JPH04320010A - Fabrication of combined magnetic substance - Google Patents

Abstract

PURPOSE:To provide a method of fabrication of a combined magnetic substance simply in a short time by combining and forming a magnetic material including a plated layer using the same partly or wholly, and thereafter bringing the materials into a baked state thereamong. CONSTITUTION:In a method of fabrication of a combined magnetic substance which is formed by combining magnetic materials each including a plated layer into a molded product using the same material partly or wholly, and thereafter bringing those materials into a baked state thereamong, direct baking is carried out under pressurized molding in a reduction atmosphere through a direct heating method. The direct heating method includes a direct power conduction heating method and an induction heating method, etc., and in the power conduction heating method pressurized molding can be achieved using an associated electrode.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a composite magnetic material used for materials such as yokes or shields used in motors, generators, and other applications.

0002

2. Description of the Related Art In small motors, not only many magnets are used for the field, but also yokes are used to make the field distribution appropriate. Recently, with the advancement of OA equipment and FA equipment, the small motors used in these equipment are required to have a structure suitable for the purpose of use, and the yokes used are also becoming smaller and more complicated. There is a growing demand for shapes. Even if divided, HD
In motors for driving magnetic heads such as D and FDD and actuators for optical pickups such as CD, miniaturization of the yoke and a yoke shape suitable for an optimum magnetic circuit have become important issues. Furthermore, controllability is important for these actuators, and low electrical resistance is one of the properties required of the yoke.

[0003] In order to make the yoke smaller and to form it into an arbitrary shape, complicated machining is required. Methods for manufacturing such a yoke 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, there is a method to obtain an arbitrary shape by using laminated steel plates, but this method requires mechanical strength as the field yoke of the actuator, which poses a problem.

On the other hand, magnetic materials used for magnetic shields and the like are often combined to form an optimal magnetic circuit depending on the magnetic field strength and frequency. In this case, there are problems such as complexity in handling and fixing, and maintenance of structural strength. Yokes, etc. with excellent magnetic circuit characteristics and low electrical resistance can be provided relatively easily at low cost by combining magnetic materials such as conductive plated silicon steel sheets and baking them into any desired material. How to obtain the shape (Patent application No. 1-2
No. 30994), but in actual baking annealing, there are problems such as the process of charging into an annealing furnace takes time. Therefore, it would be very efficient if this baking annealing could be done easily and in a short time.

[0005]

[Problems to be Solved by the Invention] The present invention provides a combined magnetic body that is produced by using all or part of magnetic materials having a plating layer, combining them into a formed body, and then bringing the materials into a baking state. This was done with the aim of providing a manufacturing method that can be easily performed in a short period of time.

[0006]

[Means for Solving the Problems] The gist of the present invention is to
It is as follows. (1) In the method of manufacturing a combination magnetic material, which uses all or part of magnetic materials having a plating layer, combines them into a formed body, and then creates a state of burning between the materials, burning is achieved by direct heating. A method for producing a combination magnetic material characterized by causing the following.

(2) The method for producing a combined magnetic material according to item 1 above, characterized in that the method is carried out under a reducing atmosphere. (3) The method for producing a combined magnetic material according to item 1 or 2 above, characterized in that the method is carried out under pressure molding. (4) Paragraph 1, 2 or 3 using direct current heating method
The method for manufacturing the combination magnetic material described above.

(5) The method for producing a combined magnetic material according to item 1 or 2 above, characterized in that pressure molding is carried out using a direct current heating method and with electrodes that are directly energized. (6) A method for producing a combined magnetic material according to item 1, 2 or 3 above, using an induction heating method. The present invention will be explained in detail below.

First, the combined magnetic material of the present invention can be used in yokes used in motors, generators, and other applications, used in shields, or used in cases where other magnetic properties are required. Rather than simply using magnetic materials such as plates or wires, they use a combination of several materials or types of materials. First, as the magnetic material used in the combined magnetic body of the present invention, any magnetic material such as electromagnetic iron plate, electromagnetic soft iron, ordinary steel, iron-nickel alloy, iron-cobalt alloy, etc. can be used in the form of a plate. can. Furthermore, the number of types of magnetic materials is not limited to one type, but a combination of two or more types may be used, and the shapes of the magnetic materials may also be combined with two or more types.

[0010] When plating the surface of these magnetic materials, the materials forming the plating layer include, for example, copper, tin,
Examples include zinc, aluminum, nickel, etc. and alloys thereof. Burning is caused by baking annealing performed after plating these materials. The selection of these plating materials needs to be determined depending on the difficulty of plating, required magnetic circuit characteristics, etc. When a magnetic flux is caused to flow in a direction perpendicular to the surface of the magnetic material, it is preferable to select a material with excellent magnetization properties, such as nickel, as the plating material. Conversely, if the magnetic flux is to flow only within the plate surface of the magnetic material, it is sufficient to plate the plate with a non-magnetic plating material. The thickness of the plating layer applied to the surface of the material needs to be a thickness necessary for baking, and is determined by the characteristics required of the layer formed by baking annealing. For example, if conductivity is required, it is necessary to use a conductive material as the plating material and the required thickness; conversely, if non-conductivity is required, it is possible to If so, a plating material with low conductivity is used, but if a conductive plating material must be used, it is necessary to make it as thin as possible. If magnetic flux is to flow only in the plane of the magnetic material, the layer formed after the plating layer is baked and annealed must be non-magnetic and have a thickness equal to or greater than the required thickness. It must also have a thickness necessary to promote sticking between the materials and to ensure sufficient mechanical strength of the magnetic material combination formed body. The plating applied to the surface of the magnetic material does not need to be plated on both sides, and may be applied to one side or only partially, as long as it can be burnt and has the required mechanical strength.

[0011] It is not necessary to apply this plating to all the magnetic materials, and it is sufficient to apply the plating to each laminated sheet, and the other half may be made of non-plated material. In addition, the plating materials that are stacked and in contact with each other may be different from each other; for example, it is effective to plate one side with copper and the other with tin or zinc, or to plate one side with copper and the other with copper plating and then tin. It may also be galvanized. In this way, when applying two or more types of plating layers, it is preferable that the different plating layers promote seizure in the subsequent baking annealing. In this case, a magnetic material plated with copper and a magnetic material plated with tin, zinc, or copper, and then plated with tin or zinc may be alternately laminated.

[0012] In this way, the magnetic material whose surface is plated is punched out using a punch or the like, taking into consideration the final shape. In this case, the laminated layers may be joined together by caulking. This caulking is generally performed at the same time as the punching process. However, after punching, etc., joining may be performed by caulking. In this process, it is not only necessary to perform the caulking process for each sheet, but also for two or more sheets, and it is also possible to caulk two or more types of magnetic materials at the same time, or to caulk two or more sheets of magnetic materials with different plating layers on the material surface. The caulking process may be performed for a set.

[0013] Annealing (hereinafter referred to as baking annealing) is performed to cause baking between the magnetic materials due to the plating layer. Before this baking annealing, a process such as molding may be added if necessary. In the present invention, as this baking annealing,
It is characterized by the direct heating method. Direct heating methods include direct energization, induction heating such as high-frequency heating, heating by laser irradiation, heating by light irradiation, etc. Direct energization and induction heating are practical in terms of equipment costs and handling. It is also advantageous and effective to carry out this heating under pressure or in a molded state. Moreover, if a direct energization method is used, pressurization or molding may be performed using directly energized electrodes.

[0014] Baking annealing is a process in which magnetic materials are bonded by dissolving or reacting a plating layer, or by other chemical or mechanical effects. This annealing is preferably performed in a reducing atmosphere.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a state in which an electromagnetic steel sheet 1 without a coating is coated with copper plating 2, and FIG. 2 shows a state in which an electromagnetic steel sheet 1' without a coating is plated with tin. The thickness of the electromagnetic steel plate is 0.
The thickness of the copper plating 2 is 1 μm on both sides of the plate, and the thickness of the tin plating 3 is 0.2 μm on both sides of the plate. FIG. 3 shows a state in which one sheet of each of these sheets, that is, a set of two sheets in total, is burned by direct energization. By using the electrode 5 for direct energization, baking annealing can be performed by applying pressure during energization. Reference numeral 6 denotes an anti-seizure member that prevents the electromagnetic steel plates 1 and 1' to seize on the electrode 5.

[0016]

[Effects of the Invention] The present invention provides a method for manufacturing a combined magnetic material in which magnetic materials having a plating layer are used in whole or in part, combined to form a formed body, and then the materials are made into a burned state. This method provides a manufacturing method that can be easily performed in a short period of time, and is industrially useful because it is more advantageous in terms of equipment and time than conventional methods.

[0017] The present invention does not require an annealing furnace unlike the conventional one, and heats directly at or near the location to be joined, so equipment costs and power costs can be reduced. Direct energization and induction heating only require a power source and electrodes, and can be easily performed anywhere. Direct energization is advantageous because the electrode can be used for pressure forming, making it easier to control the pressure during annealing. , the effect of heat on the electrode can be reduced, which is more advantageous than performing the process under pressure in an annealing furnace. It is possible to create a reducing atmosphere only for the parts that are heated during direct energization, and if it is done in a reducing atmosphere, the yokes, etc. that are to be seized will not oxidize, and are likely to seize. It also protects the electrodes.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a copper-plated electromagnetic steel sheet.

FIG. 2 is a diagram showing an electromagnetic steel sheet plated with tin.

FIG. 3 is a diagram showing a state in which a yoke is burned by the direct energization method, which is the method of the present invention.

[Explanation of symbols] 1. Electrical steel sheet without coating 2 Copper plating 3. Tin plating 4 Burned-in area

Claims (6)

[Claims] Claim 1: A magnetic material having a plating layer is used in whole or in part, and after being combined and formed into a formed body,
A method for manufacturing a combination magnetic material that is produced by creating a burning state between materials, characterized in that the burning is caused by a direct heating method. 2. The method for producing a combination magnetic material according to claim 1, wherein the method is carried out under a reducing atmosphere. 3. The method for producing a combination magnetic material according to claim 1 or 2, wherein the method is carried out under pressure molding. [Claim 4] Claim 1, in which a direct current heating method is used;
3. The method for producing a combined magnetic material according to 2 or 3. 5. The method for producing a combination magnetic material according to claim 1, wherein pressure molding is carried out using a direct current heating method and with electrodes that are directly energized. 6. The method for producing a combined magnetic material according to claim 1, 2 or 3, using an induction heating method.