JP2010287822A - Method for manufacturing reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a reactor for reducing the variations in the shape of a coil, and that facilitates stabilization of the inductance characteristics. <P>SOLUTION: A coil unit 4 is formed of a cylindrical bobbin 2, made of insulating materials and a coil 3 configured by winding a wire 30 around the bobbin 2. Then, the coil 3 is compressed in the axial direction, and the bobbin 2 is compressed, and a side face 21 of the bobbin 2 is bent so that the radius can be made a maximum at the central part of the axial direction, and the wire 30 is extruded from the inside of the coil 3 by the side face 21 so that the wire 30 of the coil 3 is aligned along the side face 21 of the bobbin 2 in an alignment process. As a result of this, variations in the inductance characteristics becomes less by fixing the shape of the coil 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reactor manufacturing method in which inductance characteristics are easily stabilized.

  Conventionally, as shown in FIG. 11, there is known a reactor 90 including a core 91 made of a magnetic powder mixed resin in which magnetic powder is dispersed in a resin, and a coil 92 embedded in the core 91 (the following patent document). 1). The coil 92 is formed by winding a conducting wire such as a rectangular wire, and an insulating film 93 for insulating from the magnetic powder is applied to the surface of the coil 92. Such a reactor 90 is used for an inverter of a vehicle, for example.

JP 2008-147345 A

However, the conventional reactor 90 has a problem in that the winding shape of the coil 92 varies as shown in FIG. 11, and the inductance characteristics are difficult to stabilize.
That is, if the shape of the coil 92 varies, the characteristics of the coil 92 itself are likely to vary, and it becomes difficult to house the coil 92 in the case 94 during manufacturing. Prone to instability. Also, the cross-sectional shape of the core 91 is difficult to stabilize. As a result, the inductance characteristics tend to vary.
Therefore, there is a demand for a reactor manufacturing method in which the variation in coil shape is small and the inductance characteristics are easy to stabilize.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method of manufacturing a reactor in which variations in coil shape are small and inductance characteristics are easy to stabilize.

The present invention is a method of manufacturing a reactor comprising a core made of a magnetic powder mixed resin in which magnetic powder is dispersed in a resin, and a coil embedded in the core,
A coil unit forming step of forming a coil unit including a cylindrical bobbin made of an insulating material and the coil formed by winding a conductive wire around the bobbin;
The coil is compressed in the axial direction, the bobbin is compressed, the side surface of the bobbin is curved so that the radius becomes maximum at the central portion in the axial direction, and the conductive wire is pushed out from the inside of the coil by the side surface. An alignment step of aligning the conductive wires of the coil along the side surface of the bobbin;
A core forming step in which the coil unit in which the coils are aligned is embedded in a mixture of the uncured resin and the magnetic powder, and the resin is cured to form the core;
The present invention resides in a method for manufacturing a reactor (claim 1).

The function and effect of the present invention will be described.
In the present invention, a coil unit including a cylindrical bobbin made of an insulating material and a coil formed by winding a conductive wire around the bobbin is formed. Then, by conducting the above alignment step, the conducting wire is pushed out from the inside of the coil, and this conducting wire is aligned along the side surface of the bobbin.
That is, when winding a conducting wire, the winding shape of the conducting wire is not always constant, and the coil shape obtained in the coil unit forming process varies. The conductive wires of the coil in which the shape variation has occurred are aligned in the alignment step.
Thereby, the variation in the shape of the coil is reduced, and the inductance characteristics can be stabilized. When the variation of the coil is small, the characteristics of the coil itself are stabilized, and it becomes easy to perform the operation of putting the coil into the storage case at the time of manufacture, and the position of the coil in the storage case and the cross-sectional shape of the core are easily stabilized. For this reason, the inductance characteristics are easily stabilized.
Further, since the coils are compressed in the axial direction in the alignment step, the height variation of the coils can be reduced. Furthermore, since the bobbin itself is made of an insulating material, the insulation on the inner surface of the coil can be enhanced.

  In the coil unit forming step, the coil unit may be formed by directly winding a conductive wire around the bobbin, or the bobbin may be assembled to a separately formed coil.

  As described above, according to the present invention, it is possible to provide a method for manufacturing a reactor in which variation in coil shape is small and inductance characteristics are easy to stabilize.

FIG. 3 is a partial perspective view of the reactor in the first embodiment. FIG. 3 is a perspective view of a bobbin in the first embodiment. Explanatory drawing of the coil unit formation process in Example 1. FIG. The figure following FIG. FIG. 3 is an explanatory diagram of an alignment process in the first embodiment. FIG. 3 is an explanatory diagram of an insulating film forming process in Example 1. The principal part enlarged view of FIG. Explanatory drawing of the core formation process in Example 1. FIG. Sectional drawing of the reactor in Example 1. FIG. The example which formed the insulating film inside the bobbin in Example 1. FIG. Sectional drawing of the reactor in a prior art example.

A preferred embodiment of the present invention described above will be described.
In the present invention, the bobbin has a flange, and in the state where the alignment process is completed, the flange protrudes radially outward from the outer surface of the portion adjacent to the flange in the coil, It is preferable to perform an insulating film forming step of forming an insulating film that covers the outer surface of the coil and adheres to the surface of the flange portion.
If it does in this way, it will become easy to improve the insulation performance of a coil. That is, when the bobbin is not used as in the prior art (see FIG. 11), the insulating film 93 is thin at the corner 92a of the coil 92, and the insulating performance may be lowered. However, in this example, since the insulating film formed on the outer surface of the coil is adhered to the surface of the collar portion of the bobbin, the thickness of the insulating film is difficult to be reduced at the corner of the coil. Thereby, the insulation performance of a coil can be improved.

The bobbin is divided into two in the axial direction, and in the coil unit forming step, the divided bobbins are respectively inserted from both ends of the coil, and the bobbin is integrated in a state of being assembled to the coil. (Claim 3).
In this case, since the bobbin is divided, the bobbin can be easily assembled to the coil formed in advance even if the bobbin has a flange. In addition, when a conducting wire is wound directly on a bobbin, the bobbin may bend due to the force when the conducting wire is wound, but if a coil is formed in advance as described above and the bobbin is assembled to the coil, this Such problems can be avoided.
Thereby, the bobbin which consists of soft materials like resin can be used. Therefore, it becomes easy to bend the side surface of the bobbin in the alignment step.

In the alignment step, it is preferable that the coil is compressed until the axial length of the coil reaches a predetermined value.
In this way, since the axial length of the coil can be made constant, the inductance characteristics are less likely to vary.

Example 1
The manufacturing method of the reactor 1 concerning the Example of this invention is demonstrated using FIGS. FIG. 1 is a partially transparent perspective view of a manufactured reactor 1, and FIG. 2 is a perspective view of a bobbin 2. In this example, the reactor 1 is formed by performing a coil unit formation step (FIGS. 3 and 4), an alignment step (FIG. 5), an insulating film formation step (FIGS. 6 and 7), and a core formation step (FIG. 8). Form.

As shown in FIG. 1, this example is a method of manufacturing a reactor 1 including a core 5 made of a magnetic powder mixed resin in which magnetic powder is dispersed in a resin, and a coil 3 embedded in the core 5.
In the manufacturing method of the reactor 1 of this example, as shown in FIGS. 3 and 4, a cylindrical bobbin 2 made of an insulating material (see FIG. 2), and a coil 3 formed by winding a conducting wire 30 around the bobbin 2, The coil unit formation process which forms the coil unit 4 which consists of is performed.
Thereafter, as shown in FIG. 5, the coil 3 is compressed in the axial direction, and the bobbin 2 is compressed, and the side surface 21 of the bobbin 2 is curved so that the radius becomes maximum at the central portion in the axial direction. An alignment step of aligning the conductive wire 30 of the coil 3 along the side surface 21 of the bobbin 2 by pushing the conductive wire 30 from the inside of the coil 3 is performed.
Next, as shown in FIG. 8, a coil forming process is performed in which the coil unit 4 in which the coils 3 are aligned is embedded in a mixture 50 of uncured resin and magnetic powder, and the resin is cured to form the core 5.
The details will be described below.

As shown in FIGS. 3 and 4, in this example, in the coil unit forming step, the conductive wire 30 is wound in advance to form the coil 3. Until the alignment process is performed, the shape variation of the coil 3 is large. The bobbin 2 is made of resin and has flanges 6 at both ends.
Further, as shown in the figure, the bobbin 2 is divided into two in the axial direction. In the coil unit forming step, the divided bobbins 2 are respectively inserted from both ends of the coil 3 and assembled to the coil 3. 2 is integrated.

Further, as shown in FIG. 5, in the alignment step, the bobbin 2 is pressurized in the axial direction, and the coil 3 is compressed using the flange portion 6. And the cylindrical part 20 is curved so that a radius may become the maximum in the axial center part. Thereby, the conducting wire 30 is pushed out from the inside and aligned.
In the alignment step, the coil 3 is compressed until the axial length of the coil 3 reaches a predetermined value.

Further, the bobbin 2 has a flange portion 6, and in a state where the alignment process shown in FIG. 5 has been completed, the flange portion 6 protrudes radially outward from the outer surface of the portion 33 of the coil 3 adjacent to the flange portion 6. Yes. Then, after performing the alignment process, as shown in FIGS. 6 and 7, an insulating film forming process is performed for forming the insulating film 8 that covers the outer surface 31 of the coil 3 and adheres to the surface 60 of the flange 6.
Thereafter, a curing step for curing the insulating film 8 is performed. When the insulating film 8 is cured, the coil 3 is adhered and fixed to the insulating film 8 in that state. Therefore, even if the compressive force of the bobbin 2 is released, the coil 3 can be kept in an aligned state and cannot be restored to the original state.

  Thereafter, as shown in FIG. 8, the coil unit 4 is housed in the case 7. Next, a mixture 50 in which magnetic powder is mixed with uncured thermosetting resin is placed in the case 7. Then, heat treatment is performed at a predetermined temperature to cure the thermosetting resin. Thereby, the core 5 is formed, and the reactor 1 is formed as shown in FIG.

  In the above embodiment, the insulating film 8 is formed only on the outer surface 31 of the coil 3. However, as shown in FIG. 10, the insulating film 8 is formed on both the inner surface 22 of the bobbin 2 and the outer surface 31 of the coil 3. It may be formed. In this way, the coil 3 can be firmly fixed by the two insulating films 8a and 8b, so that it is difficult for the coil 3 to be restored to the original state when the compressive force of the bobbin 2 is released. In order to form the reactor 1, for example, a method of dipping the coil unit 4 (see FIG. 5) in a container containing an insulating material after the alignment process is completed can be employed. Thereby, the insulating film 8 can be applied and formed on the outer surface 31 of the coil 3 and the inner surface 22 of the bobbin 2.

Next, the function and effect of this example will be described.
In this example, as shown in FIGS. 3 and 4, a coil unit 4 including a cylindrical bobbin 2 made of an insulating material and a coil 3 formed by winding a conducting wire 30 around the bobbin 2 is formed. Then, by conducting the alignment process shown in FIG. 5, the conducting wire 30 is pushed out from the inside of the coil 3, and the conducting wire 30 is aligned along the side surface 21 of the bobbin 2.
That is, when the conducting wire 30 is wound, the winding shape of the conducting wire 30 is not necessarily constant, and the shape of the coil 3 obtained in the coil unit forming process varies. The conducting wire 30 of the coil 3 in which the shape variation has occurred is aligned in the alignment step.
Thereby, the variation in the shape of the coil 3 is reduced, and the inductance characteristics can be stabilized. If the variation of the coil 3 is small, the characteristics of the coil 3 itself are stabilized, and it becomes easy to perform the operation of putting the coil 3 in the storage case 7 during manufacturing. The position of the coil 3 in the storage case 7 and the cross-sectional shape of the core 5 Also become more stable. For this reason, the inductance characteristics are easily stabilized.
Further, since the coil 3 is compressed in the axial direction in the alignment step, the height variation of the coil 3 can be reduced. Furthermore, since the bobbin 2 itself is made of an insulating material, the insulation on the inner surface of the coil 3 can be enhanced.

As shown in FIGS. 3 and 4, in this example, the bobbin 2 is divided into two in the axial direction. In the coil unit 4 forming step, the divided bobbins 2 are inserted from both ends of the coil 3, respectively. The bobbin 2 is integrated in the assembled state.
In this case, since the bobbin 2 is divided, the bobbin 2 can be easily assembled to the coil 3 formed in advance even if the bobbin 2 is provided with the flange portion 6. Further, when the conducting wire 30 is directly wound around the bobbin 2, the bobbin 2 may be bent by the force when the conducting wire 30 is wound. However, as described above, the coil 3 is formed in advance, and the bobbin 2 If 2 is assembled, such a problem can be avoided.
Thereby, the bobbin 2 which consists of soft materials like resin can be used. Therefore, it becomes easy to bend the side surface of the bobbin 2 in the alignment step (see FIG. 5).

In this example, in the alignment step shown in FIG. 5, the coil 3 is compressed until the axial length of the coil 3 reaches a predetermined value.
In this way, since the axial length of the coil 3 can be made constant, the inductance characteristics are less likely to vary.

Further, in this example, the bobbin 2 has the flange portion 6, and the flange portion 6 is radially outer than the outer surface of the portion 33 adjacent to the flange portion 6 of the coil 3 in the state where the alignment process shown in FIG. Protrudes up to. Then, after performing the alignment process, as shown in FIGS. 6 and 7, an insulating film forming process is performed for forming the insulating film 8 that covers the outer surface 31 of the coil 3 and adheres to the surface 60 of the flange 6.
This makes it easier to improve the insulation performance of the coil 3. That is, when the bobbin is not used as in the prior art (see FIG. 11), the insulating film 93 is thin at the corner 92a of the coil 92, and the insulating performance may be lowered. However, in this example, since the insulating film 8 formed on the outer surface 31 of the coil 3 is adhered to the surface 60 of the flange 6 of the bobbin 2, the thickness of the insulating film 8 is thin at the corner 32 of the coil 3. Hard to become. Thereby, the insulation performance of the coil 3 can be improved.

  As described above, according to this example, it is possible to provide a method for manufacturing the reactor 1 in which the variation in the shape of the coil 3 is small and the inductance characteristics are easy to stabilize.

1 Reactor 2 Bobbin 3 Coil 30 Conductor 4 Coil Unit 5 Core 6 Hut 8 Insulating Film

Claims (4)

A reactor manufacturing method comprising a core made of a magnetic powder mixed resin in which magnetic powder is dispersed in a resin, and a coil embedded in the core,
A coil unit forming step of forming a coil unit including a cylindrical bobbin made of an insulating material and the coil formed by winding a conductive wire around the bobbin;
The coil is compressed in the axial direction, the bobbin is compressed, the side surface of the bobbin is curved so that the radius becomes maximum at the central portion in the axial direction, and the conductive wire is pushed out from the inside of the coil by the side surface. An alignment step of aligning the conductive wires of the coil along the side surface of the bobbin;
A core forming step in which the coil unit in which the coils are aligned is embedded in a mixture of the uncured resin and the magnetic powder, and the resin is cured to form the core;
The manufacturing method of the reactor characterized by performing.   The bobbin according to claim 1, wherein the bobbin has a flange portion, and in the state where the alignment step is finished, the flange portion protrudes radially outward from an outer surface of a portion of the coil adjacent to the flange portion, A method of manufacturing a reactor, comprising: performing an insulating film forming step of forming an insulating film that covers an outer surface of the coil and adheres to the surface of the flange portion.   3. The state according to claim 1 or 2, wherein the bobbin is divided into two in the axial direction, and the divided bobbins are respectively inserted from both ends of the coil and assembled to the coil in the coil unit forming step. A method of manufacturing a reactor, wherein the bobbin is integrated.   4. The method of manufacturing a reactor according to claim 1, wherein, in the alignment step, the coil is compressed until an axial length of the coil becomes a predetermined value. 5.

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