JPH0777177B2 - Simultaneous multi-pole magnetized injection molding die and simultaneous multi-pole magnetized molding method using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is to combine powder magnetic materials such as ferrite or rare earth magnetic materials with rubber or plastic to integrally mold them, and at the same time, to surround a plurality of them to form a plurality of magnetic materials. The present invention relates to a molding die for manufacturing a multipole magnet having magnetic poles, and a simultaneous multipole magnetizing molding method using the molding die.

[Conventional technology]

Conventionally, a so-called rubber or plastic multipolar magnet containing a powdery magnetic material has been manufactured by a method of magnetizing after molding. Further, Japanese Patent Application Laid-Open No. 61-125009 proposes a simultaneous magnetizing molding method in which a permanent magnet is arranged around a molded product during molding. However, this method has limitations on the permanent magnets and the magnetizing current that can be used, and it is difficult to sufficiently magnetize a magnet material having a high energy product.

On the other hand, the inventors of the present invention, in JP-A-60-107809, insert a magnetized material into a plurality of surrounding bodies made of a metal having a high magnetic permeability such as soft iron and magnetize the material, thereby making it possible to obtain a desired magnetic field at once. A technique for manufacturing a multi-pole magnet having magnetic poles around the entire circumference has been disclosed.

In general, many high-strength cement hardened bodies are known in the field of civil engineering and construction. The present inventor has proposed, in Japanese Patent Application No. 61-14831, a plastic injection molding mold using an ultra-dense cement composed of a hardened material containing cement, ultra-fine powder and a high-performance water reducing agent.

[Problems to be solved by the invention]

Magnetizing at the same time as molding a rubber or plastic magnet is a method of manufacturing magnets suitable for mass production by eliminating the trouble of magnetizing later, but the mold used for injection molding usually has a high magnetic permeability. Since it is made of metal, the magnetic flux applied for magnetization flows into the mold, and simultaneous multipole magnetization was impossible unless a special method was adopted.

INDUSTRIAL APPLICABILITY The present invention is capable of magnetizing a rubber or plastic magnet at the same time as molding, and particularly, a simultaneous multipolar magnetizing injection molding die for simultaneously manufacturing a multipolar magnet and a simultaneous multipolar magnetizing injection using the same. An object is to provide a molding method.

[Means for solving problems]

The present invention is a rubber or plastic injection-molding die composed of a non-magnetic material and a highly magnetically permeable material, wherein the outer periphery of the cavity is made of a metal having a higher magnetic permeability than the magnetized material to be molded as the highly magnetically permeable material. A sleeve is locally provided in a radial, annular or cap shape surrounding the cavity, and a high-strength cement hardened material is used as the magnetic material, and further, in the yoke installed on the outer periphery or both ends of the mold. An exciting coil is provided, and a current is applied to the exciting coil during the cooling period of the molded product to magnetize the molded product at the same time.

The non-magnetic material according to the present invention is required to have a lower magnetic permeability than the material to be magnetized, and to be a material that can withstand heat and mechanical stress during molding. As a material suitable for this requirement, there is a material containing a high-strength cement hardened material as a main component. High strength cement hardened material has a compressive strength of 600 Kgf / c
m ² or more, preferably 1,000 Kgf / cm ² or more,
For example, Portland cement, a combination of anhydrous gypsum-based admixture and water-reducing agent, so-called MDF formed by kneading alumina cement and poval with a low water-powder ratio and high shear force.
Examples include cement, or ultra-compact cement having a low water cement ratio by combining cement, ultrafine powder, aggregate and a high-performance water reducing agent.

In consideration of transferability or moldability, ultra-dense cement is particularly preferable. Ultra-dense cement is a composition containing ultra-fine powder, cement, and a high-performance water reducing agent as main components. Here, the ultrafine powder is a powder having a particle size that is about 2 orders of magnitude smaller than that of cement and a particle size of about 1 μ or less, and there are no particular restrictions on the components, but those that are readily soluble in water are not suitable. . In the present invention, silicon, silicon-containing alloys and silica dust (silica fume) by-produced when producing zirconia and siliceous dust are particularly suitable, fly ash, calcium carbonate, silica gel, opalaceous silica, titanium oxide,
Aluminum oxide, etc. can also be used.

As the cement, hydraulic cement such as Plutoland cement, alumina cement or the like is used, and the average particle diameter is usually 10 to 30 μm, and inert particles having the same particle diameter may be combined.

The high-performance water reducing agent may be a surfactant having a large dispersive power without causing excessive delay of setting or excessive air entrainment even when added in a large amount to cement, and a salt of melamine sulfonic acid formaldehyde condensate or naphthalene sulfonic acid. Formaldehyde condensate salts, high molecular weight lignin sulfonic acid and the like can be used. When using alumina cement, it is also possible to use phosphates, organic acid salts and the like.

Usually, aggregates and fibers having a larger particle size are used in combination. At this time, it is necessary to select a material that does not adversely affect the magnetic permeability, for example, river sand, river gravel, crushed sand, crushed stone, granite, various ceramics, white baux, heavy shale shale, etc. Examples of the fibers include inorganic fibers such as glass fibers and alumina fibers, heat resistant organic fibers such as Kevlar, and the like.

The ultra-dense cement of the present invention, water in the kneading, because the cement ratio can be extremely small, the porosity after curing is about 1/2 to 1/3 of the conventional cement hardened body, excellent strength Have.

In the rubber or plastic magnet manufactured in the present invention, rubber, plastic material such as silicone, nylon, polyester or the like, and magnetic substance powder such as ferrite, magnetic metal powder or rare earth magnetic material are used.

In the manufacture of the multi-pole magnet, it is important that the magnetized material is locally brought into close contact with or close to the sleeve at the magnetization stage. The sleeve is made of a metal having a higher magnetic permeability than that of the material to be magnetized, preferably soft magnetic material such as soft iron, permalloy or permender, and it is arranged around the cavity according to the shape and magnetization pattern of the product to be molded and is a non-magnetic material. Together with the mold. The sleeve is annular when it is in the middle of the magnetized material, but it is cap-shaped when it is provided at the tip. Alternatively, they may be arranged radially depending on the purpose. However, in order to form a multi-pole magnet, it is essential that a non-magnetic material intervenes in at least part of the magnetic path through which the exciting magnetic flux near the magnetized material passes. A magnetic pole is formed near the interface with.

In order to magnetize the molded plastic magnet, it is better to cool it slightly after it has been cooled than at high temperature immediately after injection, and the temperature is 200 ° C or lower. The exciting coil is provided on the opposing metal holder by a known means such as bolting or fitting, at an inner portion of the guide roller for opening and closing the fixed pair of molds.
Alternatively, as the outer iron type, the opposing metal holder may be used as a yoke material, and the magnetic path and the exciting coil may be installed in the extension portion thereof.

In addition, a known method in which a direct current or a pulsating current is applied to form a magnetic field around the outer periphery of the cylinder portion for melting the material to be molded or around the mold to form oriented magnetic domains in the molding material in advance is also used. Good.

[Action]

According to the present invention, since the non-magnetic material is used as a part of the constituent material for the injection molding die, the conventional defect that the exciting magnetic flux flows into the die and cannot be magnetized in multiple poles is solved, and it is magnetized at the same time as molding. It has become possible. Further, since the sleeve necessary for manufacturing the multi-pole magnet is arranged at the position surrounding the cavity, it is not necessary to detach the sleeve from the magnetized material in manufacturing the multi-pole magnet. At this time, the metal holder that fixes the mold acts as a yoke.

Upon excitation, the applied excitation magnetic flux enters the molded body of the magnetized material from the holder that acts as a yoke, exits the molded body at the location where the sleeve is provided, passes through the sleeve with a higher magnetic permeability, and In the non-existing part, it passes through the molded body of the material to be magnetized again and finally forms a magnetic path to the other holder. At this time, magnetic poles are formed at the portions of the magnetized material where the magnetic flux comes in and out.

〔Example〕

FIG. 1 is a cross-sectional view showing a state in which the injection of the plastic magnet material into the mold is finished and a current is passed through the exciting coil to be magnetized. Reference numeral 1 is a supply port for supplying the molten molding material 2. As the molding material 2, a mixture of 6-nylon and ferrite powder containing 85% or more of ferrite was used. Reference numeral 3 is a fixed holder, and 3'is a movable holder, and the guide rod 4 is slidably passed through the movable holder 3 '. 5 is a mold composed of ultra-dense cement 6 and soft iron 7 having the function of a sleeve.
It is firmly joined by fitting, fusion bonding, brazing or adhesive. The mold 5 is divided into two by the central dividing section 8. The mold 5 is fixed to the fixed holder 3 by a known means, the mold 5'is fixed to the movable holder 3 ', and the non-magnetic material 9
The exciting coil 10 is fixed via. The non-magnetic material 9 is provided so that the exciting coil 10 and the holder 3 do not come into contact with each other. The other end of the exciting coil 10 is a free end. Reference numeral 11 is a power source, and 12 is a switch. In FIG. 1, the moment of magnetization is shown.

Although the exciting coil is fixed to the movable holder in this embodiment, it may be fixed to the fixed holder.

The plastic magnet (magnetized molded body) 13 thus obtained was, as shown in FIG. 2, a multi-pole magnet having 5 pairs of S and N poles alternately arranged on the side surface in an annular shape. In the drawing, the portion indicated by the set of points is the magnetic pole 14.

The present embodiment is one mode showing the constitution of the present invention, and the shape of the cavity, the size, the position, the number of the sleeve, etc. can be appropriately selected depending on the shape of the magnetized molded body, the number and the position of the magnetic poles. it can.

〔effect〕

According to the present invention, a material having a high energy product such as a rare earth magnetic material can be applied with a sufficient exciting current (magnetic flux) to be completely magnetized, and thus a strong and high coercive force can be obtained. It can also be used for simultaneous magnetizing and magnetizing. In addition, the performance as a mold does not need to consider maintaining its magnetic performance, and it depends only on the mechanical shape, so it can be handled in the same way as a general mold, and is suitable for mass production. It can be shaped and magnetized.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a cross-sectional view showing a molding die and a manufacturing process, and FIG. 2 is an explanatory view showing positions of magnetic poles of a manufactured magnet. In the drawings, reference numeral 1 is a supply port, 2 is a molding material, 3 and 3'is a holder, 4 is a guide rod, 5 is a mold, 6 is super-dense cement, 7 is soft iron, 8 is a split portion, and 9 is non-permeable. Material, 10 is an exciting coil,
Reference numeral 11 is a power source, 12 is a switch, 13 is a plastic magnet (molded body to be magnetized), and 14 is a magnetic pole.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B29L 31:34 (72) Inventor Shun Moriyama 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Electric Chemicals Industrial Co., Ltd. (72) Inventor Chiyuki Fujii 1-4-1, Yurakucho, Chiyoda-ku, Tokyo Electric Chemicals Co., Ltd. (56) Reference JP-A-57-170502 (JP, A) JP-A-59 -168620 (JP, A) JP-A-60-186008 (JP, A)

Claims (3)

[Claims] 1. A rubber or plastic injection molding die made of a non-magnetic material and a highly magnetically permeable material, wherein a metal having a higher magnetic permeability than the magnetized material to be molded is used as the highly magnetically permeable material on the outer periphery of the cavity. A multi-pole magnetized injection molding of rubber or plastic magnets, characterized in that a high-strength cement hardened material is used as a non-magnetic material by locally providing a sleeve that surrounds the cavity in a radial, annular or cap shape. Type. 2. A simultaneous multi-pole magnetized injection molding mold for rubber or plastic magnets according to claim 1, wherein the high-strength cement hardened body is an ultra-dense cement. 3. Injection molding of rubber or plastic composed of a non-magnetic material and a high-permeability material made of a high-strength cement hardened material in mixing a magnetic powder and rubber or plastic to mold a rubber or plastic magnet. At the same time, a mold made of metal having a higher magnetic permeability than the magnetic material to be molded is provided as a highly magnetically permeable material locally around the cavity in a radial, annular or cap shape surrounding the cavity. Multi-pole magnetizing Simultaneous multi-pole magnetizing, in which an exciting coil is provided on the outer circumference or both ends of an injection molding die, and a current is applied to the exciting coil during the cooling period of the molded product to magnetize it simultaneously with molding. Molding method.