JP2005197036A - Shield cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield cable for an automobile which is excellent in bending performance and advantageous in wiring in the portion where vibration and bending force are frequently applied, and is superior in shield characteristics. <P>SOLUTION: In the shield cable which contains one or a plurality of signal lines with insulating coating and in which the surroundings of these are covered by a shield layer and an insulating sheath in the order, the shield layer is made of a braid structure using strands made of Cu-Sn alloy (Sn 0.2-0.3%, and the remainder Cu (weight reference)). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a shielded cable used for electrical connection to an electrical component of a vehicle such as an automobile.

  In automobiles, shielded cables are used for electrical connection to electrical components and the like. In particular, with the increase of in-vehicle multimedia such as in-vehicle cameras and car navigation systems, the amount of use is increasing. The shielded cable has a structure in which a shield layer is provided for the purpose of making it difficult to receive noise from the outside and making it difficult for noise generated by itself to be made to the outside.

Two examples of conventional shielded cables are shown in FIGS.
First, the example of FIG. 1A will be described. In the figure, reference numeral 11 denotes a shielded cable, which includes a single signal wire 12 with insulation coating and a drain wire 13, and these are covered with a shield layer 14. Further, the periphery thereof is covered with an insulating sheath 15. The signal line 12 includes a conducting wire 12a and an insulating coating 12b. For the shield layer 14, a metal foil tape such as a PET tape with a copper foil or a PET tape with an aluminum foil is usually used because it is inexpensive and has good terminal processability.

  Next, the example of FIG. 1B will be described. In the figure, reference numeral 21 denotes a shielded cable, which includes a plurality of (seven in this example) signal wires 22 with insulation coating and drain wires 23, The periphery is covered with a shield layer 24, and the periphery thereof is covered with an insulating sheath 25. The signal line 22 includes a conducting wire 22a and an insulating coating 22b. Similarly to the above, for the shield layer 14, a metal foil tape such as a PET tape with a copper foil or a PET tape with an aluminum foil is usually used because of its low cost and good terminal processability.

On the other hand, in recent automobiles, the amount of shielded cable that is routed to a part that receives a lot of vibration or a part that receives a lot of bending is increasing. If vibration or bending force is frequently applied in such a part, the shield layer (metal foil) may be broken, and the conventional structure has sufficient flexibility (for example, 60,000 door bending tests (see FIG. 2). It cannot be said that the shield layer is not torn). For example, when a door bending test (as shown in FIG. 2) is performed on a conductor having a conductor size of 0.3 mm ² in three cores, a shield layer (metal foil) is formed by 60,000 door bendings. The required high bending performance (required value: no tearing after 60,000 times) was not achieved.

  The present invention provides a shielded cable for automobiles that solves the problems of the prior art, has excellent flexibility, is advantageous for wiring to sites where vibration and bending force are frequently applied, and has excellent shielding characteristics. The task is to do.

According to the present invention, the above problem is solved by the following technical means.
(1) In a shielded cable including one or a plurality of signal wires with insulation coating and sequentially covering the periphery with a shield layer and an insulating sheath, the shield layer is formed of a Cu—Sn alloy (Sn0. A shielded cable characterized by having a braided structure using a strand composed of 2 to 0.3%, balance Cu: (weight basis).
(2) The shielded cable according to (1), wherein a drain wire is included together with the signal wire with insulation coating.
(3) The shielded cable according to (1) or (2), wherein a strand having a diameter of 0.08 to 0.16 mmφ is used as the braided strand.

  According to the present invention, since the above-described configuration is adopted, it is possible to provide a shielded cable for an automobile that has excellent flexibility and is advantageous in wiring to a site where vibration and bending force are frequently applied and has excellent flexibility. It becomes possible.

  The preferred embodiments of the present invention will be described below.

  In order to achieve high flexibility that cannot be achieved with a conventional automotive shield cable having a shield layer using a metal foil such as a copper foil or an aluminum foil, the present inventor has various aspects in terms of the material and form of the shield layer. As a result of the examination, a copper alloy having a specific composition made of a specific material is used for the shield layer, and its shape is set to a braided configuration, so that the required value for the flexibility (the value of the shield layer is 60,000 times in the door bending test). It has been confirmed that satisfactory shielding properties can be secured, and the present invention has been completed.

  The shielded cable according to the present invention includes one or a plurality of signal wires with insulation coating, and a shield cable in which the periphery thereof is sequentially covered with a shield layer and an insulating sheath. It is characterized by having a braided structure using a strand made of an alloy (Sn 0.2-0.3%, balance Cu: (weight basis (hereinafter the same)).

FIGS. 3A and 3B schematically show two examples of the structure of the shielded cable according to the present invention in cross-sectional views.
In the structural example of FIG. 3A, 31 is a shielded cable, which includes a single signal wire 32 with insulation coating and a drain wire 33, which is covered with a shield layer 34, and further around that. It is configured by covering with an insulating sheath 35. The signal line 32 includes a conducting wire 32a and an insulating coating 32b. The shielded cable 31 of this example has a braided structure using a copper alloy having the above composition with the shield layer 34 as a strand.

  In the structural example of FIG. 3B, reference numeral 41 denotes a shielded cable, which includes a plurality (seven in this example) of the insulation-coated signal lines 42 and the drain lines 43, and a shield layer 44 around them. It is configured by covering and further surrounding with an insulating sheath 45. Each signal line 42 is composed of a conducting wire 42a and its insulating coating 42b. The shielded cable 41 of this example also has a braided configuration using a copper alloy having a specific composition with the shield layer 44 as a strand.

In the shielded cable of the present invention, a Cu—Sn alloy that has excellent shielding characteristics and is resistant to bending is used as the strand of the braided structure of the shield layer. The composition of Sn in the Cu—Sn alloy used in the present invention is 0.2 to 0.3% by weight (hereinafter the same). And the remainder is Cu. If the Sn content is less than the above, the required value for flexibility cannot be satisfied, and if the Sn content is more than the above, it is difficult to ensure good shielding properties.
The diameter of the wire can be set to an appropriate value depending on the application, the size of the electric wire, etc., but when a braided structure is used using a small diameter of 0.08 to 0.16 mmφ, Flexibility can be further improved.
In the braided structure of the shield layer, it is preferable to incorporate a plurality of the above-mentioned strands, for example, about 6 to 8 wires, in a grid pattern, for example, about 16 to 36 strokes.

表１より、本発明で用いるＣｕ−Ｓｎ合金は純銅より屈曲に強い材料であることがわかる。 Here, the bendability of the wire using the Cu—Sn alloy will be described in comparison with the wire using Cu.
First, bending strain was compared between a strand made of a copper alloy (Cu—Sn; Sn 0.3%) used in the present invention and a conventional strand made of pure copper. The comparison was made by fixing a strand with a diameter of 0.5 mmφ and bending it many times with a compressible / tensible testing machine, with a strain of 0.4% upward and 0.3% downward. The number of bendings that occurred was determined. FIG. 4 shows the state of the test. The results are shown in Table 1.

From Table 1, it can be seen that the Cu—Sn alloy used in the present invention is a material that is more resistant to bending than pure copper.

FIGS. 5 to 8 show the effects on the tensile strength, the number of bending breaks, the electrical conductivity, and the conductor resistance of Sn contained in the copper alloy used in the present invention in comparison with pure copper.
From these figures, (1) the greater the Sn content, the greater the tensile strength, (2) the greater the Sn content, the greater the number of flex breaks, and (3) the greater Sn content. It can be seen that the conductivity becomes worse, and (4) the higher the Sn content is, the worse the conductor resistance becomes (the shielding property becomes worse).
From these data, it is understood that if the Sn content in the copper alloy used in the present invention is set within the above range, high flexibility can be realized while maintaining good shielding properties.

In the shielded cable of the present invention, as the conductive wire in the signal wire with insulation coating, an annealed copper stranded wire (including a compression wire), an annealed copper single core wire, an Sn plated annealed copper stranded wire, an aluminum stranded wire, or the like can be used.
As the signal line insulation coating, resin materials such as polyvinyl chloride, polyethylene (cross-linked, non-cross-linked), halogen-free materials, etc. are generally used.
The diameter dimensions of the signal line and the conducting wire can be set to appropriate values according to the use, the wiring site, and the like.

  In the shielded cable of the present invention, the drain line may or may not be provided, but when provided, the same material as that used for the signal line can be used.

  In the shielded cable of the present invention, a resin material such as polyvinyl chloride, polyethylene (cross-linked or non-cross-linked), polyester (cross-linked or non-cross-linked) or halogen-free material is generally used as the insulating sheath.

Next, a production example of a shielded cable for automobiles according to the present invention is shown in comparison with a conventional example.
The shielded cable of the present invention is composed of three signal wires (conductor material: annealed copper, insulating material: halogen-free material) having a conductor size of 0.3 mm ^{2 and} a Cu-Sn alloy (Sn 0.3%) as a shield layer. The insulation sheath used was made of a halogen-free material and had a thickness of 0.5 mm. As the braided configuration, 16 braided pieces of 8 strands made of a Cu—Sn alloy having a diameter of 0.08 mmφ were used.
The conventional example of the shielded cable, conductor size 0.3 mm ² of the signal line (conductive material: annealed copper, insulating material: PVC) 3 present, and using a PET tape with Cu foil (thickness 15 [mu] m) as the shield layer, as an insulating sheath Is made of PVC and has a thickness of 0.5 mm.
In addition, the shielded cable of the reference example has a braided configuration using three signal wires (conductor material: annealed copper, insulating material: halogen-free material) having a conductor size of 0.3 mm ^{2 and} a strand made of Sn-plated annealed copper as the shield layer. An insulating sheath made of a halogen-free material and having a thickness of 0.5 mm was used. As the braided configuration, 16 strands of 6 strands made of Sn-plated annealed copper having a diameter of 0.12 mmφ were used.
The door bending test shown in FIG. 2 was performed on each shielded cable produced above. As a result, the metal foil was broken after the door was bent 60,000 times. The wire of the present invention was not broken even after the door was bent 60,000 times. In the reference example, one or two strands were cut by 60,000 door bendings.
From these results, the superiority of the shielded cable according to the present invention was confirmed.

It is sectional drawing which shows the structure of the conventional shielded cable typically. It is explanatory drawing of a door bending test. It is sectional drawing which shows the structure of the shielded cable by this invention typically. It is explanatory drawing of the test which investigates the relationship between a bending distortion and the frequency | count of bending. It is a figure which shows the influence on tensile strength by containing Sn in the copper alloy used by this invention compared with pure copper. It is a figure which shows the influence on the frequency | count of bending disconnection by containing Sn in the copper alloy used by this invention compared with pure copper. It is a figure which shows the influence on the electrical conductivity by containing Sn in the copper alloy used by this invention compared with pure copper. It is a figure which shows the influence on conductor resistance by containing Sn in the copper alloy used by this invention compared with pure copper.

Explanation of symbols

31, 41 Shielded cable 32, 42 Signal wire with insulation coating 32a, 42a Conductor wire 32b, 42b Insulation coating 33a, 43a Drain wire 34a, 44a Shield layer (braided configuration)
35, 45 Insulating sheath

Claims (3)

  In a shielded cable including one or a plurality of signal lines with insulation coating and sequentially covering the periphery of the signal lines with a shield layer and an insulating sheath, the shield layer is made of a Cu—Sn alloy (Sn 0.2 to 0). . 3%, balance Cu: (weight basis)) Shielded cable characterized by having a braided structure using a strand.   The shielded cable according to claim 1, wherein a drain wire is included together with the signal wire with insulation coating.   The shielded cable according to claim 1 or 2, wherein a strand having a diameter of 0.08 to 0.16 mmφ is used as the braided strand.

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