JP2003338223A - Cable for data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable for data, which can improve skew characteristics. <P>SOLUTION: Four insulated wires 15 formed by covering a conductor 21 with an insulator 23 are provided, the insulated wires 15 are arranged on a diamond inclusion equipped with 4 recessed portions each having substantially the same curvature as that of the insulated wire 15, the diamond inclusion 13 and the insulated wires 15 are twisted with each other, an aluminum tape 19 is wound around the outer periphery thereof to form a shield layer, and the outer periphery thereof is covered with a housing 17, thereby forming the cable 11 for data. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data cable used in a high speed data transmission network, and more particularly to a data cable capable of improving skew characteristics.

[0002]

2. Description of the Related Art Conventionally, as a data cable, FIG.
As shown in FIG. 4, a data cable having a structure in which four insulated electric wires 103 are collectively arranged around a round interposition 101, a metal tape is vertically attached or wound around the outer circumference, and the outer circumference is covered with a jacket 105. It has been known.

[0003]

A circular interposition 1 shown in FIG.
In the case of a data cable using 01, a round interposition 101
Since the four insulated electric wires 103 are arranged with the center as the center, it is effective to secure the distance between the opposed insulated electric wires 103.

However, in the manufacturing process in which the insulated wire 103 is arranged on the outer periphery of the round interposition 101, the insulated wire 1
When the feeding tension of 03 is unbalanced or when the arrangement is disturbed by the stress due to bending, the four insulated wires 10
3 has a line length difference, which causes a propagation delay time difference (hereinafter,
Called skew. ) Was reduced.

Further, since the contact area between the round interposition 101 and the insulated electric wire 103 is small, the insulated electric wire 103 is likely to move in the direction parallel to the cross section. There is a problem that the skew characteristic deteriorates.

Further, the storage area network (S
With the widespread use of high-speed data transmission networks such as AN (Storage Area Network), there has been a demand for the spread of data cables that can minimize the difference in signal propagation delay time as a transmission line for transmitting differential signals.

The present invention has been made in view of the above,
An object of the invention is to provide a data cable that can improve skew characteristics.

[0008]

The invention according to claim 1 is
An insulated electric wire formed by covering the central conductor with an insulator, a diamond-shaped interposition having a concave portion having a curvature approximately the same as the curvature of the outer circumference of the insulated electric wire, and an outer circumference twisted along the concave portion of the insulated electric wire. The gist of the invention is that it comprises a metal tape that shields the metal tape and an outer cover that covers the metal tape.

A second aspect of the present invention is characterized in that the curvature of the concave portion is larger than the curvature of the outer circumference of the insulated wire and is up to this curvature × 1.5 times.

According to a third aspect of the present invention, the diamond-shaped interposition has at least four recesses, and the shortest distance between the facing recesses is the diameter of the insulated wire times 0.414 times, and the center point of the facing insulated wire is The gist is that the distance is formed to be the diameter of the insulated wire × 1.414 times.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the structure of a data cable 11 according to an embodiment of the present invention. FIG. 2 is a side view of the data cable 11. Further, FIG. 3 is a sectional view of the diamond-shaped interposition 13. Furthermore, FIG.
It is a figure which shows the correlation of 3 and the insulated wire 15.

In the data cable 11, as shown in FIG. 1, an insulated electric wire 15 is arranged in each of four recesses 25 provided in a diamond-shaped diamond-shaped interposition 13, and the diamond-shaped interposition 13 and the insulated wire 15 are twisted together. A metal tape 19 is vertically attached or wound around the outer circumference, and the outer circumference is covered with a jacket 17.

As shown in FIG. 3, the diamond-shaped interposition 13 has a curvature substantially the same as the curvature of the insulated wire 15, or the insulated wire 1
Four concave portions 25 having a curvature of 5 times up to 1.5 times are provided.

Further, as shown in FIG. 4, the diamond-shaped interposition 13 is arranged with the center of each insulated wire 15 offset by 90 degrees on the circumference of the diameter (A) × 1.414 times (B) of the insulated wire 15. It is formed so that the distance between the facing concave portions 25 becomes (diameter of insulated wire 15) × 0.414 times (C) when it is pressed.

By forming such a diamond-shaped interposition 13, the contact area between the concave portion 25 of the diamond-shaped interposition 13 and the side surface of the insulated wire 15 is increased, and further the adjacent insulated wire 15 pushes out the other insulated wire 15. Since there is no contact, the arrangement of the insulated wire 15 can be stabilized.

Returning to FIG. 1, each insulated wire 15 has a conductor 21.
Is formed by covering an insulator 23 such as a resin, and each insulated wire 15 is arranged in the recess 25 of the diamond-shaped interposition 13.

Next, the cable specifications of the data cable 11 will be described with reference to FIG.

The conductor 21 has a diameter of 0.6 mm, and when the conductor 21 is covered with the insulator 23, the diameter of the insulated wire 15 is 1.8 mm. The conductor 21 may be a silver-plated copper wire or a tin-plated copper wire, and when these copper wires are used, it is effective in improving the amount of signal attenuation on the high frequency side. The insulated wire 15 is not limited to a single wire, but may be a fuel wire.

The insulator 23 is preferably made of polyethylene PE and may have a foam structure or a skin foam structure. The use of polyethylene PE as the insulator 23 is effective for improving electric characteristics and flexibility.

The metal tape 19 is, for example, an aluminum tape or a copper tape having a thickness of 0.06 mm and a width of 12 mm. A resin layer or an adhesive layer is provided on one side of the aluminum tape so that it can be easily wound. It is preferable to improve the adhesion between the object 17 and the insulator 23. The winding pitch of the metal tape 19 is, for example, 20 mm to improve flexibility.

The diamond-shaped interposition 13 has a side of 1.3 mm and a diagonal line length of 1.84 mm. The curvature of the recess is preferably substantially the same as the curvature of the insulated wire 15 or the curvature of the insulated wire 15 up to 1.5 times. The reason why the curvature is up to 1.5 times is that the material cost increases significantly if the curvature exceeds this value. Further, if the curvature becomes 1.5 times or more, the cable diameter becomes larger than the conventional cable diameter, so that there is a problem in the laying surface that the cable cannot be passed through the conduit.

The material of the diamond-shaped interposition 13 is preferably low friction polyethylene PE. When this is used, the friction between the diamond-shaped interposition 13 and the insulated wire 15 can be significantly reduced, so that in the manufacturing process, the line length difference caused by the imbalance of the sending tension is not changed in the elastic region of the insulated wire 15. It is possible to return with tension.

At this time, the outer diameter of the data cable 11 is
It becomes about 6.0 mm. As the outer cover 17, a recyclable eco-friendly material made of polyvinyl chloride PVC or a polyolefin material is preferable.

The above-mentioned eco-friendly material is composed of a halogen-free flame-retardant resin composition, and in particular, 20 parts by weight or more of metal hydroxide is added to 100 parts by weight of polyolefin resin.
Less than 0 parts by weight and 2 parts by weight or more and less than 10 parts by weight of a flame retardant auxiliary are added, the specific gravity is 1.14 or less, the oxygen index is 24 or more and 34 or less, and when used as a coating material, J
It passes the 60 ° inclined combustion test established in IS C3005. Further, this eco-friendly material is made of a halogen-free flame-retardant resin composition, and particularly, with respect to 100 parts by weight of the polyolefin resin, 20 parts by weight or more and less than 50 parts by weight of metal hydroxide and 0.5 part by weight of red phosphorus. More than 2.5
Less than 1 part by weight and less than 1 part by weight and less than 6 parts by weight of carbon black are added, the specific gravity is 1.14 or less, the oxygen index is 24 or more and 34 or less, and it is established in JIS C3005 when used as a coating material. Those that pass the 60 ° inclined combustion test may be used.

Next, the function and effect of the data cable 11 will be described with reference to FIG.

First, the conductor 21 is covered with the insulator 23 to form the insulated wire 15, and four such insulated wires 15 are prepared. Then, each recess 2 of the diamond-shaped interposition 13
Insulated wire 15 is arranged in 5, and diamond-shaped interposition 13 and insulated wire 1
5 is twisted together, an aluminum tape 19 is wound around the outer circumference to form a shielding layer, and the outer circumference is covered with a jacket 17 to form a data cable 11.

As a result, the insulated wire 15 is arranged in the diamond-shaped interposition 13 provided with four recesses 25 having substantially the same curvature as that of the insulated wire 15. By twisting these, the centripetal force of the insulated wire 15 is improved and the insulated wire 15 is insulated. Since the contact area between 15 and the diamond-shaped interposition 13 can be increased, it is possible to prevent the insulated wire 15 from moving in the direction parallel to the cross section. Also,
By protecting the outer circumference with the aluminum tape 19 and the outer jacket 17, it is effective to further prevent the insulated wire 15 from moving.

By using low friction polyethylene PE as the material of the diamond intervening 13, the diamond intervening 13 and the insulated wire 15
Since it is possible to significantly reduce the friction with the wire, even if the sending tension becomes unbalanced in the manufacturing process and a line length difference occurs, the tension can be returned by the tension in the elastic region of the insulated wire 15, so that the skew characteristic The decrease can be prevented. As a result of measuring the skew characteristic of the data cable of the present invention, the skew characteristic was 20 ps / m.

[0030]

According to the present invention as set forth in claim 1, the insulated wire is arranged in a diamond-shaped interposition having a recess having a curvature substantially the same as the curvature of the outer periphery of the insulated wire, and twisted together with the diamond-shaped interposition and the insulated wire to form an outer periphery. It is possible to prevent the insulated wire 15 from moving in the direction parallel to the cross section by shielding with a metal tape and further covering the outer cover.

According to the second aspect of the present invention, the curvature of the recess is larger than the curvature of the outer circumference of the insulated wire.
By setting the ratio to 1.5 times, the contact area between the diamond-shaped interposition and the insulated wire becomes large, so that the insulated wire can be prevented from moving in the direction parallel to the cross section. Further, it is possible to suppress an increase in material cost and to pass the material through a prescribed electric wire tube.

Further, according to the present invention of claim 3, the rhombic interposition has recesses on all four sides having a curvature substantially the same as the curvature of the outer circumference of the insulated wire, and the distance between the facing recesses is the diameter of the insulated wire. × 0.414 times, when the insulated wire is further placed in the recess, the center of the insulated wire is the diameter of the insulated wire ×
By being formed so as to be arranged on the circumference of 1.414 times, it is possible to prevent the insulated electric wire 15 from moving in the direction parallel to the cross section, and to make the line length difference of the insulated electric wire almost zero. Therefore, the skew characteristic can be improved.

[Brief description of drawings]

FIG. 1 is a data cable 1 according to an embodiment of the present invention.
It is sectional drawing which shows the structure of 1.

FIG. 2 is a data cable 1 according to the embodiment of the present invention.
It is a side view of 1.

FIG. 3 is a cross-sectional view of a diamond-shaped interposition 13.

FIG. 4 is a diagram showing a correlation between diamond-shaped inclusions 13 and insulated wires 15.

FIG. 5 is a data cable 1 according to the embodiment of the present invention.
It is a table showing the cable specifications of 1.

FIG. 6 is a data cable using a conventional round interposition 101.

[Explanation of symbols]

11 Data cable 13 diamond intervening 15 insulated wire 17 jacket 19 metal tape 21 conductor 23 Insulator 25 recess 101 Round type 103 insulated wire 105 jacket 107 Aluminum tape

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiji Ohashi             1440 Rokuzaki, Sakura City, Chiba Prefecture Fujikura Ltd.             Sakura office F-term (reference) 5G319 DA07 DB01 DC05

Claims (3)

[Claims] 1. An insulated wire formed by coating an insulator on a central conductor, a diamond-shaped interposition having a recess having a curvature substantially the same as the curvature of the outer circumference of the insulated wire, and the insulated wire extending along the recess. A cable for data, comprising a metal tape that shields the twisted outer periphery and an outer cover that covers the metal tape. 2. The curvature of the recess is larger than the curvature of the outer circumference of the insulated wire, and the curvature × 1.
The data cable according to claim 1, wherein the data cable is up to 5 times. 3. The diamond-shaped interposition has at least four recesses, the shortest distance between the facing recesses is the diameter of the insulated wire × 0.414 times, and the distance between the center points of the facing insulated wires is Insulated wire diameter ×
The data cable according to claim 1 or 2, wherein the cable is formed so as to have a length of 1.414 times.