JPH1174678A - Noise absorption core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noise absorption core wherein magnetic efficiency is raised by lighter weight and improved degree of freeness. SOLUTION: A base part 1a and sandwiching parts 1b and 1c extending in a specified direction from one end and the other end of the base part 1a, are provided, which is a composite magnetic body comprising a soft magnetic powder and organic binder whose rubber hardness is 60 or less. The sandwiching parts 1b and 1c are extending in the direction slightly tilted inward against the base part, so that their tip ends contact each other. A flat cable is inserted in a space surrounded by the base part 1a and the sandwiching parts 1b and 1c while the sandwiching parts 1b and 1c are pressed outward against each other, vertically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic noise preventing device, and more particularly to a noise absorbing core that is mounted around a cable and absorbs and removes electromagnetic noise propagating through the cable.

[0002]

2. Description of the Related Art In recent years, electronic devices using high frequencies, such as digital electronic devices, have become widespread. In particular, mobile communication devices using a quasi-microwave band or a microwave band have been remarkably spread. In such mobile communication devices typified by mobile phones, high-speed operation is attempted, so that line-to-line coupling increases, interference due to radiated noise or the like occurs, and the normal operation of the devices is hindered. Not a little high-frequency electromagnetic interference has occurred.

[0003] Electromagnetic noise that propagates through connection cables of electronic devices and the like also causes the above-mentioned high-frequency electromagnetic interference.
As shown in FIG. 6A, a ferrite core 101 having a U-shaped cross section is well known as an electromagnetic noise preventing device for absorbing and removing the electromagnetic noise. The ferrite core 101 is fixed to the flat cable 102 as shown in FIG. In this example, as shown in FIG. 6B, 1 is much shorter than L, so that the influence of the open end is small.

[0004]

However, since the above-described conventional noise suppression device is a sintered body such as ferrite, there is a problem of cracking and cracking due to dropping during operation or contact at the time of installation. Furthermore, since the size of the sintered body increases, the weight cannot be ignored, and the flexibility is poor, so that the degree of freedom in attaching the cable is poor. In addition, since it has an open end, a closed magnetic circuit cannot be formed, and magnetic efficiency deteriorates.

An object of the present invention is to provide a noise absorbing core which can solve the above-mentioned problems, can be reduced in weight and size, and can improve magnetic efficiency.

[0006]

According to the present invention, there is provided a composite magnetic material comprising a soft magnetic powder and an organic binder having a rubber hardness of 60 or less, comprising a base, one end of the base and one end of the base. A noise-absorbing core is provided, which extends from the other end in a predetermined direction and includes first and second holding portions for holding the cable.

Further, according to the present invention, there is provided a noise absorbing core, wherein the composite magnetic material further contains a crosslinking agent.

Further, according to the present invention, first and second contact portions are provided at tips of the first and second holding portions, respectively, so that the base portion, the first and second holding portions are provided. A noise absorbing core is obtained, wherein a closed magnetic circuit is formed by the portion and the first and second contact portions.

Further, according to the present invention, after the cable is fitted between the first and second holding portions, a stopper is attached to a tip of the first and second holding portions to close the magnet. A noise-absorbing core is obtained, characterized in that a path is formed.

Further, according to the present invention, the base material comprises a soft magnetic powder and an organic binder having a rubber hardness of 60 or less, and extends in a predetermined direction from a base and one end and the other end of the base, respectively. A first composite magnetic body provided to face each other and having first and second holding portions for holding a cable;
The first composite magnetic body has the same shape as that of the first composite magnetic body, and is formed of a second composite magnetic body having a larger distance between the holding portions than that of the first composite magnetic body. The noise absorbing core is characterized in that the noise absorbing core is characterized in that the closed magnetic circuit is formed by being incorporated between the holding portions of the two composite magnetic materials.

Further, according to the present invention, there is provided a noise absorbing core, wherein the first and second composite magnetic bodies further contain a crosslinking agent.

Further, according to the present invention, there is provided a noise absorbing core, wherein the soft magnetic powder is a flat Fe-Al-Si alloy powder, and the organic binder is an elastomer.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a structure of a noise absorbing core according to a first embodiment of the present invention.
As shown in FIG. 1, the noise absorbing core 1 includes a base 1a,
Each of the holding portions 1b and 1c extends from one end and the other end of the base 1a in a predetermined direction. Nipping parts 1b, 1
c extends in a direction inclining slightly inward with respect to the base such that the tips contact each other. The flat cable (not shown) pushes and expands the holding portions 1b and 1c vertically (in the direction of the arrow in the figure), and is inserted into a space surrounded by the base 1a and the holding portions 1b and 1c. When inserting the cable, clamp part 1
The ends of b and 1c open once in the direction of the arrow in the figure, but since they have a spring property, a reaction force returning in the opposite direction acts to hold the cable firmly. After the insertion, the tips of the holding portions 1b and 1c come into contact again, and the base 1a and the holding portions 1b and 1c
At 1c, a closed magnetic circuit is formed.

The above-described noise absorbing core 1 is a composite magnetic material composed of an insulating soft magnetic material and an organic binder. Hereinafter, a method for manufacturing the noise absorbing core according to the present embodiment will be described. First, the compounding is as follows: 83.7 parts by weight of a flat soft magnetic powder composed of an Fe—Al—Si alloy having an anisotropic magnetic field having an average particle diameter of 10 μm and an aspect ratio of 5 or more, 14.8 parts by weight of an elastomer having a hardness of 60, And 1.5 parts by weight of a crosslinking agent. In the above composition, if a crosslinking aid is added, the physical properties of the crosslinked product can be further improved, but the effect of the present invention can be obtained even without the addition.

The above mixture is formed into a sheet by a rolling roll, and formed by a single-screw extruder 11. As shown in FIG. 5A, the sheet-like composite magnetic material is oriented and arranged in a desired size and flat magnetic powder at a die portion 11a of an extruder 11, and a cut for inserting a cable is provided. An extruded composite magnetic material sample 21 having a shape as shown in FIG. 1 is obtained. The sample 11a is inserted into the crosslinked layer 13 through the insertion guide 12. The cross-linking layer 13 is a device for heating a cross-linking agent constituting the composite magnetic body to improve flexibility. The crosslinked layer 13 is heated to 160 ° C., and the flow speed of the sample 21 is 8 to 1
The rotation speed of the extruder 11 is set to 5 so that it is about 0 minutes.
Adjust within the range of ２０20 ppm. In addition, a vacuum facility may be used for the crosslinked layer, and the crosslinked layer may be separately cooled and cut to a required length. These settings vary depending on the blending of the magnetic powder and the like, the temperature distribution of the flow path of the sample, the screw and the cylinder, and are changed according to the required characteristics.

After passing through the cross-linking layer 13, the insertion guide 12
Through the cooling layer 14 to obtain a cooled sample 22. The cooling layer 14 includes a heat sink for air cooling and a cooling unit of an air cooling fan. The cooling method may be water cooling or oil cooling. The sample 22 coming out of the cooling layer 14 is cut into a desired size. In addition, the temperature of the screw part of the extruder 11 and the temperature in the cylinder are set at 70 ° C. so that the rubber is not deteriorated.
The temperature of the head is set to 90 ° C. and the temperature of the die is set to 12 ° C.
Set to 0 ° C. FIG. 5B is a front view of a die portion of the extruder 11. Further, a die portion may be used instead of the die portion. The crosslinked layer may be cooled separately and cut to a required length using a vacuum facility.

Here, in the case of the noise absorbing device having the shape as shown in FIG. 1, if necessary depending on the degree of bending of the prepared sample, the ends of both holding portions for holding the cable 3 as shown in FIG. Fix using the stopper 2.

When the cross-linking is not required, the equipment for the cross-linking layer 13 and the cooling layer 14 is unnecessary.
In addition, if the number of rotations of the extruder 11 is increased as required, the production amount can be increased. Of course, at that time, the molding conditions including the compounding are changed.

Next, a second embodiment of the noise absorbing core will be described with reference to FIG. In FIG. 3, the noise absorbing core 4 includes a base 4a, and first and second holding portions extending in parallel from one end and the other end of the base 4a, respectively, for holding a cable (not shown). 4b, 4c
It is composed of First and second contact portions 4d and 4e are provided at the tips of the first and second holding portions 4b and 4c, respectively. The base 4a, the first and second holding portions 4b,
4c and the first and second contact portions 4d and 4e form a closed magnetic circuit. In the present embodiment, the opening is eliminated and the contact area with the cable is increased as compared with the first embodiment to improve the magnetic efficiency.

The method of manufacturing the noise absorbing core according to the second embodiment is the same as that of the first embodiment except that the structure of the die is different.

Next, a third embodiment of the noise absorbing core will be described with reference to FIG. In FIG. 4, the third
The noise absorbing core according to the embodiment has the same shape as the first composite magnetic body 5 and the first composite magnetic body 5 having a substantially U-shaped cross section, and the distance between the sandwiching portions 6a and 6b is the first. Composite magnetic material 5
Of the second composite magnetic body 6 larger than that of
Of the second composite magnetic body 6 with the holding portions 6a and 6
b. Also in the present embodiment, a closed magnetic path is formed by the two composite magnetic bodies 5 and 6.

The method of manufacturing the noise absorbing core according to the third embodiment is the same as that of the first embodiment except that the structure of the die is different.

[0023]

According to the present invention, since it is composed of a soft magnetic powder and an organic binder, it is possible to prevent cracking and spattering due to dropping during work or contact during installation.

Further, according to the present invention, the weight is reduced and the flexibility is improved as compared with the prior art, so that the degree of freedom in attaching the cable is also improved.

Further, according to the present invention, the magnetic efficiency is improved because the closed magnetic circuit is formed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a noise absorbing core according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a stopper is attached to a tip of a holding portion of the noise absorbing core of FIG. 1;

FIG. 3 is a diagram showing a noise absorbing core according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a noise absorbing core according to a third embodiment of the present invention.

5A and 5B are diagrams for explaining a method of manufacturing the noise absorbing core of FIG. 1, and FIG. 5B is a cross-sectional view illustrating a structure of a die used in an extrusion process.

FIG. 6A is a diagram showing a structure of a conventional noise absorbing core, and FIG. 6B is a front view of FIG.

[Explanation of symbols]

 1,4 Noise Absorbing Core 2 Stopper 3 Cable 5,6 Composite Magnetic Material 11 Extruder 12 Insertion Guide 13 Crosslinking Layer 14 Cooling Layer 31 Thermocouple

Continued on the front page (72) Inventor Yoshio Awakura 6-7-1, Koriyama, Taishiro-ku, Sendai-shi, Miyagi Pref.

Claims (7)

[Claims] 1. A composite magnetic material comprising a soft magnetic powder and an organic binder having a rubber hardness of 60 or less, wherein the composite magnetic body extends in a predetermined direction from a base and one end and the other end of the base, respectively. A noise absorbing core comprising a first and a second holding portion for holding a cable. 2. The noise absorbing core according to claim 1, wherein said composite magnetic material further contains a crosslinking agent. 3. A first and a second contact portion are provided at tips of the first and the second holding portions, respectively, and the base portion, the first and the second holding portions, and the first and the second holding portions are provided. 3. The noise absorbing core according to claim 1, wherein a closed magnetic circuit is formed by the second contact portion. 4. A closed magnetic path is formed by fitting a cable between the first and second holding portions and then attaching a stopper to a tip of each of the first and second holding portions. The noise absorbing core according to claim 1, wherein: 5. A base comprising a soft magnetic powder and an organic binder having a rubber hardness of 60 or less, extending in a predetermined direction from one end and the other end of the base, and provided to face each other. A first composite magnetic body having first and second holding portions for holding a cable; and a first composite magnetic body having the same shape as the first composite magnetic body, wherein a distance between the holding portions is the first composite magnetic material. A second composite magnetic body larger than that of the body, wherein the first composite magnetic body is incorporated between sandwiching portions of the second composite magnetic body to form a closed magnetic circuit. Absorbent core. 6. The noise absorbing core according to claim 1, wherein the first and second composite magnetic bodies further contain a crosslinking agent. 7. The soft magnetic powder according to claim 1, wherein the soft magnetic powder is flat Fe-Al-S.
The noise absorbing core according to any one of claims 1 to 6, wherein the noise absorbing core is an i-alloy powder, and the organic binder is an elastomer.