Magnetic core, magnetic core with coil, rotary electric machine and brushless motor

Abstract

A magnetic core, a magnetic core with a coil, a rotary electric machine and a brushless motor are provided. The magnetic core is used in a rotary electric machine, and is provided with a tooth portion having a shape extending in a first direction. The tooth portion includes a portion to be wound around which a coil is wound, and the portion to be wound has: a first lobe through which the coil passes during winding of the coil; a first contact surface that is a first contact surface on which the coil comes into contact before passing through the first lobe, and that has a curved shape protruding in the second direction when viewed in the first direction; a first non-contact surface on which the coil is not in contact, the first non-contact surface having a first lobe at a boundary between the first non-contact surface and the first contact surface; and a second contact surface that is a second contact surface on which the coil comes into contact after passing through the first lobe, and that has a curved shape protruding in a third direction different from the second direction when viewed in the first direction.

Description

Technical Field

[0001] The invention relates to a magnetic core, a magnetic core with a coil, a rotating electrical machine and a brushless motor. Background Art

[0002] As an invention related to the existing magnetic core, for example, there is a known magnetic core described in Patent Document 1. The magnetic core described in Patent Document 1 has a tooth portion. A coil is wound on the tooth portion. An insulating film is formed on the surface of the coil. When viewed in the direction in which the tooth portion extends, the tooth portion has a quadrilateral shape. When the coil is wound on the tooth portion, the insulating film formed on the surface of the coil contacts the four vertices of the tooth portion.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2006-158176

[0004] In the magnetic core described in Patent Document 1, the insulating film formed on the surface of the coil contacts the four vertices of the teeth, so stress is concentrated on the contact portions of the insulating film with the vertices, and the insulating film may be damaged. As a result, the electrical insulation between the magnetic core and the coil may be reduced.

[0005] Therefore, an object of the present invention is to provide a magnetic core, a magnetic core with a coil, a rotating electric machine, and a brushless motor capable of suppressing a decrease in electrical insulation between the magnetic core and the coil due to damage to an insulating film formed on the surface of the coil.

[0006] The inventor of the present application has investigated the situation where the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil. As a result, it has been noted that in the magnetic core described in Patent Document 1, the shape of the tooth portion can be made elliptical or circular when observed in the direction in which the tooth portion extends. By making the shape of the tooth portion elliptical or circular when observed in the direction in which the tooth portion extends, the tooth portion does not have a vertex. This is because, thereby, the bending angle of each part of the coil can be made greater than 90 degrees, which can alleviate the situation in which local stress concentration is formed in the insulating film formed on the surface of the coil.

[0007] Next, the inventors of the present application studied a method for manufacturing a tooth portion having an elliptical or circular shape when viewed in the direction in which the tooth portion extends. In the case where a tooth portion having an elliptical or circular shape when viewed in the direction in which the tooth portion extends is manufactured by the manufacturing method described in Patent Document 1, it is necessary to make the shape of the lower end surface of the punch 201 described in Patent Document 1 (hereinafter referred to as the upper punch) into a semi-elliptical or semi-circular shape that is curved protruding upward, and to make the shape of the upper end surface of the punch 202 described in Patent Document 1 (hereinafter referred to as the lower punch) into a semi-elliptical or semi-circular shape that is curved protruding downward.

[0008] When the shape of the tooth portion is made elliptical or circular when observed in the direction in which the tooth portion extends, it is ideal that the lower end surface of the upper punch is bent in a semi-elliptical or semi-circular shape over the entire area without leaving any flat portions at both ends, and the upper end surface of the lower punch is bent in a semi-elliptical or semi-circular shape over the entire area without leaving any flat portions at both ends.

[0009] However, in reality, due to problems with machining accuracy and mold strength, the lower end face of the upper punch and the upper end face of the lower punch have flat portions remaining at both ends. Therefore, when the tooth portion is formed by the upper punch and the lower punch, a convex portion formed by sandwiching the upper and lower flat portions is formed on the tooth portion. Moreover, when a coil is wound around the tooth portion, such a convex portion may damage the insulating film of the coil, thereby reducing the electrical insulation between the tooth portion and the coil. Summary of the invention

[0010] Based on the above research, the inventors of the present application have studied a magnetic core that can suppress a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil. As a result, the inventors of the present application have conceived the following invention.

[0011] A magnetic core involved in one embodiment of the present invention is a magnetic core used in a rotating electrical machine, comprising a tooth portion, the tooth portion having a shape extending in a first direction, the tooth portion including a wound portion on which a coil is wound, the wound portion having: a first convex angle, which is for the coil to pass through during the process of winding the coil; a first contact surface, which is the first contact surface for the coil to contact before passing through the first convex angle, and has a shape protrudingly bent in a second direction when viewed in the first direction; a first non-contact surface, which is the first non-contact surface that the coil does not contact, and the boundary between the first non-contact surface and the first contact surface is the first convex angle; and a second contact surface, which is the second contact surface for the coil to contact after passing through the first convex angle, and has a shape protrudingly bent in a third direction different from the second direction when viewed in the first direction.

[0012] A magnetic core according to one embodiment of the present invention is a magnetic core used in a rotating electrical machine, and comprises a tooth portion, wherein the tooth portion has a shape extending in a first direction, the tooth portion includes a wound portion on which a coil is wound, and the wound portion has: a first convex angle, which allows the coil to pass through during the process of winding the coil; a first contact surface, which is a first contact surface for the coil to contact before passing through the first convex angle, and has a shape protrudingly curved in a second direction when viewed in the first direction; a second contact surface, which is a first non-contact surface for the coil to contact after passing through the first convex angle; and a first non-contact surface, which is a first non-contact surface provided between the first contact surface and the second contact surface and with which the coil does not contact, and the first non-contact surface is The boundary between the contact surface and the above-mentioned second contact surface is the above-mentioned first convex angle; the second convex angle, which is a convex angle different from the above-mentioned first convex angle and is provided for the above-mentioned coil to pass after passing through the above-mentioned second contact surface; and the third contact surface, which is the third contact surface for the above-mentioned coil to contact after passing through the above-mentioned second convex angle, and when observed in the above-mentioned first direction, has a shape that is protrudingly bent in a third direction different from the above-mentioned second direction; and the second non-contact surface, which is a non-contact surface different from the above-mentioned first non-contact surface, and is a second non-contact surface arranged between the above-mentioned second contact surface and the above-mentioned third contact surface and not contacted by the above-mentioned coil, and the boundary between the second non-contact surface and the above-mentioned second contact surface is the above-mentioned second convex angle.

[0013] According to the present invention, it is possible to provide a magnetic core, a magnetic core with a coil, a rotating electric machine, and a brushless motor capable of suppressing a decrease in electrical insulation between the magnetic core and the coil due to damage to an insulating film formed on the surface of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of the magnetic core 1 according to the first embodiment of the present invention.

[0015] Figure 2 This is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1.

[0016] Figure 3 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 .

[0017] Figure 4 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 .

[0018] Figure 5 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 .

[0019] Figure 6This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 .

[0020] Figure 7 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 .

[0021] Figure 8 1 is a perspective view of the appearance of a brushless motor 100 using the magnetic core 1 .

[0022] Fig. 9 It is an exploded perspective schematic diagram of a brushless motor 100 using the magnetic core 1 .

[0023] Fig.10 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 6 according to the comparative example, as viewed from the first direction DIR1.

[0024] Fig.11 This is a cross-sectional view of the magnetic core 1a as viewed from the first direction DIR1.

[0025] Fig.12 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0026] Fig.13 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0027] Fig.14 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0028] Fig.15 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0029] Fig.16 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0030] Fig.17 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0031] Fig.18 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0032] Fig.19 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0033] Fig. 20 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 .

[0034] Fig.21 This is a cross-sectional view of the magnetic core 1b as viewed from the first direction DIR1. DETAILED DESCRIPTION

[0035] [First embodiment]

[0036] (Structure of magnetic core 1)

[0037] Figure 1 1 is a perspective view of a magnetic core 1 according to a first embodiment of the present invention. Figure 1 As shown, the magnetic core 1 includes a core back 2 and a tooth portion 3. The tooth portion 3 has a shape extending from the core back 2 in the first direction DIR1. In the present embodiment, the tooth portion 3 includes: a tooth body portion 31 extending from the core back 2 in the first direction DIR1; and a tooth terminal portion formed at the terminal of the tooth body portion 31 in the first direction DIR1. In addition, the tooth body portion 31 is a portion wound with the coil 13, and corresponds to the "wound portion" of the present invention. Such a magnetic core 1 of the present embodiment is used in the following brushless motor 100 (an example of the "rotating electrical machinery" of the present invention; refer to Figure 8 and Fig. 9 ). When the core 1 is assembled in the brushless motor 100, the first direction DIR1 is oriented in the opposite direction of the radial direction centered on the rotation axis of the brushless motor 100. This will be described in detail below.

[0038] Figure 2 This is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1. Figure 3 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 . Figure 4 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 . Figure 5 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 . Figure 6 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 . Figure 7 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 as viewed from the first direction DIR1 .

[0039] The magnetic core 1 is a soft magnetic body. The soft magnetic body is magnetized when a magnetic field is applied from the outside. Thereafter, when the application of the magnetic field is stopped, the soft magnetic body loses its magnetization. The material of such a soft magnetic body is, for example, iron.

[0040] The magnetic core 1 is a molded body formed of soft magnetic powder. That is, the core back 2 and the tooth portion 3 are each a molded body formed of soft magnetic powder. The material of the soft magnetic powder includes, for example, iron and a binder. The binder is, for example, a resin. The soft magnetic powder is, for example, a material obtained by mixing iron powder and an epoxy resin as an example of a binder. Such a magnetic core 1 is made, for example, by press molding. In addition, the outer surface of the magnetic core 1 that contacts other components when the magnetic core 1 is assembled in the brushless motor 100 is subjected to insulation treatment.

[0041] like Figure 1 As shown, the core back 2 has a first main surface S1 and a second main surface S2 arranged in the first direction DIR1. The second main surface S2 is located closer to the first main surface S1 in the first direction DIR1. In addition, when viewed in the first direction DIR1, the first main surface S1 and the second main surface S2 each have a rectangular shape.

[0042] like Figure 1 As shown, the tooth body portion 31 extends from the second main surface S2 of the core back 2 in the first direction DIR1.

[0043] like Figure 2 As shown, the tooth body portion 31 has a first contact surface CS1, a first convex angle A1, a first non-contact surface NCS1, a second contact surface CS2, a second convex angle A2, and a second non-contact surface NCS2.

[0044] like Figure 2 As shown, the first contact surface CS1 has a shape that is protrudingly bent toward the second direction DIR2. In more detail, when observed in the first direction DIR1, the first contact surface CS1 has a semi-elliptical shape. In addition, the semicircular shape is included in the semi-elliptical shape. In the present embodiment, when observed in the first direction DIR1, the first contact surface CS1 has a semicircular shape. Therefore, when observed in the first direction DIR1, the first contact surface CS1 is a part of a circle with a radius RCS1 centered on the center OCS1. In addition, the second direction DIR2 is orthogonal to the first direction DIR1. In addition, the second direction DIR2 is a direction along the rotation axis of the brushless motor 100 when the magnetic core 1 is assembled in the brushless motor 100.

[0045] like Figure 2As shown, the first non-contact surface NCS1 is a plane facing the third direction DIR3. That is, the normal direction of the first non-contact surface NCS1 is the third direction DIR3. In addition, the third direction DIR3 is a direction orthogonal to the first direction DIR1 and is a direction different from the second direction DIR2. The third direction DIR3 is the opposite direction of the second direction DIR2.

[0046] In this embodiment, if Figure 2 As shown, when observed in the first direction DIR1, the first convex angle A1 is the angle formed by the tangent lines of the first contact surface CS1 and the first non-contact surface NCS1 at the first convex angle A1. In more detail, when observed in the first direction DIR1, the first convex angle A1 protrudes in the radial direction centered on the central axis CA31 of the tooth body portion 31. Therefore, the boundary between the first non-contact surface NCS1 and the first contact surface CS1 is the first convex angle A1. In addition, the first convex angle A1 is located on the first contact surface CS1. In addition, the central axis CA31 of the tooth body portion 31 is a line connecting the centers of the cross sections of the tooth body portion 31 that are perpendicular to the first direction DIR1. In the present embodiment, the first convex angle A1 is 90 degrees.

[0047] like Figure 2 As shown, the second contact surface CS2 is located closer to the third direction DIR3 than the first contact surface CS1. In addition, when observed in the first direction DIR1, the second contact surface CS2 has a shape that is curved protrudingly toward the third direction DIR3. In more detail, when observed in the first direction DIR1, the second contact surface CS2 has a semi-elliptical shape. In addition, the semicircular shape is included in the semi-elliptical shape. In the present embodiment, when observed in the first direction DIR1, the second contact surface CS2 has a semicircular shape. Therefore, when observed in the first direction DIR1, the second contact surface CS2 is a part of a circle with a radius RCS2 centered on the center OCS2. The radius RCS2 of the second contact surface CS2 is equal to the radius RCS1 of the first contact surface CS1. In addition, the position of the center OCS2 in the fourth direction DIR4 orthogonal to the first direction DIR1 and the second direction DIR2 is different from the position of the center OCS1 in the fourth direction DIR4.

[0048] like Figure 2 As shown, the second non-contact surface NCS2 is a plane facing the second direction DIR2. That is, the normal direction of the second non-contact surface NCS2 is the second direction DIR2.

[0049] like Figure 2As shown, the second convex angle A2 is a convex angle different from the first convex angle A1. In more detail, in the present embodiment, when observed in the first direction DIR1, the second convex angle A2 is the angle formed by the tangent of the second contact surface CS2 and the second non-contact surface NCS2 at the second convex angle A2. In more detail, when observed in the first direction DIR1, the second convex angle A2 protrudes in the radial direction centered on the central axis CA31 of the tooth body portion 31. Therefore, the boundary between the second non-contact surface NCS2 and the second contact surface CS2 is the second convex angle A2. In addition, the second convex angle A2 is located on the second contact surface CS2. In the present embodiment, the second convex angle A2 is 90 degrees.

[0050] like Figure 2 As shown, when viewed in the first direction DIR1, the tooth body portion 31 has a point-symmetrical shape.

[0051] like Figure 3 to Figure 7 As shown, the coil 13 is wound around the tooth body 31. The coil 13 is made of a conductive material such as copper. In addition, the coil 13 has a structure in which the surface of the copper wire is covered with an insulating film. The structure in which the surface of the copper wire is covered with an insulating film makes the coil 13 electrically insulated from the magnetic core 1. The coil 13 generates a magnetic field by flowing a current in the coil 13 when the coil 13 is assembled in the brushless motor 100.

[0052] Next, the process of winding the coil 13 on the tooth body 31 will be described. Figure 3 As shown, the coil 13 contacts the first contact surface CS1. That is, the coil 13 contacts the first contact surface CS1 before the coil 13 passes the first convex corner A1.

[0053] Next, if Figure 4 As shown, the coil 13 passes through the first convex corner A1. That is, the coil 13 is in contact with the first convex corner A1.

[0054] Next, if Figure 5 As shown, the coil 13 contacts the second contact surface CS2. That is, the coil 13 contacts the second contact surface CS2 after passing through the first convex angle A1. In addition, the coil 13 does not contact the first non-contact surface NCS1. In addition, the bending angle θ1 of the coil 13 between the first convex angle A1 and the second contact surface CS2 is greater than 90 degrees.

[0055] Next, if Figure 6 As shown, the coil 13 passes through the second convex corner A2. That is, the coil 13 passes through the second convex corner A2 after passing through the second contact surface CS2. In addition, the coil 13 contacts the second convex corner A2.

[0056] Next, if Figure 7As shown, the coil 13 contacts the first contact surface CS1. That is, the coil 13 contacts the first contact surface CS1 again after passing through the second convex angle A2. In addition, the coil 13 does not contact the second non-contact surface NCS2. In addition, the bending angle θ2 of the coil 13 between the first contact surface CS1 and the second convex angle A2 is greater than 90 degrees.

[0057] By repeating the above process, the coil 13 is wound around the tooth body portion 31 .

[0058] The tooth tip portion 32 has a third main surface S3 and a fourth main surface S4 arranged in the first direction DIR1. The fourth main surface S4 is located closer to the third main surface S3 in the first direction DIR1. When viewed in the first direction DIR1, the third main surface S3 and the fourth main surface S4 each have a rectangular shape.

[0059] like Figure 1 As shown, the outer edge O2 of the core back 2 viewed in the first direction DIR1 surrounds the outer edge O31 of the tooth body 31 viewed in the first direction DIR1. In addition, the outer edge O32 of the tooth tip 32 viewed in the first direction DIR1 surrounds the outer edge O31 of the tooth body 31 viewed in the first direction DIR1.

[0060] (Structure of Brushless Motor 100)

[0061] Hereinafter, the structure of the brushless motor 100 according to the first embodiment of the present invention will be described with reference to the drawings. Figure 8 1 is a perspective view of the appearance of a brushless motor 100 using the magnetic core 1 . Fig. 9 1 is an exploded perspective view schematically showing a brushless motor 100 using the magnetic core 1. Fig. 9 In the drawings, only representative magnetic cores 1 , coils 13 , and magnetic cores 14 with coils among the plurality of magnetic cores 1 , the plurality of coils 13 , and the plurality of magnetic cores 14 with coils are denoted by reference numerals.

[0062] like Fig. 9 As shown, the brushless motor 100 includes a rotor 20 and a stator assembly 10. Fig. 9 As shown, when viewed in the second direction DIR2, the stator assembly 10 is disposed around the rotor 20. That is, the brushless motor 100 is an inner rotor type.

[0063] like Fig. 9 As shown, the rotor 20 includes a shaft body 21 and a rotor member 22. The shaft body 21 has a shape extending in the second direction DIR2. In more detail, the shaft body 21 is cylindrical. The rotor member 22 is cylindrical. The central axis of each of the shaft body 21 and the rotor member 22 is the Z axis. That is, the rotation axis of the brushless motor 100 is the Z axis. Therefore, the second direction DIR2 is a direction along the Z axis.

[0064] like Fig. 9 As shown, the rotor component 22 includes a soft magnetic body 23 and a hard magnetic body 24. The rotor component 22 is mounted on the outer peripheral surface of the shaft body 21 in the radial direction centered on the Z axis. More specifically, the soft magnetic body 23 is mounted on the outer peripheral surface of the shaft body 21 in the radial direction centered on the Z axis. The hard magnetic body 24 is mounted on the outer peripheral surface of the soft magnetic body 23 in the radial direction centered on the Z axis.

[0065] The soft magnetic body 23 is a soft magnetic body. In addition, the hard magnetic body 24 is a hard magnetic body. The hard magnetic body is magnetized when a magnetic field is applied from the outside. Thereafter, even if the application of the magnetic field is stopped, the hard magnetic body does not lose its magnetization. The material of such a hard magnetic body is a magnet.

[0066] like Fig. 9 As shown, the stator assembly 10 includes a bearing 11, a housing 12, and a plurality of cores 14 with coils. Each of the plurality of cores 14 with coils includes a core 1 and a coil 13. That is, the brushless motor 100 includes a core 1.

[0067] The bearing 11 supports the shaft body 21 so that it can rotate around the Z axis. Fig. 9 As shown, the bearing 11 has a first bearing 11a and a second bearing 11b. The first bearing 11a and the second bearing 11b are each, for example, a ball bearing. The first bearing 11a and the second bearing 11b are each cylindrical. The center axis of each of the first bearing 11a and the second bearing 11b is the Z axis. That is, the center axis of each of the first bearing 11a and the second bearing 11b is consistent with the center axis of the shaft body 21.

[0068] like Fig. 9 As shown, the second bearing 11b is located closer to the second direction DIR2 than the first bearing 11a. In addition, the first bearing 11a is located in the opposite direction of the second direction DIR2 than the rotor member 22. The second bearing 11b is located closer to the second direction DIR2 than the rotor member 22. The second bearing 11b supports the end of the shaft body 21 in the second direction DIR2.

[0069] like Figure 8 As shown in FIG. 1 , the housing 12 includes a first housing 12a and a second housing 12b. Figure 8 and Fig. 9 As shown, the first housing 12a is cylindrical. The central axis of the first housing 12a is the Z axis. The first housing 12a is located in the opposite direction of the second direction DIR2 than the second housing 12b. In addition, the first housing 12a has an opening OP. As a result, the end of the shaft body 21 in the opposite direction of the second direction DIR2 protrudes from the opening OP in the opposite direction of the second direction DIR2. That is, the brushless motor 100 is a single-axis type.

[0070] The first housing 12a supports the first bearing 11a, the plurality of cores 1, and the plurality of coils 13. The second housing 12b supports the second bearing 11b. The first housing 12a and the second housing 12b are each made of a highly rigid material such as SUS.

[0071] The number of the magnetic cores 14 with coils is 9. The 9 magnetic cores 14 with coils are arranged in the circumferential direction around the Z axis. The 9 magnetic cores 14 with coils are arranged around the hard magnetic body 24 with a gap therebetween.

[0072] The core 1 is magnetized by the magnetic field generated by the hard magnetic body 24 and the magnetic field generated by the coil 13 described later. Fig. 9 As shown, there is a gap (air gap) between the magnetic core 1 and the rotor member 22 .

[0073] A current is supplied from a power source (not shown) to the coil 13. The rotation of the rotor 20 is controlled by controlling the current.

[0074] [Effect]

[0075] According to the magnetic core 1, it is possible to suppress the reduction of the electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil. In more detail, the magnetic core 1 has: a first contact surface CS1, which has a shape protruding and bending in the second direction DIR2 when viewed in the first direction DIR1 where the tooth portion 3 extends; a first convex angle A1, which allows the coil 13 to pass; a first non-contact surface NCS1, the boundary between which and the first contact surface CS1 is the first convex angle A1; and a second contact surface CS2, which has a shape protruding and bending in the third direction DIR3 different from the second direction DIR2 when viewed in the first direction DIR1 where the tooth portion 3 extends. The coil 13 does not contact the first non-contact surface NCS1. Therefore, the bending angle θ1 of the coil 13 between the first convex angle A1 and the second contact surface CS2 is greater than 90 degrees. Therefore, it is possible to alleviate local stress concentration on the insulating film formed on the surface of the coil 13 and suppress damage to the insulating film. As a result, according to the magnetic core 1, it is possible to suppress the reduction in electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil.

[0076] Furthermore, according to the magnetic core 1, the surface area of ​​the outer surface of the magnetic core 1 that is subjected to insulation treatment can be reduced. In more detail, the first non-contact surface NCS1 does not contact the coil 13. Therefore, the first non-contact surface NCS1 does not need to be subjected to insulation treatment. Therefore, according to the magnetic core 1, the surface area of ​​the outer surface of the magnetic core 1 that is subjected to insulation treatment can be reduced. Furthermore, damage to the insulating film formed on the surface of the coil 13 can be suppressed, and therefore, insulation treatment of the entire outer surface of the magnetic core 1 is not required.

[0077] In addition, according to the magnetic core 1, the reduction in electrical insulation between the magnetic core and the coil can be further suppressed. In more detail, the first non-contact surface NCS1 does not contact the coil 13. Therefore, the contact area between the magnetic core 1 and the coil 13 can be reduced. As a result, according to the magnetic core 1, the reduction in electrical insulation between the magnetic core and the coil can be further suppressed.

[0078] In addition, according to the magnetic core 1, it is possible to further suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil. In more detail, the magnetic core 1 also has: a second convex angle A2, which is passed by the coil 13 after passing through the second contact surface CS2; and a second non-contact surface NCS2, and the boundary between it and the second contact surface CS2 is the second convex angle A2. The coil 13 does not contact the second non-contact surface NCS2. As a result, the bending angle θ2 of the coil 13 between the second convex angle A2 and the first contact surface CS1 is greater than 90 degrees. Therefore, it is possible to alleviate the local stress concentration on the insulating film formed on the surface of the coil 13 and suppress the damage to the insulating film. As a result, according to the magnetic core 1, it is possible to suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil.

[0079] Furthermore, according to the magnetic core 1, when the coil is wound around the tooth body portion, it is possible to suppress a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil. The reason for this will be described with reference to the drawings. Fig.10 This is a cross-sectional view of the magnetic core 6 according to the comparative example, when the process of winding the coil 13 around the tooth body portion 31 is viewed from the first direction DIR1. The shape of the magnetic core 6 according to the comparative example is the same as that of the magnetic core 1.

[0080] In the magnetic core 6 involved in the comparative example, when the coil 13 is wound on the tooth body portion 31, the coil 13 contacts the first contact surface CS1, the second convex angle A2, the second contact surface CS2, the first convex angle A1, and the first contact surface CS1 in sequence. That is, the magnetic core 6 involved in the comparative example is different from the magnetic core 1 in that the winding direction of the coil 13 is the opposite direction of the winding direction of the coil 13 of the magnetic core 1. In the case of the magnetic core 6 involved in the comparative example, when the coil 13 moves from the first contact surface CS1 to the second convex angle A2, as shown in FIG. Fig.10 As shown, since the coil 13 contacts the second cam A2, there is a possibility that the insulating film of the coil 13 may be damaged. In addition, when the coil 13 moves from the second contact surface CS2 to the first cam A1, there is a possibility that the insulating film of the coil 13 may be damaged due to the contact between the coil 13 and the first cam A1. Therefore, according to the magnetic core 1, when the coil 13 is wound on the tooth body portion 31, the coil 13 contacts the first contact surface CS1, the first cam A1, the second contact surface CS2, the second cam A2, and the first contact surface CS1 in sequence. In addition, the first cam A1 is located on the first contact surface CS1. Thus, it is possible to prevent the insulating film of the coil 13 from being damaged due to the contact between the coil 13 and the first cam A1 when the coil 13 moves from the first contact surface CS1 to the first cam A1. In addition, the second cam A2 is located above the second contact surface CS2. Therefore, when the coil 13 moves from the second contact surface CS2 to the second convex corner A2, it is possible to suppress the situation where the insulating film of the coil 13 is damaged due to the contact between the coil 13 and the second convex corner A2. Therefore, according to the magnetic core 1, when the coil is wound around the tooth body, it is possible to suppress the situation where the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil.

[0081] In addition, when a magnetic core having an elliptical or circular tooth portion when viewed in the direction in which the tooth portion extends is to be manufactured by press forming, a surface having a first convex angle A1 at the boundary with the first contact surface CS1 and a surface having a second convex angle A2 at the boundary with the second contact surface CS2 are generated. By making the surface having the first convex angle A1 at the boundary with the first contact surface CS1 and the surface having the second convex angle A2 at the boundary with the second contact surface CS2 the first non-contact surface NCS1 and the second non-contact surface NCS2, respectively, which do not contact the coil 13, local stress concentration on the insulating film formed on the surface of the coil 13 can be alleviated, thereby suppressing damage to the insulating film.

[0082] According to the magnetic core 1, it is easy to wind the coil 13 around the tooth body 31. More specifically, the coil 13 contacts the first contact surface CS1 and the second contact surface CS2. When viewed in the first direction DIR1, the first contact surface CS1 and the second contact surface CS2 each have a semi-elliptical shape. In addition, in the process of winding the coil 13, only the coil 13 passes through the first convex corner A1 and the second convex corner A2. Therefore, according to the magnetic core 1, it is easy to wind the coil 13 around the tooth body 31.

[0083] According to the magnetic core 1, in the case of manufacturing the magnetic core by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having end faces of the same shape. In more detail, the radius RCS2 of the second contact surface CS2 is equal to the radius RCS1 of the first contact surface CS1. Thus, the radius of the semi-elliptical portion of the end face of the punch located at a position closer to the second direction DIR2 than the tooth body 31 in the third direction DIR3 and the radius of the semi-elliptical portion of the end face of the punch located at a position closer to the third direction DIR3 than the tooth body 31 in the second direction DIR2 are equal to each other. Therefore, according to the magnetic core 1, in the case of manufacturing the magnetic core by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having end faces of the same shape.

[0084] According to the magnetic core 1, in the case of manufacturing the magnetic core by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having the same shape as each other. In more detail, when viewed in the first direction DIR1, the tooth body portion 31 has a point-symmetrical shape. Thus, when viewed in the first direction DIR1, the end face of the punch located at a position closer to the tooth body portion 31 in the second direction DIR2 in the third direction DIR3 and the end face of the punch located at a position closer to the tooth body portion 31 in the third direction DIR2 in the second direction DIR2 have a point-symmetrical shape. Therefore, according to the magnetic core 1, in the case of manufacturing the magnetic core by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having the same shape as each other.

[0085] [Second embodiment]

[0086] Hereinafter, a magnetic core 1 a according to a second embodiment of the present invention will be described with reference to the drawings. Fig.11 This is a cross-sectional view of the magnetic core 1a as viewed from the first direction DIR1. Fig.12 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.13 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.14This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.15 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.16 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.17 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.18 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig.19 This is a cross-sectional view of a process of winding the coil 13 around the tooth body portion 31 in the magnetic core 1 a as viewed from the first direction DIR1 . Fig. 20 This is a cross-sectional view of the process of winding the coil 13 around the tooth body 31 in the core 1a as viewed from the first direction DIR1. In the core 1a according to the second embodiment, only the parts different from the core 1 according to the first embodiment will be described, and the rest will be omitted.

[0087] like Fig.11 As shown, the tooth body portion 31 has a first contact surface CS1, a first non-contact surface NCS1, a first convex angle A1, a second contact surface CS2, a second convex angle A2, a second non-contact surface NCS2, a third contact surface CS3, a third non-contact surface NCS3, a third convex angle A3, a fourth contact surface CS4, a fourth convex angle A4 and a fourth non-contact surface NCS4.

[0088] like Fig.11 As shown, when observed in the first direction DIR1, the first contact surface CS1 has a shape that is curved protrudingly toward the second direction DIR2. In more detail, when observed in the first direction DIR1, the first contact surface CS1 has a semi-elliptical shape. In addition, the semicircular shape is included in the semi-elliptical shape. In the present embodiment, when observed in the first direction DIR1, the first contact surface CS1 has a semicircular shape. Therefore, when observed in the first direction DIR1, the first contact surface CS1 is a part of a circle with a radius RCS1 centered at the center OCS1.

[0089] like Fig.11As shown, the third contact surface CS3 is located closer to the third direction DIR3 than the first contact surface CS1. In addition, when observed in the first direction DIR1, the third contact surface CS3 has a shape that is curved protrudingly toward the third direction DIR3. In more detail, when observed in the first direction DIR1, the third contact surface CS3 has a semi-elliptical shape. In addition, the semicircular shape is included in the semi-elliptical shape. In the present embodiment, when observed in the first direction DIR1, the third contact surface CS3 has a semicircular shape. Therefore, when observed in the first direction DIR1, the third contact surface CS3 is a part of a circle with a radius RCS3 centered on the center OCS3. The radius RCS3 of the third contact surface CS3 is equal to the radius RCS3 of the first contact surface CS1. In addition, the position of the center OCS3 in the fourth direction DIR4 is different from the position of the center OCS1 in the fourth direction DIR4.

[0090] like Fig.11 As shown, the second contact surface CS2 is disposed between the first contact surface CS1 and the third contact surface CS3. In addition, the second contact surface CS2 is a plane facing the opposite direction of the fourth direction DIR4. That is, the normal direction of the second contact surface CS2 is the opposite direction of the fourth direction DIR4. In this modified example, the second contact surface CS2 is located at a position in the opposite direction of the fourth direction DIR4 than the first contact surface CS1, the third contact surface CS3 and the fourth contact surface CS4.

[0091] like Fig.11 As shown, the first non-contact surface NCS1 is provided between the first contact surface CS1 and the second contact surface CS2. In addition, in this modification, the first non-contact surface NCS1 is a plane facing the second direction DIR2. That is, the normal direction of the first non-contact surface NCS1 is the second direction DIR2.

[0092] In this embodiment, if Fig.11 As shown, when observed in the first direction DIR1, the first convex angle A1 is the angle between the first non-contact surface NCS1 and the second contact surface CS2. More specifically, when observed in the first direction DIR1, the first convex angle A1 protrudes in the radial direction centered on the central axis CA31 of the tooth body 31. Therefore, the boundary between the first non-contact surface NCS1 and the second contact surface CS2 is the first convex angle A1. In this modified example, the first convex angle A1 is 90 degrees.

[0093] like Fig.11As shown, the second non-contact surface NCS2 is located closer to the third direction DIR3 than the first non-contact surface NCS1. Therefore, the second non-contact surface NCS2 is a non-contact surface different from the first non-contact surface NCS1. In more detail, the second non-contact surface NCS2 is arranged between the second contact surface CS2 and the third contact surface CS3. In addition, the second non-contact surface NCS2 is a plane facing the third direction DIR3. That is, the normal direction of the second non-contact surface NCS2 is the third direction DIR3.

[0094] In this embodiment, if Fig.11 As shown, the second convex angle A2 is a convex angle different from the first convex angle A1. In more detail, when observed in the first direction DIR1, the second convex angle A2 is the angle formed by the second contact surface CS2 and the second non-contact surface NCS2. In more detail, when observed in the first direction DIR1, the second convex angle A2 protrudes in the radial direction centered on the central axis CA31 of the tooth body portion 31. Therefore, the boundary between the second non-contact surface NCS2 and the second contact surface CS2 is the second convex angle A2. In this modified example, the second convex angle A2 is 90 degrees.

[0095] like Fig.11 As shown, the fourth contact surface CS4 is disposed between the first contact surface CS1 and the third contact surface CS3. In addition, the fourth contact surface CS4 is a plane facing the fourth direction DIR4. That is, the normal direction of the fourth contact surface CS4 is the fourth direction DIR4. Therefore, the fourth contact surface CS4 is parallel to the second contact surface CS2. In addition, the fourth contact surface CS4 is located closer to the fourth direction DIR4 than the first contact surface CS1, the second contact surface CS2 and the third contact surface CS3.

[0096] like Fig.11 As shown, the third non-contact surface NCS3 is arranged between the third contact surface CS3 and the fourth contact surface CS4. In addition, the third non-contact surface NCS3 is a plane facing the third direction DIR3. That is, the normal direction of the third non-contact surface NCS3 is the third direction DIR3. In this modification, the position of the third non-contact surface NCS3 in the second direction DIR2 is equal to the position of the second non-contact surface NCS2 in the second direction DIR2. In addition, the third non-contact surface NCS3 is located closer to the fourth direction DIR4 than the second non-contact surface NCS2.

[0097] In this embodiment, if Fig.11As shown, the third convex angle A3 is a convex angle different from the first convex angle A1 and the second convex angle A2. In more detail, when observed in the first direction DIR1, the third convex angle A3 is the angle between the third non-contact surface NCS3 and the fourth contact surface CS4. In more detail, when observed in the first direction DIR1, the third convex angle A3 protrudes in the radial direction centered on the central axis CA31 of the tooth body 31. Therefore, the boundary between the third non-contact surface NCS3 and the fourth contact surface CS4 is the third convex angle A3. In this modified example, the third convex angle A3 is 90 degrees.

[0098] like Fig.11 As shown, the fourth non-contact surface NCS4 is located closer to the second direction DIR2 than the third non-contact surface NCS3. Therefore, the fourth non-contact surface NCS4 is a non-contact surface different from the third non-contact surface NCS3. In more detail, the fourth non-contact surface NCS4 is arranged between the fourth contact surface CS4 and the first contact surface CS1. In addition, the fourth non-contact surface NCS4 is a plane facing the second direction DIR2. That is, the normal direction of the fourth non-contact surface NCS4 is the second direction DIR2. In this modification, the position of the fourth non-contact surface NCS4 in the second direction DIR2 is equal to the position of the first non-contact surface NCS1 in the second direction DIR2. In addition, the fourth non-contact surface NCS4 is located closer to the fourth direction DIR4 than the first non-contact surface NCS1.

[0099] In this embodiment, if Fig.11 As shown, the 4th convex angle A4 is a convex angle different from the 1st convex angle A1, the 2nd convex angle A2 and the 3rd convex angle A3. In more detail, when observed in the first direction DIR1, the 4th convex angle A4 is the angle formed by the 4th contact surface CS4 and the 4th non-contact surface NCS4. In more detail, when observed in the first direction DIR1, the 4th convex angle A4 protrudes in the radial direction centered on the central axis CA31 of the tooth body 31. Therefore, the boundary between the 4th non-contact surface NCS4 and the 4th contact surface CS4 is the 4th convex angle A4. In this modified example, the 4th convex angle A4 is 90 degrees.

[0100] like Fig.11 As shown, when viewed in the first direction DIR1, the tooth body portion 31 has a point-symmetrical shape.

[0101] Next, the process of winding the coil 13 on the tooth body 31 will be described. Fig.12 As shown, the coil 13 contacts the first contact surface CS1. That is, the coil 13 contacts the first contact surface CS1 before the coil 13 passes the first convex corner A1.

[0102] Next, if Fig.13As shown, the coil 13 passes through the first convex corner A1. That is, the coil 13 is in contact with the first convex corner A1.

[0103] Next, if Fig.14 As shown, the coil 13 contacts the second contact surface CS2. That is, the coil 13 contacts the second contact surface CS2 after passing through the first convex corner A1. In addition, the coil 13 does not contact the first non-contact surface NCS1. In addition, the bending angle θ1 of the coil 13 at the first convex corner A1 is larger than 90 degrees.

[0104] Next, if Fig.15 As shown, the coil 13 passes through the second convex corner A2. That is, the coil 13 passes through the second convex corner A2 after passing through the second contact surface CS2. In addition, the coil 13 contacts the second convex corner A2.

[0105] Next, if Fig.16 As shown, the coil 13 contacts the third contact surface CS3. That is, the coil 13 contacts the third contact surface CS3 after passing through the second convex angle A2. In addition, the coil 13 does not contact the second non-contact surface NCS2. In addition, the bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3 is greater than 90 degrees. In addition, as shown in FIG. Fig.14 and Fig.16 As shown, the bending angle θ2 of the coil 13 between the second convex corner A2 and the third contact surface CS3 is smaller than the bending angle θ1 of the coil 13 at the first convex corner A1.

[0106] Next, if Fig.17 As shown, the coil 13 passes through the third convex corner A3. That is, the coil 13 passes through the third convex corner A3 after passing through the third contact surface CS3. In addition, the coil 13 contacts the third convex corner A3.

[0107] Next, if Fig.18 As shown, the coil 13 contacts the fourth contact surface CS4. That is, the coil 13 contacts the fourth contact surface CS4 after passing through the third convex angle A3. In addition, the coil 13 does not contact the third non-contact surface NCS3. In addition, the bending angle θ3 of the coil 13 at the third convex angle A3 is greater than 90 degrees.

[0108] Next, if Fig.19 As shown, the coil 13 passes through the fourth convex corner A4. That is, the coil 13 passes through the fourth convex corner A4 after passing through the fourth contact surface CS4. In addition, the coil 13 contacts the fourth convex corner A4.

[0109] Next, if Fig. 20As shown, the coil 13 contacts the first contact surface CS1. That is, the coil 13 contacts the first contact surface CS1 again after passing through the fourth convex angle A4. In addition, the coil 13 does not contact the fourth non-contact surface NCS4. In addition, the bending angle θ4 of the coil 13 between the fourth convex angle A4 and the first contact surface CS1 is greater than 90 degrees.

[0110] By repeating the above process, the coil 13 is wound around the tooth body portion 31 .

[0111] According to the magnetic core 1a, it is possible to suppress the reduction of the electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil. In more detail, the magnetic core 1a has: a first contact surface CS1, which has a shape protruding and bending in the second direction DIR2 when viewed in the first direction DIR1 where the tooth portion 3 extends; a first convex angle A1, which allows the coil 13 to pass; a second contact surface CS2, which allows the coil 13 to pass after passing the first convex angle A1; a first non-contact surface NCS1, the boundary between which and the second contact surface CS2 is the first convex angle A1; a second convex angle A2, which allows the coil 13 to pass after passing the second contact surface CS2; a third contact surface CS3, which has a shape protruding and bending in the third direction DIR3 different from the second direction DIR2 when viewed in the first direction DIR1 where the tooth portion 3 extends; and a second non-contact surface NCS2, the boundary between which and the second contact surface CS2 is the second convex angle A2. The first non-contact surface NCS1 is disposed between the first contact surface CS1 and the second contact surface CS2. In addition, the second non-contact surface NCS2 is disposed between the second contact surface CS2 and the third contact surface CS3. The coil 13 does not contact the first non-contact surface NCS1 and the second non-contact surface NCS2. Thus, the bending angle θ1 of the coil 13 at the first convex angle A1 and the bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3 are each greater than 90 degrees. Therefore, it is possible to alleviate the local stress concentration on the insulating film formed on the surface of the coil 13 and suppress the damage to the insulating film. As a result, according to the magnetic core 1a, it is possible to suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to the damage to the insulating film formed on the surface of the coil.

[0112] In addition, among the stresses applied to the insulating film formed on the surface of the coil 13, the stress applied to the contact portion with the convex corner (first convex corner A1) that the coil 13 first passes through in the process of winding the coil 13 on the tooth body portion 31 is larger. Therefore, the bending angle θ1 of the coil 13 at the first convex corner A1 is greater than the bending angle θ2 of the coil 13 between the second convex corner A2 and the third contact surface CS3, thereby further alleviating stress concentration and suppressing damage to the insulating film.

[0113] According to the magnetic core 1a, it is possible to further suppress the reduction of the electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil. In more detail, the magnetic core 1a also has: a third convex angle A3, which is passed by the coil 13 after passing through the third contact surface CS3; a fourth contact surface CS4, which is passed by the coil 13 after passing through the third convex angle A3; a third non-contact surface NCS3, the boundary between which and the fourth contact surface CS4 is the third convex angle A3; a fourth convex angle A4, which is passed by the coil 13 after passing through the fourth contact surface CS4; and a fourth non-contact surface NCS4, the boundary between which and the fourth contact surface CS4 is the fourth convex angle A4. The coil 13 does not contact the third non-contact surface NCS3 and the fourth non-contact surface NCS4. As a result, the bending angle θ3 of the coil 13 at the third convex angle A3 and the bending angle θ4 of the coil 13 between the fourth convex angle A4 and the first contact surface CS1 are each greater than 90 degrees. Therefore, it is possible to alleviate local stress concentration on the insulating film formed on the surface of the coil 13 and suppress damage to the insulating film. As a result, according to the magnetic core 1a, it is possible to suppress the reduction of electrical insulation between the magnetic core and the coil due to damage to the insulating film formed on the surface of the coil.

[0114] According to the magnetic core 1a, it is easy to wind the coil 13 around the tooth body 31. In more detail, the coil 13 contacts the first contact surface CS1 and the third contact surface CS3. When viewed in the first direction DIR1, the first contact surface CS1 and the third contact surface CS3 each have a semi-elliptical shape. In addition, in the process of winding the coil 13, only the coil 13 passes through each of the first convex corner A1, the second convex corner A2, the third convex corner A3, and the fourth convex corner A4. Therefore, according to the magnetic core 1a, it is easy to wind the coil 13 around the tooth body 31.

[0115] According to the magnetic core 1a, in the case of manufacturing the magnetic core by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having end faces of the same shape. In more detail, the radius RCS3 of the third contact surface CS3 is equal to the radius RCS1 of the first contact surface CS1. Thus, the radius of the semi-elliptical portion of the end face of the punch located at a position closer to the second direction DIR2 than the tooth body 31 in the third direction DIR3 and the radius of the semi-elliptical portion of the end face of the punch located at a position closer to the third direction DIR3 than the tooth body 31 in the second direction DIR2 are equal to each other. Therefore, according to the magnetic core 1a, in the case of manufacturing the magnetic core by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having end faces of the same shape.

[0116] According to the magnetic core 1a, in the case where the magnetic core is manufactured by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having the same shape as each other. In more detail, when viewed in the first direction DIR1, the tooth body portion 31 has a point-symmetrical shape. Thus, when viewed in the first direction DIR1, the end face of the punch located at a position closer to the second direction DIR2 than the tooth body portion 31 in the third direction DIR3 and the end face of the punch located at a position closer to the third direction DIR3 than the tooth body portion 31 in the second direction DIR2 have a point-symmetrical shape. Therefore, according to the magnetic core 1a, in the case where the magnetic core is manufactured by press forming, the tooth body portion can be manufactured by an upper punch and a lower punch having the same shape as each other.

[0117] [First Modification]

[0118] Hereinafter, a magnetic core 1 b according to a first modified example of the present invention will be described with reference to the drawings. Fig.21 This is a cross-sectional view of the magnetic core 1b as viewed from the first direction DIR1. In addition, only the parts of the magnetic core 1b according to the first modification example that are different from the magnetic core 1a according to the second embodiment will be described, and the rest will be omitted.

[0119] like Fig.21 As shown, the core 1b is different from the core 1a in that the second contact surface CS2 is connected to the first non-contact surface NCS1 and the second non-contact surface NCS2 via the notch surface, and the fourth contact surface CS4 is connected to the third non-contact surface NCS3 and the fourth non-contact surface NCS4 via the notch surface.

[0120] In more detail, Fig.21 As shown, the tooth body portion 31 also has a first notch surface NS1, a second notch surface NS2, a third notch surface NS3 and a fourth notch surface NS4. Specifically, the first notch surface NS1, the second notch surface NS2, the third notch surface NS3 and the fourth notch surface NS4 are each a shape obtained by cutting off the first convex angle A1, the second convex angle A2, the third convex angle A3 and the fourth convex angle A4. In addition, in this modified example, the first notch surface NS1, the second notch surface NS2, the third notch surface NS3 and the fourth notch surface NS4 are each planes. Thus, the first non-contact surface NCS1 is connected to the second contact surface CS2 via the first notch surface NS1. The second non-contact surface NCS2 is connected to the second contact surface CS2 via the second notch surface NS2. The third non-contact surface NCS3 is connected to the fourth contact surface CS4 via the third notch surface NS3. The fourth non-contact surface NCS4 is connected to the fourth contact surface CS4 via the fourth notch surface NS4.

[0121] According to the magnetic core 1b, it is possible to further suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil. In more detail, the second contact surface CS2 is connected to the first non-contact surface NCS1 and the second non-contact surface NCS2 respectively via the notch surface. As a result, the bending angle θ1 of the coil 13 at the first convex corner A1 and the bending angle θ2 of the coil 13 between the second convex corner A2 and the third contact surface CS3 can be increased. Therefore, it is possible to alleviate the stress concentration of the insulating film formed on the surface of the coil 13 at the first convex corner A1 and the insulating film formed on the surface of the coil 13 between the second convex corner A2 and the third contact surface CS3, respectively, and suppress the damage to the insulating film formed on the surface of the coil. As a result, according to the magnetic core 1b, it is possible to suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil.

[0122] According to the magnetic core 1b, it is possible to further suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil. In more detail, the fourth contact surface CS4 is connected to the third non-contact surface NCS3 and the fourth non-contact surface NCS4 via the notch surface. As a result, the bending angle θ3 of the coil 13 at the third convex corner A3 and the bending angle θ4 of the coil 13 between the fourth convex corner A4 and the first contact surface CS1 can be increased. Therefore, it is possible to alleviate the stress concentration of the insulating film formed on the surface of the coil 13 at the third convex corner A3 and the insulating film formed on the surface of the coil 13 between the fourth convex corner A4 and the first contact surface CS1, thereby suppressing the damage to the insulating film formed on the surface of the coil. As a result, according to the magnetic core 1b, it is possible to suppress the situation in which the electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating film formed on the surface of the coil.

[0123] [Other embodiments]

[0124] The magnetic core according to the present invention is not limited to the magnetic cores 1, 1a, and 1b, and can be modified within the scope of the gist thereof. In addition, the structures of the magnetic cores 1, 1a, and 1b can be arbitrarily combined.

[0125] The rotary electric machine may have a structure that rotates the rotor by electricity or a structure that generates electricity by the rotation of the rotor. In this case, the rotary electric machine may include at least one of the magnetic cores 1, 1a, 1b, and may have a brush.

[0126] Furthermore, each of the first main surface S1 and the second main surface S2 of the core-back 2 may not have a rectangular shape when viewed in the first direction DIR1.

[0127] In addition, in the magnetic core 1 , the tooth body portion 31 may not have the second convex angle A2 and the second non-contact surface NCS2 .

[0128] Furthermore, in the magnetic core 1 , each of the first contact surface CS1 and the second contact surface CS2 may not have a semi-elliptical shape when viewed in the first direction DIR1 .

[0129] In addition, the second direction DIR2 may not be orthogonal to the first direction DIR1. In addition, the second direction DIR2 may not be a direction along the rotation axis of the brushless motor 100 when the core 1 is incorporated into the brushless motor 100.

[0130] In addition, the first non-contact surface NCS1 may not be a plane facing the third direction DIR3 in the magnetic core 1. Therefore, the first non-contact surface NCS1 may be a plane facing a direction different from the third direction DIR3 or may be a curved surface.

[0131] In addition, the third direction DIR3 may not be the opposite direction to the second direction DIR2.

[0132] Furthermore, in the magnetic core 1 , when viewed in the first direction DIR1 , the first convex angle A1 may not be an angle formed by tangent lines between the first contact surface CS1 and the first non-contact surface NCS1 at the first convex angle A1 .

[0133] In addition, the first convex angle A1, the second convex angle A2, the third convex angle A3, and the fourth convex angle A4 may not be 90 degrees.

[0134] In addition, in the magnetic core 1 , the radius RCS2 of the second contact surface CS2 may be different from the radius RCS1 of the first contact surface CS1 .

[0135] In addition, the second non-contact surface NCS2 may not be a plane facing the second direction DIR2 in the magnetic core 1. Therefore, the second non-contact surface NCS2 may be a plane facing a direction different from the second direction DIR2, or may be a curved surface.

[0136] Furthermore, in the magnetic core 1 , when viewed in the first direction DIR1 , the second convex angle A2 may not be an angle formed by tangent lines between the second contact surface CS2 and the second non-contact surface NCS2 at the second convex angle A2 .

[0137] Furthermore, the tooth body portion 31 may not have a point-symmetrical shape when viewed in the first direction DIR1.

[0138] Furthermore, each of the third main surface S3 and the fourth main surface S4 of the tooth tip portion 32 may not have a rectangular shape when viewed in the first direction DIR1.

[0139] In addition, the outer edge O2 of the core back 2 observed in the first direction DIR1 may not surround the outer edge O31 of the tooth body 31 observed in the first direction DIR1. In addition, the outer edge O32 of the tooth tip 32 observed in the first direction DIR1 may not surround the outer edge O31 of the tooth body 31 observed in the first direction DIR1.

[0140] In addition, the brushless motor 100 may be an outer rotor type.

[0141] In addition, the brushless motor 100 is not limited to a single-shaft type, and the brushless motor 100 may be a dual-shaft type, for example.

[0142] In addition, each of the first bearing 11 a and the second bearing 11 b is not limited to a ball bearing.

[0143] In addition, the material of each of the first housing 12a and the second housing 12b may be a material having high rigidity.

[0144] In addition, the number of the magnetic cores 14 with coils is not limited to nine.

[0145] In the core 1 a , the tooth body portion 31 may not have the third lobed corner A3 , the fourth lobed corner A4 , the fourth contact surface CS4 , the third non-contact surface NCS3 , and the fourth non-contact surface NCS4 .

[0146] Furthermore, in the magnetic core 1 a , each of the first contact surface CS1 and the third contact surface CS3 may not have a semi-elliptical shape when viewed in the first direction DIR1 .

[0147] In addition, in the magnetic core 1 a , the radius RCS3 of the third contact surface CS3 may be different from the radius RCS1 of the first contact surface CS1 .

[0148] In the core 1a, the second contact surface CS2 may not be a plane facing in the direction opposite to the fourth direction DIR4. Therefore, the second contact surface CS2 may be a plane facing in a direction different from the direction opposite to the fourth direction DIR4, or may be a curved surface.

[0149] In addition, in the magnetic core 1a, the first non-contact surface NCS1 may not be a plane facing the second direction DIR2. Therefore, the first non-contact surface NCS1 may be a plane facing a direction different from the second direction DIR2, or may be a curved surface.

[0150] Furthermore, in the magnetic core 1 a , the first convex angle A1 may not be the angle formed by the first non-contact surface NCS1 and the second contact surface CS2 when viewed in the first direction DIR1 .

[0151] In addition, in the magnetic core 1a, the second non-contact surface NCS2 may not be a plane facing the third direction DIR3. Therefore, the second non-contact surface NCS2 may be a plane facing a direction different from the third direction DIR3, or may be a curved surface.

[0152] Furthermore, in the magnetic core 1 a , the second convex angle A2 may not be an angle formed by the second contact surface CS2 and the second non-contact surface NCS2 when viewed in the first direction DIR1 .

[0153] In the core 1a, the fourth contact surface CS4 may not be a plane facing the fourth direction DIR4. Therefore, the fourth contact surface CS4 may be a plane facing a direction different from the fourth direction DIR4, or may be a curved surface.

[0154] In the magnetic core 1a, the third non-contact surface NCS3 may not be a plane facing the third direction DIR3. Therefore, the third non-contact surface NCS3 may be a plane facing a direction different from the third direction DIR3 or may be a curved surface.

[0155] Furthermore, in the magnetic core 1 a , the position of the third non-contact surface NCS3 in the second direction DIR2 may be different from the position of the second non-contact surface NCS2 in the second direction DIR2 .

[0156] Furthermore, in the magnetic core 1 a , the third convex angle A3 may not be an angle formed by the third non-contact surface NCS3 and the fourth contact surface CS4 when viewed in the first direction DIR1 .

[0157] In the core 1a, the fourth non-contact surface NCS4 may not be a plane facing the second direction DIR2. Therefore, the fourth non-contact surface NCS4 may be a plane facing a direction different from the second direction DIR2, or may be a curved surface.

[0158] Furthermore, in the magnetic core 1 a , the position of the fourth non-contact surface NCS4 in the second direction DIR2 may be different from the position of the first non-contact surface NCS1 in the second direction DIR2 .

[0159] Furthermore, in the magnetic core 1 a , the fourth convex angle A4 may not be an angle formed by the fourth contact surface CS4 and the fourth non-contact surface NCS4 when viewed in the first direction DIR1 .

[0160] In the magnetic core 1 a , the bending angle θ2 of the coil 13 between the second convex corner A2 and the third contact surface CS3 may not be smaller than the bending angle θ1 of the coil 13 at the first convex corner A1 .

[0161] In the magnetic core 1b, the first convex corner A1, the second convex corner A2, the third convex corner A3 or the fourth convex corner A4 may be chamfered. That is, the first notch surface NS1, the second notch surface NS2, the third notch surface NS3 and the fourth notch surface NS4 may each be a curved surface.

[0162] In the core 1b, the tooth body portion 31 may not have the third notch surface NS3 and the fourth notch surface NS4. That is, the fourth contact surface CS4 may be connected to the third non-contact surface NCS3 and the fourth non-contact surface NCS4 without the notch surface.

[0163] The present invention has the following structure.

[0164] (1) A magnetic core is a magnetic core used in a rotating electrical machine, comprising a tooth portion, the tooth portion having a shape extending in a first direction, the tooth portion including a wound portion on which a coil is wound, the wound portion having: a first cam, which is a first contact surface for the coil to contact before passing through the first cam, and having a shape protrudingly bent in a second direction when viewed in the first direction; a first non-contact surface, which is a first non-contact surface that the coil does not contact, and the first cam is located at the boundary between the first non-contact surface and the first contact surface; and a second contact surface, which is a second contact surface for the coil to contact after passing through the first cam, and having a shape protrudingly bent in a third direction different from the second direction when viewed in the first direction.

[0165] (2) In the magnetic core described in (1), the wound portion further comprises: a second convex angle, which is a convex angle different from the first convex angle and is passed by the coil after passing through the second contact surface; and a second non-contact surface, which is a second non-contact surface that the coil does not contact, and the boundary between the second non-contact surface and the second contact surface is the second convex angle, and the coil contacts the first contact surface again after passing through the second convex angle.

[0166] (3) In the magnetic core described in (1) or (2), each of the first contact surface and the second contact surface has a semi-elliptical shape when viewed in the first direction.

[0167] (4) In the magnetic core described in (3), the radius of the first contact surface and the radius of the second contact surface are equal to each other.

[0168] (5) In the magnetic core according to any one of (1) to (4), the wound portion has a point-symmetrical shape when viewed in the first direction.

[0169] (6) A magnetic core is a magnetic core used in a rotating electrical machine, comprising a tooth portion, wherein the tooth portion has a shape extending in a first direction, the tooth portion includes a wound portion on which a coil is wound, and the wound portion has: a first cam, which allows the coil to pass through during the process of winding the coil; a first contact surface, which is the first contact surface for the coil to contact before passing through the first cam, and has a shape protrudingly bent in a second direction when viewed in the first direction; a second contact surface, which is the first contact surface for the coil to contact after passing through the first cam; and a first non-contact surface, which is the first non-contact surface provided between the first contact surface and the second contact surface and which the coil does not contact, and the first non-contact surface The boundary between the surface and the above-mentioned second contact surface is the above-mentioned first convex angle; the second convex angle, which is a convex angle different from the above-mentioned first convex angle and is provided for the above-mentioned coil to pass after passing through the above-mentioned second contact surface; and the third contact surface, which is the third contact surface for the above-mentioned coil to contact after passing through the above-mentioned second convex angle, and when observed in the above-mentioned first direction, has a shape protrudingly bent in a third direction different from the above-mentioned second direction; and the second non-contact surface, which is a non-contact surface different from the above-mentioned first non-contact surface, and is a second non-contact surface arranged between the above-mentioned second contact surface and the above-mentioned third contact surface and not contacted by the above-mentioned coil, and the boundary between the second non-contact surface and the above-mentioned second contact surface is the above-mentioned second convex angle.

[0170] (7) In the magnetic core described in (6), the wound portion further comprises: a third convex angle, which is a convex angle different from the first convex angle and the second convex angle, and is provided for the coil to pass through after passing through the third contact surface; a fourth contact surface, which is provided for the coil to contact after passing through the third convex angle; a third non-contact surface, which is a third non-contact surface provided between the third contact surface and the fourth contact surface and is not contacted by the coil, and the third convex angle is provided at the boundary between the third non-contact surface and the fourth contact surface; and the fourth convex angle is provided at the boundary between the third non-contact surface and the fourth contact surface. Angle, which is a convex angle different from the above-mentioned first convex angle, the above-mentioned second convex angle and the above-mentioned third convex angle, and is provided for the above-mentioned coil to pass through after passing through the above-mentioned fourth contact surface; and a fourth non-contact surface, which is a non-contact surface different from the above-mentioned third non-contact surface, and is a fourth non-contact surface arranged between the above-mentioned fourth contact surface and the above-mentioned first contact surface and not in contact with the above-mentioned coil, and the boundary between the fourth non-contact surface and the above-mentioned fourth contact surface is the above-mentioned fourth convex angle, and the above-mentioned coil contacts the above-mentioned first contact surface again after passing through the above-mentioned fourth convex angle.

[0171] (8) In the magnetic core described in (6) or (7), the first contact surface and the third contact surface each have a semi-elliptical shape when viewed in the first direction.

[0172] (9) In the magnetic core described in (8), the radius of the first contact surface and the radius of the third contact surface are equal to each other.

[0173] (10) In the magnetic core described in any one of (6) to (9), the wound portion has a point-symmetrical shape when viewed in the first direction.

[0174] (11) In the magnetic core described in any one of (6) to (10), the second contact surface is connected to each of the first non-contact surface and the second non-contact surface via a notch surface.

[0175] (12) In the magnetic core described in (7), the fourth contact surface is connected to each of the third non-contact surface and the fourth non-contact surface via a notch surface.

[0176] (13) In the magnetic core described in any one of (1) to (12), the teeth are formed of soft magnetic powder.

[0177] (14) A magnetic core with a coil, comprising the magnetic core according to any one of (1) to (13) and the coil.

[0178] (15) A rotating electrical machine comprising the magnetic core according to any one of (1) to (13).

[0179] (16) A brushless motor comprising the core according to any one of (1) to (13).

[0180] Description of Reference Numerals

[0181] 1, 1a, 1b...magnetic core; 2...back of the core; 3...tooth; 10...stator assembly; 11...bearing; 11a...first bearing; 11b...second bearing; 12...housing; 12a...first housing; 12b...second housing; 13...coil; 14...magnetic core with coil; 20...rotor; 21...shaft; 22...rotor member; 23...soft magnetic body; 24...hard magnetic body; 31...tooth body; 32...tooth end; 100...brushless motor; A1...first lobe; A2...second lobe; A3...third lobe; A4...fourth lobe; CA31...center axis; CS1...first contact surface; CS2...second contact surface; CS3...third contact surface; C S4...the 4th contact surface; DIR1...the 1st direction; DIR2...the 2nd direction; DIR3...the 3rd direction; DIR4...the 4th direction; NCS1...the 1st non-contact surface; NCS2...the 2nd non-contact surface; NCS3...the 3rd non-contact surface; NCS4...the 4th non-contact surface; NS1...the 1st notch surface; NS2...the 2nd notch surface; NS3...the 3rd notch surface; NS4...the 4th notch surface; O2, O31, O32...the outer edge; OCS1, OCS2, OCS3...the center; OP...the opening; RCS1, RCS2, RCS3...the radius; S1...the 1st principal surface; S2...the 2nd principal surface; S3...the 3rd principal surface; S4...the 4th principal surface; θ1, θ2, θ3, θ4...the bending angle.

Claims

1. A magnetic core used in a rotating electrical machine, characterized in that: The device comprises a tooth portion, wherein the tooth portion has a shape extending in a first direction, The tooth portion includes a wound portion around which a coil is wound, The wound portion comprises: a first convex corner through which the coil passes during winding of the coil; a first contact surface, which is a first contact surface for the coil to contact before passing through the first convex corner, and has a shape that is curved so as to protrude in a second direction when viewed in the first direction; a first non-contact surface, which is a first non-contact surface that the coil does not contact, and a boundary between the first non-contact surface and the first contact surface is the first convex corner; and The second contact surface is a second contact surface with which the coil contacts after passing through the first convex corner, and has a shape that is curved so as to protrude in a third direction different from the second direction when viewed in the first direction.

2. The magnetic core according to claim 1, characterized in that The wound portion further comprises: a second convex angle which is different from the first convex angle and through which the coil passes after passing through the second contact surface; and a second non-contact surface, which is a second non-contact surface that the coil does not contact, and a boundary between the second non-contact surface and the second contact surface is the second convex corner, The coil comes into contact with the first contact surface again after passing through the second convex corner.

3. The magnetic core according to claim 1 or 2, characterized in that: When viewed in the first direction, the first contact surface and the second contact surface each have a semi-elliptical shape.

4. The magnetic core according to claim 3, characterized in that: The radius of the first contact surface and the radius of the second contact surface are equal to each other.

5. The magnetic core according to any one of claims 1 to 4, characterized in that: The wound portion has a point-symmetrical shape when viewed in the first direction.

6. A magnetic core used in a rotating electrical machine, characterized in that: The device comprises a tooth portion, wherein the tooth portion has a shape extending in a first direction, The tooth portion includes a wound portion around which a coil is wound, The wound portion comprises: a first convex corner through which the coil passes during winding of the coil; a first contact surface, which is a first contact surface for the coil to contact before passing through the first convex corner, and has a shape that is curved so as to protrude in a second direction when viewed in the first direction; a second contact surface for the coil to contact after passing through the first convex corner; a first non-contact surface, which is disposed between the first contact surface and the second contact surface and is not in contact with the coil, and the boundary between the first non-contact surface and the second contact surface is the first convex corner; a second convex angle, which is a convex angle different from the first convex angle and is provided for the coil to pass through after passing through the second contact surface; a third contact surface which the coil contacts after passing through the second convex corner and has a shape protrudingly curved in a third direction different from the second direction when viewed in the first direction; and The second non-contact surface is different from the first non-contact surface, and is a second non-contact surface that is arranged between the second contact surface and the third contact surface and is not in contact with the coil, and the boundary between the second non-contact surface and the second contact surface is the second convex angle.

7. The magnetic core according to claim 6, characterized in that: The wound portion further comprises: a third convex angle which is different from the first convex angle and the second convex angle and through which the coil passes after passing through the third contact surface; a fourth contact surface for the coil to contact after passing through the third convex corner; a third non-contact surface, which is disposed between the third contact surface and the fourth contact surface and is not in contact with the coil, and the boundary between the third non-contact surface and the fourth contact surface is the third convex corner; a fourth convex angle that is different from the first convex angle, the second convex angle, and the third convex angle, and through which the coil passes after passing through the fourth contact surface; and a fourth non-contact surface, which is different from the third non-contact surface and is disposed between the fourth contact surface and the first contact surface and is not in contact with the coil, and the boundary between the fourth non-contact surface and the fourth contact surface is the fourth convex corner, The coil comes into contact with the first contact surface again after passing through the fourth convex corner.

8. The magnetic core according to claim 6 or 7, characterized in that: When viewed in the first direction, the first contact surface and the third contact surface each have a semi-elliptical shape.

9. The magnetic core according to claim 8, characterized in that: The radius of the first contact surface and the radius of the third contact surface are equal to each other.

10. The magnetic core according to any one of claims 6 to 9, characterized in that: The wound portion has a point-symmetrical shape when viewed in the first direction.

11. The magnetic core according to any one of claims 6 to 10, characterized in that: The second contact surface is connected to each of the first non-contact surface and the second non-contact surface via a notch surface.

12. The magnetic core according to claim 7, characterized in that: The fourth contact surface is connected to each of the third non-contact surface and the fourth non-contact surface via a notch surface.

13. The magnetic core according to any one of claims 1 to 12, characterized in that: The tooth portion is a molded body formed of soft magnetic powder.

14. A magnetic core with a coil, characterized in that: have: The magnetic core according to any one of claims 1 to 13 and the coil.

15. A rotating electrical machine, characterized in that: A magnetic core according to any one of claims 1 to 13 is provided.

16. A brushless motor, characterized in that: A magnetic core according to any one of claims 1 to 13 is provided.

Images