JP2008228434A - Coil manufacturing method - Google Patents

Abstract

A coil manufacturing method capable of increasing the winding speed of a coil.
In a method of manufacturing a coil formed by edgewise bending a flat member 15, the flat member 15 is temporarily wound around a cylindrical winding shaft 62 using a winding device 60, and the flat member 15 is substantially circular. The temporary winding step of forming the temporary winding coil 11 and the temporary winding coil 11 are temporarily attached to the coil forming jig 20 using a coil forming jig 20 whose outer peripheral shape gradually changes from a circular shape to a polygonal shape. A coil forming step of inserting a wound coil 11 and forming a rectangular coil of a rectangular material 15 formed into a rectangular shape.
[Selection] Figure 2

Description

  The present invention relates to a technique for forming a coil used in a motor by edgewise bending a rectangular material.

The coil used for a motor is generally formed by winding an enamel-coated conductive wire. However, because of the demand for higher output and smaller size of the motor, the current density can be increased and heat dissipation is good. A method of manufacturing a coil using a flat rectangular material has been proposed.
A coil using a rectangular material may be formed by a method of cutting a straight rectangular material into a predetermined length and joining at a coil end, or by performing edgewise bending.
The coil formed by edgewise bending can reduce the electrical resistance in terms of reducing the number of joints, and a reduction in the defect rate can be expected.
Patent Document 1 discloses a technique related to a winding device and a winding method. A specific machine configuration for edgewise bending using a flat bar is shown. By winding by this method, it becomes possible to stably wind the flat material.

However, there is a problem that when the flat material is edgewise bent, the inner peripheral side of the coil swells. This is because the edge-wise bending causes the thickness of the flat rectangular material to rise in the thickness direction due to the difference in length between the inner periphery and the outer periphery.
Thus, when the inner peripheral side of the coil swells, the space factor of the rectangular material in the slot provided in the coil decreases.
In order to solve such a problem, techniques as disclosed in Patent Document 2 and Patent Document 3 are disclosed.

  Patent Document 2 discloses a technique relating to a stator for an electric motor and a winding device for a winding material. When edge-wise bending a rectangular material, it is possible to eliminate the difference between the length of the outer periphery and the inner periphery by providing a notch inside the bent part and winding it, thereby preventing the expansion of the rectangular material Is possible.

  In patent document 3, the technique regarding the coil of a rotary electric machine, the rotary electric machine, and the manufacturing method of a coil is disclosed. In Patent Document 2, instead of eliminating the bulge that occurs during edgewise bending, in order to prevent the width of the coil from expanding due to interference between the bulges, the coil end is unwound and the width is reduced. It is suppressed.

Japanese Patent No. 3585438 (paragraph 28-, FIG. 1) Japanese Patent Laying-Open No. 2005-354804 (paragraphs 22 to 52, FIGS. 3 and 8) Japanese Patent Laying-Open No. 2005-304244 (paragraph 42 to FIG. 6)

However, the conventional techniques disclosed in Patent Documents 1 to 3 are considered to have a problem that it is difficult to increase the winding speed.
The stator used for the motor has a larger number of poles, and it is easier to suppress the torque unevenness of the motor. Therefore, the coil used for the stator tends to be thin. In order to form such a coil, in Patent Documents 1 to 3, a rectangular material is wound in a substantially rectangular shape.
FIG. 9 shows a state in which the rectangular coil 100 of the prior art is wound.
FIG. 9 shows a state in which the rectangular member 115 starts to be wound from the winding start end 100 a of the rectangular coil 100 and is wound several turns, the supply end 100 b is fixed, and the rotating shaft 120 is the same rectangle as the inner periphery of the rectangular coil 100. It has a shape.

Due to the configuration of the winding devices described in Patent Document 1 and Patent Document 2, it is considered that when the substantially rectangular rectangular coil 100 is wound, the winding speed can be uneven.
That is, as shown in FIG. 9, when the supply end 100b of the rectangular coil 100 is wound on the short side, assuming that the rotary shaft 120 rotates at a constant speed, the distance from the axis C of the rotary shaft 120 Becomes the long axis A, so that the winding speed is fast, and when the supply end 100b winds the long side, the distance from the axis C becomes the short axis B, so the winding speed becomes slow. The rectangular coil 100 is formed by winding the rectangular material 115 while repeating this alternately.
That is, the speed at which the flat material 115 is supplied to the supply end 100b changes and appears as speed unevenness.
In addition, although patent document 3 does not have an explicit description in the winding method, it is thought that there exists the same problem as long as a coil is a rectangle.

The speed unevenness that occurs when the flat rectangular material 115 is wound becomes a factor that causes winding disturbance when the rectangular coil 100 is wound. For this reason, it is necessary to adjust the acceleration / deceleration of rotation in order to make the supply speed of the flat material 115 to the supply end 100b constant, and to make the winding speed constant.
At this time, since it is difficult to adjust the winding speed to the faster one, the winding speed is adjusted to the slower one. However, when excessive acceleration is applied, the winding speed is about several tens of rpm due to the possibility that the flat material 115 may be unnecessarily stretched.
Under such circumstances, when winding a substantially rectangular coil, it is difficult to achieve a certain speed or higher. Accordingly, there is a problem that it takes time to form the coil, making it difficult to reduce the cost.

  Therefore, an object of the present invention is to provide a method for manufacturing a coil that can increase the winding speed of the coil in order to solve such a problem.

In order to achieve the above object, a method of manufacturing a coil according to the present invention has the following characteristics.
(1) In a coil manufacturing method in which a flat material is formed by edgewise bending,
A temporary winding step of temporarily winding the flat material on a cylindrical temporary winding jig, and forming the temporary winding coil by performing edgewise bending processing of the flat rectangular material into a substantially circular shape, Using a coil forming jig whose shape gradually changes from a circle to a polygon, the temporary winding coil is inserted into the coil forming jig, and a coil for forming a square wound coil in which the rectangular material is formed into a polygon. And a molding step.

(2) In the coil manufacturing method according to (1),
A polygonal portion of the coil forming jig is provided with first coil pressing means for applying a compressive force in the winding direction of the coil during forming from the temporary coil to the square coil. In addition, the square coil is formed by applying a compressive force in the winding direction by the first coil pressing means with the temporary coil mounted.

(3) In the coil manufacturing method according to (2),
A second coil pressing means that press-molds from the circumferential direction of the coil toward the concave portion of the coil-forming jig during molding, and is formed into a concave shape in which each side of the polygon of the coil-forming jig is recessed inward; Before the forming coil attached to the polygonal portion by the first coil pressing means is compressed in the winding direction, the forming coil is press-formed by the second coil pressing means. Features.

(4) In the method for manufacturing a coil according to any one of (1) to (3),
The shape of the temporary winding coil is such that the peripheral length of one turn of the temporary winding coil is substantially equal to the peripheral length of one turn of the square winding coil wound around the outer periphery of the coil forming jig. The shape of the temporary winding jig is set.

(5) In the coil manufacturing method according to (4),
The square wound coil formed using the coil forming jig is annealed.

With the coil manufacturing method according to the present invention having such characteristics, the following operations and effects can be obtained.
First, the invention described in (1) is a coil manufacturing method in which a rectangular material is formed by edgewise bending, and the rectangular material is temporarily wound around a cylindrical temporary winding jig so that the rectangular material is substantially circular. A coil-forming jig using a temporary-winding process for forming a temporary-winding coil that has been edgewise bent into a temporary winding coil and a coil-forming jig whose outer peripheral shape gradually changes from a circular shape to a polygonal shape. And a coil forming step of forming a square wound coil in which a flat rectangular material is formed into a polygon, and when the flat rectangular material is wound, it may be wound in a substantially circular shape.

When forming a coil by edgewise bending a rectangular material, if it is wound in a substantially circular shape, it is not necessary to wind it into a rectangle as shown in FIG. It is possible to wind at high speed without causing unevenness. In the conventional method, it was necessary to suppress the winding speed to several tens to several tens of rpm, but with the method (1), it is possible to wind at a speed of several hundred rpm or more, and several tens of times The coil can be wound at the speed of
Moreover, after temporary winding, it can shape | mold into a coil of a required shape at the coil shaping | molding process shape | molded into a rectangle using a coil shaping jig. In the coil forming step, a simple method of inserting and forming a temporary winding coil in a coil forming jig is employed, so that it can be formed in a short time to form a square winding coil.
Therefore, as compared with the case of forming the square winding coil by the conventional winding method as shown in FIG. 9, a method of forming a substantially circular temporary winding coil and forming it into the square winding coil in the coil forming process is adopted. Thus, the time required for coil forming can be shortened.

The invention described in (2) is the coil manufacturing method described in (1), in which a compressive force is applied to the winding direction of the coil being formed during the formation from the temporary winding coil to the square winding coil. 1 coil pressing means, and in the coil forming process, with the temporarily wound coil mounted on the polygonal portion of the coil forming jig, the first coil pressing means applies a compressive force in the winding direction, Since the shape coil is formed, the width of the flat material forming the coil can be formed to a predetermined thickness.
It has been confirmed that when a flat rectangular material is edgewise bent, the thickness of the inner peripheral side of the coil expands at the edgewise bent portion. This is because when the straight rectangular material is edgewise bent, the inner peripheral side of the bent portion is compressed, and the excess meat on the inner peripheral side moves in the thickness direction of the rectangular material.
A similar phenomenon occurs even when a temporarily wound coil wound in a substantially circular shape is formed into a square winding shape. Therefore, by applying a compression force in the coil winding direction by the coil compression means, the bulge on the inner peripheral side of the coil can be reduced. It can be corrected. As a result, when the coils are arranged in the slots provided in the stator, the space factor of the coils in the slots can be increased.

Further, the invention described in (3) is the coil manufacturing method described in (2), wherein the second coil pressing means that press-molds from the circumferential direction of the coil being molded toward the concave portion of the coil-forming jig. Before forming the coil during molding formed into a concave shape in which each side of the polygon of the coil forming jig is recessed inward, and being attached to the polygonal portion by the first coil pressing means, in the winding direction, Since the coil is being pressed by the second coil pressing means, the minimum bend R of the corner of the coil can be reduced.
When used in a situation where demands for miniaturization and high output are severe, such as when used for motors mounted on vehicles, we want to make the physique of the coil as small as possible.

Therefore, when the temporary coil wound in a substantially circular shape is inserted into the coil forming jig and inserted into the polygonal portion, the concave shape of the coil forming jig is formed from the circumferential direction of the coil being formed by the second coil pressing means. By pressing toward the portion, the minimum bending radius of the edgewise bending portion of the coil can be reduced to be equal to or smaller than the flat plate width.
As a result, the size of the square coil can be reduced, and when mounted on a motor, the coil end portion of the motor can be shortened.

Moreover, the invention described in (4) is the coil manufacturing method according to any one of (1) to (3), in which the peripheral length of one turn of the temporary winding coil and the outer periphery of the coil forming jig are Since the shape of the temporary winding coil and the shape of the temporary winding jig are set so that the peripheral length of one turn of the wound rectangular winding coil is substantially equal, the temporary winding coil is formed by the coil forming jig. When forming, the coil can be formed into a square winding shape with a minimum force.
When the circumference of one turn wound around the outer periphery of the coil forming jig is not equal to the circumference of one turn of the temporary winding coil, when the temporary winding coil is formed with the coil forming jig, A force acts in the direction of moving in the winding direction or extending the flat bar. For this reason, a large force is required at the time of coil forming, and it takes time to form, and it is difficult to ensure the dimensional accuracy of the coil.
However, by making the circumference of one turn wound around the outer periphery of the coil forming jig equal to the circumference of one turn of the temporary coil, the force acting in the coil winding direction is minimized. Therefore, it is possible to shorten the coil forming time, and there is no dimensional change due to the extension of the rectangular material, so that it is possible to provide a coil with high dimensional accuracy.

In addition, the invention described in (5) is the method for manufacturing a coil described in (4), in which the square wound coil formed by using the coil forming jig is annealed, so that the work hardening is performed at the edgewise bending portion. Even when this occurs, it becomes possible to remove the influence of work hardening.
If work hardening occurs when a flat material is edgewise bent, the resistance value of the coil increases. This is because the movement of electrons is hindered because many dislocation lines are entangled in the material of the edgewise bent portion.
Therefore, it is possible to prevent an increase in the resistance value of the edgewise bent portion of the coil by removing the influence of work hardening from the material by annealing the coil in an annealing furnace or the like.

Next, embodiments of the present invention will be described with reference to the drawings.
First, the outline of the structure of the coil manufacturing method of the present embodiment will be briefly described.
FIG. 1 is a perspective view of the coil 10.
The coil 10 is wound in a rectangular shape using a flat bar 15. The rectangular material 15 is a strip-shaped conductor whose cross section is rolled into a rectangle using a metal having high conductivity such as copper. The flat material 15 of this embodiment has a thickness of about 1 mm and a width of about 5 mm.
An insulating coating is applied around the flat rectangular member 15. The insulating coating is made of a highly insulating material such as enamel, polyimide, or amideimide, and is formed around the flat material 15 by about several tens of μm.
The coil 10 in such a state is mounted on a stator (not shown) to form a motor. Motors are used as driving power for automobiles. Of course, it does not prevent use for other purposes.

The process of forming the coil 10 is as follows.
FIG. 2 shows a state where the temporary winding coil 11 is inserted into the coil forming jig 20. FIG. 3 shows a step of winding the temporary winding coil 11.
FIG. 4 shows an AA cross section of the coil forming jig 20. FIG. 5 shows a BB cross section of the coil forming jig 20. FIG. 6 shows a CC cross section of the coil forming jig 20.
As shown in FIG. 2, the temporary winding coil 11 is a coil in which a flat wire 14, which is a flat material 15 that is not insulated and coated in a substantially conical shape, is wound. This temporary coil 11 is wound by a winding device 60 as shown in FIG.
The winding device 60 includes a base 61, a winding shaft 62, and the like, and winds the flat wire 14 fixed to a fixing portion (not shown) provided on the winding shaft 62. The winding shaft 62 has a substantially conical shape. By winding the flat wire 14, the flat wire 14 is wound in a substantially circular shape, and a substantially conical temporary coil is formed along the shape of the winding shaft 62. 11 is formed. Although not shown, it is preferable to provide a guide for holding the flat wire 14 as necessary.

The temporary winding coil 11 formed in this way is inserted into the coil forming jig 20.
The coil forming jig 20 is a jig formed in a shape in which a circular portion 20a, an elliptical portion 20b, and a polygonal portion 20c are continuously changed as shown in FIG. The circular portion 20a is shown in FIG. 4, the oval portion 20b is shown in FIG. 5, and the polygonal portion 20c is shown in FIG.
In FIG. 2, the shape of the coil forming jig 20 is expressed as a low height due to a problem in creating a drawing. It is preferable that an excessive force is not applied when the temporary winding coil 11 is deformed by gradual change of the shape 20.
The outer peripheral length of each of the circular portion 20 a, the elliptical portion 20 b, and the polygonal portion 20 c of the coil forming jig 20 is substantially equal to the inner peripheral length of the temporary winding coil 11. In addition, the outer periphery of the front-end | tip part of the circular part 20a is made smaller than the inner periphery of the temporary winding coil 11 so that the temporary winding coil 11 can be inserted easily. The tip of the coil forming jig 20 may be spherical so that the temporary winding coil 11 can be easily inserted.

The coil forming jig 20 is made of a material having high hardness such as tool steel, and the surface thereof is subjected to buffing or the like so as to reduce the frictional resistance.
The temporary winding coil 11 is inserted into the coil forming jig 20 from the circular portion 20a side as shown in FIG.
Then, pressure is applied from the upper surface of the temporary winding coil 11 to push the temporary winding coil 11 downward, and the temporary winding coil 11 is gradually deformed. For convenience of explanation, the temporary winding coil 11 being formed will be referred to as a forming coil 12.
As the forming coil 12 approaches the elliptical portion 20b, it is gradually formed into an elliptical shape in accordance with the cross-sectional shape of the elliptical portion 20b of the coil forming jig 20. This is shown in FIG.

Then, as shown in FIG. 6, when reaching the polygonal portion 20c, the coil 12 during molding is formed into a rectangle by the corner portion 20c3. The cross section of the polygonal portion 20c has a shape in which each side of the rectangle is recessed. The concave long side concave portion 20c1 and the concave long side concave portion 20c2 are gently formed in an arc shape, and are gradually formed deeper as the distance from the temporary winding coil 11 insertion side of the coil forming jig 20 increases. Yes.
And R is formed in the corner | angular part 20c3 with the radius shorter than the width | variety of the long side of the flat rectangular material 15. FIG. The corner 20c3 forms an edgewise bent portion of the coil 12 during molding.
In this way, after the forming coil 12 is inserted to the polygonal portion 20c and continuously deformed, the outer diameter of the forming coil 12 is formed by the first coil pressing means and the second coil pressing means. .

FIG. 7 is a sectional view showing a state in which the forming coil 12 is being compressed and deformed by the circumferential coil compression means 30.
With the coil 12 being formed reaching the polygonal portion 20c, the circumferential coil compression means 30 corresponding to the second coil pressing means is pressed so as to be compressed and deformed toward the center from the circumferential direction of the coil 12 being formed.
The circumferential coil compression means 30 includes a long side pressing mechanism 31 corresponding to the long side concave shape portion 20c1 and a short side pressing mechanism 32 corresponding to the short side concave shape portion 20c2.
As shown in FIG. 7, the long side pressing mechanism 31 and the short side pressing mechanism 32 are formed in an arc cross section as shown in FIG. 7, and have substantially the same shape as the arcs of the long side concave shape portion 20c1 and the short side concave shape portion 20c2. I am doing.
In a state where the coil 12 being formed is simply passed through the coil forming jig 20, it is difficult for the edgewise bending portion 12a of the coil 12 being formed to have a bending radius smaller than the plate width. Since it has a swelled shape, the bending radius of the edgewise bending portion 12a is reduced by pressing the coil 12 during molding toward the center from the circumferential direction of the coil 12 during molding by the circumferential coil compression means 30. It becomes possible to make it smaller than the width.

In FIG. 8, the side view showing a mode that the coil 12 during shaping | molding is compressively deformed by the winding direction coil compression means 40 is shown.
After the coil forming jig 20 is pressed by the circumferential coil compression means 30 from the circumferential direction toward the center, the coil 12 being formed is crushed by using the winding direction coil compression means 40 corresponding to the first coil pressing means.
The winding direction coil compression means 40 is shown in FIG. 8 in a state of pressing the entire coil 12 during molding, but the portion that is most pressed to correct the plate thickness is the edgewise bending portion of the coil 12 during molding. Since it is 12a, the shape which presses down the four corners of the coil 12 during shaping | molding may be sufficient.

Thus, the coil 10 is formed in the shape of the coil 10 by pressing the coil 12 during molding by the winding direction coil compression means 40 and molding it. However, in this state, since the insulation coating is not applied around the rectangular wire 14 constituting the coil 10, it is necessary to perform an annealing process and an insulation coating process thereafter.
The annealing treatment is performed by heating to a certain temperature or higher in a furnace (not shown) and gradually cooling in order to remove processing distortion accumulated in the edgewise bent portion 10a of the coil 10. By performing such an annealing process, the influence of work hardening generated in the edgewise bent portion 10a of the coil 10 is removed or alleviated.
Thereafter, the coil 10 is subjected to an insulation coating process by electrodeposition coating or the like to form the coil 10 with an insulation coating.

Since the manufacturing method of the coil of a present Example becomes the above structures, there exists an effect | action and effect as shown below.
First, the coil 10 is wound as the temporary coil 11, and then formed into a square-wound coil 10 using the coil forming jig 20, the circumferential coil compression means 30, and the winding direction coil compression means 40. Therefore, processing time can be shortened.
As described above, when the coil 10 is edgewise bent into a square winding shape, there is a problem that the winding speed cannot be increased because a speed difference occurs between the short side and the long side.
In the case of forming the coil 10 by performing edgewise bending into a square winding shape, a speed of about a dozen rpm is the limit. On the other hand, when the coil is wound in a cylindrical shape like the temporary winding coil 11, it can be wound at a speed of about several hundreds of rpm, so that it can be wound several tens of times faster. it can.

  The temporary winding coil 11 can be formed into a square coil 12 having a square winding shape through a step of forming by the coil forming jig 20, the circumferential direction coil compressing means 30, and the winding direction coil compressing means 40. In this process, since the flat material 15 is a copper material, the deformation is easy, and the processing is completed without much time. Therefore, although the number of processes is increased as compared with the case where the rectangular coil 100 is wound using the rotating shaft 120 as shown in FIG. 9, the total processing time can be shortened.

Secondly, the body 10 of the coil 10 can be made smaller by pressing the coil 12 during molding from the circumferential direction toward the center using the circumferential coil compression means 30.
It is difficult to make the bending radius of the edgewise bending portion 12a of the coil 12 being formed smaller than the plate width of the flat wire 14 simply by passing the temporary winding coil 11 through the polygonal portion 20c of the coil forming jig 20. . This is because the substantially conical temporary winding coil 11 is gradually deformed through the coil forming jig 20, and when the forming coil 12 reaches the polygonal portion 20c, the rectangular wire 14 of the forming coil 12 is It tends to be a shape that bulges outward.
In order to deform from the substantially conical temporary winding coil 11, the straight portion has an arc shape, and is corrected by pressing this with the long side pressing mechanism 31 and the short side pressing mechanism 32 of the circumferential coil compression means 30. Thus, the coil 12 is formed into a square winding shape during molding.

Moreover, the edgewise bending process part 12a of the coil 12 during shaping | molding can make the bending radius shorter than the plate width of the flat wire 14 by doing in this way. Therefore, when assembled to the stator in a state of being processed into the coil 10, it can contribute to shortening of the coil end of the stator.
By the way, by making the bending radius of the edgewise bending portion 12a of the coil 12 during forming shorter than the plate width of the flat wire 14, work hardening occurring in the edgewise bending portion 12a is increased, but coil forming is performed. It can be solved by annealing after molding with the jig 20.
When the edgewise bending portion 12a of the coil 12 during molding, that is, the edgewise bending portion 10a of the coil 10 is work-hardened, the biggest problem is that the resistance value of the coil 10 increases.
As long as the applicant confirms, when work hardening occurs in the edgewise bending portion 12a, the resistance value increases by several percent. Such an increase in resistance value is not preferable because it leads to heat generation of the motor and causes a reduction in life. However, it is possible to remove and mitigate work hardening by annealing the coil 12 during molding after molding, which leads to suppressing such an increase in resistance of the coil 10.

Third, the coil 12 being formed is compressed by the winding direction coil compression means 40, and the coil 12 being formed is edgewise bent, so that the increased plate thickness of the rectangular wire 14 is reduced to a predetermined thickness. Can be press-molded.
After passing the temporary winding coil 11 through the coil forming jig 20, it is pressed from the circumferential direction of the coil 12 being formed by the circumferential coil compression means 30 at the position of the polygonal portion 20 c, and then the winding direction coil compression means. 40 is used for press molding.
When the flat wire 14 or the flat material 15 is edgewise bent, there is a phenomenon that the dimension increases in the thickness direction of the flat wire 14 or the flat material 15. This is because the difference between the length of the outer periphery and the length of the inner periphery of the bent portion of the flat wire 14 or the rectangular material 15 is generated, the outer peripheral portion is stretched, the inner peripheral portion is compressed, and the meat of the material Is moved to escape in the plate thickness direction of the rectangular wire 14 or the rectangular material 15 and the thickness is increased.

Accordingly, even when the coil 12 being formed is pressed by the circumferential coil compression means 30, the plate thickness of the flat wire 14 is increased, and the coil 12 is wound so as to be corrected to a predetermined thickness. A compression force is applied by the winding direction coil compression means 40 in the overlapping direction, and press molding is performed.
When the thus formed coil 10 is disposed in the slot of the stator, it contributes to increasing the space factor of the coil 10 with respect to the slot.
The improvement of the space factor responds to the demand for miniaturization and higher output of the vehicle-mounted motor.

In addition, by performing an insulating coating process after forming the coil 12 during forming, the insulating film may be damaged during the press forming of the coil 12 being formed by the circumferential coil compression means 30 or the winding direction coil compression means 40. There is no.
Since the insulating film provided on the coil 10 affects the space factor when disposed on the stator, it is desirable that the insulating film be formed as thin as possible and obtain necessary insulation.
For this reason, there are many cases in which an insulation coating of about several tens of μm is provided, but there is a risk of damaging such an insulation coating during external pressurization such as the circumferential coil compression means 30 and the winding direction coil compression means 40. is there. In addition, the insulating film may be peeled off due to friction with the outer peripheral surface with which the coil 12 is in contact with the coil forming jig 20 during forming.
Therefore, it is possible to reduce the possibility of damaging the insulating film of the coil 10 as much as possible by forming the coil 10 in the procedure of performing the annealing process after the coil 12 is being pressed and then performing the insulating film process. .

As described above, the coil manufacturing method shown in the present embodiment can provide the following configuration, operation, and effects.
(1) In the manufacturing method of the coil formed by bending the flat material 15 edgewise, the flat wire 14 is temporarily wound around the cylindrical winding shaft 62 by using the winding device 60, and the flat wire 14 is substantially The temporary winding step of forming the temporary winding coil 11 temporarily wound in a circular shape and the coil forming jig 20 using the coil forming jig 20 whose outer peripheral shape gradually changes from a circular shape to a polygonal shape. A coil forming step of inserting a temporary winding coil 11 and forming a square wound coil in which the flat rectangular wire 14 is formed into a polygon, and when winding the flat rectangular wire 14, it is wound in a cylindrical shape. do it.

If the flat wire 14 is wound in an approximately circular shape when edgewise bending is performed, it is not necessary to change the winding speed, so that the winding speed can be wound at high speed without causing unevenness. In the conventional method, it was necessary to suppress the winding speed to several tens to several tens of rpm, but with the method (1), it is possible to wind at a speed of several hundred rpm or more, and several tens of times It is possible to wind the temporary winding coil 11 at a speed of 5 mm.
Moreover, after temporary winding, it can shape | mold into the coil 10 of a required shape at the coil shaping | molding process shape | molded into a rectangle using the coil shaping jig | tool 20. FIG.

(2) In the coil manufacturing method according to (1), the winding direction coil compression means 40 for applying a compressive force in the winding direction of the coil 12 being formed during the formation from the temporary winding coil 11 to the square winding coil. In the coil forming step, with the provisional winding coil 11 mounted on the polygonal portion 20c of the coil forming jig 20, the winding direction coil compression means 40 applies a compressive force in the winding direction to square winding. Since the shape coil is molded, the width of the flat member 15 forming the coil 10 can be formed to a predetermined thickness.
When the flat wire 14 or the flat material 15 is edgewise bent, it has been confirmed that the inner peripheral side of the coil 10 swells at the edgewise bent portion. This is because when the straight rectangular wire 14 or the rectangular material 15 is edgewise bent, the inner peripheral side of the edgewise bent portion 10a is compressed, and the remaining meat on the inner peripheral side moves in the thickness direction.
Even if the temporary winding coil 11 wound in a substantially conical shape is formed into a square winding shape, the same phenomenon occurs. Therefore, by applying a compressive force in the winding direction of the coil 10 by the winding direction coil compression means 40, the coil It is possible to correct the bulge on the inner peripheral side. As a result, when the coil 10 is disposed in the slot provided in the stator, the space factor of the coil 10 in the slot can be increased.

(3) In the coil manufacturing method according to (2), the circumferential direction in which press molding is performed from the circumferential direction of the coil 12 during molding toward the long-side concave shape portion 20c1 and the short-side concave shape portion 20c2 of the coil-forming jig 20. A coil compression means 30 is provided, and each side of the polygon of the coil forming jig 20 is formed in a concave shape, and the coil 12 being formed attached to the polygonal portion 20c by the winding direction coil compression means 40 is rolled up. Before the compressive force is applied in the direction, the coil 12 during molding is press-molded by the circumferential coil compression means 30, so that the minimum bend R of the edgewise bent portion 10a of the coil 10 can be reduced.
When it is used in a situation where a demand for miniaturization and high output is severe, such as when used for a motor mounted on a vehicle, it is desirable to make the physique of the coil 10 as small as possible.

Therefore, the temporary winding coil 11 wound in a conical shape is inserted into the coil forming jig 20 and inserted into the polygonal portion 20c, and then coiled from the circumferential direction of the coil 12 being formed by the circumferential coil compression means 30. The minimum bending radius of the edgewise bent portion 10a of the coil 10 can be reduced by press molding toward the long-side concave shape portion 20c1 and the short-side concave shape portion 20c2 of the jig 20.
As a result, the size of the square coil can be reduced, and when mounted on a motor, the coil end portion of the motor can be shortened.

(4) In the method for manufacturing a coil according to any one of (1) to (3), a circumferential length of one turn of the temporary winding coil 11 and a rectangular winding coil wound around the outer periphery of the coil forming jig 20 Since the shape of the temporary winding coil 11 and the shape of the winding shaft 62 are set so that the circumferential length of one turn of the winding coil 11 is substantially equal, when the temporary winding coil 11 is formed by the coil forming jig 20, The coil can be formed into a square winding shape with a minimum force.
When the circumference of one turn wound around the outer periphery of the coil forming jig 20 and the circumference of one turn of the temporary winding coil 11 are not equal, when the temporary winding coil 11 is formed with the coil forming jig 20 A force acts in the direction in which the flat wire 14 moves in the winding direction or the flat wire 14 extends. For this reason, a large force is required at the time of coil forming, and it takes time to form, and it becomes difficult to ensure the dimensional accuracy of the coil 10.
However, by making the circumference of one turn wound around the outer periphery of the coil forming jig 20 equal to the circumference of one turn of the temporary winding coil 11, the force acting in the coil winding direction is minimized. Since the coil forming time can be shortened and there is no dimensional change due to the extension of the flat wire 14, the coil 10 with high dimensional accuracy can be provided.

(5) In the method for manufacturing a coil according to (4), since the square wound coil formed by using the coil forming jig 20 is annealed, even when work hardening occurs in the edgewise bending portion 12a, It becomes possible to remove the influence of curing.
When work hardening occurs when the flat wire 14 is edgewise bent, the resistance value of the coil 10 increases. This is because there are many dislocation lines entangled in the raw material of the edgewise bent portion 10a, which hinders the movement of electrons.
Therefore, it is possible to prevent an increase in the resistance value of the edgewise bent portion 10a of the coil 10 by removing the influence of work hardening from the material by annealing the coil 10 in an annealing furnace or the like.

While the present invention has been described with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and can be appropriately modified and applied without departing from the scope of the invention.
For example, it does not prevent changing the shape of the circumferential coil compression means 30 and the winding direction coil compression means 40. Moreover, since it is sufficient that the temporary winding coil 11 can be wound with respect to the configuration of the winding device 60, the configuration other than the winding device 60 shown in FIG.

The perspective view of the coil 10 of a present Example is shown. The perspective view showing a mode that the temporary winding coil 11 of a present Example is inserted in the coil shaping jig | tool 20 is shown. The process of winding the temporary winding coil 11 of a present Example is shown. The AA cross section of the coil formation jig | tool 20 shown in FIG. 2 of a present Example is shown. The BB cross section of the coil shaping jig | tool 20 shown in FIG. 2 of a present Example is shown. The CC cross section of the coil shaping jig | tool 20 shown in FIG. 2 of a present Example is shown. Sectional drawing showing a mode that the coil 12 during shaping | molding is compressively deformed by the circumferential direction coil compression means 30 of a present Example is shown. The side view showing a mode that the coil 12 during shaping | molding is compressively deformed by the winding direction coil compression means 40 of a present Example is shown. The mode of winding the rectangular coil 100 of the prior art is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Coil 10a Edgewise bending part 11 Temporarily wound coil 12 Forming coil 12a Edgewise bending process part 15 Rectangular material 20 Coil forming jig 20a Circular part 20b Elliptical part 20c Polygonal part 20c1 Long side concave shape part 20c2 Short side concave part Shape part 20c3 R part 30 Circumferential coil compression means 31 Long side pressing mechanism 32 Short side pressing mechanism 40 Winding direction coil compression means 60 Winding device 61 Base 62 Winding shaft

Claims (4)

In the method of manufacturing a coil, which is formed by edgewise bending a rectangular material,
Temporary winding step of forming a temporary winding coil by temporarily winding the flat rectangular material on a cylindrical temporary winding jig, and by performing edgewise bending processing of the flat rectangular material into a substantially circular shape;
The temporary winding coil is inserted into the coil forming jig using a coil forming jig whose outer peripheral shape gradually changes from a circular shape to a polygonal shape, and the rectangular material is formed into a polygonal shape. A coil forming process for forming a wound coil;
A method for manufacturing a coil, comprising: In the manufacturing method of the coil according to claim 1,
Comprising a first coil pressing means for applying a compressive force in the winding direction of the coil during forming from the temporary coil to the square coil,
In the coil forming step, in the state where the temporarily wound coil is mounted on the polygonal portion of the coil forming jig, a compression force is applied in the winding direction by the first coil pressing means, and the square winding shape A method for manufacturing a coil, comprising forming the coil. In the manufacturing method of the coil according to claim 2,
Comprising a second coil pressing means for pressing from the circumferential direction of the coil toward the concave portion of the coil forming jig,
Before each side of the polygon of the coil forming jig is formed into a concave shape that is recessed inward, and the forming coil attached to the polygonal portion by the first coil pressing means is applied with a compressive force in the winding direction. The coil manufacturing method is characterized in that the second coil pressing means is press-molded during molding. In the manufacturing method of the coil in any one of Claims 1 thru | or 3,
The shape of the temporary winding coil is such that the peripheral length of one turn of the temporary winding coil is substantially equal to the peripheral length of one turn of the square winding coil wound around the outer periphery of the coil forming jig. And a shape of the temporary winding jig is set.

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