JPS6039945Y2 - shielded wire - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a flat shielded electric wire.

Conventionally, shielded wires have been used for wiring electrical equipment such as audio and wireless equipment.

In order to improve the workability during wiring, shielded wires with a flat shape were developed.
In the techniques disclosed in Japanese Publication No. 1938-1938 and Japanese Utility Model Publication No. 55-52751, a braided shield is provided on a flat insulated conductor.

However, with a braided shield structure, it is difficult to strip the shielded wires, which causes a problem in that workability for grounding the shield layer, wiring conductors, etc. deteriorates.

As a way to solve this problem, the applicant proposed
No. 6-47991 proposed a shielded wire as shown in FIG.

In this technique, a plurality of insulated conductors 1 and drain wires 2 having parallel intervals are integrally covered with conductive plastic to form a shield layer 3, and a connecting piece 4 is formed to connect each shield layer 3. Furthermore, these are covered with a sheath 5.

This technological improvement improves the workability of stripping each core wire.
It was also possible to increase the flexibility of the entire wire.

On the other hand, in the shielded wire shown in FIG.
When forming a conductive plastic, conductive plastic is extruded onto the insulated conductor 1 and drain wire 2 using an extruder. If they are equal, the inner diameters of the dies of the extruder are equal and common, and specification changes such as changes in the position and number of drain wires 2 can be made arbitrarily.

Therefore, by setting the extruder die inner diameter to the same size,
The shield layer 3 around each insulated conductor 1 and the shield layer 3 around the drain wire 2 have the same outer diameter, and the drain wire 2 is made of the same conductive plastic as the shield layer 3 or other conductive material. A conceivable structure is to fill a conductive filler such as a compound and electrically connect the drain wire 2 and the shield layer 3 with the conductive filler 6, but in this structure, the conductive filler (
For example, conductive polyvinyl chloride) 6 is very expensive compared to the insulation coating of the insulated conductor 1 and the material of the sheath 5 (for example, polyethylene, polyvinyl chloride, etc.).
If the amount of material used for the conductive filler 6 increases, economic efficiency will be impaired.

This idea was made in consideration of the above background, and an insulated conductor with a notched groove reaching the conductor is used as a drain wire together with other insulated conductors, and a shield layer is placed on top of each of these insulated conductors. The object of the present invention is to provide a shielded wire that can be covered with a conductive material and filled with a conductive material in the notched groove, thereby making it easy to change the specifications of the shielded wire and suppressing increases in manufacturing costs.

This invention will be explained below based on embodiments shown in the drawings.

Fig. 3 shows the first embodiment of this invention, in which the shielded wire has a flat shape as a whole, and a plurality of insulated conductors 1, 1, etc. are arranged parallel to each other at equal intervals. A notched groove 10 reaching the conductor 1a is formed in the insulation coating 1b of at least one of the insulation coating conductors 1, and a conductive plastic is extruded onto each of the insulation coating conductors 1 to form a shield layer 3. It has a structure in which a sheath 5 is applied thereon.

Therefore, the notched groove 1c is filled with a conductive filler 6, and the conductor 1a and the shield layer 3 are electrically connected.

In the first embodiment, a conductive plastic having a specific resistivity of 2 to 3 Ω-cm is used as the constituent material of the shield layer 3 and the conductive filler 6 to form the conductor 1a.

Although the shield layer 3 and the connecting piece 4 are electrically connected to each other, a certain degree of variation in resistivity is allowed, and the conductive compound described above may be used as the conductive filler 6.

FIG. 4 shows a second embodiment of this invention, in which molten plastic is extruded onto a plurality of conductors 1a, which are spaced apart from each other, to form a common insulation coating 1b, and drain wires 2 A notched groove 1c is formed in the insulating coating 1b covering the desired conductor 1a, and the conductive filler 6 filled in the notched groove 1c forms a shield layer 3 made of copper foil or the like disposed on one side of the insulating coating 1b. , conductor 1
It is designed to conduct with a.

In this second embodiment, the shield layer 3 may be provided on both sides of the insulating coating 1b, and the sheath 5 may be formed on the shield layer 3.

In the shielded wire constructed in this way, each conductor 1a is surrounded and shielded by the shield layer 3, and is also covered with the insulating coating 1b or the conductive filler 6, making the peeling work easy. It can be implemented.

Furthermore, since the notched groove 1c formed in the insulating coating 1a is filled with the conductive filler 6, the amount of the conductive filler 6 used can be reduced, which is highly economical, and the number and position of the drain wires 2 can be set arbitrarily. This has the effect of increasing adaptability to changes in specifications.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the shielded wire proposed by the applicant earlier.
FIG. 2 is an explanatory diagram of a modification of FIG. 1, FIG. 3 is a cross-sectional view showing a first embodiment of this invention, and FIG. 4 is a cross-sectional view showing a second embodiment of this invention. 1...Insulated conductor, 1a...Conductor,
1b...Insulation coating, 1c...Notch groove,
2... Drain wire, 3... Shield layer, 5... Sheath, 6... Conductive filler.

Claims (1)

[Scope of utility model registration request] In a shielded wire in which a plurality of conductors 1a are arranged parallel to each other at intervals, and a shield layer 3 is integrally provided on an insulating sheath 1b covering these conductors, the insulating sheath of at least one of the conductors is A shielded electric wire characterized in that a notch i1c is formed to communicate the conductor and the shield layer, and the notch groove is filled with a conductive filler 6.