Device and method for detecting friction performance of bidirectional counter-force type pushing mechanism

Abstract

The invention discloses a bidirectional counter-force type pushing mechanism friction performance detection device and method, the device comprises a counter-force frame, a pushing mechanism, a loading oil cylinder group and a detection assembly, a sliding friction pair is arranged between the pushing mechanism and a structural beam, and the detection assembly comprises various high-precision sensors and detection equipment. The method is based on the device, and the friction durability is evaluated according to the maximum cycle index of a contact surface without obvious defects by replacing different anti-friction parts, applying gradient vertical load and horizontal traction force, collecting related data to calculate the friction coefficient, evaluating the motion smoothness, screening adaptive anti-friction parts and then carrying out cycle test. According to the invention, the actual working condition can be accurately simulated, the detection reliability is improved, the construction test risk is avoided, support is provided for design optimization and fault prediction of the pushing mechanism, and both economic benefits and social benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of jacking mechanism testing technology, specifically to a bidirectional reaction force jacking mechanism friction performance testing device and method. Background Technology

[0002] In the construction of long-span steel bridges, jacking is a core technology, primarily encompassing drag-type multi-point continuous jacking, wedge-type multi-point continuous jacking, and walking-type multi-point continuous jacking. Among these, the walking-type multi-point continuous jacking technology, developed from the wedge-type jacking construction of the Millau Viaduct in France, is currently the mainstream emerging jacking technology. This technology utilizes a jacking device integrating lifting, translation, and lateral adjustment functions to achieve multi-directional movement and attitude adjustment of the channel steel beam in the longitudinal, vertical, and transverse directions. By simultaneously pushing the structure through multiple support points, it effectively reduces uneven stress caused by structural deformation during bridge jacking, improving construction accuracy and stability.

[0003] Compared to traditional jacking technology, the walking jacking technology has significant advantages: the jacking force and friction are both internal forces of the jacking equipment, and the support piers basically do not bear horizontal loads; it is equipped with a lateral adjustment device, which can reduce lateral displacement during the jacking process and ensure stable construction; it has its own vertical jacks, which can adapt well to changes in the vertical alignment of the beam and is suitable for jacking construction needs of different bridge types and different alignment changes.

[0004] However, the jacking method currently used in China is intermittent jacking, which has a core technical defect: the friction coefficient of the beam changes greatly from static to dynamic, causing the beam to move forward in a "crawling state". That is, the beam moves forward suddenly after overcoming static friction under the push of the horizontal jack, and the beam returns to static when the jack ends. This causes repeated longitudinal forward and reverse displacement of the pier top, which poses a great threat to the structural safety of the pier body, especially flexible piers.

[0005] The frictional performance of the jacking mechanism is a core factor determining the displacement change of the jacked object, and its smoothness of movement and frictional durability directly ensure the structural safety of the jacking construction. However, current technology lacks a dedicated device capable of accurately testing the frictional performance of the jacking mechanism, resulting in two main problems: first, existing testing methods cannot replicate the actual operating environment of the jacking mechanism on the construction site, leading to significant discrepancies between the test results and actual working conditions; second, the load simulation range of the testing equipment is limited, making it difficult to cover the jacking testing needs of bridges of varying weights. This forces the frictional performance testing of the jacking mechanism to rely solely on on-site construction and commissioning, resulting in low testing efficiency and, due to the inability to proactively identify potential frictional performance issues, posing serious safety risks to bridge jacking construction.

[0006] Therefore, there is an urgent need to develop a device and method for testing the friction performance of jacking mechanisms that can maximize the reproduction of the construction site environment and broaden the load simulation range. This would enable comprehensive testing of the friction performance of jacking mechanisms during factory maintenance and repair, improve on-site construction and commissioning efficiency, reduce potential safety risks, and provide technical support for the safe application of various jacking processes, such as walking jacking. Summary of the Invention

[0007] To address the shortcomings of existing testing technologies, such as their inability to meet the testing requirements of walking-type jacking processes, difficulty in reproducing realistic construction environments, and limited load simulation range, this invention aims to provide a bidirectional reaction force jacking mechanism friction performance testing device and method. This device and method can broaden the load simulation range, adapt to the jacking testing requirements of large-span steel structure bridges of different weights, realize in-factory real-machine testing of the friction performance of the jacking mechanism, accurately detect the static and dynamic friction coefficients, smoothness of movement, and friction durability of the jacking mechanism, screen suitable friction-reducing components, improve on-site construction and commissioning efficiency, reduce construction safety risks, and provide technical assurance for the safe application of various jacking processes, including walking-type jacking.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A friction performance testing device for a bidirectional reaction force jacking mechanism includes a reaction frame, a jacking mechanism, a loading cylinder assembly, and a testing component;

[0010] The reaction frame is a truss structure, horizontally fixed in the test area. The reaction frame includes an upper structural beam and a lower structural beam that are vertically distributed and horizontally arranged.

[0011] The jacking mechanism is disposed between the upper structural beam and the lower structural beam. The jacking mechanism includes a jacking beam, an upper load cylinder assembly, and a lower load cylinder assembly. The upper load cylinder assembly is disposed between the upper structural beam and the jacking beam, and the lower load cylinder assembly is disposed between the lower structural beam and the jacking beam.

[0012] The upper load cylinder assembly and the lower load cylinder assembly have the same structure, each including two load cylinders arranged side by side and a connecting seat for connecting the two load cylinders. The connecting seat is slidably connected to the corresponding structural beam in the horizontal direction. A sliding friction pair is provided between the connecting seat and the corresponding structural beam. The sliding friction pair includes a first friction damping component and a second friction damping component. The first friction damping component is detachably installed on the side of the connecting seat facing the corresponding structural beam, and the second friction damping component is installed on the side of the structural beam facing the corresponding connecting seat. The first friction damping component and the second friction damping component are in close contact under the vertical load provided by the load cylinder.

[0013] The loading cylinder assembly includes an upper loading cylinder and a lower loading cylinder; one end of the upper loading cylinder is hinged to the upper structural beam, and its telescopic end is fixedly connected to the connecting seat of the upper load cylinder assembly; one end of the lower loading cylinder is hinged to the lower structural beam, and its telescopic end is fixedly connected to the connecting seat of the lower load cylinder assembly.

[0014] The detection components include a hydraulic pressure sensor, a displacement sensor, an industrial camera, and a super depth-of-field 3D microscope. The hydraulic pressure sensor is installed in the hydraulic system of each load cylinder and each loading cylinder to detect vertical load and horizontal traction force. The displacement sensor is installed on the side of the jacking mechanism to detect the horizontal displacement of the jacking mechanism. The industrial camera and the super depth-of-field 3D microscope are used to detect the surface condition of the sliding friction pair contact surface.

[0015] All components of the jacking mechanism and each loading cylinder are made from actual construction machine parts.

[0016] Preferably, the first friction-reducing component is fixed to the connecting seat by countersunk bolts, and the edge of the first friction-reducing component is provided with a limiting block.

[0017] Preferably, the second friction-reducing component is fixed to the corresponding structural beam by a combination of edge welding and central multi-point embedded welding.

[0018] Preferably, the first friction-reducing component is an MG (Modified General-purpose) plate or a stainless steel plate, wherein the MG plate is made of an engineering plastic alloy, including but not limited to MGE, MGA, and MGB.

[0019] Preferably, the second friction-reducing component is a stainless steel plate.

[0020] Preferably, the telescopic end of the load cylinder of the upper load cylinder assembly extends into a pre-set groove on the upper surface of the push beam; the telescopic end of the load cylinder of the lower load cylinder assembly extends into a pre-set groove on the lower surface of the push beam.

[0021] Preferably, the industrial camera is disposed on the side of the connector and is used to collect the macroscopic surface condition of the sliding friction pair contact surface; the ultra-depth-of-field three-dimensional microscope is used to detect the surface metallographic condition and microstructure of the sliding friction pair contact surface.

[0022] Preferably, the connecting seat includes a sleeve, which is sleeved on the outside of the cylinder barrel of the corresponding load cylinder and fixedly connected to the cylinder barrel.

[0023] Preferably, the upper loading cylinder is hinged to the upper structural beam via a hinge mechanism, and the lower loading cylinder is hinged to the lower structural beam via a hinge mechanism.

[0024] The hinge mechanism includes a hinge seat, a hinge shaft, and a connecting rod; the hinge shaft is fixed to the hinge seat, one end of the connecting rod is fixed to the bottom end of the cylinder of the loading cylinder, and the other end is rotatably engaged with the hinge shaft through a bearing.

[0025] In addition, the present invention also provides a method for testing the friction performance of a bidirectional reaction force jacking mechanism, which is implemented based on the above-mentioned bidirectional reaction force jacking mechanism friction performance testing device. The testing method includes the following steps:

[0026] S1. Prepare multiple sets of first friction-reducing components to be replaced, with any two sets of first friction-reducing components made of different materials; install one set of first friction-reducing components on the side of the upper and lower connecting seats of the jacking mechanism facing the corresponding structural beam.

[0027] S2. Assemble the jacking mechanism onto the reaction frame so that the first friction damping component on the upper connecting seat is in close contact with the second friction damping component on the upper structural beam, and the first friction damping component on the lower connecting seat is in close contact with the second friction damping component on the lower structural beam.

[0028] S3. Apply and gradually increase the vertical load to the jacking beam through the upper load cylinder assembly and the lower load cylinder assembly. Under each load level, gradually increase the horizontal traction force of the upper and lower loading cylinders on the jacking mechanism. Collect the horizontal traction force data in real time through the hydraulic pressure sensor and the sliding displacement data of the jacking mechanism in real time through the displacement sensor. Record the correspondence between traction force and sliding displacement under each load level.

[0029] S4. Replace the remaining first friction-reducing components one by one in sequence with the upper and lower connecting seats of the jacking mechanism. Repeat steps S2 and S3 after each replacement to obtain the vertical load, horizontal traction force and sliding displacement data of each group of first friction-reducing components when they are matched with the corresponding second friction-reducing components. Based on the collected vertical load and horizontal traction force, calculate the static friction coefficient and dynamic friction coefficient of the jacking mechanism when different first friction-reducing components are used.

[0030] S5. Based on the obtained static friction coefficient, dynamic friction coefficient and sliding displacement data, evaluate the smoothness of the jacking mechanism and select a set of first friction reducing components that are compatible with the jacking mechanism from multiple sets of first friction reducing components.

[0031] S6. Install the selected first friction-reducing component on the upper and lower connecting seats of the jacking mechanism facing the corresponding structural beam. Apply vertical loads to the jacking beam step by step and gradually increase them to the full vertical load through the upper and lower load cylinder assemblies. Apply the minimum horizontal traction force to make the jacking mechanism slide smoothly through the loading cylinder group, so that the jacking mechanism slides horizontally at a uniform speed to the end of the stroke. Then unload the vertical load and pull the jacking mechanism back to the initial position through the upper and lower loading cylinders. Apply the vertical load again and perform a cyclic test. After each set number of cycles, completely unload the vertical load, disassemble the upper and lower sliding friction pairs, cut the contact areas of each sliding friction pair to make test samples, and use an industrial camera and a super depth-of-field 3D microscope to perform macroscopic and microscopic morphology detection on the contact surfaces of the samples, respectively, and record the test data and the corresponding number of cycles. The maximum number of cycles in which there are no obvious microcracks and scratches on the contact surfaces of each sliding friction pair is used as the evaluation index of the friction durability of the jacking mechanism.

[0032] Compared with the prior art, the present invention has at least one of the following advantages or beneficial effects:

[0033] 1) This invention constructs a bidirectional reaction force jacking mechanism friction performance testing device, which adopts a symmetrical upper and lower real machine structure design. It can accurately simulate the key parameters and working conditions in the actual jacking construction process, providing an efficient and reliable experimental method for testing the friction performance of the jacking mechanism. Through this testing device, the static and dynamic friction coefficients, motion smoothness and friction durability of the jacking mechanism can be accurately measured, providing strong data support for the design optimization, performance evaluation and fault prediction of the jacking mechanism.

[0034] 2) This invention utilizes a symmetrical construction machine combined with a truss-type reaction frame design to achieve low-cost construction site environment restoration testing. It does not rely on on-site construction and debugging, and can complete the comprehensive testing of friction performance during the inspection and maintenance of the jacking mechanism. It also allows for the precise selection of the most suitable friction-reducing components, greatly improving the debugging efficiency of bridge jacking construction and standardizing the testing process of the friction performance of the jacking mechanism.

[0035] 3) In the process of testing the friction durability of the jacking mechanism, this invention adopts a detection method that combines an industrial camera and a super depth-of-field three-dimensional microscope to comprehensively analyze the surface morphology of the friction contact surface from both macroscopic and microscopic levels. Compared with the traditional visual inspection method, it can capture more details of contact surface damage and is more sensitive to the detection of the degradation of wear contact surface durability. Based on this, construction operations can be guided, and repairs and replacements can be carried out in a timely manner at the initial stage of friction contact surface damage, effectively avoiding potential safety risks during construction.

[0036] 4) The detection device and method of the present invention can optimize the friction performance of the jacking mechanism, enabling more accurate and efficient judgment of the real-time working status of the jacking mechanism in actual construction. This is beneficial for construction personnel to accurately control and judge the service life of the jacking mechanism, identify potential faults in equipment operation in advance, thereby effectively improving the stability of the jacking mechanism's operation, extending its service life, and reducing construction delays and economic losses caused by equipment failures. At the same time, the optimized jacking mechanism has higher operating efficiency, which can reduce energy consumption and indirectly reduce carbon emissions, resulting in significant economic and social benefits. Attached Figure Description

[0037] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings. The drawings are not drawn to scale; the emphasis is on illustrating the gist of the invention.

[0038] Figure 1 This is a front view of the friction performance testing device for the bidirectional reaction force jacking mechanism in an embodiment of the present invention;

[0039] Figure 2 This is a side view of the friction performance testing device of the bidirectional reaction force jacking mechanism in an embodiment of the present invention;

[0040] Figure 3 This is a flowchart of the friction performance testing method for the bidirectional reaction force jacking mechanism in an embodiment of the present invention;

[0041] Among them, 1. reaction frame; 11. upper structural beam; 12. lower structural beam; 2. jacking beam; 3. load cylinder; 4. connecting seat; 5. upper loading cylinder; 6. lower loading cylinder; 7. hinge mechanism; 8. sleeve. Detailed Implementation

[0042] Heavy-duty jacking equipment is a highly efficient and safe bridge construction tool, widely used in bridges constructed using the jacking construction technique. During construction using heavy-duty jacking equipment, the preset operations are mainly achieved through the contact surfaces of the sliding friction pairs within the equipment. The load-bearing capacity and frictional wear characteristics between the contact surfaces of these sliding friction pairs directly determine the overall working condition of the jacking equipment, affecting its overall efficiency and service life.

[0043] In engineering applications, it is necessary to design a corresponding friction and wear test bench based on the actual working principle of the contact surface of the sliding friction pair of the jacking equipment (which is the plane where the upper and lower friction-reducing components fit together), and use this device to test the friction and wear performance of the sliding friction pair. Static conditions refer to a state where there is no relative slippage, no speed change, and no external additional vibration or impact between the sliding friction pairs. At this time, it only bears a constant normal force (normal load) and static friction force. Dynamic conditions refer to a state where the jacking mechanism is in "motion or cyclic loading," that is, there is continuous or periodic relative slippage, speed change, acceleration, or external dynamic load (such as vibration, impact, alternating load) between the sliding friction pairs. At this time, the friction-reducing components must simultaneously bear the changing normal force, dynamic friction force, inertial force, and wear.

[0044] In large-scale engineering construction, jacking technology is widely used, and the friction performance of the jacking mechanism directly affects the safety, efficiency, and service life of the equipment. To accurately assess the friction performance of the jacking mechanism under complex working conditions and predict potential failures in advance, this invention designs a bidirectional reaction force jacking mechanism friction performance testing device and method to comprehensively evaluate the friction performance of the jacking mechanism and ensure its safety and reliability in bridge construction.

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but these are not intended to limit the scope of the invention.

[0046] Example 1:

[0047] like Figure 1 and 2 As shown, this embodiment provides a bidirectional reaction force jacking mechanism friction performance testing device, including a reaction frame 1, a jacking mechanism, a loading cylinder group and a testing component. The reaction frame 1, each component of the jacking mechanism and each cylinder of the loading cylinder group all adopt the actual construction machine components of a 400t walking jacking mechanism, ensuring that the test results are highly consistent with the actual construction conditions and improving the reliability and practicality of the test data.

[0048] The reaction frame 1 is a truss structure, horizontally fixed in the laboratory test area, providing a stable support foundation for the entire testing device. It is constructed of welded steel sections and specifically comprises three parallel, spaced rectangular frames fixedly connected by connecting beams, and upper structural beams 11 and lower structural beams 12, vertically distributed and horizontally arranged. Upper structural beams 11 connect to the inner top of the three rectangular frames, and lower structural beams 12 connect to the inner bottom of the three rectangular frames. The overall stiffness of this truss structure has been optimized to meet the testing requirements of a 400t full load, preventing deformation of the reaction frame 1 from affecting testing accuracy during the testing process.

[0049] The jacking mechanism is located between the upper structural beam 11 and the lower structural beam 12. It includes a jacking beam 2, an upper load cylinder assembly, and a lower load cylinder assembly. The upper load cylinder assembly is installed between the upper structural beam 11 and the jacking beam 2, and the lower load cylinder assembly is installed between the lower structural beam 12 and the jacking beam 2. The two work together to apply a stable vertical load to the lower jacking beam 2, simulating the vertical stress state of the jacking mechanism in actual construction.

[0050] The upper and lower load cylinder assemblies have identical structures, each consisting of two load cylinders 3 arranged side by side and a connecting seat 4 for connecting the two load cylinders 3. The telescopic ends of the load cylinders 3 in the upper load cylinder assembly extend into the pre-set grooves on the upper surface of the push beam 2, and the telescopic ends of the load cylinders 3 in the lower load cylinder assembly extend into the pre-set grooves on the lower surface of the push beam 2. Neither is fixedly connected—this avoids structural instability of the device under eccentric loading, facilitates the simulation of the pushing planes of different pushing mechanisms, and also ensures the convenience of disassembling and sampling the friction-reducing components.

[0051] The connecting seat 4 is slidably connected to the corresponding structural beam along the horizontal jacking direction. A sliding friction pair is provided between the connecting seat 4 and the corresponding structural beam. The sliding friction pair includes a first friction reducing component and a second friction reducing component. The first friction reducing component is detachably installed on the side of the connecting seat 4 facing the corresponding structural beam, and the second friction reducing component is fixedly installed on the side of the structural beam facing the corresponding connecting seat 4. Under the vertical load provided by the load cylinder 3, the first friction reducing component and the second friction reducing component are tightly fitted with a fitting gap of ≤0.05mm to ensure that the friction contact state is consistent with the actual construction.

[0052] Specifically, the first friction-reducing component is fixed to the connecting seat 4 by countersunk bolts, and its edge is equipped with a limiting block to prevent displacement of the first friction-reducing component during the testing process; the second friction-reducing component is fixed to the corresponding structural beam by a combination of edge welding and multi-point embedded welding at the center, improving connection stability and preventing detachment under stress. The first friction-reducing component can be made of MG plate or stainless steel plate, where MG plate is an engineering plastic alloy, including but not limited to a series of engineering plastic alloy materials such as MGE, MGA, and MGB. Among them, MGA is a high wear-resistant engineering plastic alloy, MGB is a heavy-duty engineering plastic alloy, and MGE is a low-friction engineering plastic alloy, all of which are well-known engineering plastic alloy materials in the field; the second friction-reducing component is uniformly made of stainless steel plate to ensure the stability and consistency of the friction contact surface.

[0053] The loading cylinder assembly includes an upper loading cylinder 5 and a lower loading cylinder 6, used to simulate the horizontal external force borne by the jacking mechanism in actual construction. The installation method is as follows: one end of the upper loading cylinder 5 is hinged to the upper structural beam 11 through a hinge mechanism 7, and the telescopic end is fixed to the connecting seat 4 of the upper load cylinder assembly through a flange; one end of the lower loading cylinder 6 is hinged to the lower structural beam 12 through a hinge mechanism 7, and the telescopic end is fixed to the connecting seat 4 of the lower load cylinder assembly through a flange.

[0054] The hinge mechanism 7 includes a hinge seat, a hinge shaft, and a connecting rod. The hinge seat consists of a base plate and two parallel side plates fixed to the base plate. The base plate is fixed to the corresponding structural beam. Both side plates are vertically arranged and have a first hinge hole at their top. The hinge shaft passes through the two first hinge holes along the width of the structural beam and is fixedly sleeved with them. One end of the connecting rod is fixed to the bottom end of the cylinder of the loading cylinder, and the other end is rotatably connected to the hinge shaft through a bearing. This structural design ensures that the loading cylinder can flexibly adapt to angular deviations during the jacking process, effectively avoiding jamming. Furthermore, the hinge shafts are all set perpendicular to the axis of the loading cylinder, further improving the rationality of force distribution.

[0055] The connecting seat 4 also includes a sleeve 8, which is fitted onto the outside of the cylinder of the load cylinder 3 and is fixedly connected to the cylinder of the load cylinder 3 by welding. This can significantly enhance the connection stability of the load cylinder assembly, prevent the load cylinder 3 from shaking or displacing during the testing process, and ensure the safety and accuracy of the testing process.

[0056] The detection components correspond one-to-one with the key parameters that need to be monitored during the synchronous jacking construction process, including the horizontal traction force of the mechanism, the vertical load, and the condition of the friction contact surface. It consists of various high-precision sensors and advanced detection equipment, specifically including hydraulic sensors, displacement sensors, industrial cameras, and ultra-depth-of-field 3D microscopes. The functions of each device are as follows:

[0057] Hydraulic pressure sensors: installed in the hydraulic systems of each load cylinder 3 and each loading cylinder, used to detect in real time the vertical load applied by the load cylinder 3 to the jacking beam 2, as well as the horizontal traction force of the loading cylinder on the jacking mechanism, providing accurate data support for evaluating the actual construction stress state of the jacking mechanism;

[0058] Displacement sensor: Installed on the side of the jacking mechanism, it is used to detect the horizontal displacement of the jacking mechanism in real time. By analyzing the displacement change pattern, it can be determined whether the jacking process is smooth and accurate.

[0059] Industrial camera: Fixed to the side of the connector 4, used to collect macroscopic surface conditions of the friction contact surface. Through image analysis, key information such as wear and lubrication status of the contact surface can be observed intuitively.

[0060] Ultra-depth-of-field 3D microscope: Set on the laboratory testing platform, with a magnification of 50-2000x, it is used to detect the metallographic state and microstructure of the contact surface, analyze the friction and wear mechanism at the microscopic level, and provide a scientific basis for optimizing the friction performance of the jacking mechanism.

[0061] In practical applications, by controlling the movement of the loading cylinder and the load cylinder 3, various working conditions during the jacking construction process can be simulated, including different load sizes, jacking speeds, and frictional contact states. The detection components collect various relevant data in real time and transmit them to the data analysis system. Through data analysis and processing, the frictional performance of the jacking mechanism under different working conditions can be accurately evaluated, such as changes in the friction coefficient, wear rate, and lubrication effect. Simultaneously, by combining key parameters such as jacking force, displacement, and time in actual construction, a correlation model between frictional performance and construction parameters can be established, providing strong technical support for the design optimization, performance improvement, and fault prediction of the jacking mechanism.

[0062] The bidirectional reaction force jacking mechanism friction performance testing device of this embodiment has significant advantages: First, it can accurately simulate the key parameters and working conditions of actual jacking construction, providing an efficient and reliable experimental means for friction performance testing. It can accurately measure key parameters such as horizontal traction force and vertical load, and monitor the surface condition and metallographic changes of the friction contact surface in real time, providing support for the design optimization, performance evaluation, and fault prediction of the jacking mechanism. Second, it avoids the high cost and high risk problems caused by directly testing the jacking mechanism in actual construction, effectively improving testing efficiency and safety. Third, the device can optimize the friction performance of the jacking mechanism, helping construction personnel to accurately judge the working status of the jacking mechanism, control the service life, identify potential cylinder operation faults in advance, improve the working stability of the jacking mechanism, extend its service life, and reduce construction delays and economic losses caused by equipment failures. At the same time, the optimized jacking mechanism has higher operating efficiency and lower energy consumption, indirectly reducing carbon emissions, and has significant economic and social benefits.

[0063] Example 2:

[0064] like Figure 3 As shown, this embodiment provides a method for testing the friction performance of a bidirectional reaction force jacking mechanism. Based on the bidirectional reaction force jacking mechanism friction performance testing device in Embodiment 1 above, this method has clear steps, strong operability, and can accurately evaluate the friction performance of the jacking mechanism. Specifically, it includes the following steps:

[0065] Step S1: Prepare multiple sets of first friction-reducing components to be replaced. Any two sets of first friction-reducing components should be made of different materials (for example, one set is made of MGE engineering plastic alloy, and the other set is made of MGA engineering plastic alloy. The material ratios of the two sets are different, so they are different materials). This ensures that the impact of different friction-reducing components on the friction performance of the jacking mechanism can be compared. Install one set of first friction-reducing components on the side of the upper and lower connecting seats of the jacking mechanism facing the corresponding structural beam. During installation, ensure that the components are firmly fixed and tightened in place with countersunk bolts to prevent them from falling off or shifting due to vibration during the testing process, thus ensuring the consistency of the testing benchmark.

[0066] Step S2: Assemble the jacking mechanism inside the reaction frame, and precisely adjust the horizontal and vertical positions of the jacking mechanism so that the first friction-reducing component on the upper connecting seat is in close contact with the second friction-reducing component on the upper structural beam, and the first friction-reducing component on the lower connecting seat is in close contact with the second friction-reducing component on the lower structural beam. Strictly control the contact gap to ≤0.05mm to ensure that the friction contact state is consistent with the actual construction conditions and to ensure the accuracy of friction performance testing.

[0067] Step S3: Apply vertical loads to the jacking beam in a steady, step-by-step manner using the upper and lower load cylinder assemblies, gradually increasing the load. Multiple load gradient levels are rationally defined (the load gradient can be set according to the actual construction load range of the 400t jacking mechanism). Under each load level, slowly and gradually increase the horizontal traction force of the upper and lower load cylinders on the jacking mechanism. Real-time data of the horizontal traction force is collected using hydraulic pressure sensors, and real-time data of the sliding displacement of the jacking mechanism is collected using displacement sensors. The correspondence between traction force and sliding displacement under each load level is accurately recorded, providing precise and complete data support for the subsequent calculation of static and dynamic friction coefficients.

[0068] Step S4: Replace the remaining sets of first friction-reducing components one by one synchronously with the upper and lower connecting seats of the jacking mechanism. During the replacement process, the load must be completely unloaded, the old friction-reducing components removed, and impurities cleaned from the contact surfaces of the connecting seats and structural beams before installing the new friction-reducing components. After each replacement, repeat steps S2 and S3 to ensure that the testing conditions of each set of friction-reducing components are completely consistent, avoiding differences in conditions affecting the comparability of test results. Obtain the vertical load, horizontal traction force, and sliding displacement data of each set of first friction-reducing components when used with the corresponding second friction-reducing components. Based on the collected vertical load and horizontal traction force, calculate the static friction coefficient and dynamic friction coefficient of the jacking mechanism using different first friction-reducing components. Taking a 400t jacking mechanism as an example, when MG plates are used as the friction-reducing material, the average static friction coefficient is 0.15, and the dynamic friction coefficient is approximately 0.12.

[0069] Step S5: Based on the obtained static friction coefficient, dynamic friction coefficient, and sliding displacement data, the system evaluates the smoothness of the jacking mechanism's movement. Specifically, it comprehensively evaluates the difference between the dynamic and static friction coefficients and the changing pattern of the sliding displacement data collected by the displacement sensor. The smaller the difference in friction coefficients and the higher the consistency of the displacement change rate, the better the smoothness of the jacking mechanism's movement. There will be no violent shaking during the jacking process, which can effectively avoid structural damage during construction. Based on the above evaluation results, the first friction-reducing component that is most suitable for the working conditions of the jacking mechanism is selected from multiple sets of first friction-reducing components.

[0070] Step S6: Securely install the selected first friction-reducing component onto the upper and lower connecting seats of the jacking mechanism on the side facing the corresponding structural beam. Apply vertical loads to the jacking beam step by step and smoothly through the upper and lower load cylinder assemblies, gradually increasing to the full vertical load (400t) to ensure uniform load application and avoid impact loads affecting the device and test results. Then, apply the minimum horizontal traction force to make the jacking mechanism slide smoothly through the loading cylinder group, controlling the jacking mechanism to slide horizontally at a uniform speed at the actual construction speed to the end of the stroke. After unloading the vertical load, slowly pull the jacking mechanism back to the initial position through the upper and lower loading cylinders, apply the vertical load again, and perform a cyclic test to simulate the reciprocating working state of the jacking mechanism in actual construction.

[0071] After each set number of cycles (10 cycles in this embodiment), the vertical load is completely unloaded, and the upper and lower sliding friction pairs are disassembled separately. The contact areas of each sliding friction pair are cut using specialized cutting equipment to create standard test specimens, ensuring the specimens are taken from the core friction contact area. The contact surfaces of the specimens are photographed using an industrial camera to perform macroscopic morphology inspection, observing macroscopic defects such as wear and scratches. The specimens are then examined using a super-depth-of-field 3D microscope (magnification 50-2000x) to analyze microscopic wear marks and metallographic changes on the contact surfaces. All test data and the corresponding number of cycles are recorded simultaneously. The maximum number of cycles with no obvious microcracks or scratches on the contact surfaces of each sliding friction pair is used as the evaluation index for the friction durability of the jacking mechanism. Taking a 400t jacking mechanism as an example, when solid MG plates are used as the friction-reducing material, the friction durability under full load is approximately 200 cycles.

[0072] It is not difficult to see that this embodiment is a method embodiment corresponding to the above-mentioned bidirectional reaction force jacking mechanism friction performance testing device. The two can be implemented in conjunction with each other to ensure that the structural design of the testing device and the operation steps of the testing method are highly compatible, thus ensuring the accuracy and reliability of the test data. The relevant technical details mentioned in the above device embodiment are still valid in this method embodiment, and will not be repeated here to reduce repetition; correspondingly, the relevant technical details mentioned in this method embodiment can also be applied to the above device embodiment to further improve the design logic of the device.

[0073] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments. Such variations do not affect the essence of the present invention and will not be elaborated upon here.

[0074] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A device for testing the friction performance of a bidirectional reaction-type jacking mechanism, characterized in that, Includes reaction frame, jacking mechanism, loading cylinder assembly and detection components; The reaction frame is a truss structure, horizontally fixed in the test area. The reaction frame includes an upper structural beam and a lower structural beam that are vertically distributed and horizontally arranged. The jacking mechanism is disposed between the upper structural beam and the lower structural beam. The jacking mechanism includes a jacking beam, an upper load cylinder assembly, and a lower load cylinder assembly. The upper load cylinder assembly is disposed between the upper structural beam and the jacking beam, and the lower load cylinder assembly is disposed between the lower structural beam and the jacking beam. The upper load cylinder assembly and the lower load cylinder assembly have the same structure, each including two load cylinders arranged side by side and a connecting seat for connecting the two load cylinders. The connecting seat is slidably connected to the corresponding structural beam in the horizontal direction. A sliding friction pair is provided between the connecting seat and the corresponding structural beam. The sliding friction pair includes a first friction damping component and a second friction damping component. The first friction damping component is detachably installed on the side of the connecting seat facing the corresponding structural beam, and the second friction damping component is installed on the side of the structural beam facing the corresponding connecting seat. The first friction damping component and the second friction damping component are in close contact under the vertical load provided by the load cylinder. The loading cylinder assembly includes an upper loading cylinder and a lower loading cylinder; one end of the upper loading cylinder is hinged to the upper structural beam, and its telescopic end is fixedly connected to the connecting seat of the upper load cylinder assembly; one end of the lower loading cylinder is hinged to the lower structural beam, and its telescopic end is fixedly connected to the connecting seat of the lower load cylinder assembly. The detection components include a hydraulic pressure sensor, a displacement sensor, an industrial camera, and a super depth-of-field 3D microscope. The hydraulic pressure sensor is installed in the hydraulic system of each load cylinder and each loading cylinder to detect vertical load and horizontal traction force. The displacement sensor is installed on the side of the jacking mechanism to detect the horizontal displacement of the jacking mechanism. The industrial camera and the super depth-of-field 3D microscope are used to detect the surface condition of the sliding friction pair contact surface. All components of the jacking mechanism and each loading cylinder are made from actual construction machine parts.

2. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The first friction-reducing component is fixed to the connecting seat by countersunk bolts, and the edge of the first friction-reducing component is provided with a limiting block.

3. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The second friction-reducing component is fixed to the corresponding structural beam by a combination of edge welding and central multi-point embedded welding.

4. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The first friction-reducing component is an MG plate or a stainless steel plate, and the MG plate is made of engineering plastic alloy, including but not limited to MGE, MGA, and MGB.

5. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The second friction-reducing component is a stainless steel plate.

6. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The telescopic end of the load cylinder of the upper load cylinder assembly extends into a pre-set groove on the upper surface of the push beam; the telescopic end of the load cylinder of the lower load cylinder assembly extends into a pre-set groove on the lower surface of the push beam.

7. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The industrial camera is mounted on the side of the connector and is used to collect the macroscopic surface condition of the sliding friction pair contact surface; the ultra-depth-of-field three-dimensional microscope is used to detect the surface metallographic condition and microstructure of the sliding friction pair contact surface.

8. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The connecting seat includes a sleeve, which is sleeved on the outside of the cylinder barrel of the corresponding load cylinder and fixedly connected to the cylinder barrel.

9. The friction performance testing device for the bidirectional reaction force jacking mechanism according to claim 1, characterized in that, The upper loading cylinder is hinged to the upper structural beam via a hinge mechanism, and the lower loading cylinder is hinged to the lower structural beam via a hinge mechanism. The hinge mechanism includes a hinge seat, a hinge shaft, and a connecting rod; the hinge shaft is fixed to the hinge seat, one end of the connecting rod is fixed to the bottom end of the cylinder of the loading cylinder, and the other end is rotatably engaged with the hinge shaft through a bearing.

10. A method for testing the friction performance of a bidirectional reaction force jacking mechanism, characterized in that, The friction performance testing device for the bidirectional reaction force jacking mechanism according to any one of claims 1 to 9 is used, and the testing method includes the following steps: S1. Prepare multiple sets of first friction-reducing components to be replaced, with any two sets of first friction-reducing components made of different materials; install one set of first friction-reducing components on the side of the upper and lower connecting seats of the jacking mechanism facing the corresponding structural beam. S2. Assemble the jacking mechanism onto the reaction frame so that the first friction damping component on the upper connecting seat is in close contact with the second friction damping component on the upper structural beam, and the first friction damping component on the lower connecting seat is in close contact with the second friction damping component on the lower structural beam. S3. Apply and gradually increase the vertical load to the jacking beam through the upper load cylinder assembly and the lower load cylinder assembly. Under each load level, gradually increase the horizontal traction force of the upper and lower loading cylinders on the jacking mechanism. Collect the horizontal traction force data in real time through the hydraulic pressure sensor and the sliding displacement data of the jacking mechanism in real time through the displacement sensor. Record the correspondence between traction force and sliding displacement under each load level. S4. Replace the remaining first friction-reducing components one by one in sequence with the upper and lower connecting seats of the jacking mechanism. Repeat steps S2 and S3 after each replacement to obtain the vertical load, horizontal traction force and sliding displacement data of each group of first friction-reducing components when they are matched with the corresponding second friction-reducing components. Based on the collected vertical load and horizontal traction force, calculate the static friction coefficient and dynamic friction coefficient of the jacking mechanism when different first friction-reducing components are used. S5. Based on the obtained static friction coefficient, dynamic friction coefficient and sliding displacement data, evaluate the smoothness of the jacking mechanism and select a set of first friction reducing components that are compatible with the jacking mechanism from multiple sets of first friction reducing components. S6. Install the selected first friction-reducing component on the upper and lower connecting seats of the jacking mechanism facing the corresponding structural beam. Apply vertical loads to the jacking beam step by step and gradually increase them to the full vertical load through the upper and lower load cylinder assemblies. Apply the minimum horizontal traction force to make the jacking mechanism slide smoothly through the loading cylinder group, so that the jacking mechanism slides horizontally at a uniform speed to the end of the stroke. Then unload the vertical load and pull the jacking mechanism back to the initial position through the upper and lower loading cylinders. Apply the vertical load again and perform a cyclic test. After each set number of cycles, completely unload the vertical load, disassemble the upper and lower sliding friction pairs, cut the contact areas of each sliding friction pair to make test samples, and use an industrial camera and a super depth-of-field 3D microscope to perform macroscopic and microscopic morphology detection on the contact surfaces of the samples, respectively, and record the test data and the corresponding number of cycles. The maximum number of cycles in which there are no obvious microcracks and scratches on the contact surfaces of each sliding friction pair is used as the evaluation index of the friction durability of the jacking mechanism.

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