JP2685077B2 - Winding iron core for transformer and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wound core for a transformer and a method for manufacturing the same.

[Conventional technology]

In recent years, in power transformers and the like, while transmitting only necessary power, blocking unnecessary and harmful noise components,
A function of protecting an electronic circuit from the noise is required.

Since the above-mentioned noise component is usually a high frequency, the following method is available as a measure for blocking the noise.

1) A method using an iron core that has a large loss with respect to a high frequency and a low magnetic permeability.

2) A method in which the distance between the primary coil and the secondary coil is increased to lengthen the magnetic path of the iron core between them.

3) A method of strictly performing electrostatic shield between the primary coil and the secondary coil.

4) A method that combines some of the above methods.

[Problems to be solved by the invention]

However, in any of the above-mentioned methods, finally, the primary side coil and the secondary side coil as the air-core coil are coupled by electromagnetic induction according to Farade's law, and this transmits a noise component to each other. Cause the phenomenon of doing.

_Known arrangements of the primary side coil W ₁ (W _1a , W _1b ) and the secondary side coil W ₂ (W _2a , W _2b ) as air-core coils are shown in FIGS. 7 (A) to (D). To be Primary coil W ₁
The strength of the magnetic coupling between (W _1a , W _1b ) and the secondary coil W ₂ (W _2a , W _2b ), that is, the primary coil W ₁ (W _1a , W _1b ) and the secondary coil W Mutual inductance M with ₂ (W _2a , W _2b ) is
The arrangement shown in FIG. 7 (A), the arrangement shown in FIG. 7 (B), the arrangement shown in FIG. 6 (C), and the arrangement shown in FIG. 7 (D) become smaller in this order, but the arrangement shown in FIG. The magnetic coupling is still large,
Inadequate as a measure to block noise.

Therefore, an object of the present invention is to provide a wound iron core (iron core) for a transformer in which magnetic coupling between the primary coil and the secondary coil when viewed as an air-core coil is small.

Another object of the present invention is to provide a method for manufacturing the above iron core.

[Means for solving the problem]

The means for solving the above-mentioned problem is shown in FIG. That is, the generated magnetic flux center lines L ₁ and 2 of the primary coil W ₁
And generating magnetic flux center line L ₂ of the next coil W ₂ Consider the air core coil such that the right angle. In this case, the generated magnetic flux of the primary coil W ₁ hardly interlinks with the secondary coil W _2, and
The generated magnetic flux of the secondary coil W ₂ hardly interlinks with the primary coil W _1, and therefore the primary coil as an air-core coil
The magnetic coupling between W ₁ and the secondary coil W ₂ is small, so that the high frequency noise transfer between these coils is small.

The present invention provides a transformer winding core (transformer iron core) that realizes the coil arrangement shown in FIG. 1. Therefore, the transformer core according to the present invention is formed by winding an iron core band material, The transformer winding core is formed by enlarging the difference between the outer peripheral length and the inner peripheral length at a predetermined ratio and twisting the wound core core material to twist the primary winding winding portion and the secondary winding winding portion. And are formed substantially at right angles.

Further, in order to manufacture the above-mentioned transformer core, a winding core in which the difference between the outer circumference length and the inner circumference length is enlarged at a predetermined ratio is prepared, and the winding core is twisted to form the primary winding W ₁ Direction of the magnetic flux in the part where the coil is wound and the secondary winding W ₂
It is manufactured so that the direction of the center of the magnetic flux in the wound portion is substantially perpendicular.

(Operation)

According to the above means, the primary coil W ₁ and the secondary coil
When W ₂ is wound around the iron core, the magnetic coupling when acting as an air-core coil becomes small.

〔Example〕

FIG. 2 is a diagram showing an embodiment of a winding core for a transformer (iron core for a transformer) according to the present invention, and FIG. 3 is a diagram showing the primary coils W ₁ and 2 for each of the iron cores 1, 2, 3 in FIG. is a diagram which made turning to wind the next coil W _2. In any of FIGS. 3A to 3C, the center line of the magnetic flux generated by the primary coil W ₁ and the secondary coil
It is at right angles to the central direction of the generated magnetic flux of W ₂ . Therefore, in FIGS. 3A to 3C, when the iron cores 1, 2, and 3 are removed, that is, the primary side coil as the air-core coil is removed.
The magnetic coupling between W ₁ and the secondary coil W ₂ is small.

When the iron core shown in FIG. 2 is manufactured, the wound iron core shown in FIG. 4 (A) is prepared, and then the parts A and B are each sandwiched by a tool (not shown) of a twisting means, It is considered that the iron cores 1, 2, and 3 shown in Fig. 2 can be obtained by applying twisting around the center of twist. However, during the twisting process, the iron core inner window portion (right angle portion) shown in FIG. 4 (A) needs to be bent at an angle much smaller than 90 ° as shown in FIG. 4 (B). is there. Therefore, the arrows X and Y in FIG.
As shown in Fig. 4, the outer peripheral side needs to be longer than the inner peripheral side. Therefore, the winding core in the state of Fig. 4 (A) is twisted to form the winding core of Fig. 2 (A), (B) or It is almost impossible to obtain a wound iron core as shown in (C).

Therefore, in the present invention, FIG. 2 (A), (B),
Alternatively, in order to manufacture the wound cores 1, 2 or 3 shown in (C), the wound core shown in FIG. 5 is prepared. That is, the difference between the inner peripheral length and the outer peripheral length is enlarged at a predetermined ratio. As a result, when the winding core shown in FIG. 5 is twisted around the torsion center as an axis, the winding core shown in FIG. 2 (A), (B) or (C) is obtained.

As shown in FIG. 6A, a specific method for obtaining the wound iron core of FIG. 5 is as follows.
A resin tape (not shown) is sandwiched and wound up, and the paper, tape, etc. are removed before the winding iron core is twisted. It should be noted that, instead of the above-mentioned paper, tape, etc., a wax (paraffin) -like substance is applied to the core band material with a predetermined thickness and wound up, and even after the winding up, this applied layer is melted by heating or dissolved and removed by a solvent. Good.

Further, as another specific method, as shown in FIG. 6B, an elongated jig that defines a predetermined inner circumferential length is prepared, and the iron core band material is wound around the jig slightly.

〔The invention's effect〕

As described above, the transformer winding iron core (transformer iron core) according to the present invention has a small magnetic coupling when it is considered as an air-core coil when the primary winding and the secondary winding are provided. Yes, so there is good isolation of noise between them.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a principle configuration of the present invention, FIG. 2 is a diagram showing an embodiment of a transformer iron core according to the present invention, and FIG. 3 is one for each iron core of FIG. Drawings with secondary coil and secondary coil, Figure 4, Figure 5, Figure 6A, and Figure 6B are figures for explaining the method of manufacturing the iron core for transformer according to the present invention, and Figure 7 is general. It is a figure explaining arrangement | positioning of the primary side coil and secondary side coil as an air core coil. W ₁ , W _1a , W _1b …… Primary coil, W ₂ , W _2a , W _2b …… Secondary coil, 1,2,3 …… Iron core, 4 …… Jig.

Claims (5)

(57) [Claims] 1. A winding core for a transformer, which is formed by winding an iron core band material, wherein the difference between the outer peripheral length and the inner peripheral length is enlarged at a predetermined ratio to twist the wound core core material. A winding core for a transformer, characterized in that the winding portion of the secondary winding and the winding portion of the secondary winding are formed substantially at right angles. 2. A primary winding (W ₁ ) of the wound core is prepared by preparing a wound iron core in which the difference between the outer peripheral length and the inner peripheral length is enlarged at a predetermined ratio and twisting the wound iron core. A method of manufacturing a wound core for a transformer, characterized in that the direction of the magnetic flux in the portion around which the coil is wound and the direction of the magnetic flux in the portion around which the secondary winding (W ₂ ) is wound are made substantially at right angles. 3. The wound core is formed by sandwiching and winding a paper or tape having a predetermined thickness at the time of winding and forming an iron core band material, and the paper or tape before the twisting process is applied to the wound core. The method of manufacturing a wound core for a transformer according to claim 2, wherein 4. The winding iron core for a transformer according to claim 2, wherein the winding iron core is formed by slightly winding the iron core band material on an elongated jig when winding and forming the iron core band material. Production method. 5. The winding core for a transformer according to claim 2, wherein the winding core is configured such that a wax-like substance is heated and melted or melted and removed when winding and forming the core band material. Method.