JPS62156225A - Production of thin plate core - Google Patents

Abstract

PURPOSE:To simplify production stages by forming an insulating film on a plate before working. CONSTITUTION:The suspension of powder of a metallic oxide such as magnesium oxide or alumina is brought into contact with the surface of a metallic plate such as an Ni-Fe alloy plate to form the insulating metallic oxide layer of <=20mum thickness. The plate having the insulating film is worked into the required shape and the resulting worked plate or the laminate of such worked plates is annealed to produce a thin plate core.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a thin plate core suitable as a magnetic helad core, E core, F core, etc.

[Technical background of the invention and its problems] For example, magnetic herad cores have conventionally been formed of a single thin plate made of a ferromagnetic material such as a Ni-Fe alloy;
Alternatively, if better properties are required, a core made of multiple (2 to 6) laminated thin plates mentioned above is known, and in the case of a core with this laminated structure, the @It is necessary to insulate between the layers of the laminate.

Conventionally, the following method has been used to manufacture this thin plate core.

That is, first, a metal plate material such as a Ni--Fe alloy is pressed into a desired shape, magnetically annealed, and then a plurality of the processed plates are bonded together with a bonding agent to provide lamination and interlayer insulation.

However, this method has the problem that it is easily deformed due to handling after annealing, that it is difficult and complicated to stack with high precision, and that the manufacturing cost increases due to this time and effort.

In addition, in the case of E core, F core, ■ core, etc., metal plates are punched into the desired shape, placed side by side on a tray, and each sheet is coated with inorganic powder to form an insulating coating. Annealing was performed. However, in this case as well, there was a drawback that it took time and effort to apply the powder, resulting in high manufacturing costs.

[Purpose of the Invention] The present inventors focused on the fact that the above-mentioned problems are caused by forming an insulating film on the workpiece after punching, and developed an insulating film on the workpiece before being processed. It has been found that the subsequent steps can be simplified if the formation is performed.

The present invention was made based on the above findings, and
It is an object of the present invention to provide a method for manufacturing a thin plate core that simplifies the manufacturing process and can therefore be manufactured at low cost.

[Summary of the Invention] In other words, the method for manufacturing a thin plate core of the present invention involves coating a metal plate with an inorganic insulating material, forming the metal plate into a desired shape, and annealing the obtained processed plate or a laminate made by laminating the processed plates. It is characterized by being

The metal plate material used in the method of the present invention may be one commonly used as a material for thin plate cores, such as a Ni--Fe alloy plate.

In addition, magnesium oxide,
Examples include a method in which metal oxide powder such as alumina is made into a suspension and brought into contact with the surface of the metal plate by coating, dipping, or the like. In this case, the particle size of the metal oxide powder is preferably 10 μm or less. Further, the thickness of the insulating coating is preferably 20 μm or less.

The insulating laminated metal plates are, for example, pressed into a predetermined shape and then arranged as they are on a tray, or after the resulting process is formed into an embossed layer and then laminated together, they are heated with argon gas. In a non-oxidizing gas atmosphere such as gas, nitrogen gas, hydrogen gas, etc., approximately 11
Magnetic annealing is performed at 00'C.

[Embodiments of the invention] Next, the present invention will be explained by examples.

Example: After immersing a thin plate of Ni-Fe alloy with a thickness of 0.1 mm in an aqueous slurry of magnesium oxide powder with a particle size of 2 μm,
Dry at 0'C for 30 minutes. Next, this thin plate was stamped into a desired shape using a punch press, and after rough embossing, six 1* processed plates were stacked. This laminate was magnetically annealed by heating at 1100'C for 60 minutes in a nitrogen gas atmosphere to produce a thin plate core.

The thin plate core thus obtained had good magnetic permeability at high frequencies and good sensitivity over a wide frequency band. In addition, the loss due to eddy currents was low, making it an excellent magnetic rad core.

[Effects of the Invention] As explained above, according to the thin plate core manufacturing method of the present invention, an insulating coating is formed on a metal plate, so the manufacturing process is simplified compared to conventional methods, and costs can therefore be reduced. realizable.

Applicant: Toshiba Corporation Agent Patent Attorney Suyama Sa Voluntary writing of procedural amendments) January 27, 1986 stomach

Claims (2)

[Claims] (1) A method for producing a thin plate core, characterized in that a metal plate is coated with an inorganic insulator, then formed into a desired shape, and the resulting processed plate or a laminate made by laminating the processed plates is annealed. . (2) The method for manufacturing a thin plate core according to claim 1, wherein the inorganic insulating coating is contacted with a suspension of metal oxide powder.