JP2001068364A - Toroidal coil and manufacturing method thereof. - Google Patents

Abstract

[PROBLEMS] To provide a method for easily manufacturing a small toroidal core having a large inductance value and a large current capacity and excellent in magnetic properties. SOLUTION: Each of the divided ring cores is inserted into a cylindrical coil core formed by winding a conductive wire in advance while bending a cylindrical coil into a ring shape, and a divided surface is formed. Join to form a ring core to complete the toroidal coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a toroidal coil used for reducing noise in a power supply circuit of an electronic device.

[0002]

2. Description of the Related Art As a surface mount inductance component for a demand for downsizing and low profile of electronic equipment, for a signal having a small current capacity, for example, a printed multilayer in which ferrite and an electrode pattern are alternately printed and integrally fired. There are two types: a multilayer type and an electrode pattern printed on a ferrite green sheet, which is laminated and fired integrally. However, those with a large current capacity are not available on the market because of their large size.

A coil having a large current capacity of several amperes or more and a large inductance value for a power supply circuit,
When a toroidal coil in which a copper wire is wound is used as a ring core and a magnetic saturation occurs due to DC superposition, a core having a slit in the ring core as shown in FIG. 1 has been used. In addition, when a small ring core is used, the inner diameter of the core becomes smaller, so that a winding machine cannot be used. In order to wind the coil, it is necessary to manually wind one turn at a time while passing a conductor through the inner diameter of the ring core. I was

[0004] In addition, a conventional toroidal coil is often used in which a copper round wire is wound around a ring core of ferrite or a magnetic alloy. However, in order to increase the inductance value, a large number of turns is required. Since the current capacity is reduced by winding the thin wire, there is a limit in reducing the size of a toroidal coil having a large inductance value and a large current capacity. In addition, it is difficult to wind a thick wire or a small ring core because the hardness of the wire increases.

[0005] The noise reduction inductor of the power supply circuit includes:
It is required that the inductance value is large and that magnetic saturation does not occur even when DC current is superimposed.Therefore, the magnetic properties of ferrite and magnetic steel plates that have been conventionally used are easily magnetically saturated, and the cross-sectional area must be reduced to meet the specifications. It had to be a large and large ring core.

[0006]

When a small toroidal core is manufactured, a ring core having a small inner diameter is used, so that a winding machine is not used, and a manual operation of winding one turn at a time while passing a conductor through the inner diameter of the ring core is required. However, the present invention has been to provide a manufacturing method which eliminates such complicated work.

In the conventional toroidal coil, a copper core wire wound around a ring core has been frequently used. However, a thin wire is advantageous for winding a large inductance value, that is, for winding a large number of turns. To increase the current capacity, a thick wire is advantageous and the two are contradictory, so there was a limit to the size reduction of a coil with a large number of windings and a large current capacity. The object is to provide a large and small toroidal coil.

[0008] The noise reduction inductor of the power supply circuit includes:
It is required that the inductance value is large and that magnetic saturation does not occur even when DC current is superimposed.For this reason, the magnetic properties of ferrite and magnetic alloys conventionally used had to be changed to a large ring core to meet the specifications. However, it is an object of the present invention to provide a small toroidal body using a small ring core by changing the material of the magnetic material.

[0009]

Means for Solving the Problems A first invention of the present invention is:
In the method for manufacturing a toroidal coil obtained by winding a conductor on a ring core, each of the ring cores previously divided is inserted into the air core portion of one or more cylindrical coils obtained by winding the conductor in advance, and inside the coil, The toroidal coil is completed by joining the divided surfaces to form a ring core.

According to a second aspect of the present invention, there is provided a method of manufacturing a toroidal coil in which a conductive wire is wound around a ring core, wherein the cylindrical coil formed by winding the conductive wire in advance has one surface to be an inner peripheral surface of the toroidal coil. After solidifying the gap between the wires with a flexible adhesive over the entire length of the coil, each of the ring cores previously divided is bent while bending the coil so that one surface of the coil becomes the inner peripheral surface of the ring. The toroidal coil is completed by being inserted into the coil air core, joining the divided surfaces and forming a ring core.

According to a third aspect of the present invention, there is provided a method for manufacturing a toroidal coil in which a conductive wire is wound around a ring core, wherein the tubular coil is previously divided into a tubular coil formed by winding a single rectangular wire or a multilayer double wire. Each of the ring cores is inserted into an air core portion of the coil, and the divided surfaces are joined to form a ring core. In the case of winding a rectangular tubular coil, when a thin and soft flat rectangular wire is wound on top of a predetermined thickness, it is easier to bend than a single wire having the same thickness, and the corner portion can be wound with a small radius of curvature.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a toroidal coil in which a conductive wire is wound around a ring core, wherein a ring core formed by winding or laminating a thin plate of an amorphous nanocrystalline alloy of 20 μm or less is divided. In addition, each of the divided ring cores is inserted into an air core portion of a previously wound tubular coil, and the divided surfaces are joined to form a ring core.

More specifically, the present invention for solving the above-mentioned problem is, as in the conventional method for manufacturing a toroidal coil,
Ring core with circular cross section using ferrite for magnetic material,
Instead of manufacturing a toroidal coil by winding a conductor on a ring core having a rectangular cross section obtained by winding or laminating a magnetic alloy thin plate, the conductor is wound by using a rod-shaped winding core having a cross section one size larger than the cross section of the ring core. A tubular coil is prepared in advance. Usually, a copper round wire coated with an insulating film is used.

Further, the ring core is cut to at least two pieces.
The core may be divided or the ring core may be manufactured in advance. Next, each of the divided cores is inserted into the air core from the coil end while bending the cylindrical coil into a ring shape, and the divided surfaces of the ring core are joined with water glass or epoxy resin inside the coil. A toroidal coil is completed by forming a ring core. At this time, it is preferable to make the bonding surface smooth and reduce the gap in order to increase the effective magnetic permeability. In the case of magnetic saturation due to DC superposition, slits of a predetermined interval are provided in the core as shown in FIG. 1. Can be shared. When a link core is formed inside two coils, a common mode coil and a transformer as shown in FIG. 3 are formed.

At this time, if the cross-sectional area of the conductive wire is large to some extent and the hardness is high, it is easy to insert the divided core while bending the cylindrical coil into a ring shape.
When the conductive wire is thin and soft, when the coil is bent, the space between the wires on the outer peripheral side is widened, the core is easily deformed, and the core is easily deformed. On the other hand, after the line between the surfaces that become the inner peripheral surface of the toroidal coil is hardened with a flexible adhesive after curing over the entire length of the coil, one surface of the coil becomes the inner peripheral side of the ring. Inserting the divided ring core while bending the coil allows easy insertion. Further, when the line of the coil on the inner peripheral surface of the toroidal coil is separated, when winding the coil around the core,
The wire is wound with the same spacing between the wires, and the space between the wires on the inner surface of the toroidal coil is fixed to a flexible tape or the like over the entire length of the coil. Further, it is more preferable to insert the split core while holding the tubular coil in a bent state with a jig using an outer frame.

Further, instead of a round wire as a wire material for the winding,
By winding up a rectangular wire with a rectangular cross section in order to narrow the winding width and increase the cross-sectional area, the number of turns can be increased and the current capacity can be increased. It is preferable that a rectangular wire with a large ratio of length and width be set up and rolled up. However, if the length is too long, the flat wire easily falls down and becomes hard and difficult to wind up.
The horizontal ratio is determined in consideration of winding workability. When a ring core having a rectangular cross section is used, the coil is wound into a rectangular cylindrical coil adapted to the cross section of the core. Since the portion is close to a right angle, that is, it can be wound with a small radius of curvature, a rectangular tube coil having a large current capacity can be made compact.

Further, a ring core formed by winding or punching a thin strip of an amorphous nanocrystalline alloy made of Fe, Zr, Nb, B or the like into a magnetic material having a thickness of 20 μm or less into a predetermined shape and then laminating the same is used. By using this, a toroidal coil having a high saturation magnetic density and a low magnetic saturation can be formed as shown in FIG. It is difficult to manufacture a thin ribbon of an amorphous nanocrystalline alloy, but if it is not at least 20 μm or less, eddy current loss cannot be ignored and high-frequency characteristics deteriorate. In addition, when the target ring core is thick, it is preferable to form by winding a thin band, and when the target ring core is thin, it is preferable to form by punching out and stacking thin plates.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. Thickness; 14mm, width; 1
6 mm rectangular section core, width; 0, 5 mm, thickness;
0, 35 mm rectangular annealed copper wire is superposed three times in thickness;
After winding 17 mm with a thickness of 05 mm, the insulating film on the coil terminal portion was removed, soldering was performed, and a flexible adhesive was applied to the expected inner peripheral surface of the toroidal coil to fix the gap between the coil wires. As shown in FIG.

A thin plate of an amorphous nanocrystalline alloy having a thickness of 0 or 02 mm (Nanopalm, manufactured by Alps Electric Co., Ltd.) is wound up, and has an outer diameter of 20 mmΦ, an inner diameter of 8 mmΦ, and a thickness of 12 mm.
After a ring core having a thickness of 2 mm was formed, coated with an epoxy resin and insulated, then cut with a dicing saw and divided into two parts as shown in the plan view of FIG.

Next, as shown in FIG. 6, while bending the rectangular tubular coil into a ring shape, the split core is inserted into the air core from both ends of the coil, and epoxy resin is applied to the split surface inside the coil. , Joining and curing to complete a toroidal coil as shown in FIG.

[0021]

As described above, according to the method of the present invention, a small toroidal coil having a large inductance value, a large current capacity, and excellent magnetic properties can be obtained without winding one turn at a time while passing a conductor through the inner diameter of the ring core. , Easy to manufacture.

[Brief description of the drawings]

Fig. 1 Ring core with slit

FIG. 2 Toroidal coil

FIG. 3 is a common mode coil

FIG. 4 is a square tubular coil

FIG. 5: Split ring core

FIG. 6 is a view showing a state in which a divided ring core is inserted into a coil air core portion.

FIG. 7 is a characteristic diagram of an amorphous nanocrystalline alloy magnetic material (nanopalm).

[Explanation of symbols]

 1 Ring core 2 Slit 3 Flat copper wire 4 Divided ring core

Claims (4)

[Claims] In a method of manufacturing a toroidal coil comprising a magnetic material ring core and a conductive wire wound thereon, each of the divided ring cores is formed into a cylindrical shape by previously bending a cylindrical coil formed by winding a conductive wire into a ring shape. Insert into the coil air core,
A method of manufacturing a toroidal coil, comprising forming a ring core by joining divided surfaces. 2. The method for manufacturing a toroidal coil according to claim 1, wherein the cylindrical coil is formed by winding a conductive wire in advance.
After the space between the surfaces of the inner surface of the toroidal coil is fixed over the entire length of the coil with a flexible adhesive, the surface is used as the inner surface of the ring-shaped coil, and each of the divided ring cores is formed. A method for manufacturing a toroidal coil, comprising inserting a ring core into a coil core portion and joining the divided surfaces to form a ring core. 3. A method for manufacturing a toroidal coil according to claim 1, wherein a rectangular wire is used as the conducting wire. 4. A method for manufacturing a toroidal coil according to claim 1, wherein a ring core formed by winding or laminating a thin plate of an amorphous nanocrystalline alloy of 20 μ or less on a magnetic material is used. Characterized toroidal coil.