JPH01272102A - Adhesive for laminated core and laminated electromagnetic core for electric apparatus using same - Google Patents

Abstract

PURPOSE:To improve an excitation characteristic of a laminated electromagnetic core and, especially, to promote the improvement of efficiency in the manufacture of the laminated electromagnetic core according to a block method by containing 20-70% of a magnetic fine pulverulent body in a weight ratio. CONSTITUTION:In order to fill a gap between mating faces of laminated cores without sharply lowering a magnetic resistance, it is required that a particle of a magnetic fine pulverulent body is fine; it is desirable that its particle diameter is 5mum or lower; as long as the particle is fine, any magnetic fine pulverulent body can be used; malleable iron, an Fe-Si alloy powder, an Fe-Al alloy powder or the like can be used singly or by combining them appropriately. Regarding a mixture ratio of the magnetic fine pulverulent body to an adhesive resin base material, it is required that a mixture percentage of the magnetic fine pulverulent body is the mixture percentage or higher which is sufficient to reduce the magnetic resistance at the gap 4 between the mating faces of the iron cores and that the percentage is the mixture percentage or lower which can maintain an electrically insulating state between fine pulverulent bodies and can maintain a sufficient bonding force between the mating faces; when a range is 20-70% in a weight ratio, such an action effect can be achieved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an adhesive for laminated cores and a laminated electromagnetic core for electrical equipment using the same, and more specifically to an adhesive and an adhesive for improving the magnetization characteristics of a laminated electromagnetic core. This invention relates to a laminated electromagnetic core with excellent magnetization characteristics using the same.

[Conventional technology]

In general, electromagnetic cores for electrical equipment are made by punching cores of predetermined dimensions from steel plates, weighing them to a predetermined thickness, stacking them correctly, and then abutting and welding them, or using pins, keys, adhesives, etc. It is formed by fixing it in one piece using. The magnetic properties of the electromagnetic core formed in this way depend on the material used, the processing strain mainly due to punching, the presence or absence of magnetic annealing in the final stage, and the annealing conditions. The thickness also depends on the shape of the joint.

[Problem to be solved by the invention]

In the electromagnetic core as described above, the abutment surface is almost always a punched cross section. To explain this using FIGS. 1 and 2, the droop that occurs when punching the iron core 1.2,
Due to the inclination of the shear plane, the presence of fracture planes, etc., voids 4 are created in the abutment surfaces 3 of the laminated core, which increases magnetic resistance and tends to deteriorate the magnetization characteristics of the electromagnetic core.

Therefore, during punching, efforts have been made to improve the dimensional accuracy and the punched cross section so that these voids 4 are minimized, but sufficient results have not been achieved. Furthermore, recently methods have been adopted in which the cores are made into blocks by caulking, welding, etc., in order to reduce the labor burden of stacking the cores into a predetermined number of layers. , when the cores are stacked and fixed, the positional fluctuations of each core are added together, and the gap 4 at the abutting surface 3 tends to increase as shown in Fig. 2.As a result, the magnetization characteristics of the electromagnetic core deteriorate. , fluctuations are likely to occur, and the adoption or rejection of the blocking method is determined by whether priority is given to reducing labor load or magnetization characteristics, which is an obstacle to the widespread use of the blocking method.

This invention was made in view of the above-mentioned circumstances, and its purpose is to solve the problems caused by air gaps on the abutting surfaces of electromagnetic cores and to improve the magnetization characteristics of laminated electromagnetic cores for electrical equipment. .

[Means to solve the problem]

To achieve the above object, the present invention provides a laminated core adhesive that is used to bond the abutting surfaces of the laminated cores when manufacturing an electromagnetic core in which two sets of laminated cores collide to form a closed magnetic circuit. It contains 20 to 70% fine powder by weight and is electrically insulating, and is used in a laminated electromagnetic core for electrical equipment in which two sets of laminated cores abut against each other to form a closed magnetic circuit. are bonded together with an electrically insulating laminated iron core adhesive containing 20 to 70% by weight of magnetic fine powder.

[Effect]

The electrically insulating laminated iron core adhesive of the present invention containing 20 to 70% by weight of magnetic fine powder acts to improve the magnetic properties of the cores when applied to the abutting surfaces of two sets of laminated iron cores. The magnetic fine powder used in this invention needs to have fine particles, with a particle size of 5 μm or less, in order to fill the voids on the abutting surfaces of the laminated iron core without significantly reducing magnetic resistance. This is desirable.

The magnetic fine powder may be of any kind as long as the particles are fine, such as pure iron, Fe-3i alloy powder, Fe-A1 alloy powder, Fe-3i-A1 alloy powder, Fe- Ni alloy powder, Fe-Co alloy powder, etc. can be used alone or in an appropriate combination.

The adhesive resin matrix blended with the magnetic fine powder in the adhesive for laminated iron cores of this invention covers the surface of the magnetic fine powder and firmly fixes the abutting surfaces while ensuring electrical insulation between the fine powders. For example, epoxy resin, acrylic resin, cyanoacrylate resin, modified acrylate resin, etc. can be used.

Regarding the mixing ratio of the magnetic fine powder and the adhesive resin base material, the mixing ratio of the magnetic fine powder should be at least enough to reduce the magnetic resistance of the gap between the abutting surfaces of the iron core, and the electric current between the fine powders should be maintained. It is necessary that the mixing ratio is below that which can maintain an insulating state and maintain sufficient adhesion between the abutting surfaces.
In the present invention, such effects are achieved when the mixing ratio of the magnetic fine powder in the total amount of adhesive is in the range of 20 to 70% by weight.

〔Example〕

Using 50H1000 (according to the new JIS standard) non-oriented electrical steel sheet as the core material, a V-swaged El type laminated core with a width of 48 mm and a lamination thickness of 35 nun was manufactured. In this case, when abutting the E core and the first core to form a stacked electromagnetic core for a closed magnetic circuit, an epoxy resin two-component adhesive resin base material with a particle size shown in Table 1 is applied to the abutting surface. The EI type laminated electromagnetic cores of Examples 1 to 3 and Comparative Examples 1 to 4 were prepared by applying and curing the adhesive prepared by mixing and kneading the fine particle iron powders according to the proportions shown in the same table. Obtained. Table 1 shows the results of measuring the magnetic properties of these electromagnetic cores.

As is clear from the measurement results in Table 1, the laminated electromagnetic core whose abutting surfaces are bonded with the adhesive for laminated cores of the present invention requires about 10% less excitation current than the comparative example, and also has no load. Loss characteristics have also been improved.

〔Effect of the invention〕

As is clear from the above description, this invention uses a laminated core adhesive containing 20 to 70% by weight of magnetic fine powder to adhere the abutting surfaces of the core, thereby improving the excitation characteristics of the laminated electromagnetic core. In particular, it can promote efficiency improvement in the production of laminated electromagnetic cores by the blocking method, and has great industrial value in the field of manufacturing electromagnetic cores for electrical equipment.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view showing an example of the abutting surfaces of a laminated electromagnetic core according to the prior art, and FIG. 2 is an enlarged sectional view of an abutting surface of an example of the abutting surface of a laminated electromagnetic core formed by the blocking method according to the prior art. be. 1.2...Iron core, 3...Abutment surface, 4...
・Void. Patent applicant Hirohata Electrical Steel Center Co., Ltd. Agent Bunji Kamata

Claims (3)

[Claims] (1) In the laminated core adhesive used for adhering the abutting surfaces of the laminated cores when manufacturing an electromagnetic core in which two sets of laminated cores abut against each other to form a closed magnetic circuit, the magnetic fine powder is added at a weight ratio of 2
An electrically insulating laminated iron core adhesive characterized by containing 0 to 70%. (2) The adhesive for laminated iron cores according to claim 1, wherein the particle size of the magnetic fine powder is 5 μm or less. (3) A laminated electromagnetic core for electrical equipment, wherein the abutting surfaces of the laminated core are bonded using the adhesive according to claim 1 or 2.