JP2013097924A - Signal cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal cable that can eliminate twisting, and avoids breaking of a wire and improves efficiency of laying/removing operation.SOLUTION: The signal cable includes two conductors 10 extending side by side along an axis P, a shield wire 12 covering the conductors 10 on the whole from outside, a shape memory alloy plate 11 covering the shield wire 12 further from outside, and a cover 13 covering all of them from outside. The shape memory alloy plate 11 holds the conductors 10 and the shield wire 12 inside to regulate relative rotation around the axis P, can regulate them from rotating relatively to the cover 13, and when the conductors and the shield wire are twisted to one peripheral side of the axis P, restoring force is made to operate toward the other peripheral side of the axis P with the conductors 10, the shield line 12, and the cover 13 in one body.

Description

  The present invention relates to a signal cable used when various measurements are performed particularly in a gas turbine or a steam turbine.

  When a new device such as a gas turbine or steam turbine is manufactured, when maintenance work is performed after a certain period of operation, or when a trouble occurs, the presence or absence of cracks is measured using a strain gauge, for example, to check the safety of the device. We are trying to improve reliability. Various measurements such as vibration measurement by an acceleration sensor during gas turbine operation and combustion pressure measurement by a pressure sensor in a gas turbine combustor are also performed.

  When performing such various measurements, various signal cables for measurement are used. This signal cable is often expensive due to its heat resistance, etc., and cannot be made disposable, and the cost is reduced by using or reusing rental products.

  As described above, since these signal cables are used a plurality of times, they are wound on a cable reel or the like when the measurement is completed. However, when the signal cable is laid, the signal cable is twisted, and if winding is performed with such a twist, the cable may be bent or disconnected. In addition, the signal cable becomes tangled during winding, and when such a signal cable is used again, it is necessary to pull out all the signal cables from the cable reel once, and this work takes time.

  Here, Patent Literature 1 discloses a signal transmission cable in which a wire made of a shape memory alloy is passed along with a conductor wire that transmits a signal. According to the technique of this patent document 1, even if a signal transmission cable is bundled or wound, for example, based on the memorized shape of the wire of the shape memory alloy, it is possible to return to the original linear shape. Yes.

Japanese Unexamined Patent Publication No. 7-6635

  However, in the signal cable (signal transmission cable) of Patent Document 1, it is inevitable that relative rotation occurs between the shape memory alloy and the conductive wire (conductor wire), and the twist of the signal cable can still be eliminated. could not.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a signal cable that can eliminate twisting and can avoid disconnection and improve the efficiency of laying removal work.

In order to solve the above problems, the present invention employs the following means.
That is, the signal cable according to the present invention holds the conducting wire inside such that the conducting wire extending along the axis and the relative rotation of the conducting wire around the axis can be restricted, and twisted to one side in the circumferential direction of the axis And a torsion preventing member that generates a restoring force on the other side in the circumferential direction.

  According to such a signal cable, the relative rotation between the twist preventing member and the conductive wire is restricted, and the restoring force works to restore the twist when the twist is generated by the twist preventing member. The twist preventing member and the conducting wire are integrated, and the twist is automatically eliminated.

  The twist preventing member may be a shape memory alloy extending along the axis.

  Such a shape memory alloy restricts relative rotation between the torsion prevention member and the conductive wire, and further restores the signal cable so that it returns to the shape previously stored in the shape memory alloy, for example, a straight line. Force acts. For this reason, the twist preventing member and the conducting wire can be integrated so that twisting can be reliably eliminated, and signal cable disconnection avoidance and laying removal efficiency can be improved.

  Further, the twist preventing member may be a shield member arranged in a spiral shape that twists in the circumferential direction as it goes in the direction of the axis.

  Since such a shield member acts like a torsion coil spring and the restoring force against torsion acts on the entire signal cable, it is possible to reliably eliminate the twist, avoiding disconnection of the signal cable and improving the efficiency of laying removal work. Can be achieved.

  The twist prevention member may be a line member extending along the axis.

  Such a restoring force due to the elastic deformation of the wire member can automatically eliminate the twist, and it is possible to avoid the disconnection of the signal cable and to increase the efficiency of the laying removal work.

  According to the signal cable of the present invention, the torsion member and the conductor are integrated, and the restoring force by the torsion prevention member acts, so that the twist can be automatically eliminated. As a result, it is possible to avoid disconnection and increase the efficiency of laying / removing work.

It is a schematic sectional drawing which shows the signal cable which concerns on 1st embodiment of this invention. In the signal cable which concerns on 1st embodiment of this invention, it is a schematic sectional drawing which shows the case where arrangement | positioning of a shape memory alloy differs. It is a schematic sectional drawing which shows the signal cable which concerns on 2nd embodiment of this invention, Comprising: (a) is whole sectional drawing, (b) shows the arrow A of (a). It is a schematic sectional drawing which shows the signal cable which concerns on 3rd embodiment of this invention.

Hereinafter, the signal cable 1A according to the embodiment of the present invention will be described.
The signal cable 1A is a measurement cable used for various measuring instruments such as pressure measurement and vibration measurement in a gas turbine or a steam turbine, for example.

  As shown in FIG. 1, the signal cable 1A includes two conductors 10 for transmitting signals, a shield wire 12 that covers the entire two conductors 10 from the outside, and a shape memory alloy plate (twisted) that further covers the shield wire 12 from the outside. Prevention member) 11 and a cover 13 covering all of these from the outside.

  The conducting wire 10 is a transmission line having a circular cross section made of copper or the like extending along the axis P, and performs signal transmission in the various measuring instruments. In the present embodiment, a two-core cable in which two conductive wires 10 are arranged in parallel is provided.

  The shield wire 12 is made of a thin conductive wire 10 knitted in a net shape or a metal foil or the like, and is a member that covers the whole of the two conductive wires 10 from the outside, and generates electrostatic induction in the conductive wire 10 due to external static electricity. It is an electrostatic shield that prevents The shield wire 12 has an elliptical cross section by covering the two conducting wires 10 having a circular cross section from the outside in the radial direction of the axis P.

  The cover 13 is made of polyvinyl chloride, fluororesin, or the like, and is disposed on the outermost side of the signal cable 1A so as to hold the shape memory alloy plate 11 between the shield wire 12 and the outer side in the radial direction of the axis P. It is what is done. The cover 13 is provided so as to restrict relative rotation between the cover 13 and the shape memory alloy plate 11.

Next, the shape memory alloy plate 11 will be described.
The shape memory alloy plate 11 is a plate-like member made of an alloy material having a property of naturally returning to a previously memorized shape when deformation is applied, and is outside the shield wire 12, that is, in the shield wire 12. It arrange | positions at the radial direction outer side of the axis P, and is extended in the axis P direction.

  Further, in the present embodiment, a total of four shape memory alloy plates 11 are provided vertically and horizontally with the axis P therebetween. When these shape memory alloy plates 11 are viewed from the direction of the axis P, the four shape memory alloy plates 11 form a quadrangle, and each side of the quadrangle is on the circumference of the shield wire 12 having an elliptical cross section. Arranged in contact with each other, the relative rotation between the shield wire 12 and the shape memory alloy plate 11 can be restricted.

  According to such a signal cable 1 </ b> A, the shield wire 12 has an elliptical cross section, and the shape memory alloy plate 11 and the conductive wire 10 are in contact with the circumference of the shield wire 12 on each side of the shape memory alloy plate 11. Relative rotation between the two is restricted. Furthermore, relative rotation is also restricted between the cover 13 and the shape memory alloy plate 11, that is, relative rotation between the conductor 10, the shield wire 12, the shape memory alloy plate 11, and the cover 13 is restricted.

  Therefore, when the signal cable 1A is twisted, the shape memorized in the shape memory alloy plate 11 in advance as a whole in the conductor wire 10, the shield wire 12, the shape memory alloy plate 11, and the cover 13, for example, A restoring force acts so as to return naturally to a straight state, and the twist can be automatically eliminated.

  In the signal cable 1A of this embodiment, the lead wire 10, the shield wire 12, the shape memory alloy plate 11, and the cover 13 can be integrated to eliminate twisting, and disconnection of the signal cable 1A caused by twisting can be avoided. Further, when the signal cable 1A is wound around the cable reel, the signal cable 1A can be prevented from being entangled, and the efficiency at the time of laying and removing the cable can be achieved.

  In the present embodiment, four shape memory alloy plates 11 are provided symmetrically in the vertical and horizontal directions across the axis P, but the number is not limited to four, for example, one to restrict relative rotation. You may adhere and fix to the shield wire 12, and you may install only two adjacent in the circumferential direction. Further, as shown in FIG. 2, when viewed from the direction of the axis P, three shape memory alloy plates 11 may form a triangle so as to cover the shield wire 12. For example, in the case of a four-core cable in which these four-core cables are twisted in advance and are arranged in a spiral shape, it is considered that it is more effective to hold these three shape memory alloy plates 11.

  Moreover, although the shape memory alloy plate 11 demonstrated the case where plate shape was made, a block shape may be sufficient, for example, and a shape will not be limited if relative rotation between the shield wires 12 can be controlled.

  Further, a resin or the like may be filled between the cover 13 and the shape memory alloy plate 11 to securely fix and hold the shape memory alloy plate 11 inside the cover 13.

  The shape memory alloy plate 11 may be securely fixed to the outer periphery of the shield wire 12 by adhesion or the like.

Next, the signal cable 1B according to the second embodiment will be described.
In addition, the same code | symbol is attached | subjected to the component similar to 1st embodiment, and detailed description is abbreviate | omitted As shown in FIG. 3, the signal cable 1B of this embodiment is the shape memory alloy plate of 1st embodiment. Instead of 11, an outer shield wire (twist prevention member) 21 is provided.

  The outer shield wire 21 is a shield member made up of a plurality of thin conductors like the shield wire 12 and is formed in a spiral shape so that these thin conductors are twisted from one circumferential side to the other side in the direction of the axis P. Thus, the shield wire 12 is covered from the outside in the radial direction of the axis P. The outer shield wire 21 is thicker than the shield wire 12.

  Further, the outer shield wire 21 is in close contact with the shield wire 12 and restricts relative rotation between them, and is supported from the outside by the cover 13, and relative rotation with the cover 13 is also restricted.

  According to such a signal cable 1B, twist is caused by using the signal cable 1B. At this time, since the outer shield wire 21 is formed in a spiral shape from one side in the circumferential direction to the other side, the outer shield wire 21 acts like a coil spring and twists from one side in the circumferential direction to the other side. Alternatively, a restoring force acts on the signal cable 1B against a twist from the other side in the circumferential direction to the one side. Since the relative rotation among the lead wire 10, the shield wire 12, the outer shield wire 21, and the cover 13 is restricted, this restoring force acts on the entire signal cable 1B and automatically twists the signal cable 1B. It can be solved.

  In the signal cable 1B of the present embodiment, the twisting can be automatically eliminated by integrating the lead wire 10, the shield wire 12, the outer shield wire 21, and the cover 13 by the restoring force of the outer shield wire 21, and the signal cable generated by the twist. 1B disconnection avoidance and efficiency in laying and removing the signal cable 1B can be achieved.

Next, the signal cable 1C according to the third embodiment will be described.
In addition, the same code | symbol is attached | subjected to the component similar to 1st embodiment, and detailed description is abbreviate | omitted As shown in FIG. 4, 1 C of signal cables of this embodiment are the shape memory alloy plates of 1st embodiment. Instead of 11, a piano wire (twisting prevention member) 31 is provided.

  The piano wires 31 are linear members extending along the direction of the axis P, and four are provided on the outer periphery of the cover 13 with a certain interval in the circumferential direction of the cover 13. The piano wire 31 is fixed on the outer periphery of the cover 13 with a certain interval in the direction of the axis P, and restricts relative rotation with the cover 13.

  According to such a signal cable 1C, the relative rotation among the lead wire 10, the shield wire 12, the cover 13, and the piano wire 31 is prevented, so that the restoring force due to the elastic deformation of the piano wire 31 is reduced. The twist can be automatically eliminated.

  In the signal cable 1C of the present embodiment, the twisting can be automatically eliminated by integrating the lead wire 10, the shield wire 12, the cover 13, and the piano wire 31 by a restoring force due to elastic deformation of the piano wire 31, and a signal generated by the twisting. It is possible to achieve disconnection avoidance of the cable 1C and efficiency in laying / removing the signal cable 1C.

  In addition, about the thickness of the piano wire 31, the number, etc., it can change suitably according to the thickness etc. of the signal cable 1C.

  In addition, a metal wire such as a shape memory alloy wire or another linear member may be used in place of the piano wire 31, but in this case, the member will not be disconnected when a twist occurs. It is necessary to select a member in consideration of the balance between the elasticity and rigidity of the member.

The embodiment of the present invention has been described in detail above, but some design changes can be made without departing from the technical idea of the present invention.
For example, in the above-described embodiment, the signal cable 1C has been described as a measurement cable used for various measuring instruments such as pressure measurement and vibration measurement in a gas turbine or a steam turbine. For example, the signal cable 1C is used for an acoustic device such as a headphone or a speaker. Cable may be used.

DESCRIPTION OF SYMBOLS 1A ... Signal cable, 10 ... Lead wire, 11 ... Shape memory alloy plate (twist prevention member), 12 ... Shield wire, 13 ... Cover, 1B ... Signal cable, 21 ... Outer shield wire (twist prevention member), 1C ... Signal cable 31 ... Piano wire (twisting prevention member), P ... Axis

Claims (4)

A conducting wire extending along the axis;
A twist-preventing member that holds the conducting wire inside such that the relative rotation of the conducting wire around the axis can be restricted, and that generates a restoring force on the other circumferential side when twisted to one circumferential side of the axis. A signal cable characterized by   The signal cable according to claim 1, wherein the twist preventing member is a shape memory alloy extending along the axis.   The signal cable according to claim 1, wherein the twist preventing member is a shield member disposed in a spiral shape that twists in a circumferential direction toward the axis.   The signal cable according to claim 1, wherein the twist preventing member is a line member extending along the axis.

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