Elbow clamping tool, elbow self-reinforcing device and method

Abstract

This application relates to the field of ultra-high pressure pipeline handling and testing, specifically an elbow clamping fixture, an elbow self-reinforcing device, and a method. The elbow clamping fixture includes a support frame, a port clamping assembly for clamping the port portion of the elbow under test to define its position, and a hydraulic compensation mechanism mounted on the support frame with a force-applying end acting on the port clamping assembly. The hydraulic compensation mechanism dynamically adjusts the clamping force applied through the force-applying end based on changes in the internal medium pressure of the elbow under test, compensating for port deformation caused by increased internal medium pressure. This application's hydraulic compensation mechanism dynamically adjusts the applied clamping force based on changes in the internal medium pressure of the elbow under test, actively counteracting port deformation caused by increased internal pressure, achieving dynamic active compensation clamping, improving sealing reliability under ultra-high pressure conditions, ensuring the stability of test boundary conditions, and thus improving the accuracy of data acquisition.

Description

Technical Field

[0001] This application relates to the field of ultra-high pressure pipeline processing and testing, and to a elbow clamping fixture, an elbow self-reinforcing device and method. Background Technology

[0002] In the manufacturing and maintenance of equipment such as ultra-high pressure tubular reactors, elbow components typically require self-reinforcing treatment. This involves injecting high-pressure media into the elbow to induce plastic deformation of its inner wall, generating beneficial residual stress. Existing elbow fixing and sealing solutions mainly include bolt pre-tightening fixing based on rigid flanges. In rigid fixing solutions, the enormous pre-tightening force of the bolts forcibly restricts port displacement. However, when the internal media pressure rises to ultra-high pressure conditions (e.g., hundreds of megapascals), significant circumferential and axial stresses are generated on the elbow wall, leading to irreversible radial expansion (commonly known as the "bellows effect") and axial elongation at the elbow port.

[0003] For the aforementioned existing technical solutions, the geometric deformation caused by internal pressure leads to a decrease in the sealing specific pressure of the sealing component, thereby causing leakage of ultra-high pressure media; or, applying excessive static preload to resist deformation may cause brittle fracture or excessive elastic deformation of the flange or elbow port under high pressure. In addition, since existing technologies mostly use static constraints, they cannot adjust the clamping state according to real-time pressure changes during the dynamic processes of pressurization, pressure holding, and pressure release, resulting in the boundary conditions actually borne by the elbow not matching the theoretical model, affecting the accuracy of the self-reinforcing effect assessment. Summary of the Invention

[0004] To address the technical problem mentioned in the background art, where increased internal medium pressure leads to deformation of the elbow port, resulting in sealing failure and test data deviation, this application provides an elbow clamping fixture, comprising: Supporting framework; A port clamping assembly is used to clamp the port portion of the elbow under test in order to define the port position of the elbow under test. A hydraulic compensation mechanism is mounted on the support frame and has a force-applying end that acts on the port clamping assembly; The hydraulic compensation mechanism is configured to dynamically adjust the clamping force applied through the force-applying end according to the change in the internal medium pressure of the elbow under test, so as to compensate for the port deformation of the elbow under test caused by the increase in internal medium pressure.

[0005] By setting up a support frame as the basic load-bearing structure and configuring a port clamping assembly specifically for defining the position of the elbow port, combined with a hydraulic compensation mechanism installed on the support frame, this solution establishes a dynamic adjustment mechanism. The hydraulic compensation mechanism can sense changes in the internal medium pressure of the elbow under test in real time and dynamically adjust the applied clamping force accordingly, actively counteracting the port deformation caused by the increase in internal pressure. This shift from static rigid clamping to dynamic active compensation clamping improves the sealing reliability under ultra-high pressure conditions, ensures the stability of test boundary conditions, and thus improves the accuracy of data acquisition.

[0006] Optionally, the hydraulic compensation mechanism includes a hydraulic cylinder, which is connected to a test pipeline that provides medium pressure to the elbow under test. The internal oil pressure of the hydraulic cylinder is balanced with the internal medium pressure of the elbow under test, so that the force-applying end applies a clamping force that matches the internal medium pressure of the elbow under test.

[0007] By employing a hydraulic cylinder as the actuator and directly connecting the internal oil circuit of the cylinder to the test pipeline, the principle of fluid statics is used to ensure that the oil pressure inside the cylinder is always equal to the pressure of the medium inside the elbow under test, thus achieving automatic follow-up compensation in a purely mechanical hydraulic manner. This solution achieves force balance without the need for complex external control algorithms, resulting in a fast system response, high reliability, and reduced dependence on and cost of electrical control systems.

[0008] Optionally, the elbow clamping fixture also includes: A pressure detection unit is connected to the inside of the elbow to be tested, and is used to obtain the pressure of the medium inside the elbow to be tested; The controller is electrically connected to the pressure detection unit and the hydraulic compensation mechanism, and is used to control the output pressure of the hydraulic compensation mechanism to match the pressure of the medium inside the elbow to be tested.

[0009] By adding a pressure detection unit to directly acquire real-time pressure data and introducing a controller to construct an electronic control closed loop, the hydraulic compensation mechanism can output the corresponding target pressure after processing the pressure signal through an algorithm. This solution provides a flexible control strategy, allowing the setting of a nonlinear pressure-clamping force relationship according to experimental requirements, and is suitable for test scenarios with extremely high compensation accuracy requirements.

[0010] Optionally, the elbow clamping fixture also includes: A strain detection unit is disposed on the outer wall of the elbow port to be tested or in the vicinity of the port clamping assembly, for acquiring strain data at the elbow port to be tested. The controller is electrically connected to the strain detection unit and the hydraulic compensation mechanism. It is used to receive the strain data and generate a pressure boosting command when the strain data exceeds a preset threshold, and send it to the hydraulic compensation mechanism to increase the output pressure of the hydraulic compensation mechanism.

[0011] By setting up a strain detection unit to directly acquire deformation data at the elbow port and using the actual deformation state as feedback, the output pressure is automatically increased when the detected strain data exceeds a preset safety threshold. This solution achieves deformation-based feedback control, which can more directly prevent sealing surface separation and further improve system safety.

[0012] Optionally, the port clamping assembly includes at least two clamping members arranged opposite each other, and the hydraulic compensation mechanism includes at least two hydraulic actuators arranged opposite each other. The force-applying ends of the two hydraulic actuators are respectively connected to the two clamping members, and are used to drive the two clamping members to open or tighten relative to each other to apply a clamping force to the port of the elbow to be tested.

[0013] By designing the port clamping assembly as at least two opposing clamping elements and correspondingly setting hydraulic actuators to establish a one-to-one driving relationship, bidirectional movement of driving the two clamping elements to open or close relative to each other is achieved. This structure provides a flexible clamping execution method, can adapt to elbows of different sizes, and achieve uniform wrap-around clamping, ensuring uniform distribution of clamping force.

[0014] Optionally, the clamping member and the hydraulic actuator are arranged radially along the port of the elbow to be tested; At least two of the clamping members abut against opposite sides of the same port of the elbow under test to apply radial clamping force to the port of the elbow under test; or, at least two of the clamping members abut against the outer sides of both ends of the elbow under test to apply radial clamping force to both ends of the elbow under test.

[0015] By arranging the clamping components and hydraulic actuators along the radial direction of the elbow port and applying radial clamping forces to the opposite sides of a single port or the outer sides of both ports, the radial plastic deformation of the elbow port under ultra-high pressure is effectively suppressed. This solution specifically compensates for the "flare" effect, protecting the roundness of the port and preventing seal failure due to radial expansion.

[0016] Optionally, the port clamping assembly further includes two sealing joints, which are used to connect the first and last ports of the two elbows under test in series so that the inner cavities of the two elbows under test are interconnected to form a closed pressurized circuit. The two clamping members are located on the outer sides of the two ends of the elbow to be tested, and each clamping member abuts against the sidewall of the two ends of the elbow to be tested and the sealing joint.

[0017] By adding a sealing joint to the two elbows in a series test scenario, a closed pressurized circuit is formed by connecting the two elbows end-to-end. Clamping components located on the outer sides of both ends simultaneously abut against the port sidewalls of both elbows and the intermediate sealing joint, thus solving the problem of intermediate seal stability in series testing of double elbows. This solution applies a pre-tightening force to the entire assembly through the outer clamping components, enhancing system rigidity and ensuring the overall stability of the series structure under high pressure. Furthermore, it achieves self-reinforcement of both elbows in one step, improving work efficiency.

[0018] Optionally, the sealing joint includes: The support portion is flush with the side wall of the port of the elbow to be tested; The shaft core sealing parts are disposed on opposite sides of the support part. The two shaft core sealing parts are respectively used to extend into the ports of the two elbows to be tested to seal the ports of the elbows to be tested. The shaft core sealing parts have through holes that penetrate the support part and are used to connect the inner cavities of the two elbows to be tested.

[0019] By designing a specialized sealing joint with a support section and a core seal section, where the support section is flush with the side wall of the elbow port as a force-bearing reference surface, and the core seal section extends into the port to achieve a seal and has a through hole connecting the inner cavity, this structure can effectively resist the erosion and leakage of high-pressure media. At the same time, the support section provides a reliable force-bearing surface for external clamping, improving the pressure resistance of the tandem sealing structure.

[0020] Optionally, the clamping member and the hydraulic actuator are arranged along the axial direction of the port of the elbow to be tested; At least one of the clamping members abuts against the port side of the elbow to be tested, and at least one of the clamping members abuts against the outer side of the elbow to be tested on the side away from the port, so as to apply an axial clamping force to the port of the elbow to be tested.

[0021] By arranging the clamping components and hydraulic actuators along the axial direction of the elbow port and employing an asymmetrical contact method (one end abutting the port side, and the other end abutting the outer side of the bend), an axial clamping force is applied to the elbow. This solution directly counteracts the enormous axial thrust under ultra-high pressure, preventing the port sealing surface from separating due to axial displacement, and is a key means of solving the axial leakage problem.

[0022] Optionally, an adaptive ball joint assembly is provided between the force-applying end of the hydraulic actuator and the clamping member. The adaptive ball joint assembly is configured to allow the clamping member to deflect relative to the axis of the hydraulic actuator as the port of the elbow under test deforms.

[0023] By introducing an adaptive ball joint assembly between the force-applying end of the hydraulic actuator and the clamping component, the clamping component is allowed to deflect angularly following the deformation of the elbow port, achieving a flexible connection. This design eliminates the additional bending moment caused by forced clamping, protects the cylinder seals and elbow surface, and improves the system's adaptability to the elbow's deformation posture.

[0024] Optionally, the adaptive ball head assembly includes: A spherical groove is provided on one of the force-applying end and the clamping member; A ball-head structure is disposed in the other of the force-applying end and the clamping member. The ball-head structure is disposed in the spherical groove and slides with the spherical groove to achieve deflection movement relative to the spherical groove.

[0025] By designing a spherical groove and a ball-head structure that cooperate with each other, a multi-degree-of-freedom deflection motion is achieved through sliding contact, providing a mature and reliable mechanical solution. This structure is simple, has a high load-bearing capacity, and low frictional resistance, ensuring the long-term stable operation of the adaptive adjustment function.

[0026] Another aspect of this application provides a self-reinforcing elbow device, comprising: The elbow clamping fixture described above is used to clamp the elbow to be tested; The pressurization module is used to provide the test medium into the elbow under test; The elbow clamping fixture dynamically adjusts the clamping force on the elbow under test based on the change in the pressure of the medium inside the elbow under test.

[0027] By integrating the aforementioned elbow clamping fixture with the pressurizing module into a complete self-reinforcing processing device, a leap from a single fixture to a complete set of equipment has been achieved. This device can dynamically adjust the clamping force based on changes in internal pressure, and works in conjunction with the pressurizing module to form a system-level solution with independent commercial application value, ensuring the overall controllability of the self-reinforcing processing process.

[0028] Another aspect of this application provides a self-reinforcing method for elbows, comprising the following steps: Seal and clamp the port area of ​​the elbow to be tested; Inject the test medium into the elbow to be tested, and gradually increase the medium pressure to the self-reinforcing target pressure. The internal medium pressure of the elbow to be tested is obtained, and the clamping force applied to the port is dynamically adjusted according to the change of the medium pressure. The clamping force is adjusted to counteract the port deformation of the elbow under test caused by the increase in internal medium pressure, so as to maintain the sealing state of the port.

[0029] This method, through standardized operating procedures, acquires internal pressure data in real time during the pressurization process and dynamically adjusts the clamping force to counteract deformation and maintain a seal. This not only ensures the safety and effectiveness of the self-reinforcing treatment process but also provides a reliable process specification for ultra-high pressure elbow treatment by establishing the method steps.

[0030] Optionally, the step of sealing and clamping the port portion of the elbow to be tested includes: Connect the first and last ports of the two elbows to be tested in series so that the inner cavities of the two elbows to be tested are interconnected to form a closed pressurized circuit. The elbow is clamped to the outside of both ends of the elbow under test by two clamping members to apply a radial clamping force to the port portion of the elbow under test.

[0031] By specifically implementing a clamping process for tandem double elbows in the method, the two elbows are joined end-to-end to form a closed loop, and radial clamping forces are applied to the outer sides of both ends. This step clarifies the specific operational specifications for tandem double elbow testing, enhances the feasibility of the method, and is particularly suitable for testing scenarios requiring large capacity or specific stress distribution.

[0032] Optionally, the step of dynamically adjusting the clamping force applied to the port portion includes: The clamping member is connected via a hydraulic actuator to provide radial pressure to the clamping member along the port of the elbow to be tested. Connect the hydraulic line of the hydraulic actuator to the hydraulic line of the test medium inside the elbow under test, so that the output pressure of the hydraulic actuator increases synchronously with the pressure of the medium; or... According to a preset pressure-clamping force ratio coefficient, the output pressure of the hydraulic actuator increases as the pressure of the medium increases.

[0033] By providing two specific dynamic clamping force adjustment strategies—passive hydraulic balancing achieved through pipeline connectivity or active linear control based on a preset proportional coefficient—the flexibility of the method is increased. These two approaches are adapted to testing environments with different accuracy requirements and cost control needs, ensuring precise matching between clamping force and internal pressure changes.

[0034] In summary, this application, through the combination of a defined support frame, port clamping assembly, and hydraulic compensation mechanism, solves the problems of sealing failure and test data deviation caused by elbow port deformation under ultra-high pressure conditions in the prior art. By achieving dynamic active compensation of clamping force according to changes in internal medium pressure, this application achieves comprehensive technical advantages in improving sealing reliability, ensuring stable test boundary conditions, and improving data acquisition accuracy. Furthermore, through various specific structural layouts and control strategies, it adapts to the needs of different test scenarios, such as single elbows and double elbows in series. Attached Figure Description

[0035] To more clearly illustrate the embodiments of this application, the relevant drawings will be briefly described below. It is understood that the drawings described below are only for illustrating some embodiments of this application, and those skilled in the art can obtain many other technical features and connections not mentioned herein based on these drawings.

[0036] Figure 1 This is a schematic diagram of the self-reinforcing elbow device of this application; Figure 2 This is a schematic diagram of the structure of one embodiment of the elbow clamping fixture of this application; Figure 3 This is a schematic diagram of the structure of one embodiment of the elbow clamping fixture of this application; Figure 4 This is a schematic diagram of the structure of one embodiment of the elbow clamping fixture of this application; Figure 5 This is a schematic diagram of the adaptive ball joint assembly of the elbow clamping fixture of this application; Figure 6 This is a flowchart illustrating the steps of the elbow self-reinforcing method of this application; Explanation of reference numerals in the attached figures: 1. Support frame; 2. Port clamping assembly; 21. Ball head structure; 3. Hydraulic compensation mechanism; 31. Spherical groove; 4. Elbow to be tested; 41. Flange; 5. Test pipeline; 6. Pressure detection unit; 7. Strain detection unit; 8. Sealing joint; 9. Controller. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0038] In the field of ultra-high pressure vessel and pipeline treatment technology, particularly in the self-reinforcing treatment of elbows in ultra-high pressure tubular reactors, reliable clamping and sealing of the workpiece under test are crucial for ensuring process safety and data accuracy. These applications typically involve extremely high operating pressures, often exceeding 200 MPa, while the self-reinforcing treatment pressure can reach 650 MPa to 750 MPa. Against this backdrop, the testing system must be able to withstand enormous internal medium pressures while maintaining the stability of the elbow port position to prevent seal failure and ensure the reliability of stress-strain measurement data.

[0039] In a widely used existing technical solution, a rigid fixing method is typically used to clamp and test elbows. In this rigid fixing method, both ends of the elbow are fixed to a rigid test bench by flanges, and the port displacement is mainly restricted by the preload of the bolts. These two methods can maintain basic sealing functions under normal or low-pressure conditions, forming the basic technical background of this field.

[0040] However, the aforementioned existing technical solutions have direct technical limitations in principle. When the internal medium pressure rises to ultra-high pressure conditions, the inner wall of the elbow will undergo plastic deformation. This deformation will cause irreversible radial expansion of the elbow port, commonly known as the flaring effect, as well as axial elongation. The radial expansion and axial elongation of the port will directly destroy the sealing pressure of the intermediate sealing assembly, leading to leakage of the ultra-high pressure medium. If the bolt preload is insufficient, it will not be able to resist the deformation and cause leakage; if the preload is too large, it may cause the flange or elbow port to undergo brittle fracture or excessive elastic deformation under high pressure. This surface problem directly leads to the interruption of the testing process or safety hazards.

[0041] A deeper analysis reveals that the aforementioned surface-level problems lead to a more fundamental systemic bottleneck in practical applications. Because port deformation is not precisely compensated for, the boundary conditions experienced by the elbow during actual testing often differ from the theoretical calculation models. Theoretical models typically assume the port is fixed or free, but existing technologies cannot maintain ideal boundary conditions during the dynamic processes of pressurization, pressure holding, and pressure release. This deviation in boundary conditions results in significant errors in stress-strain measurement data, especially in the region near the port, making it impossible to accurately assess the self-reinforcing effect; for example, the accuracy of residual stress distribution is affected. Furthermore, existing technologies largely rely on static bolt pre-tightening or structural interlocking to passively resist deformation, failing to actively adjust clamping forces and constraint positions based on real-time pressure changes, making precise control throughout the entire lifecycle difficult.

[0042] Those skilled in the art might consider simply increasing the bolt preload or thickening the flange structure to address the aforementioned leakage problem. However, such obvious alternatives have significant drawbacks. Simply increasing the static preload cannot accommodate the dynamically changing deformation during pressurization and may cause over-constraint during depressurization, leading to excessively rapid elastic rebound of the elbow and resulting in a reverse impact. Furthermore, excessive static rigidity may introduce additional residual stress, interfering with test results. Therefore, how to achieve dynamic compensation for elbow port deformation without introducing excessive static stress risks has become a pressing technical challenge in this field.

[0043] In view of this, the embodiments of this application aim to provide a bend clamping fixture, a self-reinforcing treatment device and method, in order to solve or at least partially alleviate the above-mentioned technical problems.

[0044] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0045] First Implementation Method like Figure 1 As shown, this embodiment provides a elbow clamping fixture, specifically an elbow clamping fixture with deformation compensation function, mainly applied to ultra-high pressure elbow self-reinforcing treatment scenarios. The elbow clamping fixture may include a support frame 1, a port clamping assembly 2, and a hydraulic compensation mechanism 3.

[0046] The support frame 1 serves as the basic load-bearing structure and can be used to install and secure other components. In one specific embodiment, the support frame 1 can be a steel frame platform, such as a frame structure welded from aluminum profiles or heavy steel. The rigidity and stability of the support frame 1 can be configured to withstand the enormous reaction forces generated during ultra-high pressure testing.

[0047] The port clamping assembly 2 can be used to clamp the port portion of the elbow 4 under test, thereby defining the port position of the elbow 4 under test. The port clamping assembly 2 may include at least one clamping member, which may be configured to contact the port flange 51 or the end outer wall of the elbow 4 under test. In some embodiments, the port clamping assembly 2 may include two clamping members disposed opposite each other, acting on the two end ports of the elbow 4 under test respectively, or acting on opposite sides of the same port. The shape of the clamping member can be adapted according to the geometry of the port of the elbow 4 under test, for example, it may be an arc-shaped tile or a flat pressure plate.

[0048] For the elbow 4 to be tested, its port can be equipped with a flange 51 structure. The flange 51 can be used to abut against the clamping part or to connect with the sealing assembly (the structural part that seals the port of the elbow 4 to be tested). Of course, in some cases, the elbow 4 to be tested may not have a flange 51, and the sealing assembly can be fixedly connected to the elbow 4 to be tested through an external connector.

[0049] The hydraulic compensation mechanism 3 can be mounted on the support frame 1 and has a force-applying end that acts on the port clamping assembly 2. The hydraulic compensation mechanism 3 can be configured to dynamically adjust the clamping force applied through the force-applying end according to changes in the internal medium pressure of the elbow 4 under test. For example, the hydraulic compensation mechanism 3 may include a hydraulic actuator, such as a hydraulic cylinder or a hydraulic motor. The piston rod or output shaft of the hydraulic actuator can serve as the force-applying end, directly abutting against or connected to the port clamping assembly 2. When the internal medium pressure of the elbow 4 under test increases, the hydraulic compensation mechanism 3 can be triggered to increase the output pressure, thereby increasing the clamping force of the clamping member on the port of the elbow 4 under test to compensate for the port deformation caused by the increased internal medium pressure.

[0050] The elbow clamping fixture provided in this embodiment transforms the clamping process from static rigid clamping to dynamic, actively compensated clamping. In traditional solutions, the clamping force is typically a pre-set fixed value, which cannot adapt to the dynamic changes in elbow deformation during pressurization. This embodiment, however, uses a hydraulic compensation mechanism 3 to sense or respond to changes in internal medium pressure in real time, actively adjusting the clamping force. This dynamic adjustment mechanism improves sealing reliability under ultra-high pressure conditions, preventing seal separation due to port deformation. Simultaneously, stable port boundary conditions reduce vibration and displacement during testing, ensuring the accuracy of stress-strain data acquisition and improving the accuracy of test results.

[0051] In order to further realize the automatic synchronization of the internal pressure of the hydraulic compensation mechanism 3 and the elbow 4 under test, and achieve force balance without the need for complex external control algorithms, this embodiment improves the specific structure of the hydraulic compensation mechanism 3.

[0052] like Figure 1 As shown, in an improved embodiment, the hydraulic compensation mechanism 3 may include a hydraulic cylinder. This hydraulic cylinder can be connected to a test pipeline 5 that provides medium pressure to the elbow 4 under test. Specifically, the internal oil chamber of the hydraulic cylinder can be directly connected to the main or branch pipe of the test pipeline 5 via a high-pressure hose or rigid pipe. This connection method ensures that the internal oil pressure of the hydraulic cylinder is balanced with the internal medium pressure of the elbow 4 under test.

[0053] Based on the principles of hydrostatics, when the pressure of the medium in test pipeline 5 increases, the pressure is simultaneously transmitted to the internal oil chamber of the hydraulic cylinder. The piston of the hydraulic cylinder generates thrust under pressure, which acts on the force-applying end. By designing the effective working area of ​​the hydraulic cylinder piston, the clamping force applied at the force-applying end can be matched to the internal medium pressure of the elbow 4 under test. For example, if a 1:1 ratio between the clamping force and the internal pressure is required, the piston area can be designed so that the output force equals the pressure multiplied by the area; if the ratio needs to be increased or decreased, the size of the piston area can be adjusted.

[0054] This purely mechanical hydraulic automatic follow-up compensation scheme has significant technical advantages. Utilizing the physical characteristics of interconnected pipelines, the hydraulic compensation mechanism 3 responds extremely quickly, almost synchronously with the increase in internal pressure, eliminating the signal acquisition and processing delays of the electronic control system. This allows the system to quickly compensate for the elastic or plastic deformation of the elbow 4 under test during the pressure increase. Furthermore, this scheme reduces reliance on external sensors and controllers, decreases the risk of electrical component failure in ultra-high pressure environments, and improves the overall reliability and service life of the system. Simultaneously, it simplifies the control logic, reducing equipment manufacturing costs and maintenance complexity.

[0055] Second Implementation Method Based on the first embodiment, this embodiment further improves the control method of the hydraulic compensation mechanism, providing an electronically controlled active intelligent compensation scheme. Unlike the passive scheme in the first embodiment that uses pipeline connection to achieve natural pressure synchronization, this embodiment achieves precise programmable control of the clamping force by introducing sensor feedback and closed-loop control algorithms.

[0056] like Figure 1 As shown, the elbow clamping fixture provided in this embodiment can also include a support frame 1, a port clamping assembly 2, and a hydraulic compensation mechanism 3. The specific structures of the support frame 1 and the port clamping assembly 2 can be referred to the description in the first embodiment. The hydraulic compensation mechanism 3 can also include a hydraulic actuator, such as a hydraulic cylinder. The improvement lies in that the hydraulic compensation mechanism 3 is configured to accept electronic control signals to adjust the output pressure, rather than relying solely on physical pipeline connections.

[0057] To achieve precise control based on internal medium pressure, this embodiment adds a pressure detection unit 6 and a controller 9. The pressure detection unit 6 can be connected to the inside of the elbow 4 under test to acquire the internal medium pressure. In a specific embodiment, the pressure detection unit 6 can be a high-temperature, high-pressure sensor, such as a piezoresistive or piezoelectric sensor. The range of the pressure detection unit 6 can cover 0 MPa to 1000 MPa to adapt to ultra-high pressure testing environments. The controller 9 can be electrically connected to the pressure detection unit 6 and the hydraulic compensation mechanism 3. The controller 9 can be a programmable logic controller (PLC), an industrial computer, or an embedded microprocessor.

[0058] In a specific control logic, controller 9 can be used to control the hydraulic compensation mechanism 3 to output a matching pressure based on the internal medium pressure of the elbow 4 under test. For example, pressure detection unit 6 collects pressure data inside the elbow 4 under test in real time and converts it into an electrical signal, which is then sent to controller 9. Controller 9 may have a preset pressure-clamping force mapping relationship. When an increase in internal medium pressure is detected, controller 9 can calculate the required target clamping force and generate a control command, which is then sent to hydraulic compensation mechanism 3. Hydraulic compensation mechanism 3 may include an electro-hydraulic proportional valve, which can adjust the flow rate or pressure of hydraulic oil entering the hydraulic cylinder according to the control command, thereby matching the clamping force output at the force application end with the internal medium pressure of the elbow 4 under test.

[0059] The advantage of this electronically controlled active compensation scheme lies in providing a more flexible control strategy than passive hydraulic connection. In the first embodiment, the ratio of clamping force to internal pressure is mainly determined by the cylinder area, with a limited adjustment range. However, in this embodiment, a non-linear pressure-clamping force relationship can be set according to experimental requirements. For example, in the initial stage of pressure increase, a lower clamping force ratio can be set to reduce the initial stress at the port of the elbow 4 under test; as the pressure approaches the target, the clamping force ratio can be automatically increased to enhance sealing safety. This flexibility makes the scheme particularly suitable for high-precision testing scenarios or scientific research experiments, and can meet the personalized testing needs of elbows 4 of different specifications.

[0060] like Figure 1 As shown, to further improve the safety and accuracy of control, this embodiment can also introduce a direct feedback mechanism based on deformation. For this purpose, this embodiment adds a strain detection unit 7. The strain detection unit 7 can be disposed on the outer wall of the port of the elbow 4 to be tested or in the vicinity of the port clamping assembly 2, and is used to acquire strain data at the port of the elbow 4 to be tested. In a specific embodiment, the strain detection unit 7 can be a resistance strain gauge or a fiber optic grating sensor, which can be pasted or welded to the outer surface of the port of the elbow 4 to be tested, or installed on the interface between the clamping assembly and the elbow 4 to be tested.

[0061] The controller 9 can be electrically connected to the strain detection unit 7 and the hydraulic compensation mechanism 3. The controller 9 can be configured to receive strain data and, when the strain data exceeds a preset threshold, generate a pressure boosting command and send it to the hydraulic compensation mechanism 3 to increase the output pressure of the hydraulic compensation mechanism 3. For example, an axial strain safety threshold can be set. When the axial elongation strain at the port of the elbow 4 under test exceeds this threshold, it indicates that the current clamping force is insufficient to limit deformation. At this time, the controller 9 can immediately generate a pressure boosting command to drive the hydraulic compensation mechanism 3 to increase the output pressure and forcibly limit the deformation.

[0062] This strain feedback-based control logic offers significant technical advantages. Compared to relying solely on pressure feedback, directly monitoring deformation provides a more intuitive reflection of the sealing surface's condition. Increased pressure does not necessarily lead to leakage, but excessive port deformation can directly disrupt the sealing pressure. Therefore, using strain data as feedback enables result-based rather than cause-based feedback control. This more directly prevents sealing surface separation and improves system safety under extreme conditions. For example, when local defects in the material of the tested elbow 4 cause abnormal deformation, pressure feedback may fail to respond promptly, while strain feedback can immediately trigger compensation, preventing accidents.

[0063] In another preferred control strategy, to optimize the smoothness of the entire testing cycle, controller 9 can also be configured to execute closed-loop control based on a preset pressure-displacement compensation curve. Specifically, controller 9 can have a pre-set database of theoretical pressure-displacement compensation curves for elbows of different specifications. During the pressurization process, controller 9 can perform feedforward control not only based on real-time pressure or strain but also in conjunction with the preset curves. For example, when the pressure reaches a certain point, controller 9 can adjust the output of the hydraulic compensation mechanism 3 in advance to offset the expected deformation, thereby reducing feedback delay.

[0064] Furthermore, during the depressurization phase, controller 9 can execute specific synchronous proportional thrust reduction logic. When the self-reinforcing process is complete and the pump station begins depressurization, the elbow under test 4 will elastically rebound. If the clamping force decreases too quickly, the elbow under test 4 may experience a reverse impact due to excessively rapid rebound; if the clamping force decreases too slowly, it may hinder the rebound or even cause reverse plastic deformation. Therefore, controller 9 can control the output pressure of the hydraulic compensation mechanism 3 to decrease linearly or non-linearly as the medium pressure decreases, according to a preset depressurization curve. This refined process control can prevent the elbow under test 4 from experiencing a reverse impact due to excessively rapid elastic rebound, protecting the test workpiece and equipment structure, and extending its service life.

[0065] In summary, this embodiment achieves comprehensive active compensation for the deformation of the four ports of the elbow under test by integrating pressure detection, strain detection, and controller control. Compared with the passive hydraulic balancing of the first embodiment, this embodiment has significant improvements in control accuracy, safety response speed, and process adaptability, and is particularly suitable for ultra-high pressure self-reinforcing treatment scenarios with extremely high requirements for test boundary conditions.

[0066] Third Implementation Method Based on the aforementioned embodiments, this embodiment further improves the mechanical structure layout of the elbow clamping fixture, providing a radial constraint and dual-elbow series testing scheme. Unlike the previous two embodiments, which focus on control logic, this embodiment focuses on solving the radial diameter expansion problem of the elbow port and the sealing stability problem during multi-elbow series testing.

[0067] The elbow clamping fixture provided in this embodiment may also include a support frame 1, a port clamping assembly 2, and a hydraulic compensation mechanism 3. The port clamping assembly 2 may include at least two opposing clamping members. The hydraulic compensation mechanism 3 may correspondingly include at least two opposing hydraulic actuators. The force-applying ends of the two hydraulic actuators may be respectively connected to the two clamping members to drive the two clamping members to open or close relative to each other, thereby applying a clamping force to the port of the elbow to be tested. In a specific embodiment, the clamping member may be an arc-shaped tile, the inner surface of which may conform to the outer circumferential surface of the port of the elbow to be tested 4. The hydraulic actuator may be a hydraulic cylinder, the piston rod end of which is connected to the back of the clamping member.

[0068] The clamping device of this embodiment can adapt to elbows of different sizes and achieve uniform, wrap-around clamping. Through the opposing clamping device and hydraulic actuator, the system can achieve bidirectional drive of the elbow port. This bidirectional drive capability allows the fixture to not only tighten the clamp during pressurization but also open it when needed for quick loading and unloading of workpieces. Simultaneously, the uniform, wrap-around clamping avoids localized deformation of the port caused by single-point force, protecting the geometric accuracy of the elbow port.

[0069] In order to specifically compensate for the radial expansion of the four ports of the elbow under test, this embodiment limits the arrangement direction of the clamping components and the hydraulic actuator.

[0070] In an improved embodiment, the clamping members and the hydraulic actuator can be arranged radially along the port of the elbow 4 to be tested. Specifically, at least two clamping members can abut against opposite sides of the same port of the elbow 4 to apply a radial clamping force to the port of the elbow 4. Alternatively, as... Figure 2 As shown, at least two clamping elements can also abut against the outer sides of the two ends of the elbow 4 under test to apply radial clamping force to the two ends of the elbow 4 under test. For example, when the internal medium pressure of the elbow 4 under test increases, the ends of the elbow 4 under test are prone to a funneling effect, that is, radial outward expansion. At this time, the radially arranged hydraulic actuator can drive the clamping elements to apply pressure inward, directly counteracting this radial expansion trend.

[0071] Radial plastic deformation of the elbow port under ultra-high pressure is one of the main causes of seal failure. This embodiment's radial arrangement effectively suppresses radial plastic deformation of the elbow port under ultra-high pressure through specific radial direction constraints, protecting the port roundness. Maintaining port roundness is crucial for maintaining uniform contact stress in the sealing assembly, thereby preventing the formation of localized leakage channels due to port de-roundness.

[0072] In order to achieve internal cavity connectivity and ensure reliable clamping of both ends in the double-bend series test scenario, this embodiment further improves the port clamping component 2 by adding a sealing joint 8.

[0073] like Figure 3 As shown, in one specific application of this embodiment, the port clamping assembly 2 may include two sealing joints 8, which are bolted to the flanges 41 on the sidewalls of the ports of the elbows to be tested 4. The two sealing joints 8 can be used to connect the first and last ports of the two elbows to be tested 4 in series, so that the inner cavities of the two elbows to be tested 4 are interconnected to form a closed pressurized circuit. The two clamping members can be located on the outer sides of the two end ports of the elbows to be tested 4, respectively. Each clamping member can abut against the sidewalls of the ports of the two elbows to be tested 4 and the sealing joints 8.

[0074] Furthermore, the sealing joint 8 may include a support portion and a core sealing portion. The support portion may be flush with the port sidewall of the elbow 4 to be tested. The core sealing portions may be located on opposite sides of the support portion. The two core sealing portions are respectively used to extend into the ports of the two elbows 4 to be tested to seal the ports of the elbows 4 to be tested. The core sealing portion may have a through hole penetrating the support portion, which is used to connect the inner cavities of the two elbows to be tested. In a specific embodiment, the outer surface of the core sealing portion may be provided with multiple sealing grooves for installing O-rings or metal sealing rings to achieve high-pressure sealing. The end face of the support portion may serve as the force-bearing surface of the clamping member.

[0075] This tandem sealing structure provides a concrete method for implementing double-bend testing. The core seal effectively resists the erosion and leakage of high-pressure media because the higher the media pressure, the tighter the core seal tends to be. The support section provides a reliable force-bearing surface for external clamping. Applying preload to the entire assembly through the outer clamping components enhances system rigidity. This solves the problem of intermediate seal stability in double-bend tandem testing, making it possible to test two bends simultaneously and improving testing efficiency.

[0076] To further improve the geometric stability during the series testing of the double elbows, this embodiment can also introduce a lateral radial compensation scheme. This scheme, as an optimization option for the aforementioned series structure, focuses on addressing the geometric shape change of the outer side of the elbow under high pressure.

[0077] In a preferred configuration of this embodiment, a radial hydraulic cylinder can be additionally arranged on the outer side of the bend of the double elbows connected in series. Specifically, the radial hydraulic cylinder can be mounted on a lateral support of the support frame 1, and its force-applying end can point towards the apex of the arc of the bend 4 to be tested. When the internal medium pressure increases, causing the radius of curvature of the elbow to increase, i.e., when the elbow tends to open, the lateral cylinder can actively apply inward pressure.

[0078] This lateral compensation scheme offers additional technical benefits. In tandem double-elbow tests, increased internal pressure not only causes port deformation but also alters the overall geometry of the elbow, such as increasing the radius of curvature. This overall deformation exerts shear forces on the intermediate sealing joint, potentially damaging the sealing structure over time. By applying lateral constraints to the outside of the bend, this implementation suppresses changes in the overall elbow geometry. This further protects the intermediate sealing assembly from shear force damage, making it particularly suitable for self-reinforcing large-diameter, thin-walled elbows. Furthermore, this constraint helps maintain the original geometry of the elbow, resulting in a post-test elbow shape closer to the design expectation and reducing the need for subsequent calibration procedures.

[0079] In summary, this embodiment constructs a complete mechanical system for testing double elbows in series by using radially arranged clamping components, a dedicated series sealing joint 8, and an optional lateral compensation mechanism. Compared to single elbow testing, this embodiment improves testing efficiency and ensures sealing reliability and geometric stability under ultra-high pressure conditions through multi-dimensional mechanical constraints.

[0080] Fourth Implementation Method Based on the radial constraint and series test structure constructed in the third embodiment, this embodiment further provides an axial clamping scheme for the elbow under test. This scheme aims to cope with the axial thrust generated by the ultra-high pressure medium by limiting the displacement of the elbow along the pipeline axis, thereby forming an orthogonal three-dimensional protection with the radial constraint of the third embodiment.

[0081] like Figure 4 As shown, the port clamping assembly 2 in this embodiment may include two clamping members arranged opposite to each other. These two clamping members can respectively abut against the sealing assemblies at both ends of the elbow 4 to be tested. In order to drive these two clamping members to perform clamping actions, the hydraulic compensation mechanism 3 may include a hydraulic actuator, which can be mounted on the support frame 1 and has a force-applying end extending along the axial direction of the port of the elbow 4 to be tested. This force-applying end can directly act on the back of the clamping members.

[0082] During operation, when ultra-high pressure medium is injected into the inner cavity of the elbow, the medium pressure generates a huge axial thrust at the elbow port, attempting to push the elbow out of the fixture or cause the port to stretch axially. At this time, the hydraulic actuator can output axial thrust, driving the clamping component to firmly press against the outer side of the elbow port. This axial clamping force can balance the axial thrust generated by the internal medium, thereby firmly locking the elbow in the preset axial position.

[0083] The technical advantage of this axial clamping scheme lies in its effective limitation of the axial rigid displacement and plastic elongation of the elbow 4 under ultra-high pressure conditions. Combined with the radial clamping in the third embodiment, this embodiment constructs an omnidirectional clamping environment: radial clamping prevents the port from expanding out of roundness, and axial clamping prevents axial slippage or elongation of the port. This orthogonal constraint method significantly reduces stress concentration at the connection point, prevents shear failure of the seal due to excessive axial displacement, and ensures the safety and stability of the testing process.

[0084] Fifth Implementation Method Based on any of the above embodiments, this embodiment further improves the connection structure between the clamping member and the hydraulic actuator, providing an adaptive ball joint assembly. This solution aims to solve the problem of angular misalignment between the clamping member and the drive source caused by machining errors at the elbow port, installation position deviations, or deformation under stress, preventing damage to the equipment or uneven distribution of clamping force caused by lateral torque generated by rigid connection.

[0085] like Figure 5 As shown, the adaptive ball joint assembly provided in this embodiment may include a ball joint seat and a ball joint pin. In a specific embodiment, the ball joint seat may be disposed at the force-applying end of the hydraulic actuator or on the back of the clamping member. The ball joint seat may have a hemispherical spherical groove 31 machined inside. The ball joint pin may be disposed on another component that mates with it, and its end forms a ball joint structure 21 adapted to the spherical groove 31. The ball joint structure 21 may be embedded in the spherical groove 31 to form a ball joint connection. In addition, the assembly may also include a locking nut or a pressure cap for limiting the ball joint structure 21 within the spherical groove 31 to prevent it from falling out, while allowing it to rotate freely within a certain angle range.

[0086] In operation, when the hydraulic actuator drives the clamping component to move towards the elbow port, if the contact surface of the clamping component is not perfectly parallel to the surface of the elbow port 4 to be tested, the ball joint structure 21 can undergo a slight deflection and oscillation within the spherical groove 31. This adaptive oscillation allows the clamping component to automatically adjust its angle until its inner surface fully contacts the outer surface of the elbow port. Subsequently, the thrust output by the hydraulic actuator is transmitted through the normal direction of the ball joint assembly, transforming into a pure axial or radial clamping force without generating a harmful bending moment.

[0087] The technical advantage of this adaptive ball joint assembly lies in its improved tolerance of the tooling to workpiece manufacturing tolerances and installation errors. By introducing the ball joint's degree of freedom, it eliminates stress concentration caused by rigid connections, ensuring that the clamping force acts perpendicularly on the contact surface. This avoids workpiece surface damage or premature fatigue failure of fixture components caused by localized stress concentration. Simultaneously, this structure guarantees stable force transmission under complex working conditions, enhancing the reliability and service life of the entire clamping system.

[0088] Sixth Implementation Method Based on the elbow clamping fixture constructed according to any of the foregoing embodiments, this embodiment further provides a complete elbow self-reinforcing treatment device. This device combines the aforementioned mechanical clamping structure with ultra-high pressure fluid control technology, aiming to apply uniform plastic deformation pressure to the inner wall of the elbow through ultra-high pressure medium, thereby eliminating residual stress and improving the fatigue life of the elbow.

[0089] like Figure 1 As shown, the elbow self-reinforcing device provided in this embodiment may include the elbow clamping fixture described in the previous embodiments, and a pressurization module, and correspondingly, the controller 9 mentioned above. The pressurization module may include an ultra-high pressure pump, an accumulator, and a control valve assembly. The outlet of the ultra-high pressure pump can be connected to the fluid inlet of the elbow clamping fixture via the test pipeline 5. The pressure detection unit 6 can monitor the medium pressure inside the elbow cavity in real time and feed the signal back to the controller 9.

[0090] In one specific embodiment, the device may further include a safety guard that encloses the clamping fixture and the elbow 4 to be tested, to prevent accidents in extreme situations. The device utilizes the reliable clamping force provided by the aforementioned fixture as a basis, enabling the ultra-high pressure pump to increase the medium pressure to above the yield strength of the elbow material, thereby implementing self-reinforcing treatment. The elbow self-reinforcing device provided in this embodiment also possesses all the advantages mentioned in the above embodiments, and will not be repeated here.

[0091] Seventh Implementation Method This embodiment provides a self-reinforcing method for elbows. For example... Figure 6 As shown, this method can be executed using the aforementioned device and mainly includes the following steps: The first step is the clamping and sealing process, which involves sealing and clamping the port of the elbow 4 to be tested.

[0092] Specifically, such as Figure 3 As shown, two clamping elements are used to clamp the elbow 4 at both ends of the elbow 4 to apply a radial clamping force to the port portion of the elbow 4.

[0093] In this step, the first and last ports of the two elbows 4 to be tested are connected in series so that the inner cavities of the two elbows 4 to be tested are interconnected to form a closed pressurized circuit; two clamping pieces are used to clamp the elbows 4 to be tested on the outside of the two ends of the elbows 4 to apply radial clamping force to the port parts of the elbows 4 to be tested.

[0094] In this step, the elbow 4 to be tested can be placed on the support frame 1 of the elbow clamping fixture. Then, the port clamping assembly 2 is activated, driving the clamping element to abut against the outside of the port of the elbow 4 to be tested, applying a preset pre-clamping force. Simultaneously, the two ends of the elbow 4 can be sealed using the sealing joint 8 or the end face sealing assembly, forming a sealed inner cavity. During this process, the adaptive ball joint assembly can also be used to automatically adjust the clamping angle, ensuring a tight fit between the clamping surface and the elbow port.

[0095] By specifically implementing a clamping process for tandem double elbows in the method, the two elbows are joined end-to-end to form a closed loop, and radial clamping forces are applied to the outer sides of both ends. This step clarifies the specific operational specifications for tandem double elbow testing, enhances the feasibility of the method, and is particularly suitable for testing scenarios requiring large capacity or specific stress distribution.

[0096] The second step is the pressurization and pressure holding step, which involves injecting the test medium into the elbow 4 under test and controlling the medium pressure to gradually increase to the self-reinforcing target pressure; obtaining the internal medium pressure of the elbow 4 under test, and dynamically adjusting the clamping force applied to the port according to the change of the medium pressure; the adjustment of the clamping force is configured to counteract the port deformation caused by the increase of the internal medium pressure of the elbow under test, so as to maintain the sealing state of the port.

[0097] Specifically, the steps for dynamically adjusting the clamping force applied to the port include: A hydraulic actuator is connected to a clamping component to provide radial pressure along the port of the elbow under test to the clamping component; the hydraulic line of the hydraulic actuator is connected to the hydraulic line of the test medium inside the elbow under test, so that the output pressure of the hydraulic actuator increases synchronously with the pressure of the medium; or, according to a preset pressure-clamping force ratio coefficient, the output pressure of the hydraulic actuator increases as the pressure of the medium increases.

[0098] By providing two specific dynamic clamping force adjustment strategies—passive hydraulic balancing achieved through pipeline connectivity or active linear control based on a preset proportional coefficient—the flexibility of the method is increased. These two approaches are adapted to testing environments with different accuracy requirements and cost control needs, ensuring precise matching between clamping force and internal pressure changes.

[0099] In this step, the pressurization module and controller 9 are activated to inject a high-pressure medium (such as hydraulic oil or water) into the inner cavity of the elbow 4 under test. Controller 9 can control the pressurization rate, causing the inner cavity pressure to gradually increase until a preset self-reinforcing pressure value is reached. This self-reinforcing pressure value can be set to be greater than the circumferential stress on the inner wall generated by the yield strength of the elbow material, but less than its tensile strength. When the pressure reaches the set value, the system can enter the pressure holding stage, maintaining the pressure for a period of time (e.g., tens of seconds to several minutes), allowing the elbow wall material to undergo sufficient plastic flow, expanding the plastic zone from the inner wall to the outer wall, thereby forming beneficial residual compressive stress in the outer layer material after pressure relief.

[0100] By providing two specific dynamic clamping force adjustment strategies—passive hydraulic balancing achieved through pipeline connectivity or active linear control based on a preset proportional coefficient—the flexibility of the method is increased. These two approaches are adapted to testing environments with different accuracy requirements and cost control needs, ensuring precise matching between clamping force and internal pressure changes.

[0101] The third step is the pressure relief and release process. In this step, controller 9 controls the pressure relief valve to slowly open, smoothly discharging the high-pressure medium from the elbow's inner cavity and gradually reducing the internal pressure to atmospheric pressure. Slow pressure relief avoids damage to the reinforced elbow structure caused by impact loads from a sudden pressure drop. After the pressure is completely released, the port clamping assembly 2 can release the clamping parts, releasing the constraint on the elbow port. Finally, the self-reinforcing elbow can be removed from the fixture.

[0102] The self-reinforcing elbow method provided in this embodiment uses a standardized operating procedure to acquire internal pressure data in real time during the pressurization process and dynamically adjust the clamping force to counteract deformation and maintain a seal. This not only ensures the safety and effectiveness of the self-reinforcing process but also provides a reliable process specification for ultra-high pressure elbow treatment by establishing the method steps.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A clamping fixture for elbows, characterized in that, include: Supporting framework; A port clamping assembly is used to clamp the port portion of the elbow under test in order to define the port position of the elbow under test. A hydraulic compensation mechanism is mounted on the support frame and has a force-applying end that acts on the port clamping assembly; The hydraulic compensation mechanism is configured to dynamically adjust the clamping force applied through the force-applying end according to the change in the internal medium pressure of the elbow under test, so as to compensate for the port deformation of the elbow under test caused by the increase in internal medium pressure.

2. The elbow clamping fixture according to claim 1, characterized in that, The hydraulic compensation mechanism includes a hydraulic cylinder, which is connected to a test pipeline that provides medium pressure to the elbow under test. The internal oil pressure of the hydraulic cylinder is balanced with the internal medium pressure of the elbow under test, so that the force-applying end applies a clamping force that matches the internal medium pressure of the elbow under test.

3. The elbow clamping fixture according to claim 1, characterized in that, Also includes: A pressure detection unit is connected to the inside of the elbow to be tested, and is used to obtain the pressure of the medium inside the elbow to be tested; The controller is electrically connected to the pressure detection unit and the hydraulic compensation mechanism, and is used to control the output pressure of the hydraulic compensation mechanism to match the pressure of the medium inside the elbow to be tested.

4. The elbow clamping fixture according to claim 1, characterized in that, Also includes: A strain detection unit is disposed on the outer wall of the elbow port to be tested or in the vicinity of the port clamping assembly, for acquiring strain data at the elbow port to be tested. The controller is electrically connected to the strain detection unit and the hydraulic compensation mechanism. It is used to receive the strain data and generate a pressure boosting command when the strain data exceeds a preset threshold, and send it to the hydraulic compensation mechanism to increase the output pressure of the hydraulic compensation mechanism.

5. The elbow clamping fixture according to claim 1, characterized in that, The port clamping assembly includes at least two clamping members arranged opposite each other, and the hydraulic compensation mechanism includes at least two hydraulic actuators arranged opposite each other. The force-applying ends of the two hydraulic actuators are respectively connected to the two clamping members, and are used to drive the two clamping members to open or tighten relative to each other to apply a clamping force to the port of the elbow to be tested.

6. The elbow clamping fixture according to claim 5, characterized in that, The clamping member and the hydraulic actuator are respectively arranged along the radial direction of the port of the elbow to be tested; At least two of the clamping members abut against opposite sides of the same port of the elbow under test to apply radial clamping force to the port of the elbow under test; or, at least two of the clamping members abut against the outer sides of both ends of the elbow under test to apply radial clamping force to both ends of the elbow under test.

7. The elbow clamping fixture according to claim 6, characterized in that, The port clamping assembly also includes two sealing joints, which are used to connect the first and last ports of the two elbows under test in series so that the inner cavities of the two elbows under test are interconnected to form a closed pressurized circuit. The two clamping members are located on the outer sides of the two ends of the elbow to be tested, and each clamping member abuts against the sidewall of the two ends of the elbow to be tested and the sealing joint.

8. The elbow clamping fixture according to claim 7, characterized in that, The sealing joint includes: The support portion is flush with the side wall of the port of the elbow to be tested; The shaft core sealing parts are disposed on opposite sides of the support part. The two shaft core sealing parts are respectively used to extend into the ports of the two elbows to be tested to seal the ports of the elbows to be tested. The shaft core sealing parts have through holes that penetrate the support part and are used to connect the inner cavities of the two elbows to be tested.

9. The elbow clamping fixture according to claim 5, characterized in that, The clamping member and the hydraulic actuator are respectively arranged along the axial direction of the port of the elbow to be tested; At least one of the clamping members abuts against the port side of the elbow to be tested, and at least one of the clamping members abuts against the outer side of the elbow to be tested on the side away from the port, so as to apply an axial clamping force to the port of the elbow to be tested.

10. The elbow clamping fixture according to claim 5, characterized in that, An adaptive ball joint assembly is provided between the force-applying end of the hydraulic actuator and the clamping member. The adaptive ball joint assembly is configured to allow the clamping member to deflect relative to the axis of the hydraulic actuator as the port of the elbow to be tested deforms.

11. The elbow clamping fixture according to claim 10, characterized in that, The adaptive ball head assembly includes: A spherical groove is provided on one of the force-applying end and the clamping member; A ball-head structure is disposed in the other of the force-applying end and the clamping member. The ball-head structure is disposed in the spherical groove and slides with the spherical groove to achieve deflection movement relative to the spherical groove.

12. A self-reinforcing device for elbows, characterized in that, include: The elbow clamping fixture as described in any one of claims 1 to 11 is used to clamp the elbow to be tested; The pressurization module is used to provide the test medium into the elbow under test; The elbow clamping fixture dynamically adjusts the clamping force on the elbow under test based on the change in the pressure of the medium inside the elbow under test.

13. A method for self-reinforcing elbows, characterized in that, include: Seal and clamp the port area of ​​the elbow to be tested; Inject the test medium into the elbow to be tested, and gradually increase the medium pressure to the self-reinforcing target pressure. The internal medium pressure of the elbow to be tested is obtained, and the clamping force applied to the port is dynamically adjusted according to the change of the medium pressure. The clamping force is adjusted to counteract the port deformation of the elbow under test caused by the increase in internal medium pressure, so as to maintain the sealing state of the port.

14. The elbow self-reinforcing method according to claim 13, characterized in that, The steps of sealing and clamping the port portion of the elbow to be tested include: Connect the first and last ports of the two elbows to be tested in series so that the inner cavities of the two elbows to be tested are interconnected to form a closed pressurized circuit. The elbow is clamped to the outside of both ends of the elbow under test by two clamping members to apply a radial clamping force to the port portion of the elbow under test.

15. The elbow self-reinforcing method according to claim 14, characterized in that, The step of dynamically adjusting the clamping force applied to the port portion includes: The clamping member is connected via a hydraulic actuator to provide radial pressure to the clamping member along the port of the elbow to be tested. Connect the hydraulic line of the hydraulic actuator to the hydraulic line of the test medium inside the elbow under test, so that the output pressure of the hydraulic actuator increases synchronously with the pressure of the medium; or... According to a preset pressure-clamping force ratio coefficient, the output pressure of the hydraulic actuator increases as the pressure of the medium increases.

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