Method for manufacturing a stator core

Abstract

The present invention stabilizes the quality of a stator core in the manufacture of the stator core and shortens the processing time of the stator core. The present invention is a manufacturing method of a stator core including a plurality of teeth for coil winding, a tooth connecting portion connecting adjacent teeth, and a first annular portion provided with a plurality of fitting portions fitting each of the plurality of teeth at an inner peripheral portion. The manufacturing method includes: (a) a process of punching the plurality of teeth and the tooth connecting portion formed integrally as an inner core (a second annular portion) from a sheet material; (b) a process of performing a non-magnetic treatment on a portion of the sheet material corresponding to the tooth connecting portion before the inner core is punched; and (c) a process of fitting the first annular portion to the inner core using the plurality of fitting portions.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a stator core for a rotating electric motor. Background Technology

[0002] As a stator core for rotary motors such as brushless motors, a stator core is known to have: an annular toothed member comprising a plurality of teeth; and an annular yoke member disposed outside the annular toothed member. As an example of a manufacturing method for this stator core, a method is known to be used whereby the annular toothed member and the annular yoke member are formed separately, and after a coil is wound onto each of the plurality of teeth of the annular toothed member, the annular toothed member is fitted with the annular yoke member. In this manufacturing method, the coil is mounted on each tooth of the annular toothed member before fitting the annular toothed member with the annular yoke member, thus allowing the coil to be easily mounted on each tooth.

[0003] Furthermore, Patent Document 1 discloses an example of a method for manufacturing a stator core as described above.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-115965 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The annular toothed member constituting the stator core as described above has multiple teeth and tooth connecting portions connecting the multiple teeth. Sometimes, magnetic flux leakage occurs between the teeth in the tooth connecting portions. If magnetic flux leakage occurs between the teeth in a rotating electric motor, there is a concern that the output characteristics of the rotating electric motor will be reduced.

[0009] Patent Document 1 describes a method for reducing magnetic flux leakage between teeth by performing a non-magnetic process on the tooth connection portions of an annular toothed member. Specifically, Patent Document 1 describes a method for forming an annular toothed member by stacking core sheets obtained from sheet metal through stamping, and then performing a non-magnetic process on the annular toothed member. In this case, after forming the annular toothed member, all the tooth connection portions of the annular toothed member are subjected to a non-magnetic process, which is time-consuming. Furthermore, even if the core sheets before stacking are subjected to a non-magnetic process, the processing time is still required corresponding to the number of core sheets being stacked, raising concerns about the increased time required for the non-magnetic process.

[0010] Furthermore, if additional processing is performed on the core blanks or stacks of core blanks obtained from the sheet metal, there is a concern that the dimensions of the core blanks or stacks may change.

[0011] The purpose of this invention is to provide a method for manufacturing a stator core that achieves stable quality and reduces processing time.

[0012] Technical means to solve the problem

[0013] One embodiment of the present invention is a method for manufacturing a stator core, the stator core being wound with a coil, the stator core comprising: a plurality of teeth for winding the coil; a tooth connecting portion for connecting adjacent teeth among the plurality of teeth; and a first annular portion having a plurality of engaging portions on its inner periphery that engage with the plurality of teeth; the method for manufacturing the stator core comprising: (a) a step of punching a second annular portion formed integrally from the plurality of teeth and the tooth connecting portion from a sheet metal; (b) a step of performing a non-magnetic treatment on the portion of the sheet metal corresponding to the tooth connecting portion before punching the second annular portion; and (c) a step of engaging the plurality of teeth with the plurality of engaging portions, thereby making the first annular portion and the second annular portion integral.

[0014] The effects of the invention

[0015] According to the present invention, the quality of the stator core can be stabilized and the processing time of the stator core can be shortened. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing a sunroof device mounted on the roof of a vehicle.

[0017] Figure 2 This is a perspective view of a motor device according to an embodiment of the present invention.

[0018] Figure 3 It means assembled into Figure 2 A three-dimensional view of the meshing state of the worm and worm wheel formed on the shaft of the brushless motor in the motor device shown.

[0019] Figure 4 It is along Figure 3 A cross-sectional view along line AA.

[0020] Figure 5 It means Figure 4 A top view showing the shape of the outer iron core of the stator core.

[0021] Figure 6 It means Figure 4 A top view showing the shape of the inner iron core of the stator core.

[0022] Figure 7It indicates that it is used for punching. Figure 6 The top view of the plate material with the inner iron core shown.

[0023] Figure 8 It means Figure 7 A magnified top view of part A.

[0024] Figure 9 It indicates punching. Figure 6 A top view of the markings on the inner iron core as shown.

[0025] Explanation of symbols

[0026] 10: Sunroof installation

[0027] 11: Top cover plate

[0028] 12: Vehicles

[0029] 13: Top Cover

[0030] 14: Opening

[0031] 15a, 15b: Hoof slices

[0032] 16: Guide rail

[0033] 17a, 17b: Drive cables

[0034] 18: Front window glass

[0035] 20: Motor unit

[0036] 21: Brushless Motor

[0037] 22: Rotor core

[0038] 23: Magnet

[0039] 23a: outer peripheral surface

[0040] 23b: Magnetic flux

[0041] 24: Rotor

[0042] 25: Stator core

[0043] 26: Toothed connection part

[0044] 27: Axis

[0045] 28: Coil

[0046] 29: Stator

[0047] 30: Teeth

[0048] 30a: Protrusion

[0049] 31: Axis of rotation

[0050] 32: Terminal

[0051] 33: Insulating film

[0052] 34: Board material

[0053] 35: Outer iron core (first annular part)

[0054] 35a: Fitting part

[0055] 36: Inner iron core (second annular section)

[0056] 36a: Non-magnetic body

[0057] 36b: Pattern

[0058] 36c: Cross section (marker)

[0059] 37: Laser

[0060] 40: Gear section

[0061] 41: Gear housing

[0062] 41a: Worm Gear Housing

[0063] 42: Worm Gear

[0064] 42a: Serrated section

[0065] 42b: Output gear

[0066] 43: Worm shaft

[0067] 43a: Worm gear

[0068] 44: Ball bearings Detailed Implementation

[0069] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0070] First, the motor device mounted on the brushless motor of this embodiment will be described. For example... Figure 1 As shown, the sunroof device 10 includes a top cover plate 11. The top cover plate 11 opens and closes through an opening 14 formed in the top cover 13 of the vehicle 12. A pair of shoe plates 15a and 15b are fixed to both sides of the top cover plate 11 along the vehicle width direction (vertical direction in the figure). Furthermore, guide rails 16 extending along the longitudinal direction (left-right direction in the figure) of the vehicle 12 are fixed to both sides of the opening 14 of the top cover 13 along the vehicle width direction. By guiding the pair of shoe plates 15a and 15b to the corresponding pair of guide rails 16, the top cover plate 11 can move freely in the longitudinal direction of the vehicle 12, i.e., open and close freely.

[0071] Each of the shoe 15b located on the rear side (right side of the figure) of the vehicle 12 is connected to one end of a geared drive cable 17a, 17b. The other ends of these drive cables 17a, 17b are wrapped around the front side of the vehicle 12 (left side of the figure) further than the opening 14.

[0072] On the front side of the vehicle 12, a motor unit 20 is mounted inside the top cover 13, which is positioned between the opening 14 and the front glass 18. The other ends of a pair of drive cables 17a and 17b are engaged with an output gear 42b located in the motor unit 20. When the motor unit 20 is driven, a pair of shoe plates 15a and 15b move in opposite directions as the output gear 42b rotates. As a result, the top cover 11 is automatically opened and closed by being pushed and pulled by the pair of drive cables 17a and 17b via the pair of shoe plates 15b.

[0073] Next, the motor device 20 of this embodiment will be described. Furthermore, in the following description, "axial" refers to the direction of the rotation axis of the motor shaft, "circumferential" refers to the circumferential direction of the shaft, and "radial" refers to the radial direction of the shaft.

[0074] like Figure 2 As shown, the motor assembly 20 includes a brushless motor 21 and a gear section 40. The brushless motor 21 has a stator 29, which includes... Figure 4 The diagram shows an annular stator core 25 and a coil (wire) 28 wound around the stator core 25. The stator core 25 has a plurality of teeth 30 extending radially inward. The brushless motor 21 has a rotor 24 rotatably disposed inside the teeth 30. The rotor 24 has a rotor core 22 and a circular magnet 23 disposed around the outer periphery of the rotor core 22. Furthermore, the brushless motor 21 has a shaft 27 disposed radially inward of the stator core 25 and surrounding it. Figure 3 The rotation axis 31 shown rotates. Furthermore, the rotor core 22 is fixed to the shaft 27 and has the rotation axis 31 as its radial center. Figure 3 As shown, shaft 27 is rotatably supported by ball bearing 44.

[0075] Moreover, such as Figure 4 As shown, the stator core 25 includes a plurality of teeth 30 protruding radially inward from the inner circumference of the stator core 25, and a coil 28 is wound around each of the plurality of teeth 30 via an insulating film 33.

[0076] Next, as Figure 2As shown, a gear housing 41 is provided in the gear section 40. The opening of the gear housing 41 is closed by a gear cover (not shown). The gear cover is formed into a generally flat plate shape using a resin material such as plastic, and can be easily installed on the gear housing 41 by a snap-fit ​​structure.

[0077] Furthermore, a worm wheel receiving portion 41a is provided in the gear housing 41. The worm wheel receiving portion 41a is recessed in the thickness direction of the gear housing 41 and on the side opposite to the gear cover side. The worm wheel 42, which forms the reduction mechanism, is rotatably received in the worm wheel receiving portion 41a.

[0078] The worm gear 42 is formed into a roughly circular plate shape using resin materials such as plastic. On the radially outer side of the worm gear 42, such as... Figure 3 As shown, a serrated portion 42a is formed, which meshes with a worm 43a mounted on a worm shaft 43 connected to the shaft 27. Furthermore, the axial base end of an output gear 42b is fixed at the rotation center of the worm gear 42. Here, the output gear 42b is made of steel, and its axial middle portion is rotatably oriented from... Figure 2 The gear housing 41 shown is supported by a boss portion. Furthermore, the axial head end of the output gear 42b extends outward from the gear housing 41, thereby engaging with the other ends of a pair of drive cables 17a, 17b (see reference). Figure 1 ).

[0079] Here, the operation of the motor device 20 will be explained.

[0080] In the motor unit 20, from the outside via Figure 2 The power supplied to the controller board (not shown) via the terminal 32 shown is selectively supplied to... Figure 4 The brushless motor 21 shown has coils 28. Thus, a predetermined interlocking magnetic flux is formed in the stator 29 (tooth 30), generating magnetic attraction or repulsion between this interlocking magnetic flux and the effective magnetic flux formed by the magnets 23 disposed in the rotor core 22. As a result, the rotor core 22 rotates continuously.

[0081] Furthermore, when the rotor core 22 rotates, it is in harmony with... Figure 3 The worm shaft 43, which is integral with the shaft 27 shown, rotates, and consequently, the worm wheel 42, which meshes with the worm shaft 43, rotates. Furthermore, the output gear 42b connected to the worm wheel 42 rotates, thereby enabling the drive of necessary electrical components, etc.

[0082] Next, the coiled magnet 23 installed in the brushless motor 21 of this embodiment will be described. Figure 4As shown, the magnet 23 is magnetized in such a way that N poles or S poles are formed on the outer peripheral surface 23a of the outer periphery of the magnet 23 facing each of the plurality of teeth 30. The magnet 23 magnetized in this way is also called a pole-oriented magnet 23. Specifically, for the coil-shaped magnet 23, as a method to increase the magnetic flux 23b, anisotropic magnetization is applied, in which magnetic poles are formed on the outer peripheral surface 23a of the outer periphery of the magnet 23. As a result, N poles or S poles are formed on the outer peripheral surface 23a facing each of the plurality of teeth 30. Furthermore, in the brushless motor 21 magnetized by the anisotropic magnetization, no magnetic flux leakage to the inside of the coil-shaped magnet 23 occurs, so it is not necessary to place a magnetic body inside the coil-shaped magnet 23. Moreover, the magnetization method of the magnet 23 is not limited to anisotropic magnetization; for example, a magnetization method in which the magnetization orientation is radially oriented in the radial direction of the coil-shaped magnet 23 can also be applied.

[0083] Next, the detailed structure of the stator core 25 of the brushless motor 21 in this embodiment will be described. For example... Figure 4 As shown, the stator core 25 includes: a plurality of teeth 30 for winding the coil 28; a tooth connecting portion 26 for connecting adjacent teeth 30; and an annular outer core (first annular portion) 35, with a plurality of engaging portions 35a provided on its inner circumference for engaging with each of the plurality of teeth 30. Furthermore, the plurality of teeth 30 and the tooth connecting portion 26 are integrally formed into an annular inner core (second annular portion) 36. The inner core 36 is disposed inside the outer core 35 and engages with the outer core 35 using the plurality of engaging portions 35a. That is, the stator core 25 of this embodiment includes two divided annular cores, namely the outer core 35 and the inner core 36, and the outer core 35 and the inner core 36 are engaged together.

[0084] like Figure 5 As shown, the outer iron core 35 is formed in a ring shape, for example, containing an ferrous metal. On the inner periphery of the outer iron core 35, a number of concave fitting portions 35a are formed at predetermined equal intervals, corresponding to the number of teeth 30 installed.

[0085] like Figure 6 As shown, the inner core 36 is also formed in a ring shape, for example, containing an ferrous metal. A plurality of teeth 30 are provided at predetermined equal intervals on the outer periphery of the inner core 36. Tooth connecting portions 26 are arranged between adjacent teeth 30, and each tooth 30 and the tooth connecting portion 26 are integrally formed. Furthermore, a protrusion 30a is provided at the outer end of each tooth 30, which can engage with the fitting portion 35a of the outer core 35.

[0086] Furthermore, in the stator core 25 of this embodiment, each of the plurality of tooth connection portions 26 in the inner iron core 36 is provided with a non-magnetic body portion 36a. The non-magnetic body portion 36a is formed by performing a non-magnetic treatment near the circumferential center of each tooth connection portion 26. By forming a non-magnetic body portion 36a near the center of the tooth connection portion 26, magnetic flux 23b between the teeth 30 (see reference) can be prevented in the tooth connection portion 26. Figure 4 Leakage. Furthermore, the location of the non-magnetic body portion 36a in the toothed connection portion 26 is not limited to the vicinity of the circumferential center of the toothed connection portion 26.

[0087] In this embodiment, the non-magnetization treatment is performed by punching or other processes from the material described later. Figure 7 The plate 34 is used in its state before punching the stator core 25 laminations. The plate 34 contains, for example, an ferrous metal. The demagnetization process is performed, for example, by irradiating with a laser 37. Alternatively, the demagnetization process may also form a predetermined processing strain in the plate 34. In either case of laser irradiation or the formation of processing strain, by forming a nonmagnetic body portion 36a, leakage of magnetic flux 23b between the teeth 30 in the tooth connection portion 26 can be prevented, thereby preventing the deterioration of the magnetic characteristics of the brushless motor 21.

[0088] Next, the manufacturing method of the stator core 25 of this embodiment will be described.

[0089] First, such as Figure 7 and Figure 8 As shown, for plate 34 containing ferrous metals, Figure 6 The portion corresponding to the toothed connection portion 26 of the inner iron core 36 shown is subjected to a non-magnetic treatment. For example, as the non-magnetic treatment, a predetermined pattern 36b including the non-magnetic body portion 36a is formed on the plate 34 by irradiating the plate 34 before punching the inner iron core 36 with a laser 37.

[0090] In this embodiment, the specified pattern 36b is a pattern 36b formed by repeatedly forming multiple non-magnetic body portions 36a, each of which is formed as a line. As an example, such as... Figure 7 As shown, Figure 8 The pattern 36b of the three linear non-magnetic body portions 36a shown is repeatedly formed along the longitudinal and transverse directions of the plate 34. In this embodiment, as... Figure 8 The pattern 36b shown, which includes three linear non-magnetic body portions 36a, corresponds to one inner iron core 36. The linear pattern 36b of the non-magnetic body portions 36a is formed in such a way that it corresponds to the vicinity of the central portion of each of the plurality of tooth connecting portions 26 of the inner iron core 36.

[0091] In addition, such as Figure 9 As shown, a cross portion 36c is formed where the three linear non-magnetic body portions 36a intersect with the inner iron core 36. The cross portion 36c is equivalent to the center of the annular inner iron core 36.

[0092] After irradiating the plate 34 with a laser 37 to repeatedly form a predetermined pattern 36b containing three line-shaped non-magnetic body parts 36a along the longitudinal and transverse directions of the plate 34, the pattern is then processed by a device having a laser 37. Figure 6 The inner core 36 is punched by stamping to create its shape. For example, as shown... Figure 9 As shown, the inner core 36 is punched from the sheet metal 34, marked by the intersection 36c where the three linear non-magnetic body parts 36a intersect. That is, the intersection 36c is used as the center point of the annular inner core 36, and the punching process is performed with the pattern 36b containing the three linear non-magnetic body parts 36a aligned with the shape of the inner core 36. Figure 6 The inner iron core 36 has the shape shown. Thus, a core stamp with a plurality of inner iron cores 36 having a non-magnetic body portion 36a formed near the center of each tooth connection portion 26 can be obtained from the plate 34.

[0093] Furthermore, by stacking a specified number of core laminations of the inner core 36, a structure is formed as shown in the figure. Figure 6 Each toothed connection portion 26 shown has a ring-shaped inner iron core 36 of a specified thickness formed near its central portion, consisting of a non-magnetic body portion 36a.

[0094] Furthermore, such as Figure 4 As shown, the coil 28 is wound around each tooth 30 of the inner core 36. At this time, in the inner core 36, the portion between adjacent teeth 30 opens outward, so the nozzle of the coil winding machine can easily move up, down, left and right around the periphery of each tooth 30, thereby shortening the winding time of the coil 28.

[0095] On the other hand, multiple core blanks of the outer core 35 are obtained by punching the outer core 35 from another sheet material, etc. Furthermore, by stacking a predetermined number of core blanks of the outer core 35, a structure is formed as shown in the image. Figure 5 The inner periphery shown has an outer iron core 35 of a specified thickness having multiple fitting portions 35a.

[0096] Furthermore, the inner iron core 36, in which coils 28 are wound on each tooth 30, is fitted with the outer iron core 35, which includes multiple fitting portions 35a, thereby making the inner iron core 36 and the outer iron core 35 a single unit. That is, the stator core 25 is formed. At this time, the protrusions 30a at the head ends of each tooth 30 of the inner iron core 36 are fitted into the fitting portions 35a on the inner periphery of the outer iron core 35 to form the stator core 25.

[0097] In the stator core 25 manufacturing method of this embodiment, before punching the core laminations of the inner core 36 from the sheet metal 34 by stamping or other punching processes, the portion of the sheet metal 34 corresponding to the tooth connection portion 26 of the inner core 36 is subjected to a non-magnetic treatment. Therefore, at the point of punching, a non-magnetic body portion 36a has already been formed in the core lamination of the inner core 36. Therefore, compared with the case where the non-magnetic treatment is performed after punching the core laminations, it is not necessary to perform the non-magnetic treatment on each of the multiple tooth connection portions 26 individually, thereby reducing the processing time for the non-magnetic treatment and significantly shortening the processing time required to form the inner core 36.

[0098] Furthermore, since there is no need to perform additional processing on the core blanks or stacks of core blanks of the inner core 36 obtained by punching from the sheet metal 34, concerns about changes in the dimensions of the core blanks or stacks of the inner core 36 can be eliminated. That is, the dimensional accuracy of the inner core 36 punched by stamping can be directly maintained.

[0099] As a result, the quality of the stator core 25 can be stabilized, and the processing time of the stator core 25 can be shortened.

[0100] Furthermore, since the non-magnetic portion 36a is formed on the sheet metal 34 in the form of a predetermined pattern 36b, the intersections 36c of the pattern 36b can also be used as markings during punching. Moreover, by forming the non-magnetic portion 36a on the sheet metal 34 in the form of a predetermined pattern 36b, it is also possible to correspond to skew. For example, in order to utilize the characteristics of the motor, it is sometimes desirable to change the position of the non-magnetic portion 36a in the stator core 25 relative to the center of the tooth connection portion 26. However, in the manufacturing method of the stator core 25 of this embodiment, when punching the inner iron core 36 on the sheet metal 34, the position of the non-magnetic portion 36a can be shifted relative to the center of the tooth connection portion 26 simply by slightly changing the punching position.

[0101] In other words, in the manufacturing method of the stator core 25 of this embodiment, the forming position of the non-magnetic body portion 36a can be set to various positions, thereby being able to correspond to changes in the characteristics of the motor. Furthermore, in the method of forming the non-magnetic body portion 36a from a punched stator core, it is very difficult to change the position of the non-magnetic body portion 36a after punching.

[0102] Furthermore, in the inner core 36 of the stator core 25 of this embodiment, a plurality of teeth 30 and tooth connecting portions 26 are integrally formed. As a result, the rigidity of the inner core 36 can be ensured, and the number of parts of the inner core 36 can be reduced.

[0103] Furthermore, by irradiating the non-magnetic body portion 36a with the laser 37, the non-magnetic body portion 36a can be easily and with high precision in a short time.

[0104] Furthermore, in the above embodiment, the case where the non-magnetic body portion 36a is formed by irradiating the laser 37 is described, but the non-magnetic body portion 36a can also be formed by processing strain or the like.

[0105] Of course, the present invention is not limited to the described embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in the described embodiments, the outer iron core 35 of the stator core 25 of the brushless motor 21 assembled into the motor device 20 may also be circular.

[0106] Furthermore, in the described embodiment, the magnet 23 assembled inside the brushless motor 21 is described as a circular magnet 23, but the magnet 23 may also be a plurality of segmented magnets 23 installed on the outer periphery of the rotor core 22.

[0107] Furthermore, in the described embodiment, the brushless motor 21 is mounted on the motor device 20, but the brushless motor 21 may also be a motor for driving power windows, etc.

Claims

1. A method for manufacturing a stator core, wherein the stator core is to be wound with coils, the method for manufacturing the stator core being characterized in that, The stator core includes: Multiple teeth for winding the coil; A toothed connection portion connects adjacent teeth among the plurality of teeth; as well as The first annular portion has multiple engaging portions on its inner circumference that engage with the multiple teeth; The method for manufacturing the stator core includes: a) The process of punching the plurality of teeth and the tooth connection portion from the sheet metal to form a second annular portion; b. A process of performing a non-magnetic treatment on the portion of the sheet metal corresponding to the toothed connection portion before punching the second annular portion; and c. The process of engaging the plurality of teeth with the plurality of engaging portions, thereby making the first annular portion and the second annular portion a single unit. In step b, the non-magnetic treatment is performed by forming a predetermined pattern on the sheet material using the non-magnetic body portion formed by the non-magnetic treatment. The specified pattern is formed by repeatedly forming multiple linear non-magnetic body parts. In step a, the second annular portion is punched from the sheet metal, with the intersection of the plurality of linear non-magnetic body portions as a mark.

2. The method for manufacturing a stator core according to claim 1, characterized in that, In step b, as part of the non-magnetic treatment, the plate is irradiated with a laser.

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