Bridge bearing capacity dynamic load test detection device

Abstract

The application relates to the technical field of bridge load experiment, in particular to a bridge bearing capacity dynamic load experiment detection device. The top end of a supporting frame is fixedly connected with a photosensitive assembly and a first laser range finder. A heavy-load vehicle is provided with a reflector plate, the first laser range finder is horizontal to the reflector plate, the first laser range finder can measure the horizontal distance a from the center of the hub in the tire through the reflector plate, the front and rear hubs of the heavy-load vehicle are both provided with positioning plates through bolts, one end of each positioning plate is fixedly connected with a connecting shaft, the outer side of the connecting shaft is rotatably connected with first shaft sleeves through bearings, and the two first shaft sleeves are connected with an extension rod. The monitoring mode can avoid installing sensors at various positions of the bridge, saves the equipment and the installation amount, and can realize continuous deflection monitoring. In the application, the axle height curve obtained when the heavy-load vehicle advances is compared with the axle height curve obtained when the heavy-load vehicle advances without load.

Description

Technical Field

[0001] This invention relates to the field of bridge load testing technology, specifically to a dynamic load testing device for bridge bearing capacity. Background Technology

[0002] As bridges age, all bridges will eventually enter a period of aging and maintenance, resulting in a huge workload for inspection and evaluation.

[0003] Currently, static load testing is a relatively mature method for assessing the load-bearing capacity of bridges. However, it should be noted that a complete static load test is time-consuming and labor-intensive, requiring the bridge to be closed off. Furthermore, because the load level in the static load test is based on the design load requirements, it may cause irreversible secondary damage to bridges that have been in service for a long time.

[0004] Dynamic loads represent the load form of a bridge under normal service conditions. Compared with static load tests, dynamic load tests provide deterministic load excitation while also having obvious advantages such as economy and efficiency.

[0005] In the prior art, when conducting dynamic load tests, a large number of sensors need to be deployed at various locations on the bridge. The sensors at different locations also need to be calibrated and communicate with each other. The present invention provides a solution for vehicle-mounted sensors, which can greatly simplify the number of sensors used and the steps for installing sensors on the bridge.

[0006] When a heavy-duty vehicle moves on a bridge, the vehicle's weight is transferred to the wheel hubs and tires through the suspension system. If the sensor is mounted directly on the vehicle body, the actual vertical change of the vehicle body in the dynamic load test will be lagging and inaccurate due to the presence of the suspension system. If the sensor is mounted on the wheel hub, the rotation of the wheel hub will bring new problems to the sensor installation. Moreover, since the tire itself is also an elastic component, the contact area between the tire and the ground will still change during the vehicle's acceleration and deceleration, causing the sensor to show a change in vertical height. Summary of the Invention

[0007] The purpose of this invention is to provide a dynamic load testing device for bridge bearing capacity. By installing sensors on the wheel hub, this invention can achieve high-frequency data acquisition by utilizing the wheel's rotation, while minimizing uncontrollable factors and timely and effectively compensating for measurement errors caused by the vehicle's forward and backward tilt and acceleration changes, thus achieving accurate and efficient measurement.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a dynamic load test device for bridge bearing capacity, comprising a heavy-duty vehicle and a support frame, wherein a photosensitive component and a first laser rangefinder are fixedly connected to the top of the support frame, a reflector is provided on the heavy-duty vehicle, the first laser rangefinder is horizontal with the reflector, and the first laser rangefinder can measure the horizontal distance 'a' between itself and the center of the inner wheel hub of the tire through the reflector.

[0009] The front and rear wheel hubs of the heavy-duty vehicle are bolted with positioning plates. The positioning plates are concentric with the wheel hubs. One end of the positioning plate is fixedly connected to a connecting shaft. The outer side of the connecting shaft is rotatably connected to a first bushing through a bearing. A telescopic rod is connected between the two first bushings.

[0010] In this invention, coaxial connecting shafts are installed on two hubs respectively, and first bushings are fitted onto the two connecting shafts. A telescopic rod connects the two first bushings. This arrangement prevents the first bushings from rotating with the connecting shafts, allowing the connecting shafts to serve as a mounting platform for subsequent monitoring components. When installing the positioning plates, it is necessary to ensure that the two positioning plates are flush and the telescopic rod is horizontal, and that the extension line of the telescopic rod passes through the center of the connecting shaft.

[0011] A connecting rod is fixedly connected to the bottom end of the first bushing, and a fourth bushing is fixedly connected to the other end of the connecting rod. An acceleration shaft is rotatably connected to the inner side of the fourth bushing. The acceleration shaft is concentric with the hub and is connected to the connecting shaft through an acceleration assembly. A laser emitter is fixedly connected to the end of the acceleration shaft. The laser emitter accelerates as the hub rotates. An angle sensor is fixedly connected to the inner side of the fourth bushing to obtain the angle of the laser emitter. Every time the laser emitter rotates, a beam of light is captured by the photosensitive assembly. The angle d relative to the ground at the time of capture is obtained, and the real-time height b of the connecting shaft is calculated using trigonometric functions.

[0012] When this invention is in operation, starting from the bridge pier, a heavy-duty vehicle travels along a fixed straight line on the bridge. During the travel, because the axle is the load point of the heavy-duty vehicle, the weight at the axle may cause the bridge to deflect. This invention can monitor the change in axle height during the movement of the heavy-duty vehicle, thereby reflecting the change in the lateral position of the bridge following the deflection at the axle in the dynamic load test, and realizing the evaluation of the bridge.

[0013] The method for monitoring changes in axle height in this invention is as follows:

[0014] 1. Because the horizontal distance between the reflector and the center of the axle is fixed, the first laser rangefinder can measure the horizontal distance 'a' between the reflector and the center of the inner wheel hub of the tire. The reflector is a diffuse reflector. The measuring range of the first laser rangefinder is 0-3km. It is an industrial laser rangefinder and is existing technology. It will not be elaborated further.

[0015] 2. When a heavy-duty vehicle moves horizontally, a beam of light is captured by the photosensitive component every time the laser emitter at the axle rotates. The angle d of the captured laser emitter relative to the ground is obtained by the angle sensor, and the real-time height b of the connecting axle is calculated by trigonometric functions to realize the monitoring of the axle height. Ignoring the change in axle height due to the extension and contraction of the tires, the change in axle height reflects the change in bridge deflection at the axle. The angle sensor is selected as a Hall angle sensor or a potentiometer-type angle sensor.

[0016] 3. Because a heavy-duty vehicle may move several meters forward with each rotation of the tire, this invention can use the rotation of the wheel and the acceleration component to accelerate the rotation of the laser emitter, so that the laser emitter can rotate hundreds of times or even more with each rotation of the tire, thereby achieving high-frequency acquisition and continuous axle height monitoring, that is, monitoring the change of bridge deflection at the dynamic axle.

[0017] This monitoring method avoids installing sensors at various locations on the bridge, saving equipment and installation costs, and enables continuous deflection monitoring.

[0018] In this invention, the axle height curve obtained when the vehicle is moving forward under heavy load is compared with the axle height curve obtained when the vehicle is moving forward without load. By gradually increasing the load and referring to the changes in the axle height curve, the load-bearing capacity of the bridge can be monitored.

[0019] In a preferred embodiment of the dynamic load testing device for bridge bearing capacity of the present invention, a connecting pipe is fixedly connected to one side of each of the two first bushings, and a telescopic rod is detachably connected between the two connecting pipes by means of a threaded connection. A single-axis dynamic tilt sensor is fixedly connected to one side of the telescopic rod, and the telescopic rod is used to perform the function of expansion and contraction compensation.

[0020] The connecting pipe is introduced to make the telescopic rod easy to assemble and disassemble;

[0021] Because of the presence of multiple axles in a vehicle, when the heights of the front and rear axles of a heavy-duty vehicle are inconsistent, the telescopic rod will tilt. That is, when the normal line perpendicular to the telescopic rod does not coincide with the vertical line, the first axle sleeve that supports the platform will also tilt, and the initial detection position of the angle sensor will also rotate. Since the angle d required for monitoring the axle height is relative to the ground and is an absolute angle, compensation is required. The single-axis dynamic tilt sensor set in this invention can obtain the tilt angle at this time, and then correct and compensate the laser emitter angle detected by the angle sensor according to the angle. When the angle sensor deflects counterclockwise, clockwise compensation is required. The single-axis dynamic tilt sensor is a dynamic tilt detector that can realize tilt detection in motion. It is existing technology and will not be elaborated further here.

[0022] Preferably, in this invention, a dynamic load testing device for bridge bearing capacity is provided, in which a first gear is fixedly connected to the end of the connecting shaft, a fourth gear is fixedly connected to the outer side of the acceleration shaft, a third sleeve is fixedly connected to the top of the first sleeve, a second sleeve is fixedly connected to the top of the fourth sleeve, and a second gear and a third gear are coaxially rotatably connected to the inner sides of the third sleeve and the second sleeve. The diameter of the third gear is larger than that of the second gear. The second gear meshes with the first gear, and the diameter of the second gear is smaller than that of the first gear. The third gear meshes with the fourth gear, and the diameter of the fourth gear is smaller than that of the third gear. By utilizing the rotation of the hub when it moves forward and the speed-increasing effect between the gears, the high-speed rotation of the laser emitter is achieved, thereby increasing the sampling frequency.

[0023] Under the above settings, the speed is increased by the meshing of the large gear and the small gear, thereby increasing the sampling frequency;

[0024] Preferably, in the bridge bearing capacity dynamic load test device of the present invention, the reflector is fixedly installed on the side of the first bushing facing the first laser rangefinder or directly above the heavy-duty vehicle.

[0025] The reflector should be positioned close to the connecting shaft and the center of rotation. This will ensure that the lateral offset of the reflector is small enough to be negligible when the heavy vehicle tilts forward or backward. The reflector should also have sufficient vertical height to ensure that the first laser rangefinder can always measure the distance to the reflector.

[0026] Preferably, in the bridge bearing capacity dynamic load test device of the present invention, a rotating block is embedded in the inner side of the acceleration shaft, the rotating block is slidably connected to the inner side of the angle sensor, the azimuth angle of the rotating block and the laser emitter on the acceleration shaft are consistent, and the azimuth angle of the laser emitter is obtained by obtaining the azimuth angle of the rotating block.

[0027] Preferably, in the bridge bearing capacity dynamic load test device of the present invention, a turntable is fixedly connected to the end of the acceleration shaft, a laser emitter is fixed inside the turntable, and a counterweight is fixedly connected to a position symmetrical to the laser emitter inside the turntable to reduce vibration during rotation.

[0028] As a preferred embodiment of the dynamic load testing device for bridge bearing capacity according to the present invention, the photosensitive component includes an optical fiber at the front end and a photosensitive sensor at the rear end. The photosensitive sensor is a photoresistor, etc. The optical fiber diverges horizontally forward and gradually converges at the end. The optical fiber can realize non-linear propagation of light and concentrate the light at the tail. The sensing end of the photosensitive sensor is located at the end of the optical fiber. After the optical fiber emitted by the laser emitter passes through the optical fiber, it will be conducted to the end and sensed by the photosensitive sensor.

[0029] Preferably, in the bridge bearing capacity dynamic load test device of the present invention, a rotating ring is rotatably connected to the outer side of the first bushing, a vertical rod is fixedly connected to the bottom end of the rotating ring, and a second laser rangefinder is fixedly connected to the bottom end of the vertical rod, with the second laser rangefinder facing the lower side of the tire.

[0030] In a preferred embodiment of the dynamic load testing device for bridge bearing capacity according to the present invention, the side of the tire facing the second laser rangefinder is coated with a reflective ring. After the second laser rangefinder irradiates the reflective ring, it infers the height change of the tire caused by elastic deformation based on the width change of the bottom of the tire, thereby compensating for the change.

[0031] When a heavily loaded vehicle accelerates or decelerates, the height of the tire bottom changes due to the increase and decrease in load. Figure 12 For example, when decelerating, the load on the front axle increases, and the axle center will lower;

[0032] The bottom width of the tire can reflect the change in the height of the tire bottom at this time. This invention uses a second laser rangefinder at a fixed position to detect the width of the tire bottom position, thereby obtaining the value of the change in the height of the tire bottom, so as to achieve compensation when calculating the dynamic deflection of the bridge.

[0033] The mapping relationship between tire bottom width and tire bottom height needs to be established through experiments in advance.

[0034] Preferably, in the bridge bearing capacity dynamic load test device of the present invention, a motor is fixedly connected to the outer side of the first bushing, a drive gear is fixedly connected to the end of the motor's main shaft, a half-tooth ring is fixedly connected to the rotating ring on one side of the motor, and the drive gear meshes with the half-tooth ring. Referring to a single-axis dynamic tilt sensor, it is used to compensate for the change in the vertical rod angle caused by the inconsistent height of the front and rear axles of a heavy-duty vehicle.

[0035] The motor is a self-locking motor. When the motor is not working, the rotating ring rotates synchronously with the first bushing. When the telescopic rod is tilted, the motor drives the gear and the half-tooth ring to rotate the vertical rod to achieve angle compensation, based on the tilt value obtained by the single-axis dynamic tilt sensor, so as to ensure that the position of the second laser rangefinder is fixed relative to the bottom of the tire.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] 1. A dynamic load test device for bridge bearing capacity. When the invention is working, starting from the bridge pier, a heavy-duty vehicle travels along a fixed straight line on the bridge. During the travel, because the axle is the load point of the heavy-duty vehicle, the weight at the axle may cause the bridge to deflect. The invention can monitor the change in axle height during the movement of the heavy-duty vehicle, thereby reflecting the change in the lateral position of the bridge following the deflection at the axle in the dynamic load test, and realizing the evaluation of the bridge.

[0038] 2. This dynamic load testing device for bridge bearing capacity utilizes a fixed horizontal distance between the reflector and the axle center. A first laser rangefinder measures the horizontal distance 'a' between the reflector and the center of the inner wheel hub. The reflector is a diffuse reflector. When a heavy-duty vehicle moves horizontally, a beam of light is captured by the photosensitive component for each rotation of the laser emitter at the axle. The angle 'd' of the captured laser emitter relative to the ground is obtained through an angle sensor, and the real-time height 'b' of the connecting axle is calculated using trigonometric functions, thus enabling axle height monitoring. Since a heavy-duty vehicle may move several meters per tire rotation, this invention utilizes the wheel's rotation and an acceleration component to accelerate the laser emitter's rotation. This allows the laser emitter to rotate hundreds of times or even more per tire rotation, achieving high-frequency data acquisition and continuous axle height monitoring, i.e., monitoring changes in bridge deflection at the dynamic axle.

[0039] 3. This dynamic load testing device for bridge bearing capacity avoids the need to install sensors at various locations on the bridge, saving equipment and installation costs, and enables continuous deflection monitoring.

[0040] 4. The dynamic load test device for bridge bearing capacity of this invention compares the axle height curve obtained when the vehicle is moving forward under heavy load with the axle height curve obtained when the vehicle is moving forward without load, and gradually increases the load and refers to the change of the axle height curve, so as to realize the monitoring of the bridge bearing capacity.

[0041] 5. In this dynamic load testing device for bridge bearing capacity, due to the presence of multiple axles on a vehicle, when the heights of the front and rear axles of a heavily loaded vehicle are inconsistent, the telescopic rod will tilt, that is, when the normal line perpendicular to the telescopic rod does not coincide with the plumb line, the first axle sleeve that serves as the support platform will also tilt, and the initial detection position of the angle sensor will also rotate. Since the angle d required for monitoring the axle height is relative to the ground and is an absolute angle, compensation is required. The single-axis dynamic tilt sensor set in this invention can obtain the tilt angle at this time, and then correct and compensate the laser emitter angle detected by the angle sensor according to the angle. When the angle sensor deflects counterclockwise, clockwise compensation is required.

[0042] 6. This dynamic load testing device for bridge bearing capacity addresses the issue that when a heavy-duty vehicle accelerates or decelerates, the tire bottom will experience height changes due to the increase or decrease in load. For example, during deceleration, the front axle load increases, and the axle center will lower. The tire bottom width reflects the height change of the tire axle center at this time. This invention uses a second laser rangefinder at a fixed position to detect the width of the tire bottom position, thereby obtaining the height change value of the tire bottom, and thus achieving compensation when calculating the dynamic deflection of the bridge. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the external structure of the present invention when it is installed at the wheel hub;

[0044] Figure 2 This is a schematic diagram of the detection experiment of the present invention;

[0045] Figure 3 This is a schematic diagram of the structure of the present invention after modification on a heavy-duty vehicle;

[0046] Figure 4 This is a further side view of the hub structure of the present invention;

[0047] Figure 5 For the present invention Figure 4 A schematic diagram of the structure at point C;

[0048] Figure 6 For the present invention Figure 4 A schematic diagram of the structure at point D;

[0049] Figure 7 This is a schematic diagram of the structure of the reflective strip on the side of the tire according to the present invention;

[0050] Figure 8 This is a schematic diagram of the installation structure of the angle sensor inside the sleeve of the present invention;

[0051] Figure 9 This is a schematic diagram of the structure of the angle sensor when the axles of the front and rear tires of the heavy-duty vehicle are horizontal and there is a height difference, and when the angle sensor is initially positioned and when it shifts.

[0052] Figure 10 A schematic diagram showing the elevation of the bridge surface where the wheel hub is located during the moving load experiment of this invention.

[0053] Figure 11 This is a schematic diagram of the internal structure of the laser receiver of the present invention;

[0054] Figure 12 This is a schematic diagram of the elevation curve of the bridge surface as it moves with dynamic load, obtained by the present invention.

[0055] Figure 13 This is a diagram illustrating the changes at the bottom of the tires when a heavily loaded vehicle decelerates.

[0056] In the diagram: 1. Pier; 2. Bridge; 3. Support frame; 4. Photosensitive component; 5. First laser rangefinder; 6. Heavy-duty vehicle; 7. Reflector; 8. Tire; 9. First axle sleeve; 10. Connecting pipe; 11. Telescopic rod; 12. Second axle sleeve; 13. First gear; 14. Second gear; 15. Third gear; 16. Turntable; 17. Connecting rod; 18. Positioning plate; 19. Third axle sleeve; 20. Reflector ring; 21. Fourth axle 21. Set; 22. Angle sensor; 23. Acceleration shaft; 24. Single-axis dynamic tilt sensor; 25. Rotating block; 26. Vertical line; 27. Normal line perpendicular to the telescopic rod; 28. Vertical rod; 29. ​​Second laser rangefinder; 30. Counterweight; 31. Laser emitter; 32. Fourth gear; 33. Optical fiber; 34. Photosensor; 35. Motor; 36. Rotary ring; 37. Drive gear; 38. Half-tooth ring; 39. Connecting shaft. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Example 1, please refer to Figure 1-13 The present invention provides a technical solution, a dynamic load test and detection device for bridge bearing capacity, including a heavy-duty vehicle 6 and a support frame 3. A photosensitive component 4 and a first laser rangefinder 5 are fixedly connected to the top of the support frame 3. A reflector 7 is provided on the heavy-duty vehicle 6. The first laser rangefinder 5 is horizontal with the reflector 7. The first laser rangefinder 5 can measure the horizontal distance a between itself and the center of the inner wheel hub of the tire 8 through the reflector 7.

[0059] The front and rear wheel hubs of the heavy-duty vehicle 6 are both bolted with positioning plates 18. The positioning plates 18 are concentric with the wheel hubs. One end of the positioning plate 18 is fixedly connected to a connecting shaft 39. The outer side of the connecting shaft 39 is rotatably connected to a first bushing 9 through a bearing. A telescopic rod 11 is connected between the two first bushings 9.

[0060] In this invention, coaxial connecting shafts 39 are installed on two hubs respectively, and first bushings 9 are fitted onto the two connecting shafts 39. A telescopic rod 11 is connected between the two first bushings 9. This arrangement can prevent the first bushings 9 from rotating with the connecting shafts 39, so that the connecting shafts 39 can serve as a mounting platform for subsequent monitoring components. When installing the positioning plates 18, it is necessary to ensure that the two positioning plates 18 are flush and the telescopic rod 11 is horizontal, and that the extension line of the telescopic rod 11 can pass through the center of the connecting shafts 39.

[0061] A connecting rod 17 is fixedly connected to the bottom end of the first bushing 9, and a fourth bushing 21 is fixedly connected to the other end of the connecting rod 17. An acceleration shaft 23 is rotatably connected to the inner side of the fourth bushing 21. The acceleration shaft 23 is concentric with the hub. The acceleration shaft 23 is connected to the connecting shaft 39 through an acceleration assembly. A laser emitter 31 is fixedly connected to the end of the acceleration shaft 23. The laser emitter 31 accelerates as the hub rotates. An angle sensor 22 is fixedly connected to the inner side of the fourth bushing 21 to obtain the angle of the laser emitter 31. Every time the laser emitter 31 rotates, a beam of light is captured by the photosensitive assembly 4. The angle d of the laser emitter 31 relative to the ground at the time of capture is obtained, and the real-time height b of the connecting shaft 39 is calculated by trigonometric functions.

[0062] In this invention, the axle and the hub center have the same meaning. When this invention is working, starting from the bridge pier, the heavy-duty vehicle 6 travels along a fixed straight line on the bridge 2. During the travel, because the axle is the load point of the heavy-duty vehicle 6, the weight at the axle may cause the bridge 2 to deflect. This invention can monitor the change in axle height during the forward movement of the heavy-duty vehicle 6, thereby reflecting the change in the lateral position of the bridge 2 following the deflection at the axle in the dynamic load test, and realizing the evaluation of the bridge.

[0063] The method for monitoring changes in axle height in this invention is as follows:

[0064] 1. Because the horizontal distance between the reflector 7 and the center of the axle is fixed, the first laser rangefinder 5 can measure the horizontal distance a between the reflector 7 and the center of the axle of the inner wheel hub of the tire 8 through the reflector 7. The reflector 7 is a diffuse reflector. The measuring range of the first laser rangefinder 5 is 0-3km. It is an industrial laser rangefinder with millimeter-level accuracy. It is existing technology and will not be elaborated further here.

[0065] 2. When the heavy-duty vehicle 6 moves forward horizontally, a beam of light is captured by the photosensitive component 4 for each rotation of the laser emitter 31 at the axle. The angle sensor 22 obtains the angle d of the captured laser emitter 31 relative to the ground, and then calculates the real-time height b of the connecting shaft 39 through trigonometric functions to realize the monitoring of the axle height. Ignoring the change in axle height due to the extension and retraction of the bottom of the tire 8, the change in axle height as the axle moves reflects the change in the deflection of the bridge under the axle. The angle sensor 22 is selected as a Hall angle sensor or a potentiometer-type angle sensor.

[0066] 3. Because the heavy-duty vehicle 6 may move forward several meters for every rotation of the tire 8, the present invention can use the rotation of the wheel and the acceleration component to accelerate the rotation of the laser emitter 31, so that for every rotation of the tire 8, the laser emitter 31 can rotate hundreds of times or even more, thereby achieving high-frequency acquisition and continuous axle height monitoring, that is, monitoring the change of bridge deflection at the dynamic axle.

[0067] This monitoring method avoids installing sensors at various locations on the bridge, saving equipment and installation costs, and enables continuous deflection monitoring.

[0068] In this invention, the axle height curve obtained when the vehicle is moving forward under heavy load is compared with the axle height curve obtained when the vehicle is moving forward without load. By gradually increasing the load and referring to the changes in the axle height curve, the load-bearing capacity of the bridge can be monitored.

[0069] Specifically, each of the two first bushings 9 is fixedly connected to a connecting pipe 10 on one side. The two connecting pipes 10 are detachably connected to a telescopic rod 11 by means of a threaded connection. A single-axis dynamic tilt sensor 24 is fixedly connected to one side of the telescopic rod 11. The telescopic rod 11 is used to perform telescopic compensation.

[0070] The connecting pipe 10 is introduced to make the telescopic rod 11 easy to assemble and disassemble;

[0071] Because of the presence of multiple axles on a vehicle, when the heights of the front and rear axles of a heavy-duty vehicle are inconsistent, the telescopic boom 11 will tilt, such as... Figure 9 When the normal 27 perpendicular to the telescopic rod does not coincide with the plumb line 26, the first bushing 9, which serves as the support platform, will also tilt, and the initial detection position of the angle sensor 22 will also rotate. Since the angle d required for monitoring the axle height is relative to the ground and is an absolute angle, compensation is required. The single-axis dynamic tilt sensor 24 set in this invention can obtain the tilt angle at this time, and then correct and compensate the angle of the laser emitter 31 detected by the angle sensor 22 according to the angle. When the angle sensor 22 deflects counterclockwise, clockwise compensation is required. The single-axis dynamic tilt sensor 24 is a dynamic tilt detector that can realize tilt detection in motion. It is existing technology and will not be elaborated further here.

[0072] Specifically, a first gear 13 is fixedly connected to the end of the connecting shaft 39, a fourth gear 32 is fixedly connected to the outer side of the acceleration shaft 23, a third bushing 19 is fixedly connected to the top of the first bushing 9, a second bushing 12 is fixedly connected to the top of the fourth bushing 21, and a second gear 14 and a third gear 15 are coaxially rotatably connected to the inner sides of the third bushing 19 and the second bushing 12. The diameter of the third gear 15 is larger than that of the second gear 14. The second gear 14 meshes with the first gear 13, and the diameter of the second gear 14 is smaller than that of the first gear 13. The third gear 15 meshes with the fourth gear 32, and the diameter of the fourth gear 32 is smaller than that of the third gear 15. By utilizing the rotation of the hub when it moves forward and the speed-increasing effect between the gears, the high-speed rotation of the laser emitter 31 is achieved, thereby increasing the sampling frequency.

[0073] Under the above settings, the speed is increased by the meshing of the large gear and the small gear, thereby increasing the sampling frequency;

[0074] Specifically, the reflector 7 is fixedly installed on the side of the first bushing 9 facing the first laser rangefinder 5 or directly above the heavy-duty vehicle 6.

[0075] The reflector 7 should be positioned close to the connecting shaft 39 (e.g., the side of the first bushing 9 facing the first laser rangefinder 5) and close to the rotation center. This way, when the heavy-duty vehicle 6 tilts slightly forward or backward, the lateral horizontal offset of the reflector 7 will be small enough to be ignored. The reflector 7 has sufficient vertical height to ensure that the first laser rangefinder 5 can always measure the distance of the reflector 7.

[0076] Specifically, a rotating block 25 is embedded in the inner side of the acceleration shaft 23. The rotating block 25 is slidably connected to the inner side of the angle sensor 22. The azimuth angle of the rotating block 25 and the laser emitter 31 on the acceleration shaft 23 are consistent. The azimuth angle of the laser emitter 31 is obtained by obtaining the azimuth angle of the rotating block 25.

[0077] Specifically, a turntable 16 is fixedly connected to the end of the acceleration shaft 23, and the laser emitter 31 is fixed inside the turntable 16. A counterweight 30 is also fixedly connected inside the turntable 16 at a position symmetrical to the laser emitter 31 to reduce vibration during rotation.

[0078] Specifically, the photosensitive component 4 includes an optical fiber 33 at the front end and a photosensitive sensor 34 at the rear end. The photosensitive sensor 34 is a photoresistor, etc. The optical fiber 33 diverges horizontally forward and gradually converges at the end. The optical fiber 33 can realize non-linear propagation of light and concentrate the light at the tail. The sensing end of the photosensitive sensor 34 is located at the end of the optical fiber 33. The optical fiber emitted by the laser emitter 31 is conducted to the end of the optical fiber 33 and sensed by the photosensitive sensor 34.

[0079] Example 2 is a further improvement upon Example 1. Please refer to Example 1. Figure 1-13 A rotating ring 36 is rotatably connected to the outer side of the first bushing 9. A vertical rod 28 is fixedly connected to the bottom end of the rotating ring 36. A second laser rangefinder 29 is fixedly connected to the bottom end of the vertical rod 28. The second laser rangefinder 29 faces the lower side of the tire 8.

[0080] Specifically, the side of the tire 8 facing the second laser rangefinder 29 is coated with a reflective ring 20. After the second laser rangefinder 29 shines on the reflective ring 20, it can deduce the height change of the tire 8 axle caused by elastic deformation based on the width change at the bottom of the tire 8, thereby making compensation.

[0081] When the heavy-duty vehicle 6 accelerates or decelerates, the bottom of the tire 8 will experience height changes due to the increase and decrease of load, such as... Figure 13For example, when decelerating, the load on the front axle increases, and the axle center will lower;

[0082] The bottom width of tire 8 can reflect the height change of the tire 8 axle center at this time. The present invention uses a second laser rangefinder 29 with a fixed position to detect the width of the bottom position of tire 8, thereby obtaining the height change value of the bottom of tire 8, so as to achieve compensation when calculating the dynamic deflection of the bridge.

[0083] The mapping relationship between the bottom width of tire 8 and the axle height of tire 8 needs to be established through experiments in advance.

[0084] Specifically, a motor 35 is fixedly connected to the outer side of the first bushing 9, and a drive gear 37 is fixedly connected to the end of the main shaft of the motor 35. A half-tooth ring 38 is fixedly connected to the rotating ring 36 on one side of the motor 35. The drive gear 37 meshes with the half-tooth ring 38. Referring to the single-axis dynamic tilt sensor 24, it is used to compensate for the change in the angle of the vertical rod 28 caused by the inconsistent height of the front and rear axles of the heavy-duty vehicle 6.

[0085] Motor 35 is a self-locking motor. When the motor is not working, the rotating ring 36 rotates synchronously with the first bushing 9. When the telescopic rod 11 is tilted, the motor 35 drives the vertical rod 28 to rotate by driving the gear 37 and the half-tooth ring 38 to achieve angle compensation, ensuring that the position of the second laser rangefinder 29 is fixed relative to the bottom of the tire 8.

[0086] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dynamic load testing device for bridge bearing capacity, comprising a heavy-duty vehicle (6) and a support frame (3), characterized in that: The top of the support frame (3) is fixedly connected to a photosensitive component (4) and a first laser rangefinder (5). A reflector (7) is installed on the heavy-duty vehicle (6). The first laser rangefinder (5) can measure the horizontal distance a between itself and the center of the inner wheel hub of the tire (8) through the reflector (7). The front and rear wheel hubs of the heavy-duty vehicle (6) are bolted with positioning plates (18). The positioning plates (18) are concentric with the wheel hubs. One end of the positioning plate (18) is fixedly connected to a connecting shaft (39). The outer side of the connecting shaft (39) is rotatably connected to a first bushing (9). A telescopic rod (11) is connected between the two first bushings (9). The bottom end of the first bushing (9) is fixedly connected to a connecting rod (17), and the other end of the connecting rod (17) is fixedly connected to a fourth bushing (21). The inner side of the fourth bushing (21) is rotatably connected to an acceleration shaft (23). The acceleration shaft (23) is concentric with the hub. The acceleration shaft (23) and the connecting shaft (39) are connected through an acceleration assembly. The end of the acceleration shaft (23) is fixedly connected to a laser emitter (31). The laser emitter (31) accelerates as the hub rotates. The inner side of the fourth bushing (21) is fixedly connected to an angle sensor (22) to obtain the angle of the laser emitter (31). Every time the laser emitter (31) rotates, a beam of light is captured by the photosensitive assembly (4). The angle d of the laser emitter (31) relative to the ground at the time of capture is obtained, and the real-time height b of the connecting shaft (39) is calculated by trigonometric functions.

2. The dynamic load testing device for bridge bearing capacity according to claim 1, characterized in that: Two first bushings (9) are fixedly connected to a connecting pipe (10) on one side. The two connecting pipes (10) are detachably connected to a telescopic rod (11) by means of a threaded connection. A single-axis dynamic tilt sensor (24) is fixedly connected to one side of the telescopic rod (11).

3. The dynamic load testing device for bridge bearing capacity according to claim 1, characterized in that: The first gear (13) is fixedly connected to the end of the connecting shaft (39), the fourth gear (32) is fixedly connected to the outer side of the acceleration shaft (23), the third shaft sleeve (19) is fixedly connected to the top of the first shaft sleeve (9), the second shaft sleeve (12) is fixedly connected to the top of the fourth shaft sleeve (21), the second gear (14) and the third gear (15) are coaxially rotatably connected to the inner side of the third shaft sleeve (19) and the second shaft sleeve (12), the diameter of the third gear (15) is larger than that of the second gear (14), the second gear (14) meshes with the first gear (13), the diameter of the second gear (14) is smaller than that of the first gear (13), the third gear (15) meshes with the fourth gear (32), the diameter of the fourth gear (32) is smaller than that of the third gear (15), by utilizing the self-rotation of the hub when it moves forward, and by the speed-increasing effect between the gears, the high-speed rotation of the laser emitter (31) is achieved, thereby increasing the sampling frequency.

4. A dynamic load testing device for bridge bearing capacity according to any one of claims 1-3, characterized in that: The reflector (7) is fixedly installed on the side of the first bushing (9) facing the first laser rangefinder (5) or directly above the heavy-duty vehicle (6).

5. A dynamic load testing device for bridge bearing capacity according to any one of claims 1-3, characterized in that: A rotating block (25) is embedded in the inner side of the acceleration shaft (23). The rotating block (25) is slidably connected to the inner side of the angle sensor (22). The azimuth angle of the rotating block (25) and the laser emitter (31) on the acceleration shaft (23) is consistent. The azimuth angle of the laser emitter (31) is obtained by obtaining the azimuth angle of the rotating block (25).

6. A dynamic load testing device for bridge bearing capacity according to any one of claims 1-3, characterized in that: A turntable (16) is fixedly connected to the end of the acceleration shaft (23). The laser emitter (31) is fixed inside the turntable (16). A counterweight (30) is also fixedly connected to the turntable (16) at a position symmetrical to the laser emitter (31) to reduce vibration during rotation.

7. A dynamic load testing device for bridge bearing capacity according to any one of claims 1-3, characterized in that: The photosensitive component (4) includes an optical fiber (33) at the front end and a photosensitive sensor (34) at the rear end. The optical fiber (33) spreads horizontally forward and gradually converges at the end. The sensing end of the photosensitive sensor (34) is located at the end of the optical fiber (33). The optical fiber emitted by the laser emitter (31) passes through the optical fiber (33) and is conducted to the end and sensed by the photosensitive sensor (34).

8. A dynamic load testing device for bridge bearing capacity according to any one of claims 1-3, characterized in that: A rotating ring (36) is rotatably connected to the outer side of the first bushing (9). A vertical rod (28) is fixedly connected to the bottom end of the rotating ring (36). A second laser rangefinder (29) is fixedly connected to the bottom end of the vertical rod (28). The second laser rangefinder (29) faces the bottom of the tire (8).

9. The dynamic load testing device for bridge bearing capacity according to claim 8, characterized in that: The tire (8) is coated with a reflective ring (20) on the side facing the second laser rangefinder (29). After the second laser rangefinder (29) shines on the reflective ring (20), it can deduce the height change of the tire (8) axle caused by elastic deformation based on the width change of the bottom end of the tire (8), thereby compensating for the change.

10. The dynamic load testing device for bridge bearing capacity according to claim 9, characterized in that: A motor (35) is fixedly connected to the outside of the first bushing (9). A drive gear (37) is fixedly connected to the end of the main shaft of the motor (35). A half-tooth ring (38) is fixedly connected to the side of the rotating ring (36) on the motor (35). The drive gear (37) meshes with the half-tooth ring (38). Referring to the single-axis dynamic tilt sensor (24), it is used to compensate for the change in the angle of the vertical rod (28) caused by the inconsistent height of the front and rear axles of the heavy-duty vehicle (6).

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