JP2007298382A - Detector for element wire breakage in vibration test of stranded wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detector for detecting element wire breakage in a vibration test for a stranded wire, capable of detecting surely a disconnection of the element wire in the stranded wire. <P>SOLUTION: This detector for the element wire breakage of carrying out the vibration test for the stranded wire, under the condition where a tensile force is applied all the time onto the stranded wire comprising only the element wires, includes a tensile force applying device for applying the tensile force onto the stranded wire 1, a strain gage 4 bonded onto at least one out of the element wires 5 in the stranded wire 1, a strain gage bridge converter 6 connected to the strain gage 4, and a determination device 8 connected to the strain gage bridge converter 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for detecting a broken wire in a strand vibration test.

A stranded wire such as a power supply line for a railway is composed of a thin strand. Therefore, when conducting a strand vibration test, it is necessary to confirm in advance whether or not there is any breakage of the strand. Conventionally, whether the strand is broken or not by monitoring with a camera. I was going to check.
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  In particular, when performing a vibration test of a single wire such as a trolley wire, if the trolley wire is vibrated when the trolley wire is broken, the fitting that holds the trolley wire moves to operate the switch. Stop the testing machine.

  However, in the case of a stranded wire, even if one strand breaks, even if the strength of the entire wire is reduced, the chuck portion does not move, so it is impossible to detect that the strand within the strand is broken.

  In view of the above situation, an object of the present invention is to provide a strand break detection device in a strand vibration test that can reliably detect a break in a strand in a strand.

In order to achieve the above object, the present invention provides
[1] A tensile force application device for applying a tensile force to a stranded wire in a strand breakage detecting device for performing a strand vibration test in a state where a tensile force is always applied to the stranded wire composed of only a strand. A strain gauge attached to at least one of the strands in the strand, a strain gauge bridge converter connected to the strain gauge, and a determiner connected to the strain gauge bridge converter. It is characterized by that.

  [2] In the strand breakage detecting device in the strand vibration test described in [1] above, the tensile force of the tensile force applying device can be adjusted, and the strands in the strand under various tensile forces It is characterized by detecting a disconnection.

  [3] In the strand break detection device in the strand vibration test described in [1] or [2], an output amplifier is provided between the strain gauge bridge converter and the determination device. .

  According to the present invention, the following effects can be achieved.

  (1) It is possible to accurately detect the disconnection of the strands in the line.

  (2) By adjusting the tensile force applied to the strands, it is possible to detect disconnection of the strands in the strands under various tensile forces.

  The strand break detection device in the strand vibration test of the present invention is a strand strand break detection device that performs a strand vibration test in a state where a tensile force is always applied to the strand composed of only the strand. 2 includes a tensile force applying device that applies a tensile force to the stranded wire, a strain gauge that is attached to at least one of the strands in the stranded wire, and a determination device that is connected to the strain gauge.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a schematic diagram of a vibration testing machine having a strand breakage detecting device in a strand vibration test showing an embodiment of the present invention, and FIG. 2 is a diagram showing an example of an output signal of a strain gauge of the detecting device.

In this figure, 1 is a stranded wire, 2 is a fixing portion (stranded wire gripping portion) for fixing the stranded wire 1, and 3 is a chuck provided at the tip of the stranded wire 1 to which a constant tensile force F is applied. Is a strain gauge attached to at least one strand 5 in the strand 1, 6 is a strain gauge bridge converter connected to the strain gauge 4, and 7 is an output connected to the strain gauge bridge converter 6. An amplifier 8 is a determination unit connected to the output amplifier 7. Here, when the stranded wire 1 is, for example, a hard stranded aluminum wire, the nominal cross-sectional area is 200 (mm ² ), the strand diameter is 3.7 mm, the number of strands is 19, and the strand outer diameter is 18.5 mm. In the case of a stranded wire, the nominal cross-sectional area is 38 (mm ² ), the strand diameter is 2.6 mm, the number of strands is 7, and the stranded wire outer diameter is 7.8 mm. mm ^2), wire diameter 4.0 mm, wire number seven, is more Sengai径12.0 mm.

Further, as the strain gauge 4, for example, as shown in FIG. 3, a one-active gauge method (2-wire type) is used. Here, the strain of the strain gauge bridge (converter) 6 output is
The output voltage (e) of the bridge is e = (1/4) · Ks · E · ε
Where Ks: strain gauge gauge factor
E: Bridge voltage
ε: Strain Therefore, a tensile force F is applied to the chuck 3 and a constant tensile force is applied to the stranded wire 1 to vibrate. At that time, since the strain gauge 4 is affixed to the strands 5 of the strands 1, the steady vibration, the output V ₁ of the strain gauge bridge converter 6 in strand 5 which corresponds to the constant strain (Fig. 2 Reference) is obtained. In addition, f in FIG. 2 is a vibration repetition frequency.

  When the strands in the strands break, the following state occurs.

(1) When the strand 5 in the wire 1 is broken, no tensile force is applied to the strand 5, so the output V ₂ of the strain gauge bridge converter 6 becomes zero. Naturally, if a strain gauge is attached to each of the strands, it is possible to accurately detect which strand is broken.

(2) When the strands other than the strand 5 in the wire 1 are broken, the tensile force applied before the break is dispersed to the unbroken strands. That is, since the tensile force applied to the broken wire is borne by the other wires including the wire 5, the wire 5 is pulled as much as about one healthy wire portion of the load. Power will increase. Therefore, the output V ₃ (output V ₃ > output V ₁ ) of the strain gauge bridge converter 6 is applied.

  As described above, the distortion of the unbroken element wire is slightly increased, and an output ΔV corresponding to the slightly increased distortion is obtained. This output ΔV is determined by the determiner 8, and the vibration tester is stopped.

  As is clear from the above, the breakage of the strands in the strands can be detected by attaching a strain gauge to at least one of the plurality of strands.

  Thus, when a strain gauge is attached to at least one of the plurality of strands, there is an advantage that the number of strain gauges and the number of wirings can be reduced. However, it is necessary to provide a strain gauge bridge converter and an output signal amplifier having high accuracy.

  When attaching strain gauges to all the wires, it is only necessary to determine whether the output V of the strain gauge is “1” or “0”. Therefore, a high-performance strain gauge bridge converter and output amplifier can be used. Although there is an advantage that it is not necessary to use it, the strain gauge and its wiring increase, and it takes time and effort for construction.

  FIG. 4 is a schematic view of a vibration testing machine having a strand breakage detecting device in a strand vibration test showing another embodiment of the present invention.

  In this figure, 11 is a stranded wire, 12 is a fixing portion (stranded wire gripping portion) for fixing the stranded wire 11, 13 is a chuck provided at the tip of the stranded wire 11, and 14 applies a tensile force to the chuck 13. A tensile force application device, 15 is a tensile force adjustment device that adjusts the tensile force of the tensile force application device 14, 16 and 17 are strain gauges that are attached to different strands 18 and 19 in the strand 1, and 20 is A strain gauge bridge converter connected to the strain gauges 16 and 17, 21 is an output amplifier connected to the strain gauge bridge converter 20, and 22 is a determiner connected to the output amplifier 21.

  In this embodiment, by adjusting the tensile force of the tensile force applying device 14 by the tensile force adjusting device 15, the vibration test of the stranded wire under various tensile forces can be performed. The disconnection of the strands of the strands can be reliably detected.

  In addition, since two strain gauges are provided and attached to different strands, even if one strain gauge is broken, it can be backed up with another strain gauge. There are advantages you can do.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The strand breakage detection device in the strand vibration test of the present invention can be used as a tool for reliably detecting the breakage of a strand of a feeder line composed of a stranded wire such as a railway feeder line.

It is a schematic diagram of the vibration testing machine which has the detection apparatus of the strand break in the strand vibration test which shows the Example of this invention. It is a figure which shows the example of an output signal of the strain gauge of the strand breakage detection apparatus in the strand vibration test which shows the Example of this invention. It is a figure which shows the strain gauge bridge converter of the detection apparatus of the strand break in the strand vibration test which shows the Example of this invention. It is a schematic diagram of the vibration testing machine which has the detection apparatus of the strand break in the strand vibration test which shows the other Example of this invention.

Explanation of symbols

1,11 Stranded wire 2,12 Fixed part (Stranded wire gripping part)
3,13 Chuck 4,16,17 Strain gauge 5,18,19 Wire 6,20 Strain gauge bridge converter 7,21 Output amplifier 8,22 Judgment device 14 Tensile force application device 15 Tensile force adjustment device

Claims (3)

In a strand breakage detecting device for conducting strand vibration test in a state in which a tensile force is always applied to the strand consisting only of strands,
(A) a tensile force application device that applies a tensile force to the stranded wire;
(B) a strain gauge attached to at least one of the strands in the strand;
(C) a strain gauge bridge converter connected to the strain gauge;
(D) An apparatus for detecting a broken wire in a strand vibration test, comprising: a determination device connected to the strain gauge bridge converter.   2. The apparatus for detecting a broken wire in a strand vibration test according to claim 1, wherein the tensile force of the tensile force applying device can be adjusted to detect breakage of the strand in the strand under various tensile forces. An apparatus for detecting a broken wire in a vibration test of a stranded wire.   The strand breakage detecting device in the strand vibration test according to claim 1 or 2, further comprising an output amplifier between the strain gauge bridge converter and the determination device. Wire breakage detection device.

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