A loading and unloading device and method for a true triaxial seepage test sealing ring

Abstract

The application discloses a kind of true triaxial seepage test sealing ring loading and unloading device and method, belong to geotechnical engineering test equipment technical field.The device includes device base and at least one sealing ring synchronous expansion support device.Device base is equipped with guide rail and locking structure.Sealing ring synchronous expansion support device includes expansion support device base, drive unit, transmission mechanism, synchronous linkage mechanism, jaw assembly and piston rod assembly.Drive unit moves by transmission mechanism to drive synchronous linkage mechanism, and then first jaw and second jaw are driven to expand or contract along radial direction synchronously.The method can efficiently and non-destructively complete sample loading and unloading through initial positioning, synchronous uniform expansion, sample loading, shrinkage wrapping and controllable separation.The application effectively solves the problems of low efficiency, easy damage to the sample and sealing ring, and difficult to guarantee the sealing effect of traditional manual operation, significantly improves the sample loading precision, operation safety and test reliability of true triaxial seepage test.

Description

Technical Field

[0001] This invention belongs to the technical field of geotechnical engineering testing equipment and is mainly applied to true triaxial seepage tests in the fields of rock mechanics, soil mechanics and geological engineering. It relates to a device for loading and unloading a sealing ring for a true triaxial seepage test, which aims to solve the technical problems of traditional manual loading and unloading methods, such as operational difficulties, low efficiency, easy damage to the sealing ring and sample, and difficulty in ensuring uniform sealing. Background Technology

[0002] With my country's economic development, large-scale projects involving deep-buried tunnels are increasing, and mining activities are penetrating deeper into the Earth's crust. However, in deep underground engineering, deep rocks, due to factors such as geological structure and crustal temperature gradients, exhibit a more complex anisotropic stress state than shallower rocks, and the difference between the three principal stresses increases with depth. Therefore, relevant research often requires true triaxial tests to simulate this stress state, and anisotropic loading, seepage, temperature coupling, and multiphase multifield tests are conducted to study the characteristics of deep rocks.

[0003] In modern true triaxial rock tests, test chambers and corresponding sealing devices are commonly used to achieve anisotropic loading, seepage, temperature coupling, and multiphase multifield experiments. However, existing test chambers and sealing devices suffer from complex sample loading and unloading processes. Based on this background and research needs, this invention aims to develop a sample loading and unloading device suitable for true triaxial tests. This device can automatically load and unload samples under true triaxial test loading conditions, thereby ensuring the accuracy of test results and preventing damage during sample unloading after failure.

[0004] Currently, true triaxial testing of rock materials often involves conditions such as anisotropic loading, seepage, temperature coupling, and multiphase multifield. True triaxial loading chambers are widely used in true triaxial testing of rock materials. Rubber sealing rings are commonly used to seal rock samples to achieve functions such as seepage and multifield coupling. During the test, the rock sample is placed inside the rubber sealing ring, and then the entire rubber sealing ring is placed in a metal frame, which is then placed in the true triaxial loading chamber.

[0005] This experimental method can effectively handle complex loading conditions; however, the nested multi-frame design makes sample loading and unloading extremely cumbersome, especially the steps of loading and unloading the sample from the rubber sealing ring. During loading, manual loading relies on repeated adjustments by the experimenter and is prone to misalignment between the sample and the rubber sealing ring, leading to eccentric forces during subsequent loading. During unloading, since the sample is already completely destroyed after loading, unloading can cause further damage, affecting subsequent failure mode analysis. Based on these technical problems, there is a need to develop a device and method that facilitates both loading and unloading to ensure the accuracy of experimental results. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for loading and unloading a sealing ring for a true triaxial flow test, which solves a series of technical problems in the prior art, such as low efficiency, difficult operation, easy damage to the sealing ring and sample, and difficulty in ensuring uniform force on the sealing ring, thus affecting the reliability of the test seal.

[0007] The first objective of this invention is to provide a device for loading and unloading a sealing ring for a true triaxial seepage test, comprising a device base and at least one sealing ring synchronous expansion device, wherein the device base is provided with a guide rail and a locking structure. The sealing ring synchronous expansion device includes an expansion device base, a drive unit, a transmission mechanism, a synchronous linkage mechanism, a gripper assembly, and a piston rod assembly; The expansion device base is set on the device base, the drive unit is set inside the expansion device base, and the transmission mechanism is connected to the output end of the drive unit; The gripper assembly includes a first gripper and a second gripper, both of which are mounted on the base of the expansion device in a radially sliding manner. The synchronous linkage mechanism is rigidly connected to the transmission mechanism, including a linkage base, a first link and a second link. It is hinged to the first gripper through the first link and to the second gripper through the second link. The end of the piston rod assembly is hinged to the second gripper, and the rod body of the piston rod assembly and the base of the expansion device form a sliding pair; The drive unit can drive the synchronous linkage mechanism to move through the transmission mechanism, and then drive the first gripper and the second gripper to perform radial expansion or contraction movements synchronously through the first link and the second link respectively.

[0008] The second objective of this invention is to provide a method for installing and removing a sealing ring in a true triaxial seepage test, comprising the following steps: S1 Initial Positioning: Place the rubber sealing ring to be installed on the outside of the gripper assembly; use the alignment and calibration assembly to control the synchronous expansion device of each sealing ring to move to the initial working position and lock it; S2 Synchronous Uniform Expansion: The control drive unit operates and, based on feedback from pressure and displacement sensors, drives the gripper assembly to expand radially, stretching the rubber sealing ring to a predetermined size or predetermined contact pressure. S3 Sample loading: Place the sample into the expanded rubber sealing ring; S4 Shrink Wrap: The control drive unit works in reverse, driving the gripper assembly to shrink radially, so that the rubber sealing ring wraps around the sample; S5 Unloading Preparation: Put the rubber sealing ring that has been wrapped around the sample back onto the outside of the gripper assembly; S6 Controllable Separation: The control drive unit operates, driving the gripper assembly to expand radially, creating a separation gap between the rubber sealing ring and the sample, and removing the sample.

[0009] This invention optimizes the system equipment and process flow, solving the defects of the existing system and achieving process optimization, with the following effects: (1) The loading and unloading device of the present invention, with the help of a multi-point synchronous expansion mechanism and an integrated laser alignment precision positioning system, can smoothly and accurately load the sample into the rubber sealing ring, ensuring that the sample and the sealing ring are completely aligned, effectively avoiding the misalignment problem that is easy to occur during manual installation. The precision of mechanical positioning ensures that the sample axis and the loading center are highly coincident, which not only ensures the sealing effect of the test, but also eliminates the test result deviation caused by eccentric loading, and improves the loading accuracy and data reliability of true triaxial test.

[0010] (2) Compared with the manual and repeated sample loading method, the automatic loading and unloading device of this invention is convenient to operate and has precise positioning. It can quickly complete the sample installation, greatly reduce the trouble of repeated loading caused by human error, and significantly improve the test efficiency. This device frees operators from tedious and repetitive physical labor, reduces the probability of errors caused by operator fatigue, ensures the consistency of the test operation process for different batches, and provides an efficient sample loading solution for large-scale and serialized true triaxial flow tests.

[0011] (3) After loading is completed, the rubber sealing ring is gently expanded by the automatic loading and unloading device, which allows the sample to be smoothly separated from the sealing ring without manual forced peeling. This avoids destructive operations such as hammering and prying, ensuring that even very fragile, loaded, and broken samples can be completely removed. This protective removal method preserves the original failure morphology and crack structure of the sample to the greatest extent, avoids secondary damage to the broken sample, and provides complete sample protection for subsequent sample failure mode analysis. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a top view of the expansion device in the loading and unloading device of the true triaxial seepage test sealing ring in this invention; Figure 2 This is a front view of the expansion device in the loading and unloading device of the true triaxial seepage test sealing ring in this invention; Figure 3 This is a top view of the overall mounting and dismounting device for the true triaxial seepage test sealing ring in this invention; Figure 4 This is a front view of the overall mounting and dismounting device for the true triaxial seepage test sealing ring in this invention; Figure 5 This is an overall side view of the mounting and dismounting device for the true triaxial seepage test sealing ring in this invention; Figure 6 This is a flowchart illustrating the loading and unloading method of the sealing ring for the true triaxial seepage test in this invention.

[0014] Explanation of reference numerals in the attached drawings: 1-Device base; 2-Sealing ring synchronous expansion device; 3-Expansion device base; 4-First gripper; 5-Second gripper; 6-Transmission mechanism; 7-Synchronous linkage mechanism; 8-Drive unit; 9-Piston rod assembly; 10 Slider. Detailed Implementation

[0015] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0016] To fully understand this invention, detailed steps and structures will be presented in the following description to illustrate the technical solution of this invention. A preferred embodiment of the invention is described in detail below. However, in addition to its application in mechanical testing of rocks and rock-like materials using true triaxial loading chambers, a device and method for loading and unloading sealing rings in true triaxial seepage tests is designed. The aim is to achieve efficient sample loading and unloading during true triaxial testing, improve testing efficiency, ensure uniform stress on the sample, and avoid damage to the sample after the test for analysis of failure modes, thereby improving the accuracy of the test.

[0017] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Example 1:

[0018] A device for loading and unloading a sealing ring in a true triaxial seepage test includes: a device base 1 and a sealing ring synchronous expansion device 2. The device base 1 is equipped with a guide rail and a locking structure. The sealing ring synchronous expansion device 2 includes an expansion device base 3, a drive unit 8, a transmission mechanism 6, a synchronous linkage mechanism 7, a gripper assembly, and a piston rod assembly 9.

[0019] The expansion device base 3 is mounted on the device base 1, and the drive unit 8 is mounted inside the expansion device base 3. The transmission mechanism 6 is connected to the output end of the drive unit 8. Specifically, the drive unit 8 can be a high-precision servo motor to provide precise and controllable rotational motion and torque output. The transmission mechanism 6 can be a drive shaft, which efficiently, smoothly, and reliably transmits the rotational motion output by the drive unit 8 and converts it into the motion form required by the synchronous linkage mechanism 7.

[0020] The gripper assembly includes a first gripper 4 and a second gripper 5. Both the first gripper 4 and the second gripper 5 are mounted on the expansion device base 3 in a radially sliding manner. The synchronous linkage mechanism 7 is rigidly connected to the transmission mechanism 6 and includes a linkage base, a first connecting rod, and a second connecting rod. The linkage base is rigidly connected to the output shaft or end of the transmission mechanism 6. One end of the first connecting rod is hinged to the linkage base, and the other end is hinged to the first gripper 4. One end of the second connecting rod is hinged to the linkage base, and the other end is hinged to the second gripper 5. The end of the piston rod assembly 9 is hinged to the second gripper 5, and the rod body of the piston rod assembly 9 and the expansion device base 3 form a precision sliding pair. The key functions of the piston rod assembly 9 are as follows: on the one hand, it provides a strong radial motion guide constraint for the second gripper 5, ensuring that its motion trajectory is strictly linear and preventing jamming or uneven wear caused by lateral forces; on the other hand, it forms a composite force-bearing structure with the connecting rod mechanism, which can effectively share the huge radial reaction force generated by the gripper when expanding the sealing ring, significantly reducing the bending stress borne by the connecting rod, thereby improving the rigidity and durability of the entire force transmission chain and avoiding the decrease in synchronization accuracy caused by connecting rod deformation under long-term use.

[0021] During operation, the drive unit 8 starts, driving the synchronous linkage mechanism 7 to move via the transmission mechanism 6. The linkage base of the synchronous linkage mechanism 7 rotates with the output shaft of the transmission mechanism 6, and then, through the first and second connecting rods, converts the single input motion of the linkage base into synchronous reverse radial motion of the first gripper 4 and the second gripper 5. This ensures that, regardless of expansion or contraction, the two first grippers 4 or second grippers 5 always move symmetrically relative to the center, thereby applying a uniform, concentric radial force to the rubber sealing ring fitted outside the gripper assembly. This uniform expansion method effectively avoids local stress concentration in the sealing ring, preventing irreversible local tensile damage or tearing during loading and unloading, ensuring the integrity of the sealing ring and its sealing performance in subsequent tests. At the same time, the synchronous motion also allows the sealing ring to maintain a perfectly circular expansion shape, creating ideal conditions for the smooth and centered insertion of the sample.

[0022] In one specific embodiment, the transmission mechanism 6 is a reduction gear set or a worm gear, which can effectively reduce the output speed while increasing the output torque. Even when facing thick-walled or high-modulus rubber seals that require a large radial force to expand, the device can provide sufficient and stable expansion force, avoiding the stalling, overload, or insufficient force problems that may occur when the motor is directly driven, ensuring stable operation under high load conditions. The precision reduction gear set or worm gear pair also features low backlash and high rigidity. Low backlash means that the backlash error of the transmission chain is small when the motor switches between forward and reverse directions, thus ensuring that the gripper assembly can quickly respond to commands, move precisely and synchronously, and has high repeatability during expansion and contraction. High rigidity ensures that the transmission system has minimal deformation when subjected to the reaction force from the seal, further ensuring the accuracy of motion transmission and the stability of the gripper position, which is crucial for maintaining the uniformity and dimensional consistency of the seal expansion. When the transmission mechanism 6 uses a worm gear pair, its inherent reverse self-locking characteristic can also be utilized. When the motor stops supplying power, the self-locking effect can reliably lock the position of the gripper, preventing it from moving on its own due to the elastic restoring force of the sealing ring or accidental external force. This provides an important safety guarantee for the loading and unloading process, ensuring that even if the power is cut off, the position of the sealing ring or the sample will not change unexpectedly when it is clamped or expanded, thus preventing safety accidents and accidental damage to the sealing ring or the sample.

[0023] In one specific embodiment, three sealing ring synchronous expansion devices 2 are installed on the device base 1. One of the three sealing ring synchronous expansion devices 2 is fixedly installed on the top surface of the device base 1, while the other two are perpendicular to this sealing ring synchronous expansion device 2 and can move bidirectionally along a high-precision linear guide rail on the device base 1 via a slider 10, and are fixed by locking structures such as butterfly bolts or quick-locking handles. The movable design expands the applicability of the device; by simply adjusting the positions of the two moving devices, different specifications of rubber sealing rings can be quickly and accurately matched, achieving multi-purpose functionality and avoiding the cumbersome and costly process of equipping multiple sets of special tools for samples of different sizes. The guide rail and locking structure ensure the accuracy and rigidity of the positioning after movement, ensuring that the expansion point is firmly and reliably positioned during expansion operations, preventing slippage and thus guaranteeing the coaxiality and stability of the expansion force.

[0024] In one specific embodiment, the linkage base of the synchronous linkage mechanism 7 and the end of the transmission mechanism 6 are rigidly connected via a keyway connection or a flange bolt connection, eliminating transmission backlash and ensuring the immediacy and lag-free nature of power transmission. One end of both the first and second connecting rods is hinged to corresponding lugs on the linkage base via pins, while the other end is similarly hinged to hinge holes on the first and second grippers 4 and 5 via pins. This hinge pair design efficiently and with low friction converts the input motion of the linkage base into the linear motion of the grippers. It achieves motion transmission and conversion, ensuring a definite proportional relationship between the gripper assembly displacement and the motor output, facilitating precise displacement control. Multiple hinge points absorb minor errors that may exist during manufacturing and assembly, making the mechanism move more smoothly and reducing the risk of jamming. The combination of rigid connection and hinges ensures transmission efficiency while avoiding over-constraint, allowing the mechanism to automatically self-align through minor hinge rotations when subjected to radial loads, optimizing force distribution.

[0025] In one specific embodiment, the base 3 of the expansion device is provided with a guide portion, and the gripper assembly is provided with a sliding portion that cooperates with the guide portion, so that the first gripper 4 and the second gripper 5 can slide radially. The guide portion can be a linear guide rail or a guide groove, and the sliding portion is a matching guide block. This sliding pair provides high-precision, low-resistance guidance for the radial movement of the grippers, restricts the degree of freedom of movement of the grippers, and makes them only able to move in a predetermined radial straight line, eliminating the possibility of lateral swaying or rotation. This ensures the accuracy of the movement trajectory of the gripper assembly during the expansion and contraction process, thereby ensuring that the expansion force applied to the rubber sealing ring is always in the radial direction, avoiding the torsion or scratch damage to the sealing ring caused by the tangential component force. It improves the rigidity and movement smoothness of the entire actuator. Even when subjected to a large radial reaction force, the gripper assembly can move smoothly without crawling or shaking, laying the foundation for achieving smooth and controllable deformation of the sealing ring.

[0026] In one specific embodiment, the gripper assembly also includes replaceable chucks, which can be detachably mounted on the ends of the first gripper 4 and the second gripper 5 via hexagonal socket head cap screws or quick-release pins. The inner surface of the replaceable chucks is machined with fine, arc-shaped anti-slip textures or coated with a high-friction coefficient elastomer, increasing the static friction between the chucks and the inner wall of the rubber sealing ring. This prevents relative sliding between the sealing ring and the chucks during expansion, ensuring reliable transmission of the expansion action. Simultaneously, a series of replaceable chuck specifications with different radii of curvature are available, each specification having an inner arc surface curvature optimally suited to rubber sealing rings within a specific inner diameter range. Users can adapt the same device to sealing rings of various sizes simply by changing the chucks, reducing equipment costs and operational complexity. The adaptable arc-shaped chucks increase the contact area with the sealing ring, optimizing the expansion force from point or line contact to surface contact, reducing pressure on the contact surface, and preventing excessive local stress from damaging the rubber material. This is particularly effective in protecting thin-walled or highly elastic sealing rings. Furthermore, since the chuck is a consumable part or a component that needs to be adapted to different working conditions, it can be replaced separately, reducing maintenance costs.

[0027] In one specific embodiment, a displacement sensor for monitoring the radial displacement of the second gripper 5 is integrated on the piston rod assembly 9. This displacement sensor can be a magnetostrictive displacement sensor, a grating ruler, or a high-precision linear potentiometer. Its signal output is connected to the device's control module in real time. The control module can drive the motor to run according to a preset displacement value until the actual displacement fed back by the displacement sensor reaches the set value, thereby precisely controlling the expansion diameter of the sealing ring to meet the loading and unloading requirements of samples of different sizes. This is more accurate and reliable than simple time or number of rotations control. Real-time displacement data can also be used to monitor whether the loading and unloading process is normal, and the system can record the displacement curve for each operation, providing data support for analyzing the deformation characteristics of the sealing ring and optimizing loading and unloading process parameters.

[0028] In one specific embodiment, the guide portion is a dovetail-shaped guide groove formed on the top of the base 3 of the expansion device. The sliding portion is a dovetail-shaped slider formed on the bottom of the gripper assembly, which mates with the dovetail-shaped guide groove. The dovetail-shaped guide structure features automatic centering, strong load-bearing capacity, and excellent anti-overturning moment. Limit blocks are provided at both ends of the dovetail-shaped guide groove, which provide mechanical hard limiting when the mechanism moves to its limit position, preventing the dovetail-shaped slider from rushing out of the groove due to accidents or control failures, causing damage to the mechanism or safety accidents, thus increasing the safety of the equipment. Furthermore, gap adjustment shims of different thicknesses are provided between the mating sides of the dovetail-shaped guide groove and the dovetail-shaped slider. After long-term use, wear will occur in the sliding pair, leading to increased gap and affecting motion accuracy. By replacing or adding / removing shims, the mating gap between the slider and the groove can be precisely adjusted, restoring their tight fit, ensuring smooth and wobbly movement, thereby extending the service life of the device and maintaining long-term accuracy. Furthermore, during initial assembly, shims can be adjusted to compensate for machining errors, ensuring optimal fit between all moving parts, reducing the precision requirements for part machining, and thus controlling manufacturing costs.

[0029] In one specific embodiment, the loading and unloading device further includes a pressure feedback module. The pressure feedback module includes a miniature thin-film pressure sensor embedded in the surface of the replaceable gripper, which is connected to the control module via flexible wiring or wireless transmission. During the expansion of the sealing ring, the control target can switch from displacement mode to pressure mode. The system uses a set target contact pressure as the control target, driving the gripper to expand until the pressure sensor feedback value reaches the set value. The pressure mode can adapt to sealing rings with different stiffness and wear conditions, ensuring that the radial force applied during each loading and unloading is optimal and consistent, fundamentally avoiding the risk of plastic damage to the sealing ring due to overpressure or the risk of the sealing ring falling off due to insufficient pressure. It also enables real-time monitoring of pressure data. If abnormal pressure fluctuations occur during expansion or contraction, such as a sudden increase (which may indicate foreign object obstruction) or a sudden decrease (which may indicate sealing ring slippage), the control system can immediately trigger an emergency stop to protect the device and the workpiece.

[0030] In one specific embodiment, the loading and unloading device further includes an alignment calibration component. The alignment calibration component includes a laser alignment device mounted on the device base 1 and alignment marks, which can be crosshairs, located on the side of each expansion device base 3. The laser alignment device emits a visible crosshair laser line. Before loading and unloading, the operator manually or electrically fine-tunes the movable sealing ring of the expansion device 2 to ensure that the center of the laser crosshair coincides with the center of the alignment mark on each base. This ensures that the gripper tips of the expansion device 2 are on the same circumference centered on the sample axis and symmetrically distributed. This precise alignment is a prerequisite for subsequent uniform expansion, avoiding twisting or uneven stress on the sealing ring caused by initial alignment deviations. Compared to traditional visual inspection or caliper measurement for alignment, laser alignment is intuitive, accurate, and efficient, shortening preparation time, reducing reliance on operator experience, and improving the standardization and repeatability of the entire process.

[0031] Example 2:

[0032] The present invention also provides a method for loading and unloading a sealing ring for a true triaxial seepage test, using the loading and unloading device described in the above embodiments, including the following steps: S1 Initial Positioning: Place the rubber sealing ring to be installed on the outside of the gripper assembly. Activate the laser alignment device and observe the position of the laser line on the alignment mark on the base 3 of the expansion device. Fine-tune the movable sealing ring on the base 1 of the device to synchronously expand the device 2 until the alignment mark is aligned with the laser line. Then tighten the locking structure to ensure that the entire system is aligned with the theoretical central axis of the sample to be installed, laying the geometric foundation for uniform expansion.

[0033] S2 Synchronous Uniform Expansion: Select the operating mode and set the target value on the control panel. Start drive unit 8. The control system, based on real-time feedback from displacement and / or pressure sensors, controls the motor to drive all gripper assemblies to expand radially synchronously and smoothly. In displacement mode, the sealing ring is expanded to just the diameter allowing the sample to pass through. In pressure mode, the sealing ring is expanded to reach a preset safe contact pressure with the gripper. The core effect of this step is to achieve controllable, uniform, and damage-free elastic deformation of the rubber sealing ring, replacing the dangerous and unstable manual prying operation.

[0034] S3 Sample Insertion: Place the sample along the centered axis into the center of the evenly expanded rubber seal. Due to the uniform expansion and precise dimensions, the sample can fall smoothly without any risk of jamming or scratching the inner wall of the seal.

[0035] S4 Shrink Wrap: The control drive unit 8 operates in reverse, driving the gripper assembly to shrink radially at a controllable speed. Under its own elastic restoring force and guided by the grippers, the sealing ring wraps evenly and tightly around the outer surface of the sample. Pressure feedback ensures that the sealing ring applies an appropriate and uniform radial wrapping force to the sample upon termination of shrinkage, guaranteeing initial sealing while avoiding disturbance or damage to the sample structure that might result from overly tight wrapping.

[0036] S5 Unloading Preparation: When the specimen needs to be removed after the seepage test, the rubber sealing ring that has been wrapped around the specimen is put back onto the outside of the clamp assembly which is in a contracted state.

[0037] S6 Controllable Separation: The control drive unit 8 operates, driving the gripper assembly to expand radially again. The expansion force acts on the inner wall of the sealing ring through the gripper, gradually creating a controllable and uniform separation gap between it and the outer surface of the sample. Once the gap is sufficient, the sample can be easily and smoothly removed axially from the sealing ring. Throughout the process, there is no hard friction between the sample and the sealing ring, completely avoiding physical damage to the sample and sealing ring caused by traditional hammering or prying methods. After the sample is removed, the sealing ring returns to its original shape after the gripper retracts and resets, ready for the next use.

[0038] 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, nor is it limited to the mounting and dismounting device and method for the sealing ring in a true triaxial seepage test. Equipment and structures not described in detail herein should be understood as being implemented in a manner common to the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, 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, still fall within the protection scope of the present invention.

Claims

1. A device for loading and unloading a sealing ring capable of performing a true triaxial seepage test, characterized in that, It includes a device base and at least one sealing ring synchronous expansion device, and the device base is provided with a guide rail and a locking structure; The sealing ring synchronous expansion device includes an expansion device base, a drive unit, a transmission mechanism, a synchronous linkage mechanism, a gripper assembly, and a piston rod assembly; The expansion device base is set on the device base, the drive unit is set inside the expansion device base, and the transmission mechanism is connected to the output end of the drive unit; The gripper assembly includes a first gripper and a second gripper, both of which are mounted on the base of the expansion device in a radially sliding manner. The synchronous linkage mechanism is rigidly connected to the transmission mechanism, including a linkage base, a first link and a second link. It is hinged to the first gripper through the first link and to the second gripper through the second link. The end of the piston rod assembly is hinged to the second gripper, and the rod body of the piston rod assembly and the base of the expansion device form a sliding pair; The drive unit can drive the synchronous linkage mechanism to move through the transmission mechanism, and then drive the first gripper and the second gripper to perform radial expansion or contraction movements synchronously through the first link and the second link respectively.

2. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 1, characterized in that: Three sealing ring synchronous expansion devices are installed on the device base. The three sealing ring synchronous expansion devices are arranged along the device base to adapt to rubber sealing rings of different sizes. Among the three synchronous expansion devices for sealing rings, one is fixedly installed on the top surface of the device base, while the other two are perpendicular to this synchronous expansion device for sealing rings and can move bidirectionally along the preset guide rails on the device base and be fixed by the locking structure.

3. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 1, characterized in that: The linkage base of the synchronous linkage mechanism is rigidly connected to the transmission mechanism; one end of the first link and the second link are both hinged to the linkage base, and the other end is respectively hinged to the first gripper and the second gripper.

4. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 1, characterized in that: The base of the expansion device is provided with a guide part, and the gripper assembly is provided with a sliding part that cooperates with the guide part, so that the first gripper and the second gripper can slide radially.

5. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 1, characterized in that: The gripper assembly also includes a replaceable chuck, which is detachably mounted at the ends of the first and second grippers; The replaceable collet has an arc-shaped anti-slip texture on its surface and is available in different arc sizes to accommodate rubber sealing rings with different inner diameters.

6. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 5, characterized in that: The piston rod assembly is equipped with a displacement sensor for monitoring the radial displacement of the second gripper.

7. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 4, characterized in that: The guide section is a dovetail-shaped guide groove formed on the top of the base of the expansion device; The sliding part is a dovetail-shaped slider formed at the bottom of the gripper assembly and that mates with the dovetail-shaped guide groove; The end of the dovetail guide groove is provided with a limiting block to prevent the dovetail slider from sliding excessively and disengaging; a gap adjustment shim is provided between the dovetail guide groove and the dovetail slider.

8. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 6, characterized in that: It also includes a pressure feedback module, which includes a pressure sensor disposed on the surface of the replaceable chuck, and the pressure sensor is connected to the control module.

9. The device for loading and unloading a sealing ring capable of performing a true triaxial seepage test according to claim 8, characterized in that: It also includes an alignment calibration component, which includes a laser alignment device mounted on the device base and an alignment mark mounted on the expansion device base.

10. A method for loading and unloading a sealing ring for a true triaxial seepage test, comprising the loading and unloading device as described in claim 9, characterized in that, Includes the following steps: S1 Initial Positioning: Place the rubber sealing ring to be installed on the outside of the gripper assembly; use the alignment and calibration assembly to control the synchronous expansion device of each sealing ring to move to the initial working position and lock it; S2 Synchronous Uniform Expansion: The control drive unit operates and, based on feedback from pressure and displacement sensors, drives the gripper assembly to expand radially, stretching the rubber sealing ring to a predetermined size or predetermined contact pressure. S3 Sample loading: Place the sample into the expanded rubber sealing ring; S4 Shrink Wrap: The control drive unit works in reverse, driving the gripper assembly to shrink radially, so that the rubber sealing ring wraps around the sample; S5 Unloading Preparation: Put the rubber sealing ring that has been wrapped around the sample back onto the outside of the gripper assembly; S6 Controllable Separation: The control drive unit operates, driving the gripper assembly to expand radially, creating a separation gap between the rubber sealing ring and the sample, and removing the sample.

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