JPS58219705A - Anisotropic ring polymer magnet and apparatus for manufacturing the same - Google Patents

Abstract

PURPOSE:To obtain an anisotropic ring polymer magnet which is small in size and lightweight as well as excellent in magnetic properties and make it possible to select the number of magnetized poles so as to obtain a multiplicity of poles, by radially orientating easily magnetizable axes. CONSTITUTION:An anisotropic ring polymer magnet 1 is made of a material obtained by kneading a magnetic material 2 with magnetic anisotropy and a polymer material 3. The easily magnetizable axes of the magnetic material 2 are radially orientated with the circle center as a starting point. An apparatus for manufacturing the magnet 1 has an outside member composed of a non-magnetic die 10, a material inlet outer wall die 11 and an outside die 12, and a central die 9 of a ferromagnetic material. A kneaded material charging space 13 is defined between the outside member and the central die 9. An electromagnetic coil 6 is wound on the intermediate part of the central die 9 through the outside member, to constitute a closed magnetic circuit by the outer wall die 11, a ferromagnetic block 14, the outside die 12 and the central die 9. A radial magnetic field is applied to the kneaded material while the material is transferred from an inlet 7 to a molded article outlet 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anisotropic ring-shaped polymer magnet in which the axis of easy magnetization is radially oriented during an extrusion process, and an apparatus for manufacturing the magnet.

Polymer magnets are made by mixing and molding magnetic powder such as ferrite with polymer materials such as rubber or synthetic resin.
Compared to hard magnets such as sintered magnets, they have superior elasticity, flexibility, workability, and dimensional stability, so in recent years they have been used in toys, office supplies, mechanical devices, electrical and electronic equipment, etc. in various shapes. has become widely used. However, although polymer magnets have various advantages as mentioned above, they also have some disadvantages due to their manufacturing method.
Since it contains about 0 to 20% by weight of a non-magnetic material in its composition, it has lower magnetism than the above-mentioned sintered magnet, and has the disadvantage that the shape becomes larger in order to have the same magnetic properties. Therefore, motors that require small size and light weight,
In ring-shaped magnets used in rotating equipment such as generators, sintered magnets such as 7-piece light magnets are currently mainly used. Usually, polymer magnets obtained by molding and magnetizing a cross-wire material of a magnetic material and a polymer material have low magnetism because they are magnetically isotropic as they are. It is necessary to impart magnetic anisotropy through a chemical treatment. For example, in the case of sheet-shaped polymer magnets, anisotropy is imparted by applying mechanical shear stress and rolling. This is because ferrite powder, which is used as a magnetic material for polymer magnets, has an axis of easy magnetization in the C-axis direction of a hexagonal crystal structure, and develops on a hexagonal flat plate in a direction perpendicular to this C-axis. It has a magnetic brambite-type crystal structure, and by applying mechanical shear stress and rolling, the crystals on the flat plate overlap and align their directions, and the randomly oriented easy axis of magnetization aligns with the surface of the sheet. This is because it is oriented in the vertical direction. 5 However, this method is limited to cases where the shape of the polymer magnet is sheet-like, and it is difficult to apply it to ring-shaped polymer magnets. It is true. Therefore, as a countermeasure against this problem, in the conventional extrusion molding process, as shown in FIG. An anisotropic ring-shaped polymer magnet 1 has been proposed in which the axis of easy magnetization is oriented in the direction of the applied magnetic field. However, the magnetic anisotropy of the anisotropic ring-shaped polymer magnet 1 is arranged in one radial direction. The magnetic properties differ depending on the direction. Therefore, it is possible to obtain anisotropic magnetic properties of 60X-80% only when the number of magnetized poles is two, but in other cases, the magnetic flux at the pole of magnetization becomes unsuitable. If used in rotating equipment, it will cause an extreme decrease in torque.

The present invention was devised in view of the above-mentioned points, and is small, lightweight, and has excellent magnetic properties, and the number of magnetized poles can be freely selected, even multi-directional poles, making it suitable for various fields including rotating equipment. It is an object of the present invention to provide a suitable anisotropic ring-shaped polymer magnet and manufacturing apparatus.

In order to achieve the above object, the anisotropic ring-shaped polymer magnet of the present invention is made of a cross-wire material of a magnetic material having magnetic anisotropy and a polymer material. It has a structure in which the easy axis is oriented radially, and furthermore, as a manufacturing apparatus for the above-mentioned anisotropic ring-shaped polymer magnet, a cross-wire material having a ring-shaped cross section is inserted between the outer member and the central die made of a ferromagnetic material. A filling space is formed, and an electromagnetic coil is wound around the middle part of the central die via the outer member.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a cross-sectional view of an anisotropic ring-shaped polymer magnet according to an embodiment of the present invention. In the figure, an anisotropic ring-shaped polymer magnet 1 has a magnetic material 2 and a polymer material 5 A cross-wire material of the magnetic material 2 is formed into a ring shape, and the axis of easy magnetization of the magnetic material 2 is oriented radially from the center of the circle.

In the present invention, as a method for radially orienting the axis of easy magnetization of the above-mentioned ring-shaped polymer magnet, the cross-wire material of the magnetic material and the polymer material is radially oriented during the extrusion molding process from a molten state to a solidified state. Molding is performed while applying a magnetic field, and an embodiment of the manufacturing apparatus is shown in FIGS. 6 and 4. The anisotropic ring-shaped polymer magnet manufacturing apparatus 4 shown in this embodiment has an extrusion mold 5 equipped with an electromagnetic coil 6 for generating a magnetic field. That is, the interfering material injection part 7 made of gold 5
The magnetic core is a ferromagnetic central die 9 with a circular cross section of the mold 5 component extending from the molded product outlet 8.
Cross line material injection part 7 side of central die 9 and molded product outlet 8
Similarly, an electromagnetic coil 6 is wound around the middle part except for the sides through the non-magnetic die 101 of the mold 5 component. Further, the non-magnetic die 10 is composed of the material injection part outer wall die 11 of the mold 5 component adjacent to the front end thereof, and the outer die 12 of the mold 5 component adjacent to the rear end of the non-magnetic dice 10. A cross-conducting material filling space 16 having a ring-shaped cross section is formed between the outer member to be filled and the central die 9, and this space 16 is filled with a cross-conducting material in the direction from the cross-conducting material injection part 7 toward the molded product outlet 8, that is, the cross-conducting material moves. The thickness of the material is made to gradually become thinner along the direction. The crosstalk material injection part outer wall die 11 and the outer die 12 are formed of a ferromagnetic material, and are combined with the ferromagnetic block 14 and the center die 9 arranged on both end surfaces and the outer surface of the electromagnetic coil 6. It forms a closed magnetic circuit. In addition, the material filling space 16 of the magnetic circuit part from the center die 9 to the crosstalk material injection part outer wall die 11 and the magnetic circuit part from the outer die 12 to the center die 9 is formed in a direction parallel to the axial direction of the ring shape. It is formed. It should be noted that the ferromagnetic block 1 located around the electromagnetic coil 6
4. Although the shape of the outer die 12 and the material injection part outer wall die 11 is circular in this embodiment, it is not limited to this shape. In the anisotropic ring-shaped polymer magnet manufacturing apparatus 4 configured as described above, when an excitation current is applied to the electromagnetic coil 6, a magnetic flux is induced in the ferromagnetic central die 9, and the dirt is shown by the arrow in the figure. As shown, the center die 9 → the crosstalk material injection part outer wall die 11 − the ferromagnetic blocks 14 disposed on both end surfaces and the outer surface of the electromagnetic coil 6 →
It flows from the outer die 12 to the center die 9, is injected from the injection part 7, passes through the crosstalk material filling space 16, and reaches the molded product outlet 8.
The crosstalk material of the magnetic material 2 and the polymer material 3 in a molten state is connected to the magnetic circuit from the center die 9 to the injection part outer wall die 11 and the magnetic circuit from the outer die 12 to the center die. As it passes, a radial magnetic field is applied twice.

Furthermore, the magnetic flux in the two magnetic circuits is transferred to the ring-shaped material filling space 1 due to the adjacent non-magnetic block 10.
3, and as described in the configuration of the device 4, the ring-shaped material filling space 13 in this part is parallel to the axial direction, so the radial electric field is directed in the thickness direction of the crosstalk material. It will act perpendicular to. Therefore, the anisotropic ring-shaped polymer magnet 1 formed by the apparatus 4 of this embodiment
is radial, and its axis of easy magnetization is oriented perpendicular to its thickness direction.

As explained above, the anisotropic ring-shaped polymer magnet of the present invention has the axis of easy magnetization radially oriented, so it exhibits high magnetic properties even when miniaturized, and is uniform in all parts. Because it has magnetic properties, it has ideal characteristics for use in uniformly rotating equipment that can have multiple magnetized poles, and is also suitable for use in magnetic couplings such as clutches, sensors, etc. It can be suitably used in the field. Further, the anisotropic ring-shaped polymer magnet manufacturing device of the present invention forms a cross-wire material filling space having a ring-shaped cross section between the outer member and a central die made of a ferromagnetic material, and In addition, since the electromagnetic coil is wound through the outer member, it is possible to apply a radial magnetic field twice to the crosstalk material moving through the material filling space, so that the axis of easy magnetization of the ring magnet can be radially aligned. In addition, the inner part of the outer member around which the electromagnetic coil is wound is made of a non-magnetic material, the ferromagnetic parts adjacent to both ends of the inner part, and the ferromagnetic blocks arranged on both end surfaces and the outer surface of the electromagnetic coil. Since a closed magnetic circuit is formed by the magnetic coil and the central die, the magnetic flux induced in the central die by energization with the electromagnetic coil can be fully applied to the crosstalk material. Furthermore, if the material filling space in the magnetic circuit from the central die to the outer member is formed in a direction parallel to the axial direction of the ring shape, the radial magnetic field will act perpendicularly to the thickness direction of the crosstalk material. Therefore, it is possible to manufacture an anisotropic ring-shaped polymer magnet in which the axis of easy magnetization is oriented radially and perpendicularly to the thickness direction.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional anisotropic ring-shaped polymer magnet, Fig. 2 is a cross-sectional view of an anisotropic ring-flat type combined magnet according to an embodiment of the present invention, and Fig. 6 is a cross-sectional view of a conventional anisotropic ring-shaped polymer magnet. FIG. 4 is a cross-sectional view showing one embodiment of an apparatus for producing a oriented ring-shaped polymer magnet, and FIG. 4 is a partially cutaway perspective view of FIG. 6. 1... Anisotropic ring-shaped polymer magnet 2... Magnetic material 6... Polymer material 4... Anisotropic ring-shaped polymer magnet manufacturing apparatus 5... Molding mold 6...・
Electromagnetic coil 9...Central chair 10...Non-magnetic die 11...Material injection section outer wall die 12
...Outer die 16...Material filling space □ 1゛4...Ferromagnetic block Patent applicant Magex Co., Ltd. Agent Patent attorney 1) Toshibe Bebe No. 31 Yo: x1 drawing 2nd drawing

Claims (1)

[Claims] 1) Anisotropic ring shape (circular or rectangular shape) made of a cross-wire material of a magnetic material having magnetic anisotropy and a polymer material
An anisotropic ring-shaped polymer magnet characterized in that the axis of easy magnetization is radially oriented in the polymer magnet. 2) In an anisotropic ring-shaped polymer magnet manufacturing apparatus in which a cross-wire material of a magnetic material having magnetic anisotropy and a polymeric material is molded while applying a magnetic field during the extrusion molding process, the outer member and the ferromagnetic From the body, a ring-shaped cross-sectional (circular or rectangular) cross-wire material filling space is formed between the five central dies, and an electromagnetic coil is wound around the middle part of the central die via the outer member. An anisotropic ring-shaped polymer magnet manufacturing device characterized by: 6) The inner part of the electromagnetic coil is made of a non-magnetic material, and the parts adjacent to it on both sides are made of a ferromagnetic material, and ferromagnetic blocks are arranged on both end surfaces and the outer surface of the electromagnetic coil, and a central die, The anisotropic ring-shaped polymer magnet manufacturing apparatus according to claim 2, characterized in that the ferromagnetic portion of the outer member and the ferromagnetic block constitute a closed magnetic circuit. 4) From the central die An anisotropic ring according to claim 6, characterized in that the crosstalk material filling space in the magnetic circuit extending over the outer member is formed in a direction parallel to the axial direction of the ring shape (circular or square shape). Polymer magnet manufacturing equipment.