JP5277661B2 - Cable with shielding layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable with a shielding layer in which grounding work is unnecessary, and a differential signal cross talk is small between neighboring cables. <P>SOLUTION: The shielding layer 6 is formed by multiply winding discontinuous conductor shielding tape 5 having a conductor part 4 formed on a face of an insulating tape 2 and a slit 3 to electrically insulate the conductor part 4 so that no part is left uncovered by the conductor part 4. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a cable with a shielding layer that requires no grounding work and has small differential signal crosstalk between adjacent cables.

  In the pair-type metallic cable, the standardization of Ethernet (registered trademark) having a transmission rate of 10 Gbps is performed by the 802.3 standardization organization. In this way, high-speed transmission using differential signals in the physical layer is expected in the future. In the field of transmission using differential signals, it is important to suppress differential signal crosstalk between adjacent cables that occurs between a plurality of cable lines.

  The differential signal crosstalk between adjacent cables is not subject to compensation by an active cancellation function by LSI (Large Scale Integration) like the differential signal crosstalk in the same cable, and thus must be suppressed in the cable itself.

  However, for that purpose, in a pair-type metallic cable without a shielding layer, it is necessary to increase the distance between adjacent pairs of twisted wires, and the cable diameter must be increased intentionally. For example, in an unshielded cable without a shielding layer, differential signal crosstalk between adjacent cables can be suppressed to some extent by making the twist of the pair finer and intentionally increasing the diameter of the unshielded cable. However, it is not preferable to increase the diameter.

  In addition, in 10GBASE-T that performs transmission at 10 Gbps with a metal cable, differential signal crosstalk between adjacent cables directly affects transmission quality more directly than differential signal crosstalk in the same cable. The so-called Augmented Category 6 cable designed exclusively for such a communication system is the difference between adjacent cables in a combination of cables of the same manufacturer, such as products of Company A and products of Company B. The dynamic signal crosstalk can be suppressed within a predetermined value. However, when a combination of cables of different manufacturers, such as products of Company A and Company B, that is, cables with different designs are adjacent, differential signal crosstalk between adjacent cables cannot be suppressed. This is because different manufacturers have different combinations of conditions such as twisting pitch, assembly pitch, and sheath thickness, and these conditions behave as parameters for differential signal crosstalk between adjacent cables.

  Therefore, it is preferable to provide a shield layer for reducing unnecessary differential signal crosstalk between adjacent cables in the pair-type metallic cable.

  6 and 7 show a conventional pair-type metallic cable with a shielding layer (hereinafter simply referred to as a cable with a shielding layer). The cable 61 with a shielding layer has an inner skin 68 on the outer periphery of one or more pairs of twisted wires 67, has a shielding layer 66 on the outer periphery of the inner skin 68, and has an outer skin on the outer periphery of the shielding layer 66. 69. The shielding layer 66 is composed of a continuous conductor 64 without a break. The twisted pair wire 67 is formed by twisting two insulating core wires 71 in pairs. The shielding layer 66 is made of a tape or metal foil made of a conductor 64 continuous in the longitudinal direction. Further, an alpet tape in which an aluminum foil is pressure-bonded on the surface of an insulating tape such as polyethylene is used for the shielding layer 66. For example, a differential signal is transmitted to the core conductors 72 of the two insulated cores 71.

  The conventional cable 61 with a shielding layer has a sufficiently small differential signal crosstalk between adjacent cables as compared with a paired metallic cable without a shielding layer.

  In the conventional cable 61 with a shielding layer, since the shielding layer 66 is composed of a continuous conductor 64, the shielding layer 66 is short-circuited between both ends of the cable 61 with the shielding layer cut to an arbitrary length. . This is because the conventional cable 61 with a shielding layer is configured not only to suppress differential signal crosstalk but also to suppress noise of in-phase signals.

JP 2006-32193 A

  By the way, the conventional cable with a shielding layer needs to reliably ground the shielding layer at one end or both ends of the cable with the shielding layer depending on the electromagnetic environment in which the cable with the shielding layer is laid. However, it is difficult to reliably perform grounding. The reason is that the grounding confirmation method has been established only by visual inspection or continuity inspection by a tester, and the quality of grounding cannot be sufficiently confirmed. Moreover, grounding in high frequency signal transmission of MHz or higher is not the same as grounding in direct current or commercial power frequency of 50-60 Hz, and high frequency grounding equipment is necessary. Since there is no ground bonding equipment that can be grounded, it cannot be grounded reliably.

  Moreover, since the conventional cable with a shielding layer requires grounding work of the shielding layer at least at one end when construction (laying) is performed, the construction cost becomes high. That is, the construction cost becomes large if there is a grounding work because the construction cost occupies a large specific gravity more than double the material cost.

  However, if the shielding layer is released from the ground potential without grounding, the shielding layer may behave as an unexpected antenna for high frequencies. In addition, when a potential difference occurs between both ends of the cable with the shielding layer due to the influence of the electromagnetic field existing in the environment where the cable with the shielding layer is laid, current reflux for eliminating the potential difference may occur in the shielding layer.

  To summarize the above problems, a shielding layer is required to suppress differential signal crosstalk between adjacent cables, but there is a shielding layer because grounding work of the shielding layer is a cause of high construction costs. There is a potential demand for cables that do not require grounding.

  Accordingly, an object of the present invention is to provide a cable with a shielding layer that solves the above-described problems, does not require grounding work, and has a small differential signal crosstalk between adjacent cables.

To achieve the above object, according to the present invention, in a cable with a shielding layer comprising a shielding layer made of a conductor, a conductor portion formed on the surface of an insulating tape extending in the longitudinal direction, and the conductor portion in the longitudinal direction discontinuous conductor shielding tape having electrically slit insulation can be wound overlapping such that there is no uncovered portion by the conductor portion in which the shielding layer is formed.

The present invention also relates to a cable with a shielding layer having a shielding layer made of a conductor, a conductor part formed on both front and back surfaces of an insulating tape extending in the longitudinal direction, and electrically connecting the conductor part in the longitudinal direction. insulated, a slit formed so as not to overlap in each other physician front and back, are formed along the longitudinal edges of the front or back, discontinuous conductor shielding tape and an insulating portion covering the conductor portion The shield layer is formed by wrapping the conductor portions on the front surface and the back surface so as to overlap with each other via the insulating portion .

  The discontinuous conductor shielding tape may be wound vertically.

  You may have the said shielding layer in the outer periphery of a twisted pair wire.

  An inner skin may be provided on the outer periphery of the twisted wire, and the shielding layer may be provided on the outer periphery of the inner skin.

  The present invention exhibits the following excellent effects.

  (1) No grounding work is required.

  (2) The differential signal crosstalk between adjacent cables is small.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a cable 1 with a shielding layer according to the present invention includes a conductor portion 4 formed on the surface of an insulating tape 2 and a slit 3 that electrically insulates the conductor portion 4. The continuous conductor shielding tape 5 is overwrapped so that there is no portion that is not covered with the conductor portion 4, and the shielding layer 6 is formed.

  Inside the shielding layer 6, a conductor wire to be shielded is arranged. In the present embodiment, the conductor wire to be shielded is the twisted pair wire 7. The shielded cable 1 has an inner skin 8 on the outer periphery of one or more pairs of twisted wires 7, a shield layer 6 on the outer periphery of the inner skin 8, and an outer skin on the outer periphery of the shield layer 6. 9

  Since the twisted pair wire 7 is known conventionally, description is abbreviate | omitted. An inner skin 8 is formed around the twisted wire 7 with a thermoplastic such as polyvinyl chloride or polyethylene. The outer skin 9 serves as a protective layer for the shielding layer 6. The material of the outer skin 9 is a flexible plastic, but is not particularly limited. The thickness of the outer skin 9 is not particularly limited.

  As shown in FIG. 2, the discontinuous conductor shielding tape 5 has a conductor portion (a portion with a conductor) that covers the insulating tape 2 tightly on one side of the insulating tape 2 having a predetermined width and extending in the longitudinal direction. ) 4 and linear slits (portions where there is no conductor) 3 inclined obliquely with respect to the edge of the insulating tape 2 and extending to the opposite edge are periodically provided in the longitudinal direction of the discontinuous conductor shielding tape 5. . The discontinuous conductor shielding tape 5 includes a conductor portion 4 made of a metal foil such as aluminum or copper on the surface of the insulating tape 2 made of polyester, polyimide, or the like as a base material. It is formed by a process such as adhesion, pressure bonding, etching, and printing while providing slits 3 to divide and cut off conduction. The thickness of the insulating tape 2 is not particularly limited. The shape of the slit 3 and the shape of the conductor portion 4 are not limited to the illustrated parallelogram. It is sufficient that each conductor portion 4 is divided by the slit 3. The thickness of the conductor part 4 is not specifically limited.

  The discontinuous conductor shielding tape 5 is wound around the outer periphery of the inner skin 8. The discontinuous conductor shielding tape 5 is wound in layers.

  Here, in order to prevent the inner skin 8 from having a portion not covered with the conductor portion 4 of the shielding layer 6, the discontinuous conductor shielding tape 5 of FIG. . As a result, the exposed portion of the inner skin 8 (portion through which the inner skin 8 is exposed toward the outside in the radial direction) does not exist in one place on the entire circumference and the entire length of the cable 1 with the shielding layer.

  If the discontinuous conductor shielding tape 5 is wound around the outer periphery of the inner skin 8 in an arbitrary spiral shape without intending this, the portion that is not covered by the conductor portion 4 is circumferential or It exists in a predetermined cycle in the longitudinal direction. When the inner skin 8 is exposed, an impedance variation or an abnormal point of both reflection attenuation characteristics occurs in the twisted pair wire 7 due to the structural unevenness due to the portion.

  Therefore, in the present invention, the inner skin 8 is made such that there is no portion not covered with the conductor portion 4 of the shielding layer 6. Specifically, when the discontinuous conductor shielding tape 5 is wound on the outer circumference of the inner skin 8 in a single layer, the discontinuous conductors in the second and subsequent layers are arranged so that the conductor portion 4 overlaps the slit 3 of the discontinuous conductor shielding tape 5. The shielding tape 5 is spirally overlapped and wound. The width of the slit 3 is preferably sufficiently smaller than the width of the conductor portion 4 so that the cable 1 with a shielding layer can be easily wound and manufactured so that the slit 3 portion does not overlap. Preferably, the width of the slit 3 is set to about one tenth of the width of the conductor portion 4.

  Since the shielding layer 6 is formed by the discontinuous conductor shielding tape 5 having the discontinuous conductor portion 4 on one surface of the insulating tape 2 in the cable 1 with the shielding layer of FIG. The shielding layer 6 is not short-circuited between both ends of the cable 1 with the shielding layer cut out to a longer pitch than 3). Therefore, even if the shielding layer 6 is released from the ground potential without grounding the shielding layer 6 during construction, the shielding layer 6 does not behave as an unexpected antenna for high frequencies. Further, even if an electromagnetic field is present in the environment where the cable 1 with the shielding layer is laid, a potential difference does not occur between both ends of the cable 1 with the shielding layer, and current reflux for eliminating the potential difference occurs in the shielding layer 6. There is nothing. Therefore, the grounding work of the shielding layer 6 is not necessary.

  Moreover, since the cable 1 with a shielding layer of FIG. 1 does not have a part which is not covered with the conductor part 4 of the shielding layer 6 in the inner skin 8, the differential signal crosstalk between adjacent cables can be suppressed.

  A cable 1 with a shielding layer in FIG. 1 is a cable with a shielding layer that has a shielding effect of suppressing differential signal crosstalk between adjacent cables and does not require grounding work. Moreover, this cable with a shielding layer is a cable with a shielding layer in which structural inhomogeneity does not exist.

  Next, another embodiment of the present invention will be described.

  As shown in FIG. 3, the cable 31 with the shielding layer according to the present invention is provided with a discontinuous conductor shielding tape 35 having discontinuous conductor portions 34 divided by slits 33 on the surface of the insulating tape 32. The shielding layer 36 is formed by being wound.

  Inside the shielding layer 36, a conductor wire to be shielded is disposed. In the present embodiment, the conductor wire to be shielded is a twisted pair wire 37. The cable 31 with a shielding layer has an inner skin 38 on the outer periphery of one or more pairs of twisted wires 37, a shielding layer 36 on the outer periphery of the inner skin 38, and an outer skin on the outer periphery of the shielding layer 36. 39.

  In this embodiment, in addition to the discontinuous conductor shielding tape 35 being vertically attached, the discontinuous conductor shielding tape 35 has discontinuous conductor portions 34 divided by slits 33 on both front and back surfaces, It is characterized in that the slits 33 on the front and back sides do not overlap each other and that the discontinuous conductor shielding tape 35 has an insulating part 41 that covers the conductor part 34.

  As shown in FIG. 4, the discontinuous conductor shielding tape 35 has a conductor portion (a portion with a conductor) that covers the insulating tape 32 on both sides of the insulating tape 32 having a predetermined width and extending in the longitudinal direction. ) 34 and linear slits (portions where there is no conductor) 33 inclined obliquely with respect to the edge of the insulating tape 32 are periodically provided in the longitudinal direction of the discontinuous conductor shielding tape 35. The discontinuous conductor shielding tape 35 includes a conductor portion 34 made of a metal foil such as aluminum or copper on the front side surface and the back side surface of an insulating tape 32 based on polyester, polyimide, or the like. 34 is formed by a process such as adhesion, pressure bonding, etching, and printing while providing a slit 33 in order to divide 34 in the longitudinal direction of the tape and cut off conduction. By preventing the position where the slit 33 on the front side surface is formed from the position where the slit 33 on the back side surface is slightly overlapped, it is possible to prevent deterioration of the characteristics of the twisted wire due to the above-described structural unevenness. That is, as shown in FIG. 5A and FIG. 5B, the position where the slit 33 is on the front side always has the conductor 34 on the back side and the position where the slit 33 is on the back side. There is always a conductor 34 on the front side.

  Further, as shown in FIG. 4, an insulating portion 41 that covers the vicinity of the edge of the conductor portion 34 along the edge is provided on one side of the discontinuous conductor shielding tape 35 over the entire length in the longitudinal direction. The insulating part 41 is formed by painting or attaching a separate insulating tape. The width of the insulating portion 41 is set to be equal to or larger than the difference between the width of the discontinuous conductor shielding tape 35 and the outer peripheral length of the inner skin 38. If the width of the insulating portion 41 is shorter than this, the conductor portions 34 on the front and back surfaces come into contact.

  The discontinuous conductor shielding tape 35 is wound vertically around the outer periphery of the inner skin 38.

  Since the discontinuous conductor shielding tape 35 has the conductor portions 34 on the front and back, when the longitudinally wound on the outer periphery of the inner outer skin 38, the conductor portions 34 on the front and back contact each other, and the shielding layer cut out to an arbitrary length The shielding layer 36 may be short-circuited between both ends of the attached cable. Therefore, in the present invention, the insulating portion 41 that covers the conductor portion 34 is provided on one surface of the discontinuous conductor shielding tape 35. When the discontinuous conductor shielding tape 35 is wound vertically, the conductor portions 34 do not directly contact each other and overlap each other via the insulating portion 41, so that electrical isolation can be maintained.

  The cable 31 with a shielding layer in FIG. 3 is a cable with a shielding layer that has a shielding effect of suppressing differential signal crosstalk between adjacent cables and does not require a grounding operation. Moreover, this cable with a shielding layer is a cable with a shielding layer in which structural inhomogeneity does not exist.

  In the said embodiment, the cables 1 and 31 with a shielding layer have inner skins 8 and 38 on the outer periphery of a plurality of pairs of twisted wires 7 and 37, and the discontinuous conductor shielding tape 5 on the outer periphery of the inner skins 8 and 38. , 35 and the outer skins 9, 39 on the outer periphery of the shielding layers 6, 36, but the present invention is not limited to this structure. For example, the inner skins 8 and 38 can be omitted, and the insulating tapes 2 and 32 of the discontinuous conductor shielding tapes 5 and 35 can be made to have an appropriate thickness to replace the inner skins 8 and 38.

  As described above, according to the present invention, differential signal crosstalk between adjacent cables can be suppressed, and grounding work becomes unnecessary, so the construction cost is the construction cost of a cable without a shielding layer. Reduced to the same extent.

  The cable with a shielding layer according to the present invention can be used in a high-speed differential signal transmission system.

  The cable with a shielding layer according to the present invention is used for a wiring system having a topology as represented by JISX5150 and also used as a cable for a cord with modular plugs at both ends.

It is the structure figure which looked at the terminal of the cable with a shielding layer which shows one Embodiment of this invention from the side surface. It is a perspective view of the discontinuous conductor shielding tape used for the cable with a shielding layer of FIG. It is the structure figure which looked at the terminal of the cable with a shielding layer which shows other embodiment of this invention from the side surface. It is a perspective view of the discontinuous conductor shielding tape used for the cable with a shielding layer of FIG. (A) and (b) are the figures of the front side surface and back side surface (perspective view) of the discontinuous conductor shielding tape of FIG. It is the structure figure which looked at the terminal of the cable with the conventional shielding layer from the side. It is sectional drawing of the conventional cable with a shielding layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,31 Cable with shielding layer 2,32 Insulating tape 3,33 Slit 4,34 Conductor part 5,35 Discontinuous conductor shielding tape 6,36 Shielding layer 7,37 Twisted wire 8,38 Inner skin 9,39 Outside Hull

Claims (5)

In a shielded cable with a shield layer made of a conductor,
A portion in which a discontinuous conductor shielding tape having a conductor portion formed on the surface of the insulating tape extending in the longitudinal direction and a slit for electrically insulating the conductor portion in the longitudinal direction is not covered with the conductor portion. A cable with a shielding layer, wherein the shielding layer is formed by being overwrapped so as not to have a gap. In a shielded cable with a shield layer made of a conductor,
A conductor portion formed longitudinally elongated insulating tape of both sides on the electrically insulates the conductor portion in a longitudinal direction, a slit formed so as not to overlap in each other physician front and back, A discontinuous conductor shielding tape formed along the longitudinal edge of the front surface or the back surface and having an insulating portion covering the conductor portion is overlapped so that the conductor portions on the front surface and the back surface overlap with each other via the insulating portion. has been shielding layer with cable, characterized in that the shielding layer is formed. The cable with a shielding layer according to claim 2 , wherein the discontinuous conductor shielding tape is vertically attached. Shielding layer with cable according to any one of claims 1 to 3, characterized in that having the shielding layer on the outer periphery of the twisted pair. The cable with a shielding layer according to any one of claims 1 to 3 , further comprising an inner skin on an outer periphery of the twisted pair wire, and the shielding layer on an outer periphery of the inner sheath.

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