A drop hammer impact testing device for anchor bolts or anchor cables

Abstract

A drop hammer impact testing device for anchor bolts or anchor cables includes a lifting mechanism, a main frame, a hammer-grabbing device, a guide structure, a connecting structure, an impact force transmission mechanism, a hammer body, and a lifting rod. The main frame has a top plate at its top and a bottom plate at its bottom. The guide structure is located within the main frame, and the lifting mechanism is located on the upper surface of the top plate. The output end of the lifting mechanism is connected to the hammer-grabbing device, and the hammer body is located at the bottom of the hammer-grabbing device. Both the hammer-grabbing device and the hammer body are slidably fitted with the guide structure. This drop hammer impact testing device for anchor bolts or anchor cables solves the problem that the testing of anchor bolt or anchor cable support materials in related technologies focuses on static load testing, resulting in a lack of means to test the quality of anchor bolt or anchor cable support materials under impact loads.

Description

Technical Field

[0001] This utility model belongs to the field of anchor bolt or anchor cable impact absorption energy testing technology, and in particular relates to a drop hammer impact test device for anchor bolts or anchor cables. Background Technology

[0002] Rockbursts, a major hazard in deep coal mining, are characterized by their suddenness and destructive power, often causing serious casualties and significant property losses. As mining depths extend to the kilometer level, the complex mechanical environment of the rock mass—characterized by "three highs and one disturbance" (high ground stress, high osmotic pressure, high temperature, and strong mining disturbance)—significantly exacerbates the risk of rockbursts.

[0003] In rockburst prevention systems, anchor bolt or cable support systems play a crucial role through active support mechanisms. Therefore, it is particularly important to quantitatively evaluate the rockburst resistance performance of anchor bolts or cables and to establish a quality evaluation system for anchor bolts or cables from the perspective of rockburst energy absorption. However, because the testing of anchor bolt or cable support materials in related technologies focuses on static load tests, there is a lack of methods for quality testing of anchor bolt or cable support materials under impact loads. Summary of the Invention

[0004] In view of this, the present invention aims to at least partially solve one of the related technical problems.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A drop hammer impact test device for anchor bolts or anchor cables includes a lifting mechanism, a main frame, a hammer grabbing and lifting device, a guiding structure, a connecting structure, an impact force transmission mechanism, a hammer body, and a lifting rod.

[0007] The main frame has a top plate at the top and a bottom plate at the bottom.

[0008] The guide structure is set inside the main frame, the lifting mechanism is set on the upper surface of the top plate, the output end of the lifting mechanism is connected to the grabbing hammer device, the hammer body is set at the bottom of the grabbing hammer device, and both the grabbing hammer device and the hammer body are slidably engaged with the guide structure.

[0009] The top of the boom is connected to the lower end face of the top plate, the boom passes through the grabbing hammer device and the hammer body, and the bottom of the boom is detachably connected to the anchor rod or anchor cable through a connecting structure;

[0010] The impact transmission mechanism is provided at the bottom of the anchor rod or anchor cable. The impact transmission mechanism is detachably connected to the anchor rod or anchor cable and is used to bear the impact of the hammer.

[0011] Furthermore, the lifting mechanism includes a lifting chain and a lifting motor. The lifting motor drives the gripping hammer device to move up and down along the guide structure via the lifting chain. The lifting motor is located on the upper end face of the top plate.

[0012] Furthermore, the guide structure includes two column guide rails, which are arranged side by side inside the main frame. The top of the column guide rails is connected to the top plate, and the bottom of the column guide rails is connected to the bottom plate. The column guide rails slide in cooperation with the grabbing hammer device and the hammer body.

[0013] Furthermore, the lifting hammer device includes a lifting plate and a strong electromagnetic device. The lifting plate is connected to the output end of the lifting mechanism, the lifting rod passes through the lifting plate, and the strong electromagnetic device is disposed inside the lifting plate. The strong electromagnetic device attracts the hammer body when energized and releases the hammer body when de-energized.

[0014] Furthermore, the impact transmission mechanism includes an impact pad, an impact base, a fixed support plate, a locking sleeve, a detachable structure, two sliding structures, and two fixed structures.

[0015] The impact pad is disposed on the upper end surface of the impact base. The left and right ends of the impact base are provided with vertical bends. A sliding structure is provided on the outer side of each vertical bend. The sliding structure slides in cooperation with the column guide rail of the guide structure.

[0016] Two fixed structures are symmetrically arranged on the lower end face of the impact base. The locking sleeve is located below the middle part of the impact base. The fixed support plate is located directly above the locking sleeve. The middle part of the impact pad, the middle part of the impact base, and the fixed support plate are all provided with a first through hole that can cooperate with the hanger.

[0017] The inner wall of the locking sleeve is threaded with the anchor rod or anchor cable, and the lower part of the outer wall of the locking sleeve is provided with a thickened sleeve. The thickened sleeve is connected and fixed to the two fixed structures through the detachable structure.

[0018] Furthermore, the fixing structure includes an L-shaped support plate and a stiffening plate. The upper end face of the L-shaped support plate is connected to the impact base and the impact pad plate by bolts. The stiffening plate is located at the bent edge of the L-shaped support plate. The side end face of the L-shaped support plate is connected to the detachable structure.

[0019] Furthermore, the detachable structure includes two pins, both of which pass through the thickened sleeve and the L-shaped support plates of the two fixed structures.

[0020] Furthermore, the sliding structure includes a sliding sleeve and a mounting plate. The sliding sleeve is connected to the vertical bend through the mounting plate, and the interior of the sliding sleeve is slidably engaged with the column guide rail through a linear bearing.

[0021] Compared with the prior art, the drop hammer impact test device for anchor bolts or anchor cables described in this utility model has the following advantages:

[0022] 1. This mechanism, through the tight engagement of the vertical curved edges on both sides of the impact base with the linear bearings of the sliding sleeve along the column guide rail, constructs a vertically offset motion trajectory, completely eliminating the risk of device swaying or torsion caused by inertial off-center loading at the moment of impact; the threaded engagement between the inner wall of the locking sleeve and the anchor rod or anchor cable, supplemented by the rigid constraint of the pin penetrating the L-shaped support plate, disperses local impact stress by thickening the sleeve to prevent thread shear failure, and resists asymmetric bending moment impact with the reinforcement of the stiffening plate, ultimately achieving efficient and lossless transmission of hammer kinetic energy along the axis of the anchor rod or anchor cable, providing an interference-free mechanical environment for the study of the dynamic fracture behavior of the anchor rod or anchor cable.

[0023] 2. The detachable structure with pin connection allows the impact base and locking sleeve to form a quick-release module, greatly simplifying the replacement process of anchor rods or cables of different specifications; the composite pressure-bearing layer design of the impact pad and impact base significantly reduces the interference of stress wave reflection on the measurement signal by dissipating high-frequency shock wave energy in layers; the thickened design of the outer wall of the locking sleeve, combined with the stress diffusion structure of the stiffening plate, eliminates the risk of thread fatigue fracture in high-cycle impact tests from the root, providing reliable structural integrity guarantee for continuous impact testing. Attached Figure Description

[0024] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0025] Figure 1 This is a schematic diagram of a drop hammer impact test device for anchor bolts or anchor cables according to Embodiment 2 of this utility model;

[0026] Figure 2 This is a schematic diagram of the impact force transmission mechanism described in Embodiment 1 of this utility model;

[0027] Figure 3 This is a schematic diagram of the fixing structure described in Embodiment 1 of this utility model;

[0028] Figure 4 This is a front view of the impact force transmission mechanism described in Embodiment 1 of this utility model.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Lifting chain; 2. Grab and lift hammer device; 3. Connecting structure; 4. Anchor bolt or anchor cable; 5. Tray; 50. Impact pad; 51. Impact base; 52. Sliding structure; 53. L-shaped support plate; 54. Thickened sleeve; 55. Detachable structure; 56. Rib plate; 57. Fixed support plate; 6. Locking nut; 7. Lifting motor; 8. Hammer body; 9. Hanging rod; 10. Column guide rail; 11. Main frame. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other.

[0032] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Example 1

[0036] A drop hammer impact testing apparatus for anchor bolts or anchor cables, such as Figure 1As shown, it includes a lifting mechanism, a main frame 11, a grabbing hammer device 2, a guide structure, a connecting structure 3, an impact transmission mechanism, a hammer body 8, and a hanging rod 9; the main frame 11 has a top plate at the top and a bottom plate at the bottom; the guide structure is set inside the main frame 11, the lifting mechanism is set on the upper surface of the top plate, the output end of the lifting mechanism is connected to the grabbing hammer device 2, the bottom of the grabbing hammer device 2 is provided with the hammer body 8, and both the grabbing hammer device 2 and the hammer body 8 are slidably engaged with the guide structure; the top of the hanging rod 9 is connected to the lower surface of the top plate, the hanging rod 9 passes through the grabbing hammer device 2 and the hammer body 8, and the bottom of the hanging rod 9 is detachably connected to the anchor rod 4 through the connecting structure 3;

[0037] An impact transmission mechanism is provided at the bottom of the anchor rod 4. The impact transmission mechanism is detachably connected to the anchor rod 4 and is used to bear the impact of the hammer 8.

[0038] The lifting mechanism includes a lifting chain 1 and a lifting motor 7. The lifting motor 7 drives the grabbing hammer device 2 to move up and down along the guide structure through the lifting chain 1. The lifting motor 7 is located on the upper surface of the top plate.

[0039] The guide structure includes two column guide rails 10, which are arranged side by side inside the main frame 11. The top of the column guide rail 10 is connected to the top plate, and the bottom of the column guide rail 10 is connected to the bottom plate. The column guide rail 10 slides in cooperation with the grabbing hammer device 2 and the hammer body 8.

[0040] The lifting hammer device 2 includes a lifting plate and a strong electromagnetic device. The lifting plate is connected to the output end of the lifting mechanism. The lifting rod 9 passes through the lifting plate. The strong electromagnetic device is installed inside the lifting plate. When the strong electromagnetic device is energized, it attracts the hammer body 8. When the power is off, it releases the hammer body 8.

[0041] The lifting plate of the grabbing hammer device 2 is made of steel plate and is rectangular in shape. A circular through hole is opened in the middle of the plate. The diameter of the second through hole is 5-10mm larger than the outer diameter of the lifting rod 9. The strong electromagnetic device is a ring electromagnet, which is embedded in the lifting plate and distributed around the second through hole. Its wires are connected to an external power controller. When the electromagnet is de-energized, the generated strong magnetic field attracts the upper surface of the hammer body 8. When energized, it is demagnetized and the hammer body 8 falls freely.

[0042] The impact transmission mechanism includes an impact pad 50, an impact base 51, a fixed support plate 57, a locking sleeve, a detachable structure 55, two sliding structures 52, and two fixed structures. The impact pad 50 is located on the upper surface of the impact base 51. Vertical bends are provided at both the left and right ends of the impact base 51, and a sliding structure 52 is correspondingly provided on the outer side of each vertical bend. The sliding structure 52 slides in cooperation with the column guide rail 10 of the guide structure. The two fixed structures are symmetrically arranged on the lower surface of the impact base 51. The locking sleeve is located below the middle of the impact base 51, and the fixed support plate 57 is located directly above the locking sleeve. The middle of the impact pad 50, the middle of the impact base 51, and the fixed support plate 57 are all... The mechanism is equipped with a first through hole that can cooperate with the lifting rod 9. The vertical curved edges on both sides of the impact base 51 are tightly engaged with the linear bearings of the sliding sleeve along the column guide rail 10, which creates a vertically unbiased motion trajectory and completely eliminates the risk of device shaking or torsion caused by inertial off-center load at the moment of impact. The threaded engagement between the inner wall of the locking sleeve and the anchor rod 4 is supplemented by the rigid constraint of the pin penetrating the L-shaped support plate 53. The thickened sleeve 54 disperses the local impact stress to prevent thread shear failure. The bending section reinforced by the stiffening plate 56 resists the asymmetric bending moment impact. Finally, the kinetic energy of the hammer 8 is efficiently and non-destructively transmitted along the axis of the anchor rod 4, providing an interference-free mechanical environment for the study of the dynamic fracture behavior of the anchor rod 4.

[0043] The inner wall of the locking sleeve is threaded to the anchor rod 4, and the lower part of the outer wall of the locking sleeve is provided with a thickened sleeve 54. The thickened sleeve 54 is connected and fixed to two fixed structures through a detachable structure 55.

[0044] The fixed structure includes an L-shaped support plate 53 and a stiffening plate 56. The upper end face of the L-shaped support plate 53 is connected to the impact base 51 and the impact pad 50 by bolts. The stiffening plate 56 is located at the bent edge of the L-shaped support plate 53. The side end face of the L-shaped support plate 53 is connected to the detachable structure 55.

[0045] The detachable structure 55 includes two pins, both of which pass through the thickened sleeve 54 and the L-shaped support plates 53 of the two fixed structures. The sliding structure 52 includes a sliding sleeve and a mounting plate. The sliding sleeve is connected to the vertical bend through the mounting plate, and the interior of the sliding sleeve is slidably engaged with the column guide rail 10 through a linear bearing. The detachable structure with pin connections allows the impact base 51 and the locking sleeve to form a quick-release module, greatly simplifying the replacement process of anchor rods 4 of different specifications. The composite pressure-bearing layer design of the impact pad 50 and the impact base 51 significantly reduces the interference of stress wave reflection on the measurement signal by dissipating high-frequency shock wave energy in layers. The thickened design of the outer wall of the locking sleeve, combined with the stress diffusion structure of the stiffening plate 56, fundamentally eliminates the risk of thread fatigue fracture in high-cycle impact tests, providing reliable structural integrity assurance for continuous impact testing.

[0046] The experimental setup also includes a data collection module for collecting experimental data and a computer module for processing the experimental data. The data collection module includes a laser displacement sensor for acquiring displacement data and a force sensor for acquiring impact force data; the force sensor is directly integrated into the impact pad 50 that bears the impact energy (zero transmission loss in impact force measurement); the laser displacement sensor focuses on the lower free section of the anchor rod or anchor cable (avoiding interference from the anchoring section and capturing pure rod deformation); a high-speed camera orthogonally monitors the dynamic expansion of the anchor rod or anchor cable.

[0047] How this example works

[0048] S1: Insert the end of the anchor rod 4 into the locking sleeve 54 for pre-tightening. The impact pad 50 of the impact base 51 is connected to the column guide rail 10 through the vertical bend and the linear bearing of the sliding structure 52. The pin passes through the L-shaped support plate 53 and the thickened sleeve 54 to lock the detachable structure 55. Simultaneously calibrate the laser displacement sensor to focus on the lower end of the free section of the anchor rod 4 and the high-speed camera for orthogonal monitoring. The computer module initializes the data link.

[0049] S2: The top of the anchor rod 4 is screwed to the bottom of the hanger 9 through the connecting structure 3 of the connecting sleeve structure. The top of the hanger 9 is fixed to the top plate of the main frame 11. The gap between the sliding structure 52 and the column guide rail 10 is adjusted to ensure that the impact base 51 does not deviate or slide.

[0050] S3: The lifting motor 7 drives the lifting chain 1 to pull the lifting hammer device 2 to rise. The strong electromagnetic device is energized to attract the hammer body 8 to the set height. The laser displacement sensor calibrates the initial coordinates of the free section of the anchor rod 4 and starts the high-speed camera to pre-record.

[0051] S4: The strong electromagnetic device is de-energized and releases the hammer 8. The hammer 8 falls freely along the rod 9 and the column guide rail 10 to impact the impact pad 50. The impact force is transmitted through the impact base 51 → locking sleeve 54 → anchor rod 4 axis. The laser displacement sensor captures the pure deformation data of the anchor rod 4, and the high-speed camera records the dynamic expansion of the crack.

[0052] S5: Lifting motor 7 lifts hammer 8 back, computer module integrates peak load, displacement time history curve and crack sequence of impact pad 50 force sensor, outputs fracture characteristic parameters of anchor rod 4, disassembles pin shaft to replace test piece.

[0053] Example 2

[0054] S1: Pass the bottom of the anchor cable 4 through the tray 5 and pre-tighten it with the locking nut 6. The top of the anchor cable 4 is fixed to the bottom of the hanger 9 by the connection structure 3 of the anchor structure. The laser displacement sensor focuses on the lower end of the free section of the anchor cable 4. The high-speed camera orthogonally monitors the vibration of the steel strand.

[0055] S2: The top of the boom 9 is fixed to the top plate of the main frame 11. The sliding structure 52 is removed so that the tray 5 directly bears the impact, verifying the signal path of the force sensor.

[0056] S3: The lifting motor 7 drives the lifting chain 1 to pull the lifting hammer device 2 and raise the hammer body 8 to the set height. The strong electromagnetic device is energized to attract the hammer body 8 and simultaneously calibrates the initial prestress state of the anchor cable 4.

[0057] S4: The strong electromagnetic device is de-energized and releases the hammer 8. The lower impact block of the hammer 8 strikes the surface of the tray 5 vertically. The impact force is transmitted to the free section of the anchor cable 4 through the locking nut 6. The laser displacement sensor captures the vibration displacement of the steel strand, and the high-speed camera records the prestress fluctuation and sheath rupture process.

[0058] S5: Lifting motor 7 lifts back hammer body 8, computer module analyzes tray 5 force sensor impact waveform, free segment vibration spectrum and prestress loss rate, disassembles locking nut 6 and replaces anchor cable 4 test piece.

[0059] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A drop hammer impact testing device for an anchor rod or cable, characterized by: It includes a lifting mechanism, a main frame (11), a grabbing and lifting hammer device (2), a guiding structure, a connecting structure (3), an impact force transmission mechanism, a hammer body (8), and a lifting rod (9); The main frame (11) has a top plate at the top and a bottom plate at the bottom. The guide structure is set inside the main frame (11), the lifting mechanism is set on the upper surface of the top plate, the output end of the lifting mechanism is connected to the grabbing hammer device (2), the bottom of the grabbing hammer device (2) is provided with the hammer body (8), and both the grabbing hammer device (2) and the hammer body (8) are slidably engaged with the guide structure. The top of the boom (9) is connected to the lower end face of the top plate. The boom (9) passes through the grab hammer device (2) and the hammer body (8). The bottom of the boom (9) is detachably connected to the anchor rod (4) or anchor cable through the connecting structure (3). The impact transmission mechanism is provided at the bottom of the anchor rod (4) or anchor cable. The impact transmission mechanism is detachably connected to the anchor rod (4) or anchor cable. The impact transmission mechanism is used to bear the impact of the hammer (8). The impact transmission mechanism includes an impact pad (50), an impact base (51), a fixed support plate (57), a locking sleeve, a detachable structure (55), two sliding structures (52), and two fixed structures. The impact pad (50) is disposed on the upper end surface of the impact base (51). The left and right ends of the impact base (51) are provided with vertical bends. A sliding structure (52) is provided on the outer side of each vertical bend. The sliding structure (52) is slidably engaged with the column guide rail (10) of the guide structure. Two fixed structures are symmetrically arranged on the lower end face of the impact base (51). The locking sleeve is located below the middle part of the impact base (51). The fixed support plate (57) is located directly above the locking sleeve. The middle part of the impact pad (50), the middle part of the impact base (51) and the fixed support plate (57) are all provided with a first through hole that can cooperate with the hanger (9). The inner wall of the locking sleeve is threaded with the anchor rod (4) or the anchor cable. The lower part of the outer wall of the locking sleeve is provided with a thickened sleeve (54). The thickened sleeve (54) is connected and fixed to the two fixed structures through the detachable structure (55).

2. A drop hammer impact testing device for an anchor rod or cable according to claim 1, characterized in that: The lifting mechanism includes a lifting chain (1) and a lifting motor (7). The lifting motor (7) drives the grabbing hammer device (2) to move up and down along the guide structure through the lifting chain (1). The lifting motor (7) is located on the upper surface of the top plate.

3. The drop hammer impact testing device for an anchor rod or cable according to claim 1, characterized in that: The guide structure includes two column guide rails (10), which are arranged side by side inside the main frame (11). The top of the column guide rail (10) is connected to the top plate, and the bottom of the column guide rail (10) is connected to the bottom plate. The column guide rail (10) slides in cooperation with the grabbing hammer device (2) and the hammer body (8).

4. The drop hammer impact testing device for an anchor rod or cable according to claim 1, characterized in that: The grabbing and lifting hammer device (2) includes a lifting plate and a strong electromagnetic device. The lifting plate is connected to the output end of the lifting mechanism. The lifting rod (9) passes through the lifting plate. The strong electromagnetic device is located inside the lifting plate. The strong electromagnetic device attracts the hammer body (8) when it is powered on and releases the hammer body (8) when it is powered off.

5. A drop hammer impact testing device for an anchor rod or cable according to any one of claims 1-4, characterized in that: The fixed structure includes an L-shaped support plate (53) and a stiffening plate (56). The upper end face of the L-shaped support plate (53) is connected to the impact base (51) and the impact pad (50) by bolts. The stiffening plate (56) is located at the bent edge of the L-shaped support plate (53). The side end face of the L-shaped support plate (53) is connected to the detachable structure (55).

6. A drop hammer impact testing device for an anchor rod or cable according to claim 5, wherein: The detachable structure (55) includes two pins, both of which pass through the thickened sleeve (54) and the two L-shaped support plates (53) of the fixed structure.

7. A drop hammer impact testing device for an anchor rod or cable according to claim 5, wherein: The sliding structure (52) includes a sliding sleeve and a mounting plate. The sliding sleeve is connected to the vertical bend through the mounting plate. The interior of the sliding sleeve is slidably engaged with the column guide rail (10) through a linear bearing.

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