TWI888759B - Manufacturing method of coil component and coil component - Google Patents

Abstract

The coil component (1) of the present invention comprises a coil (10) and a core member (30) including a core portion (31) disposed inside the coil. The manufacturing method of the coil component comprises a winding step and an isostatic pressing step after the winding step. In the winding step, a winding wire (20) is wound around a core portion (31) in multiple layers to form a coil (10) having a portion in the circumferential direction having an intersection (11) where winding wire portions (21) adjacent to each other in the stacking direction cross when viewed in the stacking direction. In the isostatic pressing step, in a state where the core (31) is arranged inside the coil (10), at least the intersection (11) of the coil (10) is pressed together with the core member (30) by isostatic pressing.

Description

Manufacturing method of coil parts and coil parts

The present invention relates to a method for manufacturing a coil component having a coil and a core member including a core portion arranged inside the coil, and the coil component.

Previously, a coil formed by winding a wire into multiple layers was used in an electric machine. For example, the electric machine contains a coil part having the coil and a core member, and the core member includes a core portion arranged inside the coil. When the coil is wound into multiple layers, it is arranged in the following manner: in a portion of the circumference of the coil, the winding portion of the upper layer crosses the winding portion of the lower layer when viewed along the stacking direction. This portion is called an intersection. In a portion of the coil that is not a crossover point, the winding portion of the upper layer is arranged along the wire length direction of the winding portion of the lower layer. When the cross-sectional shape of the winding is circular, in the part of the coil that is not the intersection, the winding part of the upper layer is arranged along the groove formed by the two winding parts of the lower layer.

Patent document 1 describes a method for manufacturing a coil part for a motor. In Patent document 1, after a winding core portion (a portion of a divided stator core and a bobbin) having a circular cross-section is wound in multiple layers to form a coil, the portion of the coil other than the coil end is pressed using a die while the core portion is arranged inside the coil. The so-called coil end refers to a circumferential portion of the coil that is not arranged in the stator slot. In the case of a motor coil, generally speaking, the coil end includes a cross point. That is, in Patent document 1, it is presumed that the cross point is not pressed by the die.

[Prior Art Literature] [Patent Literature]

[Patent document 1] Japanese Patent Publication No. 2007-288983

When a coil is formed by winding a winding wire having a circular cross-sectional shape, the winding portion of the upper layer may be in line contact with the winding portion of the lower layer in the portion of the coil that is not the intersection point along the line length direction. Also, when a coil is formed by winding a winding wire having a rectangular cross-sectional shape, the winding portion of the upper layer may be in surface contact with the winding portion of the lower layer in the portion of the coil that is not the intersection point along the line length direction. On the other hand, when a coil is formed by winding a winding wire having a circular cross-sectional shape, the winding portion of the upper layer may be in point contact with the winding portion of the lower layer at the intersection point. Moreover, as shown in FIG6, when a coil 910 having a different number of turns in each layer is formed by winding a winding having a rectangular cross-sectional shape, at the intersection 911, a winding portion 912 located at the end of the coil axial direction CA among the plurality of winding portions of a certain layer sometimes contacts the winding portion 913 located at the end of the coil axial direction CA among the plurality of winding portions of the lower layer only in the form of line contact. Furthermore, the dotted line in FIG6 represents the line contact portion. In this way, the area where the winding portions of the adjacent layers at the intersection are in contact with each other is smaller than the area where the winding portions of the adjacent layers are in contact with each other at the part that is not the intersection.

When the outer circumference of the coil is pressed by the die, the outer circumference of the coil is subjected to force in only one direction. Therefore, if the intersection is pressed by the die, the force will be concentrated on the smaller area where the winding parts at the intersection are in contact with each other. As a result, the winding part that is subjected to concentrated force is easily deformed in a way that the cross-sectional area becomes smaller. In this way, the local reduction in the cross-sectional area of the winding will increase the resistance of the coil. That is, if at least the intersection of the coil is pressed by the die, it can be considered that the resistance of the coil is likely to become higher. However, it is more ideal that the resistance of the coil is lower.

The purpose of the present invention is to provide a method for manufacturing a coil part and a coil part that can press at least the cross point of the coil and reduce the resistance of the coil.

The inventors of this case conducted various tests to press at least the intersection of the coil and reduce the resistance of the coil. As a result, it was noted that when at least the intersection of the coil and the core member are pressed together by isostatic pressing in a state where a core is arranged inside the coil, the cross-sectional area of the winding will not be locally reduced, and the cross-sectional area of the winding at least at the intersection can be made larger than before pressing. In this way, the resistance of the coil can be reduced. The present invention is based on this view. Furthermore, in this specification, the cross-sectional area of the winding (or winding portion) refers to the area of the cross section of the winding (or winding portion) that is orthogonal to the length direction of the wire.

The manufacturing method of the coil parts of one embodiment of the present invention has the following structure.

The present invention is a method for manufacturing a coil component having a coil and a core member including a core portion arranged inside the coil, comprising: a winding step, which is to wind a winding wire around the core portion in multiple layers to form the coil having a cross point in a circumferential portion where adjacent winding wire portions in the stacking direction cross when viewed along the stacking direction; and an isostatic pressing step, which is to press at least the cross point of the coil together with the core member by isostatic pressing after the winding step, in a state where the core portion is arranged inside the coil.

According to this structure, at least the intersection of the coil is pressed together with the core member by isostatic pressing. Here, isostatic pressing is used for the forming of ceramics, etc., and because the pressure acts isotropically, it is a forming method that can obtain a formed body with uniform density and less directionality. If isostatic pressing is gradually applied to the coil, the density inside the coil and the core member approaches uniformity, so the internal space (the gap between the winding parts, the gap between the winding part and the core member) decreases, and the winding moves in the direction of approaching the members (winding part or core member) to each other. Therefore, the uncontacted part gradually contacts the nearby member (winding part or core member). Therefore, it is possible to suppress the concentrated force on the smaller area where the winding parts at the intersection are in contact with each other. Therefore, unlike the coil whose intersection is pressed by the mold, the cross-sectional area of the winding at the intersection will not be locally reduced.

In addition, since at least the intersection of the coil is pressed together with the core member by isostatic pressing in a state where the core is arranged inside the coil, at least the bottom layer of the winding portion at the intersection moves toward the core, and at least the top layer of the winding portion at the intersection also moves toward the core. Thus, at least the winding portion at the intersection is subjected to a compressive force in the direction of the wire length. Therefore, the cross-sectional area of the winding at least at the intersection can be made larger than before pressing. In contrast, if at least the intersection of the coil is pressed by isostatic pressing without any component disposed inside the coil, the winding portion of the uppermost layer at least at the intersection moves toward the lower layer and receives a compressive force in the direction of the length of the winding portion. However, if no component is disposed inside the coil, the winding portion moves toward the direction in which the density inside becomes uniform, so the winding portion of the lowermost layer at least at the intersection moves toward the upper layer and receives a tensile force in the direction of the length of the winding portion. As a result, the cross-sectional area of at least the winding portion of the lowermost layer at at least the intersection becomes smaller. Therefore, the coil obtained by isostatic pressing at least at the intersection in a state where a core is arranged inside the coil can increase the cross-sectional area of the winding at least at the intersection compared to the coil obtained by isostatic pressing at least at the intersection in a state where no component is arranged inside the coil.

In this way, even though at least the intersection of the coil is pressed, the cross-sectional area of the winding wire will not be locally reduced, and the cross-sectional area of the winding wire at least at the intersection can be made larger than before pressing. Therefore, the resistance of the coil can be reduced.

The manufacturing method of the coil parts of one embodiment of the present invention may have the following structure.

The core is formed of a compressible material.

Assuming that the core is formed of a non-compressible material, the core will be deformed in a manner that expands in a direction orthogonal to the axial direction of the coil due to the axial force of the coil during the isostatic pressing step. As a result, the winding portion of the bottom layer of the coil moves toward the upper layer. In contrast, since the core is formed of a compressible material, the winding portion of the bottom layer of the coil will not move toward the upper layer during the isostatic pressing step. Therefore, the cross-sectional area of the winding can be made larger than before pressing, thereby reducing the resistance of the coil.

The manufacturing method of the coil parts of one embodiment of the present invention may have the following structure.

In the isostatic pressing step, the entire circumference of the coil is pressed together with the core member by isostatic pressing while the core member is arranged inside the coil.

According to this structure, the entire circumference of the coil having the cross point is pressed together with the core member by isostatic pressing while the core is arranged inside the coil. Therefore, compared with the case where only a circumferential part of the coil including the cross point is pressed together with the core member by isostatic pressing while the core is arranged inside the coil, the portion where the cross-sectional area of the winding becomes larger can be increased. In addition, there is a case where the cross-sectional area of the winding can be further increased. Therefore, the resistance of the coil can be further reduced.

The manufacturing method of the coil parts of one embodiment of the present invention may have the following structure.

The core includes at least a portion of each of a plurality of parts arranged in a direction intersecting the axial direction of the coil and mechanically connected.

According to this structure, before the isostatic pressing step is performed, a small gap in the direction intersecting the axial direction of the coil may be generated between the plurality of parts arranged and mechanically joined in the direction intersecting the axial direction of the coil. In this case, in the isostatic pressing step, the entire circumference of the coil is pressed together with the core member by isostatic pressing in a state where the core is arranged inside the coil, so that the gap between the plurality of parts in the direction intersecting the axial direction of the coil can be reduced. In this way, the length of the core in the direction intersecting the axial direction of the coil can be shortened. Therefore, the circumference of the inner and outer circumferences of the coil can be further shortened. As a result, the cross-sectional area of the winding wire can be further increased, thereby further reducing the resistance of the coil.

The manufacturing method of the coil parts of one embodiment of the present invention may have the following structure.

The coil component has a plurality of coils, and the core member has a plurality of cores. In the winding step, a plurality of winding wires are wound around the plurality of cores in multiple layers to form the plurality of coils having the intersections in a portion of each circumference. In the isostatic pressing step, the plurality of cores are disposed inside the plurality of coils, respectively, and at least the intersections of the plurality of coils are pressed together with the core member by isostatic pressing.

According to this structure, even if at least the intersections of multiple coils are pressed simultaneously, the cross-sectional area of the winding will not be locally reduced, and the cross-sectional area of the winding in the multiple coils can be made larger than before pressing. Therefore, the resistance of the multiple coils can be reduced.

The manufacturing method of the coil parts of one embodiment of the present invention may have the following structure.

In the above-mentioned winding step, the winding wire having a circular cross-sectional shape is wound to form the above-mentioned coil.

When a coil is formed by winding a winding wire having a circular cross-sectional shape, it is easier to increase the volume of the gap between the winding parts at the intersections than when a coil is formed by winding a winding wire having a rectangular cross-sectional shape. Therefore, when at least the intersection of the coil is pressed together with the core member by isostatic pressing in a state where a core is arranged inside the coil, it is easier to make the distance that the winding part of the uppermost layer of the coil at least at the intersection moves toward the core longer than when the cross-sectional shape of the winding wire is rectangular. That is, the winding part at least at the intersection can receive a greater compressive force in the direction of the wire length than when the cross-sectional shape of the winding wire is rectangular. Therefore, the cross-sectional area of the winding wire at least at the intersection can be made larger than the case where a winding wire having a rectangular cross-sectional shape is wound to form a coil in the winding step.

The manufacturing method of the coil parts of one embodiment of the present invention may have the following structure.

The isostatic pressing performed in the isostatic pressing step uses at least one of a liquid pressure-transmitting medium, a gaseous pressure-transmitting medium, and an elastic solid pressure-transmitting medium.

The coil component of one embodiment of the present invention has the following structure.

The present invention is a coil component having a coil and a core member including a core portion arranged inside the coil. The coil is formed by winding a plurality of layers around the core portion, and the cross-sectional shape of the lead portion which is the end of the winding and not wound around the core portion is circular. The coil has a cross point at one part of the circumferential direction where the winding portions adjacent in the stacking direction cross when viewed along the stacking direction, and has a parallel region at another part of the circumferential direction where the winding portions of the upper layer are arranged along the groove formed by the winding portions of the lower layer. The core portion is not formed integrally with the coil. When the outer circumferential surface of the core has two parallel planes, the two parallel planes are in contact with the winding wire; when the outer circumferential surface of the core has two non-parallel planes instead of two parallel planes, one of the two planes of the outer circumferential surface of the core and a corner of the plane that is not an end are in contact with the winding wire, or a curved surface of the outer circumferential surface of the core and a corner of the curved surface that is not an end are in contact with the winding wire; when the cross-sectional shape of the core is circular or elliptical, more than three points including the two ends in the circumferential direction within an area of more than 180° of the outer circumferential surface of the core are in contact with the winding wire. When the outer circumference of the core has a plane, the winding is bent into a plurality of recesses arranged along the circumferential direction and recessed along the stacking direction in the portion of the outer circumferential surface of the coil that covers the plane of the core. When the cross-sectional shape of the core is circular or elliptical, the winding is bent in the coil axis direction in a portion of the coil that is neither the intersection nor the boundary between the intersection and the parallel area. In any cross section of the coil part that is orthogonal to the circumferential direction and passes through the intersection, the plurality of winding portions other than the plurality of winding portions located at the ends of the coil axis do not include winding portions having recesses that contact the adjacent winding portion at two opposite positions on the outer circumference.

According to this structure, the cross-sectional shape of the lead-out portion which is the end of the winding and not wound around the core is circular. That is, the cross-sectional shape of the winding at the time when the winding is wound around the core is circular.

Furthermore, according to this structure, the core is not formed integrally with the coil. Therefore, the core is not formed by isostatic pressing the entire circumference of the coil without any components arranged inside the coil.

Furthermore, according to this configuration, when the outer circumferential surface of the core has two parallel planes, the two parallel planes are in contact with the winding wire. When the outer circumferential surface of the core does not have two parallel planes but has two non-parallel planes, one of the two planes of the outer circumferential surface of the core and a corner of the plane that is not an end are in contact with the winding wire, or a curved surface of the outer circumferential surface of the core and a corner of the curved surface that is not an end are in contact with the winding wire. When the cross-sectional shape of the core is circular or elliptical, more than three points including both ends in the circumferential direction within an area of more than 180° of the outer circumferential surface of the core are in contact with the winding wire. Therefore, the core is not a core that is arranged inside the coil after the entire circumference of the coil is pressed by isostatic pressing without any components being arranged inside the coil.

Furthermore, according to the structure, when there is a plane on the outer circumference of the core, the winding wire is bent into a plurality of concave portions arranged along the circumferential direction and concave along the lamination direction in the portion of the outer circumferential surface of the coil covering the plane. When the cross-sectional shape of the core is circular or elliptical, the winding wire is bent in the axial direction of the coil at a portion of the coil that is neither an intersection nor a boundary between an intersection and a parallel area. Therefore, the coil is not a completely unpressed coil. Moreover, the coil is not a coil obtained by pressing only a circumferential portion of the coil except the intersection using a mold.

Furthermore, according to this structure, in any cross section of the coil part that is orthogonal to the circumferential direction and passes through the intersection, the winding parts other than the winding parts located at the ends of the coil in the axial direction do not include the winding parts having recesses in contact with the adjacent winding parts at two opposite positions on the outer periphery. Therefore, the coil is not a coil that is pressed by the mold at the intersection. Assuming that the intersection is pressed by the mold, the force will be concentrated on the part of the winding part that is in contact at the intersection, so the cross-sectional shape of the winding part at the intersection that is not the end of the coil in the axial direction is easily deformed to have recesses at two opposite positions on the outer periphery. The cross-sectional area of the winding part deformed in this way becomes smaller than the cross-sectional area of other winding parts.

Therefore, the coil component having the above-mentioned structure is a coil component obtained by isostatically pressing the entire circumference of the coil having the cross point together with the core member in a state where the core member is arranged inside the coil. Isostatic pressing is used for forming ceramics, etc., and is a forming method that can obtain a formed body with uniform density and less directionality because the pressure acts isotropically. If isostatic pressing is gradually applied to the coil, the density inside the coil and the core member approaches uniformity, so the internal space (the gap between the winding parts, the gap between the winding part and the core member) decreases, and the winding moves in a direction in which the members (winding part or core member) approach each other. Therefore, the uncontacted part gradually contacts the nearby components (winding part or core component). Therefore, it is possible to suppress the concentrated force acting on the contacting part of the winding part at the intersection. Therefore, unlike the coil whose intersection is pressed by the mold, the cross-sectional area of the winding at the intersection will not be locally reduced.

Furthermore, since the entire circumference of the coil is pressed together with the core member by isostatic pressing while the core member is arranged inside the coil, the winding portion of the lowest layer of the coil moves toward the core member, and the winding portion of the highest layer of the coil also moves toward the core member. As a result, the winding is subjected to a compressive force in the direction of the length of the wire. Therefore, the cross-sectional area of the winding can be made larger than before pressing. In contrast, if the entire circumference of the coil is pressed by isostatic pressing while no member is arranged inside the coil, the winding portion of the highest layer of the coil moves toward the lower layer and is subjected to a compressive force in the direction of the length of the wire of the winding portion. However, if there is no component inside the coil, the density inside moves in a uniform direction, so the winding part of the bottom layer of the coil moves toward the upper layer and receives a tensile force in the direction of the wire length of the winding part. As a result, the cross-sectional area of at least the winding part of the bottom layer becomes smaller. Therefore, the coil obtained by isostatic pressing the entire circumference in a state where a core is arranged inside the coil can increase the cross-sectional area of the winding compared to the coil obtained by isostatic pressing the entire circumference in a state where no component is arranged inside the coil.

In this way, even though the entire circumference of the coil with the cross point is pressed, the cross-sectional area of the winding will not be partially reduced, and the cross-sectional area of the winding can be made larger than before pressing. Therefore, the resistance of the coil can be reduced.

The coil component of one embodiment of the present invention may have the following structure.

In any cross section of the coil part that is orthogonal to the circumferential direction and passes through the intersection, each of the plurality of winding parts except the plurality of winding parts located at the ends of the coil in the axial direction is in contact with the winding part that is adjacent in the axial direction of the coil and is not at the ends of the coil in the axial direction.

At the intersection, the winding parts of the adjacent layers cross each other, and the position of the windings is easily confused. Therefore, when the intersection is pressed by a mold, the gap between the winding parts adjacent to each other in the coil axial direction at the intersection may become larger. In contrast, when the entire circumference is pressed by isostatic pressing with a core disposed inside the coil, in any cross section passing through the intersection, each of the plurality of winding parts except the plurality of winding parts at the ends of the coil axial direction can contact the winding parts adjacent to each other in the coil axial direction and not at the ends of the coil axial direction. In this way, the position disorder of the winding wire is suppressed, so the deformation of the winding wire is not easy to occur during pressing, such as the cross-sectional area of the winding wire at the intersection is locally reduced. Therefore, the resistance of the coil can be reduced.

Furthermore, depending on the purpose of the coil, the number of turns in each layer is different, so the winding part that is not at the end of the coil in the axial direction sometimes does not contact the winding part adjacent to the coil in the axial direction.

In the manufacturing method of the coil part and the coil part of the present invention, the core refers to the part arranged inside the coil. Regarding the core, the core excluding the part arranged inside the coil can be an independent part. At least a part of the core can also be inseparably integrated with a part of the core member.

In the manufacturing method of the coil part and the coil part of the present invention, the use of the coil part is not particularly limited as long as it is an electrical device. The coil part can be used in electrical devices that utilize the electromagnetic induction of the coil. The coil part can be used, for example, in the armature of a rotating motor, the magnetic body of a rotating motor, an inductor, a transformer, etc. Furthermore, a rotating motor is an electrical machine that functions as at least one of a motor and a generator. When the coil part is used in the armature of a rotating motor, the coil part can be used in a rotor or a stator. When the coil part is used in the rotor of a rotating motor, the core component of the coil part may include a rotor core, may only include a portion of the rotor core, or may not include at least a portion of the rotor core. When the coil part is used in the stator of a rotating motor, the core member of the coil part may include the stator core, may include only a portion of the stator core, or may not include at least a portion of the stator core. When the coil part is used in the armature of a rotating motor, the coil part may be used, for example, in the stator of an axial gap type rotating motor, the stator of a radial gap type inner rotor type rotating motor, or the stator of a radial gap type outer rotor type rotating motor. In the following description, the so-called stator of a rotating motor refers to the stator that serves as the armature of the rotating motor. When the coil part is used in the stator of an axial gap type rotating motor, the cross-sectional shape of the core member is, for example, a rectangle, an isosceles triangle, an isosceles trapezoid, or a fan. In this specification, the cross-sectional shape of the core refers to the shape of the cross section of the core that is orthogonal to the coil axis. When the coil component is used in the stator of a radial gap type rotating motor, the cross-sectional shape of the core is, for example, a rectangle. When the coil component is used in a transformer, the cross-sectional shape of the core member is, for example, a rectangle, a circle, a rounded rectangle, or an oval (including an ellipse). In the following description, when a rotary motor is referred to as a rotary motor, it means an axial gap type or radial gap type rotary motor. When the coil component is used in the stator of a rotary motor, the winding form of the rotary motor coil can be concentrated winding or distributed winding.

In the manufacturing method of the coil part and the coil part of the present invention, the coil part may include a core member having a plurality of core parts and a plurality of coils, and may also include a core member having a single core part and a single coil. When the coil part is used in the stator of a rotating motor and the stator has a one-piece or split stator core, the core member may, for example, include a stator core, and a plurality of insulating coil frames or a plurality of insulating papers. In this case, the coil part includes a core member having a plurality of core parts and a plurality of coils. The insulating coil frame or the insulating paper is arranged between the stator core and the coil. When the coil part is used in the stator of a rotating motor and the stator has a one-piece or split stator core, the core member may, for example, be only an insulating coil frame. In this case, the coil part includes a core member having a single core and a single coil. When the coil part is used in the stator of a rotating motor and the stator has a split stator core, the core member may also include a portion of the split stator core and a single insulating coil frame or a single insulating paper. In this case, the coil part includes a core member having a single core and a single coil. When the coil part is used in the stator of a rotating motor and the winding form of the coil of the rotating motor is distributed winding, the coil part includes a core member having multiple cores and multiple coils. In this case, one core includes two parts centered on the central axis of the rotating motor and separated in the circumferential direction.

In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the core component may include a first component including a core portion and a second component separable from the first component. The manufacturing method of the coil part of the present invention may include: a winding step, which is to wind the winding wire around the core portion of the first component to form a coil; and an assembly step, which is to connect the first component to the second component to form a core component after the winding step and before the isostatic pressing step. For example, when the coil part is used in the stator of a rotating motor, the first part can be an insulating coil frame and the second part can be a stator core.

In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the core member may have a portion that is opposite to one end of the coil in the axial direction of at least a portion of the circumference of the coil. In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the core member may have two portions that are opposite to both ends of the coil in the axial direction of at least a portion of the circumference of the coil. In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the core member may have a portion that is opposite to one end of the coil in the axial direction of the coil throughout the entire circumference. In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the core member may have two portions that are opposite to both ends of the coil in the axial direction of the coil throughout the entire circumference.

In the manufacturing method of the coil component of the present invention, the so-called pressing of at least the intersection of the coil together with the core member by isostatic pressing includes the case where the entire circumference of the coil is pressed together with the core member by isostatic pressing, and the case where a portion of the circumference of the coil including the intersection is pressed together with the core member by isostatic pressing. In the case where a portion of the circumference of the coil including the intersection is pressed together with the core member by isostatic pressing, for example, the coil can be pressed by isostatic pressing in a state where the portion of the circumference of the coil that is not pressed is covered with an outer cover. The outer cover is formed of, for example, a compressible material with high rigidity. The outer cover is fixed to the core member, for example. The outer cover does not press against the coil during the isostatic pressing step. Specifically, for example, the isostatic pressing is performed under a pressure that does not deform the outer cover. Alternatively, the outer cover is configured so that it does not contact the coil even if it is slightly deformed by the isostatic pressing force. In either case, the outer cover is configured so that during the isostatic pressing step, the pressure-transmitting medium and/or the flexible bag described below will not deform and enter between the outer cover and the coil.

In the manufacturing method of the coil component of the present invention, the so-called isostatic pressing using at least one of a liquid pressure medium, a gaseous pressure medium, and an elastic solid pressure medium refers to using at least one of a liquid pressure medium, a gaseous pressure medium, and an elastic solid pressure medium as a pressure medium that isotropically applies pressure to the coil. The so-called isostatic pressing using at least one of a liquid pressure-transmitting medium, a gaseous pressure-transmitting medium, and an elastic solid pressure-transmitting medium may be isostatic pressing using a liquid pressure-transmitting medium and a gaseous pressure-transmitting medium, isostatic pressing using a liquid pressure-transmitting medium and an elastic solid pressure-transmitting medium, isostatic pressing using a gaseous pressure-transmitting medium and an elastic solid pressure-transmitting medium, or isostatic pressing using a gaseous pressure-transmitting medium, a liquid pressure-transmitting medium, and an elastic solid pressure-transmitting medium. The so-called liquid pressure medium can be a liquid pressure medium at room temperature or a liquid pressure medium at a temperature higher than room temperature. The so-called gaseous pressure medium can be a gaseous pressure medium at room temperature or a gaseous pressure medium at a temperature higher than room temperature. The elastic solid pressure medium is preferably a solid pressure medium with rubber elasticity. The elastic solid pressure medium can be rubber or an elastic body other than rubber. When using a liquid pressure medium or a gaseous pressure medium, in the isostatic pressing step, the coil and the core member are sealed in a flexible bag. The flexible bag may be a solid pressure-transmitting medium with elasticity or may not be a solid pressure-transmitting medium with elasticity. For example, when the thickness of the flexible bag is extremely thin, the flexible bag is not a solid pressure-transmitting medium with elasticity. The flexible bag is preferably vacuum, but air may remain. The outer peripheral surface of the coil does not contact the liquid pressure-transmitting medium. The outer peripheral surface of the coil does not contact the gaseous pressure-transmitting medium. The outer peripheral surface of the coil contacts the solid pressure-transmitting medium with elasticity or the flexible bag. The so-called isostatic pressing using at least a liquid pressure medium as the pressure medium is, for example, equivalent to wet type cold isostatic pressing (WET CIP: Wet type Cold Isostatic Pressing or Wet-Bag Cold Isostatic Pressing), dry type cold isostatic pressing (DRY CIP: Dry type Cold Isostatic Pressing or Dry-Bag Cold Isostatic Pressing), or isostatic pressing using a liquid pressure medium at a temperature higher than room temperature. The so-called isostatic pressing using at least a gaseous pressure medium as the pressure medium is, for example, equivalent to hot isostatic pressing (HIP: Hot Isostatic Pressing), or isostatic pressing using a gaseous pressure medium at room temperature. Isostatic pressing using at least a solid pressure medium with elasticity as the pressure medium is equivalent to, for example, dry type cold isostatic pressing (DRY CIP: Dry type Cold Isostatic Pressing or Dry-Bag Cold Isostatic Pressing) or rubber isostatic pressing (RIP: Rubber Isostatic Pressing). In wet cold isostatic pressing (WET CIP) and dry cold isostatic pressing (DRY CIP), a liquid pressure medium at room temperature is used. In hot isostatic pressing (HIP), a high-temperature gaseous pressure medium is used. Hot isostatic pressing is a pressing process that can perform pressing and heating treatment at the same time. The temperature of the gaseous pressure medium in hot isostatic pressing can be higher than room temperature and is not particularly limited.

In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the winding wire has a conductor and an insulating film covering the outer peripheral surface of the conductor. The winding wire can be a single wire or a twisted wire. In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the winding wire portion refers to a part of the winding wire. In the manufacturing method of the coil part of the present invention and the coil part of the present invention, the stacking direction refers to the direction of the stacking of multiple layers formed by the winding wire. In this specification, the upper layer and the lower layer refer to any two layers adjacent to each other in the stacking direction among the multiple layers. The lower layer is a layer closer to the core than the upper layer. In the manufacturing method of the coil component and the coil component of the present invention, the intersection does not only refer to the position where two winding portions adjacent to each other in the stacking direction intersect when observed in the stacking direction. The intersection includes at least one winding portion of the adjacent layer that intersects with multiple winding portions of a certain layer when observed in the stacking direction. At the intersection, at least one winding portion of each layer may intersect with the winding portion of the adjacent layer when observed in the stacking direction. The coil in the manufacturing method of the coil component and the coil component of the present invention has an intersection in a part of the circumferential direction. In a part of the circumferential direction of the coil that is not the intersection, the winding portion of the upper layer is arranged along the line length direction of the winding portion of the lower layer. In the manufacturing method of the coil part and the coil part of the present invention, the coil may have two intersections or a single intersection. In the coil part of the present invention, the parallel area includes at least one winding part that is arranged along a groove formed by two winding parts of a certain layer and is higher than the winding part. In the parallel area, at least one winding part of each layer except the bottom layer may be arranged along a groove formed by two winding parts of an adjacent layer. In the coil part of the present invention, the winding method of the coil is orthocyclic winding. In the manufacturing method of the coil of the coil part of the present invention, the winding method of the coil may be orthocyclic winding. In the manufacturing method of the coil parts of the present invention, the winding method of the coil can be wild winding or helical winding.

In the manufacturing method of the coil part of the present invention, the core formed of a compressible material refers to a core formed of a compressible material having a Passon's ratio less than 0.49. In the coil part of the present invention, the core can be formed of a compressible material having a Passon's ratio less than 0.49.

In the manufacturing method of the coil parts of the present invention, the so-called multiple parts that are mechanically joined may be, for example, multiple parts joined using fastening members such as screws or bolts, or multiple parts joined by riveting. The multiple parts joined by riveting may also be, for example, multiple electromagnetic steel plates. In the manufacturing method of the coil parts of the present invention, when the core includes multiple parts arranged and arranged in a direction intersecting the coil axis and mechanically joined, the multiple parts may also be arranged in a direction orthogonal to the coil axis.

In the manufacturing method of the coil parts of the present invention, the so-called winding with a circular cross-sectional shape refers to the winding with a circular cross-sectional shape perpendicular to the length direction of the winding. In this specification, the so-called cross-sectional shape of the winding refers to the shape of the cross-sectional shape perpendicular to the length direction of the winding. In this specification, the so-called cross-sectional shape of the winding part refers to the shape of the cross-sectional shape of the winding part perpendicular to the length direction of the winding.

In the coil parts of the present invention, the so-called lead-out portion with a circular cross-sectional shape refers to the lead-out portion having a circular cross-sectional shape perpendicular to the length direction of the wire. In the coil parts of the present invention, the lead-out portion as the end of the winding wire is not connected to the portion of the winding wire other than the lead-out portion by welding, etc., but has the same structure as the portion of the winding wire other than the lead-out portion.

In the coil parts of the present invention, the core that is not integrally formed with the coil means a core that is not a core obtained by filling a mold with a hollow coil with a magnetic material and performing pressure forming. Whether the core is integrally formed with the coil can be judged by observing the shape of the outer circumference of the core. In the case where the core and the coil are integrally formed, for example, a molding material made by mixing magnetic powder and resin is solidified while entering the gap between the bottom winding parts. Therefore, in the case where the core and the coil are integrally formed, a protrusion is formed on the outer circumference of the core to be arranged in the gap between the adjacent winding parts.

In the coil parts of the present invention, the outer peripheral surface of the so-called core has two parallel planes, for example, the shape of the cross section of the core perpendicular to the coil axis is a rectangle, a rounded rectangle, a trapezoid, etc. In the coil parts of the present invention, the outer peripheral surface of the so-called core does not have two parallel planes but has two non-parallel planes, for example, the shape of the cross section of the core perpendicular to the coil axis is a triangle or a fan, etc. In the coil parts of the present invention, the so-called core with a circular or elliptical cross section refers to the core with a circular or elliptical cross section perpendicular to the coil axis.

In the coil component of the present invention, when the outer circumference of the core does not have two parallel planes but has two non-parallel planes, the outer circumference of the core may have a curved surface or may not have a curved surface. When the outer circumference of the core does not have two parallel planes but has two non-parallel planes and one curved surface, one of the two non-parallel planes and a corner of the plane that is not an end may be in contact with the winding wire, or the curved surface and a corner of the curved surface that is not an end may be in contact with the winding wire.

In the coil parts of the present invention, the situation where more than three points including both ends in the circumferential direction within an area of more than 180° on the outer circumferential surface of the core are in contact with the winding wire does not include the situation where the three or more points fall within an area less than 180° on the outer circumferential surface of the core. In the coil parts of the present invention, the so-called more than three points on the outer circumferential surface of the core are in contact with the winding wire, which means that more than three parts of the outer circumferential surface of the core separated in the circumferential direction are in contact with the winding wire. The contact can be point contact, line contact, or surface contact.

The coil component of the present invention has the following characteristics: when there is a plane on the outer circumference of the core, the portion of the outer circumference of the coil covering the plane is bent to form a plurality of concave portions arranged along the circumferential direction and concave in the stacking direction. In this case, the portion of the outer circumference of the coil covering the plane of the core is bent in the stacking direction. The so-called bending of the winding in the stacking direction in a portion of the outer circumference of the coil means that any winding portion constituting a portion of the outer circumference of the coil is bent in the stacking direction. Furthermore, in this feature, the portion of the outer circumference of the coil that covers one plane of the core refers to the portion of the outer circumference of the coil that overlaps with one plane of the core when observed along the stacking direction.

In the coil parts of the present invention, the so-called part of the coil that is neither the intersection point nor the boundary between the intersection point and the parallel area can be a parallel area or a region that is not a parallel area. The region that is not a parallel area here refers to, for example, a region that is a parallel area when the coil is formed by winding the wire and is no longer a parallel area after isostatic pressing.

The coil component of the present invention has the following characteristics: in any cross section of the coil component that is orthogonal to the above-mentioned circumferential direction and passes through the intersection, the plurality of winding parts other than the plurality of winding parts located at the ends in the axial direction of the coil do not include winding parts having concave parts that contact the adjacent winding parts at two opposite positions on the outer periphery. In this characteristic, the plurality of winding parts other than the plurality of winding parts located at the ends in the axial direction of the coil refer to the plurality of winding parts existing between the plurality of winding parts located at one end in the axial direction of the coil and the plurality of winding parts located at the other end in the axial direction of the coil. Furthermore, in this feature, the winding portion having recesses at two positions opposite to each other on the outer periphery may be, for example, a winding portion having recesses at two intersections of a straight line passing through the approximate center of the cross section of the winding portion and the outer periphery of the winding portion. Furthermore, the winding portion having recesses at two positions opposite to each other on the outer periphery may be, for example, a winding portion having two recesses such that when the cross section of the winding portion is divided into a first region including one of the two recesses, i.e., the first recess, and a second region having the same area as the first region, the other of the two recesses, i.e., the second recess, must exist in the second region, and the division cannot be performed in such a way that the second recess exists in the first region.

In the scope of the patent application, if the number of a certain constituent element is not clearly specified and the constituent element is expressed in the singular when translated into English, the present invention may have a plurality of such constituent elements. In addition, the present invention may have only one such constituent element.

Furthermore, in the present invention and embodiments, the words including, comprising, having and their derivatives are intended to include additional items in addition to the listed items and their equivalents.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification and the scope of the patent application have the same meaning as commonly understood by technicians in the field to which the invention belongs. Terms such as terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant technology and the invention, and not interpreted in an idealized or overly formalized meaning.

In this manual, the term "may also" is a non-exclusive term. "May also" means "although it is also possible to..., it is not limited to this." In this manual, "may also" implicitly includes the situation of "not performing...".

Before describing the implementation of the present invention in detail, it should be understood that the present invention is not limited to the details of the composition and configuration of the components described in the following description or illustrated in the attached drawings. The present invention may also be an implementation other than the implementation described below. The present invention may also be an implementation obtained by applying various changes to the implementation described below.

According to the manufacturing method of the coil component and the coil component of the present invention, at least the cross point of the coil can be pressed and the resistance of the coil can be reduced.

1: Coil parts

10: Coil

11: Intersection

12: Parallel area

20: Reeling

21: Winding section

21a: Winding section

22: Lead-out section

23: concave part

30: Core components

31: Core

32: Shaft collar part

33a: Plane

33b: Plane

34a: Plane

34b: Plane

34c: plane

35: Corner

36: Region

37: Plane

40: stator core

41: Insulation coil frame

42: Coil frame parts

43: Stator core parts

44: Electromagnetic steel plate

51: Pressurized container

52: Liquid pressure medium

53:bag

61: Pressurized container

62: Gaseous pressure medium

63:bag

71: Pressurized container

72: Liquid pressure medium

73: Rubber mold

74:bag

81: Pressurized container

82: Rubber mold

91: Pressurized container

92: Liquid pressure medium

93: Pressurized rubber mold

94: Rubber mold

901: Winding Department

902: concave part

910: Coil

911: Intersection

912: Reeling Department

913: Reeling Department

CA: Coil axis

P: point

FIG1 is a schematic diagram illustrating the first embodiment of the manufacturing method of the coil parts of the present invention.

FIG2 is a schematic diagram illustrating the third embodiment of the manufacturing method of the coil parts of the present invention.

FIG3 is a schematic diagram of a coil part manufactured by the fourth embodiment of the coil part manufacturing method of the present invention.

Figure 4 (a) to (j) are schematic diagrams of one implementation method (the fifth implementation method) of the coil component of the present invention.

Figures 5(a) and 5(b) are cross-sectional photographs of an embodiment of the coil part of the present invention, and Figure 5(c) is a cross-sectional photograph of a coil part of a comparative example.

Figure 6 is a diagram showing the intersection of the coils formed by winding a winding wire having a rectangular cross-sectional shape.

<First implementation method>

Referring to FIG. 1 , the first embodiment of the manufacturing method of the coil part of the present invention is described. The coil part 1 of the present embodiment has at least one coil 10 and a core member 30. The core member 30 includes at least one core 31 respectively arranged inside at least one coil 10. The number of coils 10 and cores 31 of the coil part 1 in FIG. 1 is 1 respectively, but it can also be plural. The cross-sectional shape of the core 31 in FIG. 1 is rectangular, but the cross-sectional shape of the core 31 is not particularly limited. The core 31 is formed of a compressible material.

The manufacturing method of the coil component 1 of the present embodiment includes a winding step and an isostatic pressing step. In the winding step, the winding wire 20 is wound around the core portion 31 in multiple layers to form at least one coil 10. In FIG1 , the number of layers of the coil 10 is 4, but it may be more or less than 4. The coil 10 has a cross point 11 in a portion of the circumferential direction where the winding wire portions 21 adjacent in the stacking direction cross when viewed along the stacking direction. The cross-sectional shape of the winding wire 20 in the winding step of FIG1 is circular, but the cross-sectional shape of the winding wire 20 in the winding step of the present embodiment may also be rectangular.

The isostatic pressing step is performed after the winding step. In the isostatic pressing step, in a state where the core 31 is arranged inside at least one coil 10, at least the intersection 11 of at least one coil 10 is pressed together with the core member 30 by isostatic pressing.

The isostatic pressing performed in the isostatic pressing step is isostatic pressing using at least one of a liquid pressure medium, a gaseous pressure medium, and an elastic solid pressure medium.

FIG. 1(a) shows an example of isostatic pressing using at least a liquid pressure medium. The isostatic pressing of FIG. 1(a) is, for example, wet cold isostatic pressing (WET CIP). In FIG. 1(a), the coil 10 and the core member 30 are sealed in a flexible bag 53, the bag 53 is placed in a liquid pressure medium 52 in a pressurized container 51, and then the pressure medium 52 is pressurized. However, when only a portion of the circumference of the coil 10 is pressed, the portion of the circumference of the coil 10 that is not pressed is covered in advance with an outer cover. The bag 53 is preferably vacuum, but air may remain. The bag 53 may be made of rubber or non-rubber.

FIG. 1(b) shows an example of isostatic pressing using at least a gaseous pressure medium. The isostatic pressing in FIG. 1(b) is, for example, hot isostatic pressing (HIP). The coil 10 and the core member 30 are sealed in a flexible bag 63, the bag 63 is placed in a pressurized container 61, and the gaseous pressure medium 62 in the pressurized container 61 is pressurized. However, when only a portion of the circumference of the coil 10 is pressed, the circumferential portion of the coil 10 that is not pressed is covered in advance with an outer cover. The bag 63 is preferably vacuum, but air may remain. The bag 63 may be made of rubber or non-rubber.

FIG. 1( c ) shows an example of isostatic pressing using at least a liquid pressure medium and an elastic solid pressure medium. The isostatic pressing of FIG. 1( c ) is, for example, wet cold isostatic pressing (WET CIP). A rubber mold 73 with a coil 10 and a core member 30 is sealed in a flexible bag 74, and the bag 53 is placed in a liquid pressure medium 72 in a pressurized container 71, and then the pressure medium 72 is pressurized. However, in the case where only a portion of the circumference of the coil 10 is pressed, the portion of the circumference of the coil 10 that is not pressed is covered in advance with an outer cover. The bag 74 is preferably vacuum, but air may be left in it. The rubber mold 73 is equivalent to a solid pressure-transmitting medium with elasticity. Furthermore, a rubber bag may be used to replace the rubber mold 73 and the bag 74.

FIG. 1( d ) shows an example of isostatic pressing using at least a solid pressure medium having elasticity. The isostatic pressing in FIG. 1( d ) is rubber isostatic pressing (RIP). The coil 10 and the core member 30 are arranged in a rubber mold 82 arranged in a pressure container 81, and the rubber mold 82 is directly pressurized by a piston of the pressure container 51. However, when only a part of the circumference of the coil 10 is pressed, the circumferential part of the coil 10 that is not pressed is covered in advance with an outer cover. The rubber mold 82 is equivalent to a solid pressure medium having elasticity.

FIG. 1( e ) and FIG. 1( f ) show two examples of isostatic pressing using at least a liquid pressure medium and an elastic solid pressure medium. The isostatic pressing in FIG. 1( e ) and FIG. 1( f ) is, for example, dry cold isostatic pressing (DRY CIP). The internal space of the pressurized container 91 in FIG. 1( e ) and FIG. 1( f ) is divided by a pressurized rubber mold 93 into a space for arranging a liquid pressure medium 92 and a space for arranging a forming rubber mold 94. The coil 10 and the core member 30 are arranged in the forming rubber mold 94, and are subjected to pressure from the pressure medium 92 via the forming rubber mold 94 and the pressurized rubber mold 93. When only a portion of the circumference of the coil 10 is pressed, the circumferential portion of the coil 10 that is not pressed is covered with an outer cover in advance.

Furthermore, the method of pressurizing the gaseous or liquid pressure medium in the pressurized container 51, 61, 71, 91 may be, for example, a method of pressurizing the pressure medium pressurized by a pressure booster into the pressurized container 51, 61, 71, 91, or a method of pressurizing the pressure medium by a piston of the pressurized container 51, 61, 71, 91.

According to the manufacturing method of the coil component 1 of the present embodiment, although at least the intersection 11 of the coil 10 is pressed, the cross-sectional area of the winding wire 20 will not be locally reduced, and the cross-sectional area of the winding wire 20 at least at the intersection 11 can be made larger than before pressing. Therefore, the resistance of the coil 10 can be reduced.

According to the manufacturing method of the coil component 1 of this embodiment, the following effects can be obtained. Since deformation of the winding wire 20 such as partial reduction of the cross-sectional area of the winding wire 20 will not occur, damage to the insulating film of the winding wire 20 can be suppressed.

When the intersection 11 is pressed by a mold, the gap between the winding parts 21 adjacent to each other in the coil axial direction CA at the intersection 11 may become larger. In contrast, according to the manufacturing method of the coil component 1 of the present embodiment, the position disorder of the winding 20 at the intersection 11 can be suppressed. Therefore, compared with the case where the intersection 11 is pressed by a mold, the gap between the winding parts 21 at the intersection 11 and the gap between the winding part 21 and the core part 31 at the intersection 11 can be reduced. Therefore, compared with the case where the intersection 11 is pressed by a mold, the coil component 1 can be miniaturized. In addition, compared with the case where the intersection 11 is pressed by a mold, the thermal conductivity of the coil component 1 can be improved. Furthermore, compared with the case where the intersection 11 is pressed using a mold, the leakage magnetic flux of the coil component 1 can be suppressed.

For example, as shown in FIG. 1 , the core member 30 may have two axial ring portions 32 that are opposite to both ends of the intersection 11 in the coil axial direction CA. In a state where the core 31 is disposed inside the coil 10 and the intersection 11 is disposed between the two axial ring portions 32, the intersection 11 cannot be pressed along the coil axial direction CA using a mold. Therefore, in this case, although the gap between the winding portions 21 of adjacent layers at the intersection 11 and the gap between the winding portion 21 and the core portion 31 at the intersection 11 can be made smaller than before pressing, the gap between the winding portions 21 of the same layer at the intersection 11 cannot be reduced. On the other hand, according to the isostatic pressing step of the manufacturing method of the coil component 1 of the present embodiment, even if the core member 30 has two axial ring portions 32 opposite to both ends of the coil axial CA of the intersection 11 in the coil axial direction CA, the gap between the winding portions 21 of adjacent layers at the intersection 11, the gap between the winding portion 21 and the core portion 31 at the intersection 11, and the gap between the winding portions 21 of the same layer at the intersection 11 can be made smaller than before pressing. Therefore, in the case where the core member 30 has two axial ring portions 32, the difference in thermal conductivity between the manufacturing method of the coil component 1 of the present embodiment and the case where the intersection 11 is pressed using a mold becomes greater.

Furthermore, in the present embodiment, the pressure applied when pressing at least the intersection 11 of the coil 10 together with the core member 30 by isostatic pressing is not particularly limited. The pressure applied is preferably such that the cross-sectional area of the winding 20 at least the intersection 11 of the coil 10 is larger than the pressure applied before pressing. The pressure applied may be, for example, 10 MPa or more, 20 MPa or more, or 30 MPa or more. When the conductor of the winding 20 is aluminum or an aluminum alloy, the pressure applied may be, for example, 10 MPa or more. When the conductor of the winding 20 is copper or a copper alloy, the pressure applied may be, for example, 20 MPa or more. When the cross-sectional shape of the winding wire 20 during the winding step is circular, the pressure may be a pressure to the extent that the cross-sectional shape of the winding wire 20 is maintained in a circular shape.

Furthermore, the manufacturing method of the coil component 1 of the present embodiment may also include an insulating tape winding step of winding an insulating tape around the outer peripheral surface of the coil 10 after the winding step and before the isostatic pressing step. The insulating tape may be pre-impregnated with a thermosetting resin. The insulating tape may also be impregnated with a thermosetting resin after the insulating tape is wound. The insulating tape may not be impregnated with a thermosetting resin. Both the insulating tape and the thermosetting resin have insulating properties. The thermosetting resin may be a resin that can be hardened only at a temperature higher than room temperature, or a resin that can be hardened at room temperature. By isostatic pressing, at least the intersection 11 of the coil 10 is pressed, so that the close contact between the insulating tape and the coil 10 is improved, thereby improving the insulation of the coil 10. In addition, in the isostatic pressing step, when a liquid or gaseous pressure medium with a temperature higher than room temperature is used for isostatic pressing, the hardening of the thermosetting resin can be accelerated. Furthermore, the manufacturing method of the coil component 1 of the present embodiment may not have such an insulating tape winding step.

Furthermore, in the present embodiment, when the portion of the core member 30 disposed inside the coil 10 is only the cylindrical core 31, isostatic pressing can be performed in a state where the inside of the core 31 is filled with, for example, rubber. In this way, deformation of the core 31 such as protrusion of a portion of the inner circumference of the core 31 or reduction of the inner diameter of the core 31 can be suppressed, and isostatic pressing can be applied to the inner circumference of the core 31. Furthermore, the so-called case where the portion of the core member 30 disposed inside the coil 10 is only the cylindrical core 31 refers to, for example, a case where the coil part 1 is used in a stator of a rotating motor and the core member 30 is an insulating coil frame.

<Second implementation method>

The second embodiment as an embodiment of the manufacturing method of the coil component of the present invention is described. The second embodiment has the following structure in addition to the structure of the first embodiment. In the isostatic pressing step in the manufacturing method of the coil component 1 of this embodiment, the entire circumference of the coil 10 is pressed together with the core member 30 by isostatic pressing in a state where the core 31 is arranged inside the coil 10. The pressure applied when the entire circumference of the coil 10 is pressed together with the core member 30 by isostatic pressing is not particularly limited. In the case where the cross-sectional shape of the winding wire 20 in the winding step is circular, if the pressure applied in the isostatic pressing step is gradually increased, the cross-sectional shape of the winding wire portion 21 surrounded by the six winding wire portions 21 in the circumferential direction of the coil 10 other than the intersection 11 is finally deformed into a hexagon. The pressure applied may be less than the pressure applied to deform the cross-sectional shape of the winding wire portion 21 surrounded by the six winding wire portions 21 into a hexagon. In the case where the cross-sectional shape of the winding wire 20 in the winding step is circular, the pressure applied may also be a pressure applied to the extent that the cross-sectional shape of the winding wire 20 is maintained as a circular shape.

<Implementation Method No. 3>

The third embodiment as an embodiment of the manufacturing method of the coil part of the present invention is described with reference to FIG2. In addition to the structure of the second embodiment, the third embodiment also has the following structure. The core 31 of this embodiment includes at least a portion of each of a plurality of parts arranged and mechanically connected in a direction intersecting the coil axial direction CA. The coil part 1 of FIG2 is a coil part 1 for the stator of an outer rotor type or inner rotor type rotating motor, but the use of the coil part 1 of this embodiment is not limited to this. The coil part 1 of this embodiment can also be a coil part 1 for the stator of an axial gap type rotating motor or other electrical equipment.

The core member 30 of FIG. 2 includes an insulating coil frame 41 and a stator core part 43 which is a part of the stator core. The core 31 may be a part of the insulating coil frame 41. Alternatively, the core 31 may include a part of the insulating coil frame 41 and a part of the stator core part 43 arranged inside the insulating coil frame 41. The stator core part 43 includes a plurality of electromagnetic steel plates 44. The plurality of electromagnetic steel plates 44 are arranged in a direction orthogonal to the coil axis CA. The plurality of electromagnetic steel plates 44 are mechanically joined by riveting. Specifically, the plurality of electromagnetic steel plates 44 are joined by embedding a protrusion formed on the electromagnetic steel plate 44 into a recess formed on an adjacent electromagnetic steel plate 44. The insulating coil frame 41 includes two coil frame parts 42. The stator core part 43 is arranged between the two coil frame parts 42. The arrangement direction of the two coil frame parts 42 is the same as the arrangement direction of the plurality of electromagnetic steel plates 44. The coil frame parts 42 and the stator core parts 43 may not be joined, or may be mechanically joined by riveting or the like. The core 31 of FIG. 2 includes at least a portion of each of the plurality of parts 44, 44, ‧‧‧‧ (or the plurality of parts 42, 42, 44, 44, 44‧‧‧) arranged in a direction orthogonal to the coil axis CA and mechanically joined.

Since the core 31 includes at least a portion of each of a plurality of parts arranged and mechanically joined in a direction intersecting the coil axis CA, the length of the core 31 in the direction intersecting the coil axis CA can be shortened by isostatic pressing. Therefore, the circumference of the inner and outer circumferences of the coil 10 can be further shortened. As a result, the cross-sectional area of the winding 20 can be further increased, thereby further reducing the resistance of the coil 10. In addition, the length of the core 31 and the coil 10 in the direction intersecting the coil axis CA can be shortened, so that the coil component 1 can be further miniaturized. In addition, by increasing the cross-sectional area of the winding 20, the gaps between the winding parts 21 and the gaps between the winding part 21 and the core 31 can be further reduced. Therefore, the thermal conductivity of the coil component 1 can be further improved, and the leakage magnetic flux of the coil component 1 can be further suppressed.

<Implementation Method No. 4>

The fourth embodiment as an embodiment of the manufacturing method of the coil component of the present invention is described with reference to FIG3. In addition to the configuration of at least one of the first to third embodiments, the fourth embodiment also has the following configuration. The coil component 1 of this embodiment has a core member 30 including a plurality of cores 31, and a plurality of coils 10. In the winding step in the manufacturing method of the coil component 1 of this embodiment, a plurality of winding wires 20 are respectively wound around a plurality of cores 31 in multiple layers to form a plurality of coils 10. Each coil 10 has a cross point 11 in a portion of the circumferential direction. In the isostatic pressing step of the manufacturing method of the coil component 1 of the present embodiment, in a state where a plurality of cores 31 are respectively arranged inside a plurality of coils 10, at least the intersections 11 of the plurality of coils 10 are pressed together with the core member 30 by isostatic pressing.

For example, as shown in FIG. 3 , the core member 30 of the present embodiment may also be an annular member. A plurality of core portions 31 may be arranged along the circumference of the core member 30. The coil component 1 of FIG. 3 is a coil component 1 used for the stator of an outer rotor type rotating motor, but the use of the coil component 1 of the present embodiment is not limited thereto. The coil component 1 of the present embodiment may also be a coil component 1 used for the stator of an inner rotor type rotating motor, the stator of an axial gap type rotating motor, or other electrical equipment. The core member 30 of FIG. 3 includes a stator core 40 and a plurality of insulating coil frames 41. The core portion 31 may also be a part of the insulating coil frame 41. Alternatively, the core portion 31 may also include a part of the insulating coil frame 41 and a part of the stator core 40 disposed inside the insulating coil frame 41. The structure of the core 31 may be the same as the structure of the core 31 in FIG. 2 . The stator core 40 may be a one-piece type or a split type. The stator core 40 is an annular component. A plurality of insulating coil frames 41 are arranged on the outer periphery of the stator core 40 along the circumferential direction of the stator core 40 .

When the core member 30 is an annular member, isostatic pressing can be performed in a state where the inside of the annular core member 30 is filled with rubber or the like in the isostatic pressing step. In this way, deformation of the core member 30 such as protrusion of a portion of the inner circumference of the core member 30 or reduction of the inner diameter of the core member 30 can be suppressed, and isostatic pressing can be applied to the inner circumference of the core member 30.

<Implementation Method No. 5>

The fifth embodiment of the coil component of the present invention will be described with reference to FIG4. The coil component 1 of the present embodiment has a coil 10 and a core member 30 including a core 31 disposed inside the coil 10. The coil 10 is formed by winding a plurality of layers of the winding wire 20 around the core 31. In FIG4(a), FIG4(c) to FIG4(e), the number of layers of the coil 10 is 4, but it may be more or less than 4. The end of the winding wire 20 not wound around the core 31 is called a lead-out portion 22. As shown in FIG4(b), the cross-sectional shape of the lead-out portion 22 is circular. That is, the cross-sectional shape of the winding wire 20 at the time when the winding wire 20 is wound around the core 31 is circular. In the coil component 1, the cross-sectional shape of the portion of the winding 20 other than the end portion may be circular or non-circular. However, the surface shape of the winding portion 21 constituting the outer circumference of the coil 10 is arc-shaped. As shown in FIG4(a), the coil 10 has a cross point 11 in one part of the circumferential direction where the winding portions 21 adjacent to each other in the stacking direction cross when viewed in the stacking direction. As shown in FIG4(c), the coil 10 has a parallel region 12 in another part of the circumferential direction where the winding portions 21 of the upper layer are arranged along the groove formed by the winding portions 21 of the lower layer.

The cross-sectional shape of the core 31 is not particularly limited. The core 31 is formed of a compressible material. The core 31 is not formed integrally with the coil 10. Therefore, the core 31 is not formed by isostatic pressing the entire circumference of the coil 10 without any components being arranged inside the coil 10.

For example, as shown in FIG4(f), the outer circumference of the core 31 may have two parallel planes 33a and 33b. When the outer circumference of the core 31 has two parallel planes 33a and 33b, the two planes 33a and 33b are in contact with the winding 20. Therefore, the core 31 is not a core arranged inside the coil 10 after the entire circumference of the coil 10 is pressed by isostatic pressing without any components arranged inside the coil 10. For example, as shown in FIG4(f), in a cross section orthogonal to the coil axis CA, the two planes 33a and 33b can be in contact with the winding 20. Furthermore, FIG4(f) only shows the winding portion 21 of the lowest layer in the winding 20.

For example, as shown in FIG. 4(g), the outer peripheral surface of the core 31 may have two non-parallel planes instead of two parallel planes. In FIG. 4(g), planes 34a and 34b are not parallel, planes 34b and 34c are not parallel, and planes 34c and 34a are not parallel. Although not shown in the figure, the outer peripheral surface of the core 31 may have two non-parallel planes and one curved surface instead of two parallel planes. In the case where the outer peripheral surface of the core 31 has two non-parallel planes instead of two parallel planes, one of the two non-parallel planes of the outer peripheral surface of the core 31 and the corner of the plane that is not the end contact the winding 20, or the curved surface of the outer peripheral surface of the core 31 and the corner of the curved surface that is not the end contact the winding 20. In the example of FIG. 4(g), the plane 34a and the corner 35 of the plane 34a which is not the end are in contact with the winding 20. Therefore, the core 31 is not a core arranged inside the coil 10 after the entire circumference of the coil 10 is pressed by isostatic pressing without any components arranged inside the coil 10. In a cross section orthogonal to the coil axis CA, the plane or curved surface and the corner can be in contact with the winding 20 (for example, refer to FIG. 4(g)). Furthermore, FIG. 4(g) only shows the winding portion 21 of the lowest layer in the winding 20.

For example, as shown in FIG4(h), the cross-sectional shape of the core 31 may be circular or elliptical. When the cross-sectional shape of the core 31 is circular or elliptical, three or more points P including both ends in the circumferential direction within an area 36 of more than 180° of the outer circumferential surface of the core 31 are in contact with the winding 20. Therefore, the core 31 is not a core that is arranged inside the coil 10 after the entire circumference of the coil 10 is pressed by isostatic pressing without any components being arranged inside the coil 10. For example, as shown in FIG4(h), in a cross section orthogonal to the coil axial direction CA, three or more points P including both ends in the circumferential direction within the area 36 can be in contact with the winding 20. Furthermore, FIG. 4(h) only shows the bottommost winding portion 21 of the winding 20.

For example, as shown in FIG4(i), when the outer circumference of the core 31 has a plane 37, the portion of the outer circumference of the coil 10 that covers the plane 37 is bent by the winding wire 20 to form a plurality of recesses 23 arranged in the circumferential direction and recessed in the lamination direction. Therefore, the coil 10 is not a completely unpressed coil. In addition, the coil 10 is not a coil 10 obtained by pressing only a circumferential portion of the coil 10 except the intersection 11 using a mold. The plane 37 may be, for example, the plane 33a or the plane 33b of FIG4(f). The plane 37 may also be, for example, any one of the planes 34a to 34c of FIG4(g). For example, as shown in FIG4(i), in a cross section orthogonal to the coil axial direction CA, a plurality of recesses 23 may be arranged along the circumferential direction and recessed along the lamination direction in the portion covering the plane 37 in the outer circumferential surface of the coil 10. For example, as shown in FIG4(i), the winding portion 21a of the outermost layer wound on the plane 37 may be bent in a manner to form the plurality of recesses 23.

For example, as shown in FIG4(j), when the cross-sectional shape of the core 31 is circular or elliptical, the winding 20 is bent in the coil axis CA at a portion of the coil 10 that is neither the intersection 11 nor the boundary between the intersection 11 and the parallel area 12. Therefore, the coil 10 is not a completely unpressed coil. In addition, the coil 10 is not a coil obtained by pressing only a circumferential portion of the coil 10 other than the intersection 11 using a mold. For example, as shown in FIG4(j), at a portion of the coil 10 that is neither the intersection 11 nor the boundary between the intersection 11 and the parallel area 12, a plurality of winding portions 21 arranged along the coil axis CA can be brought into contact with each adjacent winding portion 21 and bend in the coil axis CA. The plurality of winding parts 21 may be two winding parts 21 or more than three winding parts 21.

For example, as shown in Fig. 4(d) and Fig. 4(e), in any cross section of the coil part 1 that is orthogonal to the circumferential direction and passes through the intersection 11, the plurality of winding parts 21 other than the plurality of winding parts 21 located at the ends of the coil in the axial direction CA are not included in the winding parts 21 having concave parts that contact the adjacent winding parts 21 at two opposite positions on the outer periphery. Therefore, the coil 10 is not a coil obtained by die pressing at the intersection 11. Point Q in Fig. 4(e) indicates the location where the winding parts 21 of the adjacent layers at the intersection 11 are in point contact with each other. Assuming that the intersection 11 is pressed by a mold, the force will be concentrated on the point of contact of the winding portion 21 at the intersection 11, so the cross-sectional shape of the winding portion 21 at the intersection 11, which is not the axial end of the coil 10, is easily deformed to have concave portions at two opposite locations on the outer periphery. The cross-sectional area of the winding portion 21 deformed in this way becomes smaller than the cross-sectional area of other winding portions 21.

Therefore, the coil component 1 of the present embodiment is obtained by isostatically pressing the entire circumference of the coil 10 having the cross point 11 together with the core member 30 in a state where the core 31 is arranged inside the coil 10. The coil component 1 of the present embodiment can also be manufactured by the manufacturing method of the coil component 1 of the second embodiment or the third embodiment, for example. Although the entire circumference of the coil 10 having the cross point 11 is pressed, the cross-sectional area of the winding 20 does not partially decrease, and the cross-sectional area of the winding 20 can be made larger than before pressing. Therefore, the resistance of the coil 10 of the coil component 1 can be reduced. Furthermore, deformation of the winding wire 20, such as partial reduction of the cross-sectional area of the winding wire 20, will not occur, thus preventing the insulation film of the winding wire 20 from being damaged.

The coil component 1 of the present embodiment may further have the following features. For example, as shown in FIG. 4(d) and FIG. 4(e), in any cross section of the coil component 1 that is orthogonal to the circumferential direction and passes through the intersection 11, each of the plurality of winding portions 21 except the plurality of winding portions 21 located at the end of the coil axial direction CA is in contact with the winding portion 21 that is adjacent in the coil axial direction CA and is not at the end of the coil axial direction CA. In this way, the position disorder of the winding 20 is suppressed, so that deformation of the winding 20 is not likely to occur during pressing, such as the cross-sectional area of the winding 20 at the intersection 11 being partially reduced. Furthermore, the positional disorder of the winding at the intersection 11 is suppressed, so that the gap between the winding parts 21 at the intersection 11 and the gap between the winding part 21 at the intersection 11 and the core part 31 can be reduced compared to the case where the intersection 11 is pressed by a mold. Therefore, compared to the case where the intersection 11 is pressed by a mold, the miniaturization of the coil part 1, the improvement of the thermal conductivity of the coil part 1, and the suppression of the leakage magnetic flux of the coil part 1 can be achieved.

Furthermore, the outer peripheral surface of the coil 10 of the coil component 1 of the present embodiment may be covered with an insulating tape or an insulating tape and a thermosetting resin, or may not be covered.

Fig. 5(a) and Fig. 5(b) are photographs of the cross-section of the intersection of the coil parts of the two embodiments 1 and 2 of the present invention. Fig. 5(c) is a photograph of the cross-section of the intersection of the coil parts of the comparative example. The coil of the comparative example is pressed all around by a mold in a state where a core is arranged inside the coil. The coil of the embodiment 2 is isostatically pressed with a pressure higher than that of the coil of the embodiment 1. The structures of the coils before pressing of the embodiment 1, the embodiment 2 and the comparative example are the same. The coil parts of the embodiment 1, the embodiment 2 and the comparative example are cut at the intersection after the winding wire is reinforced with resin so that the winding wire does not move. As shown in FIG5(c), in the cross section of the comparative example, there is a winding portion 901 having recesses 902 at two opposite positions on the outer periphery. The two recesses 902 of the winding portion 901 are in contact with the adjacent winding portion. The winding portion 901 is a winding portion that is not at the end of the coil axial direction CA. In FIG5(c), the maximum length of the cross section of the winding portion 901 is longer than the maximum length of the cross section of the other winding portions. The reason is that the position of the winding portion 901 is moved due to pressing, and the slope of the winding portion 901 in the line length direction relative to the circumferential direction of the coil becomes larger. As shown in FIG. 5(a) and FIG. 5(b), in the cross section of the intersection of Examples 1 and 2, there is no winding portion having recesses at two opposite positions on the outer periphery.

1: Coil parts

10: Coil

11: Intersection

20: Reeling

21: Winding section

30: Core components

31: Core

32: Shaft collar part

51: Pressurized container

52: Liquid pressure medium

53:bag

61: Pressurized container

62: Gaseous pressure medium

63:bag

71: Pressurized container

72: Liquid pressure medium

73: Rubber mold

74:bag

81: Pressurized container

82: Rubber mold

91: Pressurized container

92: Liquid pressure medium

93: Pressurized rubber mold

94: Rubber mold

CA: Coil axis

Claims (11)

A method for manufacturing a coil component, characterized in that it is a method for manufacturing a coil component having a coil and a core member including a core portion arranged inside the coil, and includes: a winding step, which is to wind a winding wire around the core portion in multiple layers to form the coil having a cross point in a circumferential portion where winding wire portions adjacent in a stacking direction cross when viewed along the stacking direction; and an isostatic pressing step, which is to press at least the cross point of the coil together with the core member by isostatic pressing after the winding step, in a state where the core portion is arranged inside the coil. A method for manufacturing a coil part as claimed in claim 1, wherein the core is formed of a compressible material. A method for manufacturing a coil component as claimed in claim 1, wherein in the isostatic pressing step, the entire circumference of the coil is pressed together with the core member by isostatic pressing in a state where the core is arranged inside the coil. A method for manufacturing a coil component as claimed in claim 2, wherein in the isostatic pressing step, the entire circumference of the coil is pressed together with the core member by isostatic pressing in a state where the core is arranged inside the coil. A method for manufacturing a coil component as claimed in claim 4, wherein the core comprises at least a portion of each of a plurality of components arranged and mechanically connected in a direction intersecting the coil axis. A method for manufacturing a coil component as claimed in any one of claims 1 to 5, wherein the coil component has a plurality of coils including the coil, the core member has a plurality of cores including the core member, in the winding step, a plurality of winding wires are wound around the plurality of cores in multiple layers to form the plurality of coils having the intersections in a portion of each circumference, and in the isostatic pressing step, in a state where the plurality of cores are respectively arranged inside the plurality of coils, at least the intersections of the plurality of coils are pressed together with the core member by isostatic pressing. A method for manufacturing a coil part as claimed in any one of claims 1 to 5, wherein in the winding step, a winding wire having a circular cross-sectional shape is wound to form the coil. A method for manufacturing a coil component as claimed in claim 6, wherein in the winding step, a winding wire having a circular cross-sectional shape is wound to form the coil. A method for manufacturing a coil part as claimed in any one of claims 1 to 5, wherein the isostatic pressing performed in the isostatic pressing step uses at least one of a liquid pressure-transmitting medium, a gaseous pressure-transmitting medium, and an elastic solid pressure-transmitting medium. A coil component, characterized in that: it has a coil and a core member including a core portion arranged inside the coil, and the coil is formed by winding a plurality of layers around the core portion, the cross-sectional shape of the lead portion which is the end of the winding and not wound around the core portion is circular, the coil has a cross point at one part of the circumferential direction where the winding portions adjacent in the stacking direction cross when viewed along the stacking direction, and has a parallel region at another part of the circumferential direction where the winding portions of the upper layer are arranged along the groove formed by the winding portions of the lower layer In the case where the core is not formed integrally with the coil, when the outer peripheral surface of the core has two parallel planes, the two parallel planes are in contact with the winding wire, and when the outer peripheral surface of the core does not have two parallel planes but has two non-parallel planes, one of the two planes of the outer peripheral surface of the core and a corner of the plane that is not an end are in contact with the winding wire, or a curved surface of the outer peripheral surface of the core and a corner of the curved surface that is not an end are in contact with the winding wire, and the outer peripheral surface of the core The winding wire is in contact with a flat surface or a curved surface of the circumference and a corner of the flat surface or the curved surface which is not an end. When the cross-sectional shape of the core is circular or elliptical, the winding wire is in contact with more than three points including both ends in the circumferential direction within an area of more than 180° of the outer circumferential surface of the core. When the outer circumferential surface of the core has a flat surface, the winding wire is bent in a portion of the outer circumferential surface of the coil covering the flat surface of the core so as to be arranged in the circumferential direction and to have a depression in the stacking direction. When the cross-sectional shape of the core is circular or elliptical, the winding is bent in the axial direction of the coil at a portion of the coil that is neither the intersection nor the boundary between the intersection and the parallel area. In any cross section of the coil part that is orthogonal to the circumferential direction and passes through the intersection, the winding parts other than the winding parts located at the ends of the coil in the axial direction do not include the winding parts having the concave parts that contact the adjacent winding parts at two opposite positions on the outer periphery. As in claim 10, in any cross section of the coil part that is orthogonal to the circumferential direction and passes through the intersection, each of the plurality of winding parts except the plurality of winding parts located at the ends of the coil in the axial direction is in contact with the winding part that is adjacent in the coil axial direction and is not at the ends of the coil in the axial direction.