JPH01242902A - Detector for shape measurement - Google Patents

Abstract

PURPOSE:To obtain the inexpensive, lightweight detector of simple constitution and to reduce the external diameter by detecting the deformation of a curvature detection cylinder corresponding to the shape of a body to be measured by strain gauges added to a strain induction part in the for of electric signals. CONSTITUTION:For example, an earth rod 25 as the body to be measured is implanted in the ground surface 27 and the peak part 25a is bent by a stone 28. A sensor part 18 is inserted into a sensor hole 26 from its top by holding a lead wire. This sensor part 18 consists of a sensor pipe 1 as the flexible and thin curvature detection cylinder for the external diameter, the strain induction part 2 inserted into the pipe 1 while twisted by at least >=90 deg., and the strain detection part consisting of strain gauges 10-13 which are stuck on the top and reverse surfaces of the orthogonal crossing surface part 4 and reference surface part 8 of the strain induction surface of the strain induction part 2 in pairs. Then the deformation of the pipe 1 corresponding to the shape of the earth rod 25 by the inserting of the sensor part 18 is detected by the gauges 10-13 in the form of electric signals, which are used to measure the shape of the earth rod 25 by specific computation.

Description

Detailed Description of the Invention (a) Technical Field The present invention relates to a shape measuring detector, and more specifically, a detector for detecting bending is inserted into a pipe-shaped object to be measured and detects the shape according to the shape of the object to be measured. The present invention relates to a shape measuring detector for measuring the shape of the object to be measured by detecting the deformation of the bending detection tube as an electric signal.

(b) Conventional technology Grounding work for electric power is regulated by the technical standards for electrical equipment established by Ministry of International Trade and Industry Ordinance No. 61 based on the provisions of the Electricity Business Law, and for example, depending on the scale of the electrical equipment, etc. (10Ω or less), Type 2 grounding work, Type 3 grounding work (100Ω or less), and special Type 3 grounding work (10Ω or less) are required. Also,
Even if the above technical standards are not followed, grounding is often desirable due to the characteristics of the equipment.

By the way, the number of grounding rods used in the distribution lines of nine electric power companies from Hokkaido to Kyushu is around 2 million a year.

Most of these are used in places where there are no underground objects, such as mountains or fields, but there are also a large number of grounding rods that are driven into urban areas where there are many underground objects such as gas, water, electricity, and telephones. amounting to . Conventionally, when grounding work is carried out in urban areas, the location of gas pipes, etc. is investigated in advance using a metal detector that uses radio wave reflection to detect underground metal, and then grounding is carried out at a location where there is no risk of contact with these pipes. Although the grounding rod was supposed to be driven in, there were cases where the grounding rod bent underground, causing unexpected accidents. In other words, when a grounding rod is driven into the ground almost perpendicularly from the ground, it bends midway due to obstacles such as stones, and from there it continues to advance in a diagonal direction. When the ground rod hits a third obstacle, the bending increases further, and the ground rod may move in an inclined direction. There have been cases where gas pipes and the like were located in this slanted direction and were destroyed, resulting in an accident. Such dangers (accidents)
In order to eradicate this problem, it would be desirable to have a device that detects the proximity of a ground rod to a metal object buried underground and issues an alarm, such as a device that detects and warns of abnormal proximity between a crane and a power transmission line. , unlike in the air, the physical
Due to reasons such as the complexity of electrochemical properties and the fact that soil moisture content and electrical resistance are not uniform over time and space,
Developing an abnormal approach detection device underground is extremely difficult.
It has not been proposed yet.

Also, for detecting the above-mentioned bends and inclinations of the ground rod.

Precisely measure the slope of structures and the ground. It is conceivable to use a so-called inclinometer or inclination sensor. An example of the above inclinometer will be described below.

Changes in the condition of the ground, etc. can be detected by, for example, burying a guide pipe vertically in the ground, inserting an inclinometer into the guide pipe in advance or after an appropriate period of time, and checking the position of the guide pipe at each predetermined depth position. This can be determined by measuring the angle of inclination.

FIG. 11 is a diagram that was previously filed by the applicant in Japanese Patent Application No. 57-143373.
1 is a schematic diagram for explaining the principle of a conventional inclinometer proposed as No. 59-34111.

In the figure, a and b are fixed parts that are inclined to be similar to the guide pipe (not shown) buried in the ground as the object to be measured, and C is a fixed part whose upper end is connected via a hinge d. It is a highly rigid beam section which is pivotably attached to the fixed section a and has a weight e having a weight W at the lower end. f is a strain plate whose one end is fixed to the fixed part and the other end is connected to the weight e via the axial displacement absorbing spring S, and the strain plate f has a strain surface near the fixed part. A strain gauge g is attached by adhesive or other means.

In the inclinometer shown in Fig. 11 configured in this way, when the guide pipe is tilted due to a landslide or ground movement, the fixed parts a and b tilt together with the guide pipe, but the beam part C is tilted by the weight e. It is always maintained in the vertical direction by the load W. Therefore, the strain plate f is in the central axis direction i of the guide pipe.
The strain gauge g deflects in accordance with the inclination angle θ between the vertical direction and the inclination angle θ, and the strain output in accordance with the inclination angle θ is derived from the strain gauge g. Changes in the state of the ground are then measured from the position of the inclinometer in the guide pipe and the inclination angle θ at that position.

12(a) and (b) show an insertion type strain gauge type inclinometer 51 (hereinafter referred to as inclinometer 51) based on the principle of FIG. 11.
1) is inserted into a guide pipe 53 buried in the ground 52. FIG. As shown in the figure, this guide pipe 53 has four guide grooves 53a along the longitudinal direction of its inner peripheral wall.
~53d is formed. On the other hand, two levers 54a, 54a are pivoted at the center of the inclinometer 51 at two locations near the end thereof, and each of the two levers is provided with a left-rotating behavior by a spring (not shown). 54a, 54a
Pulleys 54b are rotatably attached to both ends of the pulley 54b. The inclinometer 51 is inserted into the guide pipe 53 with the pulley 54b fitted into the guide grooves 53b and 53d (or 53a and 53c).

In this way, the inclinometer 51 inserted into the guide pipe 53
is inclined together with the guide pipe 53.

The inclination angle of the guide pipe 53 at the location where the inclinometer 51 is inserted is measured by appropriately processing an electric signal corresponding to the amount of deflection of the strain plate f derived from the strain gauge g.

On the other hand, the ground rod is about 1oan in diameter and 1m in length,
If this ground rod is processed into a pipe shape and used as the guide pipe 53, it is possible in principle to insert the inclinometer 51 shown in FIG. 12 into the pipe-shaped ground rod.

However, in general, the outer diameter of the inclinometer 51 is about 10 mm.
To apply to a ground rod with a diameter of about 10+ nm, use an inclinometer 5
1 must be extremely miniaturized (thinner in diameter). However, as shown in FIG. 12, the inclinometer 51 has a complicated structure and is difficult to miniaturize.Even if it could be miniaturized, the complexity of the structure would make it extremely expensive and unsuitable. There is a problem with being realistic.

(c) Purpose The present invention has been made in view of the above-mentioned circumstances, and its purpose is to have a simple structure, be inexpensive, lightweight, and also be able to have an extremely small outer diameter, and to A morphometric detector that can be inserted into the inside of a measured object, thereby simultaneously detecting, for example, the bending angle and bending direction of the measured object, and thereby measuring the shape of the measured object. It is about providing.

(d) Structure In order to achieve the above-mentioned object, the present invention consists of a bending detection tube made of a flexible, small-diameter cylindrical member, and a band-like thin plate member having elasticity. A strain-generating portion which is loosely inserted into the bending detection cylinder in a twisted state and fixed to the bending detection cylinder at both ends in the longitudinal direction; A strain gauge is attached to each strain-generating surface and the resistance value changes according to the strain generated on each strain-generating surface. The structure is such that the shape of the object to be measured can be measured by detecting an electrical signal using a plurality of strain gauges attached to a strain part and performing predetermined arithmetic processing based on the electrical signal.

An embodiment of the present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1 is a partially cutaway elevational view showing the configuration of a sensor section of a morphometric detector according to an embodiment of the present invention, and FIG.
It is a top view of the same Example. In Figures 1 to 2, 1
is a sensor pipe as a bending detection cylinder made of a flexible pipe such as Teflon and having a small outer diameter φ1 (in this example, φ1 = 4 m1 to 4). This is a strain-generating portion that is inserted into the sensor pipe 1 in a twisted state by more than one rotation (in this example, several rotations).

3 to 6 are reference planes among the strain generating surfaces of this strain generating part 2 (orthogonal surfaces having surfaces perpendicular to the surface of the portion fixed to the upper end of the sensor pipe 1, and 7 to 9 are surfaces along the reference plane, respectively) The reference plane parts 10 and 11 each have a strain gauge and a strain gauge 12 attached in pairs to the front and back strain-generating surfaces of the orthogonal plane part 4, respectively.
and 13 are strain gauges attached in pairs to the front and back strain-generating surfaces of the reference surface section 8, and these strain gauges 1
0 to 13 constitute a strain detection section.

Fixing pins 14 and 15 respectively fix both ends of the strain generating section 2 to the sensor pipe 1, and 16 and 17 respectively hold both ends of the strain generating section 2 so that they are positioned approximately at the center of the sensor pipe 1. It is a spacer.

It is assumed that the strain gauges 10 to 13 are coated with mold material for moisture proofing.

Furthermore, although both end faces in the width direction of the strain-generating portion 2 and the inner wall of the sensor pipe 1 are loosely fitted and in sliding contact, the friction is small and the strain-generating portion 2
It does not affect the movement (displacement) of. Further, the lead wires for leading the outputs of the strain gauges 10 to 13 to the outside are arranged in the space 1a of the sensor pipe 1 along the strain generating part 2, and are further led out through the spacer 16. shall be taken as a thing.

FIG. 3 is a side view showing the overall configuration of the morphometric detector. In the figure, 18 is the sensor section shown in FIG. 1, and 19 is an elongated rod-shaped member having an outer diameter smaller than or equal to at least the outer diameter φ1 of the sensor section 18, and having appropriate elasticity and rigidity. This is a lead part connected to the upper end of the part 18.

FIG. 4 is a block diagram of a morphometric device (hereinafter referred to as "this device") to which the morphometric detector according to the present invention is connected.

In the figure, GS and ON are strain gauges corresponding to the strain gauges 10 and 11 attached to the above-mentioned orthogonal surface section 4, respectively, and GE and GW are the strain gauges 13 and 11 attached to the above-mentioned reference plane section 8, respectively. Strain gauge corresponding to 12, R1 and R3 are adjustment resistors, R2,
R4 is a so-called dummy gauge, and these resistors R1 to R
4 and the strain gauges GS, ON, GE, and GW constitute two Wheatstone bridges.

Reference numeral 20 denotes a strain gauge whose positive electrodes are connected in parallel to the respective connection points of the strain gauge ON and the adjustment resistor R1 and the strain gauge GE and the adjustment resistor R3, which form the bridge side where the positive electrodes are adjacent to each other, and whose negative electrodes form the bridge side where the negative electrodes are adjacent to each other. GS and dummy gauge R2 and strain gauge GW and dummy gauge R4
This is a bridge power supply that is connected in parallel to each connection point of the two bridges and supplies power to the two bridges.

21 are strain gauges GS and G forming adjacent bridge sides.
Input terminals A1 and A2 are connected to the respective connection points of the dummy gauge R2 and the adjustment resistor R1, which form the bridge side N, and the strain gauge GE, which also forms the adjacent side.
and GW, dummy gauge R4 forming the adjacent side, and adjustment resistor R
3 is connected to the input terminals B1 and B2, respectively, and 22 is connected to the output terminal D1 of the computing unit 21, and a bending direction indicator (hereinafter simply referred to as " 22a is a rotatable pointer, 23 is a bending angle indicator which is also connected to the output terminal D2 of the computing unit 21 and displays the bending angle of the sensor section 18, and 24 is the bending angle indicator of the computing unit 21. This is a cumulative angle indicator that is connected to the output terminal D3 and displays the cumulative bending angle each time the sensor section 18 bends. Note that the arithmetic unit 21 has input terminals Al, A2 . The direction and angle of bending are calculated from the signals received by Bl and B2, and outputted to output terminals D1 and B2, and the angles are memorized and the angles due to the next input are sequentially added and outputted to output terminal D3. It is configured.

Further, as already mentioned, only the portion 4°8 indicated by the dotted line is located in the sensor section 18, and the rest are located on the device side.

FIG. 5 is a longitudinal sectional side view showing a grounding rod as an object to be measured to which the present invention is applied.

In the same figure, 25 is a hollow cylindrical earthing rod made of copper or the like with an outer diameter of 10 m5 and a length of about 1m, 25a is a sharp conical tip of this earthing rod, and 25b is an earthing rod 25. The impact part 26 is the sensor part 18 that is hit with a hammer or the like when driving the material into the ground. In other words, sensor pipe 1
The impact part 2 has an inner diameter φ2 that is slightly larger than the outer diameter φ1 of the
This is a sensor hole drilled from 5b to just before reaching the pointed head 25a.

FIG. 6 is an explanatory diagram of the measurement principle showing the relationship between the amount of deformation and the amount of strain in a thin plate.6 In the figure, H is the thickness of the thin plate T;
C1 is the center line before the thin plate T is deformed, C2 is the center line of the deformed (bent) part, θ is the central angle of the bent part, R is the radius of curvature of the bent part, 0 is the center of curvature of the bend, and L is the bent part The distance between the centers of This is the angle formed with the center line C1, that is, the bending angle of the thin plate T.

When the amount of strain is ε, the following equation is generally known.

2ε=H/R(1) θ=L/R(2) From equations (1) and (2), θ=2εL/H(3) Also, using the similarity relationship, α=θ/2 (4) Therefore, , °, α=εL/H (5) In equation (5), the thickness H of the strain-generating portion 2 and the center-to-center distance are known, so the bending angle α can be obtained by knowing the amount of strain ε. .

FIGS. 7 and 8 are cross-sectional views showing the measurement operation.

In the figure, 27 is the ground, and 28 is a stone as an underground obstacle. In addition, the same reference numerals are given to the same members as those described above, and redundant explanation will be omitted.

9 and 10 are diagrams for explaining the operation of detecting the direction of bending.
FIG. 10, which is a plan view further modeled by cutting out one twisted section, is a graph showing the output of each strain gauge.

Note that the above-mentioned members are given the same reference numerals as above.

In Fig. 9, FN is the force applied to the strain-generating part 2 from the north direction, and similarly, FS, FE, and FW are the forces applied to the south, east, and south directions, respectively.
The force received from the west direction (direction), FO, is the force received from any direction.

In FIG. 10, VN and VS are voltages generated between input terminals Al and A2 when receiving forces FN and FS, respectively, and VE and VW are voltages generated between input terminals B1 and B1 when receiving forces FE and FW. The voltage generated between them, V○, is the voltage at the output terminal D1 when receiving the force FO. Note that the origin is Ov.

The operation and operation of this embodiment configured as described above will be explained.

As shown in FIG.
6 Further, when the striking portion 25b is struck with a hammer or the like and the pointed head 25a is driven downward, there is a stone 28 at the end of this earth rod, and the pointed head 25a is driven into the stone 2.
Assume that the pointed head 25a is bent by a bending angle α with respect to the center line C1 as shown in FIG. 8 due to further driving. Therefore, the operator first clears the stored contents of the cumulative angle in the device to zero using a reset switch (not shown). Along with this, the cumulative angle indicator 24
The displayed content is cleared to zero and becomes 00.0°.

Next, align the mark (not shown) placed on the lead part 19 in the same direction as the strain gauge 11 (strain gauge GN) with the north direction, and then hold the lead part 19 and insert it into the sensor part 1.
8 from the top of the sensor hole 26. Then, stop at the upper part of the sensor hole 26, that is, the straight part along the center line C1, and perform the initial setting of the device, that is, the direction indicator 2.
Check whether the pointer 22a of No. 2 points to "N" and check whether the bending angle indicator 23 shows zero.

If it is not zero, zero adjustment is performed using adjustment resistors R1, R3, etc. Then, as shown in FIG. 8, the sensor section 18 is inserted up to the bent portion of the grounding rod 25. At this time, the first bending angle indicator 23 displays a numerical value corresponding to the bending angle α (for example, 45.
0"), and the cumulative angle indicator 24 also shows the value 45.0' corresponding to α since it is the first bend in this case.
Display. When the sensor part 18 is further inserted deeper, the sensor part 18 advances to a straight line along the tangent Q2 of the pointed head 25a, and the sensor part 18 returns to its original straight state (a state in which no external force is applied). Therefore, at this time, the bending angle indicator 24 is 0.
0.0''', and the cumulative angle indicator 24 shows the above 45.
Holds 0°.

Next, the inside of the sensor 18 when receiving such an external force will be described.

As shown in FIG. 9, the force FN is applied to the sensor pipe
When received through FN, the reference surface portion 8 acts rigidly on this side FN, so it does not change, and the orthogonal surface portion 4 bends as shown in FIG. In this case, strain gauge ON expands and strain gauge O3 contracts. In other words, the resistance of the strain gauge GN in FIG. 4 increases and the resistance of the strain gauge GS decreases, so that the input terminal A2 has a higher potential than A1. (This is considered a positive potential). The voltage between input terminals A2 and A1 at this time is VN in FIG. Conversely, when the force FS is applied, a negative voltage vS is generated. Next, when receiving force FE,
The orthogonal surface portion 4 acts rigidly and does not change, the reference surface portion 8 bends, the strain gauge GE stretches (resistance increases), and the strain gauge GW contracts (resistance decreases), so the input terminal B2 becomes 81.
The potential becomes higher (positive potential), and B2 at this time
The voltage between -B1 is VE. The concept of force FE is also the same, so the explanation will be omitted.

That is, as shown in equation (5), the amount of strain ε is proportional to the bending angle α, so the voltages VN and VS are equal to each other.

The bending angle α can be obtained by VE and VW.

Now, if the direction of bending in FIG. 8 is parallel to the plane of the paper, this corresponds to the force FE in FIG. 9, and therefore a voltage VE is generated. In this example, since the direction of bending is opposite to the generated voltage, the calculator 21 uses the pointer 2 of the direction indicator 22 to
An output signal that directs 2a to rWJ is sent from output terminal D1.

Therefore, the operator should now move the earth rod 25 toward due west by 45
◦Know that you can bend it and only bend it once.

Next, as a force FO in an arbitrary direction, a force F from approximately the southeast direction
Let us describe the case where O is received. in this case.

Both the orthogonal surface portion 4 and the reference surface portion 8 receive component forces of the force FO, and expand and contract, respectively. Therefore, as shown in FIG. 10, a voltage VSI in the S direction and a voltage VEI in the S direction and a voltage VEI in the VE force direction corresponding to each component force are generated, and these are applied to the pointer in the approximately northwest direction, which is the opposite direction of the combined direction vO. 22a is in the direction (shown in the fourth diagram), and the voltage magnitude vo (arrow v in the figure)
The length of O) indicates the bending angle. In other words, in accordance with FIG. 8, since the bending angle α is 45°, the length of the arrow vO is the same length (voltage) as when the force FE is applied from due west. Therefore, even if force F○ is applied from any direction, the angle and direction of bending can be known, and the earth
You can know the form of

As described above, according to this embodiment, the strain-generating part 2 made of an elastic strip-shaped thin plate twisted several times is fitted into the flexible small-diameter sensor pipe 1 and fixed at both ends, and the orthogonal Since the sensor section 18 is constructed by attaching a pair of strain gauges 10 to 13 to the front and back strain-generating surfaces of the surface section 4 and the reference surface section 8 substantially perpendicular thereto, the sensor section 18 is small and lightweight, and can be replaced with a conventional large inclinometer. There is an advantage that the sensor section 18 can be inserted into a small diameter sensor hole 26 that cannot be used. Therefore, there is an advantage that it can be used for the earthing stud 25, etc., where a thick sensor hole 26 cannot be drilled.

Further, upon receiving the outputs from the strain gauges 10 to 13 attached to the orthogonal surface section 4 and the reference surface section 8, the computing unit 21 calculates the angle and direction of the bend, and these are displayed on the direction indicator 22,
displaying the bending angle on the bending angle display 23 and storing the bending angle;
Since the cumulative angle is calculated and displayed on the cumulative angle display 24, it is possible to easily know the shape of the grounding beam bent in any direction, thereby preventing accidents such as accidentally destroying gas pipes, etc. This has the great advantage of being preventable.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

For example, the strain-generating portion 2 is not limited to being fixed only at both ends thereof, but if the strain-generating portion 2 is long and long, it is desirable to fix it to the sensor pipe 1 at other portions as well. In this case, there is an advantage that angular deviation can be prevented.

Furthermore, the degree of twisting of the strain-generating portion 2, that is, the pitch, is the first
Provided that a twist of at least 90° or more is ensured, but not limited to that shown in the figures.

There may be an increase or decrease. In addition, if the pitch is configured to be small,
There is an advantage that the accuracy (resolution) of morphometric measurement of a small area can be improved.

Furthermore, the strain gauges are not limited to being attached to one orthogonal surface portion 4 and one reference surface portion 8, but are attached to all orthogonal surface portions 3 to 8.
6 and all the reference plane parts 7 to 9, respectively. In this case, it goes without saying that the detection sensitivity of the hit will be improved. On the other hand, if it is acceptable to lower the detection sensitivity, the strain detection section may be configured with two sheets in total, one on one side of one orthogonal surface section 4 and one on one side of one reference surface section 8. good.

Further, the lead portion 19 is not limited to a rod-shaped member, and may be formed of something such as a piano wire, as long as there is a means (for example, a guide groove) that can maintain the directionality when the sensor 18 is inserted. .

Further, the lead portion 19 may be provided with a scale for measuring the depth when the sensor portion 18 is inserted into the earthing rod 25. In this case, morphometry becomes more reliable.

In addition, in the embodiment, the direction indicator 22 is analog, the bending angle indicator 23 and the cumulative angle indicator 2.
4 is a digital system, but it is not limited to this, and the opposite may be used, and all displays may be analog or
Alternatively, all indicators may be digital. Therefore, the direction indicator 22 may digitally display the counterclockwise angle with north (N) as 0°.

Furthermore, one display may display the measured form in three dimensions using a CRT display, without considering each individual item as described above.

In addition, although FIG. 8 shows the case where measurement is performed after the ground rod 25 is bent, if the earth rod is about 4 m long and the sensor part 18 is about 50 cm long, Regardless of whether there is a song or not, the sensor unit 18 may be inserted and measured every 50 times the earth rod is driven in, and the shape may be checked each time the earth rod is driven in.

In addition, it is possible to insert the sensor part 18 to the deepest point in the sensor hole 26 in advance, and to drive the ground stud 25 in this state.
In other words, it is possible to prepare a jig so that the lead part 19 does not get in the way, and to drive the grounding stud 25 through this jig while monitoring each display 22 to 23. In this case, the can be measured, which has the advantage of being able to avoid accidents that could damage underground objects such as gas pipes, and improving measurement efficiency.

Further, the application of the present invention is not limited to the earth rod 25,
If the object to be measured can only have a small diameter sensor hole 26,
Can be applied to anything.

(e) Effects As detailed above, according to the present invention, the structure is extremely simple, can be manufactured at low cost, and can be made lightweight and extremely thin in outer diameter. of the object to be measured by inserting it into an extremely thin hole.

For example, it is possible to provide a shape measuring detector that can simultaneously detect the angle of bending, the direction of bending, etc., and thereby measure the shape of the object to be measured.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway elevational view showing the configuration of a sensor section of a morphometric detector according to an embodiment of the present invention, and FIG.
A plan view of the embodiment, FIG. 3 is a side view showing a schematic configuration of the morphometric detector, and FIG. 4 is a block diagram of the morphometric device (this device) to which the morphometric detector is connected. figure,
Fig. 5 is a vertical cross-sectional side view showing a ground rod as a measured object to which the present invention is applied, and Fig. 6 is a diagram for explaining the relationship between the amount of deformation and the amount of strain of a thin plate. , FIGS. 7 and 8 are cross-sectional views showing the driving state of the earth rod as the object to be measured, and FIGS. 9 and 10 are views for explaining the operation of detecting the direction of bending. Of these, Fig. 9 is a plan view further modeled by cutting out a section of the strain generating section 2 twisted by 90°, Fig. 10 is a graph showing the output of each strain gauge, and Fig. 11 and Figure 12 (a
) and (b) both show conventional examples, and among them,
Figure 11 is a schematic diagram explaining the principle of an inclinometer, and Figures 12 (a) and (b) are inside a guide pipe in which an insertion type strain gauge type inclinometer based on the principle of Figure 11 is buried in the ground. FIG. 4 is a vertical cross-sectional view and a cross-sectional view showing the state when the device is inserted into the device. DESCRIPTION OF SYMBOLS 1...Sensor pipe, 1a...Space part, 2...Strain-generating part, 3-6...
... Orthogonal plane part, 7-9...'... Reference plane part, 10-13... Strain gauge, 14.15...
...Fixing pin, 16.17...Spacer. 18...Sensor part, 19...
Lead part. GS, GN, GE, GW...Strain gauge, R
2, R4...Dummy gauge. R1, R3...Adjustment resistor, 20...Bridge power supply, 21...Arithmetic unit, 22...Bending direction indicator, 23... - Bending angle indicator, 24... Cumulative angle indicator. 25... Earth rod.

Claims (1)

[Claims] (1) A bend detection tube made of a flexible, small diameter cylindrical member and an elastic strip-shaped thin plate member, which is inserted into the bend detection tube with the strip-shaped thin plate member twisted by at least 90° or more. and a strain-generating portion whose longitudinal ends are fixed to the bending detection cylinder, and a strain-generating portion that is attached to strain-generating surfaces that are twisted at 90 degrees to each other, and the strain generated on each strain-generating surface is and a strain gauge whose resistance value changes according to the shape of the object to be measured, and detects the deformation of the bending detection tube that deforms according to the shape of the object to be measured as an electric signal by the plurality of strain gauges attached to the strain generating part. A detector for measuring morphology, characterized in that it is configured to be able to measure the morphology of the object to be measured by performing predetermined arithmetic processing based on the electrical signal.