Automatic rebound device of rebound hammer for highway tunnel concrete strength detection

Abstract

The application discloses a rebound hammer automatic rebound device for highway tunnel concrete strength detection, and belongs to the field of building engineering quality detection. The automatic rebound device comprises a shell, a rebounding rod inserted into one end of the shell, and an automatic rebound assembly connected with the rebounding rod. A limiting mechanism is arranged on the shell. The limiting mechanism comprises an annular limiting groove arranged on the outer side of the rebounding rod, a limiting ring axially moving on the annular limiting groove, and a cap sleeved on the rebounding rod and the limiting ring and threadedly connected with the bottom of the shell. The limiting ring is fixed on the bottom of the shell by the cap, so that axial displacement of the limiting ring is effectively prevented. The annular limiting groove on the outer side of the rebounding rod cooperates with the limiting ring, so that the axial movement range of the rebounding rod is accurately limited, the rebounding rod is prevented from being separated from the shell due to inertial action in the automatic rebounding process, the position of the rebounding rod is stabilized, repeated installation and debugging operations in the detection process are reduced, and the detection efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of building engineering quality testing technology, specifically an automatic rebound device for testing the concrete strength of highway tunnels. Background Technology

[0002] With the increasing demands for refined quality control in modern construction engineering, non-destructive testing (NDT) technology, due to its advantages of both efficiency and completeness, has been widely used in concrete strength testing in projects such as highway tunnels. The rebound method, a typical NDT technique, uses a rebound hammer to non-destructively measure concrete strength. Its basic principle is as follows: a spring-driven hammer strikes a vertical impact bar perpendicular to the concrete surface with constant kinetic energy. Localized concrete deformation absorbs some energy, and the remaining energy is converted into the rebound kinetic energy of the hammer. When the rebound kinetic energy is completely converted into potential energy, the maximum rebound distance of the hammer is displayed as a rebound value, from which the concrete strength can be calculated. This method, due to its ease of operation and controllable cost, has become a commonly used technique for on-site testing in engineering projects.

[0003] In practical operation, existing rebound hammers rely on the operator's two hands working together: one hand holds the front of the instrument while the other presses down on the rear to complete the impact. The impact rod lacks an effective limiting mechanism during the rebound process. If the operating force or angle is incorrect, the impact rod can easily detach from the rebound hammer body due to inertia, requiring frequent reinstallation and adjustment. This problem not only increases operational complexity but also significantly reduces testing efficiency. This drawback is particularly pronounced in large-scale tunnel engineering inspections, where the time-consuming nature of repeated disassembly and reassembly further exacerbates the issue, making it difficult to meet the demands of efficient testing in modern engineering projects.

[0004] Therefore, this application provides an automatic rebound device for testing the concrete strength of highway tunnels using a rebound hammer, in order to solve the above-mentioned problems. Utility Model Content

[0005] This application provides an automatic rebound device for testing the concrete strength of highway tunnels, aiming to solve the problems mentioned in the background art, such as the rebound bar of existing rebound hammers easily detaching from the housing during the rebound process due to the lack of a limiting mechanism, resulting in low testing efficiency.

[0006] To achieve the above objectives, this application provides the following technical solution: an automatic rebound device for testing the concrete strength of highway tunnels, comprising a housing, an impact rod inserted into one end of the housing, and an automatic rebound assembly connected to the impact rod;

[0007] To prevent the impact rod from detaching from the housing during automatic rebound, the housing is equipped with a limiting mechanism for axial movement of the impact rod. This limiting mechanism includes an annular limiting groove on the outer side of the impact rod, a limiting ring that moves axially within the annular limiting groove, and a cap fitted onto the impact rod and the limiting ring and threaded to the bottom of the housing to secure the limiting ring to the bottom of the housing. The cap fits over the impact rod and the limiting ring and is threaded to the bottom of the housing to press and fix the limiting ring. When the impact rod moves axially under impact or rebound force, the limiting ring engages with the edge of the annular limiting groove, restricting the axial movement of the impact rod to its limit position, ensuring it can only move within the guide space formed by the limiting ring and the housing, thus preventing it from detaching from the housing.

[0008] Preferably, to reduce the impact between the top of the limiting ring and the bottom wall of the annular limiting groove, a buffer pad is fixedly connected to the top of the limiting ring. The buffer pad effectively absorbs the impact energy between the bottom wall of the annular limiting groove and the top of the limiting ring when the impact rod rebounds to its extreme position, reducing noise and component wear caused by rigid collisions, extending the service life of the limiting mechanism, and improving the smoothness of the impact rod's rebound process, thus avoiding fluctuations in detection data caused by severe impacts.

[0009] Preferably, to facilitate the rotation of the cap, several protruding rods are circumferentially fixedly connected to the outer side wall of the cap. The evenly distributed protruding rods on the outer side wall of the cap provide a convenient force-applying structure for the operator, allowing for quick rotation of the cap without the need for special tools. This enables the installation and removal of the limit ring, significantly improving the convenience of equipment maintenance and debugging.

[0010] Preferably, for automatic rebound of the impact rod: the automatic rebound assembly includes a fixed sleeve slidably sleeved on the impact rod and inserted into the bottom of the housing, a central guide rod inserted into the top of the impact rod, an impact hammer sleeved on the central guide rod, and an impact spring sleeved on the central guide rod. The two ends of the impact spring are respectively fixedly connected between the impact hammer and the fixed sleeve. A guide baffle is fixedly connected to the top of the central guide rod, and the guide baffle is provided with a locking element for engaging with the impact hammer. The automatic rebound assembly, through the storage and release of the elastic potential energy of the impact spring, combined with the automatic release mechanism of the locking element, realizes the automatic rebound function of the impact rod, improving the automation level of the detection process and the stability of the rebound energy, and avoiding detection errors caused by uneven manual operation force.

[0011] Preferably, the locking component includes a through groove formed in the guide baffle, a U-shaped locking plate hinged in the through groove, a fastening spring disposed inside the through groove that abuts against the U-shaped locking plate, and a T-shaped sleeve fixedly connected to the top of the impact hammer, the top of the T-shaped sleeve engaging with the bottom of the U-shaped locking plate. The locking component, through the engagement of the U-shaped locking plate and the T-shaped sleeve, ensures that the impact hammer and the guide baffle move synchronously during the charging process of the spring-loaded spring, and achieves stable engagement through the elastic force of the fastening spring when reaching the preset position, preventing accidental disengagement during the charging process; simultaneously, the precise triggering upon disengagement ensures stable output of rebound energy, improving the consistency and reliability of the test results.

[0012] Preferably, the automatic rebound assembly further includes a pressure spring disposed on the top of the housing, the bottom of which abuts against the top of the guide baffle. A tail cap is threadedly connected to the top of the housing, and a tapered tube adapted to the U-shaped clamp is fixedly connected to the bottom of the tail cap. The larger diameter of the tapered tube faces the guide baffle, and the smaller diameter faces the tail cap. The combined use of the pressure spring and the tapered tube provides a stable triggering mechanism for the release of the U-shaped clamp, ensuring that the spring-loaded lever accurately releases the potential energy of the spring-loaded tension spring when it is pressed and moved to a specific position. This avoids rebound failure or energy instability caused by manual operation position deviation, improving the reliability and intelligence of the automatic rebound device.

[0013] This application, by setting a limiting mechanism on the housing and using a cap to fix the limiting ring to the bottom of the housing, can effectively prevent the limiting ring from axial displacement. The limiting ring cooperates with the annular limiting groove on the outside of the impact rod to accurately limit the axial movement range of the impact rod, preventing it from detaching from the housing due to inertia during automatic rebound, thereby ensuring the stability of the impact rod position, reducing repeated installation and debugging operations during the testing process, and significantly improving the efficiency of concrete strength testing in highway tunnels.

[0014] This application effectively absorbs the impact energy between the bottom wall of the annular limiting groove and the top of the limiting ring when the impact rod rebounds to its limit position by fixing a buffer pad to the top of the limiting ring. This reduces noise and component wear caused by rigid collisions, extends the service life of the limiting mechanism, and improves the stability of the impact rod's rebound process, thus avoiding fluctuations in detection data caused by severe impacts.

[0015] This application's automatic rebound assembly utilizes the elastic potential energy storage and release of the spring-loaded spring, combined with the automatic release mechanism of the latching component, to achieve the automatic rebound function of the impact rod. This improves the automation level of the detection process and the stability of the rebound energy, avoiding detection errors caused by uneven manual operation force. The combined use of the pressure spring and the tapered tube provides a stable triggering mechanism for the release of the U-shaped latch, ensuring that the impact rod accurately releases the potential energy of the spring-loaded spring when it moves to a specific position under pressure. This avoids rebound failure or energy instability caused by manual operation position deviation, improving the reliability and intelligence of the automatic rebound device. Attached Figure Description

[0016] Figure 1 A schematic diagram of the automatic rebound device for testing the concrete strength of highway tunnels.

[0017] Figure 2 for Figure 1 The structural sectional view in the middle;

[0018] Figure 3 Exploded view of the structure connecting the limiting mechanism and the impact rod to the extrusion housing;

[0019] Figure 4 Exploded view of the structure connecting the firing rod and the fixed sleeve;

[0020] Figure 5 This is a diagram showing the internal structure of shell 1;

[0021] Figure 6 This is a schematic diagram of the snap-fit ​​connector.

[0022] In the picture:

[0023] 1. Housing; 2. Impact rod; 3. Automatic rebound assembly; 31. Fixing sleeve; 32. Central guide rod; 33. Impact hammer; 34. Impact spring; 35. Guide baffle; 36. Snap-fit ​​component; 361. U-shaped clamp; 362. Fastening spring; 363. T-shaped sleeve; 37. Compression spring; 38. Tail cap; 39. Tapered tube; 4. Limiting mechanism; 41. Annular limiting groove; 42. Limiting ring; 421. Buffer pad; 43. Cap; 431. Protruding rod. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0025] This embodiment provides an automatic rebound device for testing the concrete strength of highway tunnels, such as... Figure 1-6 As shown, the automatic rebound device includes a housing 1, a spring rod 2 inserted into one end of the housing 1, and an automatic rebound assembly 3 connected to the spring rod 2;

[0026] To prevent the impact rod 2 from detaching from the housing 1 during automatic rebound, the housing 1 is equipped with a limiting mechanism 4 for axial movement of the impact rod 2. The limiting mechanism 4 includes an annular limiting groove 41 on the outer side of the impact rod 2, a limiting ring 42 that moves axially within the annular limiting groove 41, and a cap 43 that is fitted onto the impact rod 2 and the limiting ring 42 and threaded to the bottom of the housing 1 to fix the limiting ring 42 to the bottom of the housing 1. By providing the limiting mechanism 4 on the housing 1 and fixing the limiting ring 42 to the bottom of the housing 1 using the cap 43, axial displacement of the limiting ring 42 can be effectively prevented. The limiting ring 42, in conjunction with the annular limiting groove 41 on the outer side of the impact rod 2, can precisely limit the axial movement range of the impact rod 2, preventing it from detaching from the housing 1 due to inertia during automatic rebound. This ensures the stability of the impact rod 2's position, reduces repeated installation and adjustment operations during testing, and significantly improves the efficiency of concrete strength testing in highway tunnels. The cap 43 is fitted over the outside of the impact rod 2 and the limiting ring 42, and the limiting ring 42 is pressed and fixed by the threaded connection with the bottom of the housing 1. When the impact rod 2 moves axially under the impact force or the rebound force, the limiting ring 42 is embedded in the edge area of ​​the annular limiting groove 41, which restricts the axial movement limit position of the impact rod 2, so that it can only move within the guide space formed by the limiting ring 42 and the housing 1, thereby preventing it from detaching from the housing 1.

[0027] To reduce the impact between the top of the limiting ring 42 and the inner bottom wall of the annular limiting groove 41, a buffer pad 421 is fixedly connected to the top of the limiting ring 42. The buffer pad 421 effectively absorbs the impact energy between the inner bottom wall of the annular limiting groove 41 and the top of the limiting ring 42 when the impact rod 2 rebounds to its limit position. This reduces noise and component wear caused by rigid collisions, extends the service life of the limiting mechanism 4, and improves the smoothness of the rebound process of the impact rod 2, avoiding fluctuations in detection data caused by severe impacts. When the impact rod 2 completes its rebound action and reaches its axial movement limit, the inner bottom wall of the annular limiting groove 41 contacts the buffer pad 421 at the top of the limiting ring 42. The buffer pad 421 is made of elastic material (such as rubber or silicone), which converts the impact kinetic energy into elastic potential energy through its own deformation, reducing the impact force and achieving flexible buffering to avoid direct hard collisions between metal components.

[0028] To facilitate the rotation of the cap 43, several protruding rods 431 are circumferentially fixedly connected to the outer wall of the cap 43. The evenly distributed protruding rods 431 on the outer wall of the cap 43 provide a convenient force-applying structure for the operator, allowing for quick rotation of the cap 43 without the need for special tools, thus enabling the installation and removal of the limiting ring 42 and significantly improving the convenience of equipment maintenance and debugging. The operator holds the protruding rods 431 with their fingers or tools, applying a rotational torque. The protruding rods 431 transmit the torque to the cap 43, causing it to rotate along the threaded direction at the bottom of the housing 1. Because the protruding rods 431 are circumferentially distributed, uniform force application is ensured, preventing slippage and easily completing the tightening or loosening of the cap 43, achieving rapid installation and fixation of the limiting ring 42.

[0029] For the automatic rebound of the impact rod 2: the automatic rebound assembly 3 includes a fixed sleeve 31 that is slidably sleeved on the impact rod 2 and inserted into the bottom of the housing 1, a central guide rod 32 inserted into the top of the impact rod 2, an impact hammer 33 sleeved on the central guide rod 32, and an impact spring 34 sleeved on the central guide rod 32. The two ends of the impact spring 34 are respectively fixedly connected between the impact hammer 33 and the fixed sleeve 31. A guide baffle 35 is fixedly connected to the top of the central guide rod 32, and a snap-fit ​​element 36 is provided on the guide baffle 35 for engaging with the impact hammer 33. The automatic rebound assembly 3 realizes the automatic rebound function of the impact rod 2 by storing and releasing the elastic potential energy of the impact spring 34, in conjunction with the automatic release mechanism of the snap-fit ​​element 36, thereby improving the automation level of the detection process and the stability of the rebound energy, and avoiding detection errors caused by uneven manual operation force. When the impact rod 2 moves into the housing 1 due to the reaction force of the concrete surface, it drives the central guide rod 32 to move synchronously. The guide baffle 35 at the top of the central guide rod 32 is engaged with the T-shaped sleeve 363 of the impact hammer 33 through the snap-fit ​​36, thereby pulling the impact hammer 33 to stretch the impact spring 34 and store elastic potential energy. When the impact rod 2 moves to the preset position, the snap-fit ​​36 ​​is triggered to release, the impact spring 34 releases its potential energy, and drives the impact hammer 33 to quickly strike the impact rod 2, causing it to rebound and complete a detection action. The whole process does not require manual intervention.

[0030] The locking component 36 includes a through slot formed on the guide baffle 35, a U-shaped locking plate 361 hinged in the through slot, and a fastening spring 362 that abuts against the U-shaped locking plate 361 inside the through slot. A T-shaped sleeve 363 is fixedly connected to the top of the impact hammer 33, and the top of the T-shaped sleeve 363 engages with the bottom of the U-shaped locking plate 361. Through the engagement of the U-shaped locking plate 361 and the T-shaped sleeve 363, the locking component 36 ensures that the impact hammer 33 and the guide baffle 35 move synchronously during the charging process of the spring spring 34, and that the elastic force of the fastening spring 362 achieves stable engagement when the preset position is reached, preventing accidental disengagement during the charging process. Simultaneously, the precise triggering during disengagement ensures a stable output of rebound energy, improving the consistency and reliability of the test results. In the initial state, the fastening spring 362 pushes the U-shaped clamping plate 361 to rotate around the hinge axis, so that the bottom of the U-shaped clamping plate 361 engages with the T-shaped sleeve 363 on the top of the impact hammer 33, rigidly connecting the guide baffle 35 and the impact hammer 33; when the impact rod 2 drives the guide baffle 35 to move axially, the impact hammer 33 moves synchronously and stretches the impact spring 34 to store force; when the U-shaped clamping plate 361 contacts the external release structure (such as the tapered tube 39), the external force forces the U-shaped clamping plate 361 to overcome the elastic force of the fastening spring 362 and retract inward, disengaging from the T-shaped sleeve 363, releasing the impact hammer 33, and completing the rebound trigger.

[0031] The automatic rebound assembly 3 also includes a pressure spring 37 disposed on the top of the housing 1. The bottom of the pressure spring 37 abuts against the top of the guide baffle 35. A tail cap 38 is threadedly connected to the top of the housing 1. A tapered tube 39 adapted to the U-shaped clamp 361 is fixedly connected to the bottom of the tail cap 38. The larger diameter of the tapered tube 39 is arranged towards the guide baffle 35, and the smaller diameter is arranged towards the tail cap 38. The cooperation between the pressure spring 37 and the tapered tube 39 provides a stable triggering mechanism for the release of the U-shaped clamp 361, ensuring that the spring rod 2 accurately releases the potential energy of the spring tension spring 34 when it is pressed and moved to a specific position. This avoids rebound failure or energy instability caused by manual operation position deviation, and improves the reliability and intelligence of the automatic rebound device. When the impact rod 2 moves into the housing 1, the central guide rod 32 drives the guide baffle 35 to move upward and compress the pressure spring 37. At the same time, the U-shaped clamping plate 361 enters the tapered tube 39 area at the bottom of the tail cap 38 along with the guide baffle 35. The inner wall of the tapered tube 39 is tapered (the larger diameter faces the guide baffle 35). As the guide baffle 35 continues to move upward, the inner wall of the tapered tube 39 applies a radial contraction force to the top of the U-shaped clamping plate 361, forcing the U-shaped clamping plate 361 to rotate around the hinge axis and disengage the bottom from the T-shaped sleeve 363. At this time, the impact spring 34 releases potential energy, driving the impact hammer 33 to rebound and strike the impact rod 2, completing the detection action. The pressure spring 37 then assists the guide baffle 35 in resetting after rebounding.

[0032] It should be noted that many of the standard parts used in this application are available on the market, while non-standard parts can be specially customized. The connection method used in this application is also a very common method in the mechanical field, and will not be described in detail here.

[0033] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. An automatic rebound device for testing the concrete strength of highway tunnels, comprising a housing (1), a striking rod (2) inserted into one end of the housing (1), and an automatic rebound assembly (3) connected to the striking rod (2); Its features are: The housing (1) is provided with a limiting mechanism (4) for axial movement of the impact rod (2). The limiting mechanism (4) includes an annular limiting groove (41) opened on the outside of the impact rod (2), a limiting ring (42) that moves axially on the annular limiting groove (41), and a cap (43) sleeved on the impact rod (2) and the limiting ring (42) and threadedly connected to the bottom of the housing (1) for fixing the limiting ring (42) to the bottom of the housing (1).

2. The automatic rebound hammer device for testing the concrete strength of highway tunnels according to claim 1, characterized in that: A buffer pad (421) is fixedly connected to the top of the limiting ring (42).

3. The automatic rebound hammer device for testing the concrete strength of highway tunnels according to claim 1, characterized in that: Several protruding rods (431) are fixedly connected in a ring around the outer wall of the cap (43).

4. The automatic rebound hammer device for testing the concrete strength of highway tunnels according to claim 1, characterized in that: The automatic rebound assembly (3) includes a fixed sleeve (31) slidably sleeved on the impact rod (2) and inserted into the bottom of the housing (1), a central guide rod (32) inserted into the top of the impact rod (2), an impact hammer (33) sleeved on the central guide rod (32), and an impact spring (34) sleeved on the central guide rod (32). The two ends of the impact spring (34) are respectively fixedly connected between the impact hammer (33) and the fixed sleeve (31). A guide baffle (35) is fixedly connected to the top of the central guide rod (32), and a snap-fit ​​part (36) for snapping with the impact hammer (33) is provided on the guide baffle (35).

5. The automatic rebound hammer device for testing the concrete strength of highway tunnels according to claim 4, characterized in that: The snap-fit ​​component (36) includes a through groove formed on the guide baffle (35), a U-shaped snap-fit ​​plate (361) hinged in the through groove, a fastening spring (362) that abuts against the U-shaped snap-fit ​​plate (361) is provided inside the through groove, and a T-shaped sleeve (363) is fixedly connected to the top of the impact hammer (33), and the top of the T-shaped sleeve (363) engages with the bottom of the U-shaped snap-fit ​​plate (361).

6. The automatic rebound hammer device for testing the concrete strength of highway tunnels according to claim 5, characterized in that: The automatic rebound assembly (3) also includes a pressure spring (37) disposed on the top of the housing (1). The bottom of the pressure spring (37) abuts against the top of the guide baffle (35). The top of the housing (1) is threadedly connected to a tail cap (38). The bottom of the tail cap (38) is fixedly connected to a tapered tube (39) adapted to the U-shaped clamp (361). The major diameter of the tapered tube (39) is arranged towards the guide baffle (35), and the minor diameter is arranged towards the tail cap (38).

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