Beckman beam test roadbed and pavement rebound deflection test device

Abstract

The utility model provides a Beckman beam test roadbed pavement rebound deflection test device which comprises a Beckman beam body and an adjusting seat used for fixing a dial indicator, the dial indicator is connected with a horizontal graduated scale, and the dial indicator is slidably connected with an indicating head matched with the horizontal graduated scale; the dial indicator is rotatably connected with a spline shaft, the spline shaft is fixedly sleeved with a large pointer, the spline shaft is slidably sleeved with a fifth gear, and the fifth gear can drive the indicating head to move along the horizontal graduated scale. The device is convenient to operate and reasonable in structure, can timely record the maximum value of the dial indicator without manual recording when a roadbed pavement rebound deflection test is carried out, effectively reduces the labor intensity, can timely and accurately record test data, and effectively improves the test accuracy and efficiency.

Description

Technical Field

[0001] This utility model relates to the field of road testing technology, specifically to a Beckman beam test device for roadbed and pavement rebound deflection. Background Technology

[0002] In road construction, the quality of the subgrade and pavement directly affects the road's service life and driving safety. The subgrade is the foundation of the road, bearing the traffic load transmitted from the pavement, while the pavement is in direct contact with vehicle tires. Rebound deflection is a key indicator for measuring the overall strength and stiffness of the subgrade and pavement. The basic principle of the Benkelman beam is based on the theory of elastic half-space. When vehicle loads are applied to the pavement, the pavement undergoes vertical deformation; measuring this deformation reflects the pavement's deflection.

[0003] Patent CN 219059676 U discloses a Beckman beam deflectometer for precise alignment, comprising a base on which a Beckman beam is mounted. A test head is positioned on the lower side of one end of the Beckman beam, and a test screw is positioned on the upper side of the other end. A dial indicator frame is arranged beside the other end of the Beckman beam, and a support plate is provided on the side of the frame. A dial indicator is mounted on the support plate, and the contact of the dial indicator abuts against the center of the upper nut of the test screw. The test screw is detachably fixed to the dial indicator frame. However, it still has the following problems: when using the dial indicator, the maximum value on the dial needs to be read immediately, but the maximum value is an instantaneous value. Currently, conventional dial indicators rely on human visual recording, making accurate reading difficult. Utility Model Content

[0004] To address the problems existing in the prior art, a Beckman beam testing device for roadbed and pavement rebound deflection is provided. This device is easy to operate and has a reasonable structure. During roadbed and pavement rebound deflection tests, it can promptly record the maximum values ​​observed by the dial gauge, eliminating the need for manual recording and effectively reducing labor intensity. Furthermore, it can record test data accurately and promptly, significantly improving the accuracy and efficiency of the test.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] This invention proposes a Beckman beam test device for roadbed and pavement rebound deflection, comprising a Beckman beam body and an adjustment seat for fixing a dial indicator. The dial indicator is connected to a horizontal scale, and the dial indicator is slidably connected to an indicator head that cooperates with the horizontal scale. The dial indicator is rotatably connected to a spline shaft, and a large pointer is fixedly mounted on the spline shaft. A fifth gear is slidably mounted on the spline shaft, and the fifth gear can drive the indicator head to move along the horizontal scale.

[0007] Preferably, the splined shaft is fixedly sleeved with a fourth gear, and the dial indicator is rotatably connected to a first gear. The first gear and the fourth gear mesh with each other, and the diameter of the first gear is larger than the diameter of the fourth gear.

[0008] Preferably, the first gear is coaxially fixedly connected to the second gear, the dial indicator is slidably connected to the probe, the probe is fixedly connected to the first rack, the first rack and the second gear mesh, and the diameter of the first gear is larger than the diameter of the second gear.

[0009] Preferably, the probe is fitted with a spring for probe reset, one end of the spring is connected to the dial indicator, and the other end of the spring is connected to the probe.

[0010] Preferably, the dial indicator is rotatably connected to a small pointer, and the small pointer is coaxially fixedly connected to a third gear. The third gear meshes with the fourth gear, and the diameter of the third gear is larger than the diameter of the fourth gear.

[0011] Preferably, it also includes a coil spring for resetting the small pointer, one end of which is connected to the small pointer and the other end of which is connected to the dial indicator.

[0012] Preferably, the dial indicator is fixedly connected to a fixed base, and the fixed base is slidably connected to a second rack, which is located on one side of the indicator head, and the second rack meshes with the fifth gear.

[0013] Preferably, the dial indicator is slidably connected to a sliding sleeve, the sliding sleeve is rotatably connected to the fifth gear, and the dial indicator is threadedly connected to an adjusting rod, the adjusting rod being rotatably connected to the sliding sleeve.

[0014] Preferably, the horizontal scale and the dial indicator are slidably connected, the dial indicator is threaded with a screw, and the screw and the horizontal scale are rotatably connected.

[0015] Preferably, the indicator head is connected to two ends with compression springs, which can slide along the surface of the dial indicator.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. This utility model is equipped with an indicator head. When the large pointer rotates, it can drive the second rack to move horizontally. The second rack can push the indicator head to move. The indicator head moves along the horizontal scale to record the maximum value. It is easy to operate and has a reasonable structure. When conducting roadbed and pavement rebound deflection tests, it can record the maximum value of the dial gauge in a timely manner without manual recording, effectively reducing labor intensity. It can also record test data in a timely and accurate manner, effectively improving the accuracy and efficiency of the test.

[0018] 2. This utility model is equipped with a splined shaft. When the dial indicator is engaged with the Beckman beam, rotating the adjusting rod moves the fifth gear to one side of the second rack. At this time, when the large pointer rotates, it will not drive the second rack to move. Only after the dial indicator has been calibrated and a roadbed and pavement rebound deflection test is performed, rotating the adjusting rod will engage the fifth gear and the second rack, at which point the maximum value will be recorded. This eliminates the need for repeated adjustment of the indicator head, improving the ease of use of the device and effectively increasing its efficiency.

[0019] 3. This utility model is equipped with a screw. When the screw rotates, it can drive the horizontal scale to move, so that the zero mark of the horizontal scale can always be in a state of engagement with the indicator head. This makes it convenient to record the maximum value when the indicator head moves. It is very convenient for staff to record the maximum value and is easy to operate. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 This is a perspective view of the utility model;

[0022] Figure 2 This is a front view of the dial indicator structure in this utility model;

[0023] Figure 3 This is a cross-sectional view (front view) of the dial indicator structure in this utility model.

[0024] Figure 4 This is a side view of the dial indicator structure in this utility model;

[0025] Figure 5 This is a cross-sectional view (rear view) of the dial indicator structure in this utility model.

[0026] Figure 6 This is a rear view of the dial indicator structure in this utility model;

[0027] Figure 7 This is a schematic diagram of the indicator head part in this utility model.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Bracket; 2. Adjustment seat; 3. Dial indicator; 4. Beckman beam; 5. Stylus; 6. First gear; 7. Second gear; 8. First rack; 9. Large pointer; 10. Small pointer; 11. Third gear; 12. Coil spring; 13. Fixed seat; 14. Fourth gear; 15. Fifth gear; 16. Sliding sleeve; 17. Second rack; 18. Adjustment rod; 19. Splined shaft; 20. Spring; 21. Indicator head; 22. Horizontal scale; 23. Screw; 24. Compression spring. Detailed Implementation

[0030] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Example 1

[0031] like Figures 1-7 As shown in the figure, this embodiment proposes a Beckman beam test device for roadbed and pavement rebound deflection, including a Beckman beam body 4 and an adjusting seat 2 for fixing a dial gauge 3, and also includes a bracket 1. The bracket 1 and the adjusting seat 2 are slidably connected, and the adjusting seat 2 is threadedly connected to an adjusting screw. The adjusting screw can abut against the bracket 1 to lock the adjusting seat 2 relative to the bracket 1. The height of the dial gauge 3 can be adjusted by the adjusting screw.

[0032] The adjusting seat 2 has a placement hole, in which the dial indicator 3 can be placed. The adjusting seat 2 is threaded with a locking bolt. After the locking bolt passes through the placement hole, it can abut against the dial indicator 3, thereby fixing the dial indicator 3 to the adjusting seat 2, which facilitates subsequent measurement work.

[0033] It also includes a support leg, which is rotatably connected to the Beckman beam 4. The support leg is located at one-third of the length of the Beckman beam 4, such that the length of the Beckman beam 4 on one side of the support leg is twice the length of the Beckman beam 4 on the other side, while the dial indicator 3 is located on the side of the shorter Beckman beam 4.

[0034] The dial indicator 3 includes a large dial and a small dial. A horizontal scale 22 is connected to the other side of the dial indicator 3. The large dial and the small dial are located on the same side of the dial indicator 3, and both the large dial and the small dial are set with corresponding scales. The horizontal scale 22 is set on the other side of the dial indicator 3. The horizontal scale 22 is used to record the maximum value that occurs during the measurement process.

[0035] The dial indicator 3 is slidably connected to an indicator head 21 that mates with the horizontal scale 22. The dial indicator 3 is rotatably connected to a splined shaft 19, on which a large pointer 9 is fixedly mounted. A fifth gear 15 is slidably mounted on the splined shaft 19, and the fifth gear 15 can drive the indicator head 21 to move along the horizontal scale 22. The indicator head 21 can only move along the length of the horizontal scale 22. By observing the position of the indicator head 21 on the horizontal scale 22, the maximum value observed during the measurement is recorded.

[0036] The spline shaft 19 is fixedly fitted with the fourth gear 14. The dial indicator 3 is rotatably connected to the first gear 6. The first gear 6 and the fourth gear 14 mesh with each other. The diameter of the first gear 6 is larger than the diameter of the fourth gear 14. When the first gear 6 rotates, it drives the fourth gear 14 to rotate, which in turn drives the spline shaft 19 to rotate. The spline shaft 19 drives the large pointer 9 to rotate. The large pointer 9 cooperates with the large dial, and at this time, corresponding recording work can be performed.

[0037] The first gear 6 is coaxially fixedly connected to the second gear 7, and the dial indicator 3 is slidably connected to the probe 5. The probe 5 can only slide in the vertical direction. The probe 5 is fixedly connected to the first rack 8, and the first rack 8 and the second gear 7 mesh with each other. The diameter of the first gear 6 is larger than the diameter of the second gear 7. The probe 5 can drive the first rack 8 to rotate, the first rack 8 drives the second gear 7 to rotate, and the second gear 7 drives the first gear 6 to rotate.

[0038] The probe 5 is equipped with a spring 20 for resetting the probe 5. One end of the spring 20 is connected to the dial indicator 3, and the other end of the spring 20 is connected to the probe 5. Under the elastic force of the spring 20, the large pointer 9 can indicate the 0 mark at this time.

[0039] The dial indicator 3 is rotatably connected to a small pointer 10, which works with the small dial. The small pointer 10 is coaxially fixedly connected to a third gear 11, which meshes with a fourth gear 14. The diameter of the third gear 11 is larger than that of the fourth gear 14. When the fourth gear 14 rotates, it can drive the third gear 11 to rotate, and the third gear 11 drives the small pointer 10 to rotate.

[0040] It also includes a coil spring 12 for resetting the small pointer 10. One end of the coil spring 12 is connected to the small pointer 10, and the other end of the coil spring 12 is connected to the dial indicator 3. Under the action of the spring force of the coil spring 12, the small pointer 10 can indicate the 0 mark at this time.

[0041] The minute linear movement of the probe 5 caused by the measured dimension is amplified by gear transmission and transformed into the rotation of the pointer on the dial, thereby reading the size of the measured dimension. The reading accuracy of the dial indicator 3 is 0.01 mm. One rotation of the large pointer 9 is 1 mm, and at this time the small pointer 10 rotates exactly one rotation, indicating the integer millimeter.

[0042] The dial indicator 3 is fixedly connected to a fixed base 13, and the fixed base 13 is slidably connected to a second rack 17. The second rack 17 is located on one side of the indicator head 21. The second rack 17 meshes with the fifth gear 15, and the fifth gear 15 can slide along the surface of the spline shaft 18.

[0043] When the fifth gear 15 moves to mesh with the second rack 17, the rotation of the fifth gear 15 can drive the second rack 17 to move, and in turn drive the indicator head 21 to move. When the fifth gear 15 is located on one side of the second rack 17, it cannot drive the second rack 17 to move. The second rack 17 and the indicator head 21 are in contact. One side of the indicator head 21 is located outside the dial indicator 3, which makes it easy to manually reset the indicator head 21.

[0044] When the large pointer 9 rotates, it drives the second rack 17 to move horizontally, and the second rack 17 pushes the indicator head 21 to move. The indicator head 21 moves along the horizontal scale 22 to record the maximum value. It is easy to operate and has a reasonable structure. When conducting roadbed and pavement rebound deflection tests, it can record the maximum value of the dial gauge 3 in a timely manner without manual recording, which effectively reduces labor intensity. It can also record test data in a timely and accurate manner, which effectively improves the accuracy and efficiency of the test.

[0045] The dial indicator 3 is slidably connected to a sliding sleeve 16, which is rotatably connected to the fifth gear 15. The dial indicator 3 is threadedly connected to an adjusting rod 18, which is rotatably connected to the sliding sleeve 16. By rotating the adjusting rod 18, the adjusting rod 18 can drive the sliding sleeve 16 to move, and the sliding sleeve 16 drives the fifth gear 15 to move.

[0046] When dial indicator 3 is used in conjunction with the Beckman beam 4, the adjustment rod 18 is rotated, which moves the fifth gear 15 to one side of the second rack 17. At this time, when the large pointer 9 rotates, it will not drive the second rack 17 to move. Only after dial indicator 3 has been calibrated and the roadbed and pavement rebound deflection test is performed, the adjustment rod 18 is rotated to mesh the fifth gear 15 and the second rack 17. Only then will the maximum value be recorded. There is no need to repeatedly adjust the indicator head 21, which improves the convenience of the device and effectively improves the efficiency of use.

[0047] In addition, to facilitate the engagement of the fifth gear 15 and the second rack 17, the ends of the fifth gear 15 and the second rack 17 that are close to each other are both inclined surfaces, which better facilitates the meshing of the fifth gear 15 and the second rack 17.

[0048] The horizontal scale 22 and the dial indicator 3 are slidably connected. The dial indicator 3 is threadedly connected to a screw 23, which is rotatably connected to the horizontal scale 22. Through the screw 23, its rotation drives the horizontal scale 22 to move, ensuring that the zero mark of the horizontal scale 22 is always aligned with the indicator head 21. This facilitates the recording of maximum values ​​as the indicator head 21 moves, making it very convenient for operators to record maximum values ​​and providing easy operation. Example 2

[0049] Reference Appendix Figure 7 The other structures are the same as in Embodiment 1, except that the movement of the indicator head is taken into account in this embodiment.

[0050] The indicator head 21 is connected to two ends of a compression spring 24, which can slide along the surface of the dial indicator 3. The indicator head 21 is also fixedly connected to a telescopic rod, and the other end of the telescopic rod is connected to a slide plate. The compression spring 24 is sleeved on the telescopic rod, with one end of the compression spring 24 connected to the indicator head 21 and the other end of the compression spring 24 connected to the slide plate.

[0051] Under the elastic force of the compression spring 24, the slide plate is always in sliding contact with the dial indicator 3, thereby increasing the friction between the indicator head 21 and the dial indicator 3, which facilitates the fixing of the indicator head 21 after it moves. The extension rod can keep the compression spring 24 in a linear state, prevent the compression spring 24 from bending, and better support the slide plate.

[0052] Specific working process: When conducting tests on asphalt pavements, the deflection of the asphalt pavement is based on an average asphalt surface temperature of 20℃. No correction is needed if the average pavement temperature is within 20℃ ± 2℃. For asphalt pavements with a thickness greater than 5cm, the deflection value should be corrected for temperature. The Beckman beam deflector 4 comes in two specifications: one is 3.6m long with front and rear arms of 2.4m and 1.2m respectively; the other is an extended deflector 5.4m long with front and rear arms of 3.6m and 1.8m respectively. When measuring on semi-rigid base asphalt pavements or cement concrete pavements, the 5.4m long Beckman beam deflector should be used. For flexible base or mixed-structure asphalt pavements, the 3.6m long Beckman beam deflector can be used.

[0053] After setting up the measuring points on the asphalt pavement, align the wheel gap of the test vehicle with the measuring points about 3-5 cm behind them. Insert the Beckman beam 4 into the gap between the rear wheels of the test vehicle, aligning it with the direction of the test vehicle. At the same time, the Beckman beam 4 must not touch the tires. At this point, the side of the Beckman beam 4 should be located on the measuring point, about 3-5 cm in front of the center of the wheel gap. Then, place the dial indicator 3 on the adjustment seat 2 and gently tap the Beckman beam 4 with your finger to check whether the dial indicator 3 can stably return to zero. One or two Beckman beams 4 can be set.

[0054] After adjusting the position of dial indicator 3, rotate the adjusting rod 18. The adjusting rod 18 drives the fifth gear 15 to move through the sliding sleeve 16, so that the fifth gear 15 meshes with the second rack 17. At the same time, the relative position of the horizontal scale 22 and the indicator head 21 is adjusted by the screw 23.

[0055] As the test vehicle moves, the rebound of the asphalt pavement drives the probe 5 through the Beckman beam 4. The probe 5 drives the first gear 6 and the second gear 7 to rotate. The second gear 7 drives the spline shaft 19 to rotate through the fourth gear 14. The spline shaft 19 drives the large pointer 9 to rotate. At the same time, the spline shaft 19 drives the fifth gear 15 to rotate. The fifth gear 15 drives the second rack 17 to move. The second rack 17 drives the indicator head 21 to move.

[0056] After the test vehicle has been traveling for a period of time, the probe 5 is reset. The probe 5 drives the spline shaft 19 to reverse, and the spline shaft 19 drives the large pointer 9 to rotate in the opposite direction. At this time, when the second rack 17 moves, it will not drive the indicator head 21 to move. The value indicated by the indicator head 21 at this time is the maximum value that occurred during the test.

[0057] The maximum value was recorded as L1. After the test vehicle moved more than 3 meters out of the test area, and the large pointer 9 of the dial indicator 3 stabilized, the final deflection value L2 was read. During the above test, the forward speed of the test vehicle was about 5 km / h. The final rebound deflection value of the measuring point was obtained as L. T = (L1-L2)×2, where the units for the above degrees are all 0.01mm. The rebound deflection value of asphalt pavement with an asphalt surface layer thickness greater than 5cm should be corrected for temperature.

[0058] In addition, during the test, no part of the Beckman beam 4 should come into contact with the tire, and the road surface temperature at each measuring point should be recorded at all times. The measuring point of the Beckman beam 4 is located 3cm to 5cm in front of the center of the rear wheel clearance. When using a deflectometer with a length of 5.4m for measurement, no correction for the deformation of the support point is required.

[0059] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A Beckman beam test apparatus for roadbed and pavement rebound deflection, comprising a Beckman beam (4) and an adjustment seat (2) for fixing a dial gauge (3), characterized in that, The dial indicator (3) is connected to a horizontal scale (22), and the dial indicator (3) is slidably connected to an indicator head (21) that cooperates with the horizontal scale (22); the dial indicator (3) is rotatably connected to a spline shaft (19), the spline shaft (19) is fixedly fitted with a large pointer (9), the spline shaft (19) is slidably fitted with a fifth gear (15), and the fifth gear (15) can drive the indicator head (21) to move along the horizontal scale (22).

2. A device for testing the roadbed and pavement resilience deflection according to claim 1, characterized in that, The spline shaft (19) is fixedly fitted with a fourth gear (14), and the dial indicator (3) is rotatably connected to a first gear (6). The first gear (6) and the fourth gear (14) mesh with each other, and the diameter of the first gear (6) is greater than the diameter of the fourth gear (14).

3. A device for testing the roadbed and pavement resilience deflection according to claim 2, characterized in that, The first gear (6) is coaxially fixedly connected to the second gear (7), the dial indicator (3) is slidably connected to the probe (5), the probe (5) is fixedly connected to the first rack (8), the first rack (8) and the second gear (7) mesh with each other, and the diameter of the first gear (6) is larger than the diameter of the second gear (7).

4. A device for testing the roadbed and pavement resilience deflection according to claim 3, characterized in that, The probe (5) is fitted with a spring (20) for resetting the probe (5). One end of the spring (20) is connected to the dial indicator (3), and the other end of the spring (20) is connected to the probe (5).

5. A device for testing the roadbed and pavement resilience deflection according to claim 2, characterized in that, The dial indicator (3) is rotatably connected to a small pointer (10), and the small pointer (10) is coaxially fixedly connected to a third gear (11). The third gear (11) and the fourth gear (14) mesh with each other, and the diameter of the third gear (11) is larger than the diameter of the fourth gear (14).

6. The Beckman beam test device for roadbed and pavement rebound deflection according to claim 5, characterized in that, It also includes a coil spring (12) for resetting the small pointer (10), one end of which is connected to the small pointer (10) and the other end of which is connected to the dial indicator (3).

7. A device for testing the roadbed and pavement resilience deflection according to claim 1, characterized in that, The dial indicator (3) is fixedly connected to a fixed base (13), and the fixed base (13) is slidably connected to a second rack (17). The second rack (17) is located on one side of the indicator head (21), and the second rack (17) meshes with the fifth gear (15).

8. A device for testing the roadbed pavement resilience deflection of a beam according to claim 7, characterized in that, The dial indicator (3) is slidably connected to a sliding sleeve (16), the sliding sleeve (16) and the fifth gear (15) are rotatably connected, and the dial indicator (3) is threadedly connected to an adjusting rod (18), the adjusting rod (18) and the sliding sleeve (16) are rotatably connected.

9. The device for testing the roadbed and pavement deflection according to claim 1, wherein, The horizontal scale (22) and the dial indicator (3) are slidably connected. The dial indicator (3) is threadedly connected to a screw (23). The screw (23) and the horizontal scale (22) are rotatably connected.

10. The device for testing the roadbed and pavement deflection according to claim 1, wherein, The indicator head (21) is connected to two ends with compression springs (24), which can slide along the surface of the dial indicator (3).

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