Inspection system and inspection method for columnar structures

Abstract

The present invention provides a photographic medium, a soft case, an inspection system, and an inspection method that can obtain clear images of the inside of a columnar structure without being damaged, even at locations where attachments are mounted on the columnar structure. [Solution] The imaging medium 3 comprises an imaging plate on which a photostimulable phosphor is coated on a plastic plate, and a soft case formed to allow X-rays to pass through and which houses and protects the imaging plate. Both the imaging plate and the soft case are formed to be deformable to conform to the shape of the reinforced concrete column P.

Description

Technical Field

[0001] The present invention relates to a photographing medium for a columnar structure, a soft case, an inspection system, and an inspection method.

Background Art

[0002] A method for nondestructively inspecting whether the internal reinforcing bars of a reinforced concrete column are broken is used. For example, Patent Document 1 discloses a nondestructive inspection device in which a photographing panel for detecting X-rays and a shielding plate for shielding X-rays are configured to be bendable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The nondestructive inspection device of Patent Document 1 can reduce the distance between the photographing panel and the reinforced concrete column by bending the photographing panel. The photographing panel is composed of a flat panel detector in which a large number of photodiodes and pixel circuits for driving each photodiode are arranged on a resin substrate. Therefore, there are restrictions on the direction in which the photographing panel can be bent, and at locations where attachments such as metal bands and electric wires are attached to the reinforced concrete column, the photographing panel cannot be bent properly. And if an attempt is made to bend the photographing panel forcibly, the photodiodes and pixel circuits will be damaged this time. Such problems exist not only when inspecting the internal reinforcing bars of a reinforced concrete column, but also when inspecting other columnar structures such as steel pipe columns.

[0005] This invention is based on the above background and aims to provide a photographic medium, a soft case, an inspection system, and an inspection method that can obtain clear images of the inside of a columnar structure without being damaged even at locations where attachments are attached to the columnar structure. [Means for solving the problem]

[0006] To achieve the above objective, the photographic medium according to the present invention is An imaging plate in which a photostimulable phosphor is coated on a plastic plate, It comprises a soft case formed to be permeable to radiation, which houses and protects the imaging plate inside, Both the imaging plate and the soft case are formed to be deformable to conform to the shape of the columnar structure. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a photographic medium, a soft case, an inspection system, and an inspection method that can obtain clear images of the inside of a columnar structure without being damaged, even at locations where attachments are attached to the columnar structure. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the configuration of an inspection system according to an embodiment of the present invention. [Figure 2] (a) and (b) are diagrams showing the configuration of the imaging medium according to embodiments of the present invention. [Figure 3] This is another diagram showing the configuration of an inspection system according to an embodiment of the present invention. [Figure 4] This is a cross-sectional view showing how the internal reinforcing bars of a reinforced concrete column are photographed using the inspection system according to an embodiment of the present invention. [Figure 5] This figure illustrates a method for determining whether internal reinforcing bars are located on the front or back side of the X-ray generator in an image captured by an inspection system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0009] The following describes in detail, with reference to the drawings, the photographic medium, soft case, inspection system, and inspection method for columnar structures according to embodiments of the present invention. In each drawing, the same or equivalent parts are denoted by the same reference numerals.

[0010] The inspection system according to this embodiment is a system that irradiates a columnar structure with X-rays from an X-ray generator and detects the X-rays that have passed through the columnar structure with an imaging medium to image the inside of the columnar structure. By checking the appearance of the inside of the columnar structure as depicted in the image read from the imaging medium, the user can determine whether there is corrosion or damage inside the columnar structure.

[0011] The columnar structure according to this embodiment is a columnar structure installed on the ground that supports an object to be supported, such as an electric wire, above the ground level. Examples of columnar structures according to this embodiment include reinforced concrete columns and steel pipe columns. The following explanation will use a reinforced concrete column as the object of inspection and will describe the case of inspecting whether the internal reinforcement of the reinforced concrete column is fractured as an example.

[0012] A reinforced concrete pole is a slender structure made of reinforced concrete, used, for example, as a utility pole for carrying power lines. A reinforced concrete pole comprises a cylindrical concrete body and multiple internal reinforcing bars provided within the concrete body, arranged in a circular direction around the reinforced concrete body and extending in the longitudinal direction. The outer diameter of the reinforced concrete pole may gradually increase from the top to the bottom, or it may remain the same diameter.

[0013] Next, the configuration of the inspection system 1 according to the embodiment will be described with reference to Figures 1 to 3. As shown in Figure 1, the inspection system 1 comprises an X-ray generator 2 installed facing the reinforced concrete column P and generating X-rays that penetrate the reinforced concrete column P, and an imaging medium 3 installed together with the X-ray generator 2 so as to sandwich the reinforced concrete column P. The pair of the X-ray generator 2 and the imaging medium 3 are installed facing each other with the reinforced concrete column P in between.

[0014] The X-ray generator 2 is a radiation generator that generates X-rays, an example of radiation, and irradiates an external target with them. The X-ray generator 2 is configured to be portable by the user and is installed on a stand 2A or the like, which is adjusted to the height of the area to be inspected. The X-ray generator 2 is equipped with an X-ray tube. In the X-ray tube, electrons emitted from a filament collide with the target, thereby generating X-rays from the target. The X-ray generator 2 may be powered by an external power supply or by a battery.

[0015] When inspecting areas where attachments are installed on reinforced concrete poles P, it is advisable to increase the tube voltage or irradiation time in the X-ray generator 2, while considering the effective dose to workers, in order to secure the equivalent dose necessary for imaging. An example of an attachment to a reinforced concrete pole P is a metal band B (utility pole band) attached around the reinforced concrete pole P. The following explanation will use the case where band B is used as the attachment as an example.

[0016] The imaging medium 3 is irradiated by the X-ray generator 2 and detects the X-rays that have passed through the reinforced concrete column P. The imaging medium 3 is a deformable imaging medium formed in a plate shape and can be bent by hand to match the outer wall of the reinforced concrete column P. Furthermore, since the imaging medium 3 does not have any electronic components or circuits attached to it, it can be deformed into any shape. For this reason, even if a band B is attached to the reinforced concrete column P, it can be deformed to match the shape of the band B, and the part of the imaging medium 3 that is not in contact with the band B can be fitted to the surface of the reinforced concrete column P.

[0017] As shown in FIG. 2, the imaging medium 3 includes an imaging plate (IP) 3A and a soft case 3B that is formed to be radiation-permeable and houses and protects the imaging plate 3A therein. The imaging medium 3 may be attached to the surface of the reinforced concrete column P with an adhesive tape or a rope.

[0018] The imaging plate 3A is a thin and flexible plate that can record an image of a detection object when irradiated with radiation. The imaging plate 3A is formed by coating a plastic film with a phosphor (scintillating phosphor) that produces afterglow. The scintillating phosphor has the property of emitting light again when irradiated with light having a wavelength longer than the emission wavelength after the emission due to the irradiation of radiation has ended. The plastic film is formed of, for example, polyethylene terephthalate resin, and the scintillating phosphor may be applied or vapor-deposited on this plastic film.

[0019] The soft case 3B is a protective case that is formed to be deformable according to the shape of the reinforced concrete column P and protects the imaging plate 3A from being damaged. The soft case 3B is formed of a flexible sheet that is radiation-permeable and has flexibility. Since the imaging medium 3 is used outdoors even in rainy weather, the sheet is formed of a material having dust-proof, waterproof, and weather-resistant properties, such as rubber or a thermoplastic elastomer (e.g., silicone rubber). The thickness of the sheet is set such that it does not prevent the deformation of the imaging plate 3A and is not easily damaged even when repeatedly bent. The thickness of the sheet is, for example, within the range of 0.1 mm to 5 mm, preferably within the range of 1 mm to 2 mm, and is, as an example, 1.3 mm. [[ID=?]]

[0020] The soft case 3B is formed, for example, like an envelope. Specifically, the soft case 3B has its lower end and both side ends sealed in a state where two sheets are overlapped, and an opening for inserting and removing the imaging plate 3A is provided at the upper end. A flap capable of sealing the opening in a closed state is provided at the upper end portion of the soft case. [[ID=?]] [[ID=?]]

[0021] It should be noted that there are some tags in the original text that seem to be incomplete or incorrect in terms of the tag format (e.g., etc. which may not be standard in a proper context). I've translated them as they are while maintaining the overall integrity of the translation. Also, there are some consecutive tags with the same number in the original which might need to be checked for accuracy in the source material context. As shown in Figure 3, the inspection system 1 further comprises a computed radiography (CP) system 4 and a display device 5. The computed radiography system 4 and the display device 5 are communicated together via a wired or wireless communication circuit.

[0022] Computed radiography 4 is a scanner that generates photostimulable fluorescence by irradiating an imaging plate 3A, which has been irradiated with X-rays, with excitation light, and reads the image recorded on the imaging plate 3A. In computed radiography 4, excitation light is scanned across the imaging plate 3A, the light generated by the irradiation of laser light is converted into an analog signal by an optical sensor, the analog signal is converted into a digital signal, and a two-dimensional captured image is generated by applying signal processing to the digital signal. The excitation light is, for example, laser light, and the optical sensor is, for example, a photomultiplier tube.

[0023] The display device 5 is, for example, a general-purpose computer. The display device 5 comprises an operating device, a display, an input / output interface, memory, and a processor. By executing a program stored in memory, the input / output interface stores the captured image data received from the computed radiography 4 into memory, and displays the captured image on the display based on the operation signal from the operating device operated by the user.

[0024] Because the inspection system 1 has the above configuration, it can be curved to conform to the curved surface of the reinforced concrete column P. As a result, a large number of reinforcing bars can be photographed in a single shot, reducing the number of shots required. In the example shown in Figure 4, the X-ray generator 2 is installed away from the reinforced concrete column P, and the X-rays are made to penetrate all of the internal reinforcing bars, so all eight internal reinforcing bars are photographed. Furthermore, because the gap between the imaging plate 3A and the reinforced concrete column P is small, clear images can be obtained even at both ends of the imaging plate 3A, and clear images can be obtained even when band B is installed on the reinforced concrete column P. In addition, because the gap between the imaging plate 3 and the reinforced concrete column P is small, it is easy to attach the imaging medium 3 to the reinforced concrete column P. The above describes the configuration of inspection system 1.

[0025] Next, a method for determining the imaging procedure using the inspection system 1 according to the embodiment will be described. The inspection target area by the inspection system 1 is the area on the surface of the reinforced concrete column P where cracks or fractures have been confirmed. The imaging direction and the number of imaging sessions are determined after understanding the arrangement of internal reinforcement at the inspection target area using the reinforcement drawing. The imaging direction indicates where the pair of X-ray generator 2 and imaging medium 3, which are installed facing each other, should be placed around the reinforced concrete column P.

[0026] In imaging using the inspection system 1 according to the embodiment, one imaging session is performed in principle. In a single imaging session, the pair of the X-ray generator 2 and imaging medium 3 are positioned so that all the reinforcing bars on both the front and back sides of the X-ray generator 2 can be imaged in one session, taking into consideration the arrangement of the internal reinforcing bars. At this time, the imaging medium 3 is installed so as to minimize the gap between it and the reinforced concrete column P and the band B. For example, when imaging the portion of the reinforced concrete column P to which the band B is attached, the imaging medium is positioned so as to avoid the bolt protrusions of the band B as much as possible.

[0027] As shown in Figure 5, the images obtained using this procedure show that the internal reinforcing bars on the near side of the X-ray generator 2 appear thicker than those on the far side. This is because the X-rays emitted from the X-ray generator 2 are irradiated radially, so objects closer to the X-ray generator 2 appear larger in the image. This allows the circumferential position of each internal reinforcing bar to be identified from a single image.

[0028] If, after the first imaging, there are reinforcing bars that could not be imaged due to the influence of band B, the pair of X-ray generator 2 and imaging medium 3 should be rotated within a range of less than 90° around the long axis of the reinforced concrete column P, and a second imaging should be performed.

[0029] On the other hand, if a decrease in image quality is expected with a single exposure due to the installation of band B, the procedure should be to perform two or more exposures from the beginning. An example of when a decrease in image quality is expected is when the gap between the imaging plate 3A and the reinforced concrete column P becomes larger due to the bolt protrusions of band B. In this case, the first exposure is performed in the same way as a single exposure. Next, for the second exposure, the pair of X-ray generator 2 and imaging medium 3 is rotated and positioned within a range of less than 90° around the long axis of the reinforced concrete column P from the arrangement used for the first exposure. When performing a third exposure, the pair of X-ray generator 2 and imaging medium 3 is rotated and positioned 180° around the long axis of the reinforced concrete column P from the arrangement used for the first exposure. The above describes how to determine the shooting procedure.

[0030] Next, a method for inspecting the internal reinforcement of a reinforced concrete column P using the inspection system 1 according to the embodiment will be described. It is assumed that the procedure for photographing the reinforced concrete column P has been determined before implementing the inspection method. First, prepare the imaging medium 3. Specifically, the imaging plate 3A, from which the image has been erased, is placed inside the soft case 3B, and the opening is sealed with a flap to assemble the imaging medium 3.

[0031] Next, the imaging medium 3 is attached while deforming it to match the shape of the reinforced concrete column P and band B so that the imaging direction is determined in the imaging procedure, and the X-ray generator 2 is installed so as to face the imaging medium 3 with the reinforced concrete column P in between. If there are sharp attachments such as wires attached to the area to be imaged, it is preferable to remove these attachments in advance so as not to damage the soft case.

[0032] Next, the internal reinforcement of the reinforced concrete column P is photographed. Specifically, X-rays are irradiated from the X-ray generator 2 so that they pass through the reinforced concrete column P and head toward the imaging medium 3, thereby recording an image of the internal reinforcement of the reinforced concrete column P onto the imaging medium 3.

[0033] Next, remove the imaging medium 3 from the reinforced concrete column P, and take out the imaging plate 3A from the soft case 3B.

[0034] Next, the imaging plate 3A is placed in the computed radiography 4, and the computed radiography 4 is instructed to read an image from the imaging plate 3A. The image read by the computed radiography 4 is transmitted to the display device 5 and stored in its memory.

[0035] By repeating the above procedure according to the number of shots determined by the shooting procedure, the image of the internal reinforcing steel recorded on each imaging plate 3A is converted into a captured image, and the captured images corresponding to the number of shots are sequentially stored in the memory of the display device 5. The user simply needs to read the captured images stored in the memory of the display device 5 and display them on the display of the display device 5. Then, by referring to one or more captured images displayed on the display of the display device 5, the user can determine whether or not the internal reinforcing steel is fractured at the inspection site. The above is the flow of the testing procedure.

[0036] As described above, the imaging medium 3 according to the embodiment comprises an imaging plate 3A on which a photostimulable phosphor is coated on a plastic plate, and a soft case 3B formed to allow X-rays to pass through and housing and protecting the imaging plate 3A. Both the imaging plate 3A and the soft case 3B are formed to be deformable to conform to the curvature of the outer wall of the reinforced concrete column P. Therefore, even in areas where attachments such as bands B are attached to the reinforced concrete column P, the imaging medium will not be damaged, and a clear image of the inside of the reinforced concrete column P can be obtained.

[0037] The present invention is not limited to the embodiments described above, and the following modifications are also possible.

[0038] (modified version) In the above embodiment, X-rays were used as the radiation, but the present invention is not limited thereto. For example, depending on the type of reinforced concrete column P, neutron rays or gamma rays may be used as the X-rays.

[0039] In the above embodiment, the X-ray generator 2 was placed on a stand 2A, but the present invention is not limited to this. For example, the X-ray generator 2 may be placed on a trolley to facilitate transportation.

[0040] In the above embodiment, the soft case 3B was attached to the reinforced concrete column P with adhesive tape or rope, but the present invention is not limited thereto. For example, a pair of bands extending from both ends of the soft case 3B may be attached, and both ends of the pair of bands may be made detachable with hook-and-loop fasteners or the like, so that the pair of bands and the soft case 3B are wrapped around the reinforced concrete column P.

[0041] In the above embodiment, the soft case 3B was formed like an envelope, but the present invention is not limited to this. For example, a zipper may be provided instead of the flap at the top. Also, if dustproof or waterproof properties are not required, the flap at the top of the soft case 3B may be omitted and it may be formed in the shape of a bag.

[0042] In the above embodiment, the imaging plate 3A was housed in a soft case 3B, but the present invention is not limited to this. For example, an X-ray film may be housed in the soft case 3B.

[0043] In the above embodiment, the inspection system 1 was used to inspect whether the internal reinforcement of the reinforced concrete column P was fractured, but the present invention is not limited to this. For example, the inspection system 1 may also be used to inspect whether corrosion deterioration is occurring inside a steel pipe column. In areas where corrosion deterioration is occurring inside a steel pipe column, the thickness of the pipe wall is reduced, so it can be distinguished from normal areas where corrosion deterioration is not occurring in the captured image.

[0044] The embodiments described above are illustrative, and the present invention is not limited thereto. Various embodiments are possible without departing from the spirit of the invention as described in the claims. The components described in the embodiments and modifications can be freely combined. Furthermore, inventions equivalent to the invention described in the claims are also included in the present invention. [Explanation of symbols]

[0045] 1. Inspection System 2 X-ray generator 3. Shooting medium 3A Imaging Plate 3B Soft Case P Reinforced concrete column

Claims

1. An imaging plate in which a photostimulable phosphor is coated on a plastic plate, It comprises a soft case formed to be permeable to radiation, which houses and protects the imaging plate inside, Both the imaging plate and the soft case are formed to be deformable to conform to the shape of the columnar structure. The medium used for photography.

2. A soft case for housing and protecting an imaging plate in which a photostimulable phosphor is coated on a plastic plate, It is capable of transmitting radiation and is formed to be deformable to conform to the shape of a columnar structure. Soft case.

3. An inspection system for inspecting the interior of a columnar structure, The photographic medium described in claim 1, A radiation generating device that generates radiation that penetrates the columnar structure and is directed toward the imaging medium, An inspection system equipped with the following features.

4. An inspection method for inspecting the interior of a columnar structure, A step of preparing the photographic medium described in claim 1, The process involves attaching the imaging medium while deforming it to match the shape of the columnar structure, and installing a radiation generating device so as to face the imaging medium with the columnar structure in between. The process of irradiating the columnar structure with radiation from the radiation generating device so that the radiation passes through it and is directed toward the imaging medium, Testing methods including those mentioned.

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