Inspection device, inspection system, and inspection method

Abstract

To provide an inspection device capable of accurately inspecting the presence or absence of a crack with improved efficiency.SOLUTION: An inspection device 10 for inspecting a crack C of a structure includes a control part 15. The control part 15 acquires a temperature distribution at an object portion P1 for inspecting the crack C on the basis of infrared radiant energy which is generated from a surface of the object portion P1 when a periphery of the object portion P1 is locally heated from the inside of the structure, so as to determine the presence or absence of the crack C on the basis of the acquired temperature distribution.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to an inspection apparatus, an inspection system, and an inspection method. [Background Art]

[0002] In a conventional iron-making process, raw materials including iron ore, coal, and the like are transported by a bulk carrier. After arriving at an ironworks, the raw materials are unloaded to a yard using an unloader crane. The unloader crane includes two traveling girders and a grab self-propelled trolley that travels on the traveling girders. The grab self-propelled trolley includes a grab that moves vertically and opens and closes. The grab self-propelled trolley lowers the grab into the hold of the bulk carrier to grip the raw material in the hold, and then lifts the grab. The grab self-propelled trolley further moves the grab over a raw material conveyance line, opens the grab, and drops the raw material gripped by the grab. By repeating the above-described operations, the unloader crane unloads the raw material from the bulk carrier to the yard.

[0003] Each time the grab self-propelled trolley travels on the traveling girder, a wheel load corresponding to the sum of the self-weight of the grab self-propelled trolley, the weight of the grab, and the weight of the raw material in the grab repeatedly acts on the traveling girder. Fatigue cracks may occur in the traveling girder due to this repeated action of loading and unloading. If the traveling girder breaks due to a crack, accidents such as the fall of the grab self-propelled trolley and the falling of the traveling girder into the sea may occur, resulting in extremely severe damage. In addition, the operation of the ironworks is stopped because raw materials cannot be unloaded.

[0004] To avoid the above situation, crack inspection of traveling girders is performed. For example, color check, magnetic particle testing, ultrasonic testing, and the like have been conventionally used as inspection methods. However, in methods such as color check, magnetic particle testing, and ultrasonic testing, workers have had to approach the inspection target site to perform the necessary procedures for each method.

[0005] For example, in magnetic particle testing, it was necessary for workers to remove rust and dirt from the area to be inspected to prepare a surface suitable for measurement before applying a magnetic field to the area. Therefore, scaffolding had to be erected using an unloader crane, preparations for working at heights had to be made, and the work could not be carried out unless the area to be inspected was within reach of the workers. As a result, more manpower and money were spent on setting up scaffolding and other preparations than on the actual work of inspecting defects such as cracks.

[0006] Under these circumstances, in recent years, crack inspection methods using infrared thermography, which can inspect a wide area remotely, simultaneously, and easily, have attracted attention. This method is called the active infrared method and involves applying some kind of input to a crack and detecting its thermal reaction. Conventionally, various crack inspection methods utilizing the active infrared method have been proposed. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 4803652 [Patent Document 2] Patent No. 6079098 [Patent Document 3] Japanese Patent Publication No. 2019-78550 [Overview of the project] [Problems that the invention aims to solve]

[0008] As an example of a conventional crack inspection method using the active infrared method, a structural defect detection method described in Patent Document 1 is known. This method utilizes stress fluctuations in the crack caused by the weight of the crane trolley and the weight of the suspended load when the load is moved by the crane. This method measures the instantaneous stress concentration heat generated in the crack using infrared thermography equipment, enabling remote crack inspection.

[0009] However, temperature fluctuations due to stress changes during crane movement are very short-lived and minute. Because steel has high thermal conductivity, temperature fluctuations at cracks immediately diffuse and disappear. Therefore, it was necessary to use a cooled infrared thermography camera capable of high-speed and high-precision measurement. However, cooled infrared thermography cameras are very expensive as equipment and are very large in size because they have a cooling device inside the camera.

[0010] In addition, since the measurement utilizes stress fluctuations during operation, measurements can only be taken when the crane is in operation. However, for safety reasons, it is difficult to approach the crane when it is in operation, so it was necessary to take measurements from a distance using a telephoto lens. Telephoto lenses are very expensive. Furthermore, with remote measurements, it was difficult to perform crack inspections on target areas that were blind spots for the camera, such as behind the crane's trolley.

[0011] As an example of a conventional crack inspection method using the active infrared method, the crane crack diagnosis method described in Patent Document 2 is also known. In this method, ultrasonic vibrations are applied to the traveling girder of the crane using an ultrasonic vibrator, and the frictional heat at the crack surface is used to heat the crack, which is then detected by measuring it from the ground with infrared thermography.

[0012] However, this method required fixing the ultrasonic vibration device to the sliding girder and applying pressure to the girder in order to apply ultrasonic vibrations. Therefore, when inspecting multiple target areas, moving the device took time, resulting in low inspection efficiency. Furthermore, if there was space or small components in the propagation path of the ultrasonic vibration between the ultrasonic vibration device and the target area being inspected, the ultrasonic vibration would not propagate accurately. Consequently, if crack heating could not be confirmed, it was difficult to determine whether it was due to poor ultrasonic vibration propagation or whether the area was sound and no crack existed, leading to a risk of overlooking cracks.

[0013] As an example of a conventional crack inspection method using the active infrared method, the crack detection method described in Patent Document 3 is also known. In this method, infrared radiation irradiated from the surrounding environment and reflected from the surface of the area to be inspected is measured by infrared thermography. Cracks are detected by utilizing the fact that differences in the intensity of infrared reflection occur based on the surface condition of the area to be inspected.

[0014] However, this method had the problem of being difficult to apply when a coating was applied to the surface of the target area, or when it was necessary to detect small fatigue cracks of a size that would not easily show differences in surface condition.

[0015] This disclosure has been made in view of the above-mentioned problems, and aims to provide an inspection device, inspection system, and inspection method that can inspect for the presence or absence of cracks more efficiently and accurately. [Means for solving the problem]

[0016] (1) An inspection apparatus according to one embodiment of the present disclosure An inspection device for inspecting cracks in structures, Equipped with a control unit, The control unit obtains a temperature distribution at the target area based on the infrared radiation energy generated from the surface of the target area when the area surrounding the target area to be inspected for cracks is locally heated from inside the structure, and determines the presence or absence of the crack based on the obtained temperature distribution.

[0017] (2) As one embodiment of the present disclosure, in (1), The control unit may determine the presence or absence of the crack based on a first image showing the temperature distribution, which is output from the imaging device that detects the infrared radiation energy.

[0018] (3) As one embodiment of the present disclosure, in (2), The control unit may determine the presence or absence of the crack based on the pattern of the temperature profile on the line in the first image.

[0019] (4) According to one embodiment of the present disclosure, in (2) or (3), The control unit may determine the presence or absence of a crack based on a second image showing a temperature gradient distribution calculated by performing differentiation processing on the first image.

[0020] (5) According to one embodiment of the present disclosure, in any one of (1) to (4), The control unit may acquire the temperature distribution based on the infrared radiation energy corresponding to a measurement wavelength of 1 μm to 20 μm.

[0021] (6) According to one embodiment of the present disclosure, in any one of (1) to (5), The structure includes a crane having a traveling girder, The control unit may acquire the temperature distribution based on the infrared radiation energy emitted from the surface of the target portion when the periphery of the target portion is locally heated from inside the traveling girder.

[0022] (7) An inspection system according to one embodiment of the present disclosure includes: the inspection device according to any one of (1) to (6), a heating device configured to locally heat the periphery of the target portion from inside the structure, an imaging device configured to detect the infrared radiation energy, and .

[0023] (8) According to one embodiment of the present disclosure, in (7), The heating device may include at least one of a lamp, a hot air source, a spray source, a laser light source, and a heater.

[0024] (9) According to one embodiment of the present disclosure, in (8), The heating device may locally heat the periphery of the target portion from the back side of the target portion located inside the structure.

[0025] (10) An inspection method according to one embodiment of the present disclosure comprises: A method for inspecting cracks in structures, A heating step in which the area to be inspected for the crack is locally heated from the inside of the structure, An acquisition step to acquire the temperature distribution at the target part based on the infrared radiation energy generated from the surface of the target part by the heating step, A determination step in which the presence or absence of the crack is determined based on the temperature distribution obtained in the acquisition step, Includes. [Effects of the Invention]

[0026] According to an inspection apparatus, inspection system, and inspection method according to one embodiment of this disclosure, it is possible to inspect for the presence or absence of cracks more efficiently and accurately. [Brief explanation of the drawing]

[0027] [Figure 1] This is a schematic side view showing a crane on which an inspection system according to one embodiment of the present disclosure is installed. [Figure 2] Figure 1 is a top view of the crane. [Figure 3] Figure 1 is a schematic cross-sectional perspective view showing the structure of the traveling girder. [Figure 4] Figure 1 is a schematic enlarged cross-sectional view showing what happens when a crack occurs in the traveling girder. [Figure 5] Figure 4 is a schematic diagram of the crack as seen from the front of the inner web plate. [Figure 6] Figure 2 is a schematic diagram showing an example of the configuration of the inspection system installed on the traveling girder. [Figure 7] This block diagram shows an example of the configuration of the inspection device shown in Figure 6. [Figure 8] Figure 6 is a flowchart showing an example of an inspection method performed by the inspection system. [Figure 9] This is a schematic diagram showing the first example of the first image acquired in step S102 of Figure 8. [Figure 10]This is a schematic diagram showing a second example of the first image acquired in step S102 of Figure 8. [Figure 11] This graph shows the temperature line profile of the first image acquired in step S102 of Figure 8. [Figure 12] This is a schematic diagram showing an example of the second image acquired in step S103 of Figure 8. [Figure 13] This is a schematic diagram showing an example of the configuration of an inspection system relating to a modified example of this disclosure. [Modes for carrying out the invention]

[0028] In the following, one embodiment of this disclosure will be mainly described with reference to the attached drawings.

[0029] Figure 1 is a schematic side view showing a crane 100 on which an inspection system 1 according to one embodiment of the present disclosure is installed. Figure 2 is a top view of the crane 100 in Figure 1. The inspection system 1 according to one embodiment is installed on the crane 100 and inspects for cracks in the crane 100. The crane 100 includes, as an example, an unloader crane that unloads raw materials 108 such as iron ore from a bulk carrier.

[0030] As shown in Figure 1, the crane 100 unloads raw materials 108, such as iron ore, transported from overseas by bulk carriers, into the yard after the bulk carriers arrive at the steel mill. The crane 100 has a traveling girder 101 and a self-propelled trolley 106 that travels on the traveling girder 101. The traveling girder 101 is connected to land-side supports 102 and sea-side supports 103. To reduce its deflection, the traveling girder 101 is supported by a number of tension bars 104 connected to the land-side supports 102 and sea-side supports 103.

[0031] Traveling wheels 105 are installed at the lower ends of the land-side support 102 and the sea-side support 103. The crane 100 can be moved horizontally by the traveling wheels 105 to match the entry position of the bulk carrier.

[0032] As shown in Figure 2, running rails 110 are installed on the running girder 101. The self-propelled trolley 106 moves along the running rails 110. As shown in Figure 1, a grab 107 is connected to the self-propelled trolley 106 via a wire 109. The self-propelled trolley 106 moves the grab 107 up and down, and opens and closes it by retracting or winding up the wire 109. The self-propelled trolley 106 loads the grab 107 into the bulk carrier with the grab 107 open, closes the grab 107, and then pulls it up to grasp the raw materials 108 inside the bulk carrier.

[0033] The self-propelled trolley 106 moves along the traveling girder 101 while maintaining its grip on the raw material 108, and opens the grab 107 above the hopper 111. As a result, the self-propelled trolley 106 feeds the raw material 108 into the belt conveyor 112 via the hopper 111.

[0034] Figure 3 is a schematic cross-sectional perspective view showing the structure of the traveling girder 101 in Figure 1. Figure 4 is a schematic enlarged cross-sectional view showing the appearance when a crack C occurs in the traveling girder 101 in Figure 1. The enlarged cross-sectional view shown in Figure 4 is, for example, an enlarged view of a part of the left end of the traveling girder 101 in the cross-sectional perspective view of Figure 3. Figure 5 is a schematic view of the crack C in Figure 4 as seen from the front of the inner web plate 101b.

[0035] The running girder 101 has a top plate 101a, an inner web plate 101b, an outer web plate 101c, and a bottom plate 101d. When the self-propelled trolley 106 runs on the running rail 110, the top plate 101a is subjected to the weight of the self-propelled trolley 106 as well as the weight of the grab 107 and raw materials 108. Therefore, triangular ribs 113 are attached to the top plate 101a as reinforcing members via welded joints 114. At this time, fatigue cracks C frequently occur at the tip of the welded joints 114 due to the load applied as the self-propelled trolley 106 repeatedly moves on the top plate 101a.

[0036] The inspection system 1 inspects the tip of the welded joint 114 where cracks C frequently occur, designating this tip as the target area P1, for cracks C. For example, the inspection system 1 determines whether or not cracks C are present at the target area P1.

[0037] Figure 6 is a schematic diagram showing an example of the configuration of the inspection system 1 installed on the traveling girder 101 shown in Figure 2. Figure 6 schematically shows a cross-section of the pair of traveling girders 101 shown in Figure 2. The inspection system 1 includes an inspection device 10, a heating device 20, and an imaging device 30.

[0038] The inspection device 10 includes any device for inspecting cracks C in a structure. In this disclosure, “structure” includes, for example, a crane 100 having a traveling girder 101. For example, the inspection device 10 includes general-purpose electronic devices such as a PC (Personal Computer), tablet PC, smartphone, and wearable devices such as a smartwatch. The inspection device 10 is communicatively connected to the imaging device 30 and acquires images generated in the imaging device 30 from the imaging device 30. The inspection device 10 is not limited to the above and may be one or more server devices that can communicate with each other, or other electronic devices dedicated to the inspection system 1. In this case, the inspection device 10 may be communicatively connected to the imaging device 30 by a communication unit 11 described later via a network including a mobile communication network and the internet.

[0039] Figure 7 is a block diagram showing an example of the configuration of the inspection device 10 shown in Figure 6. The inspection device 10 includes a communication unit 11, a storage unit 12, an input unit 13, an output unit 14, and a control unit 15.

[0040] The communication unit 11 includes one or more communication interfaces that are communicatively connected to the imaging device 30. These communication interfaces are either directly connected to the imaging device 30 or indirectly connected via a network or the like. The communication interfaces support, but are not limited to, communication standards based on wired connections with the imaging device 30 or short-range wireless communication standards. For example, the communication interfaces may support mobile communication standards such as 4G (4th Generation) and 5G (5th Generation), wired LAN (Local Area Network) standards, or wireless LAN standards. In one embodiment, the inspection device 10 is communicatively connected to the imaging device 30 via the communication unit 11.

[0041] The storage unit 12 includes storage modules such as an HDD (Hard Disk Drive), SSD (Solid State Drive), EEPROM (Electrically Erasable Programmable Read-Only Memory), ROM (Read-Only Memory), and RAM (Random Access Memory). The storage unit 12 stores information necessary to realize the operation of the inspection device 10. The storage unit 12 also stores information obtained through the operation of the inspection device 10. For example, the storage unit 12 stores system programs, application programs, and various data obtained by any means such as communication.

[0042] The storage unit 12 may function as a main memory module, an auxiliary memory module, or a cache memory. The storage unit 12 is not limited to one built into the inspection device 10, and may also include an external storage module connected by a digital input / output port such as USB (Universal Serial Bus).

[0043] The input unit 13 includes one or more input interfaces that detect user input and acquire input information based on user operations. These input interfaces include physical keys, capacitive keys, a touchscreen integrated with the display of the output unit 14, an imaging module such as a camera, and a microphone that accepts voice input.

[0044] The output unit 14 includes one or more output interfaces that output information to notify the user. These output interfaces include a display that outputs information as an image, a speaker that outputs information as sound, and a vibrator that outputs information as vibration. The display includes LCD (Liquid Crystal Display) and organic EL (Electro Luminescence) displays.

[0045] The control unit 15 includes one or more processors. In this disclosure, “processor” is a general-purpose processor or a dedicated processor specialized for a particular process, but is not limited to these. The control unit 15 includes, for example, a CPU (Central Processing Unit). The control unit 15 is communicatively connected to each component constituting the inspection device 10 and controls the operation of the entire inspection device 10.

[0046] As shown in Figure 6, the heating device 20 is installed inside the traveling girder 101, which includes the target area P1. The heating device 20 locally heats the area P1 to be inspected for crack C from inside the structure, for example, from inside the traveling girder 101. The heating device 20 directly heats the area around the target area P1 contained within the traveling girder 101.

[0047] The heating device 20 includes at least one of a lamp, a hot air source, a spray source, a laser light source, and a heater. The heating device 20 locally heats the area around the target part P1 located inside the traveling girder 101 from the back surface of the target part P1. The heating device 20 locally heats the vicinity of the area where crack C is expected to occur, such as the tip of the weld 114, by at least one of lamp heating, hot air heating, heating by spraying superheated steam and hot water, laser heating, and heating by direct contact with a heater. For example, the heating device 20 may include a dryer installed on the back surface of a part of the inner web plate 101b different from the target part P1.

[0048] The imaging device 30 is installed on the safety handrail 115 of the other traveling girder 101, which is located opposite the traveling girder 101 containing the target area P1. The imaging device 30 detects the infrared radiation energy generated from the surface of the target area P1 when the area around the target area P1 is locally heated by the heating device 20. The imaging device 30 remotely detects the infrared radiation energy generated from the surface of the target area P1 contained in one traveling girder 101 at the safety handrail 115 on the other traveling girder 101.

[0049] The imaging device 30 includes an infrared camera 31 and a telephoto lens 32 attached to the infrared camera 31 to increase the spatial resolution of the imaging device 30. The infrared camera 31 of the imaging device 30 is communicably connected to an inspection device 10, which functions, for example, as a measurement PC.

[0050] Figure 8 is a flowchart showing an example of an inspection method performed by the inspection system 1 in Figure 6. The flowchart shown in Figure 8 illustrates the process flow based on an inspection method for inspecting cracks C in a crane 100 having a traveling girder 101.

[0051] In step S101, the heating device 20 of the inspection system 1 locally heats the area P1 to be inspected for crack C from inside the traveling girder 101.

[0052] The heating device 20 heats the area around the tip of the weld 114 of the traveling girder 101, which is the target area P1, for a certain period of time. In this disclosure, "the area around the target area P1" includes, for example, any area where heat can be conducted to the crack C when heat diffuses from the heating point by the heating device 20 on the traveling girder 101. The area around the target area P1 includes, for example, the area within 40 mm below the tip of the weld 114, which is the target area P1. In addition, the heating time at one location by the heating device 20 is included in a time range of, for example, 5 seconds to 40 seconds in order to generate sufficient heat conduction on the inspection surface of the inner web plate 101b.

[0053] In step S101, the heating device 20 may move sequentially along the arrangement direction of the multiple welds 114 in order to thoroughly inspect the welds 114 that are formed over a wide area on the traveling girder 101.

[0054] In step S102, the inspection device 10 of the inspection system 1 acquires the temperature distribution at the target part P1 based on the infrared radiation energy generated from the surface of the target part P1 by the heating step in step S101. For example, the control unit 15 of the inspection device 10 acquires the temperature distribution at the target part P1 based on the infrared radiation energy generated from the surface of the target part P1 when the area around the target part P1 to be inspected for crack C is locally heated from inside the structure, for example, from inside the traveling girder 101.

[0055] For example, in step S102, the infrared camera 31 of the imaging device 30 measures the temperature distribution of the target area P1 on the inner web plate 101b and outputs a first image showing the temperature distribution to the inspection device 10, which acts as a measurement PC. The control unit 15 of the inspection device 10 acquires the first image showing the temperature distribution from the imaging device 30, which detects the infrared radiation energy generated from the surface of the target area P1 by the heating step in step S101. For example, the control unit 15 of the inspection device 10 acquires the temperature distribution based on the infrared radiation energy corresponding to the measurement wavelength of 1 μm to 20 μm.

[0056] In step S103, the inspection device 10 of the inspection system 1 determines the presence or absence of cracks C at the target part P1 based on the temperature distribution acquired in the acquisition step of step S102. For example, the control unit 15 of the inspection device 10 determines the presence or absence of cracks C at the target part P1 based on the temperature distribution acquired in the acquisition step of step S102.

[0057] The control unit 15 of the inspection device 10 determines the presence or absence of cracks C at the target area P1 based on a first image showing the temperature distribution output in step S102 from the imaging device 30 that detects infrared radiation energy. For example, the control unit 15 of the inspection device 10 may determine the presence or absence of cracks C based on the pattern of the temperature profile on the line in the first image acquired in step S102. For example, the control unit 15 of the inspection device 10 may determine the presence or absence of cracks C based on a second image showing the temperature gradient distribution calculated by performing differential processing on the first image acquired in step S102.

[0058] Figure 9 is a schematic diagram showing a first example of the first image acquired in step S102 of Figure 8. In the first image shown in Figure 9, the horizontal axis corresponds to the x-direction position shown in Figure 5. The vertical axis corresponds to the y-direction position shown in Figure 5. The first image indicates that the whiter the color, the higher the temperature at the corresponding location on the surface of the inner web plate 101b, and the darker the color, the lower the temperature at the corresponding location on the surface of the inner web plate 101b. The first image shows how heat is conducted concentrically from the local heating point P2 by the heating device 20.

[0059] In the first image shown in Figure 9, a crack C is observed at the target area P1 located at the tip of the weld 114 formed around the triangular rib 113. The first image shown in Figure 9 is a temperature distribution image when a crack C is present at the tip of the weld 114.

[0060] Figure 10 is a schematic diagram showing a second example of the first image acquired in step S102 of Figure 8. The first image shown in Figure 10 corresponds to the first image shown in Figure 9. In the first image shown in Figure 10, the process of heat conduction in a concentric manner from the local heating point P2 by the heating device 20 is also shown.

[0061] In the first image shown in Figure 10, no crack C is observed at the target area P1 located at the tip of the weld 114 formed around the triangular rib 113. The first image shown in Figure 10 is a temperature distribution image when no crack C is present at the tip of the weld 114.

[0062] Figure 11 is a graph showing the temperature line profile of the first image acquired in step S102 of Figure 8. The temperature line profile in Figure 11, shown by the solid line, for the case with crack C, shows the dependence of the temperature rise ΔT for each position in the y-direction of Figure 5 along line L1 shown in Figure 9. The temperature line profile in Figure 11, shown by the dashed line, for the case of a sound area without crack C, shows the dependence of the temperature rise ΔT for each position in the y-direction of Figure 5 along line L2 shown in Figure 10.

[0063] Figure 11 shows a comparison of the temperature line profiles with and without the presence of crack C. When crack C is absent at the target area P1 located at the tip of the weld 114, the temperature line profile gradually decreases concentrically due to heat conduction as it moves toward the triangular rib 113 in the y-direction, centered on the heating point P2. In the graph shown in Figure 11, the local peaks correspond to the tip positions of the triangular rib 113.

[0064] If a crack C exists at the target area P1 located at the tip of the welded joint 114, the opening of the crack C obstructs the conduction of heat from the heating point P2. Therefore, a sharp temperature difference occurs before and after the crack C present at the target area P1. The temperature line profile shows a sharp slope at the location where the crack C exists. The control unit 15 of the inspection device 10 determines the presence or absence of the crack C by measuring this temperature difference using the infrared camera 31. That is, the control unit 15 of the inspection device 10 determines the presence or absence of the crack C based on the pattern of the temperature profile on the line in the first image.

[0065] Figure 12 is a schematic diagram showing an example of a second image acquired in step S103 of Figure 8. The second image shown in Figure 12 corresponds to the first image shown in Figure 9.

[0066] For example, the control unit 15 of the inspection device 10 may determine the presence or absence of a crack C based on the second image in Figure 12, which shows the temperature gradient distribution calculated by performing differential processing on the first image in Figure 9. The control unit 15 of the inspection device 10 generates the second image in Figure 12 as a temperature gradient distribution image by applying a differential filter in the x and y directions to the first image in Figure 9, which is a temperature distribution image of the crack C portion. As shown in Figure 12, applying a differential filter to the temperature distribution image enhances the edges and improves the signal-to-noise ratio. Therefore, the crack C is more clearly shown in the image. The control unit 15 of the inspection device 10 can easily detect the crack C shown in the second image based on arbitrary image analysis or the like.

[0067] The following primarily describes the effects of the inspection device 10 according to one embodiment of this disclosure. The effects described below also apply to the inspection system 1 according to one embodiment of this disclosure.

[0068] According to the inspection device 10 of the above embodiment, the presence or absence of cracks C can be inspected more efficiently and accurately. The inspection device 10 acquires the temperature distribution at the target area P1 based on the infrared radiation energy generated from the surface of the target area P1 when the area around the target area P1 to be inspected is locally heated from inside the traveling girder 101, and determines the presence or absence of cracks C based on the acquired temperature distribution. When the area around the target area P1 is locally heated, a large temperature difference is created before and after the crack C. Such a temperature difference continues for a relatively long period of time. Therefore, measurement can be easily performed even if an inexpensive and compact uncooled infrared thermography is used as the imaging device 30.

[0069] In addition, the heating device 20 can heat any location while the equipment is stopped, allowing the inspection device 10 to determine the presence or absence of cracks C. Therefore, the inspection device 10 can also inspect all parts of the crane 100 as target parts P1. Furthermore, the direct heating method using the heating device 20 makes heating easy. In addition, the inspection system 1 can be easily moved after heating. Therefore, the inspection efficiency is very high.

[0070] In addition, the inspection device 10 can observe the heating state using infrared thermography with an imaging device 30 equipped with an infrared camera 31. Therefore, the risk of overlooking cracks C due to poor propagation of ultrasonic vibrations is also reduced. Since the inspection device 10 inspects cracks C by utilizing heat conduction beneath the coating, it is possible to inspect cracks C even when a coating is present. The inspection device 10 can accurately inspect even small fatigue cracks C that do not affect the surface condition, as a localized delay in heat conduction occurs even in such small cracks C.

[0071] It will be apparent to those skilled in the art that this disclosure can be implemented in other predetermined forms besides the embodiments described above without deviating from its spirit or essential features. Therefore, the prior description is illustrative and not limiting. The scope of the disclosure is defined not by the prior description but by the added claims. Any modifications within their equivalent scope are included therein.

[0072] For example, the shape, pattern, size, arrangement, orientation, type, and number of each component described above are not limited to those shown in the above description and drawings. The shape, pattern, size, arrangement, orientation, type, and number of each component may be configured arbitrarily as long as they can realize their function. The components of the illustrated inspection device 10 and inspection system 1 are functional concepts, and the specific form of each component is not limited to those shown.

[0073] For example, the functions included in each configuration or step can be rearranged or omitted in a way that does not create logical inconsistencies, and multiple configurations or steps can be combined into one or divided into two.

[0074] For example, it is also possible to configure a general-purpose electronic device such as a smartphone or computer to function as the inspection device 10 according to the above-described embodiment. Specifically, a program describing the processing content that realizes each function of the inspection device 10 according to the embodiment is stored in the memory of the electronic device, and the processor of the electronic device reads and executes the program. Therefore, this disclosure can also be realized as a program that can be executed by a processor.

[0075] Alternatively, the disclosure may also be implemented as a non-temporary computer-readable medium storing a program executable by one or more processors for causing an inspection device 10 or the like to perform each function according to one embodiment. These are also to be understood as being included within the scope of the disclosure.

[0076] For example, at least some of the processing operations performed in the inspection device 10 in the above-described embodiment may be performed in the imaging device 30. For example, instead of the inspection device 10, the imaging device 30 itself may perform the series of processing operations related to the inspection device 10 described above. At least some of the processing operations performed in the imaging device 30 may be performed in the inspection device 10.

[0077] In the above embodiment, the area around the target part P1 was described as including the region within 40 mm below the tip of the welded part 114 that becomes the target part P1, but it is not limited to this. The area around the target part P1 may include the region beyond 40 mm below the tip of the welded part 114 that becomes the target part P1. The area around the target part P1 is not limited to the side extending downward from the welded part 114. For example, the area around the target part P1 may include any region where the direction of heat propagation conducted from the heating point P2 and the direction of crack C extension intersect each other. For example, if the crack C does not occur at the tip of the welded part 114, as shown in Figure 5, but rather along the vertical direction at the lateral end of the welded part 114, the area around the target part P1 may include the region within 40 mm outward in the left-right direction from the lateral end of the welded part 114 that becomes the target part P1.

[0078] In the above embodiment, the target part P1 was described as being located at the tip of the welded portion 114 formed around the triangular rib 113 in the traveling girder 101, but it is not limited to this. The target part P1 may include any other part of the traveling girder 101, or any other part of the crane 100 other than the traveling girder 101.

[0079] Figure 13 is a schematic diagram showing an example of the configuration of inspection system 1 according to a modified example of the present disclosure. Figure 13 corresponds to Figure 6.

[0080] In the above embodiment, the heating device 20 was described as including a dryer installed on the back surface of the inner web plate 101b at a location different from the target area P1, but is not limited thereto. The heating device 20 may also include a rubber heater installed on the back surface of the inner web plate 101b at a location different from the target area P1. For example, the rubber heater may be installed at a position within 40 mm below the tip of the weld 114 that constitutes the target area P1. The rubber heater may be permanently installed or may be attached each time a crack C is inspected.

[0081] In the above embodiment, the structure was described as including a crane 100 having a traveling girder 101, but is not limited thereto. The structure may include any other object in which cracks C may occur and which may be subject to inspection by the inspection device 10. [Explanation of Symbols]

[0082] 1. Inspection System 10 Inspection equipment 11 Communications Department 12 Storage section 13 Input section 14 Output section 15 Control Unit 20 Heating device 21 Light 22 Concave mirror 30 Imaging device 31 Infrared Camera 32 Telephoto lens 100 Cranes 101 Traveling girder 101a Top plate 101b Inner web plate 101c Outer web plate 101d bottom plate 102 Land side support 103 Sea side support 104 Tension Bar 105 Running wheels 106 Self-propelled trolley 107 Glove 108 Raw materials 109 wire 110 Running Rails 111 Hoppa 112 Belt conveyor 113 Triangular Ribs 114 Welded section 115 Safety Handrail C Crack L1 Line L2 Line P1 Target area P2 heating point

Claims

1. An inspection device for inspecting cracks in structures, A heating device that locally heats the area around the target part to be inspected for the crack from inside the structure, An imaging device that detects infrared radiation energy, Equipped with, It is an inspection system, The inspection device includes a control unit, The control unit acquires the temperature distribution at the target area from the imaging device based on the infrared radiation energy generated from the surface of the target area due to heating by the heating device, and determines the presence or absence of cracks based on the acquired temperature distribution. The heating device is located on the back side of the target part, inside the structure, The imaging device is located on the surface side of the target part, outside the structure, Inspection system.

2. The inspection system according to claim 1, The control unit determines the presence or absence of the crack based on the first image showing the temperature distribution output from the imaging device. Inspection system.

3. The inspection system according to claim 2, The control unit determines the presence or absence of the crack based on the pattern of the temperature profile on the line in the first image. Inspection system.

4. An inspection system according to claim 2 or 3, The control unit determines the presence or absence of the crack based on a second image showing the temperature gradient distribution calculated by performing differential processing on the first image. Inspection system.

5. An inspection system according to any one of claims 1 to 3, The control unit acquires the temperature distribution based on the infrared radiation energy corresponding to the measurement wavelength of 1 μm to 20 μm. Inspection system.

6. An inspection system according to any one of claims 1 to 3, The aforementioned structure includes a crane having a traveling girder, The control unit acquires the temperature distribution from the imaging device based on the infrared radiation energy generated from the surface of the target area when the area around the target area is locally heated from inside the traveling girder by the heating device. Inspection system.

7. An inspection system according to any one of claims 1 to 3, The heating device comprises at least one of a lamp, a hot air source, a spray source, a laser light source, and a heater. Inspection system.

8. A method for inspecting cracks in structures, A heating step involves locally heating the area around the target part to be inspected for the crack from inside the structure using a heating device, A detection step in which infrared radiation energy generated from the surface of the target part by the heating step is detected by an imaging device, An acquisition step of acquiring the temperature distribution at the target area from the imaging device based on the infrared radiation energy, A determination step in which the presence or absence of the crack is determined based on the temperature distribution obtained in the acquisition step, Includes, The heating device is located on the back side of the target part, inside the structure, The imaging device is located on the surface side of the target part, outside the structure, Testing method.

Images