JPH09320858A - Magnetic core with gap - Google Patents

Abstract

(57) Abstract: A magnetic core in which noise generated by an audible frequency is suppressed to a minimum. SOLUTION: A magnetic core made of an annular laminated body in which a magnetic ribbon is wound, and a gap formed by cutting the annular laminated body in a magnetic path of the magnetic core are provided, a spacer is inserted into a cut surface of the gap, and the spacer is cut. A magnetic core with a gap is created by closely adhering to the surface and adhering to the magnetic core with an adhesive, and the length of the spacer with respect to the stack height (thickness) of this annular stack is the stack height (thickness).
Or a magnetic core with a gap larger than the stack height (thickness).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magnetic core with a gap used in an electric circuit.

[0002]

2. Description of the Related Art Generally, a magnetic core is formed by winding a ribbon (amorphous magnetic ribbon) made of an amorphous metal (including an alloy),
It is made by stacking several annular pieces made by punching out amorphous magnetic ribbons.

Such a magnetic core is prepared by winding an amorphous magnetic ribbon, impregnating and covering it with a synthetic resin such as epoxy, and hardening it into a certain shape. When providing a gap in this magnetic core, the amorphous magnetic core is cut by a cutting machine to separate into two cut magnetic cores, or a part of the magnetic core is cut by a cutting machine.

Next, when the cut surfaces of the cut magnetic cores facing each other or a part of the magnetic cores are cut,
A spacer such as a polyester film or a gap paper is inserted between the cut surfaces so as to sandwich them.

Here, after the spacer is inserted into the gap, in order to prevent the spacer from coming off from the gap due to the vibration of the magnetic core, the spacer is brought into close contact with the cut surface and adhered to the magnetic core with an adhesive to form the magnetic core with the gap. create.

By insulating the magnetic core produced in this way and winding the winding of the conductor, a toroidal coil used in an electric circuit is completed. In this magnetic core with a gap, when the current flowing through the coil is AC,
The magnetic core vibrates according to the frequency of alternating current, and when the frequency is an audible frequency, there is a problem that sound waves are generated from the magnetic core and observed as annoying noise.

Conventionally, in a magnetic core with a gap, as shown in FIGS.
The spacer length TA of the annular laminated body is smaller than the laminated height (thickness) thereof is smaller than the laminated height (thickness) of the annular laminated body is adhered to the cut surface of the magnetic core with an adhesive to fix the amorphous magnetic ribbon. ing.

However, these conventional magnetic cores with a gap have a problem that the noise generated during their operation is still large.

[0009]

As a result of research, the present inventor has found that the vibration of the magnetic core can be effectively suppressed by changing the length of the spacer.

An object of the present invention is to provide a magnetic core in which noise generated by audible frequencies is suppressed to a minimum.

[0011]

[Means for Solving the Problems] A magnetic core is formed of an annular laminated body in which a magnetic ribbon is wound, and a gap formed by cutting the annular laminated body is provided in the magnetic path of this magnetic core.

Next, a spacer is inserted into the cut surface of the gap, and the spacer is brought into close contact with the cut surface and bonded to the magnetic core with an adhesive to obtain a magnetic core with a gap. Then, the length of the spacer with respect to the stacking height (thickness) of the annular stacked body that constitutes this gapped core is the same as the stacking height (thickness) or is larger than the stacking height (thickness). .

Next, the magnetic core has a cylindrical shape.
The magnetic core with the gap described is used. The magnetic core with a gap according to claim 1, wherein the spacer is a spacer in which glass fibers are laminated.

Next, the magnetic core with a gap according to claim 1, wherein the spacer is a spacer formed by laminating glass fibers, impregnating an epoxy resin and curing the epoxy resin. A magnetic core with a gap according to claim 1, wherein the magnetic ribbon is a magnetic ribbon made of an amorphous magnetic alloy.

The gapped magnetic core according to claim 1, wherein the length of the spacer is in the range of 1.0 to 2.0 times the stacking height (thickness) of the annular stack. Further, a magnetic core made of an annular laminated body in which a magnetic ribbon is wound is created, and a gap formed by cutting the annular laminated body is provided in the magnetic path of this magnetic core.

Next, a spacer is inserted into the cut surface of the gap, the spacer is brought into close contact with the cut surface, and a magnetic core with a gap is obtained by adhering it to the magnetic core with an adhesive. Further, as the spacer, a spacer having a gap equal to or higher than a stacking height (thickness) forming the magnetic core with a gap or a length larger than the stacking height (thickness) is used, did.

Next, the magnetic core with a gap according to claim 7, wherein the magnetic core is cylindrical and the spacer is a spacer in which glass fibers are laminated. As a result, the length of the spacer corresponding to the stacking height (thickness) of the annular stacked body is made equal to the stacking height (thickness) or larger than the stacking height (thickness). Since the ribbon is fixed to the spacer with an adhesive, the vibration of the magnetic core can be suppressed to a minimum.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment according to the present invention is shown in FIG.
The description will be made based on First, a magnetic core with a gap according to the present embodiment is a magnetic core obtained by impregnating a synthetic resin into an annular laminate (toroidal core) obtained by winding an amorphous magnetic ribbon.
1 is a component.

The magnetic core 1 made of a magnetic material is not limited to an annular laminated body (toroidal core) obtained by winding a magnetic material ribbon, but a plurality of ring-shaped magnetic material ribbons are laminated with an adhesive or the like. It includes a fixed laminated body or one obtained by compression-molding magnetic powder (compressed magnetic core). The form of the laminate is not particularly limited, and may be any form such as toroidal type, EI type and CI type.

Examples of the magnetic material used as the material of the magnetic core 1 include ferrite, permalloy, amorphous alloy, and microcrystalline alloy. As the amorphous alloy, for example, Fe-B-Si, Fe-BC, Fe-Co-
Fe-based amorphous alloy such as B-Si or Co-BS
Examples thereof include Co-based amorphous alloys such as i, Co-B, and Co-Fe-Ni-Si-B and Ni-based amorphous alloys. Examples of microcrystalline alloys include Fe-Si-B-Cu-Nb. Fe
Examples include microcrystalline alloys.

Examples of the synthetic resin to be impregnated include thermoplastic resins and thermosetting resins as shown in the following examples. That is, epoxy resin, acrylate resin, G
F (glass fiber) -containing phenol resin, polyimide resin, polyurethane resin, ethylene-vinyl acetate copolymer
Examples include PB (polybutene), PBT (polybutylene terephthalate), PMMA, polystyrene, GF-containing ABS, nylon 12, and GF-containing polycarbonate.

The temperature of the molten synthetic resin is 0 ° C. to + 300 ° C. higher than the softening temperature or the melting temperature, particularly +50.
A temperature as high as about + 100 ° C. is desirable. When the gap 2 is provided in the magnetic core 1, for example, the annular laminated body forming the magnetic core 1 is cut by a cutting machine to separate into two cut magnetic cores, or the annular core forming the magnetic core 1 is cut. It is performed by a method of cutting a part of the laminate with a cutting machine.

The magnetic core with a gap according to the present embodiment is obtained by cutting a part of the annular laminated body forming the magnetic core 1 with a cutting machine. Next, the spacer 3 to be inserted into the gap
As the material of, a laminated glass fiber, polyvinyl chloride, ceramics, etc. are used, but the magnetic core with a gap according to the present invention uses a laminated glass fiber from the viewpoint of practicality and noise reduction effect. There is.

Particularly preferred is a glass fiber laminated with an epoxy resin impregnated and cured. For example, the spacer 3 to be inserted into the gap is manufactured by laminating glass fibers, impregnating with epoxy resin, and then annealing and hardening at 380 ° C. for 2 hours in a nitrogen atmosphere.

When the cut surfaces of the cut magnetic cores facing each other or a part of the annular laminated body forming the magnetic core 1 is cut, the cut magnetic cores are sandwiched by the cut surfaces, and the spacer 3 is interposed therebetween. Insert.

Here, the magnetic core 1 according to the frequency of the alternating current
In order to prevent the spacer 3 from coming off from the gap 2 due to the vibration of, the spacer 3 is brought into close contact with the cut surface and bonded to the magnetic core 1 with an adhesive to form a magnetic core with a gap.

Examples of the adhesive used include Loctite 407, cyanoacrylate, epoxy resin, and silicone. Next, the length TA of the spacer with respect to the stacking height (thickness) of the annular stacked body is made equal to or larger than the stacking height (thickness).

In the magnetic core with a gap according to the present invention,
The length TA of the spacer is preferably 1.05 times or more, and particularly preferably 1.1 to 2.0 times the stacking height (thickness) of the annular stack.

As a result, all the amorphous magnetic ribbons are firmly fixed to the spacer 3 with an adhesive (407, cyanoacrylate, epoxy resin, silicone, etc. manufactured by Loctite).

The length TB of the spacer with respect to the width of the amorphous alloy ribbon can be the same as the width of the ribbon or smaller than the width of the ribbon. The reason is that even if the spacer length TB with respect to the width of the amorphous alloy ribbon is not made larger than the ribbon width, the spacer length TA with respect to the stacking height (thickness) of the annular laminate is This is because all of the amorphous magnetic ribbons are fixed to the spacer 3 with an adhesive because the lamination height (thickness) is equal to or larger than the lamination height (thickness).

The toroidal coil 5 used in an electric circuit is completed by insulating the magnetic core with a gap thus created and winding the vinyl coated wire 4 of 0.5 mmφ around the magnetic core.

The following Examples 1-4 and Comparative Examples 1-2 are:
When the toroidal coil 5 is incorporated in an electric circuit and is operated by passing an alternating current, the noise generated from the magnetic core 1 is measured under a constant condition.

[0033]

Example 1 As shown in FIGS. 3 and 4, the composition is Fe ₇₈ B ₁₃
10 m of an amorphous alloy ribbon made of Si ₉ (numerical value is atomic%) (trade name: Methograss 2605S2 manufactured by Allied Co., Ltd.)
After slitting so as to have a width of m, it was wound 500 times to prepare a magnetic core 1 having an inner diameter of 15 mm, an outer diameter of 25 mm, and a stacking height (thickness) of 5.0 mm of amorphous alloy ribbons.

Next, the magnetic core 1 is subjected to 2 at a temperature of 380.degree.
Annealed in nitrogen atmosphere for only time. The annealed magnetic core 1
Between the thin strips of the wound body of synthetic resin (TB2 manufactured by Three Bond Co., Ltd.
287, glass melting point 65 ° C.) was impregnated and the annular laminate was adhered.

To form a gap in the magnetic core 1, a part of the magnetic path of the annular laminated body forming the magnetic core 1 is cut by a cutting machine. The gap thus provided had a slit width of 0.5 mm, and the cut dimensions were a stacking height (thickness) of 5.0 mm and a width of the ribbon of 10.0 mm.

The spacer 3 to be inserted into the gap
After laminating glass fiber and impregnating with epoxy resin,
Annealed in a nitrogen atmosphere at a temperature of 380 ° C. for 2 hours,
It is cured and manufactured.

Here, as for the size of the spacer 3, as shown in FIGS. 3 to 4, the length TA with respect to the stacking height (thickness) of the annular stacked body is 5.0 mm and the width with respect to the width of the amorphous alloy ribbon. The length TB was 10.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular laminate is 1.0 times the stacking height (thickness) of the annular laminate. Next, the spacer 3 was inserted into the gap 2, and was closely attached to the cut surface and bonded to the magnetic core 1 with an adhesive (407 made by Loctite Corporation).

The toroidal coil 5 was prepared by winding the vinyl coated wire 4 having a diameter of 0.5 mm for 30 turns on the magnetic core with a gap thus prepared. An alternating current was passed through the toroidal coil 5 to measure the noise generated from the gapped magnetic core 1. The measurement conditions are as follows.

Noise measurement conditions Signal amplitude: 10 Ap-p Signal offset: 5 A (ampere) Signal frequency: 500 Hz (hertz) to 20 kHz (kilohertz) Sweep time: 1.0 second / reciprocating microphone distance: 200 mm Magnetic core temperature: 110 ° C. As a result, the noise level was 60 dB (decibels).

[0041]

[Embodiment 2] Next, the same toroidal coil 5 as in Embodiment 1 is prepared, and the spacer 3 has a spacer 3 with respect to the stacking height (thickness) of the annular stack as shown in FIGS.
Has a length TA of 5.0 mm, and the length TB of the spacer 3 with respect to the width of the amorphous alloy ribbon is 5.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular stacked body is 1.0 times the stacking height (thickness) of the annular stacked body. An alternating current was passed through the toroidal coil 5, and noise was measured under the same measurement conditions as in Example 1. As a result, the noise level is 6
It became 1 dB (decibels).

[0043]

Third Embodiment In the third embodiment, the same toroidal coil 5 as in the first embodiment is produced, and the spacer 3 has a size corresponding to the stacking height (thickness) of the annular stack as shown in FIGS. Has a length TA of 7.0 mm and the length TB of the spacer 3 with respect to the width of the amorphous alloy ribbon is 10.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular stacked body is 1.4 times the stacking height (thickness) of the annular stacked body. An alternating current was passed through the toroidal coil 5, and noise was measured under the same measurement conditions as in Example 1. As a result, the noise level is 6
It became 0 dB (decibels).

[0045]

[Embodiment 4] In Embodiment 4, the same toroidal coil 5 as in Embodiment 1 is prepared, and the size of the spacer is, as shown in FIGS. 9 to 10, the spacer 3 with respect to the stacking height (thickness) of the annular stack. Has a length TA of 5.0 mm and a spacer length TB with respect to the width of the amorphous alloy ribbon of 15.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular stacked body is 1.0 times the stacking height (thickness) of the annular stacked body. An alternating current was passed through the toroidal coil 5, and noise was measured under the same measurement conditions as in Example 1. As a result, the noise level is 6
It became 0 dB (decibels).

[0047]

COMPARATIVE EXAMPLE 1 In contrast to Examples 1 to 4 described above, in Comparative Example 1, the same magnetic core with a gap as in Example 1 was prepared, and the size of the spacer was set as shown in FIGS. The length TA of the spacer 3 with respect to the height (thickness) is 4.0 mm
And the length T of the spacer 3 with respect to the width of the amorphous alloy ribbon.
B was 10.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular laminate is 0.8 times the stacking height (thickness) of the annular laminate. Then, in Comparative Example 1, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular stack is shortened by 1.0 mm with respect to the stacking height (thickness) of 5.0 mm, and all amorphous magnetic The ribbon is not fixed to the spacer 3.

An alternating current was passed through the toroidal coil 5, and noise was measured under the same measurement conditions as in Example 1.
As a result, the noise level was 70 dB (decibels).

[0050]

[Comparative Example 2] In Comparative Example 2, the same toroidal coil 5 as in Example 1 was prepared, and the size of the spacers was set as shown in FIGS.
As shown in, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular laminate was 3.0 mm, and the length TB of the spacer 3 with respect to the width of the amorphous alloy ribbon was 10.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular laminate is 0.6 times the stacking height (thickness) of the annular laminate. Then, in Comparative Example 2, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular stack is shortened by 2.0 mm with respect to the stacking height (thickness) of 5.0 mm, and all amorphous magnetic The ribbon is not fixed to the spacer 3.

An alternating current was passed through the toroidal coil 5, and noise was measured under the same measurement conditions as in Example 1.
As a result, the noise level was 75 dB (decibels). The following is a table of the measurement results of Examples 1 to 4 and Comparative Examples 1 and 2.

[0053]

[Table 1] As is clear from the above measurement results, by making the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular stacked body the same as the stacking height (thickness) or larger than the stacking height (thickness), It can be seen that the noise level is suppressed to 60 to 61 dB, while the noise level is expanded to 70 to 75 dB when the height is made smaller than the stacking height (thickness).

It is understood that the noise level is not affected even if the length TB of the spacer 3 with respect to the width of the amorphous alloy ribbon is equal to or smaller than the width of the ribbon.

[0055]

Fifth Embodiment In a fifth embodiment, as shown in FIG. 15, the gap-carrying magnetic core 5 according to the first embodiment is housed in a case 6 in which fibers are planted, and is a case-housing type magnetic core.

In the fifth embodiment, the size of the spacer 3 is such that the length TA with respect to the stacking height (thickness) of the annular stack is 5.0 mm and the length TB with respect to the width of the amorphous alloy ribbon.
Was set to 10.0 mm.

Therefore, the length TA of the spacer 3 with respect to the stacking height (thickness) of the annular laminate is 1.0 times the stacking height (thickness) of the annular laminate.

[0058]

According to the present invention, even if the temperature of the magnetic core rises and the adhesive for fixing the laminated body is softened, all the amorphous magnetic ribbons are adhesive (Loctite 407). Since it is fixed to the spacer, vibration of the magnetic core is suppressed by the spacer, and noise generation can be suppressed to a minimum.

Particularly, in the case-storing type magnetic core of the fifth embodiment,
Since the magnetic core with a gap is housed in the case, the noise reduction effect of the case is added, and the noise generated from the magnetic core can be further suppressed.

Since the length of the spacer with respect to the width of the amorphous alloy ribbon can be made smaller than the width of the ribbon, the manufacturing cost of the spacer can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a conventional magnetic core with a gap.

FIG. 2 is a sectional view of a conventional magnetic core with a gap and a plan view of a spacer.

FIG. 3 is a perspective view of a magnetic core with a gap according to the first embodiment.

FIG. 4 is a sectional view of a magnetic core with a gap and a plan view of a spacer according to the first embodiment.

5 is a perspective view of a magnetic core with a gap according to the second embodiment. FIG.

FIG. 6 is a sectional view of a magnetic core with a gap and a plan view of a spacer according to the second embodiment.

FIG. 7 is a perspective view of a magnetic core with a gap according to the third embodiment.

FIG. 8: a sectional view of a magnetic core with a gap and a plan view of a spacer according to a third embodiment.

FIG. 9 is a perspective view of a magnetic core with a gap according to the fourth embodiment.

FIG. 10 is a sectional view of a magnetic core with a gap and a plan view of a spacer according to a fourth embodiment.

11 is a perspective view of a magnetic core with a gap according to Comparative Example 1. FIG.

12 is a sectional view of a magnetic core with a gap and a plan view of a spacer according to Comparative Example 1. FIG.

13 is a perspective view of a magnetic core with a gap according to Comparative Example 2. FIG.

14 is a sectional view of a magnetic core with a gap and a plan view of a spacer according to Comparative Example 2. FIG.

FIG. 15 is a perspective view of a case storage type magnetic core according to the fifth embodiment.

[Explanation of symbols]

 1 ... Magnetic core 2 ... Gap 3 ... Spacer 4 ... Vinyl coated wire 5 ... Toroidal coil 6 ... Case TA ... Spacer length to stack height (thickness) TB ... Spacer length to ribbon width

Claims (8)

[Claims] 1. A magnetic core comprising an annular laminated body wound with a magnetic ribbon, and a gap formed by cutting the annular laminated body in a magnetic path of the magnetic core, and a spacer is inserted into a cut surface of the gap. In the magnetic core with a gap, in which the spacer is brought into close contact with the cut surface and adhered to the magnetic core with an adhesive, the length of the spacer with respect to the stacking height (thickness) of the annular stacked body forming the magnetic core with the gap is the stacking height ( Thickness)
A magnetic core with a gap that is the same as or larger than the stack height (thickness). 2. The magnetic core with a gap according to claim 1, wherein the magnetic core has a cylindrical shape. 3. The magnetic core with a gap according to claim 1, wherein the spacer is a spacer in which glass fibers are laminated. 4. The spacer is formed by laminating glass fibers,
The magnetic core with a gap according to claim 1, which is a spacer formed by impregnating and curing an epoxy resin. 5. The magnetic core with a gap according to claim 1, wherein the magnetic ribbon is a magnetic ribbon made of an amorphous magnetic alloy. 6. The length of the spacer is in the range of 1.0 to 2.0 times the stacking height (thickness) of the annular stack.
Magnetic core with a gap as described. 7. A magnetic core comprising an annular laminated body wound with a magnetic ribbon, and a gap formed by cutting the annular laminated body in the magnetic path of this magnetic core, and a spacer is inserted into the cut surface of this gap. In a magnetic core with a gap in which a spacer is closely adhered to the cut surface and is adhered to the magnetic core with an adhesive, a length that is the same as or greater than the laminated height (thickness) that constitutes this magnetic core with a gap as a spacer. A magnetic core with a gap that suppresses noise, characterized by using the spacer of 1. 8. The magnetic core with a gap according to claim 7, wherein the magnetic core is cylindrical and the spacer is a spacer formed by laminating glass fibers.