JPS6055973B2 - Manufacturing method of powder magnetic core and powder magnetic core coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a powder magnetic core and a powder magnetic core coil using flaky magnetic powder.

When making powder magnetic cores, conventional magnetic powders have irregular shapes and many irregularities, so it is difficult to increase the packing density and improve the magnetic permeability by applying light vibrations. So far, powder magnetic cores have been made by mixing magnetic powder such as carbonyl iron or Centast with a binder, placing it in a mold, molding it under pressure comparable to IOT/c, and then heating and solidifying it.

Further, powder magnetic cores are usually made in an annular shape, and the winding work of relatively thick electric wires around the annular magnetic core is difficult to automate and must be done manually, resulting in high costs. The present invention focuses on the fact that flaky iron powder with few irregularities, amorphous alloys, etc. have been developed as magnetic powder in recent years, and uses this flaky magnetic powder to create a simple press that solves the above-mentioned drawbacks. An object of the present invention is to provide a method for manufacturing a powder magnetic core and a method for manufacturing a powder magnetic core coil. The present invention improves the packing density by intermittently applying direct current to the winding after or while filling a mold or container with a required winding with flaky magnetic powder to orient the flaky magnetic powder along the magnetic flux. A powder magnetic core and a powder magnetic core coil are manufactured by injecting an insulating resin with high fluidity and impregnating it into magnetic powder and solidifying it.

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 each show an example of the steps of the method for manufacturing a powder magnetic core according to the present invention. In FIG. 1, a winding 2 of a required number of turns is applied to the outer periphery of a bottomed cylindrical mold 1 made of paramagnetic material, a variable DC power source 4 is connected to the winding 2 via a switch 3, and a thin film is placed inside the mold 1. When the required amount of shaped magnetic powder 5 is filled and the switch 3 is turned on, the randomly arranged and bulky magnetic powder 5 is oriented along the magnetic flux generated by the winding 2, increasing the packing density.

Moreover, by controlling the direct current and turning the switch 3 on and off several times, the packing density can be increased to a level that allows a magnetic permeability large enough for practical use to be obtained. Next, in FIG. 2, with the switch 3 turned off, an insulating resin 6 with good fluidity is injected, impregnated into the magnetic powder 5, and heated and solidified, thereby solidifying the magnetic powder 5 in an oriented state. .

This heating is to promote solidification and only takes a short time.
Solidifies sufficiently even at room temperature. Thereafter, as shown in FIG. 3, it is extracted from the mold 1 to obtain a rod-shaped powder magnetic core 7. FIGS. 4 to 7 each show an example of the process of manufacturing a circular powder core common mode choke coil according to the present invention. In FIG. 4, semi-annular insulating cases 8a and 8b have a shape in which an annular hollow body is equally divided along the diameter, one end of the outer periphery is left connected to each other, and the outer periphery of the other end is partially cut off. The windings 9a are connected to each other so that the number of turns is the same and the polarity is opposite to each other.
, 9b.

By adopting such a shape, even thick electric wires can be automatically wound. In addition, if the strength of the insulating case is low, it is preferable to take appropriate reinforcing measures such as inserting a flexible temporary core material into the hollow part only during winding to prevent the case from collapsing due to winding. . Next, as shown in FIG. 5, the insulating cases 8a and 8b are butt-joined, and a funnel 10 is fitted into the cutout that forms the butt part, and the variable DC power supply 4 is connected in parallel to the windings 9a and 9b via the switch 11. connection,
The switch 11 is turned on to the winding 9a side, and the flaky magnetic powder 5 is gradually filled from the funnel 10.

While filling the required amount of magnetic powder 5, the switch 11 is alternately switched to the windings 9a and 9b several times. In this way, the magnetic powder 5 is filled into the insulating case 8 in a highly dense state while being oriented along the magnetic flux generated by the winding. In FIG. 6, a highly fluid insulating resin 6 is injected into the magnetic powder 5 with the switch 11 turned off. Impregnate and heat to solidify. After this, when the funnel 10 is removed and the necessary treatment is performed on the resection area,
As shown in FIG. 7, a common cord choke coil 12 is obtained. When the coercive force of the magnetic powder is relatively small, by injecting the resin 6 while regulating the orientation by applying current to either one of the windings 9a and 9b, the orientation of the magnetic powder due to the injection of the resin 6 can be improved. Eliminates the disturbance of Figures 8 and 9
The figures show an embodiment in which an annular powder magnetic core coil is made by applying a single winding, and FIG. 8 is a front view, and FIG. 9 is a side sectional view of the insulating case.

The insulating case of this example includes a substantially C-shaped hollow insulating case 13 that has a gap 14 that allows automatic winding by cutting out a part of a hollow annular body, and an auxiliary case 15 that has an opening-shaped cross section that fits into the gap 14.
It consists of

As shown in FIG. 9, the insulating case 13 is made by joining, for example, a main body 13'' having a substantially C-shaped groove with a cross-sectional opening shape and a substantially C-shaped plate portion 13'' that closes the upper surface of the groove. The winding 16 is automatically wound on the insulating case 13 through the gap 14 and the switch 3 is closed.
After connecting the variable direct current 4 through the auxiliary case 15 and joining the auxiliary case 15 to the gap 14, the annular powder magnetic core choke coil is obtained through the same steps as in the previous embodiment. Now, based on the magnetic permeability of the air-core coil of the winding 16, the method of the present invention can obtain a magnetic permeability that is 7 to 8 times higher, whereas the method of the present invention using conventional magnetic powder with many irregularities When applied or simply filled with flaky magnetic powder without applying pressure, the magnetic permeability was about 4 times higher, confirming that the present invention is superior.

FIG. 10 shows another example of the insulating case used for the annular powder core common mode choke coil as shown in FIG.
Partition plate 1 that equally divides the center hole of the insulating case 13 in Fig. 8
7 is integrally provided to insulate the two windings applied to the insulating case 13.

Automatic winding is possible even with such a shape, and an annular powder magnetic core coil is produced by inserting the auxiliary case 15 into the gap 14 and following the same steps as in the previous embodiment. Note that the method of manufacturing the annular case is not limited to the above-mentioned embodiment, and if the insulating case 13 is split in the axial direction as shown in FIG. You can also get

As explained above, according to the present invention, powder magnetic cores and powder magnetic core coils can be manufactured without using large-scale pressure molding equipment, each process can be easily automated, and therefore manufacturing costs can be reduced. can be significantly reduced.

[Brief explanation of drawings]

FIGS. 1 to 3 are diagrams showing process examples of the method for manufacturing a powder magnetic core according to the present invention, and FIGS. 4 to 7 are diagrams showing process examples of the method for manufacturing a powder magnetic core coil. 8 and 9 are a front view and a side sectional view of an example of the insulating case used in the present invention, and FIG. 10 is a front view of another example of the insulating case. In the figure, 1 is a bottomed cylindrical type, 2, 9a, 9b, 16 are windings,
3 and 11 are switches, 4 is a variable DC power supply, 5 is a flaky magnetic powder, 6 is an insulating resin, 8a, 8b, and 13 are an insulating case, 10 is a funnel, and 17 is a partition plate.

Claims (1)

[Scope of Claims] 1. A wire is wound around a shaped material provided with a hollow portion of a predetermined shape, and a direct current is intermittently applied to the winding wire while the hollow portion is filled with flaky magnetic powder, and the winding is further insulated. A method for producing a powder magnetic core, which comprises obtaining a powder magnetic core formed into a predetermined shape by impregnating and solidifying a resin. 2. After applying the required winding to a container made of insulating resin and having a hollow part of a predetermined shape, filling the container with flaky magnetic powder or intermittently applying direct current to the winding while filling the container, and A method for producing a powder magnetic core coil, which comprises forming a magnetic core by impregnating and solidifying an insulating resin.