WO2023181611A1

WO2023181611A1 - Coil manufacturing method and coil manufacturing device

Info

Publication number: WO2023181611A1
Application number: PCT/JP2023/001557
Authority: WO
Inventors: 充博井芹; 英之谷口; 茂樹和田; 裕規坂口
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-03-24
Filing date: 2023-01-19
Publication date: 2023-09-28

Abstract

Provided is a coil manufacturing method for manufacturing a coil by processing a rectangular conductor that has: a first main surface; a second main surface positioned opposite to the first main surface; a first connecting surface connecting the first main surface and the second main surface; and a second connecting surface that connects the first main surface and the second main surface and is positioned opposite to the first connecting surface. The coil manufacturing method comprises a step for processing a processing portion of the rectangular conductor so as to be thinner than other portions thereof, the processing portion being defined on the basis of a neutral line for bending of the rectangular conductor, and a step for subjecting the rectangular conductor to a bending process such that the first connecting surface is on the inside of the rectangular conductor.

Description

Coil manufacturing method and coil manufacturing device

The present disclosure relates to a coil manufacturing method and a coil manufacturing device.

Motors used in home appliances, automobiles, etc. use coils formed by spirally winding rectangular conductors. For example, Patent Document 1 discloses a coil manufacturing method for forming a spirally wound motor coil.

Japanese Patent Application Publication No. 2008-178199

In such a coil manufacturing method, variations may occur in the thickness of the rectangular conductor due to bending.

Therefore, an object of the present disclosure is to provide a coil manufacturing method and a coil manufacturing apparatus that can suppress variations in the thickness of a rectangular conductor due to bending.

The coil manufacturing method according to the present disclosure includes a first main surface, a second main surface located opposite to the first main surface, and a first connection surface connecting the first main surface and the second main surface. , a coil manufacturing method for manufacturing a coil by processing a rectangular conductor having a second connection surface that connects the first main surface and the second main surface and is located opposite to the first connection surface. The coil manufacturing method includes the steps of processing the processed portion such that the processed portion defined based on the neutral line of bending of the rectangular conductor is thinner than other portions other than the processed portion; The method includes the step of bending the rectangular conductor so that the connection surface is inside the rectangular conductor.

The coil manufacturing apparatus according to the present disclosure includes a first main surface, a second main surface located opposite to the first main surface, and a first connection surface connecting the first main surface and the second main surface. , a coil manufacturing apparatus for manufacturing a coil by processing a rectangular conductor having a second connection surface that connects the first main surface and the second main surface and is located opposite to the first connection surface. The coil manufacturing device includes a processing device that processes the processed portion such that the processed portion defined based on the neutral line of bending of the rectangular conductor is thinner than other portions other than the processed portion; and a bending device that bends the rectangular conductor so that one connection surface is inside the rectangular conductor.

According to the coil manufacturing method and coil manufacturing apparatus according to the present disclosure, it is possible to provide a coil manufacturing method and a coil manufacturing apparatus that can suppress variations in the thickness of a rectangular conductor due to bending.

It is a part of sectional view of the stator core of a motor. 2 is a perspective view of the coil shown in FIG. 1. FIG. 3 is a perspective view of a rectangular conductor that constitutes the coil shown in FIG. 2. FIG. 3 is a block diagram for explaining the configuration of a coil manufacturing apparatus that manufactures the coil shown in FIG. 2. FIG. FIG. 2 is a flow diagram of a manufacturing process related to a coil manufacturing method according to the present disclosure. FIG. 3 is a side view showing one step of the coil manufacturing method according to the present disclosure. FIG. 3 is a side view showing one step of the coil manufacturing method according to the present disclosure. FIG. 3 is a side view showing one step of the coil manufacturing method according to the present disclosure. FIG. 3 is a plan view showing one step of the coil manufacturing method according to the present disclosure. FIG. 3 is a perspective view showing one step of the coil manufacturing method according to the present disclosure. FIG. 3 is a plan view of a rectangular conductor illustrating a neutral line of bending. FIG. 3 is a plan view of a portion defined based on a bending neutral line of a rectangular conductor. It is a perspective view of a processed part. FIG. 3 is a plan view of a processed portion. FIG. 7 is a plan view showing another shape of the processed portion. FIG. 7 is a plan view showing another shape of the processed portion. FIG. 7 is a plan view showing another shape of the processed portion. FIG. 7 is a plan view showing another shape of the processed portion. 7 is a perspective view of a processed portion according to Modification 1. FIG. FIG. 7 is a perspective view of a processed portion according to Modification 2; FIG. 7 is a perspective view of a processed portion according to Modification 3. FIG. 7 is a perspective view of a processed portion according to modification example 4.

(The circumstances that led to this disclosure)
With the declining birthrate and aging population, load reduction devices and/or fully automatic devices that incorporate AI to replace manual labor are rapidly developing. Furthermore, from an environmental point of view, electric vehicles and hybrid vehicles are increasingly being distributed. Many types of motors are employed in these devices and/or machines, and the demand for motors is rapidly expanding. Additionally, efforts are being made to further increase the output and efficiency of motors.

Motors used in automobiles have multiple cores, which are laminated iron cores made of laminated thin plates such as silicon steel plates, arranged around the circumference, and a conductor, which is a path for current, is wrapped around each core. Equipped with parts. This conductor functions as a coil, and when current is passed through the coil, the motor rotates. The rotational efficiency of the motor improves as the current flowing through the coil increases. It is known that increasing the current flowing through a coil can be achieved by increasing the ratio of the total cross-sectional area of the conductor (space factor) in the cross-sectional area of the coil cut along a plane perpendicular to the direction of the current flowing through the conductor. ing.

Therefore, in recent years, in order to increase the space factor of this conductor, a method has been adopted in which a conductor with a rectangular cross-section (rectangular conductor) is bent and wound around the core instead of a conductor with a circular cross-section. Further, when the rectangular conductor is spirally wound around the core, the space factor of the conductor can be increased by reducing the gap between two adjacent layers of the laminated layers formed by the rectangular conductor.

Here, an example of a method for bending such a rectangular conductor will be explained. A flat conductor with a rectangular cross section is bent in the longitudinal direction of the rectangular cross section (width direction of the flat conductor). That is, the rectangular conductor is bent with the side in the short direction of the cross section of the rectangular conductor set as the inside (inner diameter). This can also be said to bend the rectangular conductor in a direction that is difficult to bend. This type of bending is called edgewise bending.

In the method of manufacturing a coil by bending a rectangular conductor by edgewise bending, first edgewise bending is performed at three locations on the rectangular conductor. Thereafter, the rectangular conductor is shifted in the short direction of the rectangular cross section (thickness direction of the rectangular conductor), and edgewise bending is performed at four locations. This process is repeated multiple times to form a three-dimensional spiral shape while winding the rectangular conductor around the core.

The rectangular conductor after edgewise bending includes two straight parts and a bent part located between the two straight parts. The bent portion is a portion bent by edgewise bending. The two straight sections are the sections that are not bent by edgewise bending. The length of the straight portion along the length of the rectangular conductor after bending does not change from the length of the straight portion along the length of the rectangular conductor before bending. In other words, the length of one straight part after bending is A', the length of the other straight part is C', the length of one straight part before bending is A, and the straight part of the other side is C'. If the length of is C, then A=A' and C=C'.

On the other hand, in the bent portion when bent, compressive stress acts inside the rectangular conductor on the inner diameter side, and tensile stress acts on the outer diameter side, bordering on a certain circular arc portion. The material contracts in areas where this compressive stress acts, and stretches in areas where tensile stress acts. In addition, the boundary between the area where compression acts and the area where tension acts is an arc-shaped area that neither shrinks nor expands, and this area is called the neutral line of bending (hereinafter also referred to simply as the ``neutral line''). call). If the length of the neutral line along the length of the rectangular conductor after bending is B', and the length of the portion corresponding to the neutral line before bending is B, then B'=B. The length B of the portion corresponding to the neutral line before bending is sometimes called a bending allowance.

When edgewise bending is performed, compressive stress acts on the inner part of the neutral line, making the material thick and bulging, while the outer part becomes thinner, as tensile stress acts on it. Compressive stress acts on the inner part of the neutral line, and the strength of the compressive stress increases as you go inward from the neutral line. Therefore, the thickness of the material increases as it goes inward from the neutral line. Furthermore, the compressive stress in the length direction of the conductor increases as it approaches the center of the bent portion.

Similarly, tensile stress acts on the parts outside the neutral line, and the strength of the tensile stress increases as you move outward from the neutral line. Therefore, the thickness of the material decreases as it goes outward from the neutral line. Further, the tensile stress in the length direction of the conductor increases as it approaches the center of the bent portion.

On the other hand, since neither compressive stress nor tensile stress acts on the neutral line, no change in material thickness occurs. In this way, when edgewise bending is performed, the thickness of the bent portion differs along the width direction.

In this way, when edgewise bending is performed, the thickness of the portion inside the neutral line is thicker than the thickness of the portion outside the neutral line, so there is a problem that the thickness of the bent portion of the rectangular conductor varies. For this reason, when a rectangular conductor is spirally wound, a gap is generated between two layers adjacent to each other in the lamination direction, and the space factor of the rectangular conductor is reduced. As a result, it may become difficult to increase the amount of current flowing through the coil.

Therefore, in order to solve this problem, the inventors have made extensive studies, and as a result, the coil manufacturing method of the present disclosure involves processing the portion defined based on the neutral line into a thinner part and bending the thinner processed part. and a coil manufacturing device.

A coil manufacturing method according to an aspect of the present disclosure includes a first main surface, a second main surface located opposite to the first main surface, and a first connection connecting the first main surface and the second main surface. and a second connection surface connecting the first main surface and the second main surface and located opposite to the first connection surface, based on the neutral line of bending of the rectangular conductor. and bending the rectangular conductor in the thinner processed portion with the first connection surface facing inside.

With such a coil manufacturing method, variations in the thickness of the rectangular conductor due to bending can be suppressed.

In the coil manufacturing method, the width of the processed portion along the length direction of the rectangular conductor may increase from near the neutral line toward the first connection surface.

With such a coil manufacturing method, variations in the thickness of the rectangular conductor due to bending can be further suppressed.

In the coil manufacturing method, the thickness of the processed portion may become thinner as it approaches the first connection surface from near the neutral line.

In the coil manufacturing method, the thinning step may include thinning the rectangular conductor from both the first main surface and the second main surface.

In the coil manufacturing method, the thickness of the processed portion may become thinner toward the center of the processed portion in the length direction of the rectangular conductor.

In the coil manufacturing method, the shape of the processed portion when viewed from the thickness direction of the rectangular conductor may be a shape having an apex located near the neutral line.

In the coil manufacturing method, the shape of the processed portion when viewed from the thickness direction of the rectangular conductor may be triangular.

With such a coil manufacturing method, it is easy to form the processed portion.

The coil manufacturing method may further include the step of fixing a portion located around a portion defined based on a neutral line of bending of the rectangular conductor from a thickness direction of the rectangular conductor.

In the coil manufacturing method, the thinning step may include pressing a portion defined based on a neutral line of bending of the rectangular conductor.

With such a coil manufacturing method, the step of thinning the coil can be easily carried out.

A coil manufacturing device according to an aspect of the present disclosure includes a first main surface, a second main surface located opposite to the first main surface, and a first connection surface that connects the first main surface and the second main surface. and a second connection surface that connects the first main surface and the second main surface and is located opposite to the first connection surface, based on the neutral line of bending of the rectangular conductor. The present invention includes a processing device that processes a defined portion to be thinner than other portions, and a bending device that bends the rectangular conductor so that the thinner processing portion faces the first connection surface inside.

With such a configuration, variations in the thickness of the rectangular conductor due to bending can be suppressed.

In the coil manufacturing apparatus, the width of the processed portion along the length direction of the rectangular conductor may increase from near the neutral line toward the first connection surface.

With such a configuration, variations in the thickness of the rectangular conductor due to bending can be further suppressed.

In the coil manufacturing apparatus, the thickness of the processed portion may become thinner as it approaches the first connection surface from near the neutral line.

In the coil manufacturing device, the processing device may process the rectangular conductor thin from both the first main surface and the second main surface.

In the coil manufacturing apparatus, the thickness of the processed portion may become thinner toward the center of the processed portion in the length direction of the rectangular conductor.

In the coil manufacturing apparatus, the shape of the processed portion when viewed from the thickness direction of the rectangular conductor may be a shape having an apex located near the neutral line.

In the coil manufacturing apparatus, the shape of the processed portion when viewed from the thickness direction of the rectangular conductor may be triangular.

With such a configuration, it is easy to form the processed portion.

The coil manufacturing apparatus may further include a fixing device that fixes a portion located around a portion defined based on a neutral line of bending of the rectangular conductor from a thickness direction of the rectangular conductor.

In the coil manufacturing device, the processing device may press-process a portion defined based on a neutral line of bending of the rectangular conductor.

With such a configuration, the portion defined based on the neutral line of bending of the rectangular conductor can be easily processed to be thin.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Furthermore, in each figure, each element is exaggerated for ease of explanation.

As used herein, terms such as "first", "second", etc. are used for descriptive purposes only and are not to be understood as expressing or implying relative importance or ranking of technical features. Shouldn't. Features defined as "first" and "second" are expressly or implied to include one or more such features. In addition, in the attached drawings, the X0, Y0, and Z0 directions in the drawing indicate the width direction, depth direction, and thickness direction of the stator core, respectively, and the X, Y, and Z directions in the drawing respectively indicate the length of the rectangular conductor. The length direction, width direction, and thickness direction are shown.

<Embodiment>
(coil)
FIG. 1 is a partial cross-sectional view of a stator core of a motor. FIG. 2 is a perspective view of the coil shown in FIG. 1. FIG. 3 is a perspective view of a rectangular conductor that constitutes the coil shown in FIG. 2.

The coil 1 according to the present disclosure is, for example, arranged to be wound around the stator core 2 of a motor. The stator core 2 is, for example, an annular member, and includes a plurality of teeth 3 that extend radially when viewed from the thickness direction Z0 of the stator core 2. FIG. 1 shows one tooth 3, and as shown in FIG. 1, the coil 1 is arranged to be wound around each tooth. The teeth 3 are columnar members extending in the thickness direction Z0 of the stator core 2. The shape of the teeth 3 viewed from the thickness direction Z0 of the stator core 2 is, for example, a substantially rectangular shape. The stator core 2 is formed by laminating thin plates such as silicon steel plates, for example. For example, the coil 1 is arranged to be wound around the teeth 3 in accordance with the outer shape of the teeth 3. The motor rotates by passing current through the coil 1.

As shown in FIG. 2, the coil 1 is composed of a wound rectangular conductor 10. As shown in FIG. 3, the rectangular conductor 10 is a conductive wire that includes one end 15 and the other end 16 located opposite to the one end 15 in the length direction X of the rectangular conductor. As shown in FIG. 3, when the rectangular conductor 10 is not bent, the length direction X is a direction extending between one end 15 and the other end 16 of the rectangular conductor 10, and is a direction represented by a straight line. be.

As shown in FIG. 3, the rectangular conductor 10 has a first main surface 11, a second main surface 12, a first connection surface 13, and a second connection surface 14. The first main surface 11, the second main surface 12, the first connection surface 13, and the second connection surface 14 each extend between one end 15 and the other end 16. The second main surface 12 is a surface located opposite to the first main surface 11 in the thickness direction Z. The first connection surface 13 is a surface located opposite to the second connection surface 14 in the width direction Y. The first connection surface 13 and the second connection surface 14 are surfaces that connect the first main surface 11 and the second main surface 12, respectively. The rectangular conductor 10 has a rectangular cross section perpendicular to the length direction X.

The distance between the first connection surface 13 and the second connection surface 14 of the rectangular conductor 10, that is, the width W of the rectangular conductor 10 is, for example, 5 mm or more and 10 mm or less. The distance between the first main surface 11 and the second main surface 12 of the rectangular conductor 10, that is, the thickness T0 of the rectangular conductor 10 is, for example, 1 mm or more and 2 mm or less.

The rectangular conductor 10 includes, for example, a conductive member and an insulating member covering the surface of the conductive member. The conductive member is exposed from the insulating member at one end 15 and the other end 16 of the rectangular conductor 10. The conductive member is, for example, copper. The insulating member is, for example, a resin such as enamel, polyimide, amideimide, epoxy, melamine, or phenol.

As shown in FIG. 2, the coil 1 is formed by spirally winding the rectangular conductor 10 with the first connection surface 13 facing inside. Further, in the coil 1, rectangular conductors 10 are laminated in the thickness direction Z. As shown in FIG. 1, in two adjacent layers among the laminated layers, the first main surface 11 of the rectangular conductor 10 forming one layer and the second main surface of the rectangular conductor 10 forming the other layer. 12 are in contact with each other.

<Coil manufacturing equipment>
Next, the configuration of a coil manufacturing apparatus for manufacturing the coil 1 will be described using FIG. 4. FIG. 4 is a block diagram for explaining the configuration of a coil manufacturing apparatus that manufactures the coil shown in FIG. 2. As shown in FIG. 4, the coil manufacturing device 40 includes a processing device 60, a bending device 70, and a control device 50.

(Processing equipment)
The processing device 60 processes a portion (processed portion) of the rectangular conductor 10 defined based on the neutral line of bending of the rectangular conductor 10 to be thinner than other portions.

In this embodiment, the processing device 60 is, for example, a press processing device. The processing device 60 is, for example, a press machine. When the processing device 60 is a press processing device, the processing device 60 includes, for example, a first tool 61 and a second tool 62. The first tool 61 and the second tool 62 are, for example, punches.

The first tool 61 and the second tool 62 are arranged coaxially, for example. Specifically, the first tool 61 and the second tool 62 are arranged on an axis extending in the vertical direction of the processing device 60. The first tool 61 and the second tool 62 can move in the vertical direction of the processing device 60 along the axis. The processing device 60 presses the flat conductor 10 by moving the first tool 61 and the second tool 62 in the vertical direction.

The first tool 61 and the second tool 62 are, for example, columnar members with a circular, triangular, or rectangular cross-sectional shape. The first tool 61 and the second tool 62 are, for example, removable from the processing device 60. The shapes of the first tool 61 and the second tool 62 attached to the processing device 60 are appropriately selected depending on the shape of the portion defined based on the neutral line of bending of the rectangular conductor 10, which will be described later. The material of the first tool 61 and the second tool 62 is, for example, carbon tool steel, special tool steel, die steel, high speed steel, cemented carbide, or the like.

The processing device 60 may further include a fixing device 63. The fixing device 63 fixes a portion of the rectangular conductor 10 located around a portion defined based on the neutral line of bending of the rectangular conductor 10 in the thickness direction Z. The fixing device 63 fixes the rectangular conductor 10 with the first main surface 11 and the second main surface 12 of the rectangular conductor 10 interposed therebetween. In this embodiment, the fixing device 63 is made of a mold. For example, the fixing device 63 is a die to which a first tool 61 and a second tool 62 are attached.

Additionally, the processing device may be a cutting device. The cutting device is, for example, a milling machine. When the processing device is a cutting device, the processing device includes, for example, a cutting tool such as an end mill. The processing device cuts a portion 20 defined based on the neutral line L using a cutting tool.

(Bending processing equipment)
The bending device 70 bends the rectangular conductor 10 so that the first connection surface 13 faces inside the thinly processed portion.

(Control device)
The control device 50 controls the fixing device 63, the processing device 60, and the bending device 70. Control device 50 includes a data input section and a processor.

The data input unit is, for example, an interface such as a touch panel or a keyboard. Data such as fixing conditions, processing conditions for thinning, processing conditions for bending, etc. are input to the data input section. The fixing conditions include, for example, the fixing position and fixing pressure. The conditions for thinning are, for example, the range of the portion defined based on the neutral line of bending of the rectangular conductor 10, the processing speed, etc. Furthermore, when the processing device 60 is a pressing device, the processing conditions include, for example, pressing speed, pressing pressure, and the like. The processing conditions for bending include, for example, the bending radius and bending speed.

The processor controls the fixing device 63, the processing device 60, and the bending device 70 based on the data input to the data input section.

The processor is a CPU (Central Processing Unit) as a control center, ROM (READ ONLY MEMORY), which remembers programs and control data for the operation of the CPU, and RAM (RANDOM ACCE (RANDOM ACCE) (RANDOM ACCE). SS Memory) etc. are provided. Processors also include microcomputers, MPUs (Micro-Processing Units), GPUs (Graphics Processing Units), DSPs (Digital Signal Processors), and FPGAs (Field Programming Units). Even if there are electronic components such as rammable Gate Array), ASIC (Application Specific Integrated Circuit), etc. good.

Note that the control device 50 may be provided as a separate device from the coil manufacturing device 40. Further, the control device 50 may be provided in each of the fixing device 63, the processing device 60, and the bending device 70.

<Coil manufacturing method>
FIG. 5 is a flow diagram of a manufacturing process according to a coil manufacturing method according to the present disclosure. 6A to 6C are side views showing one step of the coil manufacturing method according to the present disclosure. FIG. 6D is a plan view showing one step of the coil manufacturing method according to the present disclosure. FIG. 6E is a perspective view showing one step of the coil manufacturing method according to the present disclosure. A coil manufacturing method according to an embodiment will be described with reference to FIG. 5 and FIGS. 6A to 6E. As shown in FIG. 5, the coil manufacturing method according to the present disclosure includes a fixing step S1, a thinning step S2, and a bending step S3.

(Fixing step)
As shown in FIG. 6A, in the fixing step S1, a portion 24 located around a portion 20 defined based on a neutral line of bending of the rectangular conductor 10, which will be described later, is fixed from the thickness direction Z. The portion 24 is fixed, for example, from both the first main surface 11 and the second main surface 12 of the rectangular conductor 10. That is, in the fixing step S1, the portion 24 located around the portion 20 defined based on the neutral line of bending of the rectangular conductor 10 is fixed from both the first principal surface 11 and the second principal surface 12 of the rectangular conductor 10. By pressing, the rectangular conductor 10 is held. In addition, below, the neutral line of bending of the rectangular conductor 10 is also simply called a "neutral line." Furthermore, the portion 24 located around the portion 20 defined based on the neutral line is also referred to as the "surrounding portion 24." The peripheral portion 24 is fixed by a fixing device 63 of the processing device 60.

(Step for thinning)
As shown in FIG. 6B, in the thinning step S2, a portion 20 of the rectangular conductor 10 defined based on the neutral line L of bending of the rectangular conductor 10 is processed to be thinner than other portions. Step S2 of processing thinly is performed by the processing device 60. Further, in step S2 of thinning, the rectangular conductor 10 is thinned from both the first main surface 11 and the second main surface 12.

In this embodiment, the step S2 of thinning is a step of pressing. Pressing is a process in which the rectangular conductor 10 is depressed using a punch or the like. In this embodiment, the step S2 of thinning is performed by the processing device 60, which is a press processing device.

The processing device 60 brings the first tool 61 into contact with the first main surface 11, the second tool 62 into contact with the second main surface 12, and sandwiches the rectangular conductor 10 between the first tool 61 and the second tool 62 to thin the rectangular conductor 10. Process.

When the portion 20 defined based on the neutral line L is thinned, a processed portion 30 is formed as shown in FIG. 6C. The processed portion 30 is a portion of the rectangular conductor 10 processed to be thinner. Further, the processed portion 30 is a concave portion of the rectangular conductor 10.

Here, in order to explain the detailed shape of the portion 20 defined based on the neutral line L and the detailed shape of the processed portion 30, the neutral line L will be explained with reference to FIG. 7. FIG. 7 is a plan view of a rectangular conductor illustrating the neutral line of bending. In FIG. 7, the length direction Xa of the bent portion is the direction in which the rectangular conductor 10 extends after step S3 of bending, which will be described later. Therefore, the length direction Xa of the portion bent in step S3 of bending is a direction represented by a curved line, as shown in FIG.

(neutral line)
First, when the rectangular conductor 10 is bent in step S3 of bending, which will be described later, a bent portion 90 is formed. In other words, the bent portion 90 is a portion bent in step S3 of bending. The bent portion 90 includes one end 90a and the other end 90b in the length direction Xa of the bent portion.

The neutral line L is a line indicating a portion of the bent portion 90 where the rectangular conductor 10 is neither compressed nor expanded in the length direction. That is, the neutral line L is a portion of the bent portion 90 where the length in the length direction X before bending step S3 is equal to the length Xa of the bent portion after bending step S3. This is the line shown.

As shown in FIG. 7, when the position of the neutral line L is expressed by the distance K between the first connection surface 13 and the neutral line L when the rectangular conductor 10 is viewed from the thickness direction Z, the distance K is: It can be calculated using the following equation 1 using the length of the rectangular conductor 10 in the width direction Y, that is, the width W of the rectangular conductor 10, and a coefficient λ.
(Formula 1)
K=W×λ
The coefficient λ is determined based on the range of the ratio R/W of the bending radius R and the width W of the rectangular conductor 10, where R is the bending radius of the rectangular conductor 10 in step S3 of bending. The relationship between the coefficient λ and the range of the ratio R/W has the relationship shown in Table 1 below.

From Table 1, for example, when the bending radius R becomes five times or more the width W of the rectangular conductor 10, the distance K becomes half the width W of the rectangular conductor 10. That is, the position of the neutral line L is the center in the width direction Y.

(The part defined based on the bending neutral line of the rectangular conductor)
FIG. 8 is a plan view of a portion defined based on the bending neutral line of the rectangular conductor. As shown in FIG. 8, the shape of the portion 20 defined based on the neutral line L when viewed from the thickness direction Z is a shape having an apex located near the neutral line L. In this specification, the vicinity of the neutral line L is a range shifted from the neutral line L along the width direction Y by 10% or less (width ΔW) of the width W of the rectangular conductor 10. Specifically, the vicinity of the neutral line L is a position shifted from the neutral line L to the first connection surface 13 side by a width ΔW along the width direction Y, and a position shifted from the neutral line L by a width ΔW along the width direction Y. 2 refers to the range between the position shifted toward the connecting surface 14 side.

Further, the width X1 along the length direction X of the portion 20 defined based on the neutral line L becomes wider as it approaches the first connection surface 13 from the vicinity of the neutral line L.

As shown in FIG. 8, in this embodiment, the shape of the portion 20 defined based on the neutral line L is triangular when viewed from the thickness direction Z. The triangular shape has, for example, one vertex (first vertex 21) near the neutral line L and two other vertices (second vertex 22 and third vertex 23) on the first connection surface 13. . For example, when the triangular shape is viewed from the thickness direction Z, the length of the side connecting the first apex 21 and the second apex 22 is equal to the length of the side connecting the first apex 21 and the third apex 23. It is an isosceles triangle.

The second vertex 22 is located near one end 90a of the bent portion 90 when viewed from the thickness direction Z. The third vertex 23 is located near the other end 90b of the bent portion 90 when viewed from the thickness direction Z. In this specification, the vicinity of one end 90a refers to a region that is 10% or less (length ΔX) of the length X3 between one end 90a and the other end 90b, and from one end 90a to This is the range shifted along the length direction X. The direction from one end 90a to the other end 90b is the +X direction, the direction from the other end 90b to the one end 90a is the -X direction, and the vicinity of the one end 90a is specifically defined. The result is shown below. The vicinity of one end 90a is defined as the area between the position shifted from one end 90a by a length ΔX in the +X direction and the position shifted from one end 90a by a length ΔX in the -X direction. range. Similarly, in this specification, the vicinity of the other end 90b is a range shifted in the length direction X by a length ΔX from the other end 90b. Specifically, the vicinity of the other end 90b refers to a position shifted by a length ΔX in the +X direction from the other end 90b, and a position shifted by a length ΔX in the −X direction from the other end 90b. The range is between .

(processing part)
FIG. 9A is a perspective view of the processed portion, and FIG. 9B is a plan view of the processed portion. The processed portion 30 is formed, for example, by pressing the portion 20 defined based on the neutral line L from the thickness direction Z. As shown in FIGS. 8 and 9B, the shape of the processed portion 30 viewed from the thickness direction Z is approximately the same shape as the portion 20 defined based on the neutral line L when viewed from the thickness direction Z. Therefore, the shape of the processed portion 30 viewed from the thickness direction Z is a shape having an apex located near the neutral line L, as shown in FIG. 9B. Furthermore, the width X2 of the processed portion 30 along the length direction X when viewed from the thickness direction Z increases as it approaches the first connection surface 13.

As shown in FIG. 9B, in this embodiment, the shape of the processed portion 30 when viewed from the thickness direction Z is triangular. The triangular shape has, for example, one vertex (first vertex 31) near the neutral line L and two other vertices (second vertex 32 and third vertex 33) on the first connection surface 13. It has a triangular shape. For example, when the triangular shape is viewed from the thickness direction Z, the length of the side connecting the first apex 31 and the second apex 32 is the same as the length of the side connecting the first apex 31 and the third apex 33. They are equal isosceles triangles.

As described above, the first vertex 31 is located near the neutral line L. Specifically, the first vertex 31 is located on the neutral line L, for example, as shown in FIG. 9B.

Further, as shown in FIG. 10A, the first vertex 31a is located between the neutral line L and a position L2 shifted from the neutral line L by a width ΔW toward the second connection surface 14 side along the width direction Y. You may do so.

Further, as shown in FIG. 10B, the first vertex 31b is located between the neutral line L and a position L1 shifted from the neutral line L by a width ΔW toward the first connection surface 13 side along the width direction Y. You may do so. Note that the width ΔW is 10% or less of the width W of the rectangular conductor 10.

The second vertex 32 is located near one end 90a of the bent portion 90 when viewed from the thickness direction Z. The third vertex 33 is located near the other end 90b of the bent portion 90 when viewed from the thickness direction Z. Specifically, as shown in FIG. 10C, the second vertex 32 is located between the one end 90a and a position shifted by a length ΔX in the −X direction from the one end 90a. It's okay. Similarly, the third vertex 33 may be located between the other end 90b and a position shifted by a length ΔX in the +X direction from the other end 90b.

Further, as shown in FIG. 10D, the second vertex 32 may be located between the one end 90a and a position shifted by a length ΔX in the +X direction from the one end 90a. Similarly, the third vertex 33 may be located between the other end 90b and a position shifted by a length ΔX in the −X direction from the other end 90b. Note that the length ΔX is 10% or less of the length X3 between one end 90a and the other end 90b.

As shown in FIG. 9A, the processed portion 30 includes a first processed surface 30a and a second processed surface 30b. The first processed surface 30a and the second processed surface 30b are, for example, flat surfaces. The distance between the first processed surface 30a and the second processed surface 30b in the thickness direction Z, that is, the thickness T1 of the processed portion 30, is, for example, approximately constant. The thickness T1 of the processed portion 30 is, for example, 50% or more and less than 100% of the thickness T0 of the rectangular conductor 10 before performing the thinning step S2.

Furthermore, in step S2 of thinning, the portion 20 defined based on the plurality of neutral lines L is thinned, and a plurality of processed portions 30 are formed as shown in FIG. 6D. The plurality of processed portions 30 are formed spaced apart from each other in a predetermined spacing pattern. The predetermined separation distance pattern is, for example, a pattern in which first separation distances d1 and second separation distances d2 different from the first separation distances d1 are arranged alternately. The first separation distance d1 is, for example, longer than the second separation distance d2. Further, the predetermined separation distance pattern may be a pattern in which the elements are spaced at equal intervals.

The processing conditions of the processing device 60 are determined based on data input to the control device 50. When the processing device 60 is a pressing device, the pressing speed is, for example, 100 mm/s. The pressing pressure is, for example, 5 tons.

In the embodiment, the processed portion 30 is formed by pressing the portion 20 defined based on the neutral line L. However, the portion 20 defined based on the neutral line L may be processed by cutting, etc. , the thickness may be reduced by other processing methods. In this case, step S2 of thinning is performed by a processing device that is a cutting device, for example. The portion 20 defined based on the neutral line L is cut by a cutting device.

(Step of bending)
Returning to FIG. 5, in step S3 of bending, the rectangular conductor 10 is bent with the thinned processed portion 30 facing the first connection surface 13 inside. That is, as shown in FIG. 6E, the rectangular conductor 10 is edgewise bent with the first connection surface 13 facing inside. As a result, the rectangular conductor 10 after being bent includes a bent portion 90, one straight portion 91, and the other straight portion 92. One straight portion 91 is continuous with one end 90a of the bent portion 90 and is a portion that cannot be bent in step S3 of bending. The other straight portion 92 is a portion that is continuous with the other end 90b of the bent portion 90 and is not bent in the bending step S3.

In step S3 of bending, each of the plurality of processed parts 30 of the rectangular conductor 10 shown in FIG. 6D is bent in order, and the rectangular conductor 10 is wound in a spiral shape. In other words, the rectangular conductors 10 are laminated in the thickness direction Z and wound. The first main surface 11 (or second main surface 12) of the rectangular conductor 10 forming one layer of two adjacent layers in the stack, and the second main surface 12 of the rectangular conductor 10 forming the other layer. (or the first main surface 11) and are wound in contact with each other.

Step S3 of bending is performed by the bending device 70. For example, the bending device 70 bends the first connecting surface 13 of the processed portion 30 by bringing it into contact with a columnar member. Alternatively, the first connection surface 13 of the processed portion 30 may be brought into contact with the teeth 3 of the stator core 2 shown in FIG. 1, and the rectangular conductor 10 may be directly wound around the teeth 3 of the stator core 2.

The bending conditions of the bending device 70 are determined based on data input to the control device 50. The bending speed is, for example, 50 mm/s. The bending radius R is, for example, R5 mm or less.

(effect)
In the coil manufacturing method as described above, before step S3 of bending, the portion 20 defined based on the neutral line L can be thinned to form the processed portion 30. Thereby, variations in the thickness of the rectangular conductor 10 due to bending step S3 can be suppressed. As a result, the space factor of the rectangular conductor 10 is improved, and a coil with an increased amount of current can be manufactured.

Furthermore, in the coil manufacturing method as described above, the width X2 of the processed portion 30 along the length direction X increases from the vicinity of the neutral line L to the first connection surface 13. Thereby, in step S3 of bending, the volume of the processed portion 30 can be reduced in accordance with the compressive stress that increases from the neutral line L toward the first connection surface 13. Therefore, with the coil manufacturing method as described above, variations in the thickness of the rectangular conductor 10 due to bending step S3 can be further suppressed.

In addition, in the above-described coil manufacturing method, in the thinning step S2, the rectangular conductor 10 is thinned from both the first main surface 11 and the second main surface 12. Thereby, the rectangular conductor 10 can be symmetrically thinned in the thickness direction Z, and variations in the thickness of the rectangular conductor 10 due to bending step S3 can be further suppressed.

Further, in the coil manufacturing method as described above, the shape of the processed portion 30 when viewed from the thickness direction Z is a shape having an apex located near the neutral line L. Thereby, the portion to which compressive stress is applied in step S3 of bending can be thinned before step S3 of bending. Thereby, variations in the thickness of the rectangular conductor 10 due to bending step S3 can be further suppressed.

Furthermore, in the coil manufacturing method as described above, the shape of the processed portion 30 when viewed from the thickness direction Z is triangular. This facilitates the formation of the processed portion 30.

Further, the coil manufacturing method as described above further includes step S1 of fixing the peripheral portion 24 of the portion 20 defined based on the neutral line L of the rectangular conductor 10. This makes it possible to suppress changes in the thickness of the peripheral portion 24 of the portion 20 defined based on the neutral line L in the thinning step S2, so that the thickness of the rectangular conductor 10 in the subsequent bending step S3 can be suppressed. Variations in height can be further suppressed.

The above-described coil manufacturing apparatus can also achieve the same effects as the coil manufacturing method.

<Modification 1>
The processed portions 30 according to the embodiment have substantially the same thickness T1, but are not limited to this. As shown in FIG. 11A, the thickness of the processed portion 130 according to Modification Example 1 is, for example, continuously thinner as it approaches the first connection surface 13 from the vicinity of the neutral line L. In other words, the first processed surface 130a and the second processed surface 130b are surfaces that are inclined with respect to the width direction Y from the second connection surface 14 toward the first connection surface 13.

Such a processed portion 130 is formed, for example, by pressing the portion 20 defined based on the neutral line L from a direction having an angle to the thickness direction Z.

(effect)
With such a configuration, in step S3 of bending, the volume of the processed portion 30 can be reduced in accordance with the compressive stress that increases from the neutral line L toward the first connection surface 13. Thereby, variations in the thickness of the rectangular conductor 10 due to bending step S3 can be further suppressed.

Furthermore, by pressing the portion 20 defined based on the neutral line L from a direction having an angle to the thickness direction Z, the processing load applied to the rectangular conductor 10 can be reduced.

<Modification 2>
Further, as shown in FIG. 11B, the thickness of the processed portion 230 according to Modification 2 becomes thinner toward the center of the processed portion 230 in the length direction X, for example. For example, the first processed surface 230a includes a first surface 230c that is inclined with respect to the length direction X from one end 15 to the other end 16, and a first surface 230c that is inclined with respect to the length direction 2 sides 230d. Similarly, the second processed surface 230b includes a first surface that is inclined with respect to the length direction X from one end 15 to the other end 16, and a second surface that is inclined with respect to the length direction Contains 2 sides.

Furthermore, the thickness of the processed portion 230 may become thinner as it approaches the first connection surface 13. For example, in addition to being inclined with respect to the length direction The surface may be inclined with respect to the width direction Y. Similarly, for example, the first surface of the second processed surface 230b and the second surface of the second processed surface 230b are inclined from the second connection surface 14 to the first connection surface 13 in addition to the inclination with respect to the length direction X. It may be a surface that is inclined with respect to the width direction Y.

(effect)
With this configuration, the volume of the processed portion 30 is increased in accordance with the compressive stress that increases from one end 90a and the other end 90b of the bent portion 90 toward the center of the bent portion 90 in the length direction Xa. can be reduced. Thereby, variations in the thickness of the rectangular conductor 10 due to bending step S3 can be further suppressed.

<Modification 3>
Further, as shown in FIG. 11C, the shape of the processed portion 330 according to Modification Example 3 when viewed from the thickness direction Z is, for example, a semicircular shape. At least a portion of the processed portion 330 is located near the neutral line L when viewed from the thickness direction Z. At least a portion of the processed portion 330 may be one point on the semicircular outer contour of the processed portion 330 when viewed from the thickness direction Z.

(effect)
With such a configuration, the volume of the processed portion 30 can be reduced in accordance with the compressive stress that increases from the neutral line L toward the first connection surface 13 in the bending step S3. can. Thereby, variations in the thickness of the rectangular conductor 10 due to bending step S3 can be further suppressed.

<Modification 4>
Furthermore, although the shape of the processed portion 30 according to the embodiment when viewed from the thickness direction Z is triangular, the shape is not limited to this. As shown in FIG. 11D, the shape of the processed portion 430 according to Modification 4 when viewed from the thickness direction Z is, for example, a trapezoid. The shape of the processed portion 430 viewed from the thickness direction Z is, for example, a trapezoid shape in which two vertices and a side connecting the two vertices are located near the neutral line L. In the shape of the processed portion 430 viewed from the thickness direction Z, the width in the length direction X becomes longer as it approaches the first connection surface 13.

(effect)
With such a configuration, even if an error occurs in the position of the neutral line L or the range of compressive stress depending on the bending conditions, the material condition of the rectangular conductor 10, etc., the thickness of the rectangular conductor 10 in step S3 of bending can be adjusted. Variations in height can be further suppressed.

Coils obtained by the coil manufacturing method and coil manufacturing apparatus according to the present disclosure can be applied as parts for electrical appliances, automobile parts, daily necessities, and the like.

1 Coil 2 Stator core 3 Teeth 10 Rectangular conductor 11 First principal surface 12 Second principal surface 13 First connection surface 14 Second connection surface 15 One end 16 Other end 20 Portion defined based on the bending neutral line of the rectangular conductor (The part defined based on the neutral line)
21 First vertex 22 Second vertex 23 Third vertex 24 Surrounding

portion

30, 130, 230, 330, 430

Processing portion

30a, 130a, 230a

First processing surface

30b, 130b, 230b Second processing surface 31, 31a, 31b 1 vertex 32, 32a, 32b 2nd vertex 33, 33a, 33b 3rd vertex 40 Coil manufacturing device 50 Control device 60 Processing device 61 1st tool 62 2nd tool 63 Fixing device 70 Bending device 90 Bending portion 90a One end Part 90b Other end 91 One straight part 92 Other straight part 230c First surface 230d Second surface d1 First separation distance d2 Second separation distance L Neutral line of bending of rectangular conductor (neutral line)
T0, T1 Thickness X1, X2, X3 Width W Width

Claims

a first main surface, a second main surface located opposite to the first main surface, a first connection surface connecting the first main surface and the second main surface; A coil manufacturing method for manufacturing a coil by processing a rectangular conductor having two main surfaces connected to each other and a second connection surface located opposite to the first connection surface, the method comprising:
processing the processed portion so that the processed portion defined based on the neutral line of bending of the rectangular conductor is thinner than other portions other than the processed portion;
bending the rectangular conductor so that the first connection surface is inside the rectangular conductor;
Coil manufacturing method, including:
The coil manufacturing method according to claim 1, wherein the width of the processed portion along the length direction of the rectangular conductor becomes wider as it approaches the first connection surface from near the neutral line.
The coil manufacturing method according to claim 1 or 2, wherein the thickness of the processed portion becomes thinner as it approaches the first connection surface from the neutral line.
The coil manufacturing method according to any one of claims 1 to 3, wherein in the processing step, the processing portion is processed from both the first main surface and the second main surface.
The coil manufacturing method according to any one of claims 1 to 4, wherein the thickness of the processed portion becomes thinner toward the center of the processed portion in the length direction of the rectangular conductor.
The coil manufacturing method according to any one of claims 1 to 5, wherein the shape of the processed portion when viewed from the thickness direction of the rectangular conductor is a shape having an apex located near the neutral line.
The coil manufacturing method according to claim 6, wherein the processed portion has a triangular shape when viewed from the thickness direction of the rectangular conductor.
The coil manufacturing method according to any one of claims 1 to 7, further comprising the step of fixing the other portion from the thickness direction of the rectangular conductor.
The coil manufacturing method according to any one of claims 1 to 8, wherein in the processing step, the processing portion is press-processed.
a first main surface, a second main surface located opposite to the first main surface, a first connection surface connecting the first main surface and the second main surface; A coil manufacturing device for manufacturing a coil by processing a rectangular conductor having two main surfaces connected to each other and a second connection surface located opposite to the first connection surface,
a processing device that processes the processed portion such that the processed portion defined based on the neutral line of bending of the rectangular conductor is thinner than other portions other than the processed portion;
a bending device that bends the rectangular conductor so that the first connection surface is on the inside of the rectangular conductor;
Coil manufacturing equipment, including:
11. The coil manufacturing apparatus according to claim 10, wherein the width of the processed portion along the length direction of the rectangular conductor increases as it approaches the first connection surface from near the neutral line.
The coil manufacturing apparatus according to claim 10 or 11, wherein the thickness of the processed portion becomes thinner as it approaches the first connection surface from the vicinity of the neutral line.
The coil manufacturing device according to any one of claims 10 to 12, wherein the processing device processes the processed portion from both the first main surface and the second main surface.
The coil manufacturing device according to any one of claims 10 to 13, wherein the thickness of the processed portion becomes thinner toward the center of the processed portion in the length direction of the rectangular conductor.
The coil manufacturing apparatus according to any one of claims 10 to 14, wherein the shape of the processed portion when viewed from the thickness direction of the rectangular conductor is a shape having an apex located near the neutral line.
The coil manufacturing apparatus according to claim 15, wherein the processed portion has a triangular shape when viewed from the thickness direction of the rectangular conductor.
The coil manufacturing apparatus according to any one of claims 10 to 16, further comprising a fixing device that fixes the other portion from the thickness direction of the rectangular conductor.
The coil manufacturing device according to any one of claims 10 to 17, wherein the processing device press-processes the processed portion.