JP2007220495A - Ultrafine cable assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrafine cable assembly which has a high durability in a usage including bending and twisting. <P>SOLUTION: The ultrafine cable assembly in which a plurality of ultrafine cables 10... are clubbed together and banded by a protective tape 30 is provided with a twisting part 320 on the cable assembly part at least on one end of a tape-covered part 310 by the protective tape 30, when the ultrafine cable assembly is used repeatedly by twisting in a direction around a cable band circumference. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrafine cable assembly having high durability under use conditions such as bending and twisting.

In recent years, in small electronic devices for consumer use, such as mobile phones, digital cameras, video cameras, portable music recorders, small portable personal computers, etc., a micro coaxial cable assembly (aggregation) in which a plurality of micro coaxial cables are assembled as a wiring material. Body) has been used frequently.
This is presumably because the assembly flexibility is high due to the stable transmission characteristics of the ultra-fine coaxial cable and the thin and flexible flexibility, which matches the needs of small electronic devices.

  An example of a conventional micro coaxial cable assembly is shown in FIG. In this micro coaxial cable assembly CA0, a plurality of micro coaxial cables 10 are assembled to provide connection portions 20 and 20 such as a substrate and a connector at both ends thereof, and a plurality of micro coaxial cables between the connection portions 20 and 20 are provided. For the coaxial cables 10..., Except for the cable connection portion of both the connecting portions 20, 20, the protective tape 30 is usually applied and bundled so that the fine coaxial cables 10. It is.

The micro coaxial cable assembly having such a structure has been conventionally used in, for example, an open / close type mobile phone (two-fold type in which a cover body (lid body) is opened and closed with respect to a telephone body) (Patent Document) 1) It is used for a rotary type mobile phone (where a cover body (cover body) rotates as 180 °, 360 °, etc. with respect to a telephone body). In these cases, in the micro coaxial cable assembly wired in the hinge part (rotating part) between the telephone body and the cover body, the bending or A complex force such as twisting acts.
JP-A-06-152491

  The miniature coaxial cable assembly is wired in a narrow space because the mobile phone itself is becoming smaller and the wiring space cannot be widened. On the other hand, depending on the structure of the phone, the hinge part between the phone body and the cover body Since it is wired in a complicated form that passes, it often becomes an impossible wiring form.

  For example, as shown in FIG. 5, one connecting portion 20 of the micro coaxial cable assembly is connected to a tape covering portion (cable bundle portion, that is, cable assembly shaft) to which a protective tape 30 is applied due to structural requirements of a mobile phone. In some cases, wiring is performed (in a bent state) with a certain angle θ with respect to the portion. In this case, since each cable of the cable assembly shaft portion is only bundled almost in parallel, a tensile distortion occurs in a cable near the outside of the bend, and a cable near the inside of the bend does not. A compression distortion occurs.

  When the opening / closing operation of the mobile phone is repeated under such a wiring state, a complicated force such as bending and twisting acts on the cable assembly shaft portion. As a result, the above-mentioned bent wiring is inherently distorted, and these complicated forces are applied to the cables on the outside and the cables on the inside. Eventually, some cables are cracked or disconnected, etc. Communication failure sometimes occurred.

  Therefore, the present inventors have intensively studied in order to improve these communication failures, and when the connection portion of the micro coaxial cable assembly is wired in a bent state, the tape covering portion to which the protective tape is applied. It has been found that when a twisted portion is provided in the cable assembly portion of at least one terminal, the number of operations until the cable is disconnected, that is, the number of times of cable disconnection, is remarkably improved.

  The number of times of cable disconnection is determined by preparing a bending test device that simulates the bending mechanism corresponding to the telephone body and cover body of the mobile phone, and providing a twisted portion at the cable assembly portion of at least one end of the tape covering portion. The connection portion of the coaxial cable assembly was bent and wired at a certain angle, and was subjected to a bending test in which bending by twisting such as rotation was repeated.

  According to this bending test, when the twisted part is not provided at the end of the cable assembly part, the cable is disconnected even if it is usually 20,000 times or less, whereas when the twisted part is provided at the end of the cable assembly part. Although it depends on conditions such as the type of cable used and the outer diameter, it has been found that there is no cable disconnection even after bending 100,000 times or more.

  The present invention has been made on the basis of such a fact. In an ultrafine cable assembly in which a large number of ultrafine cables such as an ultrafine coaxial cable that is bent and wired and used under a twisted state such as a bend is bundled, a tape is used. By providing a twisted portion in the cable assembly portion of at least one of the covering portions (both are possible), it is possible to provide a very thin cable assembly that is hard to break and has high durability.

  According to the first aspect of the present invention, in the ultra-fine cable assembly in which a plurality of extra-fine cables are assembled and these extra-fine cables are bundled with a protective tape, the extra-fine cable assembly is twisted in the circumferential direction of the cable bundle. In repeated use, a twisted portion is provided in the cable assembly portion of at least one end of the tape covering portion to which the protective tape is applied.

  According to the ultrafine cable assembly according to the present invention, the twisted portion is provided in the cable assembly portion of at least one end of the tape covering portion, so that it is difficult to break and high durability is obtained.

FIG. 1 shows an example of an ultrafine cable assembly according to the present invention.
This extra-fine cable assembly CA1 is basically of the same structure as the extra-fine coaxial cable assembly CA0 of FIGS. 4 to 5 described above, and uses an extra-fine coaxial cable as the extra-fine cable 10, but is protected. The difference is that a twisted portion 320 is provided by twisting the cable assembly portion of one end of the tape covering portion 310 to which the tape 30 is applied. Reference numeral 20 denotes a connection portion such as a substrate or a connector.

  As is apparent from FIG. 2, the twisted portion 320 is provided in the boundary region between the terminal portion of the cable assembly portion of the tape covering portion 310 and the cable connection margin portion of the connecting portion 20. In this formation, although not particularly limited, it is only necessary to twist at least 0.5 turn or more in the circumferential direction at each end portion of each small diameter cable 10. Good. This twisting may be preferably performed before the covering of the protective tape 30, but can be performed after the covering of the protective tape 30. Furthermore, it can be performed at the time of wiring. Further, the width (length) of the twisted portion 320 differs depending on the use of the cable, the total length of the cable, the outer diameter of the cable, etc., but it is sufficient if the length is about the width of the connector. In addition, when twisting a plurality of times, it is also possible to twist like an SZ stranded wire that alternately changes the twisting direction. In this case, as described later, a greater stress relaxation function can be obtained.

  Although the outer diameter of the extra-fine cable 10 is not specifically limited, A thing about 0.2-0.4 mm can be mentioned. The extra-fine coaxial cable as the extra-fine cable 10 is not particularly limited, but for example, the one shown in FIG. 3 can be used. In the case of this ultra-fine coaxial cable, the center conductor 11 is made of a stranded wire conductor of an ultra-thin metal wire (copper wire or the like), and the outer periphery of the center conductor 11 is covered with an insulator 12 made of fluorine resin such as Teflon (registered trademark). It is. Further, an outer conductor 13 made of an extremely fine metal wire (copper wire or the like) is provided on the outer periphery of the insulator 12, and a sheath (outer jacket) made of a fluorine resin such as Teflon (registered trademark) is provided on the outermost layer. Is provided.

  The protective tape 30 of the tape covering portion 310 is not particularly limited, but it is preferable to use a plastic tape. In particular, it is desirable to use a plastic tape that is strong, excellent in protective function, and highly resistant to trauma. In addition, an adhesive layer (adhesive layer) may be provided on the surface on the ultrafine cable side in advance in consideration of improvement in workability.

  When the extra-fine cable assembly CA1 of the present invention having such a structure is used for, for example, an open / close type mobile phone (a cover body (cover) that opens and closes at 90 ° to 180 ° with respect to the telephone body). Due to structural requirements of the mobile phone, etc., as shown in FIGS. 1 and 2, one of the connection portions 20 (right side in the figure) is wired with a certain angle θ with respect to the tape covering portion 310. However, sufficient durability is ensured.

  By the way, 30 ultrafine cables 10 mm of 0.3 mm are bundled to make an ultrafine cable assembly provided with a twisted portion having the same structure as in FIG. 1, and this is formed into a bending mechanism corresponding to a telephone body and a cover body of a mobile phone. Was set in a state where one of the connecting portions was bent. At this time, the length of the tape covering portion of the ultrafine cable assembly is 70 mm, the length of the twisted portion is 15 mm, and the number of twists is one. In addition, the bending angle θ of the connecting portion is two types of 45 ° and 90 °. The rotation angle (twisting angle) of the bending mechanism in the bending test apparatus was ± 180 °.

  And the bending test apparatus added 0-180 degree | times bending to the said ultrafine cable assembly. For reference, an ultrafine cable assembly having the same structure as that shown in FIG. 4 without a twisted portion is also subjected to 0 to 180 ° under the same conditions as described above. Bending was added.

As a result, in the case of the ultra-thin cable assembly having the same structure as that in FIG. 1, no cable breakage occurred even if the rotation was performed 100,000 times at either a bending angle of 45 ° or 90 °.
On the other hand, in the case of the ultrafine cable assembly having the same structure as that in FIG. 4, cable breakage occurred at a rotation of 20,000 or less at any bending angle of 45 ° or 90 °.

  From this, it can be seen that the ultra-thin cable assembly of the present invention shown in FIG. 1 can obtain high durability under use conditions such as twisting. The reason for this durability improvement is presumed as follows. When there is no twisted portion, each cable extending from the end of the tape covering portion 310 that is bundled substantially in parallel is directly connected in parallel to the connection portion such as a connector. In the area of the twisted part, this part is distorted because the cable is bent near the inner side of the bend and the cable is bent. Since the outer cable and the inner cable are switched at the boundary, it is considered that the stress concentration on the specific cable is alleviated.

  In the ultrafine cable assembly of the present invention, an ultrafine coaxial cable is used as the ultrafine cable, but the present invention is not limited to this. A cable in which a large number of fine wires are twisted, or a conductor portion simply arranged in parallel or a single wire conductor portion of the fine wires is covered with an insulator may be used.

It is the schematic plan view which showed an example of the ultrafine cable assembly which concerns on this invention. It is the enlarged plan view which showed the twist part in the cable assembly part of one terminal in the extra fine cable assembly of FIG. FIG. 2 is an enlarged end view showing an example of an extra fine cable used in the extra fine cable assembly of FIG. 1. It is the schematic plan view which showed the conventional micro coaxial cable assembly. It is the schematic plan view which showed the state which bent and wired one connection part of the micro coaxial cable assembly of FIG.

Explanation of symbols

CA1 ... extra fine cable assembly, 10 ... extra fine cable, 20 ... connection part, 30 ... protective tape, 310 ... tape covering part, 320 ... twisted part

Claims (1)

In the ultra-fine cable assembly in which a plurality of extra-fine cables are assembled and these extra-fine cables are bundled with a protective tape, the protective tape is used when the extra-fine cable assembly is repeatedly twisted in the circumferential direction of the cable bundle. An ultra-fine cable assembly, wherein a twisted portion is provided in a cable assembly portion of at least one end of the tape covering portion to which the above is applied.

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