JPH04273107A - Combined magnetic substance and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an optimum magnetic-circuit characteristic and to lower an iron loss by a method wherein a plurality of materials containing a magnetic material whose electric resistivity is high are combined, a part between the materials is set to a baked state and a magnetic substance having an arbitrary shape is formed. CONSTITUTION:An electromagnetic steel plate, in 0.35mm, whose Si content is at 6.5% is plated with Cu to be in 1mum after that, is plated with Sn to be in 0.2mum. The plated electromagnetic steel plate is stamped to be a final shape. Three plates are stacked, baked and annealed; a combined magnetic substance 5 is made. The stacked plates are baked and annealed in an atmosphere which contains little moisture and which is composed of 5 % of hydrogen and 95 % of nitrogen, at 800 deg.C, for two hours and in a pressurized state of about 30g/cm<2>. Plated parts are set to baked states 13. Thereby, it is possible to easily obtain the magnetic substance which is composed mainly of a magnetic material whose electric resistivity is high, which is in an arbitrary shape and whose mechanical strength is high. Its iron loss is lowered. When the combined magnetic substance 5 is used, an energy efficiency can be improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic material used for yokes of magnets, electromagnets, cores for other applications, etc., and a method for manufacturing the same.

0002

2. Description of the Related Art A motor uses a large number of permanent magnets and electromagnets for magnetic field, and also uses a yoke as a magnetic material to make the field distribution appropriate. O
With the advancement of A equipment and FA equipment, the motors used in these equipment are required to have a structure suited to the purpose of use, and the yokes used are also becoming smaller and having complex shapes. Furthermore, in order to achieve high energy efficiency, it is increasingly necessary to reduce the energy consumed within the yoke, that is, the iron loss. Not only in motors but also in other applications, magnetic materials are used in cores and yokes, and are often used in complex shapes, where miniaturization, high energy efficiency, and cost are often issues.

[0003] Complicated processing is required to make magnetic materials small and have arbitrary shapes as yokes and cores. Methods for manufacturing such magnetic materials include the lost wax method and powder metallurgy, but it is difficult to obtain a yoke with optimal magnetic circuit characteristics at low cost. On the other hand, a method for obtaining an arbitrary shape is to use laminated steel plates, but this often requires mechanical strength, which poses a problem.

[0004] For cores, yokes, etc., it is important not only to have arbitrary shapes and miniaturization, but also iron loss for energy efficiency. In the yoke, when there is a change in magnetic flux, eddy currents tend to flow, increasing iron loss. Even in the case of laminated magnetic steel sheets, if magnetic flux changes occur perpendicularly to the surface of the magnetic steel sheets, in-plane eddy currents flow and iron loss increases.

[0005] One way to relatively easily provide a magnetic material with an arbitrary shape at low cost is to laminate plate-shaped magnetic materials such as plated silicon steel plates and bake them to obtain an arbitrary shape. However, the yoke obtained by this method aims to reduce the electrical resistance of the yoke, and has a problem in energy efficiency, that is, iron loss. As described above, conventional magnetic materials have many problems in terms of shape, magnetic circuit characteristics, cost, and core loss, and are not sufficient.

[0006]

[Problems to be Solved by the Invention] The present invention solves the problems of the prior art described above, and makes a magnetic material of arbitrary shape.
The purpose of this work is to provide an inexpensive magnetic material that provides optimal magnetic circuit characteristics, low core loss, and a method for producing the same.

[0007]

[Means for Solving the Problems] The gist of the present invention is that the material is made by combining a plurality of materials including a magnetic material with high electrical resistivity, which is plated on all or part of the material. A combination magnetic material which is a molded body and is characterized by a burn-in state between the materials, and a magnetic material having high electrical resistivity in which all or part of the material is plated. A combination magnetic body characterized by combining a plurality of materials including the above to form a molded body, and then annealing the molded body under pressure, preferably in a reducing atmosphere, to create a burned state between the materials. This is a manufacturing method.

The present invention will be explained in detail below. first,
The magnetic materials with high electrical resistivity of the present invention include those containing Si, Al, and other elements, such as electromagnetic steel sheets and electromagnetic soft iron, such as electromagnetic steel sheets and electromagnetic soft iron with a Si content of 0.5% or more. Or, if it is possible to apply this invention, it is possible to use other magnetic materials that can obtain the necessary electrical resistivity, and the shape can be any shape, including plate-like, linear, and granular ones. can be used, or a combination of these can be used. If other materials are used in part, any material may be used as long as the present invention is applicable and the required electrical resistance is maintained, including not only magnetic materials but also non-magnetic materials. It does not matter that the material may be included in a part, and the shape does not matter.

Copper, aluminum, nickel, tin, zinc, and alloys thereof can be used as materials to be plated on the surface of materials such as magnetic materials. The plating thickness must be small enough to maintain high electrical resistance between the combined materials, and also promote seizure between the materials to ensure sufficient mechanical strength of the material combination molded product. The thickness must be as required. The type of material to be plated on the surface of the material must be determined depending on the difficulty of plating and the required magnetic circuit characteristics. When a magnetic flux is caused to flow in a direction perpendicular to the length direction of the magnetic material, it is preferable to select a material with excellent magnetization properties, such as nickel, as the plating material. On the other hand, if the magnetic flux is to flow in the plane of the magnetic material or in the linear direction, it is sufficient to plate the material with a non-magnetic material. It is not necessary to apply this plating to all materials. As long as a burned-in state can be obtained and the necessary mechanical strength can be obtained, it may be a part of the material, and it may be a part of the surface or one side of the material rather than the entire surface of the material. Furthermore, one or more types of plating materials may be combined.

When combining magnetic materials, the shape and arrangement of the magnetic materials can be adjusted by arranging them so that their axes of easy magnetization are aligned as much as possible along the flow of magnetic flux used, or by utilizing shape magnetic anisotropy. It is good to use. For example, if the axis of easy magnetization of a unidirectional electrical steel sheet is aligned with the rolling direction of the material, it should be arranged so that the rolling direction is aligned as much as possible along the magnetic flux flow to be used, or It is best to match the plate surface of the plate-shaped magnetic material and the line direction of the linear magnetic material.

[0011] After the magnetic materials and the like are combined, annealing is performed to cause the materials to stick together. What is the baking of the present invention?
These include melting of plating materials at high temperatures, chemical reactions between plating materials, chemical reactions between combined materials and plating materials, and adhesion phenomena at high temperatures. In order to sufficiently bake between materials and create a magnetic material with high mechanical strength, the surface of the magnetic material, etc. must be clean, free from dirt from oil or foreign matter, and have a small surface roughness. is necessary. To clean the surface of magnetic materials, etc., pickling or oil washing may be performed.

[0012] In order to combine materials such as magnetic materials and form them into a predetermined shape, the materials are cut or punched and combined, but if necessary, molding may be performed. This molding process is effective in increasing the contact area and increasing the space factor of the resulting magnetic material in order to sufficiently bake the materials together after combination molding. In order to obtain a magnetic material with a predetermined shape, it is necessary to consider the shape of the material to be cut or punched and its combination, and annealing is performed to cause seizure after the combination molding, and then the final shape of the magnetic material is determined. In obtaining this, it is also necessary to take into account thermal strain due to the temperature difference between annealing and the seizure process.

[0013] Annealing releases the distortion of the molded composite body of magnetic materials, etc., and also causes seizure between the materials. It must also be carried out at a temperature and time necessary to provide the required mechanical strength in a given shape. In this annealing process, in order to maintain the predetermined shape of the molded combination of magnetic materials, etc. and to promote seizure between the materials, annealing is necessary for the molded combination of magnetic materials, etc. must be carried out under pressure. However, if the same effect can be obtained by the weight of the molded material combination, the pressurizing means can be omitted. Also, it is preferable that the annealing is performed under a reducing atmosphere.

[0014] The surface of materials such as magnetic materials is often covered with an oxide film, and if left as is, burn-in may be difficult to occur. When annealing is performed in a reducing atmosphere, the surface of the material is reduced, making it easier for seizure to occur between the materials. A process in which annealing is performed under a reducing atmosphere is effective.

[0015]

[Example] Fig. 1 shows 0.3 with a Si content of 6.5%.
A 5 mm electromagnetic steel sheet 1 is first coated with Cu plating 2 of 1 μm, and then coated with Sn plating 3 of 0.2 μm. Figure 2
1 is a combination magnetic body 5 made by punching the plated electromagnetic steel sheets 4 shown in FIG. 1 into a final shape, stacking three sheets, and performing baking annealing according to the present invention. Baking annealing is performed in an atmosphere of 5% hydrogen and 95% nitrogen that contains almost no moisture.
The plating was carried out at 800° C. for 2 hours under a pressure of about 30 g/cm 2 , and the plated portion reached a baked-in state 13.

FIG. 3 shows a rotor of a brushless motor in which the combined magnetic material 5 of the present invention is used in a magnet yoke 6 and an armature core 7. Reference numerals 8 and 6 are permanent magnets and their yokes constituting the rotor, and 9 and 7 are armature coils and their cores constituting the stator. Further, 10 is a motor shaft passing through these, 11 is a bearing, and 12 is a motor support stand. Due to the armature current, the 6.5%Si which is the yoke and core
Magnetic flux changes occur perpendicularly to the plate surface of the non-oriented electrical steel sheet, and eddy currents flow in the plane, but the eddy current is suppressed because the electrical resistance of the 6.5% Si non-oriented electrical steel sheet is high. is,
Iron loss is reduced, resulting in a highly efficient motor.

[0017]

[Effects of the Invention] The combined magnetic body of the present invention is mainly composed of magnetic materials with high electrical resistivity, and can be relatively easily obtained in any shape and high mechanical strength. Therefore, iron loss is reduced, and when the combined magnetic material of the present invention is used, the energy efficiency of the device can be improved. In particular, when magnetic flux passes in the stacking direction of the plates, iron loss can be reduced by using a material with a high Si content. In addition, it has high mechanical strength that cannot be obtained by laminating magnetic steel sheets, so it is suitable for cases where strength is required or where vibration is a problem.

The method of the present invention uses low-cost processing such as plating, punching, molding, and annealing, and other methods,
For example, it is lower cost than the lost wax method or lathe processing, and by using a thin plate that can be processed even if it is relatively hard and difficult to process, you can easily create magnetic materials such as cores and yokes of your choice. It will be done.

Furthermore, the combined magnetic material of the present invention not only has high electrical resistivity, arbitrary shape, and high mechanical strength, but also exhibits excellent three-dimensional magnetic circuit characteristics. This is because materials such as magnetic steel sheets with excellent magnetic properties can be used, and in the case of a combination of magnetic materials, the easy magnetization axis and shape anisotropy of the materials, or the selection of plating materials can cause the joint to This is because the magnetic flux flow can be optimized by controlling the magnetic properties of the material and making it three-dimensional by molding. The magnetic materials constituting the combined magnetic body of the present invention are suitable for processing such as plating, punching, and annealing in large quantities, and the combined magnetic body of the present invention can be mass-produced.

[Brief explanation of the drawing]

FIG. 1 shows a plated electrical steel sheet made of a combination magnetic material.

FIG. 2 shows a combination of magnetic materials used in the yoke and core of a motor.

FIG. 3 shows a brushless motor using a combination of magnetic materials.

[Explanation of symbols]

1 Electromagnetic steel sheet of 0.35 mm with Si content of 6.5% 2 Cu plating 3 Sn plating 4 Plated electromagnetic steel sheet 5 shown in FIG. 1 Combination magnetic body 6 Magnet yoke 7 Armature core 8 Permanent magnet 9 Armature coil 10 Motor shaft 11 Bearing 12 Base that supports the motor 13 Seizure part

Claims (6)

[Claims] [Claim 1] A molded body made by combining multiple materials including a magnetic material with high electrical resistivity, which is plated on all or part of the material, and where there is a burn-in state between the materials. A combination magnetic material characterized by: 2. The combination magnetic body according to claim 1, wherein the molded body is entirely composed of a magnetic material having high electrical resistivity. 3. The magnetic material with high electrical resistivity is Si
The combination magnetic material according to claim 1 or 2, which contains 0.5% or more of. 4. The combined magnetism according to any one of claims 1 to 3, wherein the compact is configured such that the axis of easy magnetization of a magnetic material having high electrical resistivity is oriented along a predetermined magnetic flux flow. body. 5. After forming a molded body by combining a plurality of materials including a magnetic material with high electrical resistivity, in which all or part of the materials are plated, the molded body is pressed under a pressurized state. 1. A method for producing a combination magnetic material, characterized by annealing the material to create a stuck state between the materials. [Claim 6] Annealing of the molded body under pressure comprises:
The method for producing a combination magnetic material according to claim 5, wherein the method is carried out under a reducing atmosphere.