JPH08106819A - Shielded multi-core cable - Google Patents

Abstract

(57) [Abstract] [Purpose] In a multi-core cable mainly composed of an interface between control devices, it can be wired in a short time without the need for processing (wiring) a ground line, and also improves the efficiency of use of signal lines. [Structure] A wire consisting of a conductor and an insulator around which an aluminum shield is wound, and is composed of a wire with an aluminum shield, a braided shield, and an outer cover. [Effect] Noise (crosstalk, reflection) that intrudes into the cable from the outside and noise (crosstalk, reflection) that intrudes from the adjacent wire can be suppressed, and all aluminum shielded wires can be used as signal wires. This leads to a reduction in the number of cables. Further, since the processing (wiring) of the ground line is unnecessary, the throughput is improved and the work man-hour can be reduced. Compared with the manufacturing cost, the processing cost is 85% compared to the conventional
The number of steps can be reduced.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a central processing unit (CP
U) and a process I / O device (PI / O) interface mainly used as a shielded multi-core cable applicable to a control device, especially a shield suitable for a control panel of a chemical plant or a cable for a control computer. The present invention relates to a multi-core cable.

[0002]

2. Description of the Related Art Cable wiring between control devices such as an interface between a central processing unit (CPU) and a process input / output device (PI / O) has various wirings in order to prevent noise (crosstalk, reflection). The method has been adopted.

That is, one pair of twisted wires is used as a signal wire and the other is used as a ground wire, or a flat cable is allocated and arranged such as a ground wire, a signal wire, and a ground wire. is there.

FIG. 4 is a cross-sectional view of a conventional multi-core cable (twisted wire), and FIG. 5 shows its connection method. First, an example of a multi-core cable (twisted wire) considering noise (crosstalk, reflection) will be described.

As shown in FIG. 4, a core conductor 1 and an insulator 3 are provided.
The conventional multi-core cable is composed of two pairs of the strands 5 composed of and, a plurality of the strands 5 are bundled into a twisted wire 7, the braided shield 9 is covered, and the outer skin 11 is covered thereon. (Twist line). The processing of the braided shield 9 is
As shown in FIG. 5, the terminal 13 is crimped and grounded.
To use as.

The signal line 15 and the ground line 17 are pressed against the contacts 21 on the connector 19, respectively. FIG. 5 shows a wiring situation when such three cables 23, 25, 27 are used.

[0007]

In the above-mentioned conventional technique, noise (crosstalk, reflection) that intrudes into the cable from the outside can be suppressed, but noise (crosstalk, reflection) that intrudes from the adjacent wires 5 can be suppressed. Can not be suppressed.

When it is desired to use one signal line in order to prevent noise (crosstalk, reflection), it is necessary to process (wiring) one or more ground lines.
Therefore, the use efficiency of the signal line of one cable is poor, and the work efficiency is deteriorated because the processing (wiring) of the ground line is indispensable.

An object of the present invention is to provide a multi-core cable mainly for an interface between control devices, which does not require processing (wiring) of a ground line and can be wired in a short time, and which improves a signal line use efficiency. Is to provide a cable.

[0010]

In order to solve the problems of the prior art, according to the present invention, an aluminum shield (hereinafter abbreviated as aluminum shield) is wound around a wire of a multi-core cable composed of a core conductor and an insulator. By adopting an integrated cable structure, it has a collective conduction function and is used as a ground to improve the signal line usage efficiency.

[0011]

As described above, by winding a shielding material such as an aluminum shield having a collective conduction function around the wire of a multi-core cable composed of a core conductor and an insulator and using it as a ground, Noise (crosstalk, reflection) that enters the equipment and noise (crosstalk, reflection) that enters from adjacent wires can be suppressed. In addition, it is possible to have a bundle conduction function by bundling a plurality of the strands, electrically connecting the strands of the strands, covering the strands with a braided shield wire, and further covering the sheath.

Further, according to the present invention, ground lines (a plurality of lines) which are indispensable as a countermeasure against noise (crosstalk, reflection)
The processing of is unnecessary by using the collective conduction function as a ground through a shielding material such as a braided shield wire and an aluminum shield, and the number of usable signal wires is significantly increased.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is an element with an aluminum shield in which a shielding material such as an aluminum shield 6 is wound around an element wire 5 composed of a core conductor 1 and an insulator 3 as shown in FIGS. It is composed of a wire 8, a braided shield 9, an outer cover 11, and a drain wire 12. By wrapping the aluminum shield 6 around the wire 5 composed of the core conductor 1 and the insulator 3 to form a shielding layer, noise (crosstalk, reflection) entering from the adjacent wire 5 can be suppressed.

Further, by bundling a plurality of the aluminum shielded wires 8, the aluminum shields 6 of the wires 8 can be electrically connected. Braided shield 9 on it
To form a shield layer, which is then covered with the outer cover 11 to form an integrated cable structure.

That is, the strands of wire come into contact with each other in a circular braided shield 9 which accommodates a plurality of strands 8 with aluminum shield in a free space therein, and the braided shield 9 serving as a shield layer directly or indirectly. Are arranged in the free space so as to come into contact with each other, and the aluminum shield 6, which is a shielding layer for all the wires 8, is electrically connected to the braided shield 9.

As shown in FIG. 3, according to the wiring method of the present invention, the braided shield 9 and the aluminum shield 6 are electrically connected to each other due to the integrated cable structure. By using as a ground, it is possible to suppress noise (crosstalk, reflection) that intrudes into the cable from the outside and noise (crosstalk, reflection) that intrudes from the adjacent wire 5. Therefore, all the aluminum shielded wires 8 can be used as the signal lines 15. Further, when fitting with the connector 19, the aluminum shield 6 is peeled off only at the portion where the bare wire 8 with the aluminum shield is fitted, and the contact 21 inside the connector 19 is removed.
Press against.

Further, by interposing a plurality of drain wires 12 between the aluminum shielded strands 8, it is possible to press the drain wires 12 to the terminals 13 instead of the braided shield 9 so that they are collectively conducted. Is.

[0018]

According to the present invention, noise (crosstalk, reflection) that intrudes into the cable from the outside and noise (crosstalk, reflection) that intrudes from the adjacent wire can be suppressed, and the wire with aluminum shield can be suppressed. Can be used as signal lines, which leads to a reduction in the number of cables. Further, since the processing (wiring) of the ground line is unnecessary, the throughput is improved and the work man-hour can be reduced. Comparing the manufacturing costs, the processing cost can be reduced by 85% compared to the conventional method.

Therefore, the CPU (central processing unit) and PI /
The cost of cables between control devices such as interfaces between O (process input / output devices) can be significantly reduced.

[Brief description of drawings]

FIG. 1 is an external view showing one embodiment of a multi-core shielded cable of the present invention.

FIG. 2 is a sectional view of the multi-core shielded cable of the present invention shown in FIG.

FIG. 3 is a diagram showing a wiring system of the multi-core shielded cable of the present invention.

FIG. 4 is a cross-sectional view showing a conventional multi-core cable (twisted wire).

FIG. 5 is a diagram showing a conventional multi-core cable (twist wire) connection method.

[Explanation of symbols]

1 ... Conductor, 3 ... Insulator, 5 ... Elemental wire, 6 ... Aluminum shield, 7 ... Twisted wire, 8 ... Aluminum shielded elemental wire, 9
... Braided shield, 11 ... Outer skin, 13 ... Terminal, 15 ... Signal line, 17 ... Ground line, 19 ... Connector, 21 ... Contact.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Takamatsu 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Co., Ltd. Omika Factory, Hitachi Ltd. No. 1 Incorporated company Hitachi Ltd. Omika factory (72) Inventor Akiyo Nihira 52-1 Omika-cho, Hitachi city, Ibaraki prefecture Incorporated company Hitachi Ltd. Omika factory (72) Inventor Yoshiteru Kimura Omika Hitachi city, Ibaraki prefecture 5-2-1 machi, Hitachi Ltd. Omika factory (72) Inventor Hiroshi Aida 5-2-1 Omika-cho, Hitachi city, Ibaraki Hitachi Ltd. Omika factory

Claims (3)

[Claims] 1. A cable element wire comprising a core wire as a conductor, an insulator covering the core wire, and a conductive first shielding layer covering the outer periphery of the insulator, and the cable element. It is composed of a circular second shielding layer for accommodating a plurality of wires in a free space inside thereof, and an outer covering for covering the outer periphery of the second shielding layer, and the plurality of cable strands are in contact with each other. , Arranged in the free space so as to come into direct or indirect contact with the second shielding layer, and the first shielding layers of all the cable strands are electrically connected to the second shielding layer. A shielded multi-core cable that is characterized by 2. The shielded multicore cable according to claim 1, wherein the first shielding layer is an aluminum shield. 3. The shielded multi-core cable according to claim 1, wherein the second shielding layer is a braided shield.