Crack acoustic emission monitoring device and method for a crane boom
By designing automated monitoring devices and methods, the safety and efficiency issues of monitoring cracks in crane booms have been solved, achieving automated monitoring without manual climbing and efficient micro-crack detection.
Patent Information
- Application Number
- CN202611145048.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-30
- Publication Date
- 2026-08-25
AI Technical Summary
Existing methods for monitoring cracks in crane booms are unsafe and inefficient, especially for multi-point monitoring of long-distance robotic arms. Climbing up to fix the monitoring probes poses safety hazards and is also inefficient.
Design a device that includes a displacement mechanism and a monitoring mechanism. The device enables automatic movement of the monitoring probe through a cable and a retraction assembly. The device uses a combination of magnetic blocks and baffles to ensure that the probe does not come into contact with the boom during movement. The device also uses a striking assembly to generate elastic stress waves, thereby activating acoustic emission signals from microcracks and closed cracks.
It enables monitoring without the need for manual climbing of the boom, ensuring high safety, simplifying operation, improving the detection rate of microcracks, and enhancing monitoring efficiency.
Smart Images
Figure CN122631773A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of crack monitoring technology, specifically relating to an acoustic emission monitoring device and method for cracks in crane booms. Background Technology
[0002] Lifting machinery is widely used in engineering construction, port loading and unloading, and other fields. As a core load-bearing component, the boom is subjected to complex alternating load conditions for a long time, making it highly susceptible to fatigue cracks that can continue to propagate and potentially lead to major safety accidents such as boom breakage and equipment overturning. Therefore, it is necessary to regularly monitor the boom for crack conditions.
[0003] Currently, the commonly used method for spot-checking boom cracks on-site is acoustic emission monitoring. This method involves applying a coupling agent to the probe end to transmit stress waves to the boom's base material. However, existing booms are telescopic structures. For these long-distance robotic arms, the act of climbing up to fix the monitoring probe has a low safety factor, and the operation is inefficient for multi-point monitoring of long-distance robotic arms. Summary of the Invention
[0004] The purpose of this invention is to provide a simple and reasonably designed acoustic emission monitoring device and method for cracks in crane booms in order to solve the above-mentioned problems.
[0005] The present invention achieves the above objectives through the following technical solutions: In a first aspect, the present invention provides an acoustic emission monitoring device for cracks in a crane boom, comprising: A shifting mechanism is mounted on the boom body. The shifting mechanism includes a cable and a retraction assembly. The output end of the retraction assembly is connected to the cable, which is in a taut state. The extension direction of the cable is parallel to the extension direction of the boom body. A monitoring mechanism is installed on the cable. The monitoring mechanism includes a monitoring probe, which is positioned facing the structural surface of the boom body. Driven by the retraction and extension assembly, the monitoring mechanism moves with the retracted cable to adjust the monitoring position of the monitoring probe on the boom body.
[0006] Preferably, the take-up and extend assembly includes a take-up and extend drive, a winding roller, and a steering roller. Two winding rollers are rotatably mounted on a support, which is fixedly mounted on the fixed end of the boom body. The input end of the winding roller is connected to the take-up and extend drive. Both ends of the cable are wound around the winding roller. The steering roller is rotatably mounted on the extended end of the boom body. The cable between the two winding rollers passes around the steering roller for steering.
[0007] Preferably, a tension sensor is installed on the support, and a guide wheel is fixedly provided at the tension end of the tension sensor. The guide wheel is correspondingly provided with the roller, and the end of the cable near the roller passes around the corresponding guide wheel.
[0008] Preferably, the monitoring mechanism further includes a first spring, a housing, magnetic blocks, a barrier plate, and a contact plate. An end cap is fixedly installed at the upper end of the housing, and a sleeve is fixedly installed at the upper end of the end cap. The sleeve is slidably installed on a guide post, and the outer end of the guide post is fixedly installed on a cable by a clamp. The portion of the guide post located inside the sleeve is fitted with the first spring. The monitoring probe is installed inside the housing. Multiple magnetic blocks are distributed around the monitoring probe and fixedly installed inside the housing. A contact plate is fixedly installed at the end of the housing away from the end cap. The barrier plate is rotatably installed inside the contact plate. A through hole is opened on the barrier plate, and the through hole is corresponding to the magnetic block. A toothed ring is fixedly installed around the periphery of the barrier plate. The toothed ring meshes with a gear, and the input end of the gear is connected to a barrier drive component. Before the monitoring probe performs detection, the barrier plate rotates under the drive of the barrier drive component until the exposed window hole and the through hole of the magnetic block are not connected; when the monitoring probe moves to the monitoring position, the barrier plate rotates under the drive of the barrier drive component until the exposed window hole and the through hole of the magnetic block are connected, and the abutment plate abuts against the surface of the boom body.
[0009] Preferably, the monitoring end of the monitoring probe is located outside the housing, and an upper retaining ring is provided on the inner edge of the monitoring probe. A lower retaining ring is also provided on the housing, and the lower retaining ring is located below the upper retaining ring. The monitoring probe slides with the housing through the upper and lower retaining rings. A second spring is fixedly installed at the upper end of the upper retaining ring. Before the monitoring probe performs detection, the lower end face of the monitoring probe in the initial position is lower than the lower end face of the abutment plate.
[0010] Preferably, multiple support frames are also installed on the cable between the clamp and the fixed end of the boom body. Limiting rollers are rotatably installed on the support frames. The cable passes through the pair of limiting rollers and rubs against the limiting rollers. Supporting rollers are also rotatably installed on the support frames. The data line of the monitoring probe is connected to the supporting roller.
[0011] Preferably, the device further includes a striking assembly, which includes a striking hammer, a hammer rod, and a striking drive assembly. A guide seat is fixedly installed on the outside of the housing. The hammer rod is vertically slidably installed in the guide seat. A striking hammer is fixedly installed at one end of the hammer rod that extends to the guide seat. The output end of the striking drive assembly is connected to the hammer rod for driving the hammer rod to slide vertically back and forth.
[0012] Preferably, the striking drive assembly includes a striking drive component, a cam, a lifting rod, and a third spring. The upper end of the hammer rod is fixedly connected to the third spring, the side of the hammer rod is fixedly connected to the lifting rod, and the output end of the striking drive component is drivenly connected to the cam, which frictionally abuts against the lifting rod.
[0013] Preferably, the side of the housing and the side of the abutment plate are respectively fixedly provided with ear plates, the ear plates are arranged in pairs, and the paired ear plates are fixedly connected by locking pins.
[0014] Secondly, the present invention also provides a method for applying the above-mentioned acoustic emission monitoring device for cracks in the boom of lifting machinery, the method comprising the following steps: The monitoring equipment was installed on a taut cable; The cable is unwound using the take-up and unwind assembly. The taut cable is unwound along the extension direction of the boom body, and the cable drives the monitoring mechanism to move in the same direction until the monitoring probe is in the monitoring position to monitor cracks in the boom body.
[0015] The present invention has at least the following beneficial effects: The present invention provides a crane boom crack acoustic emission monitoring device and method, which moves and adjusts the position of the monitoring probe in the monitoring mechanism on the boom body by winding and unwinding the cable, without the need for a person to climb up the boom body to move the monitoring mechanism, making the operation simple and the safety factor high. Furthermore, multiple magnetic blocks are arranged around the periphery of the monitoring probe inside the housing. Before the monitoring mechanism moves to the monitoring position, the exposure window of the monitoring probe is blocked by a barrier plate to block the magnetic attraction. Under the elastic force of the first spring, the abutment plate moves up and has a gap between it and the boom body. Thus, when the monitoring mechanism moves, there is a gap between the monitoring probe and the boom body to prevent the coupling agent applied to the monitoring end of the monitoring probe from being scratched by the boom body. After moving to the monitoring position, the barrier plate rotates until the through hole connects with the exposure window of the magnetic block. At this time, the magnetic attraction between the magnetic block and the boom body is used to abut the abutment plate against the boom body to fix the monitoring mechanism at the monitoring position. In addition, during the monitoring process, repeated tapping of the boom body surface with a hammer artificially stimulates the generation of elastic stress waves on the structural surface, which can awaken micro-cracks and closed cracks to generate acoustic emission signals, making up for the problem that weak signals are difficult to capture under natural loads and improving the detection rate of micro-cracks. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the shifting mechanism of the present invention; Figure 3 This is the invention Figure 1 A partial structural diagram of the monitoring unit and cables; Figure 4 This is the invention Figure 3 A schematic diagram of the three-dimensional structure under partial cross-section; Figure 5 This is the invention Figure 3A partial sectional view of the structure from the front; Figure 6 This is a three-dimensional structural diagram of the monitoring mechanism and the cable after the abutment plate is removed, according to the present invention. Figure 7 This is a three-dimensional structural schematic diagram of another part of the monitoring mechanism of the present invention.
[0017] In the diagram: 1. Boom body; 2. Monitoring mechanism; 201. Data cable; 21. Clamp; 22. Guide post; 221. First spring; 23. Sleeve; 24. End cap; 25. Housing; 26. Abutment plate; 261. Locking post; 27. Monitoring probe; 271. Lower retaining ring; 272. Upper retaining ring; 273. Second spring; 28. Barrier plate; 281. Through hole; 29. Magnetic block; 291. Clamping ring; 210. 211. Gear; 3. Displacement mechanism; 31. Cable; 32. Roller; 33. Take-up and undo drive; 34. Support; 35. Tension sensor; 36. Guide wheel; 301. Limiting roller; 302. Support frame; 303. Supporting roller; 4. Striking assembly; 41. Striking hammer; 42. Hammer rod; 43. Lifting rod; 44. Third spring; 45. Guide seat; 46. Cam; 47. Striking drive. Detailed Implementation
[0018] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0019] In the description of the embodiments of this application, it should be understood that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that the product of this application is usually placed in, or the orientation or positional relationship that is commonly understood by those skilled in the art. They are only used to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0020] like Figure 1 , Figure 4 As shown, the present invention provides an acoustic emission monitoring device for cracks in a crane boom, comprising: The shifting mechanism 3 is disposed on the boom body 1. The shifting mechanism 3 includes a cable 31 and a take-up and extend assembly. The output end of the take-up and extend assembly is connected to the cable 31. The cable 31 is in a taut state. The extension direction of the cable 31 is parallel to the extension direction of the boom body 1. The monitoring mechanism 2 is installed on the cable 31. The monitoring mechanism 2 includes a monitoring probe 27, which is positioned facing the structural surface of the boom body 1. Driven by the retraction and extension assembly, the monitoring mechanism 2 moves with the retracted cable 31 to adjust the monitoring position of the monitoring probe 27 on the boom body 1.
[0021] like Figure 1 As shown, the boom body 1 is in a retracted state. During operation, the boom body 1 is in an extended long-distance state. At this time, the cable 31 can be unwound using the unwinding assembly, allowing it to unwind along with the extension distance of the boom body 1. During the unwinding process, the cable 31 is taut, allowing the monitoring mechanism 2 to move smoothly along with the unwinding cable 31. At this time, the monitoring probe 27 can be easily moved to the monitoring position without the need for manual climbing of the boom body 1. The operation is simple and the safety factor is high.
[0022] It should be noted that the monitoring probe 27 is an acoustic emission sensor, which captures the elastic wave signal released when cracks initiate and propagate on the outer surface of the boom body 1, i.e. the surface of the component. The coupling agent applied to the monitoring end of the monitoring probe 27, i.e. the monitoring end of the acoustic emission sensor, is intended to remove air and fill the tiny gaps at the interface, so that the high-frequency elastic stress wave (ultra-high frequency band, inaudible to the human ear) generated at the crack can be efficiently transmitted to the monitoring end of the acoustic emission sensor.
[0023] For example, see [link to relevant documentation]. Figure 2 The take-up and release assembly includes a take-up and release drive 33, a winding roller 32, and a steering roller. The two winding rollers 32 are rotatably mounted on a support 34, which is fixedly mounted on the fixed end of the boom body 1. The input end of the winding roller 32 is connected to the take-up and release drive 33, which is a drive motor. The two ends of the cable 31 are wound around the winding roller 32. The steering roller is rotatably mounted on the extension end of the boom body 1. The cable 31 between the two winding rollers 32 passes around the steering roller for steering. Thus, when the boom body 1 extends, the two winding rollers 32 are unwound synchronously, so that the cable 31 is pulled by the steering roller, and the monitoring mechanism 2 is pulled to the monitoring position by the cable 31.
[0024] It should be noted that further reading is required. Figure 2 A tension sensor 35 is installed on the support 34. A guide wheel 36 is fixedly installed on the pulling end of the tension sensor 35. The guide wheel 36 is correspondingly arranged with the winding roller 32. The end of the cable 31 near the winding roller 32 passes around the corresponding guide wheel 36. The tension sensor 35 detects the traction force of the cable 31 through the guide wheel 36 to indirectly reflect the tension of the cable 31. If the cable 31 becomes slack, the tension of the cable 31 can also be adjusted by winding the cable 31 around the winding roller 32.
[0025] For example, see [link to relevant documentation]. Figure 4The monitoring mechanism 2 further includes a first spring 221, a housing 25, magnetic blocks 29, a barrier plate 28, and a contact plate 26. An end cap 24 is fixedly installed on the upper end of the housing 25, and a sleeve 23 is fixedly installed on the upper end of the end cap 24. The sleeve 23 is slidably mounted on a guide post 22. The outer end of the guide post 22 is fixedly mounted on a cable 31 via a clamp 21. The portion of the guide post 22 located inside the sleeve 23 is fitted with the first spring 221. The monitoring probe 27 is installed inside the housing 25. Multiple magnetic blocks 29 are distributed around the monitoring probe 27 and fixedly installed inside the housing 25. A contact plate 26 is fixedly installed at the end of the housing 25 away from the end cap 24. The barrier plate 28 is rotatably mounted inside the contact plate 26. A through hole 281 is opened on the barrier plate 28, corresponding to the magnetic blocks 29. A toothed ring is fixedly installed on the periphery of the barrier plate 28. Figure 6 As shown, the gear ring meshing transmission has a gear 210, and the input end of the gear 210 is connected to a blocking drive component 211. For example, the blocking drive component 211 is a drive motor. Before the monitoring probe 27 performs detection, under the drive of the blocking drive component 211, the blocking plate 28 rotates until the exposed window of the magnetic block 29 is not connected to the through hole 281. It should be noted that the exposed window of the magnetic block 29 is an opening on the housing 25, which is correspondingly set with the magnetic block 29. At this time, the blocking plate 28 blocks the magnetic lines of force applied by the magnetic block 29 to the boom body 1. However, the blocking here is not cutting off the magnetic force, but rather significantly weakening the magnetic attraction force on the outside of the blocking plate 28. At this time, the elastic force of the first spring 221 is sufficient to overcome the magnetic attraction force between the blocking plate 28 and the boom body 1. That is, under the action of the elastic force of the first spring 221, the sleeve 23 slides upward along the guide post 22. At this time, the abutment plate 26 moves upward synchronously and has a gap between it and the boom body 1, so that when the monitoring mechanism 2 moves with the cable 31, the monitoring probe 27 and the boom body 1 do not generate friction, thereby preventing the coupling agent applied to the monitoring end of the monitoring probe 27 from being scratched by the boom body 1; when the monitoring probe 27 moves to the monitoring position, under the drive of the blocking drive 211, the blocking plate 28 rotates until the exposed window hole of the magnetic block 29 is connected to the through hole 281. At this time, under the magnetic attraction of the magnetic block 29, the abutment plate 26 abuts against the surface of the boom body 1, and with the help of the magnetic attraction of the magnetic block 29, the monitoring probe 27 is relatively fixed at the monitoring position of the boom body 1.
[0026] It should be noted that the magnetic block 29 is made of permanent magnet, while the barrier plate 28 is made of iron. The abutment plate 26 of the rotation constraint barrier plate 28 is made of a non-magnetic material, such as aluminum, aluminum alloy, copper, or non-metallic material. (See further details...) Figure 4 and Figure 5The magnetic block 29 is inserted into the housing 25, and a retaining ring 291 is embedded at the insertion port to prevent the magnetic block 29 from coming out. Furthermore, under the constraint of the abutment plate 26, even when the barrier plate 28 rotates to the point where the exposed window hole of the magnetic block 29 is not connected to the through hole 281, there is a gap between the barrier plate 28 and the magnetic block 29. Compared to the case of direct contact, the gap in the middle space prevents the magnetic block 29 from sticking to the barrier plate 28, so as to fully block the transmission of magnetic attraction force to the outside of the barrier plate 28.
[0027] For example, see [link to relevant documentation]. Figure 5 The monitoring end of the monitoring probe 27 is located outside the housing 25. An upper retaining ring 272 is provided on the inner edge of the monitoring probe 27. A lower retaining ring 271 is also provided on the housing 25. The lower retaining ring 271 is located below the upper retaining ring 272. The monitoring probe 27 slides with the housing 25 through the upper retaining ring 272 and the lower retaining ring 271. The upper retaining ring 272 and the lower retaining ring 271 limit the monitoring probe 27 from sliding out of the housing 25. A second spring 273 is fixedly installed at the upper end of the upper retaining ring 272. Before the monitoring probe 27 performs detection, the lower end face of the monitoring probe 27 in the initial position is lower than the lower end face of the abutment plate 26. Thus, under the action of magnetic attraction, before the abutment plate 26 abuts against the surface of the boom body 1, the monitoring probe 27 abuts against the surface of the boom body 1 first, and when the abutment plate 26 abuts against the surface of the boom body 1, the elastic force of the second spring 273 is used to ensure that the abutment between the monitoring probe 27 and the surface of the boom body 1 is secure.
[0028] For example, see [link to relevant documentation]. Figure 3 Multiple support frames 302 are also installed on the cable 31 located between the clamp 21 and the fixed end of the boom body 1. Limiting rollers 301 are rotatably installed on the support frames 302. The cable 31 passes through the pair of limit rollers 301 and rubs against the limit rollers 301. Support rollers 303 are also rotatably installed on the support frames 302. The data line 201 of the monitoring probe 27 is attached to the support rollers 303. Thus, when the monitoring mechanism 2 adjusts the monitoring position, the support rollers 303 ensure that the data line 201 is pulled out or retracted in an orderly manner, and will not get tangled or knotted with the cable 31 or the boom body 1. In addition, the support rollers 303 are in rolling contact, which greatly reduces the risk of wear on the outer sheath of the data line 201 and breakage of the core wire.
[0029] For example, see [link to relevant documentation]. Figure 3 and Figure 7The invention also includes a striking component 4, which comprises a striking hammer 41, a hammer rod 42, and a striking drive component. A guide seat 45 is fixedly installed on the outside of the housing 25. The hammer rod 42 is vertically slidably installed in the guide seat 45. The striking hammer 41 is fixedly disposed at one end of the hammer rod 42 extending into the guide seat 45. The output end of the striking drive component is connected to the hammer rod 42 for driving the hammer rod 42 to slide vertically back and forth. By repeatedly striking the surface of the boom body 1 with the striking hammer 41, elastic stress waves are artificially stimulated on the structural surface, which can awaken micro-cracks and closed cracks to generate acoustic emission signals, thus compensating for the problem of weak signals being difficult to capture under natural loads and improving the detection rate of micro-cracks.
[0030] For example, see [link to relevant documentation]. Figure 7 The striking drive assembly includes a striking drive component 47, a cam 46, a lifting rod 43, and a third spring 44. The upper end of the hammer rod 42 is fixedly connected to the third spring 44, and the side of the hammer rod 42 is fixedly connected to the lifting rod 43. The output end of the striking drive component 47 is drivenly connected to the cam 46, which is rotatably mounted in the guide seat 45. The cam 46 and the lifting rod 43 are in frictional contact. For example, the striking drive component 47 is a motor, and the cam 46 is an asymptotic wheel. When the lifting rod 43 is lifted and suddenly released, under the reset action of the compressed third spring 44, the hammer rod 42 drives the striking hammer 41 to move up and down reciprocally, so as to realize the repeated striking of the surface of the boom body 1 by the striking hammer 41.
[0031] Continue reading Figure 7 The side of the housing 25 and the side of the abutment plate 26 are respectively fixedly provided with ear plates. The ear plates are arranged in pairs, and the paired ear plates are fixedly connected by locking pins 261 to firmly limit the position between the housing 25 and the abutment plate 26.
[0032] It should be noted that, in use, the crane boom crack acoustic emission monitoring device and method, for the extended boom body 1, through the drive of the two retraction drive components 33, the two winding rollers 32 rotate synchronously, so that the cable 31 is unwound under the traction of the steering roller on the extended end of the boom body 1, and after the boom body 1 is extended to the position, the cable 31 is tightened under the tightening of the winding rollers 32. When monitoring is required, the monitoring mechanism 2 on the cable 31 is moved by the unwinding roller 32 on one side and the winding roller 32 on the other side. During the movement, the barrier plate 28 rotates until the exposed window of the magnetic block 29 is not connected to the through hole 281. At this time, under the action of the first spring 221, there is a gap between the abutment plate 26 and the boom body 1, so that the coupling agent applied to the monitoring end of the monitoring probe 27 will not be scratched. After the monitoring probe 27 moves to the monitoring position, the gear 210 meshes with the transmission gear ring through the barrier drive component 211, causing the barrier plate 28 to rotate until the through hole 281 connects with the window hole of the magnetic block 29. At this time, the magnetic block 29 generates a magnetic attraction force on the boom body 1, dragging the abutment plate 26 to abut the surface of the boom body 1, positioning the monitoring mechanism 2 in the monitoring position, so that the monitoring probe 27 contacts the boom body 1 through the coupling agent to perform crack monitoring. Furthermore, during monitoring, repeated tapping of the boom body 1 with the hammer 41 artificially stimulates the elastic stress wave generated on the structural surface, which can awaken the acoustic emission signals of micro-cracks and closed cracks, making up for the problem that weak signals are difficult to capture under natural loads and improving the detection rate of micro-cracks. After crack monitoring at one location is completed, the barrier drive 211 drives the gear 210 to mesh with the transmission gear ring, causing the barrier plate 28 to rotate until the exposed window hole of the magnetic block 29 is no longer connected to the through hole 281, causing the abutment plate 26 to move upward to disengage from the boom body 1, so as to perform crack monitoring at the next location.
[0033] In another embodiment, the present invention also provides a method for monitoring acoustic emission of cracks in a crane boom, the method comprising the following steps: The monitoring unit 2 is installed on the taut cable 31; The cable 31 is unwound by the unwinding assembly. The taut cable 31 is unwound along the extension direction of the boom body 1. The cable 31 drives the monitoring mechanism 2 to move in the same direction until the monitoring probe 27 is in the monitoring position, so as to monitor the cracks in the boom body 1.
[0034] This method eliminates the need for manual climbing, especially for long-distance telescopic boom bodies 1. Simply unwind the cable 31 using the rewinding component to move the monitoring mechanism 2 along the extension direction of the boom body 1 to the monitoring position. The operation is simple, requires no manual climbing, and has a high safety factor.
[0035] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.
Claims
1. A device for monitoring acoustic emission of cracks in the boom of crane machinery, characterized in that, include: A shifting mechanism is mounted on the boom body. The shifting mechanism includes a cable and a retraction assembly. The output end of the retraction assembly is connected to the cable, which is in a taut state. The extension direction of the cable is parallel to the extension direction of the boom body. A monitoring mechanism is installed on the cable. The monitoring mechanism includes a monitoring probe, which is positioned facing the structural surface of the boom body. Driven by the retraction and extension assembly, the monitoring mechanism moves with the retracted cable to adjust the monitoring position of the monitoring probe on the boom body. The monitoring mechanism further includes a first spring, a housing, magnetic blocks, a barrier plate, and a contact plate. An end cap is fixedly installed at the upper end of the housing, and a sleeve is fixedly installed at the upper end of the end cap. The sleeve is slidably installed on a guide post, and the outer end of the guide post is fixedly installed on a cable by a clamp. The first spring is sleeved on the part of the guide post located inside the sleeve. The monitoring probe is installed inside the housing. Multiple magnetic blocks are distributed around the monitoring probe and fixedly installed inside the housing. A contact plate is fixedly installed at the end of the housing away from the end cap. The barrier plate is rotatably installed inside the contact plate. A through hole is opened on the barrier plate, and the through hole is corresponding to the magnetic block. A toothed ring is fixedly installed around the periphery of the barrier plate. The toothed ring meshes with a gear, and the input end of the gear is connected to a barrier drive component. Before the monitoring probe performs detection, the barrier plate rotates under the drive of the barrier drive component until the exposed window hole and the through hole of the magnetic block are not connected; when the monitoring probe moves to the monitoring position, the barrier plate rotates under the drive of the barrier drive component until the exposed window hole and the through hole of the magnetic block are connected, and the abutment plate abuts against the surface of the boom body.
2. The acoustic emission monitoring device for cracks in a crane boom according to claim 1, characterized in that, The take-up and take-down assembly includes a take-up and take-down drive, a winding roller, and a steering roller. Two winding rollers are rotatably mounted on a support, which is fixedly mounted on the fixed end of the boom body. The input end of the winding roller is connected to the take-up and take-down drive. Both ends of the cable are wound around the winding roller. The steering roller is rotatably mounted on the extended end of the boom body. The cable between the two winding rollers passes around the steering roller for steering.
3. The acoustic emission monitoring device for cracks in a crane boom according to claim 2, characterized in that, A tension sensor is installed on the support, and a guide wheel is fixedly provided at the tension end of the tension sensor. The guide wheel is correspondingly provided with the roller, and the end of the cable near the roller passes around the corresponding guide wheel.
4. The acoustic emission monitoring device for cracks in a crane boom according to claim 1, characterized in that, The monitoring end of the monitoring probe is located outside the housing. An upper retaining ring is provided on the inner edge of the monitoring probe. A lower retaining ring is also provided on the housing. The lower retaining ring is located below the upper retaining ring. The monitoring probe slides with the housing through the upper and lower retaining rings. A second spring is fixedly installed at the upper end of the upper retaining ring. Before the monitoring probe performs detection, the lower end face of the monitoring probe in the initial position is lower than the lower end face of the abutment plate.
5. The acoustic emission monitoring device for cracks in a crane boom according to claim 4, characterized in that, Multiple support frames are also installed on the cable between the clamp and the fixed end of the boom body. Limit rollers are rotatably installed on the support frames. The cable passes through the pair of limit rollers and rubs against the limit rollers. Support rollers are also rotatably installed on the support frames. The data line of the monitoring probe is connected to the support roller.
6. The acoustic emission monitoring device for cracks in a crane boom according to claim 5, characterized in that, It also includes a striking assembly, which includes a striking hammer, a hammer rod, and a striking drive assembly. A guide seat is fixedly installed on the outside of the housing. The hammer rod is vertically slidably installed in the guide seat. A striking hammer is fixedly installed at one end of the hammer rod that extends to the guide seat. The output end of the striking drive assembly is connected to the hammer rod for driving the hammer rod to slide vertically back and forth.
7. The acoustic emission monitoring device for cracks in a crane boom according to claim 6, characterized in that, The striking drive assembly includes a striking drive component, a cam, a lifting rod, and a third spring. The upper end of the hammer rod is fixedly connected to the third spring, and the side of the hammer rod is fixedly connected to the lifting rod. The output end of the striking drive component is driven by a cam, and the cam and the lifting rod are in frictional contact.
8. The acoustic emission monitoring device for cracks in a crane boom according to claim 6, characterized in that, The side of the housing and the side of the abutment plate are respectively fixedly provided with ear plates, which are arranged in pairs and are fixedly connected by locking pins.
9. A method for using the acoustic emission monitoring device for cracks in the boom of a crane as described in claim 1, characterized in that, Includes the following steps: The monitoring equipment was installed on a taut cable; The cable is unwound using the take-up and unwind assembly. The taut cable is unwound along the extension direction of the boom body, and the cable drives the monitoring mechanism to move in the same direction until the monitoring probe is in the monitoring position to monitor cracks in the boom body.