JPH0239403A - Method for fixing magnetic core - Google Patents

Abstract

PURPOSE:To decrease a deterioration of magnetic characteristics by shock or distortion and prevent deterioration with the passage of time by fasting with an adhesive an end face of a magnetic core which is formed by winding a magnetic alloy thin band or by fasting the end face of the magnetic core to a case to store the magnetic core or to a plate on which the magnetic core is fixed, with an adhesive. CONSTITUTION:After applying or injecting a specified amount of an adhesive to the inner face 31 of a case 3, a magnetic core 1 is put on it. Then, an adhesive is applied to an upper end face 11 of the magnetic core 1 or to the inner face of a case 2 and the case 2 is put on the upper end face of the magnetic core 1. After a certain time, the upper and the lower end faces 11, 12 of the magnetic core 1 and the cases 2, 3 are fixed to each other. For the adhesive, the one which has a viscosity so that it is not penetrated between layers of the magnetic core 1 which is made by winding a magnetic alloy thin band and which has a hardness more than a specific value after cured is used.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for fixing an endless core (magnetic core) such as annular or rectangular, and more specifically, magnetic properties are likely to change (degrade) due to impact. The present invention relates to a method for fixing a magnetic core formed by winding a magnetic alloy ribbon such as a high magnetostrictive amorphous magnetic alloy ribbon.

(Prior art and its problems) A magnetic core obtained by winding an amorphous magnetic alloy ribbon is
It has excellent magnetic properties such as high saturation magnetic flux density and low coercive force. Among these, magnetic cores using Fe-based amorphous alloy ribbons have an exceptionally high saturation magnetic flux density, but they also have high saturation magnetostriction characteristics, so they are sensitive to shocks, stress, etc., and their magnetic properties tend to deteriorate.

In general, when a magnetic core made of amorphous magnetic alloy ribbon is used for a transformer, stress and impact cause a decrease in saturation magnetic flux density and an increase in coercive force, resulting in an increase in iron loss. When used as a magnet, the magnetic permeability μ deteriorates significantly in the low frequency range, and the inductance value decreases.

Note that the amorphous magnetic alloy ribbon is annealed at a temperature around the Curie temperature for the purpose of improving magnetic properties. However, this annealing causes the steel to lose its toughness and become brittle, resulting in a significant decrease in mechanical strength.

Therefore, when manufacturing cut cores that require cutting work or manufacturing magnetic cores for smooth chokes, it is difficult to cut them while annealed, so it is necessary to impregnate or mold the magnetic core with resin, harden it, and then cut it. , are using.

However, when the above-mentioned impregnation or molding is performed, there is a problem in that stress is applied to the magnetic core due to curing shrinkage and the magnetic properties deteriorate.

Therefore, manufacturers of magnetic cores and assemblers of magnetic cores are required to be extremely careful not to deteriorate the magnetic properties of the magnetic cores, and the cores are usually housed in a case.

Furthermore, as a solution to the above problem, for example, the fifth
As shown in the figure, when the magnetic core 1 is housed in a case 4, a cushioning material 5 such as silicone rubber is interposed inside the case 4. Further, there is one in which an adhesive material such as silicone grease is applied to the gap between the magnetic core 1 and the case 4. both,
This is an attempt to alleviate the impact through a buffering effect and prevent the deterioration of magnetic properties, but it has not achieved a decisive effect.

Furthermore, in Japanese Patent Publication No. 61-37762, a magnetic core is formed by winding an amorphous magnetic alloy ribbon around a metal ring,
A method for preventing deterioration of magnetic properties is described, but this method naturally requires a metal ring, and because the metal ring is used, the window area required for the winding is reduced. become.

An object of the present invention is to provide a method for fixing a magnetic core that solves the problems existing in the prior art.

(Means for Solving the Problems) A method for fixing a magnetic core according to the present invention includes: (1) an end face of a magnetic core formed by winding a magnetic alloy ribbon;
The case that houses the magnetic core is fixed with adhesive.

(2) An end face of a magnetic core formed by winding a magnetic alloy ribbon;
The fixing plate is fixed with adhesive.

(3) An adhesive is applied to the end surface formed by winding a magnetic alloy ribbon, and the end surface of the magnetic core is hardened.

(Function) Since the end face of the magnetic core and the case or fixing plate are fixed with adhesive, or the adhesive is applied to the end face of the magnetic core and cured, the magnetic core will not deform if it is subjected to impact due to dropping, etc. Therefore, the degree of deterioration of the magnetic properties is extremely small, and is significantly reduced compared to the conventional example.

(Example) A first example of the present invention will be described in detail based on FIG. In the figure, 1 indicates a magnetic core, and 2.3 indicates a case housing a pair of magnetic cores.

The magnetic core fixing method of the present invention is carried out as follows.

First, a predetermined amount of adhesive is applied or injected onto the inner surface 31 of the case 3, and the magnetic core 1 is placed thereon.

Next, a predetermined amount of adhesive is applied to the upper end surface 11 of the magnetic core 1 or the inner surface of the case 2, and the case 2 is placed on the upper end surface of the magnetic core 1. After a certain period of time, both upper and lower end surfaces of the magnetic core 1 are 11.12 and case 2.3 are fixed together.

At this time, it is of course possible to apply an adhesive to the inner surface of the case 2.3, and to house the magnetic core 1 between the cases 2 and 3 and press and secure them.

Note that the pair of cases 2.3 may have any shape as long as they can accommodate the magnetic core 1.

In addition, the adhesive has a viscosity that does not penetrate between the eyebrows of the magnetic core 1 formed by winding a magnetic alloy ribbon;
The condition is that it has a hardness of a certain value or more after curing, and it is desirable for work that it hardens at room temperature. According to experiments, epoxy resin adhesive manufactured by CI BA-GEIGY (resin agent AW108, curing agent HV953u)
obtained good results. Incidentally, the viscosity of the sample adhesive is when the mixing ratio (volume ratio) of the resin agent and curing agent is 1:1.
The hardness is approximately 35.0 OOcp (centipoise) at 25° C. and the hardness is 75-82 Shore D.

Figure 3 shows the magnetic permeability μ(
This is experimental data showing changes in ) at 1 kHz.

The amorphous magnetic alloy ribbon used in this experiment was Metglas 2605S-2 manufactured by Allied Co., Ltd. The dimensions of the magnetic core 1 were 37φ x 23φ - 15m□, and the inner dimensions of the case 2.3 that housed the magnetic core 1 were 39φ x 21.5φ. -16m
m (material is nylon 66, thickness 0.6 mm). In addition, in the experiment, the inductance at 1k) Iz was measured using YHP's impedance analyzer LF4192A for a sample that was dropped naturally from a height of 10 cm onto a 1 cm thick plywood board, and the magnetic permeability U was calculated from the measured value. . As you can see from this, it I! According to the present invention (curve (c)), the present invention (curve (c)) has a significant effect on untreated products (curve (a)) for which no measures have been taken against j Even when compared with the product coated with product model number 1211 (curve (b)), the change in magnetic permeability μ was about 1/10 of the effect obtained.

Next, a second embodiment will be described in detail based on FIG. 2.

In this embodiment, the end face of the magnetic core 1 and the fixing plate 8.9 are fixed with adhesive, and the experimental results are shown in the curve (E) of FIG. 4. In this case, the adhesive used was HYS-BAR (5 minute curing type) manufactured by Cemedine.

The curve (=) is a comparison of data obtained when using the same silicone rubber as the curve (b) in Figure 3.
This comparative data also proves that the magnetic core fixing method of the present invention is more effective than the prior art method in which the deterioration of magnetic properties is prevented by a buffering effect.

Further, in this embodiment, the fixing plate 8.9 is used in place of the case 2.3 of the first embodiment, so that material costs can be reduced. Further, if the present embodiment is adopted after the magnetic core 1 is formed by winding an amorphous magnetic alloy ribbon in a toroidal shape and is heat-treated, it is effective to prevent deformation of the magnetic core during subsequent transportation work and the like.

The fixing plates 8 and 9 used in this embodiment are made of a material that does not adversely affect the magnetic core 1, and are preferably made of a material with a small coefficient of thermal expansion.

Although the embodiments have been described above, the present invention is not limited to such embodiments, and instead of using a magnetic core storage case or a fixing plate, an adhesive is applied to the end face of the magnetic core to attach the magnetic core. Also included in the present invention are those with hardened end faces. In addition, it goes without saying that adhesives are not limited to adhesives in the narrow sense that are commonly referred to, but also include adhesives in a broader sense, such as casting agents and sealants that have equivalent physical properties. . Furthermore, the shape, material, etc. of the case or the fixing plate may be any as long as they conform to the gist of the present invention.

(Effects of the Invention) As described above, the method for fixing a magnetic core according to the present invention is to fix the end face of a magnetic core formed by winding a magnetic alloy ribbon in a toroidal shape with an adhesive, or to accommodate the end face of the magnetic core and the magnetic core. Since the case or the fixing plate is fixed with adhesive, the following effects are obtained.

(1) Deterioration of magnetic properties due to shock and distortion during transportation, assembly, etc. of the magnetic core can be significantly reduced.

(2) Moisture does not enter the gap (interlayer) between the windings of the magnetic alloy ribbon forming the magnetic core, so rust does not occur and deterioration of magnetic properties over time can be prevented.

(3) Since adhesive only needs to be used on the end faces, the amount of material used is significantly less than when the entire magnetic core is glued or molded with resin etc. (4) Metal rings are placed on the inner surface of the magnetic core Since this is not necessary, the winding window area can be increased, and the coil shape after winding does not need to be large.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view illustrating a first embodiment of the present invention, FIG. 2 is an exploded perspective view illustrating a second embodiment of the present invention, and FIG. FIG. 4 shows a change curve of the magnetic permeability of the magnetic core depending on the number of drops in the second embodiment, and FIG. 5 shows an explanatory diagram of a conventional method for fixing the magnetic core. 1...Magnetic core, 2.3...Case, 8.9...Fixing plate. Patent applicant Nagano Japan Radio Co., Ltd. 1 Figure 2 Figure 3 Number of falls (times) Figure 5 Figure 4 Number of falls (times)

Claims (3)

[Claims] (1) A method for fixing a magnetic core, characterized in that the upper and lower end surfaces of a magnetic core formed by winding a magnetic alloy ribbon are fixed to a case housing the magnetic core using an adhesive. (2) A method for fixing a magnetic core, characterized in that the upper and lower end surfaces of a magnetic core formed by winding a magnetic alloy ribbon are fixed to a fixing plate using an adhesive. (3) A method for fixing a magnetic core, comprising applying an adhesive to the upper and lower end surfaces of a magnetic core formed by winding a magnetic alloy ribbon, and hardening the end surfaces of the magnetic core.