JP3459990B2 - Cable sensor and its mounting method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable sensor for measuring displacement of an object to be measured such as rock fall or rock collapse.

[0002]

2. Description of the Related Art Conventionally, it has not been possible to accurately predict rock fall such as rock fall or rock collapse. For this reason, safety measures were taken by installing protective fences at locations where there is a risk of falling.

[0003]

<A> The present invention is to easily detect the displacement of the object to be measured. <B> The present invention is to easily detect displacement of rocks or the like that may be dropped.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in a cable sensor for detecting displacement of an object to be measured, a tension portion of an optical cable to which tension force is applied in contact with the object to be measured and both ends of the tension portion are fixed. A set of fixing members for fixing to an object and a B-OTDR measuring device attached to an optical cable are provided, and the tension part is arranged so as to partially surround the object to be measured.
Tension so that tension is applied to the tension part when the fixed object moves.
The part is fixed between the fixed object and the fixed object rotatably with a fixing member
Then, the B-OTDR measuring device measures the change in tension of the tension part.
Then , in the cable sensor, or the cable sensor for detecting the displacement of the measured object, which is characterized in that the magnitude of the displacement of the measured object is obtained, the tensioned portion of the cable to which tension is applied, and the tensioned portion of the cable. Fixing member that fixes one end to the fixed object, and B-OTDR measurement attached to the optical cable
Equipped with a container , the tension is applied to the tension part when the measured object moves
The tension part between the measured object and the fixed object
It is rotatably fixed with a member and the B-OTDR measuring device is strained.
The change in tension of the part is measured and the magnitude of displacement of the measured object is measured.
In the method of mounting the cable sensor, or the cable sensor for detecting the displacement of the object to be measured, which is characterized in that it is arranged so as to partially surround the object to be measured by the tension part of the optical cable, and the object to be measured moves. , Tension is applied to the tension part
Tension part so that it is applied between the fixed object and the fixed member
Rotatably fixed with an optical cable and B-OTDR measuring instrument
Is attached, and when the measured object moves, tension is applied to the tension part.
Then, the displacement of the measured object is measured by the B-OTDR measuring device.
In the method for mounting the cable sensor, or the method for mounting the cable sensor for detecting the displacement of the measured object , the measured object is
When moving, tension is applied to the tension part so that the optical cable
The tensioned part of the
Fixed in place and attached B-OTDR measuring device to the optical cable
When the measured object moves, tension is applied to the tension part ,
A cable sensor mounting method is characterized in that the magnitude of displacement of an object to be measured can be measured by a B-OTDR measuring device .

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

<A> Cable sensor The cable sensor 1 is configured such that the optical cable 3 is brought into contact with the object 6 to be measured, such as rock, and is locked or fixed to the object 6 to be measured.
It is for detecting that the measured object 6 moves and is displaced. As shown in FIG. 1, for example, the cable sensor 1 contacts the object to be measured 6 with the tension portion 31 of the optical cable 3 and locks the both ends, and both ends of the tension portion 31 are fixed to the fixed object 61 via the fixing members 2. . When the measured object 6 moves, that is, is displaced,
The tension applied to the tension portion 31 of the optical cable 3 changes, and the strain of the optical cable 3 at that portion is measured, whereby the displacement of the measured object 6 can be measured. The optical cable 3 of the tension part 31 of the cable sensor 1 is connected to the temperature correction part 32.
Is connected in series with the optical cable 3, and the final end of the one end is connected to the detection device 4 capable of measuring the strain of the optical cable. Between the cable sensor 1 and the detection device 4, if necessary, five devices such as other cable sensors that use an optical cable are connected. Optical cable 3 of cable sensor 1
The other end of is connected to the device 5 using another optical cable as needed. In this way, a device 5 using an optical cable such as a large number of cable sensors in the middle of the optical cable 3
Can be connected. The cable sensor 1, the device 5 using the optical cable, or the detection device 4 are connected by the connecting portion 33 of the optical fiber. The tension part 31 and the temperature correction part 32 of the optical cable 3
Is attached to the object to be measured with a locking tool 62, for example, as shown in FIG. As the locking tool 62, for example, an all plug of a stainless steel saddle is used. Here, the fixed object 61 means an object that does not move integrally with the measured object 6 such as the ground.

The cable sensor 1 can also be mounted as shown in FIG. One end of the cable sensor 1 is
It is fixed to the measured object 6 via the fixing member 2, and the other end of the cable sensor 1 is fixed to the fixed object 61 via the fixing member 2.

<B> Fixing member The fixing member 2 is for fixing the tension portion 31 of the optical cable 3 to the measured object 6 or the fixed object 61, as shown in FIGS. 3 to 4, for example. According to the structure of taking in and taking out to the outside, it can be divided into a first fixing member and a second fixing member as needed. FIG. 3 (A) is a plan view of the fixing member 2, and FIG. 3 (B) is a side view thereof. FIG. 4 (A) is a plan view of another fixing member 2, and FIG. 4 (B) is a side view thereof.

The first fixing member is a fixing member having an optical cable entry / exit portion 23 which comes from the outside and goes out to the outside. First
The fixing member includes the container 21 and the container 6 to be measured or the fixed object 6.
The fixing jig 26 for fixing to No. 1 is provided. Fixing jig 26
Is fixed to the measured object 6 or the fixed object 61 by an anchor or the like.

A length adjusting jig 24 for adjusting the length and a rotatable jig 25 for freely rotating are arranged between the container 21 and the fixing jig 26, if necessary. The rotatable jig 25 enables refraction in the axial direction or rotation around the axis. The container 21 is provided with a fixing portion 22 for fixing the optical cable 3 and an optical cable inlet / outlet portion 23 for taking in the optical cable 3 from the outside and taking it out. The fixing portion 22 is preferably one that does not give unnecessary distortion to the optical cable 3, and is, for example, a cylindrical or elliptic cylindrical fixing tool 221, and the optical cable 3 is wound around the cylindrical fixing tool 221 and fixed. Alternatively, the fixed portion 22 is the optical cable 3
And the optical cable 3 is clamped by the fastener 222 and fixed. The fastener 222 is made of a plate to which an elastic material such as rubber is attached, and the optical cable 3 is sandwiched between the plates and fastened with a screw or the like to fix it.

The second fixing member may be the same as the first fixing member without the optical cable entry / exit portion 23, and fixes the tension portion 31 of the optical cable 3 and the end portion of the temperature correction portion 32,
To hold. The first fixing member and the second fixing member are made to have the same shape by making the tensioning portion 31 and the temperature correction portion 32 folded back in a multiple manner and locking the object to be measured differently from FIGS. 1 and 2. You can also do it. Or
Both ends of the tension part 31 and the temperature correction part 32 are fixed to one fixing member 2.
It is also possible to fix and hold the first fixing member and the second fixing member with the same fixing member.

<C> Optical cable The optical cable 3 includes one coated optical fiber core wire 34.
And the support line 35 are integrally formed in parallel. For example, as shown in FIG. 5, the cross section of the optical cable 3 has a daruma shape in which two circles are connected by a neck portion. Optical fiber core 3
4 is covered with a high-tensile fiber and further covered with a sheath 36, a support wire 35 is covered with a sheath 36, and the optical fiber core wire 34 and the support wire 35 are integrally joined by a sheath 36. When it is used as the tension portion 31, the supporting wire 35 at that portion is cut and removed. Even when it is used as the temperature correction unit 32, the support wire 35 at that portion may be cut and removed. The portion of the optical fiber core wire 34 and the portion of the support wire 35 can be easily separated from the neck portion 37.

As the optical fiber core wire 34, for example, the cable structure shown in Table 1 can be used, the transmission characteristics shown in Table 2 can be used, and the mechanical characteristics shown in Table 3 can be used. it can.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

<D> Arrangement of Optical Cable The optical cable 3 is taken in from the optical cable inlet / outlet portion 23 of the container 21 of the first fixing member. The supporting line 35 of the optical cable is removed from this portion. The optical cable 3 is wound around the fixing portion 22 and fixed, and taken out to the outside of the container 21 as the tension portion 31. In FIG. 1, the tension part 31 is brought into contact with and locked around the object 6 to be measured, and the other end is put in the container 21 of the second fixing member 2 and wound around the fixing part 22 to be fixed. The tension part 31 is shown in FIG.
Then, the other end is put in the container 21 of the second fixing member 2 and the fixing portion 2
It is wound around 2 and fixed, and the second fixing member 2 is fixed to the measured object 6.

The optical cable 3 is protected by a flexible tube 38 having flexibility for protection and friction reduction. The flexible tube 38 protects the optical cable 3 entering the fixing member 2 from the outside and coming out of the fixing member 2, and the tension portion 31 and the temperature correction portion 3 are also protected.
2 is also protected by the flexible tube 38. Tension part 31 and temperature correction part 3
Since 2 can move freely inside the flexible tube 38, even if the flexible tube 38 is fixed to the object to be measured, for example, the tension portion 31.
The temperature correction unit 32 is not fixed to the measured object.

The other end of the tension part 31 is connected in series to one end of the temperature correction part 32, and is taken out of the container 21 of the second fixing member as the temperature correction part 32. Temperature correction unit 32
Is arranged without strain, for example, along the tension portion 31, and the other end is held by the container 21 of the first fixing member. The optical cable 3 of the temperature correction unit 32 is taken out from the optical cable inlet / outlet unit 23 to the outside. The tension section 31
Alternatively, the temperature correction unit 32 may be folded back between the first fixing member and the second fixing member and a plurality of the temperature correcting units 32 may be arranged.

<E> As shown in FIG. 1, the measurement / detection device 4 using a cable sensor is connected to one end of the optical cable 3, transmits an optical signal, and receives a reflected wave returned from the optical cable 3, thereby As shown in FIG. 6, it is possible to measure the strain of the specific portion of the optical cable 3, that is, the strain of the tension portion 31 and the temperature correction portion 32. Even if a plurality of cable sensors 1 are connected in series or a device 5 using another optical cable is connected in series, the cable sensor 1 can be specified from the strain measurement position 4.

When the object 6 to be measured moves, the tension of the tension portion 31 of the cable sensor 1 locked therein changes, and the strain of the optical cable changes as shown in FIG. As a result, the position of the cable sensor 1 can be specified, and the magnitude of displacement of the measured object 6 can be obtained. The detection device 4
Can use a device that measures the strain of the optical cable 3,
For example, there is a B-OTDR measuring device (AQ8602, manufactured by Ando Electric Co., Ltd.).

When the temperature of the cable sensor 1 changes, the strain of the optical cable 3 of the tension portion 31 changes and the measured value changes, as shown in FIG. Optical cable 3 of temperature correction unit 32
Since the strain also changes, the temperature correction unit 32 can correct the magnitude of the strain of the tension unit 31 from the measured value, and the temperature of the measured value of the cable sensor 1 can be corrected.

[0023]

According to the present invention, the following effects can be obtained. <A> A cable sensor capable of detecting the displacement of the object to be measured can be obtained by effectively utilizing the characteristics of the optical cable. <B> A cable sensor that does not require a power source can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a cable sensor using an optical cable.

FIG. 2 is a schematic diagram of another cable sensor using an optical cable.

FIG. 3 is a structural diagram of a fixing member

FIG. 4 is a structural diagram of another fixing member.

FIG. 5 is a sectional view of the optical cable.

FIG. 6 is a diagram showing distortion of an optical cable.

[Explanation of symbols]

1 ... Cable sensor 2 ... Fixing member 21..container 22 ... Fixed part 221 · Cylinder fixture 222 · Fastener 23..Optical cable entry / exit 24..Jig for length adjustment 25 ... Rotating jig 26..Fixing jig 3 ... Optical cable 31 ... Tension 32 ... Temperature correction unit 33..Connection parts 34 .. Optical fiber core wire 341 / High Tensile Fiber 35 .. Reinforcing wire 36..Sheath 37 ... neck 38 ... Flexible tube 5: Device using other optical cables 6 ... Object to be measured 61..Fixed object 62..Locking tool

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomokazu Shibayama 2-3-1, Kasumigaseki, Chiyoda-ku, Tokyo Metropolitan Bureau of Construction (72) Inventor Hitoshi Takahashi 2-62, Ikeshita-cho, Chikusa-ku, Nagoya, Aichi Prefecture Construction Aichi National Highway Construction Office (72) Inventor Takayuki Motofuji 1-13-8 Aoi, Higashi-ku, Nagoya-shi, Aichi NT TMI Tokai Co., Ltd. (72) Ichiro Okubo Higashi-Kashigaya, Ebina City, Kanagawa Prefecture 5-chome 15-18 Toyoko Hermes Co., Ltd. (56) Reference JP 10-11677 (JP, A) JP 10-197297 (JP, A) JP 11-201735 (JP, A) Special Kaihei 11-316141 (JP, A) JP 2000-46528 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 G01D 21/00-21 / 02 G02B 6/00 E02D 17/00-17/20

Claims (10)

(57) [Claims] 1. A cable sensor for detecting displacement of an object to be measured, comprising: a tension part of an optical cable which is in contact with the object to be tensioned, and a pair of ends for fixing both ends of the tension part to a fixed object. It is equipped with a fixing member and a B-OTDR measuring device attached to the optical cable, and is arranged so that the tension part partially surrounds the measured object.
When the body moves, tension the tension part so that tension is applied to the tension part.
It is rotatably fixed by a fixing member between a fixed object and a fixed object, and the B-OTDR measuring device measures the change in tension of the tension part,
Characterized in that the magnitude of displacement of the measured object is obtained,
Cable sensor. 2. A cable sensor for detecting a displacement of an object to be measured, a tension portion of a cable to which tension is applied, a fixing member for fixing one end of the tension portion to a fixed object, and a B attached to an optical cable. -It is equipped with an OTDR measuring device so that tension is applied to the tension part when the measured object moves.
Then, rotate the tension part between the measured object and the fixed object with the fixing member.
Freely fixed, the B-OTDR measuring device measures the change in tension of the tension part,
Characterized in that the magnitude of displacement of the measured object is obtained,
Cable sensor. 3. The cable sensor according to claim 1 or 2, wherein the fixing member comprises a container having a columnar fixture for fixing the optical cable, and a fixing jig for fixing the container to a fixed object. A cable sensor characterized in that 4. The cable sensor according to claim 1 or 2, wherein the fixing member includes a container having a fastener for sandwiching and fixing the optical cable, and a fixing jig for fixing the container to a fixed object. A cable sensor, which is characterized in that 5. The cable sensor according to claim 4, further comprising a length adjusting jig and a rotatable jig between the container and the fixing jig. . 6. The cable sensor according to claim 1, wherein in the optical cable, one coated optical fiber core wire and a support wire are integrally formed in parallel with each other, and the support wire is removed at least at a tension portion. A cable sensor characterized in that 7. The cable sensor according to claim 6, wherein the optical fiber core wire is covered with a high-tensile fiber, and the high-tensile fiber is covered with a sheath. 8. The cable sensor according to claim 1, wherein the optical cable is protected by a flexible tube having flexibility. 9. A method of mounting a cable sensor for detecting a displacement of an object to be measured, wherein the tensioned part of an optical cable is arranged so as to partially surround the object to be measured, and when the object to be measured moves, tension is applied to the tensioned part. Will be done
The tension part can be freely rotated between the fixed objects with the fixing member
Fixing the optical cable to attach the B-OTDR measurement device, the object to be measured moves, the tension is imparted to the tension unit, B-
A method of mounting a cable sensor, characterized in that the magnitude of displacement of an object to be measured can be measured by an OTDR measuring device . 10. A method of mounting a cable sensor for detecting displacement of an object to be measured, wherein tension is applied to a tension portion when the object to be measured moves.
The optical fiber tension part between the measured object and the fixed object.
Rotatably secured at a fixed member, an optical cable to attach the B-OTDR measurement device, the object to be measured moves, the tension is imparted to the tension unit, B-
A method of mounting a cable sensor, characterized in that the magnitude of displacement of an object to be measured can be measured by an OTDR measuring device .