WO2019159847A1

WO2019159847A1 - Method for manufacturing core member, and core member

Info

Publication number: WO2019159847A1
Application number: PCT/JP2019/004683
Authority: WO
Inventors: 武本田
Original assignee: 日本電産株式会社
Priority date: 2018-02-13
Filing date: 2019-02-08
Publication date: 2019-08-22
Also published as: CN111742472A

Abstract

[Problem] To provide a method for manufacturing a disk-shaped core member with which it is possible to improve roundness. [Solution] This method for manufacturing a core member is for manufacturing a disk-shaped stator core member 32 which constitutes a cylindrical stator core 31. This method for manufacturing a core member includes: a core member forming step for leaving, as a connecting section 52 on a steel plate 50, a section of the outer peripheral side of the stator core member 32 not requiring outer diameter dimensional accuracy, while forming, on the steel plate 50 by punching, a section of the outer peripheral side of the stator core member 32 requiring outer diameter dimensional accuracy and excluding the connecting section 52; and, after the core member forming step, a core member separating step for separating the stator core member 32 from the steel plate 50 by cutting off the connecting section 52.

Description

Core member manufacturing method and core member

The present invention relates to a core member manufacturing method and a core member.

As a motor core member manufacturing method, a method is known in which a steel plate is punched into a stator core or rotor core shape by a press device or the like. Thus, a plurality of stator cores or rotor cores punched from the steel plate are laminated in the thickness direction. *

As a method for manufacturing the core member as described above, for example, a method for manufacturing a stator iron core plate for a rotating electrical machine disclosed in Patent Document 1 is known. In this method of manufacturing a stator iron core plate for a rotating electrical machine, the center hole in the iron core plate is formed by punching in the first step, and the outer frame portion of the iron core plate is aligned in the next second step. A slit is formed by punching. *

Thereby, the internal stress and the process distortion which arise in each process process following the said 2nd process are absorbed effectively by the said slit. Therefore, a stator iron core plate with high dimensional accuracy can be obtained by the manufacturing method disclosed in Patent Document 1. *

As a method for manufacturing the core member as described above, for example, a method for manufacturing a stator core of a motor disclosed in Patent Document 2 is known. In this stator core manufacturing method, a stator core is formed by laminating a single core punched from a stator material along a punching line. In the stator core manufacturing method, a slit is provided on the punching line for the stator material, and then the inner diameter center of the single core is punched from the stator material. By the manufacturing method of the stator core, a non-punched portion that is not punched is formed between the slits. *

By providing the non-punched portion in the stator material, when the inner diameter portion of the single core is punched from the stator material, the opening of the slit is suppressed and the rigidity of the stator material is reinforced. it can. Thereby, the roundness of the inner diameter portion of the single core can be effectively increased.

Japanese Unexamined Patent Publication No. 63-1347 JP 2005-198361 A

In the case of an inner rotor type motor, generally, a cylindrical stator core is disposed in a casing of the motor. Therefore, the outer diameter of the stator core is required to have high dimensional accuracy with respect to the inner surface of the casing. Further, the outer diameter of the cylindrical rotor core disposed in the stator is also required to have high dimensional accuracy. Similarly, in the case of a motor on the outer rotor side, high dimensional accuracy is required for the outer diameter of the cylindrical stator core and the outer diameter of the cylindrical rotor core. *

By the way, when the core member which comprises a core is punched from a steel plate, the said steel plate will elongate in the case of punching. Since the steel sheet is generally formed by rolling, the material properties differ depending on the rolling direction. Therefore, when a disk-shaped core member having a circular outer shape is punched from the steel plate, the outer shape of the core member becomes elliptical. That is, the roundness of the disk-shaped core member is likely to be reduced by punching from the steel plate. *

The outer shape of the stator core obtained by the manufacturing method disclosed in

Patent Documents

1 and 2 is a rectangular shape. Further, the outer shape of the stator core does not require high dimensional accuracy like the above-described disk-shaped core member. Furthermore, in the manufacturing methods disclosed in

Patent Documents

1 and 2 described above, slits are formed in the steel sheet in order to improve the dimensional accuracy of the center hole of the core member. Therefore, in the manufacturing methods disclosed in

Patent Documents

1 and 2 described above, it is difficult to ensure the roundness of the core member having a circular outer shape. *

The objective of this invention is providing the manufacturing method of the disk shaped core member which can improve roundness.

The core member manufacturing method which concerns on one Embodiment of this invention is a manufacturing method of the disk shaped core member which comprises a columnar or cylindrical core. In this core member manufacturing method, the outer diameter side of the core member is not connected to the outer peripheral side of the core member, and the outer diameter dimension of the outer peripheral side of the core member is other than the connecting portion while leaving a portion that does not require accuracy of the outer diameter dimension. A core member forming step for forming a portion that requires accuracy of the steel sheet by punching, and a core member separating step for cutting the core member from the steel plate by cutting the connecting portion after the core member forming step. And having.

According to the core member manufacturing method according to an embodiment of the present invention, the roundness of the disk-shaped core member can be improved.

FIG. 1 is an exploded perspective view showing a schematic configuration of a motor according to the embodiment. FIG. 2 is a plan view showing a schematic configuration of the stator core member. FIG. 3 is a view of portion A of FIG. 2 as viewed from the direction of the arrow. FIG. 4 is a flow showing a method for manufacturing the stator core member. FIG. 5 is a plan view showing a state in which a plurality of slits are formed in the steel plate. FIG. 6 is a plan view showing a state where the stator core member is formed on the steel plate. FIG. 7 is a plan view showing a state in which the stator core member is separated from the steel plate. FIG. 8 is a cross-sectional view schematically showing a state in which a steel plate is punched out using a punch and a die. FIG. 9 is a cross-sectional view schematically showing a state in which a steel plate is punched out using a punch and a die.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same or an equivalent part in a figure, and the description is not repeated. Moreover, the dimension of the structural member in each figure does not faithfully represent the actual dimension of the structural member, the dimensional ratio of each structural member, or the like. *

In the following description, the direction extending from the center of the stator core to the outer peripheral side in plan view is referred to as “radial direction”, and the direction along the outer periphery of the stator core is referred to as “circumferential direction”. However, the definition of this direction is not intended to limit the direction of use of the motor according to the present invention. *

In the following description, the expressions “fixed”, “connected”, “attached”, etc. (hereinafter “fixed”, etc.) are not only used when the members are directly fixed, but also via other members. This includes cases where they are fixed. That is, in the following description, expressions such as fixation include the meanings of direct and indirect fixation between members. *

(Configuration of Motor) FIG. 1 shows a schematic configuration of the motor 1 including the stator core 31 according to the embodiment of the present invention. The motor 1 includes a rotor 2, a stator 3, and a housing 4. The rotor 2 rotates about the central axis P with respect to the stator 3. In the present embodiment, the motor 1 is a so-called inner rotor type motor in which a rotor 2 is disposed in a cylindrical stator 3 so as to be rotatable about a central axis P. *

The rotor 2 includes a shaft 20, a rotor core 21, and a magnet 22. The rotor 2 is arranged on the radially inner side of the stator 3 and is rotatable with respect to the stator 3. *

In the present embodiment, the rotor core 21 has a cylindrical shape extending along the central axis P. The rotor core 21 is configured by laminating a plurality of electromagnetic steel plates formed in a predetermined shape in the thickness direction. *

A shaft 20 extending along the central axis P is fixed to the rotor core 21 in a state of penetrating in the axial direction. Thereby, the rotor core 21 rotates together with the shaft 20. In the present embodiment, a plurality of magnets 22 are disposed in the rotor core 21 at predetermined intervals in the circumferential direction. The magnet 22 may be disposed on the outer peripheral surface of the rotor core 21. *

The stator 3 is accommodated in the housing 4. In the present embodiment, the stator 3 has a cylindrical shape, and the rotor 2 is disposed on the radially inner side. That is, the stator 3 is arranged to face the rotor 2 in the radial direction. The rotor 2 is disposed on the radially inner side of the stator 3 so as to be rotatable about the central axis P. *

The stator 3 includes a stator core 31 (core) and a stator coil (not shown). In the present embodiment, the stator core 31 has a cylindrical shape extending in the axial direction. The stator core 31 has a plurality of disk-shaped stator core members 32 (core members) formed in a predetermined shape and stacked in the thickness direction. *

The stator core 31 has a cylindrical yoke 31a and a plurality of teeth 31b extending radially inward from the yoke 31a. In the example illustrated in FIG. 2, the stator core 31 includes twelve teeth 31 b. The stator core 31 is accommodated in the cylindrical casing 4. A stator coil (not shown) is wound on a bracket (not shown) made of an insulating material (for example, an insulating resin material) attached to the teeth 31b of the stator core 31. *

FIG. 2 is a plan view showing a schematic configuration of the stator core member 32. FIG. 3 is a view of portion A of FIG. 2 in the stator core member 32 as seen from the direction of the arrow. That is, FIG. 3 is a view of a part of the stator core member 32 as viewed from the outside in the radial direction. *

As shown in FIG. 2, the stator core member 32 is an annular plate member. The stator core member 32 includes an annular yoke portion 32 a that constitutes the yoke 31 a of the stator core 31 and a plurality of tooth portions 32 b that constitute the teeth 31 b of the stator core 31. Each tooth portion 32 b extends radially inward from the yoke portion 32. *

As shown in FIG. 2, some of the plurality of teeth 32 b have caulking portions 32 c for caulking and fixing the plurality of stator core members 32 stacked in the thickness direction. *

The stator core member 32 is not shown in the casing 4 in a state where the arc portion 33 (punching portion) constituting a part of the outer periphery and the stator core 31 are disposed in the casing 4 on the outer periphery side of the yoke portion 32a. And a recess 34 (connection cutting portion) in which the positioning member is positioned. *

The recesses 34 are positioned at predetermined intervals in the circumferential direction on the outer peripheral side of the stator core member 32. The arc portion 33 is located between the recess portions 34. That is, the arc portions 33 and the recesses 34 are alternately positioned in the circumferential direction on the outer peripheral side of the stator core member 32. *

Since the yoke 31a of the stator core 31 is disposed in the casing 4 as described above, the outer diameter of the arc portion 33 of the yoke portion 32a in the stator core member 32 requires dimensional accuracy. Therefore, the arc portion 33 of the stator core member 32 is a portion that requires the accuracy of the outer diameter. On the other hand, the concave portion 34 of the stator core member 32 is not required to have a higher accuracy in outer diameter than the arc portion 33. *

In addition, the part which needs the precision of an external dimension is a part from which the roundness of an external shape is requested | required when the stator core member 32 is punched out from a steel plate on the performance of the motor 1 among the stator core members 32. . The portion that does not require the accuracy of the outer dimensions is a portion of the stator core member 32 that does not require the roundness of the outer shape when the stator core member 32 is punched from the steel plate due to the performance of the motor 1. *

As will be described in detail later, in the manufacturing process of the stator core member 32, the arc portion 33 of the stator core member 32 is formed by punching the steel plate before the recess 34. Therefore, as shown in FIG. 3, the outer peripheral surface, which is the processed surface 35 of the arc portion 33 of the stator core member 32, has a shear surface 35a and a fracture surface 35b in order in the punching direction with respect to the steel plate (the arrow direction in FIG. 3). Have. This is because, as will be described later, since the arc portion 33 of the stator core member 32 is formed by punching a slit in the steel plate, the processed surface 35 of the arc portion 33 remaining on the steel plate side at the time of punching is formed in the first half of the punching process. This is because the fracture surface 35b is formed later in the punching process after the shear surface 35a is formed. *

On the other hand, the concave portion 34 is formed when the stator core member 32 is separated from the steel plate after the arc portion 33 is formed, as will be described later. Therefore, as shown in FIG. 3, the outer peripheral surface which is the processed surface 36 of the recessed part 34 has the fracture surface 36b and the shear surface 36a in order in the punching direction (arrow direction of FIG. 3) with respect to a steel plate. As will be described later, since the stator core member 32 is punched by punching when the recess 34 is punched, a shear surface 36a is formed on the processing surface 36 of the recess 34 by the die in the first stage of punching. This is because the fracture surface 36b is formed later in the punching process.

Here, the arc portion 33 has a shear surface 35a and a fracture surface 35b in order in the punching direction from the steel plate 50 on the processed surface 35 of the outer peripheral side of the stator core member 32 that requires the accuracy of the outer diameter. It is the punching part which has. The concave portion 34 is a connection cutting portion having a fracture surface 36b and a shear surface 36a in order in the punching direction on the processing surface 36 of the outer peripheral side of the stator core member 32 where the accuracy of the outer diameter dimension is unnecessary. is there. *

Note that the shear surfaces 35a and 36a are surfaces in which a shear strain is burned by the tool when the tool bites into the steel plate. The fracture surfaces 35b and 36b are surfaces on which crystal grain surfaces appear by cracking when a steel plate is punched out with a tool. *

(Manufacturing Method of Stator Core Member) Next, a manufacturing method of the stator core member 32 will be described with reference to FIGS. FIG. 4 is a flowchart showing an outline of a method for manufacturing the stator core member 32. FIG. 5 is a plan view showing a state in which a plurality of slits 51 are formed in the steel plate 50. FIG. 6 is a plan view showing a state where the stator core member 32 is formed on the steel plate 50. FIG. 7 is a plan view showing a state in which the stator core member 32 is separated from the steel plate 50. 8 and 9 are cross-sectional views schematically showing a state in which the steel plate 50 is punched out using the punch T1 and the die T2. *

5 to 7, the steel plate 50 is a square plate member in plan view. However, the steel plate 50 may be a strip-shaped member. *

First, as shown in FIG. 5, a plurality of slits 51 for forming a plurality of arc portions 33 located on the outer peripheral side of the stator core member 32 are formed in the steel plate 50 by punching. This step is the slit forming step (step S1) in FIG. That is, a plurality of arc-shaped slits 51 arranged in the circumferential direction are formed in the steel plate 50 by punching an arc-shaped member having a predetermined width in the radial direction from the steel plate 50. Thereby, the connection part 52 is formed in the steel plate 50 between the slits 51 in the circumferential direction of the arc-shaped slit 51, respectively. That is, in the steel plate 50, the plurality of slits 51 and the plurality of connection portions 52 are alternately arranged in the circumferential direction. In the present embodiment, as shown in FIG. 5, the connection portion 52 is located on the outer peripheral side of the yoke portion 32 a of the stator core member 32 and radially outward with respect to the tooth portion 32 b. *

In the steel plate 50, a region surrounded by the plurality of slits 51 constitutes the stator core member 32. *

By forming the slit 51 by punching the steel plate 50 as described above, the inner peripheral side of the slit 51 constitutes the outer peripheral side of the arc portion 33 of the stator core member 32. A member that is punched when the slit 51 is formed in the steel plate 50 is punched by a punch. On the other hand, the part which comprises the stator core member 32 among the steel plates 50 remains on the die. *

As described above, by forming the plurality of slits 51 in the steel plate 50 by punching, the stator core member 32 is left with a portion that does not require the accuracy of the outer diameter dimension as the connection portion 52 in the steel plate 50, and the stator. A portion of the core member 32 other than the connection portion 52 that requires the accuracy of the outer diameter can be formed in the steel plate 50 by punching. The slit forming step corresponds to the core member forming step. *

Here, when the steel plate 50 is punched using the punch T1 and the die T2, the punch T1 approaches the die T2 as shown in FIGS. 8 and 9, so that the steel plate 50 is sandwiched between the punch T1 and the die T2. The broken part is broken. The direction in which the punch T1 approaches the die T2 is the punching direction (the direction of the white arrow in FIGS. 8 and 9). *

As shown in FIG. 8, when the steel plate 50 is punched using the punch T1 and the die T2, first, the shear surfaces D2a and D1a are formed on the steel plate 50 by the punch T1 and the die T2. In the punching process, the time when the shear surfaces D2a and D1a are formed is the first half of the punching process. Thereafter, as the punch T1 further approaches the die T2, as shown in FIG. 9, the member M1 is punched out by the punch T1, while the member M2 remains on the die T2. At this time, fracture surfaces D2b and D1b are formed. In the punching process, the time when the fracture surfaces D2b and D1b are formed is the latter stage of the punching process. *

Therefore, as shown in FIG. 9, a shear surface D2a and a fracture surface D2b are formed in order in the punching direction (the direction of the white arrow in the figure) on the processed surface D2 of the member M2 remaining on the die T2. On the other hand, a fracture surface D1b and a shear surface D1a are formed in order in the punching direction on the processed surface D1 of the member M1 punched by the punch T1. *

Therefore, when the slit 51 is formed by punching the steel plate 50 as described above, the processing surface 35 located on the outer peripheral side of the arc portion 33 of the stator core member 32 corresponds to the processing surface D2 in FIG. , In order, have a shear surface 35a and a fracture surface 35b. *

After forming the plurality of slits 51 in the steel plate 50, as shown in FIG. 6, the yoke portion 32a and the plurality of teeth portions 32b are formed in the steel plate 50 by punching. This process is the slot punching process (step S2) in FIG. *

Thereafter, as shown in FIG. 7, the connecting portion 52 located between the slits 51 is punched out to form a recess 34 on the outer peripheral side of the yoke portion 32 a of the stator core member 32, and the steel plate 50 to the stator. The core member 32 is separated. In FIG. 7, the punched portion of the connecting portion 52 is indicated by a broken line. The step of separating the stator core member 32 from the steel plate 50 by punching the connection portion 52 is the connection portion separation step (step S3) in FIG. *

As described above, after forming the plurality of slits 51 in the steel plate 50 by punching, the stator core material 32 is separated from the steel plate 50 by cutting the connecting portion 52. The connection part separation step corresponds to a core member separation step. *

Since the stator core member 32 is punched by punching when the connection portion 52 is punched as described above, the processing surface 36 located on the outer peripheral side of the recess 34 corresponds to the processing surface D1 in FIG. In order, it has the fracture surface 36b and the shearing surface 36a. *

As described above, when the stator core member 32 is punched from the steel plate 50, first, after forming the plurality of slits 51 in the steel plate 50, the entire outer shape of the stator core member is formed at a time by punching the connection portion 52. Compared to the case of punching, the dimensional accuracy of the arc portion 33 of the stator core member 32 formed by the slit 51 can be improved. *

That is, when the entire outer shape of the stator core member is formed by punching, the stator core member becomes elliptical due to the elongation at the time of punching. On the other hand, as described above, the portion requiring the accuracy of the outer dimension of the stator core member 32 is formed by punching while leaving the portion that does not need the accuracy of the outer dimension of the stator core member 32 as the connecting portion 52. Thereby, it can suppress that elongation arises in the part for which the precision of the external dimension of the stator core member 32 is required. *

Thereby, in the stator core member 32, the required dimensional accuracy of the circular arc part 33 is securable. Then, when separating the stator core member 32 from the steel sheet 50, the stator core member is cut by cutting the connecting portion 52 that is located between the slits 51 and does not require high dimensional accuracy compared to the arc portion 33. The dimensional accuracy of the stator core member 32 can be improved as compared with the case of punching out the outer shape at once. *

Therefore, since the stator core member 32 can be prevented from becoming elliptical when punched from the steel plate 50 by the above-described method for manufacturing the stator core member 32, the roundness of the stator core member 32 can be improved. *

In the present embodiment, the stator core 31 is accommodated in the casing 4. Thus, the fixed core member 32 that constitutes the stator core 31 and is accommodated in the casing 4 needs accuracy of at least a part of the outer dimension on the outer peripheral side. By the manufacturing method described above, a stator core member having a high accuracy of the outer diameter can be obtained. *

Other Embodiments Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented without departing from the spirit of the invention. *

In the embodiment, the outer peripheral side of the arc portion 33 of the stator core member 32 is formed by forming the slit 51 in the steel plate 50. However, after punching the steel plate in the thickness direction in the shape of the arc part of the stator core member, the arc part of the stator core member is formed by a so-called pushback process in which the punched part is returned to the original position. Also good. *

In the said embodiment, after forming the some slit 51 in the steel plate 50, the teeth part 32b and the yoke part 32a are formed. However, a plurality of slits 51 may be formed in the steel plate 50 after the teeth portion 32 b and the yoke portion 32 a are formed in the steel plate 50. *

In the embodiment, the manufacturing method applied when the stator core member 32 is punched from the steel plate 50 has been described. However, the manufacturing method of the above embodiment may be applied when punching out the disk-shaped rotor core member constituting the rotor core. For example, when the through hole of the rotor core through which the shaft 20 passes is formed, the manufacturing method of the above embodiment may be applied. *

In the above embodiment, the motor 1 is a so-called inner rotor type motor in which the rotor 2 is disposed in the cylindrical stator 3 so as to be rotatable about the central axis P. However, the motor may be a so-called outer rotor type motor in which a cylindrical stator is disposed in a cylindrical rotor. Also in this case, the manufacturing method of the above-described embodiment can be applied to at least one of the stator core member constituting the stator core and the rotor core member constituting the rotor core. *

In the embodiment, the motor is a so-called permanent magnet motor. In the permanent magnet motor, the rotor has a magnet. However, the motor 1 may be a motor that does not have a magnet, such as an induction machine, a reluctance motor, a switched reluctance motor, or a wound field type motor.

The present invention is applicable to a method of manufacturing a disk-shaped stator core member that constitutes a stator core by being laminated in the thickness direction.

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotor 3 Stator 4 Housing 20 Shaft 21 Rotor core 22 Magnet 31 Stator core (core) 31a Yoke 31b Teeth 32 Stator core member (core member) 32a Yoke part

32b Teeth part

32c Caulking part 33 Arc part (Punched portions) 35a, 36a, D1a, D2a Shear surfaces 35b, 36b, D1b, D2b Fracture surface 34, Recessed portion (connection cutting portion) 35, 36 Work surface 50 Steel plate 51 Slit 52 Connection portion P Center axis D1, D2 Work surface T1 Punch T2 Die M1 Member punched by punch M2 Member remaining on die

Claims

A method of manufacturing a disk-shaped core member constituting a columnar or cylindrical core, wherein a portion of the outer peripheral side of the core member that does not require accuracy of an outer diameter dimension is left as a connection portion on a steel plate, A core member forming step of forming a portion of the outer peripheral side of the core member that requires outside diameter accuracy other than the connecting portion by punching the steel sheet, and the connecting portion is cut after the core member forming step. And a core member separation step of separating the core member from the steel plate.
2. The core member manufacturing method according to claim 1, wherein in the core member forming step, the steel plate is punched out, along the portion of the outer peripheral side of the core member that requires accuracy of the outer diameter dimension. The core member manufacturing method which forms a slit.
The core member manufacturing method according to claim 1 or 2, wherein the core member is a stator core member constituting a stator core.
A disk-shaped core member, which is laminated after being punched from a steel plate, and has a sheared surface in order in the direction of punching from the steel plate on the processed surface of the outer peripheral side where accuracy of the outer diameter is required And a punched part having a fractured surface, and a connecting cut part having a fractured surface and a shearing surface in order in the punching direction on the processed surface of the outer peripheral side where the accuracy of the outer diameter dimension is unnecessary Element.
The core member according to claim 4, wherein the core member is a stator core member that constitutes a stator core and is accommodated in a casing.