JP5822158B2 - Displacement measuring device for long materials - Google Patents

Description

  The present invention relates to an apparatus for measuring a displacement amount of a long material such as a guide rail for a fall prevention safety device attached to a steel tower.

  Generally, a guide rail for a fall prevention safety device is attached to the steel tower. When the worker ascends and descends the steel tower, a fall-prevention safety device connected to the operator's waist belt is fitted into the guide rail, and the safety device is slid along the guide rail as the operator moves up and down (Patent Document 1).

  Such a guide rail is usually configured as a series of long rails substantially fixed along the main pillar of the tower, with a plurality of unit rails fixed to an angle member or the like constituting the main pillar of the tower via a mounting bracket. . Each unit rail is linear at the time of shipment, but is distorted when attached to the main pillar of a steel tower, and often has a wavy shape as a series of guide rails. This is because the main pillar is usually composed of overlapping angle materials, so even if the rail is mounted with the same mounting bracket, the rail swells, and further, when mounting each mounting bracket to the main pillar, This is because the rail also swells due to the deviation (error).

Japanese Patent Laid-Open No. 2002-095763 FIG.

  If the waviness of this guide rail can be measured accurately, the strain (initial strain) when each unit rail is attached to the steel tower can be accurately grasped, and this can be used to predict the life of the guide rail. However, a technique for measuring swell of a long material simply and accurately has not been established.

  The present invention has been made in view of the above circumstances, and one of its purposes is an apparatus for measuring a displacement amount of a long material that can easily and accurately measure the swell of the long material such as the guide rail. Is to provide.

  The apparatus for measuring the amount of displacement of a long material according to the present invention includes a constant speed traveling unit, a gantry, an accelerometer, and a recorder. The constant speed traveling unit travels at a constant speed along a long material extending in the vertical direction. The gantry is moved along the long material together with the constant speed traveling portion. The accelerometer is an accelerometer that measures acceleration in the plane direction of the gantry, and measures an acceleration component of gravity generated in the plane direction of the gantry tilted according to the undulation of the long material. The recorder records the measurement result of the accelerometer.

  When the constant speed traveling unit is traveled along the long body, the gantry can be traveled in synchronization with the constant speed traveling unit. At this time, since the gantry is inclined according to the undulation of the long body, an acceleration component of gravity is generated in the plane direction of the gantry. If this acceleration component is measured by an accelerometer and the measurement result is recorded in a recorder, the displacement amount of the long body, that is, the undulation can be obtained by using this measurement result and the traveling speed of the constant speed traveling unit. It can be obtained by calculation.

  In the displacement measuring apparatus for a long material according to the present invention, it is preferable that the constant-speed traveling unit and the gantry are members independent from each other, and a suspension member that suspends the gantry from the constant-speed traveling unit is provided.

  The constant-speed traveling unit and the gantry are made into separate members, and the gantry is suspended from the constant-speed traveling unit with a suspension material, so that vibration caused by the traveling of the constant-speed traveling unit is directly transmitted to the gantry, and the accelerometer Suppresses the detection of vibrations that are not based on the undulations of the long body.

  In the apparatus for measuring displacement of a long material according to the present invention, the accelerometer is preferably a servo accelerometer.

  A servo-type accelerometer is easy to detect low-frequency vibrations, and is suitable for accurately detecting the acceleration component of gravity caused by the tilt of the gantry accompanying the swell of the long body.

  In the apparatus for measuring a displacement amount of a long material according to the present invention, a pair of the accelerometers are provided, and each accelerometer measures an acceleration component of gravity caused by the inclination of the gantry with respect to the horizontal direction and the horizontal direction. It is preferable that it is attached to the mount.

  By detecting the acceleration component of gravity associated with the inclination of two plane directions orthogonal to each other in the front-rear direction and the left-right direction of the gantry, it is possible to detect the undulation in the front-rear direction and the left-right direction of the long body. Therefore, the undulation of the long body can be grasped in three dimensions.

  The long material displacement measuring apparatus of the present invention preferably includes a power supply for the accelerometer and a recorder for the measurement result of the accelerometer.

  By providing a power source, an accelerometer that requires a power source such as a servo accelerometer can be used, and by providing a recorder, the acceleration component of gravity measured by the accelerometer can be reliably recorded. .

  In the apparatus for measuring displacement of a long material according to the present invention, it is preferable that the constant-speed traveling unit is a fall prevention safety device that descends along the long material.

  The fall prevention safety device includes a type in which the safety device is gradually lowered along the guide rail at a constant speed when an operator crashes. This type of fall prevention safety device can be used as it is as a constant speed traveling unit.

  In the displacement measuring apparatus for a long material according to the present invention, the long material may be a guide rail of a fall prevention safety device attached to a steel tower.

  The guide rail of the fall-preventing safety device is suitable as a long body to be measured for displacement. By measuring the amount of displacement, the measurement result can be used to predict the life of the guide rail.

  According to the displacement measuring apparatus for a long material of the present invention, the displacement (swell) of the long body can be easily and accurately measured by running the apparatus of the present invention at a constant speed along the long body. it can.

1 is a schematic configuration diagram of a displacement amount measuring apparatus according to Embodiment 1. FIG. (A) is a perspective view of a guide rail that is an example of a displacement amount measurement target, and (B) is a schematic view showing a state in which the rail is attached to a steel tower. FIGS. 2A and 2B are explanatory views showing the measurement principle of the apparatus of FIG. 1, in which FIG. 1A shows a state in which the gantry is kept horizontal, FIG. 1B shows a state in which the gantry is tilted, and FIG. The displacement x of the guide rail at y is shown. 5 is a model diagram of a measurement target of a displacement amount in Test Example 1. FIG. Each of (A) to (C) is a graph showing measurement results of guide rails having different displacement amounts in Test Example 1. The correlation between the measured value and the measured value in Test Example 1 is shown, (A) is a correlation graph of values in the left-right direction, and (B) is a correlation graph of values in the front-rear direction. The displacement amount measurement method in Test Example 2 is shown, (A) is an explanatory diagram of continuous measurement, and (B) is an explanatory diagram of divided measurement. 10 is a graph showing an example of measurement results of continuous measurement in Test Example 2. Examples of comparison results of continuous measurement and split measurement in Test Example 2 are shown. (A) and (C) are graphs showing the measurement results of continuous measurement, and (B) and (D) are graphs showing the measurement results of split measurement. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, the displacement measuring device of the present invention will be described by taking as an example the case where the amount of displacement of a guide rail provided along the main pillar of a steel tower, that is, the amount of displacement with respect to a straight line connecting two points along the guide rail is measured. In each figure, the same code | symbol is attached | subjected to the common member.

[Embodiment 1]
{Overview}
As shown in FIG. 1, the displacement amount measuring apparatus includes a constant speed traveling unit 1, a gantry 2, an accelerometer 3, and a recorder 4. In addition, the apparatus of this example includes a power source 5, a suspension member 6, and a displacement amount calculation means 7. The gantry 2 descends the guide rail R at a constant speed together with the constant speed traveling unit 1, and is tilted according to the swell of the rail R at that time. The acceleration component of gravity generated in the plane direction of the gantry 2 due to this inclination is measured by the accelerometer 3, and the result is recorded by the recorder 4. On the other hand, as shown in FIG. 2, the guide rail R is composed of a unit-length unit rail having an I-shaped cross section, and is configured by arranging a plurality of unit rails in series. This rail R is a belt-like support piece R2 gripped by a mounting bracket F fixed to the main pillar P of the steel tower ST, and a belt-like shape in which a number of fitting holes RH are arranged in parallel in the longitudinal direction so as to face the support piece R2. And a strip-shaped connecting piece R3 that is orthogonal to the supporting piece R2 and the traveling piece R1 and connects the two pieces R1 and R2. In the following description, the support piece R2 side of the guide rail R is the rear (rear side), the travel piece R1 side of the guide rail R is the front (front side), and both sides viewed from the front are left and right. However, the vertical direction does not necessarily need to coincide with the vertical direction, and includes the extending direction as long as it extends substantially in the vertical direction. This is because the steel tower ST usually has a portion where the main pillar P is inclined so as to taper upward, and the guide rail R along the main pillar P does not coincide with the vertical direction.

{Constant running section}
The constant speed traveling unit 1 is a mechanism that can move along the guide rail R at a constant speed. The traveling section is not particularly limited as long as it can move along the guide rail R at a constant speed, and particularly descend.

  In this example, a crash prevention safety device “High Throw” (trade name) manufactured by Sumiden Asahi Seiko Co., Ltd. is used as the constant speed traveling unit 1 (see FIG. 11 of JP 2002-95763 A). The outline is as follows. The safety device includes a main body in which a box-shaped block portion and a plate-shaped plate portion are connected by a connecting shaft, a sprocket that is rotatably supported by the main shaft between the two portions, and a governor. At the time of ascent, the safety device is attached to the guide rail R and pulled up by the operator, thereby sliding the main body along the guide rail R while sequentially fitting the teeth of the sprocket into the fitting holes of the traveling piece R1. At the time of the crash, the safety device keeps the sprocket rotation speed constant by the governor and descends at a gentle constant speed to prevent the worker from dropping suddenly. Further, the safety device includes a stopper that stops the safety device at an arbitrary position on the guide rail R, and the safety device can be lowered at a moderate constant speed by releasing the stopper. Therefore, with this safety device, the constant speed traveling unit 1 can be easily run / stopped by the action / inaction of the stopper without any particular design change.

{Frame}
The gantry 2 is a support for mounting main constituent members other than the constant speed traveling unit 1 among the constituent members of the device of the present invention. In this example, the gantry 2 is a metal box that has upper and lower upper and lower surfaces, left and right side surfaces, and a rear surface, and has an open front. A power source 5 to be described later is housed in the gantry 2 and an accelerometer 3 and a recorder 4 are mounted on the upper surface. If the gantry 2 is open at the front, the cable connecting operation for connecting the mounting members to the gantry 2 can be easily performed.

  The gantry 2 includes a fitting portion for the guide rail R. In this example, a guide roller that holds the traveling piece R1 of the guide rail R from both sides is provided on the back surface of the gantry 2 as the fitting portion. By this fitting portion, not only the constant speed traveling portion 1 but also the gantry 2 always travels along the guide rail R, and the gantry 2 is inclined according to the undulation of the rail R.

{Accelerometer}
When the gantry 2 travels at a constant speed along the guide rail R, the accelerometer 3 detects a component of gravitational acceleration generated in the plane direction of the gantry 2 due to the tilt of the gantry 2 generated according to the undulation of the rail R. The plane direction of the gantry 2 is the direction along the horizontal direction when the gantry 2 is mounted on the guide rail R along the vertical direction without undulation, and in this example, the direction along the top and bottom surfaces of the gantry 2 That is.

  The accelerometer 3 has a detection method such as a piezoelectric method or a servo method, but an accelerometer capable of detecting low-frequency vibrations, particularly an accelerometer capable of detecting a DC component (static acceleration) can be preferably used. An accelerometer capable of detecting static acceleration can measure the swell (displacement amount) of the guide rail R with high accuracy. In this example, a servo accelerometer LS-10C manufactured by Lion Co., Ltd. is used as the accelerometer 3.

  The number of accelerometers 3 is preferably plural. The waviness of the guide rail R is generated when the guide rail R is distorted in at least one of the front-rear direction and the left-right direction. Therefore, if the acceleration in two directions orthogonal to each other in the plane direction of the gantry 2 can be measured by the plurality of accelerometers 3, the undulation of the guide rail R can be grasped three-dimensionally. In this example, a pair of accelerometers 3 is used so that acceleration in the two directions of front and rear and left and right in the plane direction of the gantry 2 can be measured. When the gantry 2 is tilted, the accelerometer 3 detects a gravitational acceleration component generated in each of the front-rear direction and the left-right direction.

{Recorder}
The recorder 4 records the measurement result of the accelerometer 3. The recorder 4 may be mounted on the gantry 2 or may be provided at a location away from the gantry 2 so that the measurement result of the accelerometer 3 can be received wirelessly. In the former case, there is no need for transmitting means for transmitting the measurement result of the accelerometer 3 to the recorder 4 on the gantry 2 side, and no receiving means for receiving a signal from the transmitting means is required on the recorder 4 side. is there. On the other hand, in the latter case, a recorder is not required on the gantry 2 side, and the gantry 2 side can be easily reduced in size and weight. In this example, a 4ch data recorder DA-20 manufactured by Rion Co., Ltd. is used as the recorder 4, and this recorder 4 is mounted on the gantry 2. This data recorder can use a commercially available battery as a power source, and uses a memory card (CF card) as a recording medium.

{Power supply}
A power source 5 is also mounted on the gantry 2. The power source 5 supplies power to the accelerometer 3 described above. In this example, the power supply 5 is a servo accelerometer power supply LF-20 manufactured by Lion Co., Ltd.

{Suspension material}
The suspension member 6 suspends and supports the base 2 and the set of mounting members on the base 2 from the constant speed traveling unit 1. Install an accelerometer in the constant-speed traveling section, or configure the constant-speed traveling section and the gantry together with a substantially inflexible connector, and install an accelerometer on the gantry to configure the traveling object It is also possible. However, in that case, the accelerometer can easily detect vibrations associated with the travel of the travel target. This tendency becomes more prominent when the power source 5 described above is provided and the weight on the gantry 2 side increases. As a result, there is a risk that noise in the measured acceleration waveform will increase. Therefore, if the constant-speed traveling unit 1 and the gantry 2 are independent members and the gantry 2 is suspended from the constant-speed traveling unit 1 via the suspension member 6, noise can be reduced and a predetermined acceleration component can be accurately detected. be able to.

  As the suspension member 6, a flexible member such as a wire can be preferably used. It is possible to suspend and support the vicinity of the connecting portion of the gantry with the guide rail R using a single wire, but the gantry 2 is suspended with a plurality of wires. It is preferable to lower. It is preferable that the upper ends of the wires are connected to the constant-speed traveling unit 1 in a concentrated manner, and the lower ends of the wires are connected in a distributed manner at three or more locations that divide the contour outer edge of the gantry 2 in plan view at substantially equal intervals. is there. In this example, a total of four wires are used, and the lower end of each wire is connected to the vicinity of the corner at the outer edge of the square outline in plan view of the gantry 2, that is, on both sides of the rear surface of the gantry 2 and the front side of each side surface. Yes. With such a wire arrangement, it is possible to effectively suppress vibration due to backlash with the guide rail R of the constant speed traveling unit 1 being transmitted as large vibration to the gantry 2 through the wire.

{Displacement calculation means}
The displacement amount calculating means 7 calculates the displacement amount of the guide rail R using the measurement result recorded in the recorder 4. This calculation procedure will be described with reference to FIG. When the gantry (accelerometer 3) is supported by a guide rail without undulations and the plane direction is along the horizontal direction (left and right direction in FIG. 3), as shown in FIG. g = 9.8m / s ² ) acts and no acceleration component of gravity occurs in the plane direction. On the other hand, when the gantry (accelerometer 3) is tilted according to the swell of the guide rail, the plane direction is deviated from the horizontal direction as shown in FIG. 3B, and an acceleration component of gravity is generated in the plane direction. This acceleration component a is expressed by the following equation 1 where θ is the deviation angle of the accelerometer 3 from the vertical direction (the deviation angle of the plane direction of the accelerometer with respect to the horizontal direction).
Acceleration component a = 9.8sinθ ... Equation 1

  On the other hand, the descent speed of the constant speed traveling part (mounting platform) is a constant speed by the safety device, the length of the guide rail R that is the measurement range is L (m), the time from the descent start to stop t ( Assuming s), the descending speed is expressed in L / t (m / s).

In addition, since the sampling time of acceleration data is 1/256 (s) in the case of the above recorder 4, the moving distance y (m) of the constant speed traveling unit 1 (mount 2) for each sampling time is Represented by 2.
Travel distance y = (L / t) x (1/256) ... Formula 2

Therefore, the displacement x (mm) of the guide rail at the moving distance y of the constant speed traveling unit 1 (base 2) is expressed by the following formula 3, as shown in FIG.
Displacement x = ysinθ = (L / t) × (1/256) × sinθ ... Equation 3

From the above, the displacement amount x is expressed as follows using the acceleration component a from Equation 1 and Equation 3.
Displacement x = (L / t) x (1/256) x (a / 9.8)

  That is, the amount of displacement of the guide rail can be measured using the traveling speed of the gantry and the component of the gravitational acceleration generated in the plane direction of the gantry. The above calculation can be easily performed using commercially available spreadsheet software or the like by taking acceleration data recorded in a recorder into a computer.

{Measurement procedure}
The measurement of the displacement amount of the guide rail R using the above apparatus is performed according to the following procedure.

  (1) Set the accelerometer 3, the recorder 4 and the power source 5 on the gantry 2 and connect them to the constant speed travel unit 1 with a wire so that the accelerometer 3 is positioned at the descent start position. And set the stand 2 on the guide rail R. The descent start position is a position corresponding to a mounting bracket that holds the upper end of a certain unit rail R, for example. At that time, the stopper of the constant speed traveling unit 1 (safety device) is allowed to act.

  (2) A stop bracket for stopping the displacement measuring device is fixed to the lower end of the guide rail R.

  (3) Turn on the power supply 5 for the accelerometer 3 and the power supply of the recorder 4.

  (4) Start recording of the recorder 4 and record acceleration data of the accelerometer 3.

  (5) Release the stopper of the constant speed traveling part 1 (safety device) and lower the displacement measuring device along the guide rail R.

  (6) When the displacement measuring device reaches a predetermined position at the lower end of the guide rail R and stops, the recording of the recorder 4 is stopped.

  (7) The gravitational acceleration component data recorded by the recorder 4 is taken into the computer.

  (8) Using a computer as the displacement amount calculation means 7, the displacement amount is obtained by using the constant speed traveling unit 1 and the acceleration component data of gravity.

{Function and effect}
The displacement measuring apparatus according to the present invention described above can achieve the following effects.

  (1) When the constant speed traveling unit 1 is traveled at a constant speed along the guide rail R, the gantry 2 is also traveled in synchronization with the constant speed traveling unit 1. Therefore, the gantry 2 is inclined according to the undulation of the guide rail R, and an acceleration component of gravity is generated in the plane direction of the gantry 2. If this acceleration component is measured by the accelerometer 3, and the measurement result is recorded in the recorder 4, the swell of the guide rail R, that is, the guide rail is obtained by using the measurement result and the traveling speed of the constant speed traveling unit 1. With respect to the straight line connecting the upper two points, the distribution of the displacement amount of the guide rail located between the two points can be obtained by calculation.

  (2) By using the constant-speed traveling unit 1 and the gantry 2 as separate members and suspending the gantry 2 from the constant-speed traveling unit 1 with the suspension material 6, vibration caused by the traveling of the constant-speed traveling unit 1 is directly applied to the gantry 2 It is possible to suppress the transmission and accurately determine the swell (displacement amount) of the guide rail R.

  (3) By detecting the acceleration component of gravity associated with the inclination of the two plane directions orthogonal to each other in the front-rear direction and the left-right direction of the gantry 2, the undulation in the front-rear direction and the left-right direction of the guide rail R can be measured in one measurement. Can be detected.

[Test Example 1]
Using the displacement measuring apparatus according to the first embodiment, the displacement of the fall prevention safety device guide rail R was measured. Here, as a measurement model, as shown in FIG. 4, with respect to the 4 m region of the guide rail R, a total of three locations, both ends and the center, are fixed to the angle member P1 via the mounting bracket F, and the central mounting bracket A guide rail R having a different amount of displacement was prepared by changing the distance between the tip of the angle member P1 and the angle member P1. The measuring direction of the displacement amount is the left-right direction (lateral direction) along the width direction of the traveling piece R1 (see FIG. 2A) of the angle member P1, and the width direction of the connecting piece R3 (see FIG. 2A). It was set as each of the front-back direction (longitudinal direction) along. For the measurement of the displacement amount, an actual measurement performed in advance using a scale and a measurement using a displacement amount measuring device were performed, and the actual measurement value was compared with the measured value. In the actual measurement in the lateral direction, the linear distance between the extended surface of one surface of the angle member and the surface of the running piece R1 that is parallel to the extended surface and close to the extended surface is measured. This is done by measuring the linear distance between the extended surface of the surface and the surface of the running piece R1 parallel to the extended surface or the surface of the support piece R2 (see FIG. 2 (A)) close to the extended surface. It was.

  An example of the measurement result is shown in FIG. As a result, all measured values approximated to the actually measured values, and it was found that highly reliable measurement is possible with the displacement measuring device of the present invention.

Furthermore, the relationship between a plurality of measurement values including the measurement result example of FIG. 5 and the actual measurement values was examined in each of the left / right (horizontal) direction and the front / rear (vertical) direction. The result is shown in the graph of FIG. As is apparent from this graph, in either direction, the determination coefficient R ² of the measured values and the measured value is 0.9 or more, it was confirmed that there is a strong correlation.

[Test Example 2]
Next, the displacement amount of the fall prevention safety device guide rail R actually attached to the steel tower was measured using the displacement amount measuring apparatus according to the first embodiment. In Test Example 1, the displacement of the guide rail R at the 4m length was measured, but in this example, the displacement of a series of guide rails R fixed by mounting brackets along the main pillar of the steel tower was measured. (Continuous measurement) and measurement of the displacement amount (division measurement) in the range of every three mounting brackets on the guide rail R, and whether the displacement amount at the position corresponding to the latter of the former corresponds to the displacement amount of the latter I investigated whether or not.

  In continuous measurement, as shown in FIG. 7A, the displacement measuring device of the first embodiment is continuously lowered from the top to the bottom of the guide rail R, and the displacement over the entire length of the guide rail R is performed by one drop. Measure quantity. On the other hand, in the split measurement, as shown in FIG. 7 (B), the displacement measuring device of Embodiment 1 is lowered from the top of the guide rail R, and first, the range from the first to the third of the mounting bracket F is measured. The displacement amount is measured, and then the displacement amount is measured for the second to fourth mounting bracket F. Subsequently, the amount of displacement is measured in the range from the nth to the (n + 2) th of the mounting bracket F, and this measurement is repeated until the (n + 2) th mounting bracket F becomes the lowermost mounting bracket F. In addition, since the measurement object of this example is the guide rail R of the actual steel tower ST, the mounting intervals of the mounting brackets F are not uniform.

  As a result, the measurement results of a plurality of continuous measurements were almost the same, and it was found that measurement with reproducibility was possible by measurement using the apparatus of the present invention. An example of measurement results of continuous measurement is as shown in FIG. Moreover, when the measurement results of the continuous measurement in the range corresponding to each measurement location of the split measurement are compared with the measurement results of the split measurement, they are almost corresponding, and one measurement over the entire length of the guide rail R. It was found that reliable results were obtained. An example of the comparison result is shown in FIG. When the measurement data from the 4th to 6th of the mounting bracket extracted from the measurement data of the continuous measurement is compared with the measurement data of the split measurement at the same location, as shown in Fig. 9 (A) and (B) , You can see that they are almost identical. 9C and 9D show a comparison between the measurement data of the seventh to ninth mounting brackets extracted from the measurement data of the continuous measurement and the measurement data of the split measurement at the same location. As you can see, they are almost identical.

  The present invention is not limited to the above-described embodiment, and various modifications can be made as necessary within the scope of the gist of the present invention. For example, the apparatus of the present invention can be used to measure the amount of displacement of a long material installed in a substantially vertical direction even if it is other than a guide rail of a steel tower fall prevention safety device. Therefore, it can be said that the displacement amount can be measured with sufficiently high reliability by one continuous measurement.

  The apparatus for measuring the amount of displacement of the long material of the present invention can be suitably used for measuring the amount of displacement due to swells generated in a long material such as a rail for fall prevention safety devices laid on a steel tower.

1 Constant-speed traveling part 2 Mounting base 3 Accelerometer 4 Recorder 5 Power supply 6 Suspension
7 Displacement amount calculation means R guide rail R1 traveling piece R2 support piece R3 connecting piece
RH Mating hole ST Steel tower F Mounting bracket P Main pillar P1 Angle material

Claims (6)

A constant speed traveling section that travels at a constant speed along a long material extending in the vertical direction;
This together with the constant-speed running portion is moved along the elongated member, and and the Ru member der mutually independent and constant-speed running unit pedestal,
An accelerometer that measures the acceleration in the plane direction of the gantry, and measures an acceleration component of gravity that occurs in the plane direction of the gantry tilted according to the undulation of the long material, and
A recorder that records the measurement results of this accelerometer ,
An apparatus for measuring a displacement amount of a long material, comprising: a suspension material for suspending the mount from the constant speed traveling unit .
However, the plane direction of the gantry means a direction along the horizontal direction when the gantry is mounted on a long material along the vertical direction without waviness. The apparatus according to claim 1, wherein the accelerometer is a servo accelerometer. A pair of the accelerometers are provided,
Each accelerometer of claim 1 or 2, characterized in that mounted on the frame so as to measure the acceleration component caused by the inclination relative to the longitudinal direction and each of the planar direction of the horizontal direction of the frame Displacement measuring device for long materials. A power supply for the accelerometer;
The displacement measuring device for a long material according to any one of claims 1 to 3 , further comprising a recorder for measuring the measurement result of the accelerometer. The said constant speed traveling part is a fall prevention safety device which prevents a worker from falling suddenly by descending at a constant speed along the long material when the worker falls. The apparatus for measuring the amount of displacement of the long material according to any one of to 4 . The displacement measuring apparatus for a long material according to any one of claims 1 to 5 , wherein the long material is a guide rail of a fall prevention safety device attached to a steel tower.

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