JPH0221608A - Inductance element - Google Patents

Abstract

PURPOSE:To make it possible to manufacture an element in one baking step without grinding by assembling a first molded body and a second molded body, and forming a drum core. CONSTITUTION:Ferrite powder in which a binder and the like are mixed is pressed and molded. Thus, specified shapes are imparted to a first molded body 3 and a second molded body 4. Thereafter, baking is performed by one baking step. In this way, the sintered body of the first molded body 3 and the sintered body of the second molded body 4 are manufactured. Meanwhile, a piece of wire for a coil is wound around a jig having the approximately equal diameter as a coil supporting shaft 1 with a wire winding machine. Thus an air-core coil 6 is otherwise manufactured. Thereafter, the coil 6 is coupled on the outer surface of the coil supporting shaft 1 of the first molded body 3. A linking rod 8 of the second molded body 4 is inserted into a through hole 7 of the first molded body 3. The coil 6 is held between both flanges 2. Then, a bonding resin 9 is injected between the tip part of the linking rod 8 and the wall of the through hole 7 from the outer surface side of the flange 2 of the first molded body 3. The linking rod 8 is fixed in the through hole 7 in this way so that the rod 8 does not come out. Thus an inductance element A is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inductance element in which a coil is wound around a drum core, and is used as, for example, a peaking coil or a filter coil.

[Background technology]

A conventional inductance element has a structure in which a coil is wound around an integral drum core 15 made of ferrite.

However, since it is difficult to directly mold a drum-shaped molded body, the drum core 15 is manufactured as shown in FIGS. 7 to 9. That is, first, ferrite powder mixed with a binder etc. is press-molded to form a cylindrical molded body 20 as shown in FIG. The cylindrical molded body 20 after firing is chucked in a processing machine such as a lathe (not shown).
While rotating the cylindrical molded body 20, grind the outer periphery of the cylindrical molded body 20 with a grinding tool 21 such as a diamond grindstone as shown in FIG. 8 until it reaches the position shown by the imaginary line in FIG. A drum-shaped body 22 is manufactured by cutting the outer periphery of the cylindrical molded body 20. After this, the drum-shaped body 2
2 is fired to produce a drum-shaped drum core 1 as shown in Figure 9.
5 was manufactured.

Then, as shown in FIG. 10, one flange 12 of the drum core 15 is gripped by the chuck 23 of the winding machine.
The coil was wound around the outer periphery of the coil support shaft 11 of the drum core 15 using an automatic or manual winding machine.

[Problem to be solved by the invention]

Conventional inductance elements of this type have used an integral drum core made by grinding the outer periphery of a cylindrical molded body into a drum shape. Shape Grinding and Knee ■Requires 4 steps including final firing, especially the time-consuming steps of firing twice and grinding, making the manufacturing process of the drum core complex and the manufacturing cost very high. there was. In addition, in drum-shaped grinding of a cylindrical molded body, the end of the cylindrical molded body is gripped by a chuck such as a lathe, and the central part of the cylindrical molded body is ground thinly with a grinding tool, so that the flange gripped by the chuck is There are problems such as cracks (A) shown in Fig. 11 occurring due to the tightening of the chuck, and neck bends (B) shown in Fig. 12 occurring at the thinly shaved end of the coil support shaft. there were.

Therefore, an object of the present invention is to make it possible to manufacture a drum core without performing any grinding process, and also to make it possible to obtain a drum core by a second firing process.

[Means to solve the problem]

Therefore, in the inductance element of the present invention, the coil support shaft can be fixed by combining a first molded body having one flange at one end of the coil support shaft and a second molded body having at least the other flange. It is characterized in that a drum core is formed with flanges provided at both ends, and a coil is wound around the outer periphery of the coil support shaft of this drum core.

[Effect]

As described above, the drum core is formed by combining the first molded body and the second molded body, and one flange and the other flange are formed by combining the first molded body and the second molded body, respectively. Because they are separated, neither the first molded product nor the second molded product has a constricted shape in the center that is difficult to mold, unlike a drum core, and both the first molded product and the second molded product can be obtained by one molding. I can do it. Therefore, the drum core can be manufactured by three steps: (1) forming a molded body, (2) firing a molded body, and (2) assembling a molded body. In this way, the firing process is only required once, the grinding process is eliminated, and the assembly process in the manufacturing process of the present invention is a simple operation, so the drum core can be easily manufactured according to the present invention, and the manufacturing cost is reduced. will also be significantly reduced. Furthermore, since there is no grinding process, it is possible to avoid defects such as chipped flanges and broken necks of the coil support shaft due to tightening of the chuck during the grinding process, improving the yield rate.

〔Example〕

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

The drum corer is made of a magnetic material such as ferrite, and as shown in FIGS. 1 and 2, it is assembled from a first molded body 3 and a second molded body 4 which are separate from each other. ing. The first molded body 3 is one in which a disk-shaped flange 2 is integrally molded on one end of a round bar-shaped coil support shaft 1, and a through hole 7 is formed at the center of the coil support shaft 1 and the flange 2. It is provided. Further, the second molded body 4 has a connecting rod 8 protruding from the center of the flange 2 having a disk shape. Here, the inner diameter of the through hole 7 is slightly larger (for example, about 0.1 to 0.21) than the outer diameter of the connecting rod 8, and the length a of the connecting rod 8 is the length a of the first molded body 3. It is equal to length b or slightly shorter. Since both the first molded body 3 and the second molded body 4 have no constricted portions, they can be directly molded.

That is, by press-molding ferrite powder mixed with a binder etc., the shapes shown in FIG. 1 are given to the first molded body 3 and the second molded body 4, respectively. The sintered body of the first molded body 3 and the sintered body of the second molded body 4 are produced by firing in one firing process.

On the other hand, an air-core coil 6 as shown in FIG. 1 is separately manufactured by winding a coil wire around a jig having an outer diameter approximately equal to that of the coil support shaft 1 using a winding machine.

Thus, as described above, the first and second molded bodies 4 (
After manufacturing three parts, a sintered body) and an air-core coil 6, as shown in FIG. Insert the connecting rod 8 of the molded body 4 into the through hole 7 of the first molded body 3, and insert the coil 6 between both flanges 2. Next, connect from the outer surface side of the flange 2 of the first molded body 3. Adhesive resin 9 is injected into the tip of the rod 8 and into the through hole 7, and the connecting rod 8 is fixed in the through hole 7 using the adhesive resin 9 so as not to come off, thereby forming an inductance element as shown in FIG. get an A.

Therefore, this inductance element A can be easily manufactured by one molding process, one firing process, and one assembly process. In addition, as described above, since the air-core coil 6 that has been previously wound by a winding machine is inserted into the coil support shaft 1, the winding machine can be used with the chuck of the winding machine as in the case where the coil 6 is wound around a drum corer. The flange 2 gripped by the coil support shaft 1 may be chipped.
In addition, the coil 6
Since it is manufactured using a winding machine using special jigs, it can be produced at a higher speed than when winding it around a drum corer.

Although not shown, the second embodiment of the present invention has a first molded body (
After combining a sintered body (sintered body) and a second molded body (sintered body) into a drum shape, and bonding the first molded body and the second molded body together with an adhesive resin to make a core drum, An inductance element is manufactured by winding a coil wire around the outer periphery of the coil support shaft of this core drum using a winding machine.

What is shown in FIG. 5 is a third embodiment of the present invention, in which a first molded body 3 is provided with a disk-shaped flange 2 at one end of a round bar-shaped coil support shaft 1, and a disk-shaped flange 2 is provided at one end of a round bar-shaped coil support shaft 1 2, and a second molded body 4 having a through hole 10 with an inner diameter approximately equal to the outer diameter of the coil support shaft 1 at the center of the flange 2;
The tip of the coil support shaft 1 of the first molded body 3 is inserted into the through hole 10 of the second molded body 4, and the first and second molded bodies 3 and 4 are bonded together with adhesive resin. 9 to form the drum core 5.

What is shown in FIG. 6 is a fourth embodiment of the present invention, in which a first molded body 3 is provided with a flange 2 at one end of a coil support shaft 1, and a flange 2 is provided at one end of the coil support shaft 1 and the flange 2. A through hole 7 was bored in the center, and in the second molded body 4, a flange 2 was provided at one end of the coil support shaft 1, and a connecting rod 8 was made to protrude from the other end of the coil support shaft 1. It is something.

Then, the connecting rod 8 is inserted into the through hole 7, and the first and second molded bodies 3, 4 are bonded together with the adhesive resin 9, and the coil support shaft 1 of the first molded body 3 and the second molded body are bonded together. The coil support shaft 1 of the molded body 4 constitutes the coil support shaft 1 of the drum corer.

〔Effect of the invention〕

According to the present invention, the drum core can be easily manufactured by assembling the image molded body after manufacturing the first molded body and the second molded body, and the manufacturing process can be simplified. , the manufacturing cost of the inductance element can also be reduced. In particular, compared to the conventional example,
The two firing steps can be completed in one firing step, and the grinding step can also be eliminated, making it possible to greatly simplify the manufacturing process. Furthermore, since a grinding process of the molded body is not required, defective products such as chipped flanges and broken necks of the coil support shaft do not occur during the grinding process, and the yield rate of non-defective products is improved.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention, FIG.
Figures 3 and 4 are front views showing the assembly procedure of the same as above;
FIG. 5 is a partially cutaway front view showing another example of the present invention, and FIG.
Figure 7 is a partially cutaway front view showing still another example of the present invention.
8 and 9 are perspective views showing a conventional drum core manufacturing method, FIG. 10 is a schematic front view showing the winding process of the conventional example, and FIGS. 11 and 12 show the drawbacks of the same. It is an explanatory diagram. 1... Coil support shaft 2... Flange 3...
First molded body 4... Second molded body 5... Drum core 6... Coil

Claims (1)

[Claims] (1) By combining a first molded body having one flange at one end of the coil support shaft and a second molded body having at least the other flange, flanges can be provided at both ends of the coil support shaft. An inductance element characterized by forming a drum core and having a coil wound around the outer periphery of a coil support shaft of the drum core.