Abnormality detection method, abnormality detection device, and tunnel boring machine

Abstract

To detect any abnormality such as uneven wear, ring cracking, or chipping occurring on the outer periphery of a disc cutter while the tunnel excavator 1 is stationary.SOLUTION: An abnormality detection device 60 for measuring wear of a disc cutter of a stationary tunnel excavator comprises an ultrasonic sensor 61 that contacts a cutter top of the disc cutter and emits surface waves along the circumferential direction of the cutter top, a signal receiving unit 112 that receives a signal transmitted from the ultrasonic sensor 61, and a display control unit 113 that controls a monitor 62 to display the signal received by the signal receiving unit 112.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an abnormality detection method, an abnormality detection device, and a tunnel boring machine. [Background technology]

[0002] A technique is known in which an ultrasonic sensor is used to detect the distance to the cutting edge of a disc cutter mounted on the cutter head of a tunnel boring machine, based on the time it takes for the ultrasonic sensor to receive a reflected wave of the ultrasonic wave emitted from the radial direction behind the disc cutter in a non-contact manner toward the cutting edge of the disc cutter (see, for example, Patent Document 1). The technique described in Patent Document 1 detects the wear state of the disc cutter from the detected distance to the cutting edge of the disc cutter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-082986 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique described in Patent Document 1 cannot detect wear on the front side of the disc cutter when measuring the amount of wear on the disc cutter while the tunnel boring machine 1 is stationary.

[0005] The present invention aims to detect any abnormality, such as uneven wear, ring cracking, or chipping, that occurs on the outer periphery of the disc cutter while the tunnel boring machine 1 is stationary. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an abnormality detection method for detecting an abnormality in the disc cutter of a stationary tunnel boring machine, which comprises bringing an ultrasonic sensor into contact with the cutter top of the disc cutter, emitting a surface wave along the circumferential direction of the cutter top, receiving a signal emitted from and returned to the ultrasonic sensor, and detecting an abnormality that has occurred on the outer periphery of the disc cutter from the received signal.

[0007] According to one aspect of the present invention, there is provided an abnormality detection device for measuring wear on the disc cutter of a stationary tunnel boring machine, comprising: an ultrasonic sensor that contacts the cutter top of the disc cutter and emits surface waves circumferentially around the cutter top; a signal receiving unit that receives the signal emitted from the ultrasonic sensor and returned to the ultrasonic sensor; and an abnormality detection unit that detects any of the abnormalities, such as uneven wear, ring cracks, and chips, that have occurred on the outer periphery of the disc cutter, based on the signal received by the signal receiving unit.

[0008] According to one aspect of the present invention, there is provided an abnormality detection device for measuring wear on the disc cutter of a stationary tunnel boring machine, comprising an ultrasonic sensor that contacts the cutter top of the disc cutter and emits surface waves along the circumferential direction of the cutter top, a signal receiving unit that receives the signal emitted from the ultrasonic sensor and returned to the ultrasonic sensor, and a calculation unit that calculates the circumferential length of the outer periphery of the disc cutter based on the signal received by the signal receiving unit.

[0009] According to one aspect of the present invention, there is provided a tunnel boring machine in which the wear of a disc cutter is measured while the machine is stationary, comprising: a main body; a cutter head installed on the front side of the main body and for excavating rock; a disc cutter installed in front of the cutter head and rotatably supported relative to the cutter head; an ultrasonic sensor that contacts the cutter top of the disc cutter and emits surface waves along the circumferential direction of the cutter top; a signal receiving unit that receives signals emitted from the ultrasonic sensor and returned to the ultrasonic sensor; and an abnormality detection unit that detects abnormalities that have occurred on the outer periphery of the disc cutter based on the signals received by the signal receiving unit.

[0010] According to one aspect of the present invention, there is provided a tunnel boring machine in which the wear of a disc cutter is measured while the machine is stationary, comprising: a main body; a cutter head installed on the front side of the main body and for excavating rock; a disc cutter installed in front of the cutter head and rotatably supported relative to the cutter head; an ultrasonic sensor that contacts the cutter top of the disc cutter and emits surface waves along the circumferential direction of the cutter top; a signal receiving unit that receives a signal emitted from the ultrasonic sensor and returned to the ultrasonic sensor; and a calculation unit that calculates the circumference of the outer periphery of the disc cutter based on the signal received by the signal receiving unit. [Effects of the Invention]

[0011] According to the present invention, any of the abnormalities such as uneven wear, ring cracks and chips occurring on the outer periphery of the disc cutter can be detected while the tunnel boring machine 1 is stationary. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a side view showing the configuration of a tunnel boring machine according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing an outline of a cutter head of a tunnel boring machine according to an embodiment. [Figure 3] FIG. 3 is a side view showing the state in which the disc cutter is attached to the case. [Figure 4] FIG. 4 is a side view showing the cutting of a disc cutter in which only a portion of the circumference of the disc cutter is worn. [Figure 5] FIG. 5 is a front view showing the cutting of a disc cutter in which only a portion of the circumference of the disc cutter is worn. [Figure 6] FIG. 6 is a block diagram showing the configuration of the drive controller. [Figure 7] FIG. 7 is a schematic diagram illustrating a modified example of the abnormality detection device. [Figure 8] FIG. 8 is a side view of FIG. [Figure 9] FIG. 9 is a block diagram showing the configuration of the measurement controller. [Figure 10] FIG. 10 is a schematic diagram illustrating an example of a measured waveform. [Figure 11] FIG. 11 is a schematic diagram illustrating another example of the measured waveform. [Figure 12] FIG. 12 is a block diagram illustrating a computer system according to an embodiment. [Figure 13] FIG. 13 is a flowchart showing an example of a processing procedure of the measurement method. [Figure 14] FIG. 14 is a schematic diagram illustrating a state in which an abnormality detection device measures a disk cutter using another abnormality detection method. [Figure 15] FIG. 15 is a schematic diagram illustrating an example of a measured waveform. [Figure 16] FIG. 16 is a flowchart showing an example of a processing procedure of another abnormality detection method. [Figure 17] FIG. 17 is a schematic diagram illustrating an example of a state in which the abnormality detection device measures the disk cutter. [Figure 18] FIG. 18 is a schematic diagram illustrating a modified example of the abnormality detection device. [Figure 19] FIG. 19 is a block diagram showing the configuration of the measurement controller. [Figure 20] FIG. 20 is a block diagram showing the configuration of the measurement controller. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto. The components of each embodiment described below can be combined as appropriate. In addition, some components may not be used.

[0014] (Embodiment) [Tunnel boring machine] FIG. 1 is a side view showing the configuration of a tunnel boring machine 1 according to an embodiment. FIG. 2 is a perspective view showing an outline of a cutter head 30 of the tunnel boring machine 1 according to an embodiment. The tunnel boring machine 1 excavates bedrock, for example, in the construction of underground structures such as tunnels and waterworks. The tunnel boring machine 1 comprises a main body 10 and a cutter head 30 that is installed in front of the main body 10 and excavates the bedrock. As shown in FIGS. 1 and 2, the cutter head 30 has a dome-like shape, and a cutter chamber 30C is formed inside the cutter head 30, which is a space that takes in excavation waste generated by excavation.

[0015] The main body 10 has a main beam 14 extending in the front-to-rear direction and a cutter head support 22 provided at the front end of the main beam 14. The cutter head 30 is rotatably connected to the cutter head support 22 via a bearing 23. The cutter head support 22 of the main body 10 has a roof support 11 installed on its upper part, side supports 12 installed on its sides, and vertical supports 13 installed on its lower part. As shown in Figure 2, the roof support 11, side supports 12, and vertical supports 13 are installed in a cylindrical shape so that their outer peripheries follow the shape of the excavation cross section.

[0016] Inside the main body 10, there are installed a gripper 15 that is pressed against the tunnel wall, and a thrust jack 16 that is extendable and contractable along the main beam 14. The thrust jack 16 has its front axial end attached to the front side of the main beam 14 and its rear end attached to the gripper 15. The thrust jack 16 is installed so that it can extend and contract in the front-to-rear direction. The tunnel boring machine 1 generates a thrust force by the extension and contraction of the thrust jack 16. The tunnel boring machine 1 obtains a thrust reaction force by pressing the gripper 15 against the tunnel wall.

[0017] The main body 10 contains a belt conveyor 20 extending in the front-rear direction, a hopper chute 21 installed on the upper front side of the belt conveyor 20, a cutter head support 22 installed at the front end of the main beam 14, and a drive motor 29. The belt conveyor 20 transports excavation debris generated during excavation to the rear. The belt conveyor 20 is installed inside the cylindrical main beam 14, and its tip extends through the cutter head support 22 into the cutter chamber 30C. The hopper chute 21 opens into the cutter chamber 30C and guides the excavation debris scooped up by the bucket 39 of the cutter head 30 to the belt conveyor 20. The cutter head support 22 supports the cutter head 30 rotatably around its rotation axis AX1. A drive motor 29 for rotating the cutter head 30 is installed on the cutter head support 22. The drive motor 29 is a hydraulic motor or an electric motor.

[0018] A drive motor 29 is installed on the cutter head support 22 to which the cutter head 30 is connected via a bearing 23. The cutter head 30 is rotated about a rotation axis AX1 by the drive motor 29. The cutter head 30 moves in the front-to-rear direction relative to the gripper 15 as the thrust jack 16 extends and retracts. A plurality of disc cutters 40 are attached to the cutter head 30. The cutter head 30 is installed in front of the main body 10. A plurality of cylindrical cases 32 that house and hold the disc cutters 40 are installed on the cutter head 30. That is, the cases 32 are installed on the cutter head 30 in accordance with the positions of the disc cutters 40 to be installed on the cutter head 30.

[0019] [Disc cutter] The disc cutter 40 will be described using Figures 3 to 5. Figure 3 is a side view of the disc cutter 40. Figure 4 is a side view showing a disc cutter cutting edge in which only a portion of the circumference is worn. Figure 5 is a front view showing a disc cutter cutting edge in which only a portion of the circumference is worn. The disc cutter 40 shown in Figures 4 and 5 shows a state in which the cutter tip 44, which is the cutting edge of the cutter cutting edge 41, is unevenly worn. The disc cutter 40 is rotatably supported by the cutter head 30. The disc cutter 40 is installed on the cutter head 30 so that its rotation axis (fixed axis AX2, described later) intersects with the rotation axis AX1 of the cutter head 30. The disc cutter 40 rotates while being pressed against the excavation face of the tunnel, thereby crushing the rock mass. More specifically, with the cutter head 30 rotating about the AX1 axis, a forward thrust is applied to the main body 10 and the cutter head 30, causing the disc cutter 40 to rotate about the AX2 axis while pressed against the rock. As the disc cutter 40 rotates while pressed against the rock, the rock is crushed and cracks are generated in the rock at the contact point between the cutter tip 44 of the disc cutter 40 and the rock. The cracks generated in the rock connect with other adjacent cracks, causing adjacent fractures and excavating the rock. The excavation waste generated during the excavation of the rock is scooped into the hopper chute 21 opening into the cutter chamber 30C by the bucket 39 installed on the cutter head 30 and transported rearward by the belt conveyor 20.

[0020] The disc cutter 40 includes a cutting ring 41, a hub 42 that supports the cutting ring 41 so that it cannot rotate, a shaft (not shown) that rotatably supports the hub 42 via bearings (not shown), and a pair of retainers 43 that are positioned to sandwich the hub 42 from both sides in the axial direction and hold the shaft. The center line of the shaft held by the pair of retainers 43 is shown as a fixed axis AX2 in FIG. 3. That is, the cutting ring 41 and the hub 42 are rotatably supported on the fixed axis AX2 via bearings (not shown). The cutting ring 41 and the hub 42 can rotate together. The pair of retainers 43 are holding parts that rotatably hold the cutting ring by sandwiching it in the axial direction. The cutting ring 41 excavates the excavation surface by rotating while being pressed against the excavation surface of the tunnel.

[0021] The cutter ring 41 has a cutter top 44. The cutter top 44 protrudes forward and rearward from the case 32. The cutter top 44 is exposed at the front and rear surfaces of the case 32. The cutter top 44 protrudes forward from the front surface 31 of the cutter head 30.

[0022] The cutter ring 41 may experience uneven wear at the cutter top 44 due to, for example, excavating hard rock or due to aging. When the cutter top 44 experiences uneven wear, an uneven wear portion 44A is formed where part of the arc on the outer periphery of the cutter top 44 becomes a chord.

[0023] The cutter ring 41 may suffer from ring cracks or ring chipping. Ring cracks simply refer to a state in which a crack has occurred in the cutter tip 44. Ring chipping not only refers to a crack, but also to a state in which a part of the cutter tip 44 has chipped off and been lost.

[0024] [Tunnel boring machine control system] The drive controller 100 will be described using Figure 6. Figure 6 is a block diagram showing the configuration of the drive controller 100. The tunnel boring machine 1 is controlled, for example, by the drive controller 100. The drive controller 100 operates the tunnel boring machine 1 based on, for example, operation information input via an operation panel (not shown) or the like, or operation information input via an excavation management system (not shown). The drive controller 100 controls the rotation and stopping of the drive motor 29 by means of a drive motor control unit 101.

[0025] [Anomaly detection device] An abnormality detection device 60 for measuring the amount of wear of the cutter ring 41 of the disc cutter 40, which is provided in the tunnel boring machine 1, will be described using Figures 7 to 9. Figure 7 is a schematic diagram illustrating a modified example of the abnormality detection device. Figure 8 is a side view of Figure 7. Figure 9 is a block diagram showing the configuration of the measurement controller. The abnormality detection device 60 includes an ultrasonic sensor 61, a monitor 62 which is a display unit, and a measurement controller 110. The ultrasonic sensor 61 and the monitor 62 can communicate data with the measurement controller 110 via wire or wirelessly.

[0026] The ultrasonic sensor 61 is an ultrasonic sensor that emits surface waves. As shown in FIGS. 7 and 8, the ultrasonic sensor 61 includes an oscillator 611 and an acrylic material 612, which is an example of a material that transmits ultrasonic waves. The oscillator 611 emits ultrasonic waves. The oscillator 611 is made up of a piezoelectric element. When a voltage is applied to the piezoelectric element, the piezoelectric element vibrates and generates ultrasonic waves.

[0027] The oscillator 611 also functions as a receiving unit that receives reflected waves. More specifically, the oscillator 611 generates a voltage when vibrations such as reflected waves are applied to the piezoelectric element from the outside. The generated voltage is detected by the measurement controller 110, and a waveform such as that shown in FIG. 10 is displayed.

[0028] The oscillator 611 is disposed on an acrylic material 612. The acrylic material 612 is formed of, for example, a transparent acrylic resin that transmits ultrasonic waves. The acrylic material 612 is just an example, and any material that transmits ultrasonic waves may be used, and is not limited to an acrylic material.

[0029] The acrylic material 612 shown in Figures 7 and 8 is formed in a wedge shape with a wedge portion 612A provided on its outer circumferential surface. The cutter tip 44 of the disc cutter 40 can enter the wedge portion 612A. With the wedge portion 612A of the acrylic material 612 in contact with the surface of the cutter tip 44 of the disc cutter 40, the ultrasonic sensor 61 emits a surface wave from the oscillator 611 along the circumferential direction A of the cutter tip 44 in Figure 5. Note that the wedge portion 612A is not an essential component, and the acrylic material 612 may have a shape in which each surface is flat.

[0030] The ultrasonic sensor 61 emits a surface wave from the oscillator 611 along the circumferential direction A of the cutter top 44 in FIG. 5, with the acrylic material 612 in contact with the surface of the cutter top 44 of the disc cutter 40.

[0031] Surface waves are a type of ultrasonic wave that propagates along the surface of an object. When ultrasonic waves are generated with acrylic material 612 in contact with the object to be measured so that oscillator 611 is oriented at an angle, the ultrasonic waves from oscillator 611 become surface waves that propagate along the surface of the object due to refraction. As a result, the ultrasonic waves emitted from oscillator 611 become surface waves due to refraction as they propagate to the surface of cutter top 44 of disc cutter 40, and oscillator 611 receives the resulting circulating waves and reflected waves, which then produce voltage signals.

[0032] The ultrasonic sensor 61 emits a surface wave based on a control signal from the ultrasonic sensor control unit 111 (see FIG. 9) of the measurement controller 110. The ultrasonic sensor 61 receives a signal that is the emitted surface wave returning to the ultrasonic sensor, and outputs a signal that indicates the circumferential shape of the surface of the cutter top 44 to the signal receiving unit 112 (see FIG. 9) of the measurement controller 110. Examples of signals that return to the ultrasonic sensor include circumferential waves and reflected waves, which will be described later.

[0033] The monitor 62 includes a display such as a liquid crystal display (LCD) or an organic electroluminescence display (OLED). The monitor 62 may be separate from the measurement controller 110, or may be located inside the measurement controller 110. The monitor 62 displays an image based on a video signal from a display control unit 113 (see FIG. 9) of the measurement controller 110. The monitor 62 displays, as waveforms, circulating waves that are generated when ultrasonic waves emitted from the oscillator 611 of the ultrasonic sensor 61 make a full circle and are transmitted to the oscillator 611, as well as reflected waves that are transmitted to the oscillator 611 due to abnormalities such as uneven wear, cracks, and chips, which will be described later.

[0034] Uneven wear may occur on the cutter ring 41 during excavation. Normally, the cutter ring 41 is worn evenly as it excavates the ground while rotating, but once uneven wear occurs, the cutter ring 41 is constrained by the excavation surface at the location of the uneven wear, making it impossible for the cutter ring 41 to rotate from that point. If excavation continues in this state, the uneven wear will increase, leading to more serious problems such as damage to the cutter ring 41 or even to the rotating shaft of the cutter ring 41, so it is desirable to detect uneven wear early.

[0035] Referring to FIG. 10, a measurement waveform of a cutter tip 44 that is free of irregular wear, cracks, chips, or other abnormalities will be described. FIG. 10 is a schematic diagram illustrating an example of a measurement waveform. FIG. 10 shows a measurement waveform of a cutter tip 44 that is brand new or has uniform wear around its entire circumference and is free of irregular wear, ring cracks, chips, or other abnormalities. The measurement waveform 200 only shows a first waveform P11, which is a circulating wave generated by the oscillator 611 and detected by the oscillator 611 after circulating around the cutter tip 44. In the example shown in FIG. 10, since the cutter ring 41 is free of irregular wear or other abnormalities, no reflected wave is detected, and only the circulating wave is detected. The surface wave path length at the peak value of the first waveform P11 is the outer circumferential length of the cutter tip 44. The first waveform P11 appears within the expected range Q of the measurement waveform 200.

[0036] The first waveform is a waveform having the highest peak value among waveforms having peak values ​​above a predetermined threshold detected in the measured waveform. In the embodiment, the first waveform is assumed to be a circulating wave.

[0037] The path distance can identify the location of an abnormality based on the time it takes for the reflected wave or circulating wave to return using the surface wave from the ultrasonic sensor 61. The path distance in Fig. 10 is the distance traveled by the surface wave from when it is emitted from the oscillator 611 until the reflected wave or circulating wave returns.

[0038] The expected range Q is the range of the expected circumferential length that should be present at present. The expected range Q is a range including both the front and rear of the circumferential length of the cutter top 44 where no wear, including uneven wear, has occurred. The range including both the front and rear of the circumferential length of the cutter top 44 is a range that allows for a range in which the circumferential length has become shorter due to wear that is not abnormal to excavation. If normal wear that is not abnormal has occurred, the path distance at which the first waveform rises will be shorter than the path distance of the first waveform before wear occurred. The range including both the front and rear of the circumferential length of the cutter top 44 is a range that allows for measurement error.

[0039] When uneven wear occurs on the cutter tip 44 of the cutter ring 41, the arc of the outer periphery of the cutter tip 44 becomes a chord, and the surface wave path distance on the outer periphery of the cutter tip 44 becomes shorter. As a result, the peak value of the first waveform P11 that appears in the measured waveform 200 when uneven wear occurs has a shorter path distance than when uneven wear does not occur. The wear height of the uneven wear portion 44A is calculated from the difference between the theoretical path distance when it is assumed that uneven wear does not occur and the path distance on the outer periphery of the cutter tip 44.

[0040] When uneven wear occurs on the cutter tip 44 of the cutter ring 41, reflected waves are generated at the inflection points at both circumferential ends of the unevenly worn portion 44A of the cutter tip 44. As a result, when uneven wear occurs, a waveform other than the first waveform P11 appears in the measured waveform 200. If the path length of the first waveform P11 is simply shortened, it is determined that the cutter ring 41 is normally worn, but it is possible to determine that uneven wear has occurred using the following method.

[0041] Referring to FIG. 11, the measured waveform of the cutter tip 44 where uneven wear has occurred will be described. FIG. 11 is a schematic diagram illustrating another example of the measured waveform. FIG. 11 shows the measured waveform of the cutter tip 44 where uneven wear has occurred. In the measured waveform 201, a first waveform P11 appears within the expected range. For cutters 41 with the same outer diameter when a location other than the uneven wear is used as a reference, the peak value of the first waveform P11 in FIG. 11 has a shorter path length than the peak value of the first waveform P11 in FIG. 10. In addition to the first waveform P11, the measured waveform 201 also shows second waveforms P12 and P13 as reflected waves from corners 44B and 44C, which are inflection points at both ends of the uneven wear portion 44A in the circumferential direction. In the example shown in FIG. 11, the measured waveform 201 shows the second waveforms P12 and P13 outside the expected range. The second waveform P12 is a waveform corresponding to the corner 44B of the uneven wear portion 44A of the cutter top 44 shown in Fig. 5. The second waveform P13 is a waveform corresponding to the corner 44C of the uneven wear portion 44A of the cutter top 44 shown in Fig. 5. The corner 44B corresponding to the second waveform P12 is located more than 180 degrees before the contact position of the ultrasonic sensor 61, and therefore is detected at a path distance earlier than the first waveform P11. The corner 44C corresponding to the second waveform P13 is located more than 180 degrees behind the contact position of the ultrasonic sensor 61, and therefore is detected at a path distance further ahead than the first waveform P11.

[0042] The second waveform is a waveform in which the detected reception intensity in the measured waveform has a peak value exceeding a predetermined threshold and has a lower peak value than the first waveform. In the embodiment, the second waveform is assumed to be a waveform caused by an abnormality such as uneven wear, cracks, or chipping.

[0043] [Control system of abnormality detection device] 9, the ultrasonic sensor 61 and monitor 62 of the abnormality detection device 60 are controlled by a measurement controller 110. The measurement controller 110 includes an ultrasonic sensor control unit 111, a signal receiving unit 112, and a display control unit 113. The measurement controller 110 controls the transmission of surface waves from the ultrasonic sensor 61 using the ultrasonic sensor control unit 111. The measurement controller 110 receives ultrasonic waves, such as circulating waves and reflected waves, received by the oscillator 611 of the ultrasonic sensor 61 as voltage signals using the signal receiving unit 112. The measurement controller 110 controls the display control unit 113 to display the received signals on the monitor 62.

[0044] [Computer System] A computer system 1000 will be described using FIG. 12. FIG. 12 is a block diagram showing the computer system 1000 according to an embodiment. The drive controller 100 described above includes the computer system 1000. The computer system 1000 includes a processor 1001 such as a central processing unit (CPU), a main memory 1002 including a nonvolatile memory such as a read-only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 1003, and an interface 1004 including an input / output circuit. The functions of the drive controller 100 and the measurement controller 110 described above are stored as a program in the storage 1003. The processor 1001 reads the program from the storage 1003, loads it into the main memory 1002, and executes the above-described processing in accordance with the program. The program may be distributed to the computer system 1000 via a network.

[0045] [Method for measuring wear amount] Next, a method and process for measuring the amount of wear on the cutting ring 41 of the disc cutter 40 using the abnormality detection device 60 in a stationary tunnel boring machine 1 will be described. FIG. 13 is a flowchart showing an example of the processing procedure for the measurement method. For example, the amount of wear on the cutting ring 41 of the disc cutter 40 is measured before work begins each day or at predetermined intervals. In the embodiment, steps ST15 to ST21 will be described as being performed by a measurer.

[0046] First, the cutter head 30 is aligned (step ST11). The drive controller 100 controls the drive motor 29 by the drive motor control unit 101 to rotate the cutter head 30 so that the disk cutter 40 to be measured can be measured using the ultrasonic sensor 61. The drive controller 100 proceeds to step ST12.

[0047] It is determined whether the cutter head 30 has stopped (step ST12). The drive controller 100 determines whether the cutter head 30 has stopped based on whether the drive motor control unit 101 has stopped the drive motor 29. If the drive controller 100 determines that the cutter head 30 has stopped (Yes in step ST12), it proceeds to step ST13. If the drive controller 100 does not determine that the cutter head 30 has stopped (No in step ST12), it executes the processing of step ST12 again.

[0048] If it is determined that the cutter head 30 has stopped (Yes in step ST12), the measurer brings the ultrasonic sensor 61 into contact with the cutter tip 44 of the disc cutter 40 to be measured and performs measurement (step ST13). The measurer inputs a measurement start operation to an operation unit (not shown) of the measurement controller 110. Then, the measurement controller 110 causes the ultrasonic sensor control unit 111 to emit ultrasonic waves from the oscillator 611. Then, the measurement controller 110 causes the signal receiving unit 112 to refract the ultrasonic waves emitted from the oscillator 611 into surface waves that propagate to the surface of the cutter tip 44 of the disc cutter 40, and the oscillator 611 receives the resulting circulating waves and reflected waves, which then receive a voltage signal. The measurement controller 110 proceeds to step ST14.

[0049] Based on the voltage signal received by the signal receiving unit 112, a waveform is displayed on the monitor 62 (step ST14). The measurement controller 110 controls the display control unit 113 to display the measured waveform indicated by the signal received by the signal receiving unit 112 on the monitor 62. The measurement controller 110 proceeds to step ST15.

[0050] The measurer checks the measured waveform displayed on the monitor 62 and determines whether the waveform was measured normally (step ST15). For example, if the measured waveform displayed on the monitor 62 does not show a peak value corresponding to the circulating wave, or if the shape of the measured waveform clearly differs from the expected shape, such as when there is too much noise making it difficult to distinguish the first and second waveforms, the measurer determines that the waveform was not measured normally. If the measurer determines that the waveform was measured normally (Yes in step ST15), the process proceeds to step ST16. If the measurer does not determine that the waveform was measured normally (No in step ST15), the process proceeds to step ST18.

[0051] If it is determined that the displayed waveform was measured normally (Yes in step ST15), the measurer determines whether only the first waveform, which is a circulating wave that has made one revolution around the cutter top 44, was measured within the expected range (step ST16). The measurer checks the measured waveform displayed on the monitor 62 and determines whether only the first waveform is displayed within the expected range. If only the first waveform is displayed within the expected range, the measurer determines that only the first waveform was measured within the expected range. If it is determined that only the first waveform was measured within the expected range (Yes in step ST16), the measurer proceeds to step ST17. If it is not determined that only the first waveform was measured within the expected range (No in step ST16), the measurer proceeds to step ST19.

[0052] If it is determined that only the first waveform is measured within the expected range (Yes in step ST16), the measurer determines that no abnormality (uneven wear, cracks, chips, etc.) has occurred on the cutter top and that normal wear has occurred, and calculates the wear height (step ST17). The measurer calculates the wear height of the cutter ring 41 from the path distance at which the first waveform, which is thought to be a circulating wave, occurred. If the calculated wear height is equal to or less than a threshold, the measurer may determine it to be "normal." If the calculated wear height is greater than the threshold, the measurer may determine it to be "abnormal." The measurement controller 110 may display the wear height and the determination result on the monitor 62 via the display control unit 113. If the measurer confirms the determination result of "abnormal," the measurer interrupts the measurement. Then, the measurer, for example, replaces the disc cutter 40.

[0053] If the measurer does not determine that the waveform displayed on the monitor 62 was measured normally (No in step ST15), the measurer determines that there is a "measurement error" (step ST18). The measurement controller 110 may display the determination result of "measurement error" on the monitor 62 via the display control unit 113. When the measurer confirms the determination result of "measurement error", he or she discontinues the measurement. Then, the measurer checks, for example, the position and orientation of the ultrasonic sensor 61.

[0054] If it is not determined that only the first waveform has been measured within the expected range (No in step ST16), the measurer determines that there may be an abnormality (uneven wear, cracks, chipping, etc.) at the cutter top, and further determines whether multiple second waveforms have been measured (step ST19). The measurer checks the measured waveform displayed on the monitor 62 and determines whether multiple second waveforms are displayed. If it is determined that multiple second waveforms have been measured (Yes in step ST19), proceed to step ST21. If it is not determined that multiple second waveforms have been measured (No in step ST19), proceed to step ST20.

[0055] If the measurer does not determine that multiple second waveforms have been measured (No in step ST19), the measurer determines that "there is a possibility that the ring is cracked or chipped" (step ST20). The measurement controller 110 may cause the display control unit 113 to display the determination result of "there is a possibility that the ring is cracked or chipped" on the monitor 62. When the measurer confirms the determination result of "there is a possibility that the ring is cracked or chipped," the measurer suspends the measurement. Then, the measurer, for example, visually checks whether the disc cutter is cracked or chipped, and if cracks or chips are indeed present, replaces the disc cutter 40.

[0056] If it is determined that multiple second waveforms have been measured (Yes in step ST19), the measurer determines that "uneven wear is possible" (step ST21). The measurement controller 110 may cause the display control unit 113 to display the determination result of "uneven wear is possible" on the monitor 62. When the measurer confirms the determination result of "uneven wear is possible," the measurer suspends the measurement. Then, the measurer, for example, visually checks whether uneven wear has occurred on the disc cutter, and if uneven wear has indeed occurred, replaces the disc cutter 40.

[0057] This process is repeated to measure the amount of wear on the cutter tops 44 for all the disc cutters 40 to be measured.

[0058] [effect] In the embodiment, while the tunnel boring machine 1 is stationary, ultrasonic sensor 61 emits a surface wave toward cutter top 44 of disc cutter 40, and the measured waveform indicated by the received signal can be displayed on monitor 62. According to the embodiment, the amount of wear on disc cutter 40 can be measured from the measured waveform while the tunnel boring machine 1 is stationary. In the embodiment, by using the surface wave, the amount of wear on disc cutter 40 can be measured while the tunnel boring machine 1 is stationary, even if the front side of cutter top 44 of disc cutter 40 is worn.

[0059] In the embodiment, the ultrasonic sensor 61 is brought into contact with the cutter top 44 of the disc cutter 40 for measurement. According to the embodiment, the contact angle of the ultrasonic sensor 61 with respect to the cutter top 44 is stabilized and the contact area is enlarged, thereby increasing the input intensity and output intensity. According to the embodiment, the positional deviation of the ultrasonic sensor 61 with respect to the cutter top 44 is restricted, eliminating directional deviation with respect to the traveling direction of the surface wave and achieving stabilization.

[0060] [Method for improving detection accuracy of circulating wave position and abnormality detection (uneven wear, cracks, chipped positions, etc.)] A method for improving the detection accuracy of circulating wave positions and abnormality detection (positions of uneven wear, cracks, chipping, etc.) will be described with reference to Fig. 14 to Fig. 16. Fig. 14 is a schematic diagram illustrating a state in which an abnormality detection device measures a disk cutter using a method for improving the detection accuracy of abnormality detection. Fig. 15 is a schematic diagram illustrating an example of a measured waveform. Fig. 16 is a flowchart illustrating an example of a processing procedure for a method for improving the detection accuracy of abnormality detection.

[0061] 14, in this method for improving the detection accuracy of abnormality detection, a first contact position signal transmitted from the ultrasonic sensor 61 is received while the ultrasonic sensor 61 is in contact with a first contact position X1 on the cutter top 44, and a second contact position signal transmitted from the ultrasonic sensor 61 is received while the ultrasonic sensor 61 is in contact with a second contact position X2 different from the first contact position X1 on the cutter top 44. Then, based on a first measurement waveform 200 indicated by the first contact position signal and a second measurement waveform 200' indicated by the second contact position signal, the occurrence of an abnormality such as uneven wear is accurately confirmed and the position of the occurrence is accurately identified.

[0062] Referring to FIG. 15, a measurement waveform measured by the method for improving the detection accuracy of anomaly detection will be described. In the example shown in FIG. 15, the measurement waveform 200 indicated by the first contact position signal is indicated by a solid line, and the measurement waveform 200' indicated by the second contact position signal is indicated by a dashed line. FIG. 15 shows the first measurement waveform 200 and the second measurement waveform 200' of a cutter tip 44 that has experienced uneven wear. Even if the contact position of the ultrasonic sensor 61 on the cutter tip 44 is changed, the first waveform P11 and the first waveform P11', which are circumferential waves that have circulated around the cutter tip 44, appear at the same position. This is because the first waveform P11 and the first waveform P11' are obtained by simply changing the measurement position, not the circumferential distance of the cutter tip, i.e., the path distance. The average of the path distances of the peak values ​​of the first waveforms P11 and P11' in the two measurement waveforms 200 and 200' may be used as the path distance of the circumferential length of the cutter tip 44. Furthermore, when the contact position of the ultrasonic sensor 61 on the cutter top 44 is changed, the path length from the contact position to the inflection point changes for the reflected wave at the inflection point of the uneven wear portion 44A of the cutter top 44. The path lengths of the second waveforms P12' and P13' in the second measured waveform 200', which correspond to the reflected waves generated at the inflection points 44B and 44C, respectively, are different from the path lengths of the second waveforms P12 and P13 in the first measured waveform 200.

[0063] On the other hand, the difference in path distance between the second waveform P12 and the second waveform P13 in the first measured waveform 200 is the same as the difference in path distance between the second waveform P12' and the second waveform P13' in the second measured waveform 200'. This is because the amount of uneven wear is the same, except for the contact position.

[0064] Next, a method and process for improving the detection accuracy of abnormality detection of the cutting ring 41 of the disc cutter 40 using the abnormality detection device 60 will be described with reference to Fig. 16. Steps ST31, ST32, ST37, and ST38 are similar to steps ST11, ST12, ST17, and ST18 in the flowchart shown in Fig. 13. In the embodiment, steps ST36 to ST38 will be described as being performed by a measurer.

[0065] If it is determined that the cutter head 30 has stopped (Yes in step ST32), the ultrasonic sensor 61 is brought into contact with the first contact position X1 of the cutter top 44 of the disc cutter 40 to be measured and measurement is performed (step ST33). The measurer brings the ultrasonic sensor 61 into contact with the first contact position X1 of the cutter top 44 of the disc cutter 40 to be measured. The measurer inputs a measurement start operation to an operation unit (not shown) of the ultrasonic sensor 61. Then, the measurement controller 110 causes the ultrasonic sensor control unit 111 to emit ultrasonic waves from the oscillator 611. Then, the measurement controller 110 receives the signal emitted as a surface wave from the oscillator 611 by the signal receiving unit 112. The measurement controller 110 proceeds to step ST34.

[0066] The ultrasonic sensor 61 is brought into contact with the second contact position X2 of the cutter top 44 of the disc cutter 40 to be measured and measurement is performed (step ST34). The measurer brings the ultrasonic sensor 61 into contact with the second contact position X2 of the cutter top 44 of the disc cutter 40 to be measured. The measurer inputs a measurement start operation to an operation unit (not shown) of the ultrasonic sensor 61. Then, the measurement controller 110 causes the ultrasonic sensor control unit 111 to emit ultrasonic waves from the oscillator 611. Then, the measurement controller 110 receives the signal emitted as a surface wave from the oscillator 611 by the signal receiving unit 112. The measurement controller 110 proceeds to step ST35.

[0067] The two waveforms are displayed on the monitor 62 (step ST35). The measurement controller 110 controls the display control unit 113 to display the two measurement waveforms indicated by the signals received in steps ST33 and ST34 on the monitor 62. The measurement controller 110 proceeds to step ST36.

[0068] The measurer checks the two measurement waveforms displayed on the monitor 62 and determines whether the waveforms have been measured normally (step ST36). The determination of whether the waveforms have been measured normally is the same as in the first embodiment. If the measurer determines that the two waveforms displayed on the monitor 62 have been measured normally (Yes in step ST36), the process proceeds to step ST37. If the measurer does not determine that the two waveforms displayed on the monitor 62 have been measured normally (No in step ST36), the process proceeds to step ST38.

[0069] If it is determined that the two displayed waveforms were measured normally (Yes in step ST36), the measurer determines whether only the first waveform, which is a circular wave that has made one revolution around the cutter top 44, was measured within the expected range (step ST37). The measurer checks the measured waveform displayed on the monitor 62 and determines whether only the first waveform is displayed within the expected range. If only the first waveform is displayed within the expected range, the measurer determines that only the first waveform was measured within the expected range. If it is determined that only the first waveform was measured within the expected range (Yes in step ST37), the measurer proceeds to step ST38. If it is not determined that only the first waveform was measured within the expected range (No in step ST37), the measurer proceeds to step ST40.

[0070] If it is determined that only the first waveform is measured within the expected range (Yes in step ST37), the measurer determines that no abnormality (uneven wear, cracks, chips, etc.) has occurred on the cutter top and that normal wear has occurred, and calculates the wear height (step ST38). The measurer calculates the wear height of the cutter ring 41 from the path distance at which the first waveform, which is thought to be a circulating wave, occurred. The wear height may be calculated using the average path distance of the two waveforms. If the calculated wear height is equal to or less than a threshold, the measurer may determine it to be "normal." If the calculated wear height is greater than the threshold, the measurer may determine it to be "abnormal." The measurement controller 110 may display the wear height and the determination result on the monitor 62 via the display control unit 113. If the measurer confirms the determination result as "abnormal," the measurer interrupts the measurement. Then, the measurer, for example, replaces the disc cutter 40.

[0071] If the measurer determines that either of the two waveforms displayed on the monitor 62 was not measured normally (No in step ST36), the measurer determines that there is a "measurement error" (step ST39). The measurement controller 110 may display the determination result of "measurement error" on the monitor 62 via the display control unit 113. When the measurer confirms the determination result of "measurement error", he or she discontinues the measurement. Then, the measurer checks, for example, the position and orientation of the ultrasonic sensor 61.

[0072] If it is not determined that only the first waveform has been measured within the expected range (No in step ST37), the measurer determines that there may be an abnormality (uneven wear, cracks, chipping, etc.) at the cutter top, and further determines whether multiple second waveforms have been measured in the two waveforms (step ST40). The measurer checks the measured waveform displayed on monitor 62 and determines whether multiple second waveforms are displayed. If it is determined that multiple second waveforms have been measured (Yes in step ST40), proceed to step ST42. If it is not determined that multiple second waveforms have been measured (No in step ST40), proceed to step ST41.

[0073] If the measurer does not determine that multiple second waveforms have been measured (No in step ST40), the measurer determines that "there is a possibility that the ring is cracked or chipped" (step ST41). The measurement controller 110 may cause the display control unit 113 to display the determination result of "there is a possibility that the ring is cracked or chipped" on the monitor 62. When the measurer confirms the determination result of "there is a possibility that the ring is cracked or chipped," the measurer suspends the measurement. Then, the measurer visually checks, for example, whether there is a crack or chip in the disc cutter, and if there is indeed a crack or chip, replaces the disc cutter 40.

[0074] If it is determined that multiple second waveforms have been measured (Yes in step ST40), the measurer determines that "uneven wear is possible" (step ST42). The measurement controller 110 may cause the display control unit 113 to display the determination result of "uneven wear is possible" on the monitor 62. When the measurer confirms the determination result of "uneven wear is possible," the measurer suspends the measurement. Then, the measurer, for example, visually checks whether uneven wear has occurred on the disc cutter, and if uneven wear has indeed occurred, replaces the disc cutter 40.

[0075] [Ultrasonic sensor variation 1] FIG. 17 is a schematic diagram illustrating an example of a state in which the abnormality detection device measures the disk cutter.

[0076] The jig 613 fixes the acrylic material 612 to the disc cutter 40. The inner wall of the jig 613 contacts the side surface of the cutting ring 41 of the disc cutter 40. The jig 613 is arranged in a state where it covers the cutter top 44 of the disc cutter 40 and a portion of the cutting ring 41. The jig 613 shown in FIG. 17 is formed in a rectangular tube shape with walls on the top and sides and an open bottom. The oscillator 611 and the acrylic material 612 are arranged on the upper wall of the jig 613. The cutter top 44 of the disc cutter 40 and a portion of the cutting ring 41 are accommodated in an internal space 613A. According to this modification, the measurer does not need to hold the ultrasonic sensor 61 by hand during measurement. According to this modification, the jig 613 can stabilize the acrylic material 612 with respect to the cutter top 44.

[0077] [Ultrasonic sensor variation 2] Fig. 18 is a schematic diagram illustrating a modified example of the abnormality detection device. The ultrasonic sensor 61 includes a spring 614 in addition to the configuration shown in Fig. 7. The spring 614 moves the acrylic material 612 only in the up and down directions in Fig. 18. According to this modified example, the spring 614 can further stabilize the acrylic material 612 relative to the cutter top 44.

[0078] FIG. 19 is a block diagram showing the configuration of the measurement controller. In the above, steps ST15 to ST17 of the flowchart shown in FIG. 13 and steps ST36 to ST38 of the flowchart shown in FIG. 16 have been described as being performed by a measurer, but these processes may also be performed by the calculation unit 114 of the measurement controller 110. The calculation unit has functions corresponding to steps ST15 to ST17 of the flowchart shown in FIG. 13 or steps ST36 to ST38 of the flowchart shown in FIG. 16. The calculation unit executes these processes, for example, by an algorithm-based program, an inference system using AI (Artificial Intelligence), or machine learning. The description of the computer system 1000 described above with reference to FIG. 12 also applies to the measurement controller 110 shown in FIG. 19.

[0079] FIG. 20 is a block diagram showing the configuration of the measurement controller. In the above, steps ST15 to ST21 of the flowchart shown in FIG. 13 and steps ST36 to ST42 of the flowchart shown in FIG. 16 have been described as being performed by a measurer, but these processes may also be performed by the abnormality detection unit 115 of the measurement controller 110. The abnormality detection unit has functions corresponding to steps ST15 to ST21 of the flowchart shown in FIG. 13 and steps ST36 to ST42 of the flowchart shown in FIG. 16. The abnormality detection unit executes these processes, for example, by an algorithm-based program or an inference system using AI or machine learning. The description of the computer system 1000 described above with reference to FIG. 12 also applies to the measurement controller 110 shown in FIG. 20.

[0080] 13 and steps ST33 and ST34 of the flowchart shown in Fig. 16 have been described above as the case where the measurer brings the acrylic material 612 of the ultrasonic sensor 61 into contact with the cutter top 44 of the disc cutter 40 to be measured, but this is not limiting. A moving mechanism including an actuator that moves the ultrasonic sensor 61 to a desired position relative to the disc cutter 40 may be provided, and the actuator may be driven by the drive controller 100 to move the ultrasonic sensor 61.

[0081] Although the drive controller 100 and the measurement controller 110 are described above as separate units, the present invention is not limited to this. The drive controller 100 and the measurement controller 110 may be integrated. [Explanation of symbols]

[0082] 1...tunnel boring machine, 10...main body, 20...belt conveyor, 29...drive motor, 30...cutter head, 32...case, 40...disc cutter, 41...cutting ring, 42...hub, 43...retainer (holding part), 44...cutter top, 60...abnormality detection device, 61...ultrasonic sensor, 611...oscillator, 612...acrylic material, 62...monitor (display part), 100...drive controller, 101...drive motor control part, 110...measurement controller, 111...ultrasonic sensor control part, 112...signal receiving part, 113...display control part, 200...measured waveform, A...circumferential direction, P11...first waveform, P12...second waveform, P13...second waveform, Q...expected range.

Claims

1. An abnormality detection method for detecting an abnormality in a disc cutter of a stationary tunnel boring machine, comprising: an ultrasonic sensor is brought into contact with a cutter top of the disc cutter, and a surface wave is emitted along the circumferential direction of the cutter top; receiving a signal transmitted from and returned to the ultrasonic sensor; detecting an abnormality occurring on the outer periphery of the disc cutter from the received signal; Anomaly detection methods.

2. The abnormality is at least one of uneven wear, ring cracking, and chipping. The anomaly detection method according to claim 1 .

3. Detecting an abnormality occurring in front of the disc cutter. The abnormality detection method according to claim 1 or 2.

4. calculating a wear height of the disc cutter based on a surface wave path distance of a peak value of a first waveform, which is a circumferential wave, detected from the received signal within an assumed range, which is an assumed circumferential length of the disc cutter; The anomaly detection method according to claim 1 .

5. Calculating the circumferential length of the outer periphery of the disc cutter from the received signal to calculate the wear height; The anomaly detection method according to claim 4 .

6. If the received signal indicates that the first waveform detected within the expected range and a plurality of second waveforms different from the first waveform have been measured, it is determined that there is a possibility of uneven wear. The abnormality detection method according to claim 4 or 5.

7. If the received signal indicates that the first waveform detected within the expected range and one second waveform different from the first waveform are measured, it is determined that there is a possibility of a ring crack or chip. The anomaly detection method according to any one of claims 4 to 6.

8. the second waveform has a lower peak value than the first waveform; The abnormality detection method according to claim 6 or 7.

9. receiving a first contact position signal transmitted from the ultrasonic sensor in a state where the ultrasonic sensor is in contact with a first contact position on the cutter top, and a second contact position signal transmitted from the ultrasonic sensor in a state where the ultrasonic sensor is in contact with a second contact position on the cutter top that is different from the first contact position; detecting the abnormality based on the first contact position signal and the second contact position signal; The anomaly detection method according to any one of claims 1 to 8.

10. An abnormality detection device for measuring wear on a disc cutter of a stationary tunnel boring machine, an ultrasonic sensor that comes into contact with a cutter top of the disc cutter and emits a surface wave along the circumferential direction of the cutter top; a signal receiving unit that receives a signal transmitted from the ultrasonic sensor and returned to the ultrasonic sensor; an abnormality detection unit that detects an abnormality occurring on the outer periphery of the disk cutter based on the signal received by the signal receiving unit; An abnormality detection device comprising:

11. The anomaly detection unit calculates the anomaly using either an algorithm-based program, an AI (Artificial Intelligence) or an inference system using machine learning. The abnormality detection device according to claim 10.

12. An abnormality detection device for measuring wear on a disc cutter of a stationary tunnel boring machine, an ultrasonic sensor that comes into contact with a cutter top of the disc cutter and emits a surface wave along the circumferential direction of the cutter top; a signal receiving unit that receives a signal transmitted from the ultrasonic sensor and returned to the ultrasonic sensor; a calculation unit that calculates the circumferential length of the outer periphery of the disk cutter based on the signal received by the signal receiving unit; An abnormality detection device comprising:

13. The calculation unit calculates using an algorithm-based program, an inference system using AI (Artificial Intelligence) or machine learning. The abnormality detection device according to claim 12.

14. 1. A tunnel boring machine in which wear of a disc cutter is measured while stationary, comprising: The main body and a cutter head installed in front of the main body for excavating rock; a disk cutter provided in front of the cutter head and rotatably supported with respect to the cutter head; an ultrasonic sensor that comes into contact with a cutter top of the disc cutter and emits a surface wave along the circumferential direction of the cutter top; a signal receiving unit that receives a signal transmitted from the ultrasonic sensor and returned to the ultrasonic sensor; an abnormality detection unit that detects an abnormality occurring on the outer periphery of the disk cutter based on the signal received by the signal receiving unit; A tunnel boring machine comprising:

15. 1. A tunnel boring machine in which wear of a disc cutter is measured while stationary, comprising: The main body and a cutter head installed in front of the main body for excavating rock; a disk cutter provided in front of the cutter head and rotatably supported with respect to the cutter head; an ultrasonic sensor that comes into contact with a cutter top of the disc cutter and emits a surface wave along the circumferential direction of the cutter top; a signal receiving unit that receives a signal transmitted from the ultrasonic sensor and returned to the ultrasonic sensor; a calculation unit that calculates the circumferential length of the outer periphery of the disk cutter based on the signal received by the signal receiving unit; A tunnel boring machine comprising:

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