Steel bridge deck top plate crack rapid scanning device capable of adjusting magnetic shielding

Abstract

The utility model is suitable for the technical field of nondestructive testing, and provides an adjustable magnetic shielding steel bridge deck top plate crack rapid scanning device which comprises a scanning trolley, a magnetic induction detection sensing part located in the middle and shielding covers located on the front side and the rear side are arranged in the scanning trolley. The magnetic induction detection sensing part is installed on the scanning trolley in an up-down adjustable mode, and the shielding cover is installed on the scanning trolley in an up-down and front-back adjustable mode. According to the utility model, a pair of shielding covers are adopted, so that background magnetic induction signals generated by the steel bridge body are conveniently deducted, and the detection accuracy is improved. In addition, the magnetic induction detection sensing part comprises a plurality of groups of sensing assemblies, so that the positioning precision of bridge floor top plate detection data is improved, and the millimeter-level positioning precision can be achieved in space. In addition, the movement track of the trolley is directly reflected through water dripping of the water tank, and stable operation of the trolley is facilitated. According to the technical scheme, the equipment cost is reduced, the operation efficiency is improved, and rapid and fine nondestructive detection scanning of the bridge deck top plate is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of nondestructive testing, and in particular relates to a steel bridge deck top plate crack fast scanning device with adjustable magnetic shielding. Background Art

[0002] The integrity detection of steel bridge deck is a very important and difficult research topic. First, the steel bridge deck is a direct supporting component for the vehicles passing on it, and its safety is directly related to the safety of the vehicles and the safety of society and economy. Secondly, the steel bridge deck is the most direct load-bearing component, which is directly rolled by the tires of the vehicles, and is the component that is most likely to produce stress concentration, fatigue damage, cracks and other defects. Thirdly, due to the special design of the steel bridge, the top plate of the steel bridge deck is particularly inconvenient to detect. If the inspection is directly on the steel bridge deck, there is often a laying layer on the top plate of the steel bridge deck, such as asphalt, high-performance concrete, etc. This laying layer is generally about 100mm thick, which greatly reduces the detection effect of various detection technologies. If the inspection is conducted under the bridge deck, because the steel box of the steel bridge is a confined space, the space below is limited, it is inconvenient to operate, and it is also inconvenient to locate, and the detection efficiency is low. Therefore, the bridge deck inspection of steel bridges has always been a very important and difficult research topic.

[0003] Currently, there is ultrasonic detection technology, but since the bridge deck is paved with asphalt, high-performance concrete and other materials, this greatly reduces the coupling efficiency of ultrasonic waves, thus limiting its detection performance. Electromagnetic detection technology is widely used in non-destructive testing, one of which is metal magnetic memory detection technology. The problem of detecting the top plate of the steel bridge deck has been around for a long time. The current conventional detection technologies, including ultrasonic detection technology, X-ray detection technology, penetration detection technology, eddy current detection technology, etc., are not convenient to carry out. The metal magnetic memory detection technology based on magnetic induction is to detect the magnetic signals generated and accumulated by ferromagnetic metals under the interaction of force and magnetism, and in turn evaluate the stress and fatigue of ferromagnetic metals. It has been increasingly used in recent years. Metal magnetic memory detection technology can detect stress concentration and cracks on the steel bridge deck through the laying layer of the steel bridge deck. However, metal magnetic memory detection technology is easily affected by the environmental magnetic field. At present, there is no way to deduct the environmental impact to achieve the evaluation of the local stress of ferromagnetic metals.

[0004] In addition, some technicians have proposed two solutions for rapid inspection of bridge deck top plates. One is to use a triangular trolley, install multiple high-speed data acquisition magnetic sensors side by side, and use people or vehicles to pull them to conduct rapid scanning and inspection on the bridge deck. This scanning method can indeed quickly achieve overall coverage scanning of the bridge deck, but its disadvantage is that it is not convenient to conduct further fine scanning for suspicious specific areas. The second is to use a scanning trolley equipped with a laser radar to conduct fine scanning of specific areas. This method can mainly achieve relatively fine scanning. However, its main limiting factor lies in the performance and life of the laser radar. At present, the price of a high-performance laser radar is about 100,000 yuan, and its spatial resolution is generally around 3 centimeters. For millimeter-level spatial resolution, current laser radar technology cannot achieve it. Utility Model Content

[0005] In view of the above problems, the purpose of the utility model is to provide a steel bridge deck top plate crack fast scanning device with adjustable magnetic shielding, aiming to solve the above technical problems.

[0006] The utility model adopts the following technical solutions:

[0007] A steel bridge deck top plate crack rapid scanning device with adjustable magnetic shielding comprises a scanning trolley, wherein the scanning trolley has a magnetic induction detection sensor part located in the middle and a shielding cover located at the front and rear sides, the magnetic induction detection sensor part is adjustable up and down and mounted to the scanning trolley, and the shielding cover is adjustable up and down and front and back and mounted to the scanning trolley.

[0008] Furthermore, the magnetic induction detection sensor part includes a frame bar, and a row of multiple sensor components are arranged at the bottom of the frame bar. The sensor components include three magnetic induction units of the same model arranged at the top, middle and bottom.

[0009] Furthermore, there is a positioning hole in the middle of the top of the scanning trolley, and adjustment slots at the front and back. There are adjustment rods on the top of the magnetic detection sensor part and the top of the shielding cover. The adjustment rods pass through the corresponding positioning holes or adjustment slots and are locked with a pair of nuts.

[0010] Furthermore, a water tank is fixed on the scanning trolley, and the water tank is connected to a dripping pipe, and the water outlet of the dripping pipe is close to the bottom of the trolley.

[0011] Furthermore, the scanning trolley has four small wheels, a bracket is installed on the back of the scanning trolley, an electronic system is installed on the bracket, and a pair of handles are formed at the end of the bracket.

[0012] The beneficial effects of the utility model are as follows: the device of the utility model is pushed on the bridge deck in the form of a trolley, and is easy to operate; the trolley is provided with a magnetic induction detection sensor part and a pair of front and rear shielding covers, which are convenient for deducting the background magnetic induction signal generated by the steel bridge body itself, realizing the detection and deduction of the environmental magnetic field, and improving the accuracy of the magnetic induction data of the bridge deck top plate and the accuracy of the detection. In addition, the magnetic induction detection sensor part includes a plurality of sensor components, and the sensor components include magnetic induction units arranged at the top, middle and bottom, which improves the positioning accuracy of the bridge deck top plate detection data, and can achieve millimeter-level positioning accuracy in space. In addition, the movement trajectory of the trolley can be intuitively seen through the dripping of water from the water tank, which is convenient for stable operation of the trolley. The technical solution of the utility model reduces equipment costs, improves operating efficiency, and realizes rapid, precise non-destructive detection scanning of the bridge deck top plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a three-dimensional diagram of a scanning device provided by an embodiment of the utility model;

[0014] Figure 2 It is a bottom view of the scanning device provided by an embodiment of the utility model;

[0015] Figure 3 It is a positional relationship diagram of the magnetic induction detection sensor part and the shielding cover;

[0016] Figure 4 It is a structural diagram of the magnetic induction detection sensor unit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0018] In order to illustrate the technical solution of the present invention, specific embodiments are provided below for illustration.

[0019] like Figure 1-3 As shown, the steel bridge deck top plate crack rapid scanning device with adjustable magnetic shielding provided in this embodiment includes a scanning trolley 1, wherein the scanning trolley 1 has a magnetic detection sensor part 2 located in the middle, and a shielding cover 3 located at the front and rear sides, the magnetic detection sensor part 2 is adjustably mounted to the scanning trolley 1 up and down, and the shielding cover 3 is adjustably mounted to the scanning trolley 1 up and down, front and back.

[0020] The problem of steel bridge deck top plate detection has been around for a long time. The current conventional detection technologies, including ultrasonic detection technology, X-ray detection technology, penetration detection technology, eddy current detection technology, etc., are not convenient to carry out. The metal magnetic memory detection technology based on magnetic induction can detect stress concentration and cracks on the steel bridge deck through the laying layer of the steel bridge deck. The metal magnetic memory detection technology uses magnetic sensors to record the parallel and vertical magnetic induction signals on the surface of ferromagnetic metal parts. Then, through the principle of force-magnetic interaction, in turn, the stress concentration and possible cracks of the component itself are judged by the magnetic induction signals on the surface of the ferromagnetic metal component. This magnetic induction detection technology cannot achieve accurate quantitative detection of stress concentration and cracks, but it is very suitable as a fast scanning technology to quickly scan large-area targets to greatly reduce the scope that needs further detection.

[0021] However, when conventional metal magnetic memory detection is directly applied to steel bridge body detection, the background magnetic induction signal generated by the steel bridge body itself will affect the detection result. For this reason, in this embodiment, an adjustable shielding cover and a magnetic induction detection sensor are used to conveniently deduct the background magnetic induction signal generated by the steel bridge body itself and improve the accuracy of the detection. In addition, the entire scanning device adopts a trolley form to facilitate operation and more easily record the movement of the scanning device.

[0022] The magnetic induction detection sensor is the core part of the magnetic induction detection of the scanning device. As a specific structure, Figure 4 As shown, the magnetic induction detection sensor part 2 includes a frame bar 21, and a row of multiple sensor components 22 are arranged at the bottom of the frame bar 21. The sensor component 22 includes three magnetic induction units of the same model arranged at the top, middle and bottom. The magnetic induction unit is a highly sensitive three-dimensional magnetic sensor, which can be a precision three-dimensional coil or a three-dimensional magnetic sensor chip. The figure uses eight groups of sensor components, each of which uses three magnetic induction units of the same model at the top, middle and bottom, and the magnetic induction units of the same performance are used as the core of the detection. The three magnetic induction units are arranged at equal distances, and the magnetic induction unit at the bottom layer is about 20 mm away from the ground, as close to the ground as possible while avoiding touching the debris on the ground. The magnetic induction unit in the middle is about 50 mm away from the ground, and the sensor at the top layer is about 80 mm away from the ground. And when installing the magnetic induction unit, try to ensure that its X-axis, Y-axis and Z-axis are parallel or coincident with the X-axis, Y-axis and Z-axis of the trolley, the Y-axis is the forward and backward movement direction of the scanning device, and the vertical direction is the Z-axis.

[0023] Three vertically arranged magnetic sensing units form a group. Under the shielding effect of the front and rear shielding covers, the environmental magnetic field can be deducted. These two adjustable shielding covers have two key parameters that can be adjusted: ground clearance and front and rear width. The ground clearance is the distance from the bottom of the shielding cover to the ground, and the front and rear width is the distance from the shielding cover to the magnetic induction detection sensor. In general, the front and rear width can be adjusted, but the front and rear widths must be kept the same.

[0024] The shielding effect principle of the shielding cover is as follows:

[0025] The Ohm's law of magnetic circuit can be used to evaluate the magnetic field detected by the scanning device of this embodiment. For the background magnetic field generated by the steel bridge, the relationship between the magnetic flux, magnetomotive force and magnetic resistance in the magnetic circuit can be expressed as:

[0026] Φ=F / Rm

[0027] Where Φ is the magnetic flux passing through the scanning device, in Weber; F is the magnetomotive force of these magnetic fluxes, in ampere-turns; Rm is the magnetic resistance of the magnetic circuit in a specific direction, in ampere-turns per Weber. The relative magnetic permeability of air is about 1, while for magnetic materials with good performance, the relative magnetic permeability can reach several thousand, and the magnetic resistance is small, so the magnetic flux of the background magnetic field is more likely to pass through this path, thereby shielding the background magnetic field.

[0028] The front and rear shields constitute the detection area. Because the influence of the background magnetic field is reduced, the magnetic memory signal is dominant and is easier to be detected by multiple sets of magnetic sensing components. At the same time, because the front and rear shields can adjust the upper and lower heights and the front and rear distances, the detection area can be adjusted. This adjustment is suitable for the sensitivity adjustment of stress in steel bridge decks with different laying layer thicknesses and different size areas, so as to achieve targeted detection.

[0029] As a specific regulatory structure, combined Figure 1-3 As shown, the scanning trolley 1 has a positioning hole 11 in the middle of the top, and adjustment slots 12 at the front and back. The top of the magnetic induction sensor and the top of the shielding cover are both provided with adjustment rods 13, and the adjustment rods 13 are passed through the corresponding positioning holes 11 or adjustment slots 12 and then locked with a pair of nuts 14. When installing, first adjust the height of the lower nut, then pass the adjustment rod through the corresponding positioning hole or adjustment slot, and lock it with the upper nut. The height adjustment and front and rear distance adjustment methods are simple.

[0030] The detection trolley is the main body of the scanning device. The detection trolley 1 has four small wheels 15, at least one of which is a coding wheel to record the travel distance of the trolley. A bracket 5 is installed on the back of the scanning trolley 1, and an electronic system 51 is installed on the bracket 5. The end of the bracket 5 is a pair of handles 52. The handles can be pushed manually to easily push the trolley forward and backward. The electronic system 51 is the nerve center of the scanning device. A tablet computer, microcomputer, or laptop computer can be used as the host. In addition to the host, a high-performance data acquisition card and power supply are also required. The data acquisition card converts the signals of each magnetic induction component and the coding wheel into digital signals and sends them to the host of the system. The power supply provides energy for the system.

[0031] A water tank 41 is also fixed on the scanning trolley 1, and the water tank 41 is connected to a dripping pipe 42. The water outlet of the dripping pipe 42 is close to the bottom of the trolley, and the liquid stored in the water tank can be dripped downward as a mark of the movement (scanning) track of the scanning device. By observing the track of the liquid and referring to the track on the host display screen, the inspector can more accurately grasp the extent of track coverage.

[0032] The specific operation process is as follows: After the inspector records the necessary information, he places the scanning device at the starting position of a specific area of ​​the steel bridge deck, and adjusts the height and width of the front and rear shielding covers according to the thickness of the laying layer. A value that can be used for on-site reference is: the width from the front and rear shielding covers to the center of the magnetic induction detection sensor part is twice the thickness of the bridge deck laying layer; then turn on the water tank switch to start dripping water and record the trajectory; at the same time, push the scanning device forward steadily along the Y direction. When the scanning device reaches the extreme end of the Y direction, the trolley moves a small distance to the right, such as 5mm, and then scans in the -Y direction at a uniform and stable speed. When the scanning device reaches the extreme end of the -Y direction, the scanning device continues to move a small distance to the right, and then scans in the Y direction at a uniform and stable speed. Repeat this process to complete the scanning of the entire specific area. The scanning device of the utility model improves the detection space resolution, and improves the centimeter-level resolution of the existing magnetic induction detection technology to the millimeter-level resolution.

[0033] In summary, the utility model discloses a fast scanning device for cracks on the top plate of a steel bridge deck with adjustable magnetic shielding, which can deduct the background magnetic field generated by the huge volume of the steel bridge and realize the local magnetic memory signal detection and stress condition assessment of the steel bridge deck. On this basis, an environmentally friendly data recording scheme of a coding wheel and a water droplet trajectory is adopted to realize the precise positioning of the steel bridge deck, further improving the accuracy of magnetic induction detection.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fast scanning device for cracks on the top plate of a steel bridge deck with adjustable magnetic shielding, characterized in that: The scanning device includes a scanning trolley, which has a magnetic detection sensor located in the middle and a shielding cover located on the front and rear sides. The magnetic detection sensor can be adjusted up and down and installed on the scanning trolley, and the shielding cover can be adjusted up and down and front and back and installed on the scanning trolley.

2. The steel bridge deck top plate crack rapid scanning device with adjustable magnetic shielding as claimed in claim 1, characterized in that: The magnetic induction detection sensor part includes a frame bar, and a row of sensor components with a total of multiple groups are arranged at the bottom of the frame bar. The sensor components include three magnetic induction units of the same model arranged at the top, middle and bottom.

3. The steel bridge deck top plate crack fast scanning device with adjustable magnetic shielding as claimed in claim 2 is characterized in that: There is a positioning hole in the middle of the top of the scanning trolley, and adjustment slots at the front and back. There are adjustment rods on the top of the magnetic detection sensor part and the top of the shielding cover. The adjustment rods pass through the corresponding positioning holes or adjustment slots and are locked with a pair of nuts.

4. The steel bridge deck top plate crack fast scanning device with adjustable magnetic shielding according to any one of claims 1 to 3, characterized in that: A water tank is also fixed on the scanning trolley, and the water tank is connected to a dripping pipe, and the water outlet of the dripping pipe is close to the bottom of the trolley.

5. The steel bridge deck top plate crack fast scanning device with adjustable magnetic shielding as claimed in claim 4 is characterized in that: The scanning trolley has four small wheels. A bracket is installed on the back of the scanning trolley. The bracket has an electronic system and a pair of handles at the end of the bracket.

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