JP2003242840A - Shielded cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shielded cable assuring stable electric contact between a shielding layer and a drain wire even when the size of a signal wire conductor is the same as that of the drain wire and allowing the supply of good signals. <P>SOLUTION: The shielded cable 11 comprises a plurality of signal wires 12 with insulating covers and the drain wire 13 encased therein, the peripheries of which are covered with the shielding layer 14 and an insulating sheath 15 in sequence. The stranding pitch of the drain wire 13 is differentiated from the standing pitches of the plurality of signal wires 12 with insulating covers. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielded cable, and more particularly to a shielded cable suitable for electrical connection to electric components of vehicles such as automobiles.

[0002]

2. Description of the Related Art In vehicles such as automobiles, shielded cables are used for electrical connection to various electric components. The structure of a conventional shielded cable is shown in FIG. As shown in these figures, the conventional shielded cable 1 has 2
In general, a structure in which a signal wire 2 with an insulating coating and a drain wire 3 are twisted together is covered with a shield layer 4, and the periphery thereof is further covered with an insulating sheath 5.

In such a structure, external noise is shielded by the shield layer 4, and the shielded noise is dropped to the external earth through the drain wire 3. Good signals are supplied to the various electric components via the signal line 2.

However, in the shielded cable 1 having such a structure, the signal line 2 and the drain line 3 are twisted at the same pitch. Therefore, if the signal line conductor and the drain wire have the same size, a gap between the signal lines 2 is formed. The drain wire fell into the shield layer 4 and the drain wire 3
The electrical contact with the instability became unstable, and it sometimes hindered the supply of a good signal. Therefore, it is necessary to use a drain wire having a diameter larger than that of the signal line conductor. In that case, depending on the sizes of the signal line conductor and the drain wire, it is necessary to divide the size of the connection terminal to be connected to the end of the cable, which causes a difficulty in workability of terminal connection.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. Even if the signal line conductor and the drain wire have the same size, the electrical connection between the shield layer and the drain line is not achieved. Stable contact can be secured,
It is an object of the present invention to provide a shielded cable capable of supplying a good signal.

[0006]

According to the present invention, the following technical means are provided in order to solve the above problems. (1) In a shielded cable including a plurality of signal wires with insulation coating and a drain wire, and surrounding them in order by a shield layer and an insulating sheath, in a twisted pitch of the drain wires A shielded cable characterized in that the twisted pitch of the attached signal line is different. (2) The shielded cable according to (1), wherein the twist pitch of the drain wire is an integer multiple of the twist pitch of the plurality of signal wires with insulation coating. (3) The diameter of the drain wire and the diameter of the conductor of the signal wire with insulation coating are the same, (1) or (2)
Shielded cable described in.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to preferred examples. FIG. 2 shows the structure of a shielded cable according to an embodiment of the present invention. FIG. 2A is a cross-sectional view of the shielded cable, and FIG. 2B is a diagram showing a state in which two insulation-coated signal lines and drain lines are twisted together. As shown in these figures, the shielded cable 11 of the present embodiment has a shield layer 14 covering the circumference of a twisted signal wire 12 with an insulating coating and a drain wire 13, and further insulating the surrounding area. Although the structure is covered with the flexible sheath 15, the twist pitch of the drain wire 13 is different from the twist pitch of the two signal wires 12 with insulation coating. In this embodiment, the twist pitch of the drain wires 13 is twice the twist pitch of the two signal wires 12 with insulation coating. The signal line 12 is composed of a conductor 12a and an insulating coating 12b. Although the present embodiment shows the simplest structure for simplification of the description, the number of signal lines 12 with insulation coating is
It is possible to set an appropriate number of three or more depending on the application. In addition, in the present embodiment, the twist pitch of the drain wire 13 is set to be twice the twist pitch of the signal wire 12 with insulation coating, but if both twist pitches are different, the intended purpose of the present invention is Can be achieved. If the double-twisted pitches are in an integral multiple relationship, there is an advantage that the untwisting work during terminal processing becomes easy. Further, in order to make the twisted pitch of the insulation-coated signal wire 12 and the twisted pitch of the drain wire 13 different from each other, both wires may be twisted at the same time. The drain wire 13 may be twisted and the drain wire 13 may be twisted later. Furthermore, if the twisting direction of the insulation-coated signal wire 12 and the twisting direction of the drain wire 13 are the same, there is also an advantage that the untwisting operation at the time of terminal processing becomes easy.

As the conductor 12a of the signal line 12, an annealed copper twisted wire (including a compressed twisted wire), an annealed copper single core wire, a tin-plated annealed copper twisted wire and the like can be used. The cross-sectional area of the conductor 12a of the signal line 12 (hereinafter, also referred to as conductor size) is 0.05 to 2 m.
It is about m ² . As the insulating coating 12b of the signal line 12, various resin materials such as polyvinyl chloride (PVC) and foamed polyethylene which have been conventionally used can be used. The thickness of the insulating coating 12b of the signal line is appropriately set according to the conductor size of the conductor 12a (the signal line 12 is according to the standard).
Because the outer diameter of is determined).

The drain wire 13 is made of a material such as a soft conductive wire and a Sn-plated soft conductive wire. The conductor size of the drain line 13 is about 0.05 to ² mm ² , and the conductor size of the signal line 12 is 1.
It may be the same as the conductor size of 2a, but may be different. If both conductor sizes are the same, there is an advantage that the same connecting terminal size can be used.

A material having a shielding effect is used for the shield layer 14, and specifically, Sn-plated copper foil PET tape, Sn-plated copper foil / PET tape, aluminum PE.
T tape or the like can be used, and the thickness thereof is about 10 to 30 μm.

The insulating sheath 15 has an insulating property, oil resistance,
A material having chemical resistance is used, and specifically, an insulating material such as polyvinyl chloride or polyolefin resin such as polyethylene can be used, and the thickness thereof is about 0.3 mm.

With the above structure, the drain wire 13 continues to fall into the gap between the insulation-coated signal wires 12,
It is prevented that the contact between the drain wire 13 and the shield layer 14 is lost. Further, the conductor size of the drain line 13 does not have to be increased in order to prevent the drop, and the signal line 12
It is possible to use a conductor having the same conductor size as the conductor 12a. In that case, since it is not necessary to divide the size of the connection terminal, the terminal connection work can be efficiently performed.

An example of the shielded cable according to the present invention is shown in Table 1 in comparison with the conventional one.

[Table 1]

The double twist pitch of the product of the present invention in Table 1 means that the twist pitch of the drain wire is twice the twist pitch of the signal wire as shown in FIG. When the signal characteristics of the shielded cable having the above-described size were examined, it was found that good signal characteristics could be obtained according to the product of the present invention, although the conductor size of the drain wire was reduced.

[0015]

According to the present invention, since the above-mentioned configuration is adopted, it is possible to prevent the drain line from continuously falling into the gap between the signal lines and the electrical contact between the drain line and the shield layer being lost, and the signal line conductor. Even if the sizes of the drain wire and the drain wire are the same, electrical contact between the shield layer and the drain wire can be stably ensured, and a good signal can be supplied.

[Brief description of drawings]

1A is a cross-sectional view showing the structure of a conventional shielded cable, and FIG. 1B is a view showing a twisted state of a signal wire with an insulation coating and a drain wire.

2A is a cross-sectional view showing the structure of a shielded cable according to an embodiment of the present invention, and FIG. 2B is a view showing a twisted state of a signal wire with an insulation coating and a drain wire.

[Explanation of symbols]

11 shielded cable 12 Signal line with insulation coating 12a conductor 12b insulation coating 13 drain wire 14 Shield layer 15 Insulating sheath

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanobu Yoshimura             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. (72) Inventor Kenji Ikeda             Sumitomo Den 1-14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie Prefecture             Sozo Co., Ltd. F-term (reference) 5G313 AA10 AB05 AC11 AD08

Claims (3)

[Claims] 1. A shielded cable comprising a plurality of signal wires with insulation coating and a drain wire, which are sequentially covered with a shield layer and an insulating sheath around the twisted pitch of the drain wires. A shielded cable characterized by having a twisted pitch different from that of the signal wire with insulation coating. 2. The shielded cable according to claim 1, wherein the twist pitch of the drain wire is an integral multiple of the twist pitch of the plurality of signal wires with insulation coating. 3. The shielded cable according to claim 1, wherein the diameter of the drain wire and the diameter of the conductor of the signal wire with insulation coating are the same.