JPH11176649A - Magnetic core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify detaching of an annular magnetic core and a pedestal, reduce manhour and improve quality, by fixing the annular magnetic core to the holding pedestal via an expansion member by using a clamping band. SOLUTION: A pedestal 2 forms a circular recess conforming with the outer peripheral shape of an annular magnetic core 1, and the annular magnetic core 1 is arranged in the recess. A clamping band 3 is arranged on the outer periphery of the annular magnetic core 1 and fixed to anchor parts 6 of the pedestal 2 by using screws, and the annular magnetic core 1 and the pedestal 2 are fixed. In this case, one side fixing part is fixed via a spring as an expansion member. Regarding the annular magnetic core 1, movement in the radial direction can be restrained by the clamping band 3 and movement in the axial direction can be restrained by a protruding part 5 of the pedestal 2, so that the annular magnetic core 1 can be surely fixed to the pedestal 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a noise filter,
The present invention relates to a ring-shaped magnetic core used for a zero-phase reactor or the like.

[0002]

2. Description of the Related Art Heretofore, in order to reduce unnecessary radiation noise and conduction noise from a power supply line, a power supply line is wound around a ring-shaped magnetic core to form a noise filter.

FIG. 3 is a perspective view of a conventional magnetic core for a noise filter. This is a method in which a ring-shaped ferrite core 51 housed in a resin case is used, a fastening band (screw-type band) 52 is attached to the outer periphery thereof, and the fastening band 52 and the pedestal 53 are fixed by spot welding. is there. Then, it is mounted at a predetermined position using the mounting hole 54 of the pedestal 53, and the power line is wound around the magnetic core 51,
A noise filter was configured.

[0004]

In the conventional structure, the magnetic core and the pedestal are fixed by spot welding. For this reason, the spot welding requires a lot of man-hours, and the spot welding has variations in strength, and it is necessary to improve both cost and quality. Furthermore, after the core was fixed to the pedestal, the core could not be removed and changed.

In the case where the magnetic core is housed in a protective case and fixed with a tightening band, the expansion and contraction of the protective case and the expansion and contraction of the tightening band with respect to temperature change are different. There was a problem of change.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a new magnetic core structure which can easily fix the magnetic core to the base and can be removed.

[0007]

The present invention comprises a ring-shaped magnetic core, a pedestal for holding the ring-shaped magnetic core, and a tightening band for fixing the ring-shaped magnetic core to the pedestal. It is fixed to the pedestal via an elastic member.

In the present invention, the ring-shaped magnetic core is often placed in a resin case for the purpose of insulation and protection. In this case, when heat treatment or the like is performed, the resin case may shrink. As described above, when the resin case shrinks, a dimensional difference from the tightening band fixed to the pedestal (a difference in the behavior of the tightening band of the resin case with respect to a temperature change) occurs.
In some cases, a problem may occur that the magnetic core that should have been fixed is not fixed. In the present invention, since the fastening band is fixed via the elastic member, the fixed state can be maintained by the elasticity even if the resin case subsequently contracts. That is, it is possible to suppress a change in the fixing strength of the magnetic core and the pedestal with respect to a temperature change, and to maintain a good fixing state.

Further, in the present invention, an engaging portion for fixing the tightening band via an elastic member is formed on the pedestal. This facilitates fixing of the tightening band.

Further, in the present invention, the pedestal has a concave portion conforming to an outer peripheral shape of the magnetic core, and projections for positioning the magnetic core are formed on both sides of the concave portion.
Thereby, it is possible to improve sitting when the magnetic core is arranged on the pedestal, and to suppress the axial movement of the magnetic core. Further, in the present invention, the tightening band is arranged on an outer peripheral side of the magnetic core.

Further, in the present invention, the ring-shaped magnetic core is a wound magnetic core of an amorphous magnetic alloy ribbon or a nanocrystalline soft magnetic alloy ribbon, and is housed in a protective case.

An amorphous magnetic alloy and a nanocrystalline soft magnetic alloy obtain a magnetic core having desired characteristics by a heat treatment process.
When winding a thin ribbon made of this amorphous magnetic alloy and nanocrystalline soft magnetic alloy to form a wound core, putting it in a resin case, fixing it to the pedestal with a tightening band, and then performing a heat treatment step,
After the heat treatment, the resin case shrinks. Without using the elastic member in the present invention, when the fastening band is fixed to the pedestal at normal temperature and subjected to heat treatment, after the heat treatment, the resin case shrinks, the fastening state of the fastening band is loosened, and the magnetic core comes off the pedestal. Causes malfunction. However, according to the present invention, the fastening band can maintain the state in which the magnetic core is fixed to the pedestal even after the heat treatment, because of the intervention of the elastic member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view and FIG. 2 is a perspective view of an embodiment according to the present invention. This embodiment includes a ring-shaped magnetic core 1, a pedestal 2, and a tightening band 3,
A ring-shaped magnetic core 1 is arranged on a pedestal 2 and is fixed integrally with a tightening band 3.

This embodiment will be described in detail. The pedestal 2 has an arc-shaped concave portion 4 that matches the outer peripheral shape of the ring-shaped magnetic core 1.
A locking portion 6 for fixing the tightening band 3 is formed. A plurality of protrusions 5 are formed on both sides of the recess 4 for positioning the magnetic core 1 and preventing the magnetic core from being displaced in the axial direction. In addition, pedestal 2
Is formed with a mounting hole 7.

The ring-shaped magnetic core 1 is arranged in the recess 4 of the pedestal 2. Then, the tightening band 3 is arranged on the outer periphery of the ring-shaped magnetic core 1 and is screwed to the locking portion 6 of the pedestal 2 to fix the ring-shaped magnetic core 1 and the pedestal 2. At this time, one of the fixing portions is fixed via the spring 8. Thus, the ring-shaped magnetic core 1 is restrained from moving in the radial direction by the tightening band 3, is restrained from moving in the axial direction by the protrusion 5 of the pedestal 2, and is firmly fixed to the pedestal 2. Further, it is possible to maintain a favorable fixed state with respect to a temperature change. Also, 2
You may fix in all places via an expansion-contraction member.

As the elastic member, a so-called spring member is preferably used. In the above-described embodiment, a coil spring is used. This coil spring is a preferred example, but is not limited to this. If the coil spring has a telescopic mechanism whose circumferential dimension can be changed after being fixed with a tightening band,
The operation and effect of the present invention can be obtained.

According to this embodiment, since the magnetic core and the pedestal are fixed by the tightening band, the conventional spot welding process can be eliminated. Also, a projection is formed on the pedestal,
Since the magnetic core is positioned, even when the magnetic core and the pedestal are fixed by the tightening band, the workability is extremely good because the magnetic core is in the positioned state. Further, since the tightening band is removable, the magnetic core can be changed later. Further, even when the resin case of the magnetic core shrinks due to heat treatment or the like, the fixed state can be maintained.

The material of the magnetic core of the present invention may be ferrite, an amorphous magnetic alloy, a nanocrystalline soft magnetic alloy, or the like. In particular, a wound core of a nanocrystalline soft magnetic alloy ribbon has excellent magnetic properties and is extremely useful as a zero-phase reactor.

[0019]

According to the present invention, the magnetic core and the pedestal can be easily and firmly fixed, and the number of steps can be reduced and the quality can be improved. Further, it has a feature that the fixed state can be maintained even when the magnetic core (protective case) dimension changes due to a temperature change or the like. Also, the magnetic core can be removed, and various changes can be made. Further, it is particularly useful as a zero-phase reactor.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment according to the present invention.

FIG. 2 is a perspective view of one embodiment according to the present invention.

FIG. 3 is a perspective view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ring-shaped magnetic core 2 Pedestal 3 Tightening band 4 Concave part 5 Projection part 6 Locking part 7 Mounting hole 8 Telescopic member (spring)

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Katsuhiro Ogura, Inventor Katsuhiro 70-2, Minamisakaemachi, Tottori City, Tottori Pref.

Claims (5)

[Claims] 1. A ring-shaped magnetic core, a pedestal for holding the ring-shaped magnetic core, and a tightening band for fixing the ring-shaped magnetic core to the pedestal, wherein the tightening band is attached to the pedestal via an elastic member. A magnetic core characterized by being fixed. 2. The magnetic core according to claim 1, wherein a locking portion for fixing the tightening band via an elastic member is formed on the pedestal. 3. The pedestal has a concave portion conforming to the outer peripheral shape of the magnetic core, and projections for positioning the magnetic core are formed on both sides of the concave portion. The described magnetic core. 4. The magnetic core according to claim 1, wherein the tightening band is arranged on an outer peripheral side of the magnetic core. 5. The ring-shaped core is a wound core of an amorphous magnetic alloy ribbon or a nanocrystalline soft magnetic alloy ribbon,
2. The device according to claim 1, wherein the device is housed in a protective case.
The described magnetic core.