A road crack detection device and a municipal road crack length detection method

Abstract

The present application relates to the technical field of road engineering detection, and specifically relates to a road crack detection device and a municipal road crack length detection method, which comprises a cart, an air head and a distance sensor. A blowing assembly is arranged on the cart and connected with the air head. A brush is arranged on the cart through a reciprocating assembly. The reciprocating assembly is connected with the blowing assembly through a transmission assembly. A water tank is fixed on the cart. A spray head is connected with the water tank through a negative pressure extraction assembly. The negative pressure extraction assembly is linked with the transmission assembly. Through the cooperation of the blowing assembly and the air head, loose sundries in the crack can be blown away, so that the crack profile is fully exposed. Meanwhile, the reciprocating cleaning action of the brush can further remove stubborn dust attached to the edge of the crack. The intermittent watering of the spray head can effectively inhibit dust raising and wet the road surface, so as to avoid dry dust from blocking the crack details, thus creating a clean and clear detection environment for the distance sensor, thereby ensuring the accuracy of the crack length measurement.

Description

Technical Field

[0001] This invention relates to the field of road engineering testing technology, specifically a road crack detection device and a method for detecting the length of cracks in municipal roads. Background Technology

[0002] In the road maintenance and management of municipal engineering projects, cracks are one of the most common types of defects in asphalt and cement concrete pavements. Accurately obtaining their length parameters is crucial for assessing the extent of pavement damage, developing repair plans, and predicting the remaining service life of the road. However, due to the long-term exposure of roads to the natural environment, dust, gravel, fallen leaves, and other debris often accumulate inside cracks. Simultaneously, stubborn contaminants such as oil and mud often adhere to the crack edges. These interfering factors severely obscure the true outline of the cracks, making length measurement significantly difficult.

[0003] Currently, the detection of road crack length mainly relies on manual measurement or image recognition equipment. Manual measurement requires inspectors to use rulers or measuring tapes to measure segment by segment along the crack's direction. This is not only labor-intensive and inefficient, but the results are also easily affected by human factors, making it difficult to guarantee data consistency and objectivity. While image recognition technology can achieve non-contact and rapid measurement, practical applications have shown that when debris accumulates within the crack or there is significant road dust, the image acquisition quality deteriorates significantly, causing the recognition algorithm to fail to accurately extract the crack boundaries, resulting in measurement errors or even missed detections.

[0004] To address these issues, some testing equipment is equipped with simple cleaning devices or water spray dust suppression systems. However, these devices typically require independent power sources and control systems, resulting in complex equipment structures, high energy consumption, and a lack of effective coordination between cleaning and testing actions. This often leads to incomplete cleaning or asynchronous cleaning and testing, making it difficult to meet the demand for efficient and accurate road crack detection. Summary of the Invention

[0005] The purpose of this invention is to provide a road crack detection device and a method for detecting the length of cracks in municipal roads, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A road crack detection device includes a trolley, a blower, and a distance sensor. The blower and the distance sensor are respectively fixedly installed at both ends of the trolley. The trolley is equipped with a blowing assembly connected to the blower. When the blowing assembly is running, the blower blows a high-pressure airflow onto the road surface. It also includes a brush, a nozzle, and a water tank. The brush is mounted on the trolley via a reciprocating assembly. The reciprocating assembly is connected to the blower assembly via a transmission assembly. During the operation of the blower assembly, the transmission assembly drives the reciprocating assembly to move, thereby causing the brush to move horizontally back and forth along a direction perpendicular to the forward direction of the trolley. The water tank is fixed on the trolley, and the nozzle is connected to the water tank through a negative pressure extraction component. The negative pressure extraction component is linked to the transmission component. Driven by the transmission component, the negative pressure extraction component intermittently sprays the water in the water tank onto the road surface through the nozzle. The distance sensor is used to detect the length of road cracks after treatment by the wind turbine, brush, and nozzle.

[0007] The road crack detection equipment described above: The blower assembly includes a fan and a motor, both of which are fixedly mounted on the trolley. The output end of the motor is fixedly connected to the impeller of the fan on the same axis, and the air outlet of the fan and the fan head are connected by a duct.

[0008] The road crack detection equipment described above: The reciprocating assembly includes a movable frame, a driving sprocket, and a driven sprocket. The movable frame is horizontally slidably mounted on the trolley along a direction perpendicular to the forward movement of the trolley, and the brush is fixed to the bottom of the movable frame. The driving sprocket and the driven sprocket are symmetrically mounted on the trolley with the moving frame as the axis of rotation, and the driving sprocket and the driven sprocket are connected by a chain.

[0009] The road crack detection equipment described above: A slider is rotatably mounted on one of the links of the chain, and a groove is provided on the top of the movable frame; The slider is slidably fitted into the groove, and the length of the groove is greater than the diameter of the driving sprocket and the driven sprocket.

[0010] The road crack detection equipment described above: The transmission assembly includes a transmission rod and a reversing rod, both of which are rotatably mounted on the trolley. One end of the transmission rod is coaxially fixed with a drive bevel gear. One end of the reversing rod is coaxially fixedly provided with a driven bevel gear that meshes with the driving bevel gear, and the other end of the reversing rod is coaxially fixedly connected to the driving sprocket.

[0011] The road crack detection equipment described above: A main pulley is coaxially fixed on the output end of the motor, and a secondary pulley is coaxially fixed on the transmission rod. The main pulley and the secondary pulley are connected by a toothed belt.

[0012] The road crack detection equipment described above: The negative pressure extraction assembly includes a cylindrical shell, a piston rod, and a connecting rod, with the cylindrical shell fixed to the trolley; One end of the piston rod is inserted into the cylindrical shell and slides in contact with it, and the diameter of one end of the piston rod is the same as that of the inner wall of the cylindrical shell.

[0013] The road crack detection equipment described above: A disc is coaxially fixed at the other end of the transmission rod, and an eccentric column is fixedly mounted on the disc. The two ends of the connecting rod are rotatably connected to the eccentric column and the other end of the piston rod, respectively.

[0014] The road crack detection equipment described above: A main pipe is horizontally fixed on the trolley, and multiple nozzles are evenly arranged along a straight line at the bottom of the main pipe. The bottom of the water tank and the other end of the cylinder shell are connected by a conduit, and a one-way valve is provided on the conduit. The bottom of the other end of the cylindrical shell and the top of the main pipe are connected by a connecting pipe, and a second one-way valve is installed on the connecting pipe.

[0015] A method for detecting cracks in municipal roads using the aforementioned road crack detection equipment, characterized by comprising the following steps: Step 1: Start the motor to run the fan. The high-pressure airflow is blown from the fan head to the road surface through the air duct to remove loose debris from the cracks. Step 2: While the motor is running, the main pulley drives the auxiliary pulley to rotate through the toothed belt. The transmission rod rotates accordingly and drives the reversing rod to rotate through the meshing of the active bevel gear and the driven bevel gear. The reversing rod drives the active sprocket to rotate, and drives the driven sprocket to rotate synchronously through the chain. The slider on the chain slides in the groove and pushes the moving frame to move horizontally back and forth along the direction perpendicular to the forward direction of the trolley. The brush moves back and forth synchronously with the moving frame to clean the edges of the cracks. Step 3: As the transmission rod rotates, the disc at the other end rotates synchronously. The eccentric column drives the piston rod to reciprocate linearly inside the cylinder through the connecting rod. When the piston rod is pulled out, the first one-way valve opens, and the water in the water tank is drawn into the cylinder. When the piston rod is pushed in, the second one-way valve opens, and the water in the cylinder is pushed to the main pipe and intermittently sprayed onto the road surface by each nozzle. Step 4: After the road surface area has been treated by wind sweeping, brush reciprocating sweeping, and intermittent spraying, the length of the road cracks is detected by a distance sensor.

[0016] Compared with the prior art, the beneficial effects of the present invention are: By combining the blower assembly and the blower head, loose debris inside the crack can be blown away, fully exposing the crack outline. At the same time, the reciprocating sweeping motion of the brush can further remove stubborn dust attached to the crack edge, while the intermittent water spraying of the nozzle can effectively suppress dust and wet the road surface, preventing dry dust from obscuring the crack details. The three work together to create a clean and clear detection environment for the distance sensor, thereby ensuring the accuracy of crack length measurement. The blower assembly serves as the power source, driving the reciprocating assembly and the negative pressure extraction assembly simultaneously through the transmission assembly. This allows the three cleaning actions—blowing, brush reciprocating cleaning, and intermittent spraying—to be performed synchronously with the trolley's movement. The multi-path transmission design of a single power source avoids the need to configure separate drive devices for each cleaning stage, realizing an integrated process of cleaning and inspection operations and improving the overall efficiency of road crack detection. Because the blowing assembly, reciprocating assembly, and negative pressure extraction assembly are linked by mechanical transmission, there is no need to set up an additional independent motor or control system for brush movement and water spray control, which reduces the number of power units and the configuration of electrical control components. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a road crack detection device.

[0018] Figure 2 This is a schematic diagram of the overall structure of a road crack detection device from another perspective.

[0019] Figure 3 This is a cross-sectional view of the trolley used in a road crack detection device.

[0020] Figure 4 for Figure 3 Enlarged view of point A in the middle.

[0021] Figure 5 This is another schematic diagram of the overall structure of the road crack detection equipment.

[0022] Figure 6 This is a schematic diagram showing the disassembly of the slider and groove in a road crack detection device.

[0023] Figure 7 This is a cross-sectional view of the trolley, water tank, and shell of a road crack detection device.

[0024] Figure 8 for Figure 7 Enlarged view of section B in the middle.

[0025] Figure 9 In order to be in Figure 7 A schematic diagram from another perspective based on the above.

[0026] Figure 10 for Figure 9 Enlarged view of point C in the middle.

[0027] In the diagram: 1. Cart; 2. Fan head; 3. Distance sensor; 4. Brush; 5. Nozzle; 6. Water tank; 7. Fan; 8. Motor; 9. Air duct; 10. Moving frame; 1001. Slide rail; 11. Drive sprocket; 12. Driven sprocket; 13. Chain; 14. Slider; 15. Transmission rod; 16. Reversing rod; 17. Driven bevel gear; 18. Driven bevel gear; 19. Main pulley; 20. Secondary pulley; 21. Toothed belt; 22. Cylinder shell; 23. Piston rod; 24. Disc; 25. Eccentric column; 26. Connecting rod; 27. Main pipe; 28. Guide pipe; 29. ​​Through pipe; 30. Check valve No. 1; 31. Check valve No. 2. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] Please see Figure 1-10 As an embodiment of the present invention, a road crack detection device includes a trolley 1, a blower 2, and a distance sensor 3. The blower 2 and the distance sensor 3 are respectively fixedly installed at both ends of the trolley 1. The trolley 1 is provided with a blowing assembly connected to the blower 2. When the blowing assembly is running, the blower 2 will blow high-pressure airflow onto the road surface. It also includes a brush 4, a nozzle 5, and a water tank 6. The brush 4 is mounted on the trolley 1 via a reciprocating assembly. The reciprocating assembly is connected to the blower assembly via a transmission assembly. During the operation of the blower assembly, the transmission assembly drives the reciprocating assembly to move, thereby causing the brush 4 to move horizontally back and forth along a direction perpendicular to the forward direction of the trolley 1. The water tank 6 is fixed on the trolley 1. The nozzle 5 is connected to the water tank 6 through a negative pressure extraction component. The negative pressure extraction component is linked with the transmission component. Driven by the transmission component, the negative pressure extraction component intermittently sprays the water in the water tank 6 onto the road surface through the nozzle 5. The distance sensor 3 is used to detect the length of road cracks after they have been treated by the wind turbine 2, brush 4 and nozzle 5.

[0030] In this embodiment, the blowing assembly serves as the core power source of the entire machine. After startup, it generates a high-pressure airflow and blows it onto the road surface through the blower head 2 to remove loose debris from the cracks. At the same time, the mechanical power generated by the blowing assembly is split and transmitted through the transmission assembly: one path is transmitted to the reciprocating assembly, which drives the brush 4 to move horizontally back and forth in a direction perpendicular to the forward movement of the trolley 1, mechanically cleaning the stubborn dust attached to the edge of the crack; the other path is transmitted to the negative pressure extraction assembly, which creates an intermittent negative pressure between the water tank 6 and the nozzle 5, intermittently spraying the water in the water tank 6 onto the road surface through the nozzle 5, thereby reducing dust and wetting the surface. The three cleaning actions—blowing by the blower 2, reciprocating sweeping by the brush 4, and intermittent spraying by the nozzle 5—are all mechanically linked by a single power source, the blower assembly, and are synchronized with the movement of the trolley 1. After the road surface area is cleaned, the distance sensor 3, which is fixed to the other end of the trolley 1, detects the length of the cracks, thus forming a continuous operation process of "blowing-sweeping-spraying-detection".

[0031] As a further embodiment of the present invention, the blower assembly includes a fan 7 and a motor 8, both of which are fixedly mounted on the trolley 1. The output end of the motor 8 is coaxially and fixedly connected to the impeller of the fan 7, and the air outlet of the fan 7 and the fan head 2 are connected by the air duct 9.

[0032] In this embodiment, please refer to Figure 1 and Figure 2 The motor 8 is fixedly installed on the trolley 1 as a power source. Its output end is fixedly connected to the impeller of the fan 7 on the same axis. When the motor 8 runs, it directly drives the impeller of the fan 7 to rotate and generate high-pressure airflow. The air force generated by the fan 7 is guided through the air outlet and the air duct 9 and delivered to the fan head 2. Finally, the fan head 2 blows high-pressure airflow onto the road surface to sweep away and remove debris from the cracks.

[0033] As a further embodiment of the present invention, the reciprocating assembly includes a movable frame 10, a driving sprocket 11 and a driven sprocket 12. The movable frame 10 is horizontally slidably mounted on the trolley 1 along a direction perpendicular to the forward direction of the trolley 1, and the brush 4 is fixed to the bottom of the movable frame 10. The driving sprocket 11 and the driven sprocket 12 are symmetrically rotated on the trolley 1 about the moving frame 10 as an axis, and the driving sprocket 11 and the driven sprocket 12 are connected by a chain 13; A slider 14 is rotatably mounted on one of the links of the chain 13, and a groove 1001 is provided on the top of the movable frame 10; The slider 14 is slidably fitted into the groove 1001, and the length of the groove 1001 is greater than the diameter of the driving sprocket 11 and the driven sprocket 12.

[0034] In this embodiment, please refer to Figure 4 , Figure 5 and Figure 6 When the drive sprocket 11 rotates, it drives the driven sprocket 12 to rotate synchronously through the chain 13, and the chain 13 rotates in a cycle. The slider 14, which is rotatably mounted on the chain 13, moves with the chain links. At the same time, the slider 14 is slidably fitted into the groove 1001 on the top of the moving frame 10. The length of the groove 1001 is greater than the diameter of the driving sprocket 11 and the driven sprocket 12, providing sufficient space for the slider 14 to move. As the chain 13 rotates in a cycle, the slider 14 slides relative to the slide groove 1001 and pushes the moving frame 10, causing the moving frame 10 to slide horizontally back and forth on the trolley 1 in a direction perpendicular to the forward movement of the trolley 1. Since the brush 4 is fixed to the bottom of the moving frame 10, the reciprocating motion of the moving frame 10 drives the brush 4 to move horizontally back and forth synchronously, thereby achieving mechanical cleaning of the edges of road cracks.

[0035] As a further embodiment of the present invention, the transmission assembly includes a transmission rod 15 and a reversing rod 16, both of which are rotatably mounted on the trolley 1. One end of the transmission rod 15 is coaxially fixedly provided with a drive bevel gear 17. One end of the reversing rod 16 is coaxially fixedly provided with a driven bevel gear 18 that meshes with the driving bevel gear 17, and the other end of the reversing rod 16 is coaxially fixedly connected to the driving sprocket 11. A main pulley 19 is coaxially fixed on the output end of the motor 8, and a secondary pulley 20 is coaxially fixed on the transmission rod 15. The main pulley 19 and the secondary pulley 20 are connected by a toothed belt 21.

[0036] In this embodiment, please refer to Figure 3 and Figure 4 The main pulley 19, which is coaxially fixed on the output end of the motor 8, is connected to the auxiliary pulley 20, which is coaxially fixed on the transmission rod 15, through the toothed belt 21. When the motor 8 is running, the main pulley 19 drives the auxiliary pulley 20 to rotate through the toothed belt 21, thereby driving the transmission rod 15 to rotate. The driving bevel gear 17, which is coaxially fixed at one end of the transmission rod 15, rotates accordingly and meshes with the driven bevel gear 18, which is coaxially fixed at one end of the reversing rod 16, so as to transmit the rotational motion of the transmission rod 15 to the reversing rod 16 and realize the conversion of the transmission direction. The other end of the reversing rod 16 is coaxially and fixedly connected to the drive sprocket 11. The rotation of the reversing rod 16 directly drives the drive sprocket 11 to rotate, thereby driving the reciprocating assembly to run and realize the horizontal reciprocating movement of the brush 4.

[0037] As a further embodiment of the present invention, the negative pressure extraction assembly includes a cylindrical shell 22, a piston rod 23 and a connecting rod 26, wherein the cylindrical shell 22 is fixed to the trolley 1; One end of the piston rod 23 is inserted into the cylindrical shell 22 and slides in cooperation with it. The diameter of one end of the piston rod 23 is the same as that of the inner wall of the cylindrical shell 22. The other end of the transmission rod 15 is coaxially fixed with a disk 24, and an eccentric column 25 is fixedly mounted on the disk 24. The two ends of the connecting rod 26 are respectively rotatably connected to the eccentric column 25 and the other end of the piston rod 23. The trolley 1 is horizontally fixed with a main pipe 27. The number of nozzles 5 is multiple and evenly arranged in a straight line at the bottom of the main pipe 27. The bottom of the water tank 6 and the other end of the cylinder shell 22 are connected by a conduit 28. A first-way valve 30 is provided on the conduit 28. The bottom of the other end of the cylindrical shell 22 and the top of the main pipe 27 are connected by a through pipe 29, and a second one-way valve 31 is provided on the through pipe 29.

[0038] In this embodiment, please refer to Figure 8 and Figure 10 The disk 24, which is coaxially fixed at the other end of the transmission rod 15, rotates synchronously with the transmission rod 15, and the eccentric column 25 fixed on the disk 24 moves in a circular motion around the center of the disk 24. The eccentric column 25 is rotatably connected to one end of the connecting rod 26, and the other end of the connecting rod 26 is rotatably connected to the other end of the piston rod 23. The circular motion of the eccentric column 25 is converted into the linear reciprocating motion of the piston rod 23 through the connecting rod 26. One end of the piston rod 23 is inserted into the cylinder shell 22 and slides against the inner wall of the cylinder shell 22. The reciprocating motion of the piston rod 23 causes periodic volume changes inside the cylinder shell 22, thereby generating suction and pushing effects. The bottom of the water tank 6 is connected to the other end of the shell 22 through a conduit 28. A first check valve 30 is installed on the conduit 28. The bottom of the other end of the shell 22 is connected to the top of the main pipe 27 through a connecting pipe 29. A second check valve 31 is installed on the connecting pipe 29. When the piston rod 23 is pulled out of the cylinder shell 22, a negative pressure is formed inside the cylinder shell 22. The first one-way valve 30 opens and the second one-way valve 31 closes. Water in the water tank 6 is drawn into the cylinder shell 22 through the conduit 28. When the piston rod 23 is pushed into the cylinder shell 22, a positive pressure is formed inside the cylinder shell 22. The first one-way valve 30 closes and the second one-way valve 31 opens. Water in the cylinder shell 22 is pushed to the main pipe 27 through the connecting pipe 29. The main pipe 27 is horizontally fixed on the trolley 1. Multiple nozzles 5 are evenly arranged along a straight line at its bottom. After the water enters the main pipe 27, it is intermittently sprayed onto the road surface by each nozzle 5 to achieve the function of dust suppression and wetting.

[0039] A method for detecting cracks in municipal roads using the aforementioned road crack detection equipment, characterized by comprising the following steps: Step 1: Start the motor to run the fan. The high-pressure airflow is blown from the fan head to the road surface through the air duct to remove loose debris from the cracks. Step 2: While the motor is running, the main pulley drives the auxiliary pulley to rotate through the toothed belt. The transmission rod rotates accordingly and drives the reversing rod to rotate through the meshing of the active bevel gear and the driven bevel gear. The reversing rod drives the active sprocket to rotate, and drives the driven sprocket to rotate synchronously through the chain. The slider on the chain slides in the groove and pushes the moving frame to move horizontally back and forth along the direction perpendicular to the forward direction of the trolley. The brush moves back and forth synchronously with the moving frame to clean the edges of the cracks. Step 3: As the transmission rod rotates, the disc at the other end rotates synchronously. The eccentric column drives the piston rod to reciprocate linearly inside the cylinder through the connecting rod. When the piston rod is pulled out, the first one-way valve opens, and the water in the water tank is drawn into the cylinder. When the piston rod is pushed in, the second one-way valve opens, and the water in the cylinder is pushed to the main pipe and intermittently sprayed onto the road surface by each nozzle. Step 4: After the road surface area has been treated by wind sweeping, brush reciprocating sweeping, and intermittent spraying, the length of the road cracks is detected by a distance sensor.

[0040] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0041] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A road crack detection device, comprising a trolley (1), a wind turbine (2), and a distance sensor (3), wherein the wind turbine (2) and the distance sensor (3) are respectively fixedly disposed at both ends of the trolley (1), characterized in that, The trolley (1) is equipped with a blower assembly connected to the blower head (2). When the blower assembly is running, the blower head (2) will blow high-pressure airflow onto the road surface. It also includes a brush (4), a nozzle (5) and a water tank (6). The brush (4) is mounted on the trolley (1) via a reciprocating assembly. The reciprocating assembly is connected to the blower assembly via a transmission assembly. During the operation of the blower assembly, the transmission assembly drives the reciprocating assembly to run, thereby causing the brush (4) to move horizontally back and forth in a direction perpendicular to the forward direction of the trolley (1). The water tank (6) is fixed on the trolley (1). The nozzle (5) is connected to the water tank (6) through the negative pressure extraction component. The negative pressure extraction component is linked with the transmission component. Under the drive of the transmission component, the negative pressure extraction component sprays the water in the water tank (6) intermittently onto the road surface through the nozzle (5). The distance sensor (3) is used to detect the length of road cracks after they have been treated by the wind head (2), brush (4) and nozzle (5).

2. The road crack detection device according to claim 1, characterized in that, The blower assembly includes a fan (7) and a motor (8), both of which are fixedly mounted on the trolley (1); The output end of the motor (8) is coaxially and fixedly connected to the impeller of the fan (7), and the air outlet of the fan (7) and the air head (2) are connected by the air duct (9).

3. The road crack detection device according to claim 2, characterized in that, The reciprocating assembly includes a moving frame (10), a driving sprocket (11), and a driven sprocket (12). The moving frame (10) is horizontally slidably mounted on the trolley (1) along the forward direction perpendicular to the trolley (1). The brush (4) is fixed to the bottom of the moving frame (10). The driving sprocket (11) and the driven sprocket (12) are symmetrically rotated on the trolley (1) with the moving frame (10) as the axis, and the driving sprocket (11) and the driven sprocket (12) are connected by a chain (13).

4. The road crack detection device according to claim 3, characterized in that, A slider (14) is rotatably mounted on one of the links of the chain (13), and a groove (1001) is provided on the top of the movable frame (10). The slider (14) is slidably fitted into the groove (1001), the length of which is greater than the diameter of the driving sprocket (11) and the driven sprocket (12).

5. A road crack detection device according to claim 3, characterized in that, The transmission assembly includes a transmission rod (15) and a reversing rod (16). Both the transmission rod (15) and the reversing rod (16) are rotatably mounted on the trolley (1). One end of the transmission rod (15) is coaxially fixed with a drive bevel gear (17). One end of the reversing rod (16) is coaxially fixedly provided with a driven bevel gear (18) that meshes with the driving bevel gear (17), and the other end of the reversing rod (16) is coaxially fixedly connected to the driving sprocket (11).

6. A road crack detection device according to claim 5, characterized in that, A main pulley (19) is coaxially fixed on the output end of the motor (8), and a secondary pulley (20) is coaxially fixed on the transmission rod (15). The main pulley (19) and the secondary pulley (20) are connected by a toothed belt (21).

7. A road crack detection device according to claim 5, characterized in that, The negative pressure extraction assembly includes a cylindrical shell (22), a piston rod (23) and a connecting rod (26), wherein the cylindrical shell (22) is fixed on the trolley (1); One end of the piston rod (23) is inserted into the cylindrical shell (22) and slides in cooperation with it. The diameter of one end of the piston rod (23) is the same as that of the inner wall of the cylindrical shell (22).

8. A road crack detection device according to claim 7, characterized in that, A disc (24) is coaxially fixed at the other end of the transmission rod (15), and an eccentric column (25) is fixedly mounted on the disc (24). The two ends of the connecting rod (26) are rotatably connected to the other end of the eccentric column (25) and the piston rod (23), respectively.

9. A road crack detection device according to claim 7, characterized in that, The trolley (1) is horizontally fixed with a main pipe (27), and the number of nozzles (5) is multiple and evenly arranged along a straight line at the bottom of the main pipe (27). The bottom of the water tank (6) and the other end of the cylinder shell (22) are connected by a conduit (28), and a first-way valve (30) is provided on the conduit (28). The bottom of the other end of the cylindrical shell (22) and the top of the main pipe (27) are connected by a connecting pipe (29), and a second one-way valve (31) is provided on the connecting pipe (29).

10. A method for detecting the length of cracks in municipal roads using the road crack detection equipment according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Start the motor to run the fan. The high-pressure airflow is blown from the fan head to the road surface through the air duct to remove loose debris from the cracks. Step 2: While the motor is running, the main pulley drives the auxiliary pulley to rotate through the toothed belt. The transmission rod rotates accordingly and drives the reversing rod to rotate through the meshing of the active bevel gear and the driven bevel gear. The reversing rod drives the active sprocket to rotate, and drives the driven sprocket to rotate synchronously through the chain. The slider on the chain slides in the groove and pushes the moving frame to move horizontally back and forth along the direction perpendicular to the forward direction of the trolley. The brush moves back and forth synchronously with the moving frame to clean the edges of the cracks. Step 3: As the transmission rod rotates, the disc at the other end rotates synchronously. The eccentric column drives the piston rod to reciprocate linearly inside the cylinder through the connecting rod. When the piston rod is pulled out, the first one-way valve opens, and the water in the water tank is drawn into the cylinder. When the piston rod is pushed in, the second one-way valve opens, and the water in the cylinder is pushed to the main pipe and intermittently sprayed onto the road surface by each nozzle. Step 4: After the road surface area has been treated by wind sweeping, brush reciprocating sweeping, and intermittent spraying, the length of the road cracks is detected by a distance sensor.

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