Straight line accuracy measuring device

Abstract

To provide a linear accuracy measurement device that has a simplified structure, can easily discriminate the linear accuracy of a tubular body, and has high versatility.SOLUTION: A linear accuracy measurement device 1 comprises: measurement means 21, 30, 31 that measure an eccentric state at respective positions in an axial direction of a tubular body buried in the ground; a storage unit 33 being storage means that stores the eccentric state at the respective positions in the axial direction of the tubular body measured by the measurement means 21, 30, 31; and a display part 32 being display means that displays an entire bending state in the axial direction of the tubular body on the basis of the eccentric state at the respective positions in the axial direction stored in the storage unit 33.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a straightness accuracy measuring device for measuring the straightness accuracy of, for example, a drilled cylindrical casing. [Background technology]

[0002] Traditionally, in construction work, when drilling holes into the ground vertically, horizontally, or in any other direction using a boring machine, the holes may not be drilled according to the planned alignment due to installation accuracy issues or spiral deviation in the rotation direction of the boring machine. Since deviations from the planned alignment can cause quality issues, measuring linear accuracy at least during and after drilling is an important management item. Conventional measurement methods include the use of continuous inclinometers, but this method is not widely used due to the complicated and time-consuming measurement procedures, such as inserting the inclinometers, as well as the high cost involved.

[0003] Furthermore, a conventional linearity accuracy measuring device of this type is disclosed, for example, in Patent Document 1. This device comprises a laser plumb gauge attached to the top of the steel pipe, a guide member formed to be approximately the same size as the outer shape of the steel pipe, a target attached to the guide member and receiving the laser light irradiated from the laser plumb gauge, an imaging device for photographing the position at which the laser light irradiated on the target reaches, and a display device for displaying the image photographed by the imaging device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5332943 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the linearity accuracy measuring device described in Patent Document 1 uses an imaging device to capture an image of a light receiving plate installed on a diaphragm, and displays the image on the display device to read the direction and amount of deviation of the spot position of the laser light from the point marker. This results in a complex structure, making it difficult to identify the amount of deviation, and it cannot be applied to steel pipes arranged horizontally, resulting in a lack of versatility.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a highly versatile linear accuracy measuring device that has a simplified structure and can easily determine the linear accuracy of a tubular body. [Means for solving the problem]

[0007] In order to solve the above problem, the invention described in claim 1 of the present invention is characterized by comprising a measuring means for measuring the eccentricity state at each axial position of a tubular body buried in the ground, a memory means for storing the eccentricity state at each axial position of the tubular body measured by the measuring means, and a display means for displaying the bending state of the entire axial direction of the tubular body based on the eccentricity state at each axial position stored in the memory means.

[0008] Furthermore, the invention described in claim 2 of the present invention is characterized in that, in addition to the configuration described in claim 1, the measuring means has an imaging means for capturing images of the eccentricity state at each position in the axial direction of the tubular body, and is configured to display the images of the eccentricity state at each position of the tubular body captured by the imaging means on the display means.

[0009] Furthermore, the invention described in claim 3 of the present invention, in addition to the configuration described in claim 1, is characterized in that it has a movable member that is movable along the axis of the tubular body on the inner side of the tubular body, and whose rear end surface in the moving direction is an identification surface, and the measuring means is equipped with an imaging means that captures an image of the identification surface when the movable member moves along the axial direction of the tubular body, and a discrimination means that discriminates the axial eccentricity state of the tubular body based on at least one of the loss condition of the captured image and the deviation of the imaging center position at any distance that the movable member has moved from the open end of the tubular body, relative to an origin position image captured by the imaging means at a position where the tubular body is not eccentric. [Effects of the Invention]

[0010] According to the invention described in claim 1 of the present invention, the eccentricity state at each axial position of a tubular body buried in the ground is measured by a measuring means, the eccentricity state at each axial position of the tubular body measured by this measuring means is stored in a memory means, and the bending state of the entire axial direction of the tubular body is displayed on a display means based on the eccentricity state at each axial position stored in this memory means, thereby simplifying the structure, making it easy to determine the linear accuracy of the tubular body, and increasing versatility.

[0011] Furthermore, according to the invention described in claim 2 of the present invention, in addition to the effects of the invention described in claim 1, the measuring means has an imaging means for capturing images of the eccentricity state at each position in the axial direction of the tubular body, and by displaying the images of the eccentricity state at each position of the tubular body captured by this imaging means on the display means, it is possible to easily determine the eccentricity state at each position in the axial direction of the tubular body that is buried underground and cannot be directly seen with the naked eye.

[0012] Furthermore, according to the invention described in claim 3 of the present invention, in addition to the effect described in claim 1, the discrimination means is configured to discriminate the axial eccentricity state of the tubular body based on at least one of the defect state of the captured image at any distance to which the movable member has moved from the open end of the tubular body and the deviation of the imaging center position, relative to the origin position image captured by the imaging means at a position where the tubular body is not eccentric.This simplifies the structure, makes it easy to determine the linear accuracy of the tubular body, and increases versatility. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic perspective view showing a linearity accuracy measuring device according to a first embodiment of the present invention. [Figure 2] 2 is a plan view showing an example of an arrangement pattern of LED lights provided on a sighting plate of a moving member of the linearity accuracy measuring device of FIG. 1. FIG. [Figure 3] 10A and 10B are explanatory diagrams showing examples of discrimination between a case where the imaging center position O is not in the shadow on the collimation plate of the moving member in FIG. 2 and a case where the imaging center position O is in the shadow. [Figure 4] 1 is a block diagram showing a control system of a linearity accuracy measuring device according to a first embodiment of the present invention. FIG. [Figure 5] 2 is a schematic perspective view showing a measurement procedure using the linearity accuracy measuring device of FIG. 1. FIG. [Figure 6] 2 is a front view showing an eccentric state of a casing pipe to which the linearity accuracy measuring device of FIG. 1 is applied. [Figure 7] 2 is an explanatory diagram showing the eccentricity state of the casing pipe at depths (1) to (5) and images of those depths using the linearity accuracy measuring device of FIG. 1. FIG. [Figure 8] 1. FIG. 4 is an explanatory diagram showing the eccentricity of the casing pipe from depth (6) to depth (10) and images of those depths, using the linearity accuracy measuring device of FIG. [Figure 9] 1. FIG. 4 is an explanatory diagram showing the eccentricity state of the casing pipe from depth (11) to depth (15) and images of those depths, using the linearity accuracy measuring device of FIG. [Figure 10]FIG. 10 is a schematic perspective view showing a linearity accuracy measuring device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

[0015] [First embodiment] Fig. 1 is a schematic perspective view showing a linearity accuracy measuring device according to a first embodiment of the present invention. Fig. 2 is a plan view showing an example of an arrangement pattern of LED lights provided on the sighting plate of the movable member of the linearity accuracy measuring device of Fig. 1. Figs. 3(A) and 3(B) are explanatory diagrams showing examples of discrimination between a case where the imaging center position O is not in shadow on the sighting plate of the movable member of Fig. 2 and a case where the imaging center position O is in shadow. Fig. 4 is a block diagram showing a control system of the linearity accuracy measuring device according to the first embodiment of the present invention.

[0016] In this embodiment, an example of measuring the linearity accuracy when drilling holes in a casing using a high-pressure jet mixing method will be described. The present invention is not limited to measuring the linearity accuracy when drilling holes in a casing using a high-pressure jet mixing method, but can be applied to any tubular body buried in any direction, including vertical, oblique, or horizontal, as long as the curvature or inclination of the tubular body relative to its axial direction is measured.

[0017] As shown in Figure 1, the linear accuracy measuring device 1 includes a movable member 10 that is movable along the axis C of the casing pipe 3 on the inner periphery of a cylindrical casing pipe 3 that is a tubular body buried vertically in the ground 2, and a measuring device 20 that has a camera 21 as an imaging means for capturing an image of the rear end face of the movable member 10 when the movable member 10 moves along the axial direction of the casing pipe 3.

[0018] In this embodiment, the casing pipe 3 has a diameter of, for example, 150 mm. In the following embodiment, an example will be described in which a still image of the rear end face of the moving member 10 is captured by the camera 21, but a video camera may also be used to capture a moving image.

[0019] The moving member 10 is formed in a cylindrical shape having a predetermined length (for example, a thickness of about 10 cm), and its outer diameter is formed to be slightly smaller than the inner diameter of the casing pipe 3 so that it can move along the inner diameter of the casing pipe 3. Note that if rolling members such as rollers or bearings are arranged at regular intervals around the outer circumferential surface of the moving member 10, it will be possible for the moving member 10 to move smoothly inside the casing pipe 3.

[0020] The moving member 10 is provided with a sighting plate 11, the rear end surface of which in the moving direction (travel direction) serves as an identification surface. This sighting plate 11 is provided with a number of LED lights, which are arranged concentrically at regular intervals from a center position O of the sighting plate 11 so as to emit light as a number of concentric circles 11a, as shown in FIG. 2, and are arranged radially from the center position O so as to emit light as a number of rays 11b. The pattern of the concentric circles 11a and rays 11b formed by the number of LED lights has a predetermined illuminance, making it distinguishable from the open end (pipe opening) 3a of the casing pipe 3. The pattern on the sighting plate 11 may be drawn with a reflective material, and light may be irradiated from the open end (pipe opening) 3a to enable identification.

[0021] Measuring device 20 is formed in a cylindrical shape with a bottom, and its outer diameter is set to be approximately the same as the outer diameter of open end 3a of casing pipe 3. Measuring device 20 has a winding / feeding member 23 installed in internal space 22. A hanging string 24 is wound around this winding / feeding member 23, and is configured to be able to pay out a predetermined length and take up a predetermined length. Movable member 10 is suspended from the tip of this hanging string 24. Therefore, in this embodiment, since casing pipe 3 is buried vertically in the ground 2, movable member 10 can be moved to any measurement position (measurement depth) within casing pipe 3 by paying out hanging string 24 from winding / feeding member 23.

[0022] The winding / feeding member 23 is provided with a length measuring mechanism 30 shown in Fig. 4, which measures the payout length of the hanging cord 24, thereby measuring the measurement position (measurement depth) of the movable member 10. This measurement data of the measured depth is output to a control unit 31, which serves as a discrimination means, and this measurement data is output to a display unit 32 via the control unit 31, and is also sequentially stored in a memory unit 33. This causes the payout length of the hanging cord 24 to be displayed digitally. As a result, an operator can visually determine the measurement position (measurement depth) of the movable member 10 in the axial direction within the casing pipe 3.

[0023] The control unit 31 comprises a CPU (Central Processing Unit), and the storage unit 33 comprises a RAM (Random Access Memory) and a ROM (Read Only Memory). The ROM stores data and programs whose contents need to be retained even when the power is turned off. The RAM temporarily stores data. The CPU realizes various functions by executing programs installed in the ROM. In addition to the ROM, the storage unit 33 includes computer-readable electronic media such as a DVD-ROM (Digital Versatile Disk Read Only Memory), a CD-ROM (Compact Disc Read Only Memory), and a hard disk. The data may be stored in a separately provided database instead of in the ROM.

[0024] Furthermore, the measuring device 20 has the camera 21 disposed at its center position, and the camera 21 is oriented to capture images in the axial direction inside the casing pipe 3. After temporarily setting the measuring device 20 at the open end 3a of the casing pipe 3, it is installed and fixed in place in a direction perpendicular to the planned drilling direction, and the plane coordinates are measured using a transit (surveying equipment that combines a spirit level and a telescope to measure horizontal and vertical angles) or the like.

[0025] The camera 21 used in this embodiment is basically equipped with an autofocus function that automatically adjusts the focus according to the distance from the sighting plate 11, but the operator may also manually adjust the focus and zoom. Also, the camera 21 is configured such that a cross-shaped, orthogonal line is marked on the surface of the lens 25, making it possible to determine the coordinates of the planar directions (horizontal and vertical directions) of the image captured by the camera 21.

[0026] The measurement position (measurement depth) of the movable member 10 measured by the length measuring mechanism 30 and the image data captured by the camera 21 at that position are stored in the memory unit 33 via the control unit 31 each time. Specifically, the depth data of the collimation plate 11 measured by the length measuring mechanism 30, for example, image data showing the amount of deviation and loss of the collimation plate 11 at a depth of 1 m, and image data showing the amount of deviation and loss of the collimation plate 11 at the next depth, for example, 2 m, are sequentially stored in the memory unit 33 via the control unit 31, and the depth data of the collimation plate 11 and the image data showing the loss status of the captured image are output to the control unit 31, whereby an image up to the planned depth in the axial direction of the casing pipe 3 can be displayed on the display unit 32. As shown in Figure 3(A), if the eccentricity is small enough that the imaging center position O does not overlap the casing pipe 3, it is also possible to identify the eccentricity at each depth by overlapping the imaging center position O. This allows the worker to easily determine the curved state and inclined state with respect to the axial direction of the casing pipe 3, which is buried in the ground 2 and the outside of which cannot be directly seen.

[0027] Next, an example will be described in which the linearity accuracy of a casing pipe 3 is measured using the linearity accuracy measuring device of this embodiment in accordance with the procedure shown in Fig. 5. In this embodiment, an example will be described in which the linearity accuracy of a casing pipe 3 is measured when drilling a hole in the casing using a high-pressure jet mixing method. Fig. 5 is a schematic perspective view showing the measurement procedure using the linearity accuracy measuring device of Fig. 1.

[0028] As shown in Figures 5(1) and 5(2), an inner rod 4 for drilling is installed inside the casing pipe 3, and the casing pipe 3 and inner rod 4 are used to drill a hole from the ground to the planned depth. Next, once the hole has been drilled to the planned depth, the inner rod 4 is detached and pulled out from the casing pipe 3 as shown in Figure 5(3), and then the linearity accuracy is measured according to the following procedure. In this case, the linearity accuracy of the casing pipe 3 may be measured during the hole drilling process.

[0029] To measure this linearity accuracy, first, as shown in Figures 5(4) and (5), a sighting plate 11, whose diameter is slightly smaller than the inner diameter of the casing pipe 3, is set inside the casing pipe 3 together with a moving member 10, and a hanging string 24 is connected to the sighting plate 11 and it is hung from the open end 3a of the casing pipe 3 to an arbitrary measurement position (measurement depth).

[0030] At this time, the sighting plate 11 is provided on the rear end surface of the moving member 10, which has a shape (in this embodiment, a cylindrical shape having a predetermined length) that is positioned in a vertical direction relative to the normal (axial) direction of the casing pipe 3, so that the plane of the sighting plate 11 always faces the plane position of the open end 3a of the casing pipe 3. Also, on the flat surface of the sighting plate 11, self-emitting LED lights are arranged in a geometric pattern as described above, and the pattern is configured to be discernible from the open end 3a of the casing pipe 3. Note that the sighting plate 11 can be replaced with a light-emitting body other than an LED light or a combination of a reflective material and a light source, as long as it has an illuminance that can be discerned from the open end 3a.

[0031] Next, as shown in Figure 5 (4), the measuring device 20 is set at the open end 3a of the casing pipe 3. The measuring device 20 is formed in a cylindrical shape with a bottom and an outer diameter that is the same as the inner diameter of the casing pipe 3, and the camera 21 is set so that the lens 25 is located at the axial center position of the measuring device 20. As a result, the shooting direction of the camera 21 is the axial direction of the casing pipe 3.

[0032] At this time, after temporarily setting the measuring device 20 at the opening end 3a of the casing pipe 3, the measuring device 20 is installed and fixed perpendicular to the planned drilling direction (horizontal if the planned drilling direction is vertical) as described above, and the planar coordinates are also measured using a transit or the like.

[0033] Next, when the sighting plate 11 reaches a desired depth within the casing pipe 3, the pattern of the concentric circles 11a and radial lines 11b of the sighting plate 11 at that desired position is photographed by the camera 21 attached to the measuring device 20. The photographing interval for the measured depth within the casing pipe 3 is, for example, every 1 m, and this is repeated until the planned depth is reached.

[0034] At this time, if the casing pipe 3 is drilled and installed in a straight line (according to the planned line), the pattern image captured by the camera 21 will have no gaps (missing parts) and will be captured as a perfect circle that is filled to the end, and there will be no deviation in the imaging center position O. On the other hand, if the casing pipe 3 has a bent part (including a linear eccentricity), the pattern image captured by the camera 21 will have missing parts and the imaging center position O will be shifted.

[0035] In this way, the control unit 31 receives data on the waxing and waning of the geometric pattern image and the displacement of the imaging center position O, as well as data on the measurement depth, and can determine the amount of eccentricity at any position on the casing pipe 3 based on this data. That is, the control unit 31 can determine the amount of eccentricity at any depth on the casing pipe 3 relative to a line with the measuring device 20 as the base axis, that is, the direction and extent of deviation. Note that, as shown in FIG. 3(B), even when the imaging center position O overlaps the casing pipe 3, it is also possible to identify the amount of eccentricity at a location other than the imaging center position O, such as the concentric circles 11a and radial lines 11b of the sighting plate 11.

[0036] Next, the amount of eccentricity at an arbitrary position of the casing pipe 3 will be specifically described with reference to FIGS. 6 to 9, based on the waxing and waning of the image of the pattern photographed by the camera 21 and the displacement of the photographing center position O. FIG.

[0037] Fig. 6 is a front view showing the eccentricity of a casing pipe to which the linearity accuracy measuring device of Fig. 1 is applied. Fig. 7 is an explanatory diagram showing the eccentricity of a casing pipe at depths (1) to (5) and images of those depths, using the linearity accuracy measuring device of Fig. 1. Fig. 8 is an explanatory diagram showing the eccentricity of a casing pipe at depths (6) to (10) and images of those depths, using the linearity accuracy measuring device of Fig. 1. Fig. 9 is an explanatory diagram showing the eccentricity of a casing pipe at depths (11) to (15) and images of those depths, using the linearity accuracy measuring device of Fig. 1.

[0038] 7 to 9 are schematic model diagrams showing the positional relationship between an origin position (HP) image when the movable member 10 is moved from the origin position (HP) to a predetermined depth and an image of the pattern at the measurement depth position of the sighting plate 11. Although the size of the image captured by the camera 21 decreases as the measurement position deepens, in FIGS. 7 to 9, the camera 21 is provided with an autofocus function to adjust the captured image so that it does not become small, and the image is displayed on the display unit 32, making it easier to determine the state of defects in the captured image. The origin position (HP) image is an image of the sighting plate 11 captured by the camera 21 at a position where the casing pipe 3 is not eccentric at all.

[0039] Furthermore, Fig. 6 shows an example in which images are taken at intervals of 1 m at the measurement depth inside the casing pipe 3, and this is repeated up to the planned depth of 15 m. Also, (1) to (15) in Figs. 7 to 9 show the eccentricity state of the casing pipe 3 at intervals of 1 m from the depth of 1 m to the planned depth of 15 m, and images at those depths.

[0040] As shown in Figures 6 and 7, from depths (1) to (3), the casing pipe 3 does not bend (eccentricity), so the images at those depths are perfectly circular images, which are the origin position (HP) images. From depths (3) to (4), the casing pipe 3 is eccentric to the right by 48 mm relative to the axis C, resulting in an image with a missing right side compared to the origin position (HP) image. From depths (4) to (5), the casing pipe 3 is eccentric to the right by 77 mm relative to the axis C, and from depths (5) to (6) shown in Figure 7, the casing pipe 3 is eccentric to the right by 87 mm relative to the axis C, resulting in an image with a missing right side compared to the origin position (HP) image. In Figures 8 and 9, the circle designated RP indicates the position of the image when the casing pipe 3 is eccentric to the farthest right relative to the axis C. Similarly, the circle designated LP indicates the position of the image when the casing pipe 3 is eccentric to the farthest left relative to the axis C.

[0041] From depth (6) to (7), the image is offset 77 mm to the right from the axis C, i.e., it returns 10 mm from depth (6) to the left toward the axis C, resulting in an image with less loss on the right side and a small loss on the left side compared to the image at the origin position (HP). From depth (7) to (8), the image is offset 48 mm to the right from the axis C, i.e., it returns 39 mm from depth (6) to the left, resulting in an image with even less loss on the right side and even more loss on the left side compared to the axis C. From depth (8) to (9), the image returns to the center position, and the image at those depths is missing on the left side.

[0042] Depths (9) to (10) are offset 54 mm to the left from the axis C, and the images at those depths are further missing on the left side. Depths (10) to (11) are offset 86 mm to the left from the axis C, and are 86 mm from the axis C, and the images at those depths are further missing on the left side. Depths (11) to (12) are offset 97 mm to the left from the axis C, and are 97 mm from the axis C, and the images at those depths are further missing on the left side.

[0043] From depth (12) to (13), the image is 86 mm off-center to the left with respect to the axis C, that is, it moves back 97 - 86 = 11 mm to the right, and the image at that depth is even less chipped on the left side and slightly chipped on the right side. From depth (13) to (14), the image is 54 mm off-center to the left with respect to the axis C, and the image at that depth is even more chipped on the left side and the chipped part on the right side is larger. Then, from depth (14) to (15), the image returns to the center position, and the image at that depth is even more chipped on the left and right sides (the same part when RP and LP are superimposed).

[0044] In this way, it is possible to measure the direction and amount of eccentricity at any position of the casing pipe 3 based on the waxing and waning of the image of the pattern of the concentric circles 11a and the radial lines 11b.

[0045] Furthermore, if measurements using regular patterns are repeated as in this embodiment, in the future it will be possible to switch to an AI estimation method by using the results of comparing the estimated values ​​from the captured images with the actual measured displacement of the casing pipe 3 as training data for AI (artificial intelligence), making it possible to estimate using simpler patterns.

[0046] Thus, according to this embodiment, the control unit 31 is configured to determine the axial eccentricity state of the casing pipe 3 based on at least one of the defect state of the captured image of the movable member 10 captured by the camera 21 at a distance from the opening end 3a of the casing pipe 3 and the deviation from the imaging center position O. This simplifies the structure, makes it easy to determine the linear accuracy of the casing pipe 3, and increases versatility.

[0047] Furthermore, according to this embodiment, the movable member 10 is formed in a cylindrical shape having a predetermined length, so that the movable member 10 can always be moved stably along the axis C of the casing pipe 3.

[0048] In addition, according to this embodiment, the aiming plate 11 has a plurality of LED lights, which are arranged in a plurality of concentric circles at regular intervals from the shooting center position 26 of the aiming plate 11, and are also arranged in a plurality of radial circles from the shooting center position 26, and the eccentricity state of the casing pipe 3 can be determined based on at least one of the missing parts in the images of the plurality of concentric circles 11a and the plurality of radial lines 11b of the plurality of LED lights captured by the camera 21, and the superposition of the captured image at the pipe mouth with the captured image at each depth, so it becomes possible to easily determine in what direction and to what extent the axis C of the casing pipe 3 is deviated from the linear direction.

[0049] Furthermore, according to this embodiment, the camera 21 is a camera with an autofocus function, and the lens 25 of this camera 21 is provided with perpendicular crosshairs, so that the horizontal and vertical positions of the image captured by the camera 21 can be easily identified, making it even easier to identify the linear accuracy of the casing pipe 3.

[0050] In this embodiment, the moving member 10 is provided with a collimation plate 11, and the collimation plate 11 is made to emit LED lights in multiple concentric circles at regular intervals from the center position O of the collimation plate 11, and in multiple radial directions from the imaging center position O. However, it is also possible to provide a reflective pattern on the rear end surface of the moving member in the movement direction, not limited to the collimation plate 11, specifically, a reflective surface that reflects in multiple concentric circles at regular intervals from the imaging center position O and in multiple radial directions from the imaging center position O, as in the above embodiment, and to install a light source (not shown) at the opening end 3a, irradiate light from this light source, and discern the reflected image. This reflection form uses retroreflection, which returns most of the light irradiated from the light source back to the light source.

[0051] With this configuration, it is possible to easily determine in what direction and to what extent the axis C of the casing pipe 3 is displaced from the linear direction.

[0052] [Second embodiment] 10 is a schematic perspective view showing a linear accuracy measuring device according to a second embodiment of the present invention. Note that the same reference numerals are used for the same or corresponding parts to those in the first embodiment, and different configurations and functions will be described.

[0053] The linearity accuracy measuring device 1A according to this embodiment is installed horizontally within the casing pipe 3 so that the movable member 10A cannot fall freely. As shown in FIG. 10 , the movable member 10A is equipped with a drive mechanism 40, which rotates and drives a running wheel 41, allowing the movable member 10A to move forward and backward within the casing pipe 3. The drive mechanism 40 is controlled so that it can be driven or stopped via wireless transmission and reception. The drive mechanism 40 may be provided separately from the movable member 10 and connected to the movable member 10 by a string-like object such as a wire, and the movable member 10 may be pulled by driving the drive mechanism 40. Furthermore, as a means for moving the movable member 10A, if the casing pipe 3 has an open end 3b on the opposite side of the open end 3a and penetrates in the axial direction, the movable member 10A may be pulled from the open end 3b.

[0054] In this embodiment, the casing pipe 3 is not limited to being horizontal, but can also be applied to a case where it is installed on an upward gradient.

[0055] As described above, according to this embodiment, the movable member 10A is provided with the drive mechanism 40 that allows it to move freely along the axial direction on the inner peripheral side of the casing pipe 3, so even if the casing pipe 3 is disposed horizontally or on an upward gradient, the movable member 10A can be moved along the axial direction on the inner peripheral side of the casing pipe 3. As a result, it is possible to further increase versatility.

[0056] [Another embodiment of the invention] Although one embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This embodiment can be embodied in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. This embodiment is included within the scope and spirit of the invention, as well as within the scope of the inventions described in the claims and their equivalents.

[0057] In the first embodiment, an example was described in which the casing pipe 3 was eccentric in the left-right direction relative to the axial direction, but this is not limited to this, and it is possible to measure the degree of eccentricity in any direction, up, down, left, or right. [Explanation of symbols]

[0058] 1. Linear accuracy measuring device 2 underground 3. Casing pipe (tubular body) 3a Open end (tube opening) 3b Open end (tube opening) 4 Inner rod 10 Moving parts 11. Sighting plate 11a Concentric Circles 11b Radiation 20 Measuring device (measuring means) 21 Camera (imaging means) 22 Interior Space 23 Winding and unwinding member 24 Hanging cord 25 lenses 30 Length measurement mechanism 31 Control unit (discrimination means) 32 Display section 33 Storage section 40 Drive mechanism 41 Running wheel C axis center O Image capture center position

Claims

1. a measuring means for measuring the eccentricity state at each position in the axial direction of the tubular body buried in the ground; a storage means for storing the eccentricity state at each axial position of the tubular body measured by the measuring means; a display means for displaying the bending state of the tubular body in the entire axial direction based on the eccentricity state at each position in the axial direction stored in the storage means; and A linear accuracy measuring device comprising:

2. the measuring means has an imaging means for capturing an image of the eccentricity state at each position in the axial direction of the tubular body, 2. The linear accuracy measuring device according to claim 1, wherein the image of the eccentricity state at each position of the tubular body captured by the imaging means is displayed on the display means.

3. a moving member provided on the inner periphery of the tubular body so as to be movable along the axis of the tubular body, the rear end surface of which in the moving direction serves as an identification surface; The measuring means an imaging means for capturing an image of the discrimination surface when the moving member moves along the axial direction of the tubular body; a determination means for determining an eccentricity state of the tubular body in the axial direction based on at least one of a defect state of an image captured at an arbitrary distance by which the moving member has moved from the open end of the tubular body and a deviation of an image center position, with respect to an origin position image captured by the imaging means at a position where the tubular body is not eccentric; and 2. The linear accuracy measuring device according to claim 1, further comprising:

Images