JPH0527774Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a shielded flat cable, and in particular to an improvement in the installation technique of its drain wire.

2. Description of the Related Art As is well known, a flat cable is a cable in which conductors are arranged in a flat shape and insulated.

This flat cable is often coated all around with a shielding material to prevent electromagnetic noise from occurring. Shielding materials include metal foil,
A metal mesh or the like is used, and in order to improve shielding properties, the shield may be coated with a metal foil and then further covered with a metal mesh.

A drain wire for taking earth from the shielding material coated around the flat cable is usually interposed between the flat cable and the shielding material.

After the flat cable is coated with a shielding material, a jacket made of polyvinyl chloride or the like can be further provided thereon to provide an insulating coating, if necessary.

Problems to be Solved by the Invention However, with the shielded flat cable having the above structure, the contact between the drain wire and the shielding material is poor, resulting in poor grounding, or the drain wire may fall out between the flat cable and the shielding material. This may lead to problems such as interference, and as a result, there is a risk that reliability in preventing electromagnetic noise may be impaired.

The object of the present invention is to provide a shielded flat cable that does not cause poor contact or disconnection of the drain wire.

Means for Solving the Problems The shielded flat cable of the present invention has a flat cable 1 wrapped in a resin-coated metal foil 2, and the resin-coated metal foil 2 in the enclosed state is placed on the side of the flat cable 1. With the metal foil portions of the resin-coated metal foil 2 above and below the overhanging portion 2a facing each other, a string-like string made of a metal braid or metal mesh is attached along the overhanging portion 2a. Drain wire 3
is installed by machine sewing with 4 threads.

The present invention will be explained in detail below.

As the flat cable 1, any flat cable having a structure in which conductors 1a are arranged in parallel within a planar insulator 1b can be used.

As the resin-coated metal foil 2 as a shielding material, a metal foil such as aluminum foil, copper foil, iron foil, or nickel foil coated with a resin such as polyolefin, polyester, or polyamide is used.
Resin coating is applied because the tensile strength of metal foil alone is
This is because tear strength is inferior.

The resin-coated metal foil 2 is arranged so that the resin-coated metal foil 2 slightly protrudes from the side edge of the flat cable 1 when the flat cable 1 is enclosed therein. This overhanging portion 2a is a resin-coated metal foil 2
If it is folded in half and the flat cable 1 is sandwiched between them, it will be formed on one side edge, and if the flat cable 1 is interposed between two sheets of resin-coated metal foil 2, both of them will be formed. It will be formed on the side edge of. The former mode is usually adopted.

In the present invention, the overhanging portion 2
The metal foil portions of the resin-coated metal foil 2 above and below a are arranged to face each other. Since the resin-coated metal foil 2 usually has its resin-coated surface on the inside, the upper and lower edge portions of the resin-coated metal foil 2 are folded back inward, and both folded portions are made to face each other.

With the metal foil portions of the upper and lower resin-coated metal foils 2 facing each other in this way, a string-like drain wire 3 made of a metal braid or metal mesh is sewn along the overhanging portion 2a with a thread 4. Installed by "Along the overhanging portion 2a" includes both the case where the drain wire 3 is placed on one side of the folded part and sewn, and the case where the drain wire 3 is interposed between the folded parts and sewn. However, the former mode is more practical.

As the thread 4, a normal thread or a thread made of conductive fiber is used.

As a result, the desired shielded flat cable can be obtained. If necessary, a cylindrical metal mesh or the like as a second shielding material may be further included from the outside to ensure the completeness of the shield.

Further, after the flat cable 1 is coated with a shielding material, a jacket made of polyvinyl chloride or the like may be further provided thereon to provide an insulating coating, if necessary.

Function In the shielded flat cable of the present invention, the coated metal foil 2 as a shielding material encloses the flat cable 1, and the coated metal foil 2
Since the upper and lower metal foil portions of the flat cable 1 are sealed off at the overhanging portion 2a, the flat cable 1 is completely wrapped in the covering metal foil 2.

In addition, since a string-like drain wire 3 made of a metal braid or metal mesh is fixed by sewing along the overhanging portion 2a of the coated metal foil 2, complete grounding is achieved.

Therefore, the covering metal foil 2 and the drain wire 3 fixed thereto can completely prevent electromagnetic noise from occurring.

Example Next, the present invention will be further explained with reference to Examples.

Embodiment 1 Figures 1 and 2 are cross-sectional end views showing an example of the flat cable of the present invention. Figure 1 shows the state before the drain wire 3 is sewn, and Figure 2 shows the state after the drain wire 3 has been sewn. It indicates the condition.

1 is a flat cable with a width of 43 mm, and has a structure in which conductors 1a are arranged in parallel within a flat insulator 1b.

2 is a coated metal foil as a shielding material;
Consists of polyester laminated aluminum foil (inner polyester layer) with a width of 120 mm when unfolded.

This coated metal foil 2 is folded in two and the flat cable 1 is interposed between them. The 5 mm width portions at both ends of the overhanging portion 2a of the coated metal foil 2 are bent inward on both the upper and lower sides so that the upper and lower folded surfaces (metal foil surfaces) are opposed to and in contact with each other.

3 is a string-like drain wire with a folding width of 4 mm, which is obtained by flattening a metal braid obtained by braiding tin-plated copper wire, and a thread 4 made of nylon monofilament.
It is sewn along the overhanging portion 2a by machine sewing using a sewing machine.

Although it is not shown in the diagram, drain wire 3
One end of the flat cable 1 extends beyond the end of the flat cable 1 for grounding.

The electromagnetic wave shielding properties of the shielded flat cable having the above structure were extremely favorable.

Embodiment 2 FIG. 3 is a sectional end view showing another example of the flat cable of the present invention.

In this embodiment, as the drain wire 3, a string-like wire having a fold width of 4 mm was used, which was obtained by flattening a metal mesh obtained by knitting tin-plated copper wire into a cylindrical shape.

As in Example 1, the covering metal foil 2 is made of polyester laminated aluminum foil, which is folded in two and the flat cable 1 is interposed between them.

A 5 mm wide portion at both ends of the overhanging portion 2a of the coated metal foil 2 is bent inward, and the above-mentioned drain wire 3 is placed between the upper and lower bent portions (metal foil surface), It is sewn along the overhanging portion 2a with polyester monofilament thread 4.

Effects of the Invention In the shielded flat cable of the present invention, the flat cable 1 is completely wrapped in the coated metal foil 2 as a shielding material, and is sewn along the overhanging portion 2a of the coated metal foil 2. Since the drain wire 3 is also completely grounded, electromagnetic noise generation can be completely prevented. Therefore, the reliability of the cable is high.

The work of wrapping the flat cable 1 with the coated metal foil 2 and the work of installing the drain wire 3 are easy, and there is no problem in terms of productivity.

Furthermore, when the overhanging portions 2a of the resin-coated metal foil 2 are bent inward to face each other, the thickness of each portion is doubled and reinforced. Even if the drain wire 3 is applied and sewing is performed using the thread 4, there is no fear that the strength of the part will be reduced due to the perforation hole.

Therefore, the present invention greatly contributes to the industry that deals with shielded flat cables.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional end views showing an example of the flat cable of the present invention. Figure 1 shows the state before the drain wire 3 is sewn, and Figure 2 shows the state after the drain wire 3 is sewn. It is something. FIG. 3 is a sectional end view showing another example of the flat cable of the present invention. 1...Flat cable, 1a...Conductor, 1b
... Insulator, 2 ... Covering metal foil, 2a ... Overhanging portion, 3 ... Drain wire, 4 ... Thread.

Claims (1)

[Scope of utility model registration request] The flat cable 1 is enclosed in the resin-coated metal foil 2, and the enclosed resin-coated metal foil 2 is made to slightly overhang the side edge of the flat cable 1, and the resin coating is applied above and below the overhanging portion 2a. A shielded flat cable in which a string-like drain wire 3 made of a metal braid or metal mesh is installed by machine sewing with a thread 4 along the overhanging portion 2a with the metal foil portions of the metal foil 2 facing each other. .