JP2019175789A - Shield cable - Google Patents

Abstract

To provide a shield cable maintaining shielding characteristics even when repeatedly bent.SOLUTION: A plurality of electric wires 3 are housed in a shield cable. Press winding 5 is provided around the outer periphery of the plurality of electric wires 3. A resin tape is wound to form the press winding 5. A tape-like member 8a is wound around the outer periphery of the press winding 5. The tape-like member 8a has electrical conductivity. The tape-like member 8a constitutes a shielding layer 7a as a first shielding layer. A shielding layer 7b as a second shielding layer is provided around the outer periphery of the shielding layer 7a. A shielding layer 7b is formed by laterally winding a plurality of metal wires 8b. A shielding layer 7c as a third shielding layer is provided around the outer periphery of the shielding layer 7b. The shielding layer 7c is formed by laterally winding a plurality of metal wires 8c. A sheath 9 is provided around the outer periphery of the shielding layer 7c. The sheath 9 is made of resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shielded cable used for an automobile, for example.

  Conventionally, a shielded cable is sometimes used for a cable used for a wire harness of an automobile in order to suppress the influence of noise generated from the cable on the outside and the influence of noise from the outside on the cable.

  As such a shielded cable, for example, a shielded cable having a first horizontally wound shield layer, a buffer layer provided on the outer periphery thereof, and a second horizontally wound shield layer provided on the outer periphery thereof has been proposed. (Patent Document 1).

JP 2007-311043 A

  However, in the shielded cable as in Patent Document 1, since each shield layer is divided in the radial direction via the buffer layer, when the shield cable is bent, there is a gap between the horizontal windings constituting each shield layer. This causes a problem that the shield characteristic is deteriorated.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a shielded cable that can maintain shielding characteristics even when the shielded cable is bent.

  In order to achieve the above-described object, the present invention provides an electric wire housed inside, a first shielding layer provided on an outer periphery of the electric wire, and an outer periphery of the first shielding layer. A second shielding layer that is in direct conduction with the shielding layer; a third shielding layer that is provided on the outer periphery of the second shielding layer and that is in direct conduction with the second shielding layer; and an outer circumference of the third shielding layer. And the first shielding layer is formed by winding a tape-like member having conductivity, and the second shielding layer and the third shielding layer are formed of a metal wire. Is a shielded cable formed by horizontally winding in opposite directions.

  The tape-shaped member may be a laminate tape of a metal foil and a resin, and the metal foil may be disposed toward the outer peripheral surface side to conduct with the second shielding layer.

  The tape-shaped member may be wrapped so that ends thereof overlap, and the winding direction of the tape-shaped member and the winding direction of the metal wire of the second shielding layer may be opposite.

  Also, a plurality of the electric wires are accommodated, and a presser winding is provided on an outer periphery of the plurality of electric wires, and the presser winding is formed by winding a resin tape, and the winding direction of the tape-shaped member and the resin The winding direction of the tape may be reverse.

  According to the present invention, the shielding layers are formed in three layers, and the shielding layers are electrically connected to each other. Therefore, even if a gap is generated in some shielding layers, it is possible to suppress a decrease in shielding characteristics. Further, since the shielding layer is composed of the tape-shaped member and the metal wire, the gap between the lines generated when the shield cable composed only of the metal wire is bent is closed by the tape-shaped member. For this reason, the fall of a shield characteristic can be suppressed.

  In addition, since the shielding layer made of tape-like member is arranged in the innermost layer and the shielding layer by the metal wire is formed on the outer peripheral side, the tape-like member that affects the flexibility of the shielded cable should be arranged as centrally as possible Can do. For this reason, the influence on the bendability of the shielded cable can be minimized. Moreover, since it presses with the metal wire from the outer periphery of a tape-shaped member, buckling etc. of a tape-shaped member can be pressed down with a metal wire, and a shield fall can be suppressed.

  Moreover, if the tape-shaped member is a laminate tape of a metal foil and a resin, the metal layer can be prevented from being broken or buckled. At this time, by arranging the metal layer toward the outer peripheral side, the outer peripheral metal wire and the metal foil can be made conductive. For this reason, a shield characteristic can be improved.

  Moreover, since a metal layer is wound without gap by wrap-wrapping a tape-shaped member and forming a shielding layer, a shield characteristic can be improved. At this time, by setting the winding direction of the tape-shaped member and the winding direction of the metal wire on the outer periphery thereof to be opposite directions, the tape-shaped member is reliably pressed by the metal wire, and when the shield cable is twisted, It can suppress that a clearance gap is formed in at least one.

  Moreover, since a plurality of electric wires are accommodated in the inside, it is possible to efficiently exhibit a shielding characteristic for each electric wire.

  ADVANTAGE OF THE INVENTION According to this invention, even if a shielded cable is bent, the shielded cable which can maintain a shield characteristic can be provided.

1 is a schematic perspective view showing a shielded cable 1. FIG. (A) is sectional drawing which shows the shielded cable 1, (b) is the elements on larger scale of shielding layer 7a, 7b, 7c. The figure which shows the repeated bending test method of the shielded cable sample 20. FIG.

  Hereinafter, a shielded cable 1 according to an embodiment of the present invention will be described. FIG. 1 is a schematic perspective view of the shielded cable 1, and FIG. 2A is a cross-sectional view of the shielded cable 1. The shielded cable 1 mainly includes an electric wire 3, shielding layers 7a, 7b, 7c, a jacket 9 and the like.

  A plurality of electric wires 3 are accommodated inside the shielded cable 1. The electric wire 3 includes a conductor 11 and an insulator 13 provided on the outer periphery of the conductor 11. For example, when the shielded cable 1 is used for a communication cable of an automobile, four electric wires 3 are twisted and accommodated, and the insulators 13 of the electric wires 3 are made of different colors of crosslinked polyethylene. In addition, the number of the electric wires 3 should just be one or more, and is not restricted to the illustrated example. Moreover, when the number of the electric wires 3 is a multiple of 2, it is preferable that the whole is twisted or a pair of twisted wires or quad-twisted wires (the above-mentioned four-twisted wires) are assembled. Furthermore, from the viewpoint of improving the high frequency characteristics, it is preferable that the number of the electric wires 3 is small, and specifically, it is preferable that the number is 1 to 4.

  A presser winding 5 is provided on the outer periphery of the plurality of electric wires 3. The presser winding 5 is formed by winding a resin tape. The presser winding 5 is not always necessary.

  A tape-shaped member 8 a is wound around the outer periphery of the presser winding 5. The tape-shaped member 8a has conductivity. The tape-like member 8a is wrapped so that the end portions overlap. That is, the tape-like member 8a is wound around the outer periphery of the presser winding 5 without a gap. When the presser winding 5 is omitted, the tape-like member 8 a is wound around the outer circumferences of the plurality of electric wires 3.

  The tape-shaped member 8a constitutes a shielding layer 7a that is a first shielding layer. In the present invention, it is expressed that the shielding layer 7 a as the first shielding layer is provided on the outer periphery of the electric wire 3 regardless of the presence or absence of the presser winding 5. Moreover, it is desirable that the winding direction of the tape-like member 8a and the winding direction of the resin tape of the presser winding 5 are opposite to each other.

  FIG. 2B is a partially enlarged view of the shielding layer 7a. The tape-shaped member 8 a is a laminate tape of the resin layer 15 and the metal foil 17. For example, the tape-shaped member 8 a is formed by laminating a metal foil 17 made of aluminum (including an aluminum alloy; the same applies hereinafter) or copper (including a copper alloy; the same applies hereinafter) on the surface of the polyester resin layer 15. It is formed.

  The tape-like member 8a may be a metal tape or a conductive resin tape instead of a laminate tape. For example, a tape made of aluminum or copper may be used. In any case, the shielding layer 7a formed on the outer periphery of the electric wire 3 is formed by winding a tape member 8a having conductivity.

  A shielding layer 7b as a second shielding layer is provided on the outer periphery of the shielding layer 7a. The shielding layer 7b is formed by horizontally winding a plurality of metal wires 8b. The metal wire 8b is, for example, a tinned annealed copper wire.

  Here, as for the tape-shaped member 8a, the metal foil 17 which comprises the shielding layer 7a is arrange | positioned toward the outer peripheral surface side. For this reason, the shielding layer 7a and the shielding layer 7b are directly conducted. It is desirable that the winding direction of the tape-like member 8a and the winding direction of the metal wire 8b of the shielding layer 7b are opposite to each other.

  A shielding layer 7c, which is a third shielding layer, is provided on the outer periphery of the shielding layer 7b. The shielding layer 7c is formed by horizontally winding a plurality of metal wires 8c. The metal wire 8c is, for example, a tinned annealed copper wire. The shielding layer 7b and the shielding layer 7c are directly connected. Moreover, it is desirable that the metal wires 8b and 8c constituting the shielding layer 7b and the shielding layer 7c are formed by laterally winding in opposite directions.

  A jacket 9 is provided on the outer periphery of the shielding layer 7c. The jacket 9 is made of resin.

  According to the present embodiment, the shielding layers 7a, 7b, and 7c are provided in a stacked manner, and are directly connected to each other. Therefore, the shielded cable 1 is deformed, for example, the metal wire 8b or the metal wire of the shielding layer 7b or the shielding layer 7c. Even when the line between the lines 8c is opened, it is possible to suppress the deterioration of the shield characteristics.

  Particularly, by forming the shielding layer 7a as the innermost layer among the shielding layers, the tape-like member 8a is wound at a position close to the center of the cross section, and the influence on the bendability of the shielded cable 1 is minimized. it can.

  Further, since the tape-like member 8a is pressed by the metal wires 8b and 8c from the outer peripheral side, the buckling and damage of the tape-like member 8a can be suppressed when the shield cable 1 is deformed. At this time, since the metal wire 8b is wound from the outer periphery after the tape-like member 8a is wound, fine irregularities due to the metal wire 8b are formed on the metal foil 17, and the flexibility of the tape-like member 8a is improved.

  Further, since the tape-like member 8a and the metal wires 8b and 8c are wound in order so as to be opposite to each other, the winding does not loosen when the shield cable 1 is deformed, and the same position of each layer It is also possible to suppress the occurrence of a gap in the surface.

  As described above, in the present invention, the shielded cable is repeatedly formed by combining the tape-like member 8a and the metal wires 8b and 8c and arranging the shielding layers 7a, 7b, and 7c in direct connection with each other in an appropriate stacking order. Even when bent, the shield characteristics can be maintained, and both high shield characteristics and repeated bendability can be achieved. For this reason, it is especially suitable for the wire harness of a motor vehicle.

  Next, the shield characteristics and cable appearance after repeated bending tests were evaluated for various shielded cables.

As for the shield characteristics, the results after repeated bending tests compared with the initial state are compared. When the change in characteristics is not substantially observed at a frequency of 100 to 5000 MHz, the change in characteristics (deterioration) is observed. Was marked with x.

  Regarding the appearance of the cable, the case where there was no substantial change on the sheath surface after repeated bending tests was marked with ◯, and the case where the sheath was uneven or damaged was marked with x.

  The repeated bending test is a method based on IEC 60227-2. As shown in FIG. 3, for each shielded cable sample 20, the outer diameter φ of the mandrel 21 is 100 mm and the load W by the weight 22 is 200 g. The film was bent 10,000 times at a bending angle of ± 90 ° at a speed of 30 times / minute.

  As each shielded cable sample, one containing four electric wires inside was used. Each electric wire was obtained by applying an outer sheath of a cross-linked polyethylene having a thickness of 0.305 mm to the outer periphery of a stranded wire (outer diameter 0.48 mm) of a tin-plated annealed copper wire, and the outer diameter was 1.09 mm. The four wires were a right-handed quad twist.

  On the outer periphery of the quad-twisted electric wire, a part of the shielded cable sample was removed, and a polyester tape was wound to the left to provide a presser roll (thickness 0.2 mm). Various shielding layers were formed on the outer periphery of the presser winding (or the outer periphery of the quad-twisted electric wire when there is no presser winding), and an outer cover having a thickness of 0.4 mm was applied to the outermost periphery. In either case, the outer diameter of the cable was about 4 mm.

  Sample No. No. 1 is provided with a shielding layer made of metal tape (a metal part is made of aluminum with a thickness of 0.02 mm and an overall thickness of 0.05 mm) on the outer periphery of the presser winding, and a metal wire (tin-plated annealed copper) is provided on the outer periphery. Wire: 0.1 mm in diameter) in opposite directions (in this case, the inner wire is left-handed and the outer wire is right-handed) and is wound horizontally to form two shielding layers to provide a total of three shielding layers The adjacent shielding layers were directly conducted.

  Sample No. 2 is Sample No. No. 1, press winding is omitted, and the laminated tape (a structure in which an aluminum foil is attached to a polyester sheet, the metal part is aluminum with a thickness of 0.02 mm, the entire thickness is applied to the outer periphery of the cable twisted by the quad. A shielding layer made of 0.1 mm) was provided.

  Sample No. 3 is sample no. 1 in place of the metal tape instead of the metal tape for the inner shielding layer. The same laminate tape as 2 was used.

  Sample No. 4 is Sample No. 1 except that the metal tape was removed and the metal wires (similar to sample No. 1) were horizontally wound in opposite directions to form two shielding layers.

  Sample No. Sample No. 5 1, a metal tape (similar to sample No. 1) was wrapped around the metal wire except for the metal wire shielding layer to form a single shielding layer.

  Sample No. Sample No. 6 1, a buffer layer (thickness: 0.1 mm) made of an insulator was provided between the shielding layers of metal wires. As the buffer layer, the above-mentioned sample no. A polyester tape similar to that of No. 1 was used.

  Sample No. In No. 7, a shielding layer was formed with a braided wire (knitted tin-plated annealed copper wire having a diameter of 0.1 mm) adjacent to the outer periphery of the presser winding.

  The results are shown in Table 1.

  No. Nos. 1 to 3 had good shielding properties and repeated bendability.

  On the other hand, no. In No. 4, the shielding characteristic was x. This is thought to be because a gap was generated between the metal wires due to repeated bending of the shielded cable.

  No. In No. 5, the appearance after repeated bending was x, and the shielding property was x. This is presumably because a part of the metal tape was damaged due to repeated bending of the shielded cable to deteriorate the shield characteristics. In addition, No. No. 5 further deteriorated the appearance due to the influence of damage to the metal tape.

  No. No. 6 has a shielding characteristic of x. This is no. This is probably because a gap was generated between the metal wires due to repeated bending of the shielded cable as in the case of No. 4.

  No. For No. 7, the appearance after repeated bending was x, and the shielding property was x. This is presumably because the braided wire was damaged by repeated bending of the shielded cable to deteriorate the shield characteristics, and the appearance was damaged due to the influence of the braided wire.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It will be obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Shielded cable 3 ......... Electric wire 5 ......... Pressure winding 7a, 7b, 7c ......... Shielding layer 8a ......... Tape-like member 8b, 8c ......... Metal wire 9 ...... Outer sheath 11 ... …… Conductor 13 ………… Insulator 15 ………… Resin layer 17 …… Metal foil 20 …… Shielded cable sample 21 ………… Mandrel 22 …… Weight

Claims (4)

Electric wires housed inside,
A first shielding layer provided on the outer periphery of the electric wire;
A second shielding layer provided on an outer periphery of the first shielding layer and directly conducting to the first shielding layer;
A third shielding layer provided on an outer periphery of the second shielding layer and directly conducting to the second shielding layer;
A jacket provided on the outer periphery of the third shielding layer;
Comprising
The first shielding layer is formed by winding a tape-like member having conductivity,
The shielded cable, wherein the second shielding layer and the third shielding layer are formed by laterally winding metal wires in opposite directions. The tape-shaped member is a laminated tape of metal foil and resin,
2. The shielded cable according to claim 1, wherein the metal foil is disposed toward the outer peripheral surface side to become the first shielding layer and is directly connected to the second shielding layer. The tape-shaped member is wrapped so that the ends overlap,
The shielded cable according to claim 1 or 2, wherein the winding direction of the tape-shaped member and the winding direction of the metal wire of the second shielding layer are opposite to each other. A plurality of the electric wires are accommodated, and a presser winding is provided on the outer periphery of the plurality of electric wires,
The pressing winding is formed by winding a resin tape, the tape-shaped member is wound around the outer periphery of the pressing winding, and the winding direction of the tape-shaped member is opposite to the winding direction of the resin tape. The shielded cable according to any one of claims 1 to 3, wherein

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