JP2014093416A - Method of manufacturing magnetic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a magnetic member, which does not use a construction method requiring costs of sintering at a high temperature, cutting using a high-hardness blade and the like, and which uses a molding method enabling a fine shape change.SOLUTION: A powdery magnetic material is infilled into a mold or a casing, and a binder is injected into the mold or the casing and hardened.

Description

  The present invention relates to a method for manufacturing a magnetic member.

  A member having magnetism used for a core material of a magnet, an electromagnetic coil, or the like is conventionally a method in which a magnetic material such as ferrite, permalloy, or amorphous is placed in a metallic mold and sintered at a high temperature (for example, Patent Document 1). ), A method of mixing a powdered magnetic substance into an organic resin or the like, and a method of cutting a plate-like material such as a silicon steel plate (for example, Patent Document 2).

  However, for example, it is possible to adjust the output Gauss by finely adjusting the shape of the core material of the electromagnetic coil, but it may be necessary to produce many prototypes when finely adjusting the shape. . Moreover, when using a bobbin-less coil, it is necessary to change the shape of the core material used suitably according to the shape of the coil. In that case, in order to sinter, many molds are required to produce many types of core materials, which is problematic in terms of cost. Further, when sintering is performed, the volume is reduced, so that there is a problem that accurate mold design is difficult. Also in cutting, in order to cut a silicon steel plate having a high hardness, it is necessary to use a blade having a higher hardness, which is also expensive. A resin mixed with a powdery magnetic substance has a very high viscosity when the amount of magnetic particles is increased in order to increase the magnetic flux density. For example, it is poured into a resin mold and molded. It was difficult to remove, and it was difficult to change the shape. On the other hand, if the amount of magnetic particles used for improving the moldability is reduced, a problem that a desired magnetic flux density cannot be obtained may occur.

JP 2003-86430 A JP-A-6-246309

  The present invention provides a method for producing a magnetic member without using a costly construction method such as sintering at high temperature or cutting using a blade with high hardness, and using a molding method capable of minute shape change. The purpose is to do.

  The method for producing a magnetic member according to the present invention includes a step of filling a mold or casing with a powdered magnetic substance and a step of injecting a binder into the mold or casing. According to the present invention, by filling a mold or casing with fine magnetic substance powder having no viscosity, it becomes possible to put the magnetic substance at a high filling rate regardless of the viscosity of the binder. It is possible to ensure the magnetic flux density. Here, the binder between the powders can be bonded by injecting the binder into a mold or casing filled with the powders.

  The viscosity of the binder is preferably 250 mPa or less. By injecting a sufficiently low-viscosity binder into a powder-filled mold or casing, the binder can be sufficiently distributed in the gaps between the powders, and the bonding between the powders can be made more reliable. it can.

  The filling rate of the magnetic substance in the mold or casing is preferably 90 to 98%. By setting the filling rate of the magnetic substance to 90% or more, a high magnetic density of the magnetic member can be secured, and by setting the filling rate to 98% or less, the bonding between the powders by the binder is ensured. It becomes possible to do.

  The powdery magnetic substance preferably has an average particle size of 200 mesh or less. By setting it as the said particle size, a high filling rate is implement | achieved and sufficient penetration of a binder can be enabled.

  The mold or casing is preferably made of at least one material selected from the group consisting of wood, resin, iron and other soft magnetic materials. According to the method for producing a magnetic member of the present invention, high temperature treatment such as sintering is not required. Therefore, it is possible to use a soft magnetic material such as wood, resin, iron tube, or iron plate that is cheaper and easier to process than the mold for the mold or casing, and the manufacturing cost can be greatly reduced.

  The magnetic member of the present invention is manufactured using any one of the above-described magnetic member manufacturing methods. By using the above method, it is possible to obtain a magnetic member having a sufficiently high magnetic flux density and capable of fine shape change without undergoing a high temperature sintering or hardness cutting process.

  The magnetic member is preferably a core material of an electromagnetic coil. By making it possible to finely change the shape of the core material of the electromagnet coil, the size and direction of the magnetic flux density of the electromagnet can be finely adjusted. The core material is preferably a bobbinless coil core material. Since the present invention enables a minute shape change of the magnetic member, a core material suitable for various bobbinless coils to be used can be appropriately manufactured.

  The magnetic member is preferably a permanent magnet. Thereby, it becomes possible to change the shape of a permanent magnet minutely, and it becomes possible to use a permanent magnet for a wider use.

  According to the present invention, a method for producing a magnetic member using a molding method capable of fine shape change without using a costly construction method such as sintering at high temperature and cutting using a blade having high hardness. Can be provided.

It is the top view which shows an example of the core material of a pot-type electromagnet coil, and an AA sectional view. It is the schematic which shows 1st Embodiment of the manufacturing process of the magnetic member of this invention. It is the top view, BB sectional view, and CC sectional view which show two manufacture examples of the permanent magnet manufactured using the manufacturing method of the magnetic member of this invention.

  The present invention includes a method of manufacturing a magnetic member, comprising: filling a mold or casing with a powdery magnetic substance; and pouring a binder into the mold or casing. Provided is a magnetic member manufactured.

<Core material of electromagnetic coil>
The magnetic member manufactured using the manufacturing method of the magnetic member of this invention can be used as a core material of an electromagnet coil. The use of the electromagnet is wide and not particularly limited. Hereinafter, the core material used for the electromagnet of the AC magnetic therapy device will be exemplified.

  In general, an AC magnetic therapy device uses a 100V AC power supply for general households, generates magnetism electrically with a plurality of built-in electromagnets, stimulates the human body with magnetism, and treats poor blood circulation. It is a treatment device that gives This is an application of magnetism (alternating magnetic field) that alternately flies in a large arc while changing the polarity 50/60 times per second depending on the frequency. The magnetic flux density (Gauss) output from the AC magnetic therapy device is a guideline for the therapeutic effect. That is, the higher the Gaussian output, the higher the therapeutic effect generally. However, in Japan, the AC magnetic therapy device for home use is certified by the Ministry of Health, Labor and Welfare, and the output level must be within the range of 35 to 180 mT. Therefore, in order to maximize the effect of the home AC magnetic therapy device, it is necessary not to exceed 180 mT but as close as possible to 180 mT.

  The adjustment of the output gauss of the electromagnet may be made by changing the material of the coil and the core material, the thickness of the coil, the number of turns, etc., but it is also possible to change the shape of the core material. Here, for example, as shown in FIG. 1, it is possible to increase the output Gauss in a certain direction by making the core material 11 of the electromagnet into a so-called pot shape. Thus, by changing the form of the core material as appropriate, it is possible to adjust the output gauss, the direction of the magnetic flux, and the like.

  As the electromagnet coil, a bobbinless coil is widely used in accordance with its application. In general, the shorter the distance between the coil and the core material, the higher the output. Therefore, it is possible to form a higher output electromagnet by appropriately changing the shape of the core to a shape suitable for the coil.

<Manufacturing method of core material>
Hereinafter, the method for producing a magnetic material of the present invention will be outlined by illustrating a method for molding a core material.

(1. Casing)
When manufacturing the core material, a mold or a casing is used. Hereinafter, an embodiment using a casing will be described with reference to the drawings.
The material of the casing is not particularly limited as long as it does not directly affect the magnetism, is hardly changed by the binder described later, and can be easily processed. In particular, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyethylene Resins such as terephthalate, polyester, ethylene-vinyl acetate copolymer (EVA), nylon, ABS, polycarbonate, polyetherimide, and Teflon (registered trademark) can be suitably used. Moreover, you may use soft magnetic materials, such as an iron tube and an iron plate. The thickness of the casing is preferably 0.5 to 2.0 mm, particularly preferably 0.5 to 1.0 mm. By setting the thickness to 0.5 to 2.0 mm, it is difficult to affect the magnetism and can have sufficient strength.
In addition, when using a type | mold, the same raw material can be used conveniently, However The restriction | limiting in particular is not required for the thickness. Moreover, when using a mold | type, it is also possible to use as a raw material the wood which is easy to process and is cheap.

(2. Magnetic substance)
Specifically, a soft magnetic material is suitable as the magnetic material used for the core material, and iron, permalloy, soft ferrite, sendust, permendur, amorphous, silicon steel, and the like can be suitably used. These magnetic substances may be used alone or in combination of two or more. The magnetic substance is preferably used as a powder having an average particle diameter of 200 mesh or less, particularly 170 to 200 mesh. By setting the average particle size to 200 mesh or less, there is an advantage that the filling rate into the casing can be increased and finer molding becomes possible. On the other hand, when the average particle size is less than 0.025 μm, it may cause a problem that it is difficult to produce the powder itself. The particle size of the magnetic substance powder does not need to be uniform, and the filling rate described later can be further increased by appropriately combining large and small particle sizes.

(3. Binder)
The binder that binds between the powders of the magnetic substance is not particularly limited as long as it has a certain level of affinity with the magnetic substance. Organic binders (epoxy, acrylic, urethane) , Vinyl acetate type, cellulose type, etc.) and inorganic binders (alkali metal silicate type, phosphate type, silica sol type, ceramic type, etc.) can be used. It is necessary to use a material that can bind the powder without any problems. These binders may be used independently and may be used in mixture of multiple types. Further, a solvent such as thinner may be added to adjust the viscosity and the like. As the binder, it is preferable to use a binder having a viscosity of 250 mPa or less, particularly 150 to 250 mPa, because the powder filling rate described later can be increased.

(4. Other materials)
A filler such as silica may be added together with the powdery magnetic substance. Moreover, you may mix | blend components, such as a reinforcing material, a hardening | curing agent, a ultraviolet absorber, an additive, antioxidant, and anti-aging agent suitably with a binder.

(5. Manufacturing process of core material)
A first embodiment of the core material manufacturing process will be described with reference to FIG. First, the casing 21 is manufactured and prepared in accordance with the desired form of the core material (FIG. 2A). The casing 21 can be manufactured by a known method according to the material to be used. For example, when using resin as a raw material, it can be manufactured by injection molding or cutting.

  A powdery magnetic substance 22 is sealed in the casing 31 (FIG. 2B). At that time, it is preferable that the filling rate of the magnetic substance is 90 to 98%, particularly 95 to 98%. By setting the filling rate to 90% or more, a high-Gaussian electromagnet can be manufactured, and by setting the filling rate to 98% or less, the penetration of the binder and the bonding between the powders are further ensured.

  A binder is injected into the casing 21 enclosing the magnetic material 22 at a low speed so as to penetrate into the powder of the magnetic material, thereby forming a mixture 23 of the binder and the magnetic material in the casing 21 (FIG. 2C). . Although not shown, it is preferable that the casing 21 has a structure in which air holes are formed in the upper portion in advance and the binder is injected from the vicinity of the bottom of the casing so that the bubbles in the powder escape to the upper portion along with the injection of the binder. Furthermore, it is good also as a structure where a compressor etc. are connected to an air hole and air tends to escape from upper part.

  The core material is formed by curing the injected binder. Here, when a mold is used instead of the casing, it is necessary to remove the mold after the binder is cured. In this case, it is preferable to subject the surface of the core material removed from the mold to a curing treatment and further to an insulation treatment as necessary.

<Method for manufacturing permanent magnet member>
The method for producing a magnetic member of the present invention can be used not only for the core material of an electromagnet but also for the production of a permanent magnet member. As permanent magnets, plastic magnets, rubber magnets and other resins, and rubber materials in which magnetic substance particles are mixed are already widely known. These are flexible, easy to mold, lightweight, etc. Has the advantage of However, since the presence rate of magnetic substances is generally low, it has been difficult to obtain a high Gauss magnet. According to the present invention, it is possible to manufacture a permanent magnet that is high gauss and that can be finely modified.

In the production of the permanent magnet member, a hard magnetic material such as ferrite, alnico, or neodymium can be suitably used as the magnetic substance.
The mold or casing to be used, the binder, other materials, and the production method are the same as those for the core material.

  3 (a) and 3 (b) show top views, BB cross-sectional views, and CC cross-sectional views of two examples of manufacturing a permanent magnet using a mold according to the method of manufacturing a magnetic member of the present invention. It is a thing. A strong permanent magnet 31 having such a fine structure can be manufactured by using a mold, a magnetic substance powder, and a binder without performing high temperature sintering, cutting with a high hardness blade, or the like. .

  The method for producing a magnetic member of the present invention can be used in any industrial field that requires a member having both magnetism and a fine shape. For example, it can be used for the production of members of daily necessities, industrial machines, medical devices, etc. It is.

DESCRIPTION OF SYMBOLS 11 ... Core material, 21 ... Casing, 22 ... Magnetic powder, 23 ... Mixture of magnetic powder and inorganic binder, 31 ... Permanent magnet.

Claims (9)

  A method of manufacturing a magnetic member, comprising: filling a mold or casing with a powdery magnetic substance; and injecting a binder into the mold or casing.   The method for producing a magnetic member according to claim 1, wherein the binder has a viscosity of 250 mPa or less.   The method for manufacturing a magnetic member according to claim 1, wherein a filling rate of the magnetic substance in the mold or the casing is 90 to 98%.   The method for manufacturing a magnetic member according to claim 1, wherein the powdery magnetic substance has an average particle size of 200 mesh or less.   The method for manufacturing a magnetic member according to claim 1, wherein the mold or casing is made of at least one material selected from the group consisting of wood, resin, and soft magnetic materials such as iron tubes and iron plates.   A magnetic member manufactured using the method for manufacturing a magnetic member according to claim 1.   The magnetic member according to claim 6, wherein the magnetic member is a core material of an electromagnetic coil.   The magnetic member according to claim 7, wherein the core material is a core material for a bobbinless coil.   The magnetic member according to claim 6, wherein the magnetic member is a permanent magnet.

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