JP2013138266A - Method of manufacturing coil for reactor, and reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil having a uniform cross-sectional shape, a coil mold body including the coil, a reactor including the coil and the coil mold body, and a method of manufacturing the coil.SOLUTION: The coil includes a plurality of turns formed by spirally winding a winding 1w whose conductor cross-section is rectangular. Each turn includes straight parts 11 in each of which the winding 1w is linearly arranged, and curved parts 12 connected to the straight parts 11 and curved. An end face of the coil has a rectangular frame-like shape, and each corner is rounded. The cross-sectional shape of the straight parts 11 is identical to that of the curved parts 12, and rectangular. A space between a pair of swingable cylindrical rollers 51a, 51b is changed, and the winding 1w is made to pass therethrough. The winding 1w is deformed into a cross-sectionally trapezoidal shape by being made to pass through the space between the cylindrical rollers 51a, 51b brought into an inclined state, and bent by using the side having a smaller thickness as an inner peripheral side of the bending to form the curved parts 12. The straight parts 11 are formed by making the winding pass through the space between the cylindrical rollers 51a, 51b brought into a parallel state.

Description

  The present invention relates to a coil formed by winding a winding spirally, a method for manufacturing the coil, a coil molded body having the coil, the coil and the coil molded body, and mounted on a vehicle such as a hybrid automobile. The present invention relates to a reactor used for a component of a converter. In particular, the present invention relates to a coil having a uniform cross-sectional shape and a manufacturing method thereof.

  Conventionally, a coil formed by winding a winding in a spiral shape has been used for parts in various fields. For example, in a reactor used for a component of a converter mounted on a vehicle such as a hybrid vehicle, a winding (covered rectangular wire) having an enamel coating on the outer periphery of a rectangular wire having a rectangular conductor cross section is edgewise. An edgewise coil formed by winding is used (see Patent Document 1). The edgewise coil is more compact than a coil in which a round wire having a circular conductor cross section is wound, and can contribute to a reduction in the size of the reactor. The reactor described in Patent Document 1 is a coil having a shape suitable for the outer shape of the rectangular parallelepiped magnetic core on which the coil is arranged, specifically, a linear portion in which the winding is linearly arranged, and the linear portion. A coil having a curved portion arranged in a curved shape and having an end face shape of a rectangular frame with rounded corners (hereinafter referred to as a corner R coil).

JP 2007-173628 A

  However, in the conventional angle R coil, the portion located on the inner circumferential side of the bending in the winding constituting the bending portion is in a swelled state compared to the outer circumferential side of the bending, and the cross-sectional shape of the linear portion of the coil, There exists a problem that the cross-sectional shape of a curved part differs.

  This will be described in more detail based on FIG. For each of the straight portion 110 and the curved portion 120 of the conventional rectangular R coil 100 formed by the winding 100w having a rectangular conductor cross section, the transverse cross section of the winding 100w (straight portion 110: XX cross section, curved portion 120: YY) When the cross section is taken, the cross sectional shape of the straight portion 110 is rectangular as shown in FIG. 8 (II), and the original cross sectional shape of the winding 100w used for forming the coil 100 is maintained.

  On the other hand, when the winding 100w is bent to form the curved portion 120, the inner peripheral portion of the bending is compressed in the winding 100w as indicated by the black arrow in FIG. 8 (I), and the outer peripheral portion of the bending is pulled. It is done. Therefore, the winding constituting the bending portion 120 has a thick inner peripheral portion of the bend and a thin outer peripheral portion of the bend, and its cross-sectional shape is from the inner peripheral side of the bend as shown in FIG. It becomes a trapezoid whose thickness is reduced toward the outer peripheral side. When the step of crushing the bulge of the inner part of the winding bend is added, as shown in Fig. 8 (IV), the inner part of the winding bend is rectangular and the outer part of the bend is trapezoidal It becomes a variant. In any case, the inner peripheral side portion of the bending portion 120 is thicker than the outer peripheral side portion.

  Since the inner peripheral side portion of the bending portion is thick as described above, it is necessary to design the insulation distance between adjacent turns based on the distance between the inner peripheral side portions. As a result, the length of the coil in the axial direction is increased, which leads to an increase in the size of the coil and, in turn, an increase in the size of the coil component such as a reactor including the coil.

  Accordingly, one of the objects of the present invention is to provide a small-sized coil which is a square R coil. Another object of the present invention is to provide a coil manufacturing method capable of manufacturing a coil in which the cross-sectional shape of the straight portion and the cross-sectional shape of the curved portion are equal. Furthermore, the other object of this invention is to provide the coil molded object which has the said coil. In addition, the other object of this invention is to provide the reactor which provides the said coil and a coil molded object.

  The coil of the present invention comprises a plurality of turns formed by spirally winding a winding having a rectangular conductor cross section. Each of the turns includes a straight portion in which the winding is linearly arranged, and a curved portion in which the winding is connected to the straight portion and curved. In addition, in this coil, the thickness of the straight portion constituting each turn is substantially the same. Further, when the coil has a cross section of the winding at each of the straight portion and the curved portion constituting each turn, the coil has substantially a sectional shape of the straight portion and a sectional shape of the curved portion. Is the same.

The coil of the present invention having the above-described configuration can be manufactured, for example, by the following method for manufacturing a coil of the present invention. In the coil manufacturing method of the present invention, a winding having a rectangular conductor cross section is spirally wound, a straight portion in which the winding is arranged in a straight line, and the winding connected to the straight portion is curved. The present invention relates to a method of manufacturing a coil including a curved portion arranged in the following manner, and includes the following linear portion forming step and curved portion forming step.
[Straight line forming process]
A pair of cylindrical rollers are arranged so that the axial directions of the rollers are parallel to each other. A wire having a rectangular conductor cross section is inserted between the two cylindrical rollers. A wire rod having a substantially unchanged cross-sectional shape coming out between the cylindrical rollers is used as a winding, and the winding is conveyed linearly to form the linear portion.
[Formation process of curved part]
The two cylindrical rollers are arranged so that the interval between the cylindrical rollers becomes wider from one end side to the other end side of the two cylindrical rollers. In this state, a wire having a rectangular conductor cross section is inserted between the cylindrical rollers. Then, a wire having a trapezoidal cross section, which comes out from between the cylindrical rollers and has a thickness increasing from one end side to the other end side, is used as a winding, and the thin side of the winding is the bending side. The winding is bent to form the curved portion so as to be on the circumferential side.

  In the coil of the present invention, as described above, the thicknesses of adjacent turns formed by one continuous winding are substantially equal, and the cross-sectional shape of the straight portion and the cross-sectional shape of the curved portion are substantially equal. . That is, in the coil of the present invention, the thickness and the cross-sectional area of the winding constituting each turn are uniform. Therefore, the insulation distance between adjacent turns can be defined based on the distance between the turns at any part of the coil. That is, in the coil of the present invention, the distance between adjacent turns at an arbitrary location is uniform. Therefore, in the conventional corner R coil in which the insulation distance is designed based on the distance between the inner peripheral portions of the curved portion, the distance between the outer peripheral portions of the curved portion is longer than the distance between the inner peripheral portions. On the other hand, the coil of the present invention is small, and the coil of the present invention has a short length in the axial direction of the coil as compared with the conventional square R coil.

  In addition, according to the coil manufacturing method of the present invention, a small coil having the uniform cross-sectional shape can be easily manufactured using one continuous wire. In particular, by appropriately changing the interval between the cylindrical rollers, the degree of deformation of the wire rod by the rollers can be easily changed. Therefore, according to the manufacturing method of the present invention, it is possible to easily cope with various conditions such as the thickness of the wire and the bending diameter of the coil, and it is possible to manufacture a square R coil having a uniform cross-sectional shape. Here, as a means for transforming a wire having a rectangular conductor cross section into a wire having a trapezoidal conductor cross section, it is conceivable to use a truncated cone roller. However, when a truncated cone-shaped roller is used, it is necessary to prepare a plurality of truncated cone-shaped rollers according to the degree of deformation of the wire and replace them appropriately. On the other hand, according to the manufacturing method of the present invention, it is only necessary to appropriately change the interval and inclination between the cylindrical rollers. Compared with the case of using a truncated cone-shaped roller, the angle R coil of various specifications Can be manufactured with high productivity.

  In the coil of the present invention, the thickness of the linear portion constituting each turn is substantially the same. The thickness of the winding is measured at an arbitrary position of the linear portion constituting each turn, and the maximum value and the minimum value thereof are measured. Satisfy the difference of 0.3mm or less (including 0 (zero)). For simplicity, it is assumed that the thickness of each linear portion constituting one side surface of the outer peripheral surface of the coil is measured, and the difference between the maximum value and the minimum value of the measured values satisfies the above range.

  In the coil of the present invention, the cross-sectional shape of the straight portion and the cross-sectional shape of the curved portion are substantially the same, for example, by taking both cross-sections and taking the difference in area of both cross-sections, It is mentioned that the ratio of the difference in the area with respect to the above satisfies 3% or less (including 0 (zero)). Cross-section superposition and calculation of the ratio can be easily performed, for example, by performing image processing on the cross-sectional image. In particular, when the cross-sectional shapes of the straight part and the curved part are both rectangular, the cross section is taken and the difference between the short side of the straight part and the short side of the curved part is 0.2 mm or less (0 (zero ) And the difference between the long side of the cross section of the straight portion and the long side of the cross section of the curved portion satisfies 0.1 mm or less (including 0 (zero)), the cross-sectional shape of the straight portion and the curved portion It is assumed that the cross-sectional shape is substantially equal.

  The coil of the present invention is formed by one continuous winding (single wire), and this winding typically includes a conductor having a rectangular cross section and an insulating layer covering the outer periphery of the conductor. For example, the winding itself has a rectangular cross section. In manufacturing such a coil of the present invention, the manufacturing method of the present invention uses one continuous wire (single wire).

  A typical form of the coil of the present invention is an edgewise coil in which a winding conductor is formed of a flat wire and the winding is edgewise wound.

  Examples of the conductor having a rectangular cross section include a trapezoidal shape and a square shape, but a rectangular rectangular wire is typical. The edgewise coil is easy to increase the space factor compared to a winding having a circular conductor cross section, and is small. In order to form an edgewise coil, in the manufacturing method of the present invention, as the rectangular wire inserted between the cylindrical rollers, a conductor made of a rectangular wire can be used.

  As another form of the coil of the present invention, a coil molded body including the coil of the present invention and an inner resin portion that holds the shape of the coil can be cited.

  Since the shape of the coil is held by the inner resin portion, the coil does not expand and contract, and the coil is easy to handle. Therefore, the coil molded body is excellent in workability when, for example, the reactor is assembled. In addition, since the coil of the present invention has a uniform spacing between adjacent turns as described above, each coil molded body has a configuration in which the constituent resin of the inner resin portion is interposed between the turns. The thickness of the constituent resin present between the turns can be made uniform. Furthermore, the presence of the constituent resin of the inner resin portion between the turns can further improve the insulation between adjacent turns and make the insulation characteristics uniform.

  Examples of the coil component including the coil of the present invention include a reactor including the coil of the present invention and an annular magnetic core on which the coil is disposed. In addition, as a coil component including the coil molded body of the present invention, a reactor including the coil molded body of the present invention and an annular magnetic core on which the coil molded body is disposed may be mentioned.

  According to the reactor of the present invention, by providing the coil of the present invention and the coil molded body of the present invention that are small, the length of the magnetic core where the coil and the coil molded body are disposed (the length in the axial direction of the coil). Can be shortened. In the coil of the present invention, the size in the direction orthogonal to the axial direction is uniform from the one end side of the coil toward the other end side along the axial direction of the coil. The reactor of the present invention including the coil of the present invention and the coil molded body of the present invention is short in size in both the axial direction of the coil and the direction orthogonal to the axial direction, and is small. Such a small reactor can be suitably used for components that require a small installation space, such as in-vehicle components.

  In the coil manufacturing method of the present invention, the method further comprises a step of drawing a round wire having a circular conductor cross section to form a wire having a rectangular cross section. Following the formation of the rectangular wire, the circle is formed. The rectangular wire can be inserted between the columnar rollers.

  As a wire rod inserted between the cylindrical rollers, a rectangular wire rod having a conductor made of a flat wire or the like may be separately prepared, and the rectangular wire rod may be inserted into the cylindrical roller. However, in this case, it is necessary to align the produced rectangular wire around the bobbin, and it is necessary to traverse the bobbin so that the wire rod is not wrinkled when it is fed out from the bobbin. It takes. On the other hand, the round wire is formed into a rectangular wire, and subsequently inserted between the cylindrical rollers, so that the winding or the like can be made unnecessary, but the straight portion has high straightness. A coil can be formed.

  The coil of the present invention can be reduced in size because the cross-sectional shape of the straight portion and the cross-sectional shape of the curved portion are substantially equal and the thickness is uniform. The manufacturing method of the coil of the present invention can be suitably used for manufacturing the coil of the present invention. In addition to being small in size, the coil molded body of the present invention can contribute to improvement in the assembly workability of the reactor when it is used as a constituent element of the reactor. The reactor of the present invention is small.

FIG. 1 (I) is a schematic perspective view of the coil of the first embodiment, and FIG. 1 (II) is a front view of the coil as viewed from the end face side. FIG. 2 (I) is a schematic explanatory view explaining the process of manufacturing the coil of Embodiment 1, FIG. 2 (II) is a cross-sectional explanatory view explaining the process of forming a straight portion, FIG. 2 (III), It is sectional explanatory drawing explaining the process of forming a curved part. FIG. 3 is a schematic explanatory view illustrating a step of winding the coil according to the first embodiment. FIG. 4 is a schematic perspective view of a reactor including the coil according to the second embodiment. FIG. 4 (I) is a combination of a coil and a magnetic core, and FIG. 4 (II) is an outer side of the outer periphery of the combination. The example which provides the resin part is shown. FIG. 5 is a schematic perspective view of a reactor including the coil molded body of Embodiment 3, showing a state in which a part of the outer resin part is cut out and a part of the combined body is exposed. FIG. 6 (I) is a schematic perspective view of a coil molded body of Embodiment 3, and FIG. 6 (II) is a schematic perspective view of a coil included in the coil molded body. FIG. 7 is an exploded perspective view for explaining the assembly procedure of the combined body of the coil molded body and the magnetic core according to the third embodiment. 8 (I) is an explanatory view showing a part of a conventional angular R coil, FIG. 8 (II) is a schematic cross-sectional view of a straight portion, and FIGS. 8 (III) and (IV) are cross-sectional schematic views of a curved portion. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same names.

(Embodiment 1)
Hereinafter, an embodiment of a coil of the present invention and a method of manufacturing the coil of the present invention for manufacturing the coil will be described with reference to FIGS.

[overall structure]
The coil 1 includes a plurality of turns formed by spirally winding one continuous winding 1w. Each turn includes a straight portion 11 in which the winding 1w is linearly arranged, and a curved portion 12 connected to the straight portion 11 and in which the winding 1w is curved. That is, as shown in FIG. 1 (II), the coil 1 is a corner R coil having a rectangular frame shape and rounded corners. The most characteristic feature of the coil 1 is that the cross-sectional shape of the straight portion 11 and the cross-sectional shape of the curved portion 12 are equal. This will be described in more detail below.

[Winding]
Winding 1w includes a conductor (width 7.2 mm, thickness 2.4 mm) made of rectangular copper wire having a rectangular cross section, and an insulating layer (here enamel coating, thickness 50 μm) covering the outer periphery of the conductor. It is a covered rectangular wire. The winding 1w is formed by drawing a coated round wire having an enamel coating on the outer periphery of a conductor made of a round copper wire having a circular cross section as will be described later. The cross section of is also rectangular.

[Linear and curved parts]
Each turn constituting the coil 1 includes four straight portions 11 arranged so as to form a rectangular frame and four curved portions 12 connecting the adjacent straight portions 11. The four straight portions 11 include a pair of short side portions 11s arranged opposite to each other and a pair of long side portions 11l longer than the short side portions 11s arranged opposite to each other.

  For each long side 11l constituting one side of the outer peripheral surface of the coil 1, one straight line parallel to the axial direction of the coil is drawn, and the thickness on this straight line is measured. And the difference is 0.2 mm or less. Further, when the thickness was measured in the same manner for each short side portion 11s constituting another side surface, the difference between the maximum value and the minimum value was 0.2 mm or less, which is substantially equal to the thickness of the long side portion 11l. equal. Therefore, it can be said that all the four straight portions 11 constituting each turn have substantially the same thickness, and the thickness of the straight portions 11 of all the turns included in the coil 1 is substantially equal. Further, when the thickness was measured in the same manner for each curved portion 12 constituting the curved surface of the outer peripheral surface of the coil 1, the difference between the maximum value and the minimum value was 0.2 mm or less, and the long side portion 11l Is substantially equal to the thickness of Accordingly, it can be said that the thicknesses of the windings constituting all the turns constituting the coil 1 are substantially equal.

Furthermore, the long side portion 11l as shown in FIG. 1 (II) with x _l -x _l cutting, x _l -x _l cross sectional shape when taken cross section of the winding in the long side portion 11l, The cross-sectional shape of the x _s -x _s section when the short side part 11 _{s is} cut by x _s -x _s and the cross section of the winding is taken at the short side part 11 _s is rectangular. That is, the x _l -x _l cross section and the x _s -x _s cross section have the same shape, and are equal to the transverse cross section of the end portion of the winding 1w (a portion that is not wound and does not form a turn).

Then, as shown in FIG. 1 (II), when the bending portion 12 is cut by yy and a cross section of the winding is taken at the bending portion 12, the cross-sectional shape of the yy cross section is also rectangular. And, to the cross-sectional area of the x _l -x _l section of the linear portion (or x _s -x _s cross-section), x _l -x _l sectional (or x _s -x _s cross-section) of the yy cross-section of the cross-sectional area the curvature of the The ratio of the difference from the cross-sectional area is 3% or less. From this, it can be said that the yy cross-section is substantially equal to the cross-sectional shape (x ₁ -x ₁ cross-section, x _s -x _s cross-section) of the straight line portion 11.

  From the above, in the coil 1, the thickness of the winding wire constituting each turn is uniform throughout, and the cross-sectional shape thereof is also uniform.

[Coil manufacturing method]
The coil 1 having a uniform thickness and cross-sectional shape as described above can be manufactured by using the coil manufacturing apparatus 50 shown in FIGS. First, the coil manufacturing apparatus 50 will be described.

<Coil manufacturing equipment>
This device 50 includes a supply 53 that feeds the wound winding material 10w, a roller die portion 52 that forms a winding 1w having a predetermined shape by drawing the drawn winding material 10w, A swinging roller part 51 having a pair of cylindrical rollers 51a and 51b arranged opposite to each other in the thickness direction of the winding 1w so as to sandwich 1w, and the winding 1w passing through the swinging roller part 51 in a spiral shape A winding portion 54 (FIG. 3) that forms a coil by winding is provided.

  The winding material 10w is a single continuous wire, and is a coated round wire including a conductor made of a round copper wire having a circular cross section and an insulating layer (enamel coating) covering the outer periphery of the conductor. A round copper wire is enamel-coated to form a coated round wire, which is then wound around a supply drum of supply 53. For the winding material, the conductor cross-sectional area, the type of insulation layer, the thickness, and the like may be selected according to the specifications of the winding 1w. Further, the supply 53 can use a commercially available apparatus used for feeding the wire.

  The roller die portion 52 is a member for transforming the winding material 10w into a winding 1w having a rectangular cross section, and a pair of longitudinal roller dies 52a, which are arranged to face each other so as to sandwich the winding material 10w, 52b and lateral roller dies 52c, 52d. As such a roller die portion 52, various commercially available apparatuses used when forming a round wire into a flat wire can be used. For example, a flat wire is formed by a pair of horizontal roller dies in which a] -shaped groove is formed, and a vertical roller die and a horizontal roller die are combined at the same position.

  The most characteristic feature of the device 50 is that it includes a swing roller 51. The swing roller unit 51 is a state in which a pair of cylindrical rollers 51a and 51b are arranged so that the axial directions of the rollers 51a and 51b are parallel to each other and separated by a predetermined distance (see FIG. 2 (II), hereinafter This arrangement state is called a parallel state). Further, both cylindrical rollers 51a and 51b can be swung by a roller driving unit (not shown), and as shown in FIG. 2 (III), the distance between both rollers 51a and 51b is one end side (the left side in FIG. 2 (III)). ) To the other end side (right side in FIG. 2 (III)). That is, the oscillating roller 51 is also used in a state where the distance between the rollers 51a and 51b is widened from one end side to the other end side (hereinafter, this arrangement state is referred to as an inclined state) as described above. The

  More specifically, the rocking roller portion 51 is used in a parallel state when forming the linear portion 11, and is used in an inclined state when forming the curved portion 12.

  Further, the device 50 includes a winding length measuring unit (not shown) that measures the length of the winding 1w that has passed between the cylindrical rollers 51a and 51b. Then, when the roller drive unit receives information (signal) that the winding 1w has been sent out by a predetermined length by the winding length measuring unit, both rollers are in a parallel state or an inclined state according to the information. 51a and 51b are driven. The winding length measurement unit measures the winding length by calculation from, for example, a commercially available non-contact sensor, the number of rotations of the guide roller that assists the winding of the winding, and the guide roller specifications (peripheral length, etc.) Possible arithmetic units can be used. The apparatus 50 is configured so that the acquisition information of the winding length measuring unit is sent to the roller driving unit.

  In addition, the device 50 includes a storage unit that stores a setting value (not shown), an input unit that inputs the setting value and the like to the storage unit, a comparison determination unit that compares the setting value and the measured value, and an instruction unit that issues an instruction to each unit Control means including The length of the linear part 11 and the length of the bending part 12 designed in advance are inputted into the storage part using the input part. The comparison determination unit compares and determines the set value called from the storage unit and the measurement result of the winding length measurement unit. The command unit issues a command to the roller drive unit based on the determination result, and changes the arrangement state of the cylindrical rollers 51a and 51b. Such a control means can utilize a commercially available computer, for example.

  The winding portion 54 is a work portion for winding the winding 1w in a spiral shape, and as shown in FIG. 3, when winding the winding 1w, the winding portion 54 is arranged on the inner peripheral side of the bending and becomes a round center. The rod core portion 54a, the bending portion 54b that presses the winding 1w against the circumferential surface of the round rod core portion 54a and bends the winding 1w along the circumferential surface of the round rod core portion 54a, and the bending drive that drives the bending portion 54b. Part (not shown). Then, the device 50 has the shape of the winding 1w sent from the swinging roller portion 51 so that the winding portion 54 can perform the winding work according to the shape of the winding 1w that has passed through the cylindrical rollers 51a and 51b. Accordingly, a bending control section (not shown) for driving the bending section 54b is provided. The bending control unit controls the bending driving unit to drive the bending unit 54b based on the information of the winding 1w that has passed through the swing roller unit 51. As shown in FIG. 3, it is preferable that the length of the bent portion 54b is longer than the length of the portion where the linear portion 11 is formed in the winding 1w, because the winding 1w can be bent stably and accurately.

  In addition, the winding portion 54 is a feed portion (not shown) that feeds the winding 1w to the round rod core portion 54a side, and the winding 1w is wound in the axial direction of the coil so that the winding 1w is spirally wound. In order to shift the position little by little, a holding part (not shown) for holding the winding 1w is provided. The basic configuration of the winding unit 54 is the same as that of a commercially available winding device, and a commercially available winding device can be used.

  A procedure for forming the coil 1 using the coil manufacturing apparatus 50 having the above configuration will be described.

  First, the winding material 10w made of a coated round wire is unwound from the supply 53 and sent to the roller die portion 52, and is drawn by the vertical roller dies 52a and 52b and the horizontal roller dies 52c and 52d. A winding 1w made of a flat wire is formed.

  The winding 1w that has passed through the roller die portion 52 is subsequently fed between a pair of cylindrical rollers 51a and 51b constituting the swing roller portion 51, and is passed between both rollers 51a and 51b. When passing the portion where the linear portion 11 is formed in the winding 1w, the roller driving portion makes the swinging roller portion 51 in a parallel state, and the linear portion 11 designed in advance between the cylindrical rollers 51a and 51b in the parallel state. Only the length of (here, only the length including the extra length in the long side part) is inserted. At this time, as shown in FIG. 2 (II), the winding 1w passes between the cylindrical rollers 51a and 51b with the cross section maintained in a rectangular shape.

  As shown in FIG. 3 (I), the winding 1w that forms the linear portion 11 (mainly the long side portion) that has passed between the cylindrical rollers 51a and 51b is wound on the downstream side of the oscillating roller portion 51. It is sent to the section 54 in a straight line. If the device 50 includes a linear guide portion (not shown) between the swing roller portion 51 and the winding portion 54, the linearity of the winding 1w that has passed through the swing roller portion 51 is maintained well. can do. By being conveyed linearly in this way, the cross section of the linear portion 11 of the obtained coil 1 can maintain a rectangular shape.

  In the winding 1w, the place where the curved portion 12 connected to the straight portion 11 (long side portion) is formed is such that the swing roller portion 51 is inclined by the roller driving portion, and the cylindrical rollers 51a and 51b in the inclined state are interposed. The length of the curved portion designed in advance is inserted. At this time, the winding 1w is deformed by being pressed by the two cylindrical rollers 51a and 51b, and has a trapezoidal cross section as shown in FIG. 2 (III).

  When the winding 1w forming the bending portion 12 that has passed between the cylindrical rollers 51a and 51b is sent to the winding portion 54, the bending portion 54b driven by the bending driving portion as shown in FIG. Is bent along the peripheral surface of the round bar core portion 54a. At this time, in the winding 1w transformed into a trapezoidal shape, the swinging state of the swinging roller portion 51 is controlled so that the thinner one is the inner periphery side of the bend and the thicker one is the outer periphery side of the bend. Keep it. When such a winding 1w is bent, the inner peripheral side of the bend is compressed and swells in the thickness direction, and the outer peripheral side of the bend is pulled and becomes thin. However, the winding 1w is preliminarily deformed into a trapezoidal shape as described above in anticipation of the bulging due to compression on the inner peripheral side and the thinning due to the tension on the outer peripheral side. The shape of the cross section of the curved portion 12 is the same rectangular shape as that of the straight portion 11. In order to reduce the lifting of the winding 1w when the winding 1w is bent, the device 50 may be provided with a pressing portion (not shown) between the swing roller portion 51 and the winding portion 54. Good.

  Subsequent to the formation of the curved portion 12, the straight portion 11 (short side portion) is formed. At this time, the roller drive unit returns the swinging roller unit 51 to the parallel state, and the bending drive unit returns the bending unit 54b to the original position (FIG. 3 (III)) and winds the swinging roller unit 51 in the parallel state. The wire 1w is allowed to pass through a predetermined length (here, only the length of the short side portion) and is sent to the winding portion 54 side in a straight state as it is.

  Next, a curved portion 12 connected to the straight portion 11 (short side portion) is formed in the winding 1w. At this time, the winding 1w is passed through the rocking roller 51 in the inclined state as described above by a predetermined length and sent to the winding portion 54, where the winding 1w is transformed into a trapezoidal shape as shown in FIG. As shown in (IV), it is bent by the bent portion 54b. When the bending portion 12 is formed, the bending portion 54b is returned to the original position as described above (FIG. 3 (V)), and the swing roller portion 51 is returned to the parallel state.

  Hereinafter, as described above, the swing roller portion 51 is appropriately changed to a parallel state or an inclined state, and an operation of deforming a partial cross-sectional shape of the winding 1w sent to the winding portion 54 from a rectangular shape to a trapezoidal shape. By repeating the winding in accordance with the cross-sectional shape, a rectangular frame-like coil whose end face shape is rounded as shown in FIG. 3 (VIII) is obtained. In FIG. 3, only one turn is shown, but by repeating the above steps, turns are sequentially formed from the back to the front of the page, and a coil 1 (FIG. 1) having a plurality of turns is obtained. . FIG. 2 (I) shows the intermediate 10 in the middle of manufacturing the coil 1, and after forming a predetermined number of turns, the winding 1w is cut by a cutting portion (not shown) provided in the device 50 or the like. Thus, the coil 1 (FIG. 1) is obtained.

[effect]
The coil 1 having the above configuration is adjacent to each other because the cross-sectional shape of the straight portion 11 and the cross-sectional shape of the curved portion 12 are substantially equal and rectangular when taking a cross section of the winding 1w. The insulation distance between the turns can be made uniform over the entire coil 1. Further, in the conventional coil in which the inner peripheral side of the bending portion swells, since the insulation distance is designed by the distance between the inner peripheral side portions of the bending portion in adjacent turns, the axial length of the coil is long. On the other hand, since the insulation distance can be set according to the distance between the linear portions of adjacent turns, the coil 1 is shorter in the axial direction than the conventional coil and is small.

  In addition, by appropriately changing the arrangement state of the two cylindrical rollers 51a and 51b of the swinging roller portion 51, the coil 1 having a uniform thickness over the whole can be easily manufactured. Furthermore, by using the swing roller unit 51, it is possible to cope with windings of various sizes, and compared to the case of using a truncated cone roller, work such as roller replacement is unnecessary. Yes, excellent coil productivity. In particular, in the first embodiment, the coil 1 can also be formed continuously from the winding material 10w to the formation of the winding 1w (covered rectangular wire), so that the coil manufacturing time can be shortened. From the point of view, the coil productivity is excellent.

(Embodiment 2)
Hereinafter, the reactor of the present invention including the coil of the present invention will be described with reference to FIG. The reactor 2L includes a coil 2 having a pair of coil elements 2a and 2b, and an annular magnetic core 4 having a coil winding portion (not shown) through which the coil elements 2a and 2b are respectively inserted. Such a reactor 2L is used, for example, as a component of an in-vehicle converter. This reactor 2L is characterized by the shape of the coil 2. Specifically, each of the coil elements 2a and 2b has a rectangular frame-like end surface shape with rounded corners as in the coil 1 of the first embodiment, and the cross-sectional shape of the straight portion 21 and the curved portion 22 The cross-sectional shapes are equal and rectangular. Hereinafter, each configuration will be described in detail.

[Coil 2]
The coil 2 has a pair of coil elements 2a and 2b formed by spirally winding one continuous winding 2w. Each coil element 2a, 2b has a plurality of turns, and each turn has a straight portion 21 in which the winding 2w is arranged in a straight line, and the winding 2w is connected to the straight portion 21 and is curved. A curved portion 22. The two coil elements 2a and 2b are formed side by side so that their axial directions are parallel to each other.

  The winding 2w is a covered rectangular wire similar to the winding 1w of the first embodiment having a rectangular conductor cross section. Both the coil elements 2a and 2b are edgewise coils formed by edgewise winding the covered rectangular wire, and are connected by a winding portion 2r formed by folding a part of the winding 2w.

  Both end portions of the winding 2w forming the coil 2 are appropriately extended from the turn forming portion of the coil 2 as shown in FIG. 4 (I), and the conductor portion exposed by peeling off the insulating layer, A terminal member (not shown) made of a conductive material is connected. In addition to welding such as TIG welding, crimping or the like can be used to connect the winding and the terminal member.

  The coil 2 is manufactured in the same manner as the coil 1 of the first embodiment. That is, the coated round wire is used as a winding material, and this winding material is transformed into the winding 2w by the roller die portion, and then the swing roller portion is inserted. As in the first embodiment, the oscillating roller portion is arranged in a parallel state with respect to the portion where the linear portion 21 is formed and in an inclined state with respect to the portion where the curved portion 22 is formed. Then, the coil 2 is formed by feeding the winding 2w having a predetermined shape that has passed through the swing roller portion to the winding portion and winding it in a spiral manner as described above. A known method can be used to form the winding portion 2r.

[Magnetic core]
The magnetic core 4 will be described with reference to FIG. The magnetic core 4 has a pair of rectangular parallelepiped coil winding portions 4c where the coil 2 is disposed, and a pair of end cores 4e which are exposed without the coil 2 being disposed. A pair of end cores 4e are spaced apart so as to sandwich the coil winding portions 4c that are spaced apart in parallel, and are formed in a closed loop shape (annular shape). The coil winding portion 4c is configured by alternately laminating core pieces 4m made of a soft magnetic material containing iron such as iron or steel and gap members 4g made of a nonmagnetic material such as alumina. 4e is a core piece made of the soft magnetic material. Each core piece can be a soft magnetic powder compact or a laminate of a plurality of electromagnetic steel plates. The gap material 4g is a plate-like material disposed in a gap provided between the core pieces 4m for adjusting the inductance (there may be an air gap). The core piece and the gap material are integrally joined with an adhesive or the like. The number of core pieces and gap members can be appropriately selected so that the reactor 2L has a desired inductance. Moreover, the shape of a core piece or a gap material can be selected suitably.

[Other configurations]
(Insulator)
If the insulator 5 made of an insulating material is provided between the coil 2 and the magnetic core 4, the insulation between the coil 2 and the magnetic core 4 can be enhanced. Examples of the insulator 5 include a cylindrical bobbin (not shown) that covers the outer periphery of the coil winding portion and a pair of flange portions 5f (FIG. 4) that come into contact with the end surface of the coil 2. If the cylindrical bobbin is configured to engage half-cut square tube pieces, the outer periphery of the coil winding portion 4c can be easily covered. Each flange 5f is a rectangular frame disposed on one end side of the cylindrical bobbin. As the insulating material, an insulating resin such as polyphenylene sulfide (PPS) resin, liquid crystal polymer (LCP), or polytetrafluoroethylene (PTFE) resin can be used.

(Case)
The combination of the coil 2 and the magnetic core 4 may be used as it is (as shown in FIG. 4 (I)), but is housed in a metal case (not shown) such as aluminum, and further inside the case. A structure filled with an insulating resin (potting resin) (not shown) can be employed.

(Outside resin part)
Alternatively, the assembly may be configured not to be housed in a case but to be covered with an insulating resin and to include an outer resin portion 6 as shown in FIG. 4 (II). The outer resin portion 6 can be formed by cast molding, transfer molding, injection molding or the like of an insulating resin. By omitting the case, the reactor can be made smaller. Further, when a part of the magnetic core 4 and part of the coil 2 are exposed from the outer resin portion 6, heat of the magnetic core 4 and the coil 2 can be easily released and heat dissipation can be improved. Furthermore, when the case is omitted and the outer resin portion 6 is provided, the end of the winding 2w can be easily pulled out to an arbitrary location, and the degree of freedom in designing the location where the terminal member is connected can be increased. it can.

  Both end portions of the winding 2w are exposed from the potting resin or the outer resin portion 6 so that the terminal member can be attached. By storing in the case or having the outer resin part 6, the coil 2 and magnetic core 4 can be protected from the external environment such as dust and corrosion, mechanically protected, and the combined body It can be handled. As the insulating resin, epoxy resin, urethane resin, PPS resin, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin, unsaturated polyester (BMC) and the like can be used. When the resin is mixed with a filler made of at least one ceramic selected from silicon nitride, alumina, aluminum nitride, boron nitride, and silicon carbide, the insulating property is excellent and the heat dissipation is further improved.

[Assembly of the reactor]
The reactor 2L having the above configuration can be formed as follows.

  First, the coil 2 is formed based on the manufacturing method described in the first embodiment, and the coil 2 is prepared. In addition, the coil piece 4c is formed by fixing the core piece 4m and the gap material 4g with an adhesive or the like, and the cylindrical bobbin of the insulator 5 is disposed on the outer periphery thereof. Then, the coil elements 2a and 2b of the coil 2 thus prepared are respectively disposed in the coil winding portion 4c where the cylindrical bobbin is disposed, and the flange portion 5f and the end core 4e of the insulator 5 so as to sandwich the coil 2 therebetween. Are arranged on both end faces of the coil elements 2a and 2b, and the end core 4e and the coil winding part 4c are joined with an adhesive or the like. Through this process, a reactor 2L (FIG. 4 (I)) including the coil 2 and the magnetic core 4 is obtained. The obtained assembly comprising the coil 2 and the annular magnetic core 4 may be housed in a case and filled with potting resin, or coated with the outer resin portion 6 (FIG. 4 (II)). . Then, by attaching a terminal member to each end of the winding 2w, power can be supplied to the coil 2 via the terminal member.

[effect]
In the coil 2, each coil element 2a, 2b is similar to the coil 1 of the first embodiment, and the cross-sectional shape of the straight portion 21 and the cross-sectional shape of the curved portion 22 are substantially equal (rectangular shape), and adjacent turns The insulation distance between them is uniform over the entire coil 2. For this reason, the coil 2 is also smaller in size in the axial direction than the conventional coil, similarly to the coil 1 of the first embodiment. The reactor 2L including such a coil 2 is small in size because the length of the coil winding portion 4c of the magnetic core 4 (the size in the axial direction of the coil element 2a (2b)) can be shortened. Therefore, it is expected that the reactor 2L can be suitably used for a vehicle-mounted component that is desired to be small.

  In addition, in the reactor 2L, the end core 4e has a shape protruding from the coil winding portion 4c. Therefore, when the volume of the end core is constant compared to the magnetic core in which the outer peripheral surface of the coil winding portion and the outer peripheral surface of the end core are flush, the end core 4e has a length (coil axis). Since the size of the direction) can be shortened, it is small. This also applies to the reactor 3L of the third embodiment described later.

  In addition, in coil 2, although the form connected by rewinding part 2r was explained, by preparing a pair of coils 1 of embodiment 1, joining one end parts of the windings of two coils by welding or the like, A coil including a pair of coil elements can be provided. This also applies to the reactor 3L of the third embodiment described later.

(Embodiment 3)
Hereinafter, the reactor of the present invention including the coil molded body of the present invention will be described with reference to FIGS. The reactor 3L includes a coil molded body 3 having a coil 2 and an annular magnetic core 4 on which the coil molded body 3 is disposed. The main difference between the reactor 3L and the reactor 2L of the second embodiment is that the coil 2 is a coil molded body 3 covered with an inner resin portion 3c. Hereinafter, this difference will be mainly described, and the other points are substantially the same as the reactor 2L of the second embodiment, and thus the description thereof will be omitted.

[Coil molding]
The coil molded body 3 includes an inner resin portion 3c that covers the outer periphery of the coil 2, as shown in FIG. 6 (II). Here, the inner resin part 3c holds the coil elements 2a and 2b constituting the coil 2 in a predetermined shape. Further, as shown in FIG. 6, the inner resin portion 3c covers substantially along the outer shape of the coil 2, and both end portions of the winding 2w and part of the outer peripheral surface of the turn forming portion of the coil elements 2a and 2b are formed. The inner resin portion 3c is exposed without being covered with the constituent resin. In the inner resin portion 3c, the thickness of the portion covering the turn forming portions of the coil elements 2a and 2b is substantially uniform, and the portion covering the winding-back portion 2r has a shape protruding in the axial direction of the coil.

  The inner periphery of each coil element 2a, 2b is also covered with the constituent resin of the inner resin portion 3c, and has a hollow hole 3h formed by this constituent resin. A coil winding portion 4c (FIG. 7) of the magnetic core 4 (FIG. 7) is inserted and disposed in each hollow hole 3h. The thickness of the constituent resin of the inner resin portion 3c is adjusted so that each coil winding portion 4c is disposed at an appropriate position on the inner circumference of the coil elements 2a and 2b, and the shape of the hollow hole 3h is coiled. It matches the outer shape of the turning portion 4c (here, a rectangular parallelepiped shape). Therefore, the constituent resin of the inner resin portion 3c existing on the inner circumference of each of the coil elements 2a and 2b functions as a positioning portion for the coil winding portion 4c.

  When the reactor 3L with the coil molded body 3 is used as the constituent resin of the inner resin part 3c, it has heat resistance that does not soften against the maximum temperature of the coil 2 and magnetic core 4, and transfer molding A material that can be used for injection molding can be preferably used. In particular, a material having excellent insulating properties is preferable. Specifically, a thermosetting resin such as epoxy, or a thermoplastic resin such as PPS resin or LCP can be suitably used. Here, an epoxy resin is used. In addition, when the above-mentioned resin is mixed with the above-mentioned filler made of ceramics, the insulating property is excellent and the heat dissipation is further improved.

  The coil molded body 3 can be manufactured using a molding die as described below. As the molding die, one constituted by a pair of first and second molds that can be opened and closed can be used. The first mold is inserted into the end plate located on one end side of the coil 2 (the side from which the end of the winding 2w is pulled out in FIG. 6 (II)) and the inner circumference of each coil element 2a, 2b. The second mold has an end plate located on the other end side of the coil (on the side of the rewinding portion 2r in FIG. 6 (II)), and a peripheral side wall that covers the periphery of the coil 2. With The first mold and the second mold include a plurality of rod-like bodies that can be moved back and forth inside the mold by a driving mechanism, and these rod-like bodies appropriately press the end faces of the rectangular frames of the coil elements 2a and 2b. Then, the coil elements 2a and 2b are compressed. The rod-like body has sufficient strength against compression of the coil 2 and heat resistance against heat during molding of the inner resin portion 3c, and reduces the number of portions of the coil 2 that are not covered with the inner resin portion 3c. Furthermore, it is preferable to make it as thin as possible.

  The coil 2 is formed as described in the first and second embodiments, and the coil 2 is accommodated in the molding die so that a certain gap is formed between the surface of the molding die and the coil 2. . At this time, the coil 2 is not yet compressed.

  Next, the molding die is closed, and the cores of the first die are inserted into the inner circumferences of the coil elements 2a and 2b, respectively. At this time, the interval between the core and the inner periphery of the coil elements 2a and 2b is made substantially uniform over the entire periphery of the core.

  Subsequently, the rod-shaped body is advanced into the molding die to compress the coil elements 2a and 2b. By this compression, the gap between adjacent turns constituting each coil element 2a, 2b is narrowed, and the coil 2 is held in a state compressed more than its free length.

  While maintaining the compression state, the resin is filled into the molding die from the resin injection port. At this time, since the coil 2 is provided with uniform intervals between adjacent turns over the entire coil 2 as described above, the resin is uniformly filled between the turns. In addition, since the coil 2 is formed of a covered rectangular wire, a predetermined insulating characteristic can be ensured even if the resin is not filled between turns. By filling the entire resin between adjacent turns and interposing the resin between the turns, the insulation between the turns can be further enhanced. After the filled resin is cured, the molding die is opened, and the coil molded body held in the compressed state by the resin is taken out. Note that the plurality of small holes formed at the place pressed by the rod-shaped body may be left as they are, or may be filled with an appropriate insulating material or the like. Moreover, when it is not necessary to compress, the press by a rod-shaped body is unnecessary.

[Outside resin part]
The reactor 3L further includes an outer resin portion 6 that covers the outer periphery of the combined body 30 formed by combining the coil molded body 3 and the magnetic core 4. The outer resin part 6 is formed substantially along the outer shape of the combined body 30, and the end of the winding 2w exposed from the inner resin part 3c of the coil molded body 3 is exposed in the same manner as the reactor 2L of the second embodiment. I am letting. The surface of the inner resin portion 3c and the turn forming portion exposed from the inner resin portion 3c described above are in contact with the inner surface of the outer resin portion 6.

  As the constituent resin of the outer resin portion 6, the same resin as the outer resin portion 6 of the reactor 2L of the second embodiment described above can be used, which may be the same as or different from the constituent resin of the inner resin portion 3c of the coil molded body 3. Good.

[Reactor assembly procedure]
The reactor 3L having the above configuration can be assembled as follows.

  First, the coil molded body 3 is formed as described above. Further, as shown in FIG. 7, the coil piece 4c is formed by fixing the core piece 4m and the gap material 4g with an adhesive or the like. Then, the coil winding portion 4c is inserted and disposed in the hollow hole 3h of the coil molded body 3. Each coil winding portion 4c inserted into the hollow hole 3h is disposed at an appropriate position with respect to the coil elements 2a and 2b (FIG. 6). Next, the end core 4e is arranged so that both end faces of the coil molded body 3 are sandwiched between the pair of end cores 4e, and the end core 4e and the coil winding portion 4c are joined with an adhesive or the like. The union 30 is obtained. In the obtained combined body 30, the outer periphery of the combined body 30 is covered with resin so that the end of the winding 2w is exposed to form the outer resin portion 6, whereby the reactor 3L is obtained.

[effect]
The coil molded body 3 is small in size by including the coil 2 of the second embodiment, and the reactor 3L including such a coil molded body 3 is also small as in the reactor 2L of the second embodiment. In particular, the reactor 3L does not include a case, and is small and lightweight, but includes the inner resin part 3c and the outer resin part 6, thereby protecting the coil 2 and the magnetic core 4 from the external environment and machinery. Protection can be achieved. In addition, the reactor 3L is excellent in manufacturability because it uses the coil molded body 3 and the coil 2 does not expand and contract during assembly and is easy to handle. In addition, since the insulator can be omitted by using the coil molded body 3, it is possible to reduce the number of parts and the process of arranging these parts, and from this point, the productivity of the reactor is excellent. .

  In addition, in the reactor 3L, when the reactor is installed in the end core 4e or the coil molded body 3, the surface on the installation side is exposed from the outer resin portion 6, and the reactor is installed on these installation-side surfaces Since it can contact the cooling base, it has excellent heat dissipation. In the reactor 3L, since the outer peripheral surface of the coil molded body 3 has an uneven shape, the contact area between the coil molded body 3 and the outer resin portion 6 is increased, and the adhesion between the two is enhanced.

(Modification 1)
In the first to third embodiments described above, the configuration in which the coated round wire is processed into a coated rectangular wire and subsequently wound spirally has been described. In addition, a coated rectangular wire is prepared separately, and the coated rectangular wire is inserted into the swing roller portion in an appropriate arrangement state as described above, and subsequently wound spirally, and the straight portion and the curved portion A coil comprising

(Modification 2)
In the first to third embodiments, the configuration using the covered round wire has been described. In addition, a bare round wire that does not have an insulating coating can also be used. In this case, a bare round wire is inserted into the roller die portion to perform a drawing process to form a flat wire, and the flat wire is inserted into the swing roller portion appropriately arranged as described above, and subsequently spiraled. It is also possible to form a bare wire coil (edgewise coil) having a straight portion and a curved portion. Alternatively, a bare flat wire may be prepared in the same manner as in the second modification, and the bare wire coil may be formed as described above. In the obtained bare wire coil, insulation between adjacent turns can be ensured by interposing an insulating material such as insulating resin or insulating paper in the gap between adjacent turns. The interval between adjacent turns, the type of insulating material, and the like can be appropriately selected so as to ensure desired insulating characteristics.

  By using the swing roller portion as described above, a bare wire coil having a uniform thickness and an interval between adjacent turns can be obtained over the entire coil. Therefore, the insulating material interposed in the gap between adjacent turns also has a uniform thickness, and a predetermined insulating characteristic can be ensured over the entire coil.

  For example, when the bare wire coil is used in the reactor according to the second embodiment, a combination of the bare wire coil and the magnetic core is prepared, and the gap between adjacent turns is filled with the potting resin. It is good to fill with resin. Alternatively, when the outer resin portion is molded on the outer periphery of the assembly, the gap between adjacent turns may be filled with the constituent resin of the outer resin portion. When the bare wire coil is used, for example, in the coil molded body of the third embodiment, the inner resin portion may be filled with the constituent resin of the inner resin portion when the inner resin portion is molded.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration.

  The coil of the present invention and the coil molded body of the present invention can be suitably used as a component of a coil component such as a reactor. The reactor of the present invention including the coil and the coil molded body can be suitably used for a component part of a power conversion device such as a converter mounted on a moving body such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle. . The manufacturing method of the coil of the present invention can be suitably used for manufacturing the coil of the present invention.

1,2 Coil 1w, 2w Winding 2a, 2b Coil element 2r Winding part
3 Coil molded body 3c Inner resin part 3h Hollow hole
2L, 3L reactor
4 Magnetic core 4c Coil winding part 4e End core 4m Core piece
4g Gap material 5 Insulator 5f Ridge part 6 Outer resin part
10 Coil intermediate 10w Winding material 11,21 Straight part 11s Short side
11l Long side part 12,22 Curved part 30 Combined body
50 Coil manufacturing equipment 51 Oscillating roller 51a, 51b Cylindrical roller
52 Roller dies 52a, 52b Longitudinal roller dies
52c, 52d Horizontal roller die 53 Supply 54 Winding part 54a Round bar core part
54b Bend
100 square R coil 100w winding 110 straight part 120 curved part

Claims (2)

A winding having a rectangular conductor cross section is spirally wound, and a straight portion in which the winding is arranged in a straight line, and a curved portion in which the winding is curved and connected to the straight portion. A method of manufacturing a reactor coil comprising:
A step of drawing a round wire having a circular cross section to form a wire having a rectangular cross section of the conductor;
A pair of cylindrical rollers are arranged so that the axial directions of the respective rollers are parallel to each other, and the conductor cross section is inserted between both the cylindrical rollers, and the cross-sectional shape coming out between the cylindrical rollers is A wire that is not substantially changed is a winding, and the winding is conveyed linearly to form the linear portion;
The two cylindrical rollers are arranged so that the interval between the cylindrical rollers becomes wider from one end side to the other end side of both cylindrical rollers, and in this state, the conductor cross section is rectangular between the cylindrical rollers. A wire having a trapezoidal cross section that is inserted from the cylindrical roller and is thickened from one end side toward the other end side is used as a winding, and the thickness is thin in this winding. And a step of forming the bending portion by bending the winding so that the side is the inner peripheral side of the bending. A reactor comprising a coil and a magnetic core,
The coil includes a plurality of turns formed by spirally edgewise winding a winding having a conductor having a rectangular cross section and an insulating layer covering the outer periphery of the conductor;
Each of the turns includes a linear portion in which the winding is linearly arranged, and a curved portion in which the winding is connected to the linear portion and is curved,
The difference between the maximum value and the minimum value of the thickness of the linear portion constituting each turn is 0.3 mm or less,
The difference between the cross-sectional area of the straight part and the cross-sectional area of the curved part with respect to the cross-sectional area of the straight part when the cross-section of the winding is taken in the straight part and the curved part constituting each turn. The reactor whose ratio is 3% or less.

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