end of the ring magnet (50) in the cylindrical axis direction (A1) of the ring magnet (50). The rotor according to claim 9.

13. A rotor (40) and a stator (30) as described in any one of claims 9 to 12, Motor.

14. The invention comprises a motor (20) as described in claim 13, and a blower (10) driven by the motor (20), Blower.

15. The motor (20) according to claim 13 is provided, Refrigeration equipment.

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