An angle measuring device for a cast-in-place box girder

Abstract

The present application belongs to box girder measurement technical field, disclose a kind of angle measurement equipment of cantilever box girder, including mounting seat and shell, further include self-balancing adjusting assembly, gravity pendulum rod, intelligent angle sensor and damping component, the shell is cylindrical hollow structure, the self-balancing adjusting assembly is set in shell interior, and static friction at self-balancing adjusting assembly rotating fulcrum is converted into dynamic friction by pulse vibration energy, the gravity pendulum rod is set on self-balancing adjusting assembly and includes upper section, middle section and lower section, the upper section is used to absorb high-frequency stress wave, the intelligent angle sensor is set in gravity pendulum rod interior and located at middle section place.The self-balancing adjusting assembly, gravity pendulum rod and damping component of the present application are set, can improve the measurement sensitivity of intelligent angle sensor on the basis of avoiding construction site environmental interference, effectively guarantee the accuracy of measurement result.

Description

Technical Field

[0001] This invention belongs to the field of box girder measurement technology, specifically an angle measuring device for cantilever box girders. Background Technology

[0002] A cantilever box girder is a prestressed concrete box girder constructed using the cantilever casting method. After casting, its dimensions need to be measured, including the length of the top plate, the length of the bottom plate, the height of the box girder, the inclination of the top plate, and the angle of the bottom of the box girder.

[0003] Traditional measurement processes rely heavily on manual calibration and measurement, which not only increases the difficulty of measurement but also severely limits its efficiency. Furthermore, manual measurement is prone to errors. To address these issues, existing technologies offer better solutions, such as the angle measurement device for cast-in-place box girders (publication number CN118794395B). This device uses two flexible follow-up mechanisms to achieve flexible contact with the box girder body, avoiding damage caused by rigid contact between the measuring mechanism and the box girder body. It also facilitates measurement actions during movement, thereby improving the accuracy of the measurement results. However, the following drawbacks remain: Currently, measurement technologies applied in bridge construction and hanging basket attitude monitoring are mainly divided into two categories: contact measurement and non-contact measurement. Contact displacement and angle measurement devices include intelligent sensors such as displacement gauges, inclinometers, levels, and long-gauge strain sensors. However, construction sites present strong mechanical vibrations, significant temperature differences, high concentrations of dust, and confined working spaces. Traditional equipment using damping often suffers from return hysteresis and measurement dead zones, where the viscous force of the damping medium prevents the gravity pendulum from fully returning to its original position under small displacements, thus limiting measurement accuracy.

[0004] Therefore, in order to solve the above problems, an angle measuring device for cantilever box girders is proposed. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the existing technology by providing an angle measuring device for cantilever box girders, thereby solving the problems of return delay and measurement dead zone caused by the complex environment of the construction site and the traditional damping and vibration reduction methods.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An angle measuring device for a cantilever box girder includes a mounting base and a housing. The housing is fixedly mounted on the bottom of the mounting base and also includes a self-balancing adjustment component, a gravity pendulum, an intelligent angle sensor, and a damping component. The housing has a cylindrical hollow structure. The self-balancing adjustment component is located inside the housing and uses pulse vibration energy to convert static friction at the pivot point of the self-balancing adjustment component into dynamic friction, thereby eliminating the measurement dead zone. The gravity pendulum is mounted on the self-balancing adjustment component and includes an upper section, a middle section, and a lower section. The upper section is used to absorb high-frequency stress waves. The intelligent angle sensor is located inside the gravity pendulum and in the middle section. The damping component is located inside the housing and in the lower section. The lower section is used to form a heat conduction path between the gravity pendulum and the damping component.

[0007] Preferably, the self-balancing adjustment assembly includes an outer ring frame and an inner ring frame. The outer ring frame is located in the upper half of the interior of the housing and has a rotating shaft on its outer wall. The rotating shaft is rotatably fitted with a bearing seat, which is fixedly connected to the inner wall of the housing. The outer wall of the inner ring frame has a rotating shaft, which is rotatably fitted with a bearing seat, which is fixedly connected to the inner wall of the outer ring frame. The planes containing the central axes of the rotating shaft and the rotating shaft are parallel to each other, and the angle between their central axes is 90°. The rotational bearing clearance between the rotating shaft and the bearing seat and between the rotating shaft and the bearing seat is 8-12 micrometers.

[0008] Preferably, the upper end of the gravity pendulum is provided with a connecting rod, and is fixedly connected to the inner ring frame through the connecting rod. The middle section has an inner cavity with an elliptical cross section along the axial direction of the gravity pendulum. The intelligent angle sensor is set in the inner cavity. The upper section has a through hole communicating with the inner cavity, and the lower section has a groove communicating with the inner cavity. The inner diameter of the through hole is smaller than the inner diameter of the groove.

[0009] Preferably, the damping assembly includes an annular partition, a flexible insulating bellows, and an annular plate. The annular partition is fixedly installed inside the outer shell and divides the interior of the outer shell into an upper chamber and a lower chamber. Both the outer ring frame and the inner ring frame are installed in the upper chamber. The lower chamber is filled with damping oil. The gravity pendulum passes through the annular partition and its lower section extends into the damping oil. The flexible insulating bellows is movably sleeved on the gravity pendulum. The annular plate is fixedly sleeved on the gravity pendulum. The upper end of the flexible insulating bellows is fixedly connected to the annular partition, and the lower end is fixedly connected to the annular plate. The flexible insulating bellows is made of fluorosilicone rubber.

[0010] Preferably, the wall thickness of the upper section is greater than that of the lower section, and the ratio of the wall thickness of the upper section to that of the lower section is set to 3-5:1.

[0011] Preferably, the inner wall of the lower chamber is arrayed with hemispherical turbulence grooves, which are located below the surface of the damping oil. The outer wall of the lower section is provided with spiral guide grooves, and there are two spiral guide grooves arrayed circumferentially along the lower section. Both spiral guide grooves are immersed in the damping oil.

[0012] Preferably, an annular elastic compensation oil bladder is provided at the bottom of the annular partition. The annular elastic compensation oil bladder can be a thin film elastomer made of highly elastic, oil-resistant fluororubber or modified acrylic rubber. The inner diameter of the annular elastic compensation oil bladder is larger than the inner diameter of the annular partition, and an air tube is provided at the top. The upper end of the air tube passes through the annular partition to the upper chamber.

[0013] Preferably, the annular plate is located at the connection between the middle section and the lower section, and the interior of the flexible isolation corrugated pipe is connected to the upper chamber.

[0014] Compared with the prior art, the present invention has the following advantages: 1. This invention, through the self-balancing adjustment component, utilizes a dual-degree-of-freedom omnidirectional suspension structure composed of an outer ring frame and an inner ring frame. Combined with the pulse vibration energy at the construction site, it transforms the static friction at the rotation fulcrum of the outer and inner ring frames into dynamic friction. This eliminates the measurement dead zone at its source, solving the problem that the gravity pendulum cannot quickly reset under small displacements due to the viscous force of the damping medium. This achieves the effect of eliminating the measurement dead zone, effectively improving the sensitivity of the intelligent angle sensor, thereby ensuring the measurement accuracy of the measuring equipment in the construction environment.

[0015] 2. This invention, by setting the gravity pendulum rod into upper, middle, and lower sections, utilizes a segmented design and an elliptical internal cavity structure to effectively absorb and reflect high-frequency stress waves. Simultaneously, by setting the proportional thickness of the upper and lower sections, it effectively filters out burr noise generated by strong mechanical vibrations at the construction site, protecting the internal intelligent angle sensor from high-frequency impacts. This not only improves the signal-to-noise ratio of the measurement data but also enhances the stress distribution of the gravity pendulum rod during dynamic swinging, ensuring the mechanical stability of the intelligent angle sensor in harsh physical environments.

[0016] 3. This invention, through the design of a flexible isolation bellows and an elastic compensation oil bladder, can suppress low-frequency shaking and completely isolate the damping oil from contaminating the working space of the intelligent angle sensor. At the same time, it can also use the pleated deformation of the flexible isolation bellows to compensate for the displacement of the gravity pendulum, avoiding the high frictional resistance caused by traditional sealing methods. In addition, combined with the heat conduction effect of the gravity pendulum and the pressure relief effect of the air pipe, it effectively solves the secondary interference of damping oil expansion and pressure fluctuation caused by temperature difference on measurement accuracy, further ensuring the accuracy of measurement results. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the connection structure between the outer shell, the self-balancing adjustment component, and the damping component of the present invention; Figure 3 This is a schematic diagram of the gravity pendulum of the present invention; Figure 4 This is a cross-sectional view of the connection structure between the gravity pendulum and the intelligent angle sensor of the present invention. Figure 5 This is a schematic diagram of the connection structure between the self-balancing adjustment component and the gravity pendulum of the present invention; Figure 6 This is a schematic diagram of the connection structure between the outer shell, the damping component, and the gravity pendulum rod of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1. Mounting base; 2. Outer shell; 21. Upper chamber; 22. Lower chamber; 221. Hemispherical turbulence channel; 3. Self-balancing adjustment assembly; 31. Outer ring frame; 311. Rotating shaft one; 312. Bearing seat one; 32. Inner ring frame; 321. Rotating shaft two; 322. Bearing seat two; 4. Gravity swing arm; 41. Upper section; 411. Through hole; 42. Middle section; 421. Inner cavity; 43. Lower section; 431. Groove; 432. Spiral guide channel; 44. Connecting rod; 5. Intelligent angle sensor; 6. Damping assembly; 61. Annular partition; 611. Annular elastic compensation oil bladder; 612. Air pipe; 62. Flexible isolation corrugated pipe; 63. Annular plate. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0020] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5The device shown is an angle measuring device for a cantilever box girder, comprising a mounting base 1 and a housing 2. The mounting base 1 can be installed on the core load-bearing component in the construction of the cantilever box girder via a flange, preferably on the longitudinal beam of the hanging basket or the reinforcing steel of the cantilever section. The housing 2 is fixedly installed at the bottom of the mounting base 1 and also includes a self-balancing adjustment component 3, a gravity pendulum 4, and an intelligent angle sensor 5. The gravity pendulum 4 is mounted on the self-balancing adjustment component 3. The housing 2 has a cylindrical hollow structure. The self-balancing adjustment component 3 is located inside the housing 2 and includes an outer ring frame 31 and an inner ring frame 32. The outer ring frame 31 is located in the upper half of the interior of the housing 2. Furthermore, a rotating shaft 311 is provided on the outer wall, and a bearing seat 312 is rotatably fitted on the rotating shaft 311. The bearing seat 312 is fixedly connected to the inner wall of the outer shell 2. A rotating shaft 321 is provided on the outer wall of the inner ring frame 32, and a bearing seat 322 is rotatably fitted on the rotating shaft 321. The bearing seat 322 is fixedly connected to the inner wall of the outer ring frame 31. The planes containing the central axes of the rotating shaft 311 and the rotating shaft 321 are parallel to each other, and the angle between their central axes is 90°. The rotational bearing fit clearance between the rotating shaft 311 and the bearing seat 312, and between the rotating shaft 321 and the bearing seat 322, is 8-12 micrometers.

[0021] Traditional tilt measurement equipment introduces initial errors when the mounting surface is not level, and due to friction, the gravity pendulum cannot reset under slight displacement, creating a measurement dead zone and affecting the accuracy of the measurement results. Therefore, by adopting the above-described implementation, when the outer ring frame 31 deflects, its rotating shaft 311, through a rotating sleeve between itself and the bearing seat 312 inside the outer casing 2, provides the outer ring frame 31 with a degree of freedom of rotation along the axis of the rotating shaft 311. Similarly, when the inner ring frame 32 deflects, its rotating shaft 321, through a rotating sleeve between itself and the bearing seat 322 on the outer ring frame 31, provides the inner ring frame 32 with a degree of freedom of rotation along the axis of the rotating shaft 321. This achieves a dual-degree-of-freedom omnidirectional suspension installation structure for the gravity pendulum 4, thereby offsetting horizontal deviations in all directions of the installation position; regardless of the construction of the cantilever box girder... No matter how complex the working environment, the internal gravity pendulum 4 can always be kept in a free hanging state, which greatly improves the environmental adaptability and automatic leveling capability of the equipment. Furthermore, under the action of pulse vibration energy at the construction site, the 8-12 micrometer rotation bearing fit clearance between the rotating shaft 311 and bearing seat 312, and between the rotating shaft 321 and bearing seat 322, can ensure that the gravity pendulum 4 will not experience violent axial or radial jumps when the measuring equipment is subjected to external impacts or severe vibrations. It can also ensure that the gravity pendulum 4 can immediately overcome the negative impact of friction when the angle changes slightly, thereby ensuring the accuracy of the measurement results by eliminating the measurement dead zone.

[0022] As one embodiment of the present invention, refer to Figure 2 , Figure 3 and Figure 4 The gravity pendulum 4 includes an upper section 41, a middle section 42, and a lower section 43. The intelligent angle sensor 5 is disposed inside the gravity pendulum 4 and located at the middle section 42. A connecting rod 44 is provided at the upper end of the gravity pendulum 4, and is fixedly connected to the inner ring frame 32 through the connecting rod 44, thereby forming a two-stage suspension of the gravity pendulum 4. The connecting rod 44, as a connecting component, can provide a small elastic buffer between the inner ring frame 32 and the gravity pendulum 4, further reducing the mechanical impact from the mounting base. The middle section 42 has an inner cavity 421 with an elliptical cross section along the axial direction of the gravity pendulum 4. The intelligent angle sensor 5 is disposed in the inner cavity 421. The upper section 41 has a through hole 411 communicating with the inner cavity 421. The lower section 43 has a groove 431 communicating with the inner cavity 421. The inner diameter of the through hole 411 is smaller than the inner diameter of the groove 431.

[0023] Due to the severe mechanical vibrations at the construction site of the cantilever box girder, if the gravity pendulum 4 is a solid rod, the high-frequency stress waves will be directly transmitted to the intelligent angle sensor 5, resulting in burrs or high-frequency noise in the output data of the intelligent angle sensor 5. Furthermore, since the intelligent angle sensor 5 is located inside the gravity pendulum 4, when the gravity pendulum 4 swings or is affected by vibration, the uneven stress distribution at the location of the intelligent angle sensor 5 will also affect its mechanical stability.

[0024] Therefore, by adopting the above-described implementation method, on the one hand, the inner cavity 421 inside the middle section 42 is set to an elliptical cross section along the axial direction of the gravity pendulum 4. Compared with a square or irregular cavity, the elliptical structure can more effectively disperse stress, thereby improving the mechanical strength and fatigue life of the middle section 42 of the gravity pendulum 4. At the same time, the elliptical shape can also reduce the radial cross-sectional area of ​​the gravity pendulum 4 at the middle section 42 while ensuring the lateral space of the intelligent angle sensor 5, so that the center of gravity of the gravity pendulum 4 is closer to the bottom, thereby improving the swing sensitivity and reset accuracy of the gravity pendulum 4. On the other hand, since there is an abrupt change in cross-sectional area at the connection between the through hole 411 and the inner cavity 421, when the high-frequency stress wave passes through the connection between the through hole 411 and the inner cavity 421, it will be reflected and attenuated, thereby protecting the intelligent angle sensor 5 installed in the inner cavity 421 from interference by the high-frequency stress wave; and since the inner diameter of the groove 431 at the lower end is larger than the inner diameter of the through hole 411, according to the principle of heat conduction, it can help guide the heat in the through hole 411 and the inner cavity 421 to flow downward, thereby achieving the cooling treatment of the intelligent angle sensor 5 and avoiding heat accumulation that would affect the lifespan and measurement accuracy of the intelligent angle sensor 5.

[0025] As one embodiment of the present invention, refer to Figure 1 , Figure 2 , Figure 5 and Figure 6 It also includes a damping component 6, which is disposed inside the outer shell 2 and located at the lower section 43. The damping component 6 includes an annular partition 61, a flexible isolation bellows 62, and an annular plate 63. The annular partition 61 is fixedly disposed inside the outer shell 2 and divides the inner shell 2 into an upper chamber 21 and a lower chamber 22. The outer ring frame 31 and the inner ring frame 32 are both disposed in the upper chamber 21. The lower chamber 22 is filled with damping oil. The gravity pendulum 4 passes through the annular partition 61 and the lower section 43 extends into the damping oil. The flexible isolation bellows 62 is movably sleeved on the gravity pendulum 4. The annular plate 63 is fixedly sleeved on the gravity pendulum 4. The upper end of the flexible isolation bellows 62 is fixedly connected to the annular partition 61, and the lower end is fixedly connected to the annular plate 63. The flexible isolation bellows 62 is made of fluorosilicone rubber.

[0026] Because the construction of the cantilever box girder is accompanied by strong low-frequency swaying, damping oil is needed to suppress the ineffective swaying of the gravity pendulum 4. However, the traditional sealing method has high friction, which will hinder the free swinging process of the gravity pendulum 4. At the same time, because the damping oil is volatile and fluid, if the sealing effect is not good, oil gas will enter the upper chamber 21, which will not only contaminate the intelligent angle sensor 5, but also enter the connection between the first rotating shaft 311 and the first bearing seat 312, and between the second rotating shaft 321 and the second bearing seat 322, causing the intelligent angle sensor 5 to fail or increase mechanical damping.

[0027] Therefore, by adopting the above-described implementation method, on the one hand, during the swing of the gravity pendulum 4, the annular plate 63 installed on it will move synchronously with the gravity pendulum 4. Since the flexible isolation bellows 62 is fixedly installed between the annular partition 61 and the annular plate 63, during the swing of the gravity pendulum 4 and the annular plate 63, the flexible isolation bellows 62 can compensate for the displacement of the gravity pendulum 4 through its own fold deformation, thereby reducing the frictional force generated by the need for sealing, ensuring that the gravity pendulum 4 can still respond quickly when there is a small angle change, and maintaining extremely high measurement sensitivity; and, due to the presence of the flexible isolation bellows 62, it can be ensured that the self-balancing adjustment component 3 and the intelligent angle sensor 5 are always in a dry environment without oil and gas interference, so that the damping oil is retained below the partition, and even if the entire measuring device tilts or bumps to a certain extent, the damping oil will not overflow. On the other hand, the flexible isolation bellows 62 made of fluorosilicone rubber has high oil resistance, so that it will not swell even if it is in contact with damping oil for a long time; it also has extremely low elastic modulus, so that the gravity pendulum 4 will not be affected by resistance when swinging at a small angle, further ensuring the measurement accuracy of the intelligent angle sensor 5 set inside the gravity pendulum 4.

[0028] As one embodiment of the present invention, refer to Figure 3 and Figure 4 The wall thickness of the upper section 41 is greater than that of the lower section 43, and the ratio of the wall thickness of the upper section 41 to that of the lower section 43 is set to 3-5:1. If the ratio is less than 3:1, the impedance mismatch effect will be poor, and the high-frequency stress wave will still be transmitted to the intelligent angle sensor 5 along the gravity pendulum 4. If the ratio is greater than 5:1, the wall of the lower section 43 of the gravity pendulum 4 will be too thin, and under the viscous resistance of the damping oil, there may be slight deformation or mechanical fatigue, which will affect the structural stability of long-term measurement.

[0029] By adopting the above-described implementation method, the thicker and heavier upper section 41 can have greater mechanical inertia. When high-frequency, minute vibration waves are transmitted from the top of the gravity pendulum 4, the upper section 41, due to its larger mass, can absorb and reflect most of the high-frequency stress waves. When a small portion of the high-frequency stress waves enters the through hole 411, the energy of the high-frequency stress waves can be rapidly attenuated by utilizing the thickness variations of the upper section 41, the middle section 42, and the lower section 43, thus avoiding interference with the intelligent angle sensor 5. At the same time, since the lower section 43 has a smaller wall thickness and extends partially into the damping oil, the heat generated by the intelligent angle sensor 5 during operation can be absorbed by the damping oil through thermal conduction. This not only cools down the intelligent angle sensor 5 but also protects the top self-balancing adjustment component 3 from mechanical errors caused by thermal expansion, further ensuring the accuracy of the measurement results.

[0030] As one embodiment of the present invention, refer to Figure 5 and Figure 6 The lower chamber 22 has hemispherical turbulence grooves 221 arrayed on its peripheral inner wall. The hemispherical turbulence grooves 221 are located below the surface of the damping oil. The lower section 43 has spiral guide grooves 432 arranged on its outer wall. There are two spiral guide grooves 432 arrayed along the circumference of the lower section 43. Both spiral guide grooves 432 are immersed in the damping oil.

[0031] Because damping oil tends to form a stable laminar flow in a smooth cavity, and the resistance generated by laminar flow is relatively small, it absorbs energy slowly under intense high-frequency vibration conditions during construction, resulting in a longer time for the intelligent angle sensor 5 reading to recover to a stable state. At the same time, when the gravity pendulum 4 vibrates at high speed and with small amplitude in the damping oil, it causes drastic changes in local pressure, which easily generates tiny bubbles. This not only changes the compressibility and viscosity of the damping oil, but also makes the damping force of the damping oil unstable, thus affecting the measurement accuracy. Therefore, by adopting the above-described implementation method, using the hemispherical turbulence groove 221 and the spiral guide groove 432, when the damping oil flows on the inner wall surface of the sealed shell 2 as the gravity pendulum 4 swings, the hemispherical turbulence groove 221 will induce small micro-vortices, causing the fluid to change from laminar flow to turbulent flow, thereby increasing energy consumption; while during the swinging process of the gravity pendulum 4, the spiral guide groove 432 on its surface will drive the damping oil to flow in a spiral direction. At this time, the fixed hemispherical turbulence groove 221 will obstruct the flow of oil, induce small vortices, and cause the fluid state to quickly change from laminar flow to turbulent flow, preventing viscosity fluctuations caused by local overheating of the damping oil and maintaining the long-term stability of the damping characteristics of the damping oil.

[0032] As one embodiment of the present invention, refer to Figure 4 and Figure 6 The bottom of the annular partition 61 is provided with an annular elastic compensation oil bladder 611. The annular elastic compensation oil bladder 611 can be a thin film elastomer made of highly elastic, oil-resistant fluororubber or modified acrylic rubber. It can ensure that the entire service life of the measuring equipment will not be damaged by damping oil corrosion, thus avoiding the risk of damping oil leakage and contamination of the internal intelligent angle sensor 5, and ensuring the long-term high reliability of the equipment. The inner diameter of the annular elastic compensation oil bladder 611 is larger than the inner diameter of the annular partition 61, and an air pipe 612 is provided at the top. The upper end of the air pipe 612 passes through the annular partition 61 to the upper chamber 21.

[0033] By adopting the above-described implementation method, when the damping oil expands and compresses the annular elastic compensation oil bladder 611, the gas inside the annular elastic compensation oil bladder 611 is discharged to the upper chamber 21 through the air pipe 612. Since the upper chamber 21 has a relatively large volume, the gas in the annular elastic compensation oil bladder 611 will not cause a significant increase in the air pressure inside the upper chamber 21 after entering the upper chamber 21, thus not generating additional elastic resistance to the gravity pendulum 4, enabling the intelligent angle sensor 5 to maintain extremely high measurement sensitivity.

[0034] As one embodiment of the present invention, refer to Figure 3 and Figure 6The annular plate 63 is located at the connection between the middle section 42 and the lower section 43. If the installation position of the annular plate 63 is too high, it will interfere with the installation environment of the intelligent angle sensor 5 at the middle section 42. If the installation position of the annular plate 63 is too low, it will cause the gravity pendulum 4 to generate an excessive bending moment when it is impacted, which can easily cause deformation of the gravity pendulum 4 or wear at the rotating connection. The interior of the flexible isolation bellows 62 is connected to the upper chamber 21. By connecting the two, the air pressure inside the flexible isolation bellows 62 can always be kept consistent with that inside the upper chamber 21, so that the gravity pendulum 4 is only subject to its own weight and the damping constraint of the damping oil during the swing, which further ensures the accuracy of the measurement results.

[0035] like Figures 1-6 As shown, the working principle of this invention is as follows: When the vibration generated at the construction site of the cantilever box girder causes the measuring equipment to swing, the outer ring frame 31 set inside the outer shell 2 is connected to the bearing seat 312 through the rotating shaft 311, and the inner ring frame 32 is connected to the bearing seat 322 through the rotating shaft 321. This constructs a double-degree-of-freedom universal suspension structure. Under the action of the pulse vibration energy at the construction site, the static friction at the fulcrum is converted into dynamic friction, so that the gravity pendulum 4 is suspended on the inner ring frame 32 through the connecting rod 44 and automatically finds the verticality to eliminate the measurement dead zone. During this process, the intelligent angle sensor 5 installed in the inner cavity 421 collects angle signals in real time. Since the ratio of the wall thickness of the upper section 41 to the lower section 43 of the gravity swing rod 4 is set to 3-5:1, in conjunction with the through hole 411 penetrating the upper section 41 and the groove 431 installed in the lower section 43, it can absorb and reflect the high-frequency stress wave transmitted from the top of the gravity swing rod 4, and the stress is dispersed by the inner cavity 421 with an elliptical cross section to ensure that the working environment of the intelligent angle sensor 5 is not disturbed. Meanwhile, the lower section 43 of the gravity pendulum 4 utilizes the spiral guide groove 432 on its outer wall and the hemispherical turbulence groove 221 arrayed on the inner wall of the lower chamber 22 to induce laminar flow into turbulent flow during the movement of the gravity pendulum 4, thereby increasing energy consumption. Damping oil suppresses the ineffective re-swing of the gravity pendulum 4 under low-frequency swaying. At the same time, the annular partition 61 and the flexible isolation bellows 62 physically isolate the upper chamber 21 and the lower chamber 22, ensuring that the intelligent angle sensor 5 is in a dry environment free from oil and gas interference. The flexible isolation bellows 62 compensates for the displacement of the gravity pendulum 4 through its own pleated deformation, thereby eliminating the frictional resistance of the traditional sealing structure. The annular elastic compensation oil bladder 611 set at the bottom of the annular partition 61 can flexibly balance and release the oil pressure generated by the thermal expansion of the damping oil in conjunction with the air pipe 612. Ultimately, it achieves high-sensitivity and high-stability real-time angle monitoring in complex construction environments, effectively ensuring the accuracy of the measurement results.

Claims

1. An angle measuring device for a cantilever box girder, comprising a mounting base (1) and a cylindrical hollow shell (2), characterized in that: The outer shell (2) is provided with a self-balancing adjustment component (3). The gravity pendulum (4) is provided on the self-balancing adjustment component (3) and includes an upper section (41), a middle section (42) and a lower section (43). The upper section (41) is used to absorb high-frequency stress waves. The middle section (42) is provided with an intelligent angle sensor (5). The lower section (43) is provided with a damping component (6). The lower section (43) is used to form a heat conduction path between the gravity pendulum (4) and the damping component (6).

2. The angle measuring device for a cantilevered box girder according to claim 1, characterized in that: The self-balancing adjustment component (3) includes an outer ring frame (31) and an inner ring frame (32). The outer ring frame (31) is located in the upper half of the interior of the outer shell (2) and has a rotating shaft (311) on its outer wall. The rotating shaft (311) is rotatably fitted with a bearing seat (312). The bearing seat (312) is fixedly connected to the inner wall of the outer shell (2). The outer wall of the inner ring frame (32) has a rotating shaft (321) on its outer wall. The rotating shaft (321) is rotatably fitted with a bearing seat (322). The bearing seat (322) is fixedly connected to the inner wall of the outer ring frame (31). The planes on which the central axes of the rotating shaft (311) and the rotating shaft (321) are located are parallel to each other, and the angle between their central axes is 90°. The rotation bearing fit clearance between the rotating shaft (311) and the bearing seat (312) and between the rotating shaft (321) and the bearing seat (322) is 8-12 micrometers.

3. The angle measuring device for a cantilevered box girder according to claim 2, characterized in that: The upper end of the gravity pendulum (4) is provided with a connecting rod (44), and is fixedly connected to the inner ring frame (32) through the connecting rod (44). The middle section (42) has an inner cavity (421) with an elliptical cross section along the axial direction of the gravity pendulum (4). The intelligent angle sensor (5) is located in the inner cavity (421). The upper section (41) has a through hole (411) that communicates with the inner cavity (421). The lower section (43) has a groove (431) that communicates with the inner cavity (421). The inner diameter of the through hole (411) is smaller than the inner diameter of the groove (431).

4. The angle measuring device for a cantilevered box girder according to claim 3, characterized in that: The wall thickness of the upper section (41) is greater than that of the lower section (43), and the ratio of the wall thickness of the upper section (41) to that of the lower section (43) is set to 3-5:

1.

5. The angle measuring device for a cantilevered box girder according to claim 2, characterized in that: The damping assembly (6) includes an annular partition (61), a flexible isolation bellows (62), and an annular plate (63). The annular partition (61) is fixedly installed inside the outer shell (2) and divides the interior of the outer shell (2) into an upper chamber (21) and a lower chamber (22). The outer ring frame (31) and the inner ring frame (32) are both installed in the upper chamber (21). The lower chamber (22) is filled with damping oil. The gravity pendulum (4) passes through the annular partition (61) and its lower section (43) extends into the damping oil. The flexible isolation bellows (62) is movably sleeved on the outside of the gravity pendulum (4). The upper end of the flexible isolation bellows (62) is fixedly connected to the annular partition (61), and the lower end of the flexible isolation bellows (62) is fixedly connected to the annular plate (63). The annular plate (63) is fixedly sleeved on the gravity pendulum (4).

6. The angle measuring device for a cantilevered box girder according to claim 5, characterized in that: The lower chamber (22) has a hemispherical turbulence groove (221) arrayed on its peripheral inner wall. The hemispherical turbulence groove (221) is located below the surface of the damping oil. The lower section (43) has a spiral guide groove (432) arranged on its outer wall. There are two spiral guide grooves (432) arranged in a circumferential array along the lower section (43), and both spiral guide grooves (432) are immersed in the damping oil.

7. The angle measuring device for a cantilevered box girder according to claim 5, characterized in that: The bottom of the annular partition (61) is provided with an annular elastic compensation oil bladder (611), the inner diameter of the annular elastic compensation oil bladder (611) is larger than the inner diameter of the annular partition (61), and the top is provided with an air tube (612), the upper end of the air tube (612) passes through the annular partition (61) to the upper chamber (21).

8. The angle measuring device for a cantilevered box girder according to claim 5, characterized in that: The annular plate (63) is located at the connection between the middle section (42) and the lower section (43), and the interior of the flexible isolation corrugated pipe (62) is connected to the upper chamber (21).

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