JP2594619Y2 - Shielded cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a shielded cable having excellent bending characteristics and particularly suitable for use in a movable portion.

[Conventional technology]

In a conventional shielded cable, as a shield layer, for example, a copper round wire is braided or horizontally wound as shown in Japanese Utility Model Laid-Open No. 2-27608, or
As described in -146913 and the like, a thin copper or aluminum tape is generally attached vertically or horizontally to the outer periphery of the cable core.

[Problems to be solved by the invention]

As described above, a shielded cable using a copper wire or a metal foil tape as the shield element wire has a certain degree of flexibility, but the bending resistance and the restoring resistance are increased due to the presence of the shield layer. For this reason, for example, when this is processed into a coil to form a coil cable, the former shielded cable made of copper braid has a problem in durability of the shielded wire against repeated expansion and contraction. Also, in the latter cable, although the durability of the shield layer itself is high, its flexibility is not so good, and there is a problem that the entire cable has poor stretchability. It is not always sufficient for use in a movable part which receives an external force such as repeated twisting.

In view of these problems of the related art, an object of the present invention is to provide a shielded cable having good bending characteristics and suitable for use in a movable portion.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, a cable core formed of at least one insulated core is
In a shielded cable in which a conductive wire is braided or horizontally wound as a shield layer, the wire is formed by forming at least two individual conductive wires around a flexible core having tensile strength in opposite directions. It is characterized by being spirally wound so as to intersect.

[Action]

In the shielded cable according to the present invention, the wire forming the shield layer is made of a conductive wire around a small-diameter core made of a synthetic fiber thread having tensile strength and flexibility such as polyester fiber. Since it is a configuration in which at least two individual metal foils such as copper foils are helically wound with a small diameter so as to cross in opposite directions to each other as a strip,
When subjected to an external force such as bending, the inner flexible core deforms naturally while allowing deformation and distortion of the spiral conductive filaments crossing in opposite directions. For this reason,
Compared to conventional shielded wires such as copper wires and metal foils, they exhibit much better flexibility and have lower bending resistance and restoration resistance. At this time, since the shield wire is spirally wound around the core with at least two individual conductive wires crossing each other in opposite directions, the shield wire is: While maintaining the flexibility, while exhibiting the appropriate shape maintenance of the conductive wire, the twisting habit of right and left winding of the conductive wire can be offset, and the twisting habit of the shield wire itself can be reduced. It is possible to prevent scatter, and the handling becomes extremely easy, and the workability is improved. Further, even when the shield wire is twisted when the cable is bent or when the shield layer is formed, the shield wire in the present invention has the conductive wire of any layer in the opposite direction to the core. Since the body is tightened, the shield strand itself is difficult to disperse structurally, preventing the occurrence of gaps due to the displacement of the conductive wire, ensuring that the conductive wire exists around the core, and thus the shielding effect Is well secured against bending.

Furthermore, since the core has a high tensile strength and a small elongation in the longitudinal direction of the whole shield wire, the internal strain generated in the shield wire itself due to bending is small, and the bending resistance is stronger than the round wire or foil. Therefore, the bending life is long. Therefore, in the shielded cable of the present invention using such a shielded wire, since the shield layer itself has good flexibility, the repetition resistance and the like of the entire cable are improved as compared with the conventional cable, and the cable is also bent. The service life is greatly extended. Also, when a coil cable is formed by performing coil processing, the shield layer is flexible and the influence on the expansion and contraction characteristics of the cable is smaller than that of the conventional cable, so that a cable excellent in spring property can be obtained.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the shielded cable according to the present invention. The illustrated shielded cable 1 has an insulated core wire 4 in which an insulator 3 is coated on the outer periphery of a stranded conductor 2 as a cable core, and a shield wire 10 shown in FIG. , And a shield layer 5 and a sheath 6 are provided. Here, as shown in detail in FIG. 2, the shield element wire 10 is made of a core body 11 made of a material having tensile strength and flexibility, for example, a twisted yarn of polyester fiber, and a conductive wire around the core body 11. At least two individually conductive metal foils 12a and 12b such as copper foils are spirally wound crossing each other in opposite directions (lower left and upper left in the figure).

In the figure, the conductive filament wound around the outer periphery of the core body 11 is illustrated as an example of a two-layer winding (12a, 12b), but may be formed of three or more layers. As for the winding method, the winding may be performed such that a slight gap is left as in the embodiment, or the winding may be performed. The thickness of the conductive wires 12a and 12b is generally
0.01 to 0.1 mm, width of about 0.2 to 2 mm copper foil and other metal foils with good conductivity, or those foils plated with silver, tin, nickel, etc., or metal deposited or laminated on plastic film A tape-shaped member or the like is suitably used without impairing the flexibility of the cable. When these are wound tightly or lap-wound, the flexibility and bending life of the shield wire are further improved, and this has a favorable effect on the entire cable. Further, the conductive filament is not necessarily limited to the metal foil tape, and a round thin wire or the like may be used.

Further, as the flexible core 11, in order to obtain necessary flexibility and tensile strength, for example, polyamide-based yarn, polyester-based yarn, fluororesin-based yarn subjected to a stretching treatment, and other various synthetic resin-made yarns A multi- or monofilament yarn, or a fine fiber, a natural fiber yarn such as a cotton yarn, a silk yarn, and a hemp yarn can be appropriately selected according to conditions.

As described above, in the shielded cable 1 according to the present invention, in which the shield layer 5 is made of the flexible wire 10, the flexibility of the shield layer 5, which greatly affects the flexibility of the entire cable, is high. As a result, it smoothly follows external forces such as bending and twisting, and the bending life is greatly improved.
Further, if the conductor of the insulated core wire has the same configuration as the shield wire, the bending characteristics and the expansion and contraction characteristics of the cable are further improved.

[Effect of the invention]

As described above, in the shielded cable according to the present invention, at least two separate conductive wires are formed around the flexible core having a tensile strength in such a manner that the shield layer has a great influence on the flexibility of the cable. The shield wire is formed by a shield wire that is spirally wound crosswise to the direction, so that the shield wire can be used for various external forces such as repeated bending, expansion and contraction, or twisting. Spiral-shaped helical wire with flexible cores of shield wires crossed in opposite directions without impairing the shielding effect by demonstrating the appropriate shape maintenance of the conductive wire while maintaining flexibility. An excellent effect is obtained in that the conductive filaments can be easily deformed and deformed while allowing them to flexibly follow and have excellent bending characteristics, and the bending life is greatly improved as compared with conventional ones. Therefore, it is particularly suitable for use on moving parts, and is convenient for use in the form of, for example, a coil cable.

In the above embodiment, an example of the coaxial cable structure in which the cable core is constituted by one insulated core wire has been described. However, the present invention may be applied to a multi-core cable having a plurality of the cable cores, and a braided shield. It is also possible to use a horizontal winding instead of the layer, and it is of course possible to make various modifications within the technical idea of the present invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the shielded cable according to the present invention, and FIG. 2 is a perspective view of a shield wire used in the embodiment shown in FIG. 4: Insulated core wire, 5: shield layer, 10: shield wire, 11: flexible core, 12a, 12b: conductive wire.

Claims (1)

(57) [Scope of request for utility model registration] 1. A shielded cable in which a conductive wire is braided or horizontally wound as a shield layer outside a cable core formed of at least one insulated core wire, wherein the wire has a tensile strength. A shielded cable, wherein at least two individual conductive wires are spirally wound around a flexible core so as to cross each other in opposite directions.