JP2006147821A - Air-core toroidal coil manufacturing method and toroidal coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a toroidal coil which is capable of forming the toroidal coil easily without using a dedicated winding machine. <P>SOLUTION: The method of forming the toroidal coil 24 comprises a first process of forming a cylindrical bobbin 10 using a flexible and non-magnetic material, a second process of enabling a rigid shaft 20 to penetrate through the bobbin 10, a third process of winding a winding 22 on the bobbin 10 which is fixed and held by the shaft 20, a fourth process of pulling out the shaft 20 from the bobbin 10 wound with the winding 22, and a fifth process of fitting a fitting unit 12 into a fitting receiver 14 located at the end of the bobbin 10 from which the shaft has been pulled out to turn the bobbin 10 in annular shape for the formation of the toroidal coil 24. As mentioned above, the shaft 20 is inserted into the bobbin 10, so that the winding 22 can be easily wound on the cylindrical bobbin 10 by a conventional winding machine. The bobbin 10 can be easily turned in annular shape when the shaft 20 is pulled out after the winding 22 is wound on the bobbin 10. After the bobbin 10 is turned in annular shape, the fitting unit 12 provided to the one end of the bobbin 10 is fitted into the fitting receiver 14 provided to the other end of the bobbin 10, whereby the toroidal coil 24 can be easily formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an air core toroidal coil manufacturing method and a toroidal coil used for a switching power supply that performs a switching operation at a high frequency.

As a power supply device that obtains a voltage different from the input voltage, there is a switching power supply in which the input power supply is intermittently controlled and voltage conversion is performed by a transformer. Conventionally, an EI-shaped core has been used for the transformer, but there is little leakage inductance, and the external power supply A switching power supply that requires a standard that hardly dissipates noise may use a toroidal core 1 in which a winding 2 is wound around a toroidal core 1 as shown in FIG.
JP-A-9-027425 Japanese Utility Model Publication No. 10-050534

  However, the winding work of the toroidal coil is more difficult to wind than the transformer of the EI shape core, and the work time is longer than that of the transformer of the EI shape core. Although it is made to wind, since it lacked versatility, it had the subject that it was not suitable for small-lot, multi-product production.

Accordingly, an object of the present invention is to provide a toroidal coil manufacturing method and a toroidal coil with improved workability.

  In order to solve such problems, the present invention includes a first process of forming a rod-shaped bobbin with a flexible and non-magnetic material, a second process of penetrating a bobbin having a rigid bobbin, a core, A third process of winding a winding on a bobbin fixed and held by a rod, a fourth process of removing the core rod from the bobbin wound with the winding, and connecting the both ends of the bobbin from which the core rod is removed to form an annular shape. An air core toroidal coil is manufactured by a fifth process. By adopting such a manufacturing method, it has been possible to form a winding easily and in a short time using a dedicated manufacturing machine or a device that previously required a long manufacturing time.

  The present invention is characterized by a bobbin fitting structure, and the first step is characterized in that a fitting portion and a fitting receiving portion are formed at one end of a rod-shaped bobbin. With this configuration, the annular shape can be easily held.

  The present invention is characterized by the cross-sectional shape of the bobbin, and the first step is characterized in that the cross-sectional shape of the rod-shaped bobbin is formed into an arbitrary shape including an ellipse or a rectangle. With this configuration, it is possible to easily realize a specially shaped core such as a cylindrical shape that has been difficult to configure in the past.

  The present invention is characterized in that a high thermal conductivity material is used for the bobbin, and the first process is characterized in that the rod-shaped bobbin is formed of a material having a higher thermal conductivity.

  Further, the present invention is characterized in that the bobbin can be embedded and wound, and the third process is characterized in that the winding is wound so as to bite into the outer periphery of the bobbin fixedly held by the core rod.

  Further, the present invention forms a coil itself composed of a bobbin formed in a donut shape by connecting both ends of a flexible and non-magnetic rod-shaped material, and a winding wound around the outer periphery of the bobbin. It is characterized by that.

  Further, the present invention is characterized by a heat dissipation structure, and is characterized by including a heat dissipation member disposed with a bobbin interposed therebetween. Thus, heat dissipation efficiency can be improved by forming the bobbin with a material having high thermal conductivity or sandwiching the bobbin with the heat dissipation member. Further, by winding the winding around the outer periphery of the bobbin, the coil can be prevented from coming into contact with the heat radiating member, and the insulation problem can be solved.

Further, the present invention is characterized in that the winding is formed of a twisted wire or a fused multi-core wire, and the third process is characterized in that a twisted wire or a fused multi-core wire is wound around a bobbin fixedly held by a core rod. . With this configuration, a transformer having a winding ratio of 1: 1 can be easily obtained by a single winding. In this case, if it winds with one line, it will become a choke coil. In addition, a toroidal transformer having an arbitrary winding ratio can be obtained by individually winding a plurality of turns.

  According to the present invention, a winding is wound around a bobbin made of a flexible material through which a rigid mandrel is passed, and when the winding is finished, the mandrel is pulled out, the bobbin is deformed into an annular shape, and the ends are joined. Since the work is sufficient, the winding work can be performed only by rotating the bobbin around the axis, and the winding work can be simplified and the deformation to the toroidal shape can be easily performed.

  In addition, it is easy to connect the end part by providing a fitting part at one end of the bobbin and forming a fitting receiving part that fits the fitting part at the other end, because the bobbin has flexibility. It can be formed in an annular shape.

  Moreover, it is easy to make the cross-sectional shape of the bobbin an arbitrary shape such as an ellipse or a rectangle, and since the degree of freedom of the shape is large, there is an effect that mounting efficiency is improved.

  Further, if a material having high thermal conductivity is used for the bobbin, the heat radiation efficiency can be improved.

  Further, by using a soft material for the bobbin, the winding can be wound so as to bite into the outer periphery of the bobbin. In this case, even if the structure is sandwiched between the heat sinks on the bobbin, the coil is not damaged.

  In addition, there is an effect that a transformer can be easily formed by using a twisted wire or a fused multi-core wire for the winding.

  In addition, since the bobbin is made of a soft material, it is strong against vibration. If the bobbin is formed of silicon rubber, it can be firmly fixed with improved fusion with silicon, and the entire power supply can be potted.

  FIG. 1 is a diagram showing a manufacturing process of a toroidal core to which the present invention is applied, and FIG. 1 (A) is a diagram showing a first process. For example, a flexible and non-magnetic physical material such as silicon rubber. A rod-shaped bobbin 10 is formed of a material having a natural property, a mushroom-shaped fitting portion 12 is provided at one end of the rod-shaped bobbin 10, and a fitting receiving portion 14 to be fitted to the fitting portion 12 is provided at the other end. Forming.

  FIG. 1B is a diagram showing the second stroke. When the winding is wound around the rod-shaped bobbin 10, the bobbin 10 is flexible and the workability of the winding is poor. Inserting 10 makes the entire bobbin rigid and facilitates the winding work. FIG. 1C is a diagram showing a third stroke, in which the winding 22 is formed by winding a wire around the bobbin 10 having rigidity. In this case, the winding 22 may be wound so as to bite into the bobbin 10 fixedly held by the core rod 20. When winding the winding 22, a twisted wire or a fused multi-core wire may be wound around the bobbin 10 fixedly held by the core rod 20, and when wound with one wire, a choke coil is formed, and the twisted wire or the fused wire is fused. When it is wound with a multi-core wire, it becomes a transformer with a winding ratio of 1: 1, but if a different winding ratio is required, a separate winding may be provided.

  FIG. 1D is a diagram showing the fourth stroke. When the winding is completed, the mandrel 20 is removed. FIG. 1 (E) is a diagram showing the fifth stroke. When the core rod 20 is removed, the material is flexible and can be easily formed into an annular shape. As a result, the toroidal coil 24 is formed.

  A through hole may be provided from the fitting portion 12 to the fitting receiving portion 14 so that the core rod 20 can be easily passed.

  FIG. 2 is a diagram showing another embodiment, and in FIG. 1A, only one mushroom-shaped fitting portion 12 is formed. However, if a plurality of fitting portions 12 are formed as shown in FIG. Even if a strong material is used, it is easy to secure a bonded state.

  The toroidal coil constructed in this way uses the bobbin 10, but since the bobbin 10 uses a non-magnetic material, the leakage flux is large and the coupling is not good compared to the one using a magnetic material. To cover these drawbacks. In addition, when the switching frequency of the switching power supply is set to several MHz or more, the use of a magnetic material increases the iron loss or decreases the magnetic permeability, so that the switching frequency of several MHz or more cannot actually be used. However, unlike the present invention, since no magnetic material is used, iron loss does not occur, and there is no problem of low magnetic permeability. Therefore, a switching power supply having a high frequency, which has been difficult to use in the past, is configured. It becomes easy.

  FIG. 3 is a diagram showing another embodiment. When a toroidal coil is manufactured, it is difficult to manufacture a cylindrical one, but since the shape of the bobbin 10 can be freely formed, the bobbin 10 having a flat cross section is used. For example, a cylindrical toroidal coil 24 can be easily formed as shown in FIG. In this way, it is possible to increase the mounting efficiency by reducing the area by using a cylindrical shape. FIG. 3B is a partial cross-sectional view of FIG. 3A, and in this example, it has an elliptical cross section, but may have a rectangular cross section or an arbitrary cross section.

  In this case, although not shown in the drawing, the fitting portion and the fitting receiving portion are formed at a plurality of locations at one end and the other end of the bobbin 10 to ensure fitting properties.

  Since the bobbin 10 has flexibility, it can be deformed into an arbitrary shape. For example, the bobbin 10 can be formed into a free shape as shown in FIG. The mounting efficiency is also improved. In this case, if the problem of heat dissipation seems to occur when enclosed in a sealed space, the bobbin 10 has a high thermal conductivity, and the bobbin 10 is brought into contact with a high heat dissipation effect such as a housing to reduce heat dissipation. Can solve the problem. Furthermore, if heat generation seems to be a problem, it is conceivable to use a heat-resistant or flame-retardant material or a material whose physical composition does not easily change due to heat.

  FIG. 5 is a view showing another embodiment, which is a toroidal coil in which the bobbin 10 is formed in an annular shape after the winding 22 is wound around the outer periphery of the rod-shaped bobbin 10 having high thermal conductivity. FIG. 6 shows the toroidal coil bobbin 10 configured as shown in FIG. 5 sandwiched between the heat radiating plate 26 and the substrate 28 to improve the heat radiating effect, and the winding 22 does not directly contact the heat radiating plate 26, thus ensuring insulation. It's easy to do. In this case, more heat dissipation can be expected if the copper foil is left in the portion where the substrate 28 is also in contact with the bobbin 10. In order to reduce loss due to eddy current, the substrate 28 preferably has a high electrical resistance, and a heat dissipation effect can be expected by using a substrate having a low thermal resistance.

Moreover, since the bobbin is made of a soft material, it is strong against vibration. Further, if the bobbin is formed of silicon rubber, the fusion with silicon can be improved and firmly fixed, and the entire power supply can be potted.

Diagram showing manufacturing process The figure which shows the other embodiment of a bobbin Illustration for forming a cylindrical bobbin Illustration for forming an arbitrarily shaped bobbin Diagram showing a toroidal coil wound around the bobbin's outer periphery. Diagram showing a state where a toroidal coil wound around the bobbin's outer periphery is sandwiched between a heat sink and a substrate A perspective view showing a conventional toroidal coil

Explanation of symbols

10: Bobbin 12: Fitting portion 14: Fitting receiving portion 16: Through hole 20: Core rod 22: Winding 24: Toroidal coil 26: Heat sink 28: Substrate

Claims (9)

A first step of forming a rod-shaped bobbin with a flexible and non-magnetic material;
A second process of penetrating the bobbin with a rigid core,
A third step of winding a winding around a bobbin fixedly held by the core rod;
A fourth step of removing the core rod from the bobbin wound with the winding;
A fifth step of connecting the both ends of the bobbin from which the core rod has been pulled out to form an annular shape;
An air core toroidal coil manufacturing method characterized by comprising:
2. The method of manufacturing an air core toroidal coil according to claim 1, wherein the first step includes forming a fitting portion and a fitting receiving portion at one end of the rod-shaped bobbin. Production method.
2. The method of manufacturing an air-core toroidal coil according to claim 1, wherein the first step forms the cross-sectional shape of the rod-shaped bobbin into an arbitrary shape including an ellipse or a rectangle. Manufacturing method.
2. The method of manufacturing an air-core toroidal coil according to claim 1, wherein the first step forms the rod-shaped bobbin with a material having a higher thermal conductivity.
2. The method of manufacturing an air core toroidal coil according to claim 1, wherein in the third step, the winding is wound so as to bite into an outer periphery of a bobbin fixedly held by the core rod. Coil manufacturing method.
2. The air core toroidal coil manufacturing method according to claim 1, wherein the third step comprises winding a twisted wire or a fused multi-core wire around a bobbin fixedly held by the core rod. Manufacturing method.
2. The method of manufacturing an air-core toroidal coil according to claim 1, wherein the third step includes winding a plurality of windings on a bobbin fixed and held by the core rod at the time of manufacturing a transformer and 1 at the time of manufacturing a choke coil. An air-core toroidal coil manufacturing method characterized by winding a winding of a book.
A bobbin formed into an annular shape by connecting both ends of a flexible and non-magnetic rod-shaped material;
A winding wound around the outer periphery of the bobbin;
A toroidal coil characterized by comprising:
  9. The toroidal coil according to claim 8, further comprising a heat radiating member disposed with the bobbin interposed therebetween.

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