A dynamic cable tension testing instrument

Abstract

The present invention discloses a dynamic cable tension testing instrument, specifically related to the technical field of bridge engineering monitoring. The dynamic cable tension testing instrument includes: a mounting base, a mounting frame is fixed to the bottom of the mounting base, two supporting wheels are rotatably installed on one side of the mounting frame, the two supporting wheels are at the same horizontal level, a pressing wheel assembly is arranged on one side of the mounting frame, the pressing wheel assembly and the two supporting wheels cooperate to press the traction cable to bend, the pressing wheel assembly includes a frame, a pressing wheel is rotatably installed inside the frame, during detection, the traction cable is located between the two supporting wheels and the pressing wheel, and a triangular frame is arranged below the frame. The dynamic cable tension testing instrument provided by the present invention can collect the data of the pressure sensor during the movement of the traction cable, can monitor the tension change of the traction cable in real time, and provides real-time data support for construction.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering monitoring, and particularly to a dynamic cable tension testing instrument. Background Art

[0002] In recent years, due to its large spanning capacity and beautiful shape, suspension bridges are often used as key links to connect geographical obstacles and play an irreplaceable important role in China's infrastructure construction.

[0003] As the main load-bearing structure of a suspension bridge, the strength and stability of the main cable directly determine the reliability and durability of the bridge, and play a decisive role in ensuring the stability of the bridge under the influence of external factors such as wind load and temperature change. The erection of the main cable strands of a suspension bridge is one of the most critical and technically demanding processes in the construction of a suspension bridge. It is necessary to install a winch and a temporary towing cable to tow the numbered cable strands from the anchor to the top of the bridge tower. When the cable strands reach the top of the bridge tower, they are positioned and fixed according to the design position. However, during the hoisting process, the towing cable faces various hazards: First, the risk of overload. The towing cable needs to bear huge tension. Once it exceeds the bearing limit of the material, it may lead to structural instability. Second, the risk of vibration and fatigue. The continuous stress cycle caused by factors such as wind load and mechanical vibration may cause fatigue damage to the towing cable, accumulating into a fracture hazard. Finally, the risk of wear. The towing cable is prone to wear due to its repeated use and passing through components such as bridge towers, shortening its service life. The above damages will seriously affect the bearing capacity of the towing cable, resulting in inaccurate erection of the main cable, endangering the structural safety and stability after the bridge is completed. In addition, the fracture or serious damage of the towing cable will not only cause the interruption of the construction process, delay the construction period, increase the construction cost, but also trigger safety accidents, seriously threatening the safety of the operators. Therefore, during the process of hoisting the main cable with the towing cable, it is necessary to strictly monitor and maintain the towing cable to ensure its stability and reliability. By real-time monitoring the stress condition of the towing cable, potential risks such as overload and unbalanced tension can be discovered and prevented in time, ensuring the safe erection of the main cable during the construction process. In addition, accurate stress data helps to optimize the construction plan, improve the construction quality, ensure the safety of the operators, and provide a reliable guarantee for the long-term stable operation of the bridge. Therefore, the monitoring of the stress of the towing cable during the construction process of a suspension bridge is not only a technical requirement, but also a necessary measure for construction safety and quality management.

[0004] At present, the cable force measuring instruments used in bridge engineering can only measure the static cable force. Once the cable moves, it cannot meet the requirements, and its use in actual projects is very limited. It can only realize the measurement of the prestress of steel bars. During the erection process of the main cable of a suspension bridge, the towing cable is dynamic, and traditional tension meters cannot achieve measurement, let alone real-time measurement.

[0005] Therefore, it is necessary to provide a dynamic cable tension testing instrument to solve the above technical problems. Summary of the Invention

[0006] In view of the above situation, to overcome the defects of the prior art, the present invention provides a dynamic cable tension testing instrument that can collect data of pressure sensors during the movement of the towing cable, can monitor the tension change of the towing cable in real time, and provides real-time data support for construction.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A dynamic cable tension testing instrument, comprising: a mounting base, an installation frame is fixed to the bottom of the mounting base, two idler wheels are rotatably installed on one side of the installation frame, the two idler wheels are at the same horizontal level, a pressure wheel assembly is arranged on one side of the installation frame, the pressure wheel assembly cooperates with the two idler wheels to press the towing cable to bend, the pressure wheel assembly includes a frame, a pressure wheel is rotatably installed inside the frame, during detection, the towing cable is located between the two idler wheels and the pressure wheel, a triangular frame is arranged below the frame, a pressure sensor is fixed to the top of the triangular frame, the pressure sensor is fixed to the frame, a laser rangefinder is further arranged below the frame, the laser rangefinder is used to measure the moving distance of the frame, in the initial state, the moving distance of the frame measured by the laser rangefinder is, in this case, the towing cable is in contact with the two idler wheels and the pressure wheel, and the towing cable is in a horizontal state, when measuring the tension of the towing cable (as shown in the figure), the frame moves and drives the pressure wheel to move, pressing the towing cable to bend, the bending angle is θ, the moving distance of the frame can be measured by the laser rangefinder, which can be defined as L, when the towing cable towes the stay cable of the bridge, its tension is defined as T, and the length of the towing cable between the two idler wheels is defined as H.

[0009] Preferably, a fixing plate is fixedly installed on one side of the installation frame, a first screw rod penetrates through the fixing plate, the first screw rod is threadedly connected to the fixing plate, and one end of the first screw rod is rotatably connected to the triangular frame.

[0010] Preferably, two nuts are installed on the first screw rod, and the two nuts are respectively located above and below the fixing plate.

[0011] Preferably, a T-shaped block is fixed to one side of the frame close to the installation frame, and a T-shaped groove is formed on one side of the installation frame, and the T-shaped block can be installed in the T-shaped groove.

[0012] Preferably, limiting components are installed at both ends of the mounting base. The limiting components include a fixed pulley group and a movable pulley group. The fixed pulley group is fixed to the bottom of the mounting base, and the movable pulley group is movably installed on the mounting base. The fixed pulley group includes a first fixed shaft, and the movable pulley group includes a second fixed shaft. Pulleys are movably installed on both the first fixed shaft and the second fixed shaft. The pulleys can move up and down and rotate. Baffles are fixedly installed at the bottom ends of the first fixed shaft and the second fixed shaft. Springs are arranged on the baffles. The springs are in contact with the baffles, and the top ends of the springs are in contact with the pulleys.

[0013] Preferably, a clamping block is fixedly installed at the top end of the second fixed shaft. A clamping groove is formed at the bottom of the mounting base. The clamping block can be installed inside the clamping groove. When the clamping block is installed inside the clamping groove, the movable pulley group can only move laterally. A fixing screw is also threadedly installed on the mounting base. The fixing screw extends into the clamping groove and is threadedly connected to the clamping block. The clamping block is fixed inside the clamping groove under the action of the fixing screw. In this case, the movable pulley group is fixed to the mounting base.

[0014] Preferably, a connecting component is installed at the top of the mounting base. The connecting component is used to connect the mounting base to the gantry of on-site construction. The connecting component includes a telescopic rod. One end of the telescopic rod is rotatably connected to the mounting base, and the other end of the telescopic rod is rotatably installed with a fixing base. The fixing base can be fixedly connected to the gantry.

[0015] Preferably, the connecting component includes a first connecting rod rotatably connected to the mounting base and a second connecting rod rotatably connected to the fixing base. A second lead screw is rotatably installed on the second connecting rod. The second lead screw is threadedly connected to the first connecting rod. A hexagonal block is fixedly installed on the second lead screw. Two insertion rods are fixedly installed on one side of the second connecting rod. Both of the two insertion rods can be inserted into the inside of the first connecting piece.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) During the movement of the towing cable, the present invention collects the data of the pressure sensor, can real-time monitor the tension change of the towing cable, and provides real-time data support for construction.

[0018] (2) The present invention performs a tension test on the towing cable by the three-point bending method, can accurately measure the tension of the towing cable, and improves the accuracy and reliability of the measurement.

[0019] (3) By rotating the first lead screw and the second lead screw, the present invention can conveniently adjust the vertical displacement of the pressing wheel and the position of the measuring part, making the operation more simple and fast.

[0020] (4) The mounting base of the present invention can rotate, making the device more adaptable to the changes in the traction cable during the traction process and ensuring stable measurement.

[0021] (5) The design of the limiting component of the present invention can play a certain limiting role when the traction cable swings greatly, preventing the traction cable between the two idler wheels from swinging significantly and improving the stability of the measurement.

[0022] (6) The setting of the connection component of the present invention makes it more convenient to install or remove the traction cable from the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the dynamic cable tension testing instrument provided by the present invention;

[0024] Figure 2 is Figure 1 a schematic structural diagram of the pressure wheel assembly in the dynamic cable tension testing instrument provided;

[0025] Figure 3 is Figure 1 a schematic structural diagram of the frame in the dynamic cable tension testing instrument shown;

[0026] Figure 4 is Figure 1 a schematic structural diagram of the mounting base and the mounting frame in the dynamic cable tension testing instrument shown;

[0027] Figure 5 is Figure 4 an enlarged view of part A in;

[0028] Figure 6 is Figure 1 a schematic structural diagram of the moving wheel set in the dynamic cable tension testing instrument shown;

[0029] Figure 7 is Figure 1 a schematic structural diagram of the connection component in the dynamic cable tension testing instrument shown;

[0030] Figure 8 is the schematic diagram of the cable tension calculation principle by the three-point bending method;

[0031] Figure 9 is a schematic diagram of an embodiment of the dynamic cable tension testing instrument provided by the present invention.

[0032] Among them, the names corresponding to the attached drawing reference numerals are as follows: 1 - mounting base, 2 - mounting frame, 3 - supporting wheel, 4 - frame, 5 - pressing wheel, 6 - triangular frame, 7 - pressure sensor, 8 - first lead screw, 9 - fixing plate, 10 - laser rangefinder, 11 - T-shaped block, 12 - T-shaped groove, 13 - nut, 14 - first fixed shaft, 15 - pulley, 16 - second fixed shaft, 17 - baffle, 18 - spring, 19 - clamping block, 20 - clamping groove, 21 - fixing screw, 22 - first connecting rod, 23 - second connecting rod, 24 - second lead screw, 25 - hexagonal block, 26 - inserting rod, 27 - fixing seat. Detailed implementation manners

[0033] The present invention will be further described below in conjunction with the attached drawing illustration and embodiments. The implementation manners of the present invention include but are not limited to the following embodiments.

[0034] Embodiment 1

[0035] As Figures 1-9 shown, the dynamic cable tension testing instrument provided by the present invention includes: a mounting base 1, a mounting frame 2 is fixed to the bottom of the mounting base 1, two supporting wheels 3 are rotatably mounted on one side of the mounting frame 2, the two supporting wheels 3 are at the same level, a pressing wheel assembly is arranged on one side of the mounting frame 2, and the pressing wheel assembly cooperates with the two supporting wheels 3 to press the traction cable to bend. The pressing wheel assembly includes a frame 4, a pressing wheel 5 is rotatably mounted inside the frame 4. During detection, the traction cable is located between the two supporting wheels 3 and the pressing wheel 5. A triangular frame 6 is arranged below the frame 4, a pressure sensor 7 is fixed to the top of the triangular frame 6, the pressure sensor 7 is fixed to the frame 4. A laser rangefinder 10 is also arranged below the frame 4, and the laser rangefinder 10 is used to measure the moving distance of the frame 4. In the initial state, the moving distance of the frame 4 measured by the laser rangefinder 10 is 0. In this case, the traction cable is in contact with the two supporting wheels 3 and the pressing wheel 5, and the traction cable is in a horizontal state. When measuring the tension of the traction cable (as Figure 8 shown), the frame 4 moves and drives the pressing wheel 5 to move, pressing the traction cable to bend, and the bending angle is θ. The moving distance of the frame 4 can be measured by the laser rangefinder 10 and can be defined as L. When the traction cable pulls the stay cable of the bridge, its tension is defined as T, and the length of the traction cable between the two supporting wheels 3 is defined as 2H.

[0036] The following uses the three-point bending method to test the tension of a certain traction cable. The geometric relationship between the traction cable and the test device and the corresponding force decomposition schematic diagram during the test are as Figure 8As shown in the figure. H is the longitudinal distance between the force application points at both ends and the central force application point of the three-point bending test device. This dimension is related to the device structure and can be known data; θ is the tension angle, which reflects the longitudinal pushing-away degree of the traction cable; F is the lateral force exerted by the central force application point on the traction cable. Through force analysis, the relationship between the tension T of the traction cable and F can be obtained:

[0037] F = 2Tsinθ. From the geometric structure of the device, it can be obtained that:

[0038]

[0039] From the above formula, the tension T of the traction cable can be obtained as a functional relationship of the longitudinal force F, the lateral distance H, and the lateral pushing-away distance L of the traction cable.

[0040]

[0041] Since the distance parameters are fixed and the same, T is proportional to F. The force F is obtained by using the pressure sensor 7, and the output signal of the force sensor is processed through the circuit for operation, correction, and amplification. The resulting value is the measured tension T of the traction cable, and the amplification factor is calculated according to the above formula.

[0042] Embodiment 2

[0043] As Figure 2 shown, a fixed plate 9 is fixedly installed on one side of the mounting frame 2. A first lead screw 8 passes through the fixed plate 9, and the first lead screw 8 is threadedly connected to the fixed plate 9. One end of the first lead screw 8 is rotatably connected to the triangular frame 6. When it is necessary to move the frame 4, the first lead screw 8 is rotated to make the triangular frame 6 move upward. The upward movement of the triangular frame 6 drives the frame 4 to move upward through the pressure sensor 7. The movement of the frame 4 drives the pressing wheel 5 to move upward, and the upward movement of the pressing wheel 5 bends the traction cable.

[0044] Furthermore, two nuts 13 are installed on the first lead screw 8. The two nuts 13 are respectively located above and below the fixed plate 9. After the frame 4 moves upward to the specified position, the two nuts 13 are rotated so that both nuts 13 are closely attached to the fixed plate 9. At this time, the first lead screw 8 is fixed under the action of the two nuts 13. In this way, during the measurement process, the first lead screw 8 will not rotate easily, which ensures that the pressing wheel 5 will not move easily, thus ensuring the accuracy of the test.

[0045] Embodiment 3

[0046] As Figures 3-4 shown, a T-shaped block 11 is fixed on one side of the frame 4 close to the mounting frame 2. A T-shaped groove 12 is opened on one side of the mounting frame 2. The T-shaped block 11 can be installed in the T-shaped groove 12. During the movement of the frame 4, the cooperation between the T-shaped block 11 and the T-shaped groove 12 ensures the stable operation of the frame 4.

[0047] Example 4

[0048] As Figure 1 shown, both ends of the mounting base 1 are provided with limiting components. The limiting components include a fixed pulley group and a movable pulley group. The fixed pulley group is fixed to the bottom of the mounting base 1, and the movable pulley group is movably mounted on the mounting base 1. The fixed pulley group includes a first fixed shaft 14, and the movable pulley group includes a second fixed shaft 16. Pulleys 15 are movably mounted on both the first fixed shaft 14 and the second fixed shaft 16. The pulleys 15 can move up and down and rotate. Baffles 17 are fixedly mounted at the bottom ends of the first fixed shaft 14 and the second fixed shaft 16. Springs 18 are arranged on the baffles 17. The springs 18 are in contact with the baffles 17, and the top ends of the springs 18 are in contact with the pulleys 15. During use, the towing cable is located between the two limiting components. When the towing cable swings greatly, the two limiting components can play a certain limiting role on the towing cable, thereby preventing the towing cable between the two supporting pulleys 3 from swinging significantly. The limiting components play a role in limiting the towing cable.

[0049] Furthermore, as Figures 5-6 shown, a clamping block 19 is fixedly mounted at the top end of the second fixed shaft 16, and a clamping groove 20 is formed at the bottom of the mounting base 1. The clamping block 19 can be installed inside the clamping groove 20. When the clamping block 19 is installed inside the clamping groove 20, the movable pulley group can only move laterally. A fixing screw 21 is also threadedly mounted on the mounting base 1. The fixing screw 21 extends into the clamping groove 20 and is threadedly connected to the clamping block 19. The clamping block 19 is fixed inside the clamping groove 20 under the action of the fixing screw 21. In this case, the movable pulley group is fixed on the mounting base 1. When it is necessary to install the towing cable on this device or remove it from this device, first remove the fixing screw 21, and then move the clamping block 19 laterally to remove the movable pulley group. At this time, the towing cable can be installed on this device or removed from this device.

[0050] Example 5

[0051] As Figure 1As shown in the figure, a connection component is installed on the top of the mounting base 1. The connection component is used to connect the mounting base 1 with the gantry during on-site construction. The connection component includes a telescopic rod. One end of the telescopic rod is rotatably connected to the mounting base 1, and the other end of the telescopic rod is rotatably installed with a fixing base 27. The fixing base 27 can be fixedly connected to the gantry. In this embodiment, the mounting base 1 can rotate, so that the device can better adapt to the changes during the traction process of the traction cable. During the traction process of the traction cable, it has a certain swing amplitude in the vertical direction, and the rotation of the mounting base 1 enables the idler wheel 3 and the pressure wheel 5 to follow the swing and movement of the traction cable, so that the traction cable can be measured at all times, ensuring that the measurement can be carried out stably.

[0052] Further, as Figure 7 shown, the connection component includes a first connecting rod 22 rotatably connected to the mounting base 1 and a second connecting rod 23 rotatably connected to the fixing base 27. A second lead screw 24 is rotatably installed on the second connecting rod 23. The second lead screw 24 is threadedly connected to the first connecting rod 22. A hexagonal block 25 is fixedly installed on the second lead screw 24. When it is necessary to rotate the second lead screw 24, a wrench is used to clamp on the hexagonal block 25 and rotate the wrench to rotate the second lead screw 24. By rotating the second lead screw 24, the distance between the first connecting rod 22 and the second connecting rod 23 can be adjusted. During actual measurement, the fixing base 27 needs to be installed on the gantry first, and then the traction cable needs to be installed at the specified position. However, if the connection component is relatively long, the installation will be more laborious. On the contrary, if it is relatively short, it will be convenient to install the traction cable. Therefore, during use, first rotate the second lead screw 24 to adjust the distance between the first connecting member 22 and the second connecting member 23 to the minimum. Then, install the traction cable. After the traction cable is installed, rotate the second lead screw 24 again to increase the distance between the first connecting member 22 and the second connecting member 23, so that the device is not affected by the gantry during use. Two insertion rods 26 are fixedly installed on one side of the second connecting rod 23. Both of the two insertion rods 26 can be inserted into the first connecting member 22 and play a role in limiting the first connecting rod 22, ensuring that the first connecting rod 22 can move stably during the rotation of the second lead screw 24.

[0053] Detection method:

[0054] (1) First, stop the movement of the traction cable installed on the gantry and install this device on the gantry;

[0055] (2) Rotate the first lead screw 8 to adjust the vertical displacement of the pressure wheel 5 (the adjustment distance can be 2 cm);

[0056] (3) Then let the traction cable move, and then calculate the traction cable tension by inversely calculating the real-time data curve of the vertical displacement and the compressive stress detected by the pressure sensor.

[0057] Working principle: When in use, first adjust the distance between the first connecting rod 22 and the second connecting rod 23 to the minimum, and ensure that the displacement of the pressure wheel 5 is 0. Then install the entire device on the gantry. Next, remove the two moving wheel sets, install the traction cable between the two supporting wheels 3 and the pressure wheel 5, and then install the moving wheel sets back on the mounting seat 1. At this time, the two pulleys 15 should be clamped on both sides of the traction cable. Then rotate the first lead screw 8 to adjust the pressure wheel 5 to an appropriate distance. Finally, rotate the second lead screw 24 to position the measuring part in place. During the movement of the traction cable, collect the data of the pressure sensor and calculate the tension of the traction cable.

Claims

1. A dynamic cable tension testing instrument, characterized in that, Comprising: A mounting base (1), a mounting frame (2) is fixed to the bottom of the mounting base (1), two supporting wheels (3) are rotatably mounted on one side of the mounting frame (2), the two supporting wheels (3) are at the same horizontal level, a pressing wheel assembly is arranged on one side of the mounting frame (2), the pressing wheel assembly includes a frame (4), a pressing wheel (5) is rotatably mounted inside the frame (4), a triangular frame (6) is arranged below the frame (4), a pressure sensor (7) is fixed to the top of the triangular frame (6), the pressure sensor (7) is fixed to the frame (4), and a laser rangefinder (10) is also arranged below the frame (4); Limit assemblies are mounted at both ends of the mounting base (1), each limit assembly includes a fixed wheel set and a moving wheel set, the fixed wheel set is fixed to the bottom of the mounting base (1), the moving wheel set is movably mounted on the mounting base (1), the fixed wheel set includes a first fixed shaft (14), the moving wheel set includes a second fixed shaft (16), pulleys (15) are movably mounted on both the first fixed shaft (14) and the second fixed shaft (16), baffles (17) are fixedly mounted at the bottom ends of the first fixed shaft (14) and the second fixed shaft (16), a spring (18) is arranged on the baffle (17), the spring (18) is in contact with the baffle (17), and the top end of the spring (18) is in contact with the pulley (15); A clamping block (19) is fixedly mounted at the top end of the second fixed shaft (16), a clamping groove (20) is formed in the bottom of the mounting base (1), and a fixing screw (21) is also threadedly mounted on the mounting base (1), the fixing screw (21) extends into the clamping groove (20) and is threadedly connected to the clamping block (19); A connecting assembly is mounted on the top of the mounting base (1), the connecting assembly includes a telescopic rod, one end of the telescopic rod is rotatably connected to the mounting base (1), and the other end of the telescopic rod is rotatably mounted with a fixing base (27), and the fixing base (27) can be fixedly connected to a gantry; The connecting assembly includes a first connecting rod (22) rotatably connected to the mounting base (1) and a second connecting rod (23) rotatably connected to the fixing base (27), a second lead screw (24) is rotatably mounted on the second connecting rod (23), the second lead screw (24) is threadedly connected to the first connecting rod (22), a hexagonal block (25) is fixedly mounted on the second lead screw (24), and two insertion rods (26) are fixedly mounted on one side of the second connecting rod (23), and both of the two insertion rods (26) can be inserted into the first connecting member (22).

2. The dynamic cable tension testing instrument according to claim 1, characterized in that, A fixing plate (9) is fixedly mounted on one side of the mounting frame (2), a first lead screw (8) passes through the fixing plate (9), the first lead screw (8) is threadedly connected to the fixing plate (9), and one end of the first lead screw (8) is rotatably connected to the triangular frame (6).

3. The dynamic cable tension testing instrument according to claim 2, wherein, Two nuts (13) are mounted on the first lead screw (8), and the two nuts (13) are respectively located above and below the fixing plate (9).

4. The dynamic cable tension testing instrument according to claim 1, wherein, One side of the frame (4) close to the mounting bracket (2) is fixedly provided with a T-shaped block (11), and a T-shaped groove (12) is formed on one side of the mounting bracket (2), and the T-shaped block (11) can be installed in the T-shaped groove (12).

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