KR101843890B1 - Apparatus for Diagnosis Defect of Steel Structures and Weld - Google Patents

Abstract

The present invention relates to a diagnosis apparatus which nondestructively detects a defect in a steel material and a welded portion of a bridge or the like made of steel structures by using a hall sensor. The diagnosis apparatus which nondestructively detects a defect in a steel material and a welded portion of a bridge made of steel structures by using a hall sensor comprises: a flat-type sensor head (10) provided with a printed circuit board (11) with a through hole (12) formed at the center and a plurality of coupling grooves (13) formed at regular intervals in a lower end, the hall sensor (14) fixed and coupled to the coupling grooves (13) to detect a magnetic field in the perpendicular direction, a flat-type plate (15) inserted into the through hole (12), and magnets (16) provided on both lower ends of the flat-type plate (15); a moving carriage (20) provided with a case (21), of which the sensor head (10) is embedded on a lower portion, and a plurality of wheels (22) coupled to one side of the case (21) to be able to rotate; a data logger (31) mounted on the moving carriage (20) and storing data collected from the sensor head (10); and a signal processing control unit (30) for converting and processing a sensing signal inputted from the hall sensor (14) of the sensor head (10) and controlling power applied to the sensor head (10). The present invention enables nondestructive inspection of the entire steel structures rather than a local area with the diagnosis apparatus of a steel structure for a bridge, which can be easily carried by an inspector. It is possible to store more objective data and save time and costs for the inspection.

Description

[0001] Apparatus for Diagnosis Defect of Steel Structures and Weld [0002]

The present invention relates to an apparatus for diagnosing faults in steel structures and welds, and more particularly, to a diagnosis apparatus for non-destructively inspecting defects of a steel material such as a bridge made of a steel structure and welds using a hall sensor.

In general, the 'Special Law on Facility Safety Management' currently controls the bridge of steel structures regularly for regular inspection, precision inspection, and precision safety diagnosis. Furthermore, bridges of steel structures include weld failure, corrosion, and nondestructive inspection including defects, cracks, omissions, etc., for safety inspection. Moreover, fatigue cracks are generated by repeated loads in steel structures. In the case of fatigue cracks, most stresses occur in the region where stresses are concentrated.

The non-destructive inspection methods used to inspect defects in welds are visual inspection (VT), penetration test (PT), ultrasonic inspection (UT), radiographic inspection (RT) , And magnetic particle inspection (MT).

In the case of precise inspection of steel structures, in the material test items, defects of steel welds are to be subjected to magnetic particle test and ultrasonic inspection at a minimum of one point per 50 m. In large and wide bridge girders, The safety of the entire girder is confirmed only by the inspection of the girder.

Also, even in the case of precise safety diagnosis, the magnetic particle test and the radiation penetration test of the welded part of the weld shall be carried out at least 1 point for 50 m for the deep part and the butt weld part of the crack, 1 point for each girder per plate girder bridge span, Investigation and quantity should be determined at the spot.

In addition, the existing non-destructive inspection is complicated and time-consuming to remove the coating on the steel surface, to smooth the surface, to block the structure from the outside, to transmit the radiation, to spray the magnetic powder on the damaged surface, There is a disadvantage in that it takes a long time to check the reliability of the entire bridge girder.

Therefore, the following problems related to the safety check of steel structures were exposed. In other words, the inspection of the steel structure is based on visual inspection (VT) and the nondestructive inspection is performed on the deep part of the crack. The steel box girder is not visible because the inside is dark. . In addition, it is difficult for the investigator to confirm the minute cracks such as fatigue cracks by the visual inspection inside the steel box girder, and it is difficult to judge the safety of the whole structure based on the nondestructive inspection A significant error has occurred. In addition, it has been impossible in the time and space to perform the safety check of the entire steel structure using the nondestructive testing equipment and the manpower that are currently being implemented.

As a prior art related to the present invention, Patent Document 1 discloses a welding apparatus that includes a first welding object, a moving body that moves along a welded portion of the second welding object, and a welding portion coupled to one side portion of the moving body, A second sensor coupled to the other side of the moving body for inspecting the welded portion in contact with the second object to be welded, and a second sensor for attaching the moving body to the first and second objects to be welded by magnetic force A sensor transporting apparatus for inspecting a welded portion including a body is disclosed.

In addition, Patent Document 2 discloses a welding apparatus for welding a welding wire, which comprises a main body having a driving unit for driving wheels, a sensing unit provided in the main body for sensing a weld line formed on an object to be welded, And a control unit for controlling the driving unit to move the welding unit along the weld line tracking apparatus.

Korean Patent Publication No. 10-2016-0135613 (published on November 28, 2016) Korean Registered Patent No. 10-1069790 (issued October 10, 2011)

In order to solve the above problems, it is an object of the present invention to easily and quickly precisely survey the steel structure so as to secure the reliability of the steel structure while checking steel structures such as bridges as if they were visually inspected to be.

In addition, cracks occurring in steel structures such as bridges are periodically inspected to confirm minute cracks caused by fatigue cracks and the like, and reinforcements can be reinforced before cracks are enlarged, thereby preventing unpredictable accidents such as brittle fracture Another purpose is to prevent the maintenance costs from increasing due to reinforcing the large damage.

In order to achieve the above object, according to the present invention, there is provided a printed circuit board comprising: a printed circuit board having a through hole formed at a center thereof and having a plurality of coupling grooves formed at a predetermined interval at a lower end thereof; a Hall sensor fixedly coupled to the coupling groove, A plate type sensor head having a flat plate inserted into the through hole and a magnet coupled to both lower ends of the plate; A case in which the sensor head is housed at a lower portion thereof, and a moving truck comprising a plurality of wheels coupled to one side of the case and configured to rotate; A data logger installed in the moving vehicle and storing data collected by the sensor head; And a signal processing controller for converting and processing the sensing signal input from the hall sensor of the sensor head and controlling the power applied to the sensor head.

Further, the present invention may further include a display mounted on one side of the moving truck to visually display an operating state, a handle configured on the moving truck, and a battery for supplying power necessary for operation of the components installed on the moving truck can do.

Further, in the present invention, an electric motor may be installed in the moving bogie, and a controller may be used to control the moving bogie from a remote location.

Further, in the present invention, the Hall sensor of the sensor head may be installed at a predetermined interval from the surface of the object to be sensed.

In addition, in the present invention, the magnetization direction of the hall sensor is set in a traveling direction and a diagonal direction of the moving carriage, and the sensing performance may be cos (a Hall sensor traveling direction and a magnetization direction angle) value.

According to the present invention, a metal object is magnetized using a magnet, and leakage of magnetic flux due to defects of a steel material or a welded portion of the steel structure is detected, thereby displaying a display using a visualized image, It is possible to improve the efficiency of maintenance due to the damage of the steel material and the welded part of the steel structure due to the rapid judgment and response of the inspectors and to carry out the nondestructive investigation of the entire steel structure instead of the local survey, And the time and cost saving effect can be expected.

1 is a perspective view showing a Hall sensor array in a steel structure safety diagnosis apparatus for a bridge according to an embodiment of the present invention.
2 is a perspective view showing a flat type sensor head in a steel structure safety diagnosis apparatus for bridges according to the present invention.
FIG. 3 is a perspective view showing a plate-type sensor head installed on a moving carriage in a steel structure safety diagnosis apparatus for bridges according to the present invention.
4 is a block diagram showing the main configuration of a steel structure safety diagnostic apparatus for bridges according to the present invention.
5 is a schematic view showing a principle of detecting damage using a Hall sensor of a flat type sensor head in a steel structure safety diagnosis apparatus for bridges according to the present invention.
6A and 6B are schematic views illustrating the detection of damage to a steel material and a welded portion of a steel structure of a steel structure safety diagnostic device for a bridge according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a safety device for a steel structure for bridges according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, the flat type sensor head 10 is integrally coupled with a hall sensor array of a structure of a printed circuit board (PCB) 11 and a magnetization-based magnetization yoke.

That is, the Hall sensor array is divided into a printed circuit board 11 and a Hall sensor 14, and a through hole 12 is formed in the center of the printed circuit board 11 in the horizontal direction. The printed circuit board 11 is used in a substantially perpendicular direction. A plurality of coupling grooves 13 are formed at the lower end of the printed circuit board 11 at regular intervals. The length of the printed circuit board 11 is about 90 mm, and the width of the coupling groove 13 is about 6 mm. Further, the Hall sensor 14 is fixedly coupled to the coupling groove 13 to sense a magnetic field in a perpendicular direction. The Hall sensor 14 is composed of a Hall sensor array of 20 channels by applying approximately 20 to the lower end of the printed circuit board 11, but it may be added or subtracted depending on a detection range, a diagnosis part, or the like. The magnet-based magnetization yoke is provided with a flat plate 15 inserted into the through hole 12 of the printed circuit board 11 and a magnet 16 coupled to the lower ends of both sides of the plate 15. A carbon steel plate is applied to the plate 15 in the form of a flat plate. The magnet 16 is preferably a permanent magnet made of a neodymium material, which is a ferromagnetic material. Further, the magnet 16 may be applied with an electromagnet magnetized by an applied electric energy.

3, the moving carriage 20 is integrally coupled to a case 21 in which the sensor head 10 is housed in the lower portion and a plurality of wheels 22 coupled to one side of the case 21 to rotate. A pair of wheels 22 are axially coupled to the rotating shaft passing through the case 21 on the front and rear sides of the case 21, respectively. It is preferable to mount the hall sensor 14 on the bottom surface of the case 21 such that the hall sensor 14 is closely contacted or exposed through the case 21. [ The movable carriage 20 may be constructed so as to be capable of moving at a constant speed and capable of improving the diagnostic accuracy of the steel structure 100.

Further, the Hall sensor 14 of the sensor head 10 is installed at a predetermined interval from the surface of the object to be sensed. That is, the hole sensor 14 of the sensor head 10 can adjust the diameter of the wheel 22 or adjust the height of the wheel 22 to adjust the distance between the sensor and the surface of the object, such as steel or welding, The height of the sensor head 10 fixed to the case 21 can be adjusted to adjust the sensing distance with respect to the sensing object.

4, a data logger (DAQ) 31 is installed in the mobile truck 20 and stores data collected by the sensor head 10. The data logger (DAQ) The signal processing control unit 30 converts and processes the sensing signal input from the hall sensor 14 of the sensor head 10 and controls the power applied to the sensor head 10. [ A display 32 for visually displaying the operating state of the sensor head 10 is mounted on one side of the moving carriage 20 and a handle 32 for holding and holding the moving carriage 20 is mounted on the moving carriage 20, (23). In addition, a battery 34 for supplying power necessary for operation of the components installed in the mobile truck 20 is included. The secondary battery is preferably used as the battery, but a rechargeable battery such as a battery can be used.

Further, it may include a controller provided with an electric motor on the moving carriage 20, and a remote controller for wirelessly moving the moving carriage 20. That is, the mobile truck 20 is remotely controlled by a controller, and the electric motor is driven to enable the wheel 22 to rotate forward or reverse, or change direction. In addition, a camera may be installed on the moving carriage 20 so as to be capable of transmitting / receiving images in the moving direction of the moving carriage 20 remotely.

The operation of the thus-constructed steel structure safety diagnostic apparatus 1 according to the present invention will be described.

First, in FIG. 5, a damage is detected in the steel material 101, the welded portion 102, and the like of the steel structure 100 using the Hall sensor of the flat type sensor head. That is, in a safety device based on magnetic sensing, when a metal object is magnetized using the magnet 16, a magnetic field is formed between the magnets 16, at which time magnetic flux leaks from the defective portion of the specimen. This leakage is measured by the hall sensor 14 to detect defects. The intensity of the leaked magnetic flux can be measured by the Hall sensor 14. When the Hall sensor 14 is placed in the magnetic field, Hall voltage is generated in a direction perpendicular to the magnetic field and the current, The damage location and size can be estimated. Based on a visualized image based on the magnetic field, and displays an alarm on the display 32. Thus, it is possible to promptly determine and respond to the situation through the alarm, so that the steel material of the steel structure and the welded portion Improvement of the efficiency of maintenance of damage is expected.

In Fig. 6A, a damage of the steel material 101 is detected at the girder of the steel structure for bridges by the moving truck 20. That is to say, the inspector can set the defective portion 103 of the steel material 101 in a plurality of arrays while moving the moving carriage 20 on the steel material 101 and holding the handle 23 to move the surface of the steel material 101 at a constant speed The Hall sensor 14 of the sensor head 10 detects the magnetic flux. The detection signal detected by the hall sensor 14 is input to the signal processing control unit 30. [ The signal processing control unit 30 converts the input sensing signal into a video signal by performing an installed algorithm and processes the sensed signal. The signal processed in the signal processing control unit 30 is displayed through the display 32. [ The signal processed by the signal processing control unit 30 is stored in the data logger 31. [

In Fig. 6B, the movable truck 20 detects defects in the welded portion 102 welded with the steel material of the steel structure for the bridge and the steel material. At this time, the inspector checks defects of the welded portion 102 while the hall sensor 14 of the sensor head 10, which is designed in a plurality of arrays, while moving the moving carriage 20 at a constant speed over the welded portion 102 between the steel members 101 Detects magnetic flux. The detection signal detected by the hall sensor 14 is input to the signal processing control unit 30, converted and processed, and then displayed on the display 32 and stored in the data logger 31. Therefore, the signal processing control unit 30 should be provided with an optimized algorithm for analyzing the characteristics and the damage type, in addition to the optimized configuration for the diagnosis of the steel material 101 and the welded part 102 of the steel structure.

On the other hand, defects of the welded portion 102 are mainly horizontal to the welded portion, and defects are generated in a length longer than a certain length in the horizontal direction. Therefore, a narrow defect in the direction perpendicular to the weld is unlikely to occur.

Therefore, it is preferable that the magnetization direction of the hall sensor 14 for diagnosis of the welded portion is arranged in the advancing direction and the diagonal direction, approximately 45 degrees. Furthermore, it has about half the sensitivity of the signal detected in the damage of the shape perpendicular to the traveling direction. At this time, the sensing performance is cos (angle between the sensor traveling direction and the magnetization direction).

As described above, the steel structure safety diagnosis apparatus (1) for bridges of the present invention enables non-destructive investigation of the entire steel structure rather than a local survey from a steel structure safety diagnostic apparatus for bridges, which can easily be carried by a tester, And costs can be saved.

While the invention has been shown and described with respect to the specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Anyone with it will know easily.

1: Diagnostic device 10: Sensor head 11: Printed circuit board 12: Through hole 13: Coupling groove 14: Hall sensor 15: Plate 16: Magnet 20: Moving cart 21: Case 22: Wheel 23: Handle 30: Signal processing control section 31 : Data logger 32: Display 34: Battery 100: Steel structure 101: Steel material 102: Welding part 103: Defect part

Claims (5)

A printed circuit board 11 in which a through hole 12 is formed at the center and a plurality of coupling grooves 13 are formed at a predetermined interval in a lower end thereof and a printed circuit board 11 fixedly coupled to the coupling groove 13, A flat plate type sensor head 10 having a sensor 14, a flat plate 15 inserted into the through hole 12, and a magnet 16 coupled to both lower ends of the plate 15;
A mobile carriage 20 having a case 21 in which the sensor head 10 is installed at a lower portion and a wheel 22 coupled to a side of the case 21 so as to rotate;
A data logger (31) installed in the mobile truck (20) and storing data collected by the sensor head (10);
And a signal processing control unit (30) for converting and processing the sensing signal inputted from the hall sensor (14) of the sensor head (10) and controlling the power applied to the sensor head (10) Device.
The apparatus according to claim 1, further comprising: a display (32) mounted on one side of the moving truck (20) to visually display an operating state; a handle (23) configured on the moving truck (20) And a battery (34) for supplying power necessary for operation of the installed components.
The steel structure safety diagnosis apparatus for a bridge according to claim 1, comprising an electric motor provided on the moving truck (20), and a controller for controlling the moving truck (20) remotely and wirelessly.
The apparatus of claim 1, wherein the Hall sensor (14) of the sensor head (10) is installed at a predetermined distance from the surface of the object to be sensed.
2. The method according to claim 1, wherein the magnetization direction of the hall sensor (14) is set in a direction diagonal to the traveling direction of the moving carriage (20) Steel structure safety diagnostic device.

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