阅读说明：本技术 定子芯体板制造方法、定子芯体板、定子芯体以及模具 (Stator core plate manufacturing method, stator core plate, stator core, and mold ) 是由 本田武 于 2020-01-31 设计创作，主要内容包括：一种定子芯体板的制造方法,定子芯体板具有从圆盘状的主体部向径向外侧延伸的突出部,所述制造方法包括下述工序：突出部形成工序,按照包含突出部的外形的至少一部分的形状对钢板的一部分进行冲裁,形成突出部的外形的至少一部分；以及主体部形成工序,按照与形成于钢板的突出部的外形连续的形状对钢板进行冲裁,形成主体部。(A method for manufacturing a stator core plate having a protrusion extending radially outward from a disk-shaped main body, the method comprising: a protruding portion forming step of punching out a part of the steel sheet in a shape including at least a part of an outer shape of the protruding portion to form at least a part of the outer shape of the protruding portion; and a main body forming step of punching the steel plate in a shape continuous with the outer shape of the protruding portion formed on the steel plate to form the main body.)

1. A method for manufacturing a stator core plate having a protrusion extending radially outward from a disk-shaped main body, comprising:

a protruding portion forming step of punching out a part of a steel plate in a shape including at least a part of an outer shape of the protruding portion to form at least a part of the outer shape of the protruding portion; and

and a main body portion forming step of punching the steel plate in a shape continuous with an outer shape of a protruding portion formed on the steel plate to form the main body portion.

2. The method of manufacturing a stator core plate according to claim 1,

in the protruding portion forming step, a recess is formed in an outer shape portion of the protruding portion.

3. The method of manufacturing a stator core plate according to claim 1 or 2,

in the main body forming step, the main body is formed by punching or retraction.

4. A stator core plate having a protrusion extending radially outward from a disk-shaped main body portion,

the arrangement of the fracture surface and the shear surface in the thickness direction at least a part of the outer edge of the protrusion is different from the arrangement of the fracture surface and the shear surface at the outer edge of the main body in the thickness direction.

5. The stator core plate according to claim 4,

the main body portion has a recess at a connection portion with the protruding portion.

6. A stator core characterized in that the stator core is formed by laminating the stator core plates according to claim 4 or 5 in the thickness direction.

7. A mold for forming a stator core plate having a protrusion extending radially outward from a disk-shaped main body, comprising:

a first punched portion that punches out a part of the steel plate in a shape including at least a part of an outer shape of the protruding portion; and

and a body portion die that punches out the body portion and that has a gap from the protruding portion.

Technical Field

The invention relates to a stator core plate manufacturing method, a stator core plate, a stator core and a mold.

Background

As a method of manufacturing a stator core of a motor, it is known to laminate a plurality of stator core plates, each of which is formed by punching a steel plate into a shape of a stator core by a press machine or the like, in a thickness direction. In the stator core manufactured by the above method, a protruding portion for providing a mounting hole or the like may be formed on the outer periphery. In this case, the stator core plate is manufactured by punching a steel plate into the shape of the stator core having the protruding portion.

As in the stator core plate having the protruding portion, when the steel plate is punched out by a die, the protruding portion of the sheet metal member having the protruding portion in the vicinity of the outer edge may be plastically deformed. As factors of deformation of the protruding portion, there are variations in distribution of punching stress and variations in distribution of strength of the protruding portion due to contact between the protruding portion and the die when the steel sheet is punched by the die.

As a manufacturing method for preventing the deformation of the protruding portion, for example, as disclosed in patent document 1, a manufacturing method of a sheet metal member is known in which a portion having a strength lower than that of the protruding portion is formed around the protruding portion. In this manufacturing method, after the window portion is punched out on the body portion side of the protruding portion, the overall external shape including the protruding portion and the body portion is formed. That is, the main body portion is formed with a portion having a strength lower than that of the protruding portion, and then the entire outer shape is formed. Thus, even when the projecting portion comes into contact with the die, the portion having a lower strength than the projecting portion is elastically deformed at first, and therefore, plastic deformation of the projecting portion can be prevented.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-087279

Disclosure of Invention

Technical problem to be solved by the invention

In the case of manufacturing a portion having a strength lower than that of the protruding portion as in the structure disclosed in patent document 1, it is necessary to form a punched hole or the like in the main body side. However, the stator core manufactured by the above-described manufacturing method may generate a space that obstructs the magnetic flux from passing through the main body portion of the stator core, and thus, the magnetic flux density generated in the stator core may be reduced.

The invention aims to provide a method for manufacturing a stator core plate, which can prevent plastic deformation of a protruding part without forming a space for reducing magnetic flux density in a main body part.

Technical scheme for solving technical problem

A stator core plate manufacturing method according to an embodiment of the present invention is a manufacturing method of a stator core plate having a protruding portion extending radially outward from a disk-shaped main body portion. The method for manufacturing the stator core plate comprises the following steps: a protruding portion forming step of punching out a part of a steel plate in a shape including at least a part of an outer shape of the protruding portion to form at least a part of the outer shape of the protruding portion; and a main body portion forming step of punching the steel plate in a shape continuous with an outer shape of a protruding portion formed on the steel plate to form the main body portion.

Effects of the invention

According to the method of manufacturing the stator core plate according to the embodiment of the present invention, the plastic deformation of the protruding portion can be prevented without forming a space for reducing the magnetic flux density in the main body portion.

Drawings

Fig. 1 is a view schematically showing a schematic configuration of a motor according to an embodiment in a cross section including a central axis.

Fig. 2 is a perspective view showing a schematic structure of the stator core.

Fig. 3 is a plan view showing a schematic structure of the stator core plate.

Fig. 4 is a flowchart showing a method of manufacturing the stator core.

Fig. 5 is a plan view showing an electromagnetic steel sheet on which a projection is formed.

Fig. 6 is a view of a protrusion forming step, where (a) is a plan view showing a schematic structure of a mold for protrusion forming, and (B) is a cross-sectional view taken along the arrow B in fig. 6 (a).

Fig. 7 is an enlarged plan view showing a portion a in fig. 5.

Fig. 8 is a plan view showing an electromagnetic steel sheet on which pole teeth are formed.

Fig. 9 is a diagram of a main body forming step, where (a) is a plan view showing a schematic configuration of a mold for main body molding, and (b) is an enlarged plan view of a portion C in fig. 9 (a).

Fig. 10 is a side view showing a processed surface of the stator core plate after the main body portion forming step.

Fig. 11 is a view of the retracting process, where (a) is a view schematically showing a state in which the first tool is moved relative to the second tool, and (b) is a view schematically showing a state in which the first tool is returned to the original position.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated. In addition, the dimensions of the structural members in the drawings do not faithfully represent the actual dimensions of the structural members, the dimensional ratios of the structural members, and the like.

In the following description, a direction parallel to the center axis of the rotor is referred to as an "axial direction", a direction perpendicular to the center axis is referred to as a "radial direction", and a direction along an arc centered on the center axis is referred to as a "circumferential direction". However, the above definition of direction is not intended to limit the orientation of the motor of the present invention when in use.

In the following description, expressions such as "fixed", "connected", and "mounted" (hereinafter, referred to as "fixed" and the like) include not only a case where members are directly fixed to each other and the like, but also a case where members are fixed to each other via other members and the like. That is, in the following description, expressions such as fixation include meanings such as direct and indirect fixation of members to each other.

(Structure of Motor)

Fig. 1 shows a schematic configuration of a motor 1 according to an embodiment of the present invention. The motor 1 includes a rotor 2, a stator 3, a housing 4, and a cover plate 5. 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 the rotor 2 is disposed in the cylindrical stator 3 so as to be rotatable about the central axis P.

The rotor 2 includes a shaft 20, a rotor core 21, and a magnet 22. The rotor 2 is disposed radially inward of the stator 3 and is rotatable with respect to the stator 3.

In the present embodiment, the rotor core 21 is cylindrical and extends along the center axis P. The rotor core 21 is configured by laminating a plurality of electromagnetic steel plates formed into a predetermined shape in a thickness direction.

The shaft 20 extending along the center axis P is fixed to the rotor core 21 in an axially penetrating state. Thereby, the rotor core 21 rotates together with the shaft 20. In the present embodiment, the plurality of magnets 22 are arranged at predetermined intervals in the circumferential direction on the outer peripheral surface of the rotor core 21. In addition, the magnets 22 may be ring magnets connected in the circumferential direction.

The stator 3 is housed in a housing 4. In the present embodiment, the stator 3 is cylindrical, and the rotor 2 is disposed radially inward thereof. That is, the stator 3 is disposed so as to face the rotor 2 in the radial direction. The rotor 2 is disposed radially inward of the stator 3 so as to be rotatable about the central axis P.

The stator 3 includes a stator core 31, a stator coil 33, and a bracket 34. In the present embodiment, the stator core 31 is cylindrical and extends in the axial direction.

As shown in fig. 2, the stator core 31 includes a plurality of pole teeth 31b extending radially inward from a cylindrical yoke 31 a. The stator coil 33 shown in fig. 1 is wound around a bracket 34, and the bracket 34 is made of an insulating resin material or the like attached to the teeth 31b of the stator core 31. The brackets 34 are disposed on both end surfaces of the stator core 31 in the axial direction. The stator core 31 has a plurality of flanges 31c extending radially outward from the cylindrical yoke 31 a. The stator core 31 has a plurality of stator core plates 32 formed in a predetermined shape and stacked in the thickness direction.

As shown in fig. 3, the stator core plate 32 constituting the stator core 31 includes a disk-shaped main body portion 32a and a protruding portion 32d extending radially outward from the main body portion 32 a. The body portion 32a has a yoke portion 32b constituting the yoke 31a of the stator core 31 and a tooth portion 32c constituting the tooth 31b of the stator core 31. The protruding portion 32d constitutes the flange 31c of the stator core 31. The protruding portion 32d is formed by connecting convex shapes extending radially outward from the outer periphery of the main body portion 32a in a smooth curve. The protrusion 32d is formed with a through hole 32 e.

As shown in fig. 2, the housing 4 is cylindrical and extends along the central axis P. In the present embodiment, the housing 4 is cylindrical and has an internal space capable of accommodating the rotor 2 and the stator 3. The housing 4 has a cylindrical side wall 4a and a bottom portion 4b covering one end portion in the axial direction of the side wall 4 a. The opening on the other axial side of the housing 4 is covered with a cover plate 5. The housing 4 and the cover 5 are made of a ferrous material, for example. An inner space is formed inside the case 4 by covering the opening of the case 4 in a bottomed cylindrical shape with the cover plate 5. Although not particularly shown, the cover plate 5 may be fixed to the housing 4 by, for example, bolts or the like, or may be fixed to the housing 4 by press-fitting, bonding or the like. The housing 4 and the cover 5 are not limited to the material containing iron, and may be made of other materials such as aluminum (including aluminum alloy).

(method of manufacturing stator core 31)

Next, a method for manufacturing stator core 31 having the above-described structure will be described with reference to fig. 4 to 9.

Fig. 4 is a flowchart illustrating an example of a method of manufacturing the stator core 31. Fig. 5 is a plan view showing a steel plate 40 in which a part of the protruding portion is formed. Fig. 6 is a view showing a mold for forming a groove including an outer shape of a protrusion. Fig. 7 is an enlarged plan view showing a protrusion formed on a steel plate. Fig. 8 is a plan view showing a steel plate 40 on which the pole teeth are formed. Fig. 9 is a diagram of a mold for forming the body portion.

As shown in fig. 5, in the method of manufacturing the stator core 31, first, a circular center hole 40a is punched out of an electromagnetic steel plate 40 forming a stator core plate. Next, a plurality of rectangular holes 40b are punched, the plurality of rectangular holes 40b surrounding the central hole 40a and including a part of the outer shape of the rotor core plate 23 constituting the rotor core 21. This step is a center hole punching step shown in fig. 4 (step S1). The center of the center hole 40a coincides with the central axis P of the motor 1. Hereinafter, the electromagnetic steel sheet 40 is provided as the steel sheet 40.

The center hole blanking step is performed by press working. Since the center hole punching step is the same as the conventional method for manufacturing stator core 31, detailed description thereof is omitted.

Next, among the methods of manufacturing the stator core 31, a method of manufacturing the stator core plate 32 having the protruding portion 32d extending radially outward from the disk-shaped body portion 32a, a method of manufacturing the stator core plate, and a mold therefor will be described in detail. The method of manufacturing the stator core plate 32 includes a protrusion forming step (step S2) and a body forming step (step S3).

As described above, in the steel plate 40 in which the center hole 40a and the rectangular hole 40b are formed, the plurality of protruding portions 32d are formed on the outer peripheral side of the center hole 40 a. In the step of forming the projecting portion 32d, a predetermined position on the concentric circle of the central hole 40a in the steel plate 40 is punched out to a shape including at least a part of the outer shape X of the projecting portion 32 d. Thereby, at least a part of the outline X of the projection 32d extending radially outward is formed on the steel plate 40. Next, a through hole 32e for attaching the stator core 31 is punched radially inward of the formed protrusion 32 d. The step of forming at least a part of the outer shape X of the protruding portion 32d by punching a part of the steel plate 40 into a shape including at least a part of the outer shape X of the protruding portion 32d is a protruding portion forming step shown in fig. 4 (step S2).

As shown in fig. 6 (a) and 6 (b), the punching process in the protruding portion forming step is performed by press working using a protruding portion punch W1a and a protruding portion die W1b, which are dies for forming the stator core plate 32. In the protrusion forming step, a part of the steel plate 40 disposed on the protrusion die W1b is punched out into a shape including at least a part of the outer shape X of the protrusion 32d by the protrusion punch W1a and the protrusion die W1 b. Since the steel plate 40 is sheared and broken by the protrusion punch W1a, the outer shape X of the protrusion 32d follows the outer shape of the protrusion punch W1 a.

As shown in fig. 6 (b), in the protrusion 32d formed by punching a part of the steel plate 40 disposed on the protrusion die W1b with the protrusion punch W1a, a shear surface Sp1 and a fracture surface Fp1 are formed in this order from the protrusion punch W1a side on the punching surface of the outer edge.

As shown in fig. 7, in the protrusion forming step, a recess 32f is formed in the outer shape portion of the protrusion 32 d. Both circumferential ends of the outer shape portion of the protruding portion 32d of the recess 32f are recessed radially inward. That is, in the protruding portion forming step, the steel plate 40 is punched out in a shape including at least a part of the outer shape portion of the protruding portion 32d, i.e., a shape in which both circumferential end portions of the outer shape portion of the protruding portion 32d are recessed inward in the radial direction. After completion of the punching process, the steel plate 40 is separated from the protrusion punch W1a and the protrusion die W1 b.

Next, as shown in fig. 8, the rotor core plate 23 is punched out around the center axis P of the center hole 40a to form the rotor core plate 23 constituting the rotor core 21 including the center hole 40 a. This step is a rotor core plate punching step shown in fig. 4 (step S4).

After the rotor core plate punching step, a plurality of notches 40c are punched around the central hole 40a to surround the central hole 40a from which the rotor core plate 23 is punched, thereby forming a plurality of pole teeth 32 c. This step is a notch blanking step shown in fig. 4 (step S5).

The rotor core blanking step and the notch blanking step are performed by press working. Since the rotor core plate blanking step and the slot blanking step are the same as those of the conventional method for manufacturing the stator core 31, detailed description thereof is omitted.

Next, as shown in fig. 9 (a), in the steel plate 40 in which the central hole 40a, the plurality of protruding portions 32d, and the plurality of pole teeth portions 32c are formed as described above, the main body portion 32a including the central hole 40a and the plurality of pole teeth portions 32c is formed. In the step of forming the main body portion 32a, the steel plate 40 is punched out into a disk shape in a shape continuous with the outer shape X of the protrusion portion 32 d. Thus, the main body portion 32a including the central hole 40a and the plurality of pole tooth portions 32c and the plurality of protruding portions 32d are formed of a single member. The step of forming the main body portion 32a by punching the steel plate 40 into a shape continuous with the outer shape X of the projecting portion 32d formed in the steel plate 40 is a main body portion forming step shown in fig. 4 (step S6).

The punching in the body portion forming step is performed by press working using a body portion punch W2a and a body portion die W2 b. In the body portion forming step, the steel plate 40 is punched out into an outer shape Y of the outer shape of the stator core plate 32 other than the portion punched out by the protrusion portion die W1b and the protrusion portion punch W1a, in a shape continuing to the outer shape X of the protrusion portion 32d formed in the steel plate 40, by the body portion punch W2a and the body portion die W2 b.

As shown in fig. 9 (b), the steel plate 40 is punched out by the body punch W2a in a state where the end of the body die W2b faces the concave portion 32f formed in the outer shape portion of the protruding portion 32 d. That is, the stator core plate 32 has a recess 32f at a connecting portion between the outer shape X of the protrusion 32d formed in the protrusion forming step and the outer shape Y of the body 32a formed in the body forming step.

In this way, since the recess 32f is formed in advance in the portion where the outline X of the protruding portion 32d and the outline Y of the main body portion 32a are connected in the protruding portion forming step, a joint between the outline X of the protruding portion 32d and the outline Y of the main body portion 32a is not formed in the stator core plate 32. Therefore, the stator core plate 32 can be formed in two steps, i.e., a protruding portion forming step of punching out the shape X including the outer shape of the protruding portion 32d and a main body portion forming step of punching out only the shape Y of the main body portion 32 a. This can prevent plastic deformation of the protruding portion 32d during the manufacturing process of the stator core plate 32.

In the body portion forming step, the portion of the stator core plate 32 punched out by the body portion punch W2a other than the protruding portion 32d is pressed down in contact with the body portion die W2 b. That is, the body portion die W2b and the body portion punch W2a do not contact the protruding portion 32d formed in the protruding portion forming step at the steel plate 40.

In this way, in the body portion forming step, since the portions other than the protruding portion 32d formed by the protruding portion punch W1a and the protruding portion die W1b are punched out by the body portion punch W2a and the body portion die W2b, punching stress due to punching out of the body portion 32a and external force due to contact with a die for punching out the body portion 32a do not occur in the protruding portion 32 d. This can prevent plastic deformation of the protruding portion 32d during the manufacturing process of the stator core plate 32.

As shown in fig. 10, since the steel sheet 40 is sheared and broken by the main body portion die W2b by the pressing of the main body portion punch W2a, the main body portion 32a follows the shape of the main body portion punch W2 b. Thus, in the body portion 32a formed by punching out a part of the steel sheet 40 disposed on the body portion punch W2b by the body portion punch W2a, the shear surface Sp2 and the fracture surface Fp2 are formed in this order from the body portion die W2b side on the punched surface of the outer edge.

In the stator core plate 32 formed as described above, the arrangement of the fracture surface Fp1 and the shear surface Sp1 in the thickness direction in at least a part of the outer edge of the protrusion 32d is different from the arrangement of the fracture surface Fp2 and the shear surface Sp2 at the outer edge of the main body portion 32a in the thickness direction. That is, since the stator core plate 32 is formed by dividing the stator core plate 32 into two steps of the step of punching out the shape X including the outer shape of the protruding portion 32d and the step of punching out the shape of the body portion 32a, punching stress due to punching out of the body portion 32a and external force due to contact with the body portion punch Wa2 and the body portion die W2b that punch out the body portion 32a do not occur in the protruding portion 32 d. This can prevent plastic deformation of the protruding portion 32d of the stator core plate 32.

As described above, the method of manufacturing the stator core plate 32 having the protruding portion 32d extending radially outward from the disk-shaped body portion 32a includes the protruding portion forming step of punching out a part of the steel plate 40 in a shape including at least a part of the outer shape X of the protruding portion 32d to form at least a part of the outer shape X of the protruding portion 32d, and the body portion forming step of punching out the steel plate 40 in a shape including the outer shape Y continuous with the outer shape X of the protruding portion 32d formed in the steel plate 40 to form the body portion 32 a.

With the above configuration, since the protruding portion 32d is punched out in the protruding portion forming step that is a step preceding the main portion forming step of forming the main portion 32a, punching stress due to punching out of the main portion 32a and external force due to contact with a die for punching out the main portion 32a do not occur in the protruding portion 32 d. This prevents plastic deformation of the protruding portion 32d without forming a space in the main body portion 32a for reducing the magnetic flux density.

Then, the stator core plate 32 having the plurality of projections 32d and the plurality of pole teeth 32c formed by the method of manufacturing the stator core plate 32 is sequentially formed by punching, and laminated in the thickness direction. The laminated stator core plates 32 are caulked or welded to obtain the stator core 31 shown in fig. 2. In the stator core plate 32 formed by the method of manufacturing the stator core plate 32, plastic deformation of the protruding portion 32d is prevented, and therefore, the stator core 31 in which the stator core plates 32 are laminated without a gap in the thickness direction can be obtained. This step is a laminating step shown in fig. 4 (step S7).

(other embodiments)

The embodiments of the present invention have been described above, but the above embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above embodiment, and the above embodiment can be appropriately modified and implemented without departing from the scope of the present invention.

In the above embodiment, in the main body portion forming step, the stator core plates 32 formed by punching are laminated to obtain the stator core 31. However, the stator core plate 32 may be formed by a so-called retraction process in which the punched portion is returned to the original position after punching in the thickness direction in accordance with the shape of the stator core plate 32, in addition to the punching process.

As shown in fig. 11, in the steel sheet 40, the retracting process is performed using a first tool W3 and a second tool W4, wherein the first tool W3 has a pair of upper and lower tools sandwiched in the thickness direction along the outer shape Y of the body portion 32a from the inside of the body portion 32a, and the second tool W4 has a pair of upper and lower tools sandwiched in the thickness direction along the outer shape Y of the body portion 32a from the outside of the body portion 32 a. The first tool W3 is movable relative to the second tool W4 in the thickness direction of the steel plate 40. In the present embodiment, the first tool W3 has the same shape as the stator core plate 32. The second tool W1 has a shape that sandwiches the outer shape of the stator core plate 32 except for the portion punched out by the protrusion die W1b and the punch.

As shown in fig. 11 (a), by moving the first tool W3 to one side in the thickness direction of the steel plate 40 with respect to the second tool W4, the steel plate 40 is subjected to shearing at the boundary between the portion sandwiched by the first tool W3 and the portion sandwiched by the second tool W4. The movement distance of the first tool W3 with respect to the second tool W4 may be a movement distance for separating the steel plate 40 or a movement distance for not separating the steel plate 40.

Then, as shown in fig. 11 (b), the first tool W3 is moved to the other side in the thickness direction of the steel sheet 40 with respect to the second tool W4, whereby the first tool W3 is returned to the original position. Thereby, at the boundary, the portion of the steel plate 40 sandwiched by the first tool W3 is embedded in the portion sandwiched by the second tool W4. The main body portion 32a is frictionally held by the steel plate 40 around the main body portion 32a that has not been extruded by the retraction process.

Here, the step of forming the main body portion 32a by the retraction processing as described above corresponds to the retraction step.

As described above, in the main body portion forming step of the method of manufacturing the stator core plate 32, the main body portion 32a may be formed by a retraction process in addition to the punching process. By molding the stator core plate 32 by the retraction process, the occurrence of residual stress and residual strain due to the process at the body portion 32a is suppressed. As described above, in the method of manufacturing the stator core plate 32, regardless of the method of processing the body portion 32a, punching stress due to punching of the body portion 32a and external force due to contact with a die for punching the body portion 32a do not occur in the protruding portion 32 d. This can prevent plastic deformation of the protruding portion 32d during the manufacturing process of the stator core plate 32.

In the above embodiments, the motor is a so-called permanent magnet motor. In a permanent magnet motor, the rotor 2 has a magnet 22. However, the motor 1 may be a motor without the magnet 22, such as an induction motor, a reluctance motor, a switched reluctance motor, or a wound field motor.

In the above embodiment, the method for manufacturing the stator core 31 of the motor 1 is described, but the method is not limited thereto, and the method for manufacturing the above embodiment can be applied to the case of manufacturing a structure having a laminated body of the steel plates 40.

Industrial applicability of the invention

The present invention can be applied to a method for manufacturing a stator core plate 32 having a protrusion 32d extending radially outward from a disk-shaped body portion 32 a.

Description of the symbols

1, a motor; 2, a rotor; 3, a stator; 31a stator core; 32 stator core plates; 32a main body portion; a 32b yoke portion; a 32 c-pole tooth portion; a 32d projection; a 32e through hole; a 32f recess; 40 steel plate.