JP2002025356A - Broadband shield cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a broadband shield cable with a shielding characteristics superior to that of the conventional ferrite block, having noise suppressing effect even at high frequency area and strong impact resistance, which is light and not bulky. SOLUTION: For the broad band shield cable, replacing conventional ferrite core, at least one or a plurality of impact resistant rubbers or a synthesized soft resins, combined with soft magnetic alloy powder, which are light and not bulky, molded and formed into a tape cut into a prescribed length, or a magnetic tape, or a tube cut into a prescribed length, are divided into a plurality of blocks and arranged on the shield cable at least at one position or with prescribed distance with each other. As the second case, in order to broaden the frequency band for noise suppression, the soft magnetic alloy powder is combined to at least two kinds of rubbers or synthesized soft resins with different frequency band, and formed into a tape or a tube, and divided into a plurality of blocks, and arranged on the shield cable at least at one position or with prescribed distance with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention not only has a shielding performance equal to or higher than that of a ferrite core used for conventional EMI measures of a cable, but also has an effect of suppressing noise even in a high frequency region. Light and,
The present invention relates to a broadband shielded cable that is not only bulky but also resistant to impact, and more particularly to a broadband shielded cable used as an interface cable for digital equipment.

[0002]

2. Description of the Related Art When an alternating current flows through a cable connecting electronic devices, a magnetic field is generated around the cable, and an electric field is generated in a space where the magnetic field changes. The magnetic field and the electric field propagate in the same space as electromagnetic waves. This affects the electronic device as radiation noise directly to the human body or an electronic device in proximity or from a cable connected to the electronic device. As a countermeasure against such noise, the cable is covered with a metal having good conductivity and shielded. Further, a method of attaching a ferrite core to prevent noise emission and inflow from a cable has been adopted. When a cable is inserted into a ferrite core, the ferrite core functions to absorb most of the magnetic field generated around the cable.

[0003]

However, the conventional ferrite core has problems such as being heavy and easily broken.
In general, ferrite cores are often attached to the input / output part of the cable (near the connector). However, the ferrite core is bulky, and it is necessary to increase the spacing between the connectors on the device side, increase the strength of the cable, and reinforce the cable. There is. During transportation, installation, or after installation of the cable to which the ferrite core is attached, there is a possibility that the cable may be broken and damaged by external force, drop impact, or the like. Also, in order to increase the shielding effect, it is necessary to increase the number of attachments and increase the volume of the ferrite core,
In practice, performance is limited. In the case of a cable, increasing the number of shielding layers in order to increase the shielding effect made the cable itself thicker, harder and less flexible, which was not practical. This phenomenon was particularly remarkable when a magnetic tape such as an iron-based tape was used. In order to solve such problems, not only has the same or better shielding performance as conventional ferrite cores,
There has been a demand for a broadband shielded cable that has a noise suppressing effect even in a high-frequency region and is not only light and bulky but also resistant to impact.

[0004]

In order to solve these problems, the present invention replaces the conventional ferrite core, and the first aspect of the present invention is to provide a lightweight, non-bulky, impact-resistant rubber or soft rubber. Compounding soft magnetic alloy powder with synthetic resin of
A molded or cut tape or magnetic metal tape cut to a predetermined length or a tube cut to a predetermined length and injection-molded and cut to a predetermined length is arranged on a shielded cable in at least one or a plurality of blocks at predetermined intervals. A broadband shielded cable characterized in that: Second, in order to widen the frequency band of noise suppression, soft magnetic alloy powder was blended with at least two types of rubber or soft synthetic resin having different frequency bands, molded and cut to a predetermined length. A broadband shielded cable characterized in that a tape or a magnetic metal tape or an injection-molded tube cut to a predetermined length is divided into at least one or a plurality of blocks at predetermined intervals in a shielded cable. is there.

[0005]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a broadband shielded cable according to an embodiment of the present invention;

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) shows a tape or magnetic metal tape formed by mixing a soft magnetic alloy powder with rubber or a soft synthetic resin, cutting into a predetermined length, or injection molding into a predetermined length. It is sectional drawing of the broadband shielded cable of this invention which applied the cut | disconnected tube to the shielded cable. As is apparent from the drawing, the present invention provides a rubber or a shielded cable 6 in which a shield tape or a shield braid 4 is provided on a cable provided with a plurality of insulated core wires 7 and a power supply wire 8 as necessary. The structure is such that a soft magnetic alloy powder is blended with a soft synthetic resin, and a molded or cut tape or magnetic metal tape 2 cut to a predetermined length or a tube 3 formed by injection molding and cut to a predetermined length. . The insulation resistance of the tape or tube formed by mixing soft magnetic alloy powder with rubber or soft synthetic resin is 1.0 × 10
^As high as ¹⁰ Ω, a method in which an adhesive portion or the like was provided on the back surface of the tape and directly attached to the shield portion showed the most preferable result for the noise suppression effect. However, the effect is effective even if it is performed from above the sheath. Here, a typical example of a tape formed by mixing a soft magnetic alloy powder with a rubber or a soft synthetic resin, and then molded and cut into a predetermined length is a rubber or a synthetic resin kneaded with permalloy or ferrite. Is mentioned. Representative examples of the magnetic metal tape include a cobalt-based amorphous ribbon and a tape in which an aluminum foil is laminated on a cobalt-based amorphous ribbon. Further, typical examples of the tube include rubber or synthetic resin kneaded with permalloy or ferrite. FIG. 1 (B) shows a tape or magnetic metal tape or injection-molded tape formed by mixing a soft magnetic alloy powder with rubber or a soft synthetic resin into a predetermined length, and cutting into a predetermined length. 1 is a side view of a first embodiment of the present invention in which one tube is attached to a shielded cable with a connector. The noise suppression effect is controlled by the tape length and tape width. If the winding thickness is thick and bulky when the cable outer diameter is large and the tape length is long, a shape having a wide tape width may be selected to reduce the number of windings. FIG. 1 (c) shows a tape or magnetic metal tape or injection-molded tape formed by mixing a soft magnetic alloy powder with rubber or a soft synthetic resin into a predetermined length, and then cutting into a predetermined length. FIG. 6 is a side view of a second embodiment of the present invention, in which a tube is divided into a plurality of blocks at predetermined intervals in a shielded cable with a connector. If the flexibility of the cable is required, reduce the tape width in this way, divide it into multiple blocks,
Arrange them at appropriate intervals. FIG. 1D shows a tape obtained by blending a soft magnetic alloy powder with rubber or soft synthetic resin having different frequency bands, molding and cutting to a predetermined length and a magnetic metal tape or injection molding, FIG. 11 is a side view of a third embodiment of the present invention in which the characteristics of each frequency band are combined by combining tubes cut into lengths. When extending the frequency band, a soft magnetic alloy powder is blended with rubber or a soft synthetic resin having a different frequency band as described above, molded, cut into a predetermined length, cut into a tape or a magnetic metal tape or injection molded. By combining tubes cut to a predetermined length, the characteristics of each frequency band are combined. For the noise suppression effect in each frequency band, an appropriate number of blocks is arranged as described above. Next, FIG. 2 shows the load effect of the conventional ferrite core and two types of magnetic tapes (A and B) of the present invention, and the conventional ferrite core and two types of magnetic tape of the present invention (A and B) and the load effect of combining the magnetic tapes. FIG. 9 is a comparison characteristic diagram. Specifically, as a sample, a ferrite core and two types of magnetic tape
The one attached to a long single wire was used. As is clear from the figure, the magnetic tape A of the present invention has a frequency band almost equal to that of the ferrite core. It can be seen that the load effect (the amount of noise attenuation) is increased by attaching two magnetic tapes A of the present invention. The magnetic tape B of the present invention
Has a higher frequency band than the ferrite core and the magnetic tape A.
It can be seen that the load effect (the amount of noise attenuation) increases in the frequency band of. In addition, it can be seen that when one magnetic tape A and one magnetic tape B of the present invention are attached, the frequency characteristics of each one are combined. Thus, according to the broadband shielded cable of the present invention, it is clear that the same or better results are obtained as compared with the conventional one.

In this embodiment, a shielded cable in which a drain wire and a shield tape or a braided braid are wound around an insulated core wire and a power supply wire is shown as an example. However, this is merely a representative example, and the present invention is not limited to this. Absent. Therefore, the present invention is not limited to the shielded cable, but may be an object intended for shielding, for example, a connector itself or various deformed special-shaped products, and it goes without saying that it is within the scope of the present invention.

[0008]

As is clear from the above description, the broadband shielded cable 1 of the present invention has the following features. It is not bulky because it is not necessary to increase the interval between the device side connectors, increase the strength of preventing the cable from being disconnected, and reinforce it. 2. Regarding the handling of the cable, it is resistant to shock because damage and characteristic deterioration due to external force and drop impact are less likely to occur during transport, installation and after installation. 3. Lightweight due to tape or tube. 4. Since the selection range of the control of the shielding effect is broadened depending on the size of the tape or the tube and the number of the tapes or tubes attached, the diversification is possible. 5. Even in the high-frequency region of the shielding effect, frequency characteristics unique to each tape or tube can be combined, and diversification is possible. Its industrial value is great because of its excellent effect.

[Brief description of the drawings]

FIG. 1 (a) shows a tape or a magnetic metal tape or an injection-molded tape formed by mixing a soft magnetic alloy powder with rubber or a soft synthetic resin, and cutting the same into a predetermined length. It is sectional drawing of the broadband shielded cable of this invention which applied the cut | disconnected tube to the shielded cable.
(B) is a rubber or soft synthetic resin mixed with a soft magnetic alloy powder, molded and cut into a predetermined length of tape or magnetic metal tape or an injection molded tube cut into a predetermined length. 1 for shielded cable with connector
FIG. 2 is a side view of the first embodiment of the present invention with the pieces attached.
(C) is a method in which a soft magnetic alloy powder is blended with rubber or a soft synthetic resin, and a molded or cut tape or magnetic metal tape or an injection-molded tube cut to a predetermined length. FIG. 9 is a side view of a second embodiment of the present invention in which a shielded cable with a connector is divided into a plurality of blocks at predetermined intervals and arranged. (D) A soft magnetic alloy powder is mixed with rubber or soft synthetic resin having different frequency bands, molded, cut to a predetermined length or a magnetic metal tape or injection-molded to a predetermined length. FIG. 13 is a side view of a third embodiment of the present invention in which the characteristics of each frequency band are combined by combining the cut tubes.

FIG. 2 shows a conventional ferrite core and a magnetic tape 2 of the present invention.
It is a load effect comparison characteristic figure of a seed (AB) and magnetic tape compounding.

[Explanation of symbols]

1 Broadband shielded cable of the present invention 2 Soft magnetic alloy powder mixed with rubber or soft synthetic resin, tape or magnetic metal tape molded and cut to predetermined length 3 Soft magnetic alloy with rubber or soft synthetic resin Tube mixed with powder, injection molded and cut to predetermined length 4 Shield tape or shield braid 5 Drain wire 6 Shielded cable 7 Insulated core wire 8 Power supply wire 9 Connector A Magnetic having almost the same frequency band as ferrite core Tape B Magnetic tape having a higher frequency band than magnetic tape A

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 9/00 H05K 9/00 L (72) Inventor Hirokuni Kobayashi 2-chome Shimoodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture No. 12-8 Oki Electric Wire Co., Ltd. (72) Inventor Tomo Miyazaki 2-12-8 Shimoodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture In-house Oki Electric Wire Co., Ltd. F term (reference) 4F071 AA02 AA10 AB12 AB17 AE14 AH12 BA01 BB05 BB06 BC01 BC05 BC17 4J002 AA011 AC001 DC006 DE046 GQ00 GR02 5E321 BB33 BB44 BB53 GG09 5G319 EA01 EB02 EC01 EC12

Claims (2)

[Claims] 1. A tape or magnetic metal tape formed by mixing a soft magnetic alloy powder with a rubber or a soft synthetic resin and cutting to a predetermined length, or a tube cut to a predetermined length by injection molding. A broadband shielded cable, wherein the shielded cable is divided into at least one or a plurality of blocks at predetermined intervals. 2. At least two different frequency bands
A soft magnetic alloy powder is blended with a kind of rubber or soft synthetic resin, molded and cut to a predetermined length, or a magnetic metal tape or an injection-molded, cut to length tube is cut into a shielded cable. A broadband shielded cable, wherein at least one or a plurality of blocks are arranged at predetermined intervals.