JP2013083640A - Apparatus and method for diagnosing crack of crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crane crack diagnosing apparatus and its method capable of remotely and efficiently inspecting cracks existing in a crane in a nondestructive state about a crane such as a ceiling crane including beams (a main beam and a traveling beam) and rails raid on the beams.SOLUTION: In order to diagnose cracks on a traveling beam 1 of a crane, a crane crack diagnosing apparatus 5 includes an ultrasonic vibration generation device 6, an infrared thermography device 11, a reflector 13, and a rail fixing device 19.

Description

  The present invention relates generally to a diagnostic apparatus and method for diagnosing abnormalities such as cracks occurring in a crane traveling girder and a main girder, and in particular, cracks occurring when ultrasonic vibration is applied to a crack in a member. The present invention relates to a crack diagnosis apparatus and method for detecting temperature fluctuations of an image using an infrared thermography apparatus.

  For example, in a steelmaking line in an ironmaking plant, a large overhead crane is provided to transport hot metal ladle. The traveling girder, which is a supporting part of these cranes, and the main girder, which is a conveying part, are subjected to a great load due to the crane's own weight and the weight of the hot metal ladle during operation, and fatigue cracks are generated. These cracks develop with long-term use, causing breakage of the girder and dropping of the crane carriage. Conventionally, various methods have been proposed as means for diagnosing cracks in girders.

  That is, as a method for inspecting abnormalities such as cracks occurring in large structures such as overhead cranes and cargo handling machines, magnetic particle flaw detection, penetration flaw detection, and infrared method are widely used.

  Here, in the magnetic particle flaw detection and the penetrant flaw detection, the position of the crack can be visualized by the magnetic powder and the penetrant, but the accuracy of the crack diagnosis is not high and the inspection takes a long time. Furthermore, these inspection methods need to be close to the inspection object. Therefore, in order to inspect these devices in high places, it is impossible to inspect without a scaffold. The creation of this scaffold requires very high costs and labor.

  Infrared method is a method of measuring the heat generated by cracks when an input is given to a crack with an infrared thermography device.It uses the fluctuation in stress caused by the weight of the crane carriage and the amount of suspension load when the crane is running. A method has been performed in which stress-concentrated heat generated in a crack is measured with an infrared thermography device, and a crack can be inspected remotely (for example, Patent Document 1).

  There is also a method of irradiating a measurement object with microwaves and detecting a crack from a temperature difference appearing on the surface (for example, Patent Document 2).

  In addition, there is a method of detecting a crack as a high temperature part by applying a pulsed current to the object to be measured, measuring heat generated by the current diffracting the crack by infrared thermography (for example, Patent Document 3). .

JP 2007-163390 A JP 2005-249536 A Japanese Patent Laid-Open No. 03-154857

  However, since the method described in Patent Document 1 uses stress heat generation caused by stress fluctuations per hour, large stress fluctuations must be given in a very short time. Therefore, an infrared thermography device that can measure at a high speed is required. In addition, since the range in which the effective stress fluctuation is caused by traveling the crane is a limited range just below the crane wheel, the crane must be run several times to inspect the wide range, and the inspection efficiency is poor. There is a problem of becoming.

  In addition, the method described in Patent Document 2 cannot be applied to metal because discharge occurs. Therefore, it cannot be used for steel structures. Moreover, since the frequency of the microwave is close to the radio frequency for controlling a large structure such as a crane, there is a problem that it may cause a malfunction.

  Further, in the method described in Patent Document 3, in the case of a closed crack in which the crack is closed, an electric current passes through the crack contact surface and almost no heat is generated. Therefore, the crack needs to be opened. The cracks in the crane to be inspected are mainly fatigue cracks due to repeated loads, and this is a closed crack, and this method cannot be applied. In addition, there is a problem in that the inspection efficiency is poor because the current range of a magnitude that generates crack heat when current is passed is very narrow.

  The present invention has been made in view of the circumstances as described above, and a crane including a girder (main girder, traveling girder) and a rail installed on the girder, such as an overhead crane, It is an object of the present invention to provide a crane crack diagnosis apparatus and method capable of non-destructively and remotely inspecting cracks existing in the crane efficiently.

  In order to solve the problems of the prior art as described above, the present inventors measured the temperature fluctuation of the cracked portion generated when ultrasonic vibration was applied to the crane surface, by using an infrared thermography device. Decided to detect. The principle of this crack detection is as follows.

  First, when ultrasonic vibration is applied to the surface of the object to be measured and the object to be measured has a crack, the interface of the crack (the interface of the crack surface) is rubbed by the ultrasonic vibration to generate heat. The temperature distribution of the object to be measured is measured with an infrared camera, and the heat generation part is measured as a crack. Further, the heat generated from the crack portion by the ultrasonic vibration can be reflected by the reflector. Therefore, even for cracks in parts where it is difficult to measure the temperature directly with an infrared camera, such as blind spots of structures and obstacles, heat is generated by applying ultrasonic vibration, and the heat is taken out from a measurable angle, and infrared It can be reflected using a reflector in the direction of the camera and detected by an infrared camera.

  In addition, since this method utilizes frictional heat generation at the crack interface, it is very suitable for finding a fatigue crack that is a closed crack. However, even in an open crack other than a closed crack, since the crack tip is always closed, the crack tip can be heated by ultrasonic vibration to detect the crack.

  Based on the above basic concept, the present invention has the following features.

  [1] A crack diagnostic apparatus for nondestructively and remotely inspecting a crack that is present in a crane having a girder and a rail installed on the girder, wherein ultrasonic vibration is generated by contacting the surface of the crane. An ultrasonic vibration generator for applying the ultrasonic wave, and a surface temperature detecting means for measuring a temperature change generated on the surface of the crane by infrared thermography. The ultrasonic vibration generator includes an ultrasonic vibrator that generates ultrasonic waves, A metal ultrasonic horn for amplifying the sound wave amplitude, and a rail fixing device for clamping the ultrasonic vibration generating device to the rail, the rail fixing device, wherein the ultrasonic vibration generating device includes the rail fixing device. A fixed claw for preventing rotation to the center and a pressurizing device for bringing the ultrasonic horn into contact with the crane surface with an arbitrary load, and contacting the ultrasonic horn with the crane surface. Crane crack diagnostic apparatus characterized by applying ultrasonic vibrations by.

  [2] The rail fixing device can use any one of a hydraulic type, a pneumatic type, and a screw type, so that the opening width can be arbitrarily set. The crane crack diagnosis apparatus according to [1], wherein the ultrasonic vibration generator can be clamped and fixed with a pressing load.

  [3] The pressurizing device uses any one of hydraulic pressure, pneumatic pressure, or a pressurizing screw, and the contact pressure between the ultrasonic horn and the crane surface is set to an arbitrary value. The crane crack diagnosis apparatus according to [1] or [2].

  [4] The crane crack diagnosis apparatus according to [3], wherein the pressurizing screw can derive a contact pressure between the ultrasonic horn and the crane surface by measuring a fastening torque.

  [5] The crane crack diagnostic apparatus according to any one of [1] to [4], wherein the ultrasonic vibration generator has a function of traveling on the rail when the apparatus is moved.

  [6] The above-mentioned [1] to [5], wherein the fluctuation temperature distribution data measured by the infrared thermography device is extracted using the oscillation signal of the ultrasonic vibration generator as a reference signal, and lock-in processing is performed. ] The crane crack diagnostic apparatus in any one of.

  [7] A crack diagnosis method for non-destructively and remotely inspecting cracks existing in a crane having a girder and a rail installed on the girder, wherein the ultrasonic vibration generator is brought into contact with the crane surface with a predetermined contact After contact with pressure, ultrasonic vibration is applied to the crane surface by the ultrasonic vibration generator and the frictional heat at the crack interface is excited by the vibration, and the temperature change generated on the girder surface is measured by infrared thermography. And detecting a temperature singular part having the same phase as the excitation cycle as a crack.

  In the present invention, for a crane having a girder (main girder, traveling girder) and a rail installed on the girder, such as an overhead crane, the cracks existing in the crane are non-destructively and remotely efficient. It can be inspected well.

  That is, in the present invention, it is possible to perform a remote crack inspection in a state where a scaffold that is impossible with magnetic particle inspection or penetration inspection is not assembled. Also, since ultrasonic vibration propagates over a wide range, it excites a wide range of crack heat generation compared to the infrared thermoelastic method, which can generate heat only within a limited range without moving the ultrasonic vibration generator. The inspection efficiency is high.

It is a side view which shows one Embodiment of this invention. It is a principal part enlarged view in one Embodiment of this invention.

  An embodiment of the present invention will be described with reference to the drawings. In this embodiment, a case where a crack diagnosis device is attached to a crane carriage traveling rail of a traveling girder of an overhead crane and a traveling girder is diagnosed will be described as an example.

  FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is an enlarged front view of a main part thereof.

  As shown in FIG. 1, generally, in a steel product transport line, a crane carriage 3 travels on a traveling rail 4 installed on a traveling beam 1 supported by a traveling beam column 2 and loads a load. Move.

  And in one Embodiment of this invention, in order to diagnose the crack of the traveling girder 1, the crane crack diagnostic apparatus 5 is the ultrasonic vibration generator 6, the infrared thermography apparatus 11, the reflecting plate 13, and a rail. And a fixing device 19.

  An ultrasonic vibration generating device 6 is installed on the traveling rail 4 on the crane traveling beam 1 via a rail fixing device 19. The ultrasonic vibration generator 6 includes an ultrasonic transducer 6a and an ultrasonic horn 6b. The ultrasonic vibration is generated when an electrical signal is sent to the ultrasonic transducer 6a and is amplified via the ultrasonic horn 6b. Then, ultrasonic vibration can be incident on the crane traveling beam 1 by bringing the ultrasonic horn 6b into contact with the surface of the crane traveling beam 1. The ultrasonic vibration generating device 6 has a mechanism for maintaining stability in the plane direction and the vertical direction by fixing the ultrasonic vibration generating device 6 to the traveling rail 4 on the crane traveling beam 1 via the rail fixing device 19.

  The infrared thermography apparatus 11 includes an infrared camera 7, a personal computer 8, a display unit 9, and a lock-in processor 10. The infrared camera 7 is installed so that the distance to the crane traveling beam 1 to be inspected is 10 to 30 m. When the ultrasonic vibration generator 6 is activated, heat is generated in the crack 12 due to friction at the interface of the crack surface. The infrared camera 7 measures the temperature distribution of the crane traveling beam 1 at this time and transmits the information to the personal computer 8. Further, the output oscillation signal from the ultrasonic vibration generator 6 is input to the Lock-in Processor 10. In the lock-in processor 10, the oscillation signal output from the ultrasonic vibration generator 6 is used as a reference signal, and the lock-in process is performed on the temperature fluctuation of the crack 12 measured by the infrared camera 7. Displayed on the display unit 9. By using this lock-in process, temperature fluctuations that change in a phase different from that of the oscillation of the ultrasonic vibration generator 6 can be removed, so that inspection accuracy is improved.

  Further, in the reflector 13, when the crack 12 in the crane traveling girder 1 to be inspected becomes a blind spot of the crane carriage 3 and the traveling girder support 2 and the infrared rays emitted from the crack 12 cannot be measured by the infrared camera 7, In order to reflect infrared rays in the direction of the infrared camera 7, it is installed on the crane traveling beam 1. The reflecting plate 13 is made of aluminum, and it is desirable that the surface is mirror-finished in order to reflect infrared rays with high efficiency.

  As shown in FIG. 2, the rail fixing device 19 includes a clamping device 14, a clamping force adjusting mechanism 15, a fixing claw 16, a slider 17, and a pressurizing screw 18. By operating the mechanism 15, the clamp device 14 can be clamped and fixed to the rail 4 with an arbitrary force. By adjusting the clamping force adjusting screw 15, the opening width of the rail fixing device 19 can be arbitrarily adjusted, so that the device can be fixed to a portion having a different rail width. Further, by tightening the pressurizing screw 18, the slider 17 is pushed out, and the ultrasonic vibration generator 6 can be pressed against the surface of the crane traveling beam 1. When the clamping device 14 is fastened to the rail 4, by measuring the torque of the pressurizing screw 18 (for example, it can be measured with a torque wrench), the pressing force is calculated from the relationship between the previously determined fastening torque and the pressing force, The pressing force can be adjusted to an arbitrary value. Further, the fixing claw 16 is placed on the lower surface of the rail 4 so that the rail fixing device 19 does not rotate around the rail 4 by a reaction force when the ultrasonic horn 6b is pressed against the crane traveling beam 1 with an arbitrary force. It has a mechanism that prevents contact and rotation.

  Here, as described above, when the ultrasonic vibration generator 6 (ultrasonic transducer 6a, ultrasonic horn 6b) is pressed against the surface of the crane traveling beam 1, the pressing force can be adjusted as follows. Based on reasons like that.

  That is, according to the inspection object, the ultrasonic transducer 6a and the ultrasonic horn 6b of the ultrasonic vibration generator 6 are replaced with different ones, and the frequency of the incident ultrasonic wave is set to an appropriate value. The larger the pressing force when pressing the ultrasonic vibrator 6a and the ultrasonic horn 6b against the surface of the crane traveling beam 1, the more heat is generated in the crane traveling beam 1, but the machine of the ultrasonic vibrator 6a and the ultrasonic horn 6b is increased. This is because it is appropriate to set an appropriate pressing force in consideration of the mechanical strength.

  Instead of the pressurizing screw 18, a hydraulic jack, a pneumatic jack, or the like may be used, and the pressing force thereby measured may be measured with a load cell to adjust the pressing force. However, it is preferable to use the pressurizing screw 18 as described above because it can be easily installed.

  Further, when the ultrasonic vibration generating device 6 has a function of traveling on the rail 4 when the device is moved, the inspection can be performed more efficiently.

  And when diagnosing the crack of the traveling beam 1 using the crane crack diagnostic device 5 configured as described above, the ultrasonic vibration generator 6 is brought into contact with the surface of the crane traveling beam 1 with a predetermined contact pressure. Thereafter, an ultrasonic vibration is applied to the surface of the crane traveling beam 1 by the ultrasonic vibration generator 6 and the frictional heat at the crack interface is excited by the vibration, and the temperature change generated on the surface of the crane traveling beam 1 is analyzed by the infrared thermography 7. And a step of detecting a temperature singular part having the same phase as the excitation cycle as a crack.

  In this way, in this embodiment, it is possible to inspect cracks existing in the traveling beam of the overhead crane non-destructively and efficiently remotely.

  In this embodiment, the traveling girder of the overhead crane is targeted. However, the present invention is not limited thereto, and is applied to a crane including a girder and a rail installed on the girder. can do.

1 Traveling girder 2 Traveling girder support 3 Crane truck 4 Rail (traveling rail)
DESCRIPTION OF SYMBOLS 5 Crane crack diagnostic apparatus 6 Ultrasonic vibration generator 6a Ultrasonic vibrator 6b Ultrasonic horn 7 Infrared camera 8 Personal computer 9 Display part 10 Lock-in Processor
DESCRIPTION OF SYMBOLS 11 Infrared thermography apparatus 12 Crack 13 Reflector 14 Clamp apparatus 15 Clamping force adjustment mechanism 16 Fixing claw 17 Slider 18 Pressure screw 19 Rail fixing apparatus

Claims (7)

  A crack diagnosis apparatus for non-destructively and remotely inspecting a crack existing in a crane having a girder and a rail installed on the girder, and for applying ultrasonic vibration by contacting the surface of the crane A vibration generator, and a surface temperature detecting means for measuring a temperature change generated on the surface of the crane by infrared thermography. The ultrasonic vibration generator includes an ultrasonic vibrator that generates ultrasonic waves, and an ultrasonic amplitude. A metal ultrasonic horn for amplifying and a rail fixing device that clamps and fixes the ultrasonic vibration generating device to a rail. The rail fixing device rotates the ultrasonic vibration generating device around the rail fixing device. A fixed claw that prevents the ultrasonic horn from contacting with the crane surface with an arbitrary load, and the ultrasonic horn is brought into contact with the crane surface. Crane crack diagnostic apparatus characterized by applying ultrasonic vibration by.   The rail fixing device can be set to an arbitrary opening width by using any one of hydraulic, pneumatic, or screw type, and with an arbitrary pressing load against a rail having an arbitrary width. The crane crack diagnosis apparatus according to claim 1, wherein the ultrasonic vibration generator can be clamped and fixed.   The pressurizing device uses any one of hydraulic pressure, pneumatic pressure, or a pressurizing screw, and the contact pressure between the ultrasonic horn and the crane surface is set to an arbitrary value. Or the crane crack diagnostic apparatus of 2.   The crane crack diagnosis apparatus according to claim 3, wherein the pressurizing screw can derive a contact pressure between the ultrasonic horn and the crane surface by measuring a fastening torque.   The crane crack diagnosis apparatus according to any one of claims 1 to 4, wherein the ultrasonic vibration generator has a function of traveling on the rail when the apparatus is moved.   6. The lock-in process is performed by taking out fluctuating temperature distribution data measured by the infrared thermography device using an oscillation signal of the ultrasonic vibration generator as a reference signal, and performing lock-in processing. Crane crack diagnostic equipment.   A crack diagnosis method for non-destructively and remotely inspecting a crack provided in a crane having a girder and a rail installed on the girder, and contacting the ultrasonic vibration generator with a predetermined contact pressure on the crane surface After that, the ultrasonic vibration is applied to the crane surface by the ultrasonic vibration generator, the frictional heat at the crack interface is excited by the vibration, and the temperature change generated on the girder surface is measured by infrared thermography. And detecting a temperature singular part having the same phase as the oscillation cycle as a crack.

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