JPH04104407A - Cable for electronic device - Google Patents

Abstract

PURPOSE:To achieve an equivalent shield effect to that of a braided shield by forming a double structure shield layer of an aluminum/plastic laminate tape and a metal woven combined with each other. CONSTITUTION:A plurality of cable core wires 1 are assembled or twisted with each other, an aluminum/plastic laminate tape 2 and a metal woven tape 3 woven of metal are spirally wound or vertically applied with either of them on the inner side to form a double structure shield layer, and a protective sheath 5 is provided on the outer circumference. In this case, a drain wire for grounding is inserted to get in contact with either or both of the metal woven tape 3 and the aluminum/plastic laminate tape 2. Fiber yarn may be used in part of either or both of warps and wefts of the tape 3 in such a degree as to give no bad effects to a shielding for improving the flexibility further. The double shield layer of the tape 3 and the tape 2 achieves a sufficient electromagnet shielding action. The shield layer formed by spiral winding or vertical application increases the flexibility of an obtained cable by relative movement of its lap parts.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a shielding effect as a shield layer that is almost equivalent to that of a conventional smeared annealed copper wire braid (hereinafter referred to as "shield braid"). The present invention relates to a novel cable for electronic equipment that can exhibit significantly superior bending characteristics compared to conventional cables.

[Prior Art] Recent digital electronic devices are becoming increasingly densely packaged and becoming more accurate and sensitive, and countermeasures against electromagnetic noise have become an important issue.

As a countermeasure against electromagnetic noise on electric wires and cables wired to electronic devices such as those mentioned above, a shielding layer is generally installed around the outer periphery of the electric wires. In order to form this shield layer, conventionally, the outer periphery of the insulated core wire is braided with tin-plated annealed copper wire, wrapped with copper tape, covered with aluminum pipe, wrapped with laminate tape made of vapor-deposited aluminum or copper around polyester tape, or Vertical attachment, and furthermore, coating with a conductive composition made by mixing an organic polymer compound with a conductivity-imparting agent such as carphone or metal powder has been carried out.

In particular, recently, the fourth method has been developed to prevent moisture from entering through the metal laminate tape, as well as the above-mentioned Nhunhart effect.
As shown in the figure, aluminum/polyester tape 2 is made by laminating an aluminum/plastic laminate tape, for example, aluminum and polyester tape, on the outer periphery of twisted cable cores 11 (hereinafter, this aluminum/polyester tape will be explained as a representative example). ) and the shield braid 101
Alternatively, there are many examples in which a two-layer shield layer is formed by combining a horizontally wound shield made of horizontally wound metal wire, and a protective sheath 5 is provided around the outer periphery to improve its reliability and shielding characteristics. became.

[Problem to be solved by the invention] In forming the double shield layer as described above, when the folded braid 101 is used as one of the shield layers, the intersecting movement of the metal wires for forming the braid is complicated. Therefore, the working speed of the braiding machine is very slow, and in addition, in this braiding machine, the core on which the shield braid is applied has already undergone the previous processes, such as twisting the core wires and winding with tape, at a relatively high speed. Since all the steps to be performed must be completed, there are large differences in working speed between each step, and it is necessary to remove an intermediate bobbin for replacement when loading it on the braiding machine. For two reasons, there is an inconvenience that results in a great deal of inefficiency in process control.

Further, in the case of a double shield layer configuration in which the shield braid 101 is combined with the aluminum/polyester tape 2, there is a problem that the flexibility of the cable itself is reduced.

In addition, when each core wire is taken out individually at the terminal of a cable equipped with a shield braid, it is necessary to remove the shield braid 101 over the required length of the terminal portion, or this braid can be easily unraveled. Since it is impossible to do so, it is necessary to cut the shield braid into a cylindrical shape using a special scissor-like tool.
In this way, terminal processing is extremely troublesome and time-consuming.

Additionally, in a configuration that combines horizontally wound shields and aluminum/polyester tubes, there is a limit to the number of wraps that can be wrapped in horizontally wound work, making it impossible to apply to thick cables.
-1 There is a problem in that the shielding properties are inferior compared to the above shield braid.

[Means for Solving the Problems] The present invention has been made to solve the various problems described above, and consists of collecting or twisting a plurality of cable core wires, and applying an aluminum/plastic laminate tape and an aluminum/plastic laminate tape to the outer periphery thereof. A metal woven tape woven from metal wire is wrapped horizontally or vertically with one side facing inside.
A shield layer with a layered structure is formed, and a protective sheath is provided around the outer periphery of the shield layer. or a part of one or both of the warp and/or weft threads of the metal woven tape to the extent that the shielding effect is not adversely affected. Ml yarn is used.

[Operation] The dual layers of metal woven tape and aluminum/polyester tape provide sufficient electromagnetic shielding.

The shield layer formed by horizontal winding or vertical splicing improves the flexibility of the cable due to the relative movement of the overlapping windings.

The wrapped inner and outer shield layers can be easily unwound to facilitate terminal processing.

[Embodiment] The present invention will be described in detail with reference to FIGS. 1(A) and 1(B).

In FIG. 1, a plurality of cable core wires 1 each having an insulating coating 1b provided around a conductor 1a are simply gathered together or twisted together and bundled. Around this bundled cable core wire 1, an aluminum/polyester tube 2 is wound horizontally or vertically with an appropriate amount of overlap. On top of the lever, a metal woven tape 3, which will be described later, is wound horizontally or vertically with an appropriate overlap interval. The appropriate overlapping interval here means, for example, that the tape is wound one after the other by half or 1/3 of the tape width, and these are called 1/2 lap and 1/3 lap, respectively.

Furthermore, a suitable synthetic resin H is added to the metal woven tape 3.
A presser tape 4 made of a material is applied, and a protective cover 5 is provided around the outer periphery of the tape 4.

The horizontal wrapping or vertical splicing layer of the aluminum/polyester tape 2 has the role of a shield layer and a moisture-permeable IJ layer, and its installation position is shown in Figure 1 (
As shown in A), it may be provided inside the metal woven tape 3, or conversely, it may be provided outside thereof.

Furthermore, a grounding drain wire (not shown in FIG. 1) may be inserted to further stabilize grounding.

FIGS. 2 and 3 are explanatory diagrams showing two structural examples of the metal woven tape 3 installed as described above to form a shield layer.

In the structure example shown in FIG. 2, both the warp threads 3a and the weft threads 3b are plain woven using a metal system such as Susumenki annealed copper wire, and in FIG. This shows an example in which an appropriate synthetic fiber yarn 3c is woven into the fabric.

In this way, by using polyester fiber yarn within a range that does not affect the shielding properties, it is possible to increase flexibility, reduce yarn breakage, and improve manufacturing efficiency.

In addition, when flexibility is particularly important, an appropriate synthetic fiber yarn with excellent elasticity, such as polyester ffl Iff yarn, may be used as the weft yarn 3b, thereby providing almost the same flexibility as that of horizontally wound rolled yarn. It becomes possible to have sex.

Regarding the metal woven tape 3 used in this invention,
In other words, a so-called plain weave tape in which one weft and one warp thread are intertwined is sufficient, but other twill tapes and tapes with other weaving methods can be equally used.

Example 1 A 28 WG bulk soot coated conductor was coated with polyethylene to a thickness of 0.23 mm and an outer diameter of 0.84 mm.
The insulated core wires are extruded and coated to form an insulated core wire, and the insulated core wires are twisted in pairs in a left-handed manner so that the twist pitch of the insulated core wires is 10 to 30 mm, and the pitch of adjacent pairs of twists is different. We gathered 13 pairs. Aluminum thickness: 10 μm 1 Polyester tape thickness: 12 μm 1 Width: 3
A 5 mm aluminum/polyester tape was wrapped in a 1/3 to 1/2 wrap with the aluminum side facing outside.

Separately, 0.12 TA (tinned annealed copper wire with a wire diameter of 0.12 mm, hereinafter referred to as a wire) was used as a wire, and the number of warp threads was 190, the number of weft threads was 2, and the pitch P = 1.5 mm to form a plain weave. A plain woven metal tape with a width of 35 mm was manufactured.
1/3 to 1/2 on top of the above aluminum/polyester tape
Wrap it in layers with a wrap, and then roll it up to a thickness of 12 mm.
It was pressed and wrapped with a μm polyester tape. In this case, the thickness of PVC is 1.1 by tube type.
Extrusion coated so that the finished outer diameter is approximately 9.1 mm.
A cable of the present invention as shown in FIG. 1 was manufactured.

On the other hand, in order to obtain a conventional example as a comparative example for item 1, the assembly is the same as above, and on top of that, aluminum/polyester with the same aluminum thickness and polyester tape thickness and the same width of 35 mm as above. Wrap the tape in 1/3 to 1/2 wraps so that the aluminum side is on the outside.
On top of that, a rolled braid was applied using the same 0.12TA as in -1- as a wire so that the density was 90%. The braiding conditions in this case are 12 wires with a weight of 16 strokes and a pitch of P-38 mm.

Furthermore, on top of this, a PVC sheath is placed in a tube type with a thickness of 1.1 mm.
Extrusion coated to a diameter of 9.1 mm.
A conventional cable as shown in the figure was obtained.

FIG. 5 is a diagram showing the results of measuring the shielding effect of the present invention and the conventional example manufactured as described in section 1. As is clear from this figure, the present invention is almost equivalent to the conventional example. It can be seen that it can exert a shielding effect.

Next, a bending test was conducted on the present invention and the conventional example described in 1. by the test method shown in FIG.

A test cable 10 in which all core wires are connected in series and a voltage of several volts is applied from a constant voltage source is held between chucks 11 as shown in FIG.
The bending of 2-3-4 is counted as one time, and when the resistance value increases by 20% compared to the initial resistance value, it is determined that the wire is disconnected.
It counts the number of bends it takes to reach that point.

Five test samples were used in each case.

Table 1 shows the test results of the present invention, and Table 2 shows the test results of the conventional example.

As is clear from the comparison between Tables 1 and 2, it can be seen that the cable of the present invention exhibits extremely superior bending resistance compared to the conventional cable.

[Effects of the Invention] As described above, the present invention provides a shielding effect equivalent to that of a braided tape by forming a two-layered shielding layer that combines an aluminum/plastic laminate tape and a metal woven tape. The shield layer formed of woven tape is not fixed in a cylindrical shape like a braided shield layer, but is simply a flat tape wound into a cylindrical shape with an appropriate amount of overlap. Because of this, relative movement is possible between these stacked layers, and therefore, the cable is flexible enough to follow bending in any direction, and the bending characteristics can be greatly improved. In addition, metal woven tape does not require cutting work like shield braiding when processing the end, and just like aluminum/plastic laminate tape, it can be rolled and removed, making the end processing easier and improving the end work.

Furthermore, from the viewpoint of cable manufacturing, in the conventional braided wrap, the braided shield cannot be manufactured in advance and a braiding process is always required after the assembly and twisting. The metal woven tape is manufactured in advance in two separate culms, making it possible to form a two-layer shield layer on the same production line as the assembly and twisting of cable core wires, reducing costs by shortening the process. It is possible to downsize or shorten the delivery time.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, (A)
is a sectional view, (B) is a simplified side view, FIGS. 2 and 3 are plan views showing the metal woven tape used in the present invention, FIG. 4 is a sectional view showing an example of a conventional braided shielded cable, and FIG.
The figure is a diagram showing the measurement results of the shielding effect of the cable of the present invention and that of a conventional cable, and FIG. 6 is an explanatory diagram explaining the bending test method. 1 Cable core, 2 Aluminum/polyester tape, metal plain weave tape, polyester tape, protection system.

Claims (5)

[Claims] (1) Gather or twist multiple cable core wires, and wrap aluminum/plastic laminated tape and metal woven tape made of metal wire around the outer circumference horizontally or vertically so that one side is on the inside. A cable for electronic equipment characterized by forming a shield layer with a two-layer structure. (2) The cable for electronic equipment according to claim 1, wherein a drain wire for grounding is inserted so as to be in contact with the metal side of one or both of the metal woven tape and the aluminum/plastic laminate tape. (3) The cable for electronic equipment according to claim 1 or 2, wherein a fiber thread is used as a part of one or both of the warp and weft of the metal woven tape. (4) The cable for electronic equipment according to claim 3, wherein polyester fiber yarn is used only for the weft. (5) The cable for electronic equipment according to claim 3, wherein polyester fiber yarn is used at the outermost edge of the warp.