JPH043095B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for manufacturing a wound core, and more specifically, when manufacturing a wound core using a pre-wound tape, a method for manufacturing a wound core that is unnecessary for the magnetic performance of the wound iron core is used. The present invention relates to a method of manufacturing a wound core by removing a pre-wound tape very easily.

[Technical Background of the Invention and Problems Therein] Currently, wound cores, which are often used in Chiyoke coils, etc., are generally made by winding a magnetic conductor for the core multiple times around a winding form of a desired diameter, and then sealing the ends with adhesive or the like. Manufactured by gluing and fixing.

Conventionally, silicon steel,
Magnetic thin bodies such as permalloy and ferrite were used, but recently, for the purpose of improving the magnetic properties of the iron core, thin bodies of amorphous magnetic alloys manufactured by the liquid quenching method have been used as magnetic thin bodies. is attracting attention.

When this amorphous magnetic alloy is made into a thin body, it exhibits extremely large spring elasticity. There was a problem in that it was difficult to smoothly wind the winding start portion according to the curvature of the winding form.

As a countermeasure to this problem, conventionally, a heat-resistant tape such as polyimide tape is first wound multiple times around the winding form, and the first end of the amorphous magnetic alloy thin body (the beginning of winding) is placed at the end of the first wound tape. ) and then wound them continuously to manufacture a wound core.

When manufacturing wound cores using this method, the pre-wound tape used for forming is not necessary for the core after forming, so the pre-wound tape is usually removed before and after the heat treatment process to remove distortion. There was a process in place to do so. However, since this removal step is performed manually, the work efficiency is extremely low, such as the inability to process a large amount at once, resulting in problems such as increased manufacturing costs.

In addition, polyimide tape has traditionally been widely used as first-wound tape due to its flexibility, but
This polyimide tape is 20m long due to its physical properties.
However, depending on the number of pre-wraps, it was necessary to connect multiple tapes together. Because of this, it is inferior in terms of workability,
There were also other problems, such as higher prices.

[Object of the Invention] The present invention solves the above problems, and by using a thermoplastic resin tape as the pre-wound tape, the thermoplastic resin tape can be easily removed from the iron core after molding. The purpose of the present invention is to provide a method for manufacturing a wound core.

[Summary of the Invention] In order to achieve the above object, the present inventors have conducted intensive research and found that the pre-wrap tape used in manufacturing the wound core was conventionally removed by hand; He came up with the idea that if a tape made of a thermoplastic resin that decomposes thermally is used as the pre-wrapping tape, this tape could be easily evaporated and removed during the heat treatment process after core forming, and this led him to complete the present invention. It has arrived.

That is, in the manufacturing method of the present invention, a pre-wound tape made of a thermoplastic resin tape is wound around a winding former, and a magnetic thin body for an iron core connected to the terminal end of the pre-wound tape is further continuously wound. After the core is formed, the wound core is heat-treated at a temperature higher than the thermal decomposition temperature of the thermoplastic resin constituting the first-wound tape.

The manufacturing method of the present invention will be described below with reference to FIGS. 1 and 2.
This will be explained based on the diagram.

As shown in FIG. 1, after winding the thermoplastic resin tape 1 around the winding form 4 an arbitrary number of times, a second
The initial end portion (the beginning of winding) of the magnetic thin body 2 for iron core shown in the figure is connected by means such as adhesive or sandwiching, and then the wound core 3 is formed by continuously winding it a predetermined number of times. can do.

The thermoplastic resin tape 1 used here is not particularly limited as long as it can be evaporated and removed by heat treatment during distortion removal, but polypropylene tape is particularly preferred. Further, the shape such as the thickness of the tape, the number of turns, etc. can be appropriately selected depending on the intended magnetic properties of the wound core.

Further, as the magnetic thin body 2 for the iron core, a thin body made of an amorphous magnetic alloy is preferable from the viewpoint of the magnetic properties of the iron core. In this case, the amorphous magnetic alloy is Co
Examples include Fe-based alloys, Fe-based alloys, Fe-Ni-based alloys, and the like.

After forming the wound core 3 in the above-described manner, the end portion of the core magnetic thin body 2 constituting the wound core 3 is fixed with an adhesive or the like, and then heat-treated at a temperature equal to or higher than the decomposition temperature of the thermoplastic resin tape 1 used. By doing so, the previously wound thermoplastic resin tape 1 can be evaporated and removed.

The heat treatment in this case is carried out at a temperature higher than the thermal decomposition temperature of the thermoplastic resin tape 1 used as described above, but for example, if a polypropylene tape is used, it may be heated at about 400 to 500°C for 30 to 60 minutes. . Heat treatment is performed to remove this pre-wrapped tape.
There is no need to create a new processing step for this purpose.
It can be performed at the same time as conventional heat treatment for straightening the core.

After the heat treatment, a wound core can be obtained by further performing epoxy coating or case packing.

[Embodiments of the invention] Hereinafter, the present invention will be explained in further detail with reference to Examples.

Example 1 A polypropylene tape with a thickness of 50 μm was wound several tens of times around a winding form, and then the first end of a strip-shaped Co-based amorphous magnetic alloy thin body was attached to the end of the polypropylene tape, and then the tape was continuously wound. and then wind the outer diameter
A wound core with a diameter of 20 mm, an inner diameter of 14 mm, and a height of 5 mm was formed.
After molding, heat treatment was performed at 400°C for 30 minutes in nitrogen gas. As a result, the polypropylene tape was completely evaporated and removed, leaving no residue at all. After heat treatment, epoxy coating was applied to obtain a wound core. The obtained wound core was tested for its AC magnetic properties. The characteristic value at 50kHz is
The coercive force (Hc) is 0.160, the squareness ratio (Br/B ₁ ) is 97%, and the characteristic values of a wound core of the same dimensions (Hc: 0.162,
Br/B ₁ :97%).

[Effects of the Invention] As described above, in the manufacturing method of the present invention, a thermoplastic resin tape is used as the pre-wound tape, and this thermoplastic resin tape can be processed normally without adding any special processing steps. By the heat treatment for strain relief, the magnetic thin body can be easily evaporated and removed at the same time as strain relief. This makes it possible to process a large amount at once, shortening manufacturing time and reducing manufacturing costs. Furthermore, thermoplastic resin tapes, such as polypropylene tapes, can be made much longer than conventionally used polyimide tapes, so even when the number of turns of a winding form is large, multiple tapes can be used. Since there is no need to connect tapes together and the price is low, it has extremely great industrial value.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are diagrams for explaining the steps of the manufacturing method of the present invention, respectively.

Claims (1)

[Scope of Claims] 1. A pre-wound tape made of a thermoplastic resin tape is wound around a winding former, and a magnetic thin body for iron core connected to the terminal end of the pre-wound tape is further continuously wound to form a wound iron core. A method for manufacturing a wound core, characterized in that the wound core is subjected to heat treatment at a temperature equal to or higher than the thermal decomposition temperature of the thermoplastic resin constituting the first-wound tape. 2. The method according to claim 1, wherein the pre-wound tape is a polypropylene tape. 3. The method according to claim 1, wherein the magnetic thin body for iron core is an amorphous magnetic alloy thin body.