A falling weight deflectometer output displacement detection device

Abstract

This utility model discloses a displacement detection device for a falling weight deflectometer, comprising a fixed frame and a pad. The bottom of the pad has a movable groove for accommodating the fixed frame, and the top has a through hole communicating with the movable groove. The fixed frame has a connecting block at the top and a top block at the bottom. A spring is provided between the fixed frame and the movable groove. An acceleration sensor is provided on the fixed frame. This utility model's displacement detection device for a falling weight deflectometer facilitates the testing of the displacement sensor's accuracy.

Description

Technical Field

[0001] This utility model relates to the field of displacement detection equipment, and in particular to a displacement detection device for a falling weight deflectometer. Background Technology

[0002] The falling weight deflectometer is used to simulate traffic loads. Under computer control, a weight of a certain mass is lifted to a certain height by a hydraulic transmission device and then dropped freely. The impact force acts on a bearing plate and is transmitted to the road surface, thus applying a pulse load to the road surface, causing instantaneous deformation of the road surface. Displacement sensors distributed at different distances from the measuring points detect the deformation of the structural layer surface. The recording system transmits the signals to the computer, thus measuring the dynamic deflection and deflection basin generated under dynamic load. The test data can be used to calculate the modulus of the pavement structural layer, thereby scientifically evaluating the bearing capacity of the pavement. However, multiple displacement sensors may have varying degrees of error, leading to inaccurate test data, and there is a lack of convenient devices for testing the accuracy of displacement sensors. Utility Model Content

[0003] To address the aforementioned issues, this invention provides a displacement detection device for a falling weight deflectometer, facilitating the detection of displacement sensor accuracy.

[0004] The technical solution of this utility model is as follows:

[0005] A displacement detection device for a falling weight deflectometer includes a fixed frame and a pad. The bottom of the pad has a movable groove for accommodating the fixed frame, and the top has a through hole communicating with the movable groove. The top of the fixed frame has a connecting block, and the bottom has a top block. The connecting block passes through the through hole. A spring is provided between the fixed frame and the movable groove. An acceleration sensor is provided on the fixed frame.

[0006] In a further technical solution, the fixing frame is a rectangular frame with a side opening.

[0007] In a further technical solution, the top center of the fixing frame is provided with a threaded hole, the bottom of the connecting block is provided with a connecting post that matches the threaded hole, the connecting post is threadedly connected to the fixing frame and passes through the threaded hole, and the acceleration sensor is threadedly connected to the end of the connecting post.

[0008] In a further technical solution, a wire-passing hole with a connecting movable groove is provided on one side of the pad.

[0009] In a further technical solution, a connecting groove is provided on the bottom edge of the movable groove, a mounting post is provided in the connecting groove, a first hanging hole is provided radially through the mounting post, a connecting edge is provided on the bottom edge of the fixed frame, a second hanging hole is provided on the connecting edge, and the two ends of the spring are respectively connected to the first hanging hole and the second hanging hole.

[0010] In a further technical solution, a groove is provided in the middle of the top of the pad for placing a soft pad, and the through hole is located in the middle of the groove.

[0011] The beneficial effects of this utility model are:

[0012] 1. This device can be installed on the ground at the bottom of the displacement sensor of an existing falling weight deflectometer, so that the end of the displacement sensor can abut against the top of the connecting block. When the falling weight is tested, the top block of the fixed frame can contact the ground. The vibration of the top block can be transmitted to the connecting block through the fixed frame, and finally to the displacement sensor. The accuracy of the displacement sensor can be calibrated by comparing the detection value of the displacement sensor with the value calculated by the acceleration sensor during this process.

[0013] 2. The square frame bracket facilitates the installation of the accelerometer, with the cable routed from one side to the cable hole;

[0014] 3. A soft pad can be placed in the groove to prevent the connecting block from shifting or wobbling when passing through the through hole. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of the output displacement detection device of the falling weight deflectometer according to an embodiment of this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of the pad block described in an embodiment of this utility model;

[0017] Figure 3 This is a cross-sectional schematic diagram of the pad block described in an embodiment of this utility model;

[0018] Figure 4 This is a structural schematic diagram of the fixing frame described in an embodiment of the present utility model.

[0019] Explanation of reference numerals in the attached figures:

[0020] 10. Fixing bracket; 11. Connecting block; 12. Top block; 13. Connecting column; 14. Connecting edge; 15. Second hanging hole; 20. Pad block; 21. Movable groove; 22. Through hole; 23. Connecting groove; 24. Mounting column; 25. First hanging hole; 26. Wire passage hole; 27. Pad groove; 30. Spring. Detailed Implementation

[0021] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0022] Example:

[0023] like Figures 1-4As shown, a falling weight deflectometer output displacement detection device includes a fixed frame 10 and a pad 20. The pad 20 has a circular cross-section, with a movable groove 21 at the bottom center to accommodate the fixed frame 10, and a through hole 22 at the top communicating with the movable groove 21. The fixed frame 10 is a side-opening rectangular frame, with a connecting block 11 at the top, which passes through the through hole, and a top block 12 at the bottom. The bottom end of the top block 12 can be shaped like a ball head, aligned with the bottom surface of the pad 20. A threaded hole can be formed at the top center of the fixed frame 10, and a connecting post 13 matching the threaded hole can be provided at the bottom of the connecting block 11. 3 is threaded to the fixed bracket 10 and passes through the threaded hole. The acceleration sensor (not shown in the figure) can be threaded to the end of the connecting post 13. The bottom edge of the movable groove 21 is provided with an annular connecting groove 23. Four mounting posts 24 are symmetrically and vertically arranged on both sides of the connecting groove 23. The mounting posts 24 are radially provided with a first hanging hole 25. The bottom sides of the fixed bracket 10 are provided with connecting edges 14. Each of the two connecting edges 14 is provided with two second hanging holes 15 that are respectively aligned with the mounting posts 24. The two ends of the spring 30 are respectively connected to the first hanging hole 25 and the second hanging hole 15 for connecting the fixed bracket 10 to the movable groove 21.

[0024] The working principle of the above technical solution is as follows:

[0025] During testing, springs 30 are used to connect the four first and second hanging holes to install the fixing frame 10 onto the pad 20. Then, the pad 20 is installed on the ground at the bottom of the displacement sensor of the falling weight deflectometer. At this time, the top block of the fixing frame is tightly attached to the ground due to the elastic force of the four springs, so that the end of the displacement sensor can abut against the top of the connecting block 11. During the falling weight test, the acceleration sensor on the fixing frame 10 collects the ground displacement data and transmits the motion state through the fixing frame 10 to the connecting block 11, and finally to the displacement sensor of the falling weight deflectometer. The accuracy of the displacement sensor of the falling weight deflectometer is calibrated by comparing the displacement data of the displacement sensor with the displacement data collected by the acceleration sensor during this process.

[0026] In another embodiment, such as Figure 1-2 As shown, a wire-passing hole 26 communicating with the movable groove 21 is provided on one side of the pad 20, and the opening of the fixing bracket 10 is set facing the wire-passing hole 26.

[0027] The accelerometer sensor cable can be routed through the cable guide hole 26.

[0028] In another embodiment, such as Figure 1-2 As shown, a groove 27 is provided in the middle of the top of the pad 20 for placing a soft pad. The soft pad can be fixed in the groove 27 by bolts or rivets. A through hole 22 is provided in the middle of the groove 27.

[0029] The diameter of the through hole 22 is generally larger than the size of the part of the connecting block 11 that passes through the through hole 22. The opening in the middle of the soft pad placed in the pad groove 27 can fit the connecting block 11 perfectly, connecting and limiting the connecting block 11, which can prevent the connecting block 11 from swaying to the side.

[0030] The embodiments described above merely illustrate specific implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A displacement detection device for a falling weight deflectometer, characterized in that, The device includes a fixed frame and a pad. The bottom of the pad has a movable groove for accommodating the fixed frame, and the top has a through hole communicating with the movable groove. The fixed frame has a connecting block at the top and a top block at the bottom, and the connecting block passes through the through hole. A spring is provided between the fixed frame and the movable groove. An acceleration sensor is provided on the fixed frame.

2. The falling weight deflectometer output displacement detection device according to claim 1, characterized in that, The mounting bracket is a rectangular frame with side openings.

3. The displacement detection device for a falling weight deflectometer according to claim 1, characterized in that, The top center of the fixing frame is provided with a threaded hole, and the bottom of the connecting block is provided with a connecting post that matches the threaded hole. The connecting post is threadedly connected to the fixing frame and passes through the threaded hole. The acceleration sensor is threadedly connected to the end of the connecting post.

4. The displacement detection device for a falling weight deflectometer according to claim 2, characterized in that, One side of the pad has a wire-passing hole that connects to the movable groove.

5. The falling weight deflectometer output displacement detection device according to claim 2, characterized in that, The bottom edge of the movable groove is provided with a connecting groove, and a mounting post is provided in the connecting groove. The mounting post is radially provided with a first hanging hole. The bottom edge of the fixed frame is provided with a connecting edge, and a second hanging hole is provided on the connecting edge. The two ends of the spring are respectively connected to the first hanging hole and the second hanging hole.

6. The falling weight deflectometer output displacement detection device according to claim 1, characterized in that, The top center of the pad has a groove for placing a soft pad, and the through hole is located in the middle of the groove.

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