High-temperature bending fatigue test device and method for beam type sealing pipeline connecting assembly

Abstract

The invention relates to the technical field of airplane hydraulic guide pipe sealing connection and high-temperature fatigue test verification, and discloses a beam type sealing pipeline connecting assembly high-temperature bending fatigue test device which comprises a high-temperature comprehensive test box and a first linear guide rail. The synchronous test of more than two beam type sealing pipeline connecting assemblies is supported through multi-station design, the linear guide rail I in the high-temperature comprehensive test box can drive the sliding base to move flexibly to meet the mounting length requirements of test pieces with different specifications, and the guide rail lock can effectively prevent the sliding block from being separated; meanwhile, the Z-shaped pressurizing valve block is precisely limited through the semicircular shaft and the concave supporting seat, so that installation dislocation, medium leakage or tool damage caused by component displacement is avoided, the installation adaptability of a test piece and the overall stability of a tool are enhanced, batch verification time is greatly shortened, and support is provided for efficient development of domestic beam type sealing pipeline connecting assemblies.

Description

Technical Field

[0001] This invention relates to the field of aircraft hydraulic conduit sealing connection technology and high-temperature fatigue test verification technology, specifically to a high-temperature bending fatigue test device and method for beam-type sealed pipeline connection components. Background Technology

[0002] Hydraulic conduits, as a fundamental core component for aircraft functionality, are responsible for transmitting pressure media such as fuel, lubricating oil, and gas. Their performance and reliability directly determine the overall operational safety and efficiency of the aircraft. Beam-type sealed piping connection assemblies, with their outstanding advantages of high mobility, lightweight design, and high reliability, have become the core connection method for hydraulic piping systems in mainstream foreign aircraft models. This assembly consists of key components such as female connectors, male connectors, and threaded nuts, and can adapt to harsh operating conditions with a maximum temperature of 232℃ and a maximum pressure of 55MPa.

[0003] At present, the research and development of this type of connection component in China is still in its initial stage, and there are obvious shortcomings in related test verification technology. During the high-speed operation of aircraft, hydraulic ducts need to withstand high temperature, bending and tensile combined alternating loads for a long time, which can easily lead to fatigue failure. However, existing research at home and abroad is mostly focused on the rotational bending fatigue test of hydraulic ducts under normal temperature conditions. Research on component fatigue test under the coupled action of high temperature (≥200℃) environment and bending load is extremely scarce.

[0004] At the level of testing equipment, existing high-temperature fatigue testing devices generally have limitations: they can only test a single test piece at a time, resulting in low testing efficiency and difficulty in meeting the needs of batch verification; at the same time, they lack the ability to accurately simulate actual working conditions, making it impossible to effectively assess the material properties and fatigue life of sealing structures under dual loads of high temperature and bending. This makes it difficult to test and verify new sealing structure conduit assemblies, which restricts the research and development process of related technologies and the improvement of product reliability in China.

[0005] Therefore, a high-temperature bending fatigue testing device and method for beam-type sealed pipeline connection components is proposed to solve the above-mentioned problems. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a high-temperature bending fatigue testing device and method for beam-type sealed pipe connection components. This invention solves the problems of the lack of research on fatigue testing of beam-type sealed pipe connection components under the coupled conditions of high temperature and bending loads, the low testing efficiency caused by the inability of existing equipment to perform simultaneous testing of multiple components, and the difficulty in accurately simulating actual working conditions to effectively assess the material performance and fatigue life of the sealing structure.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly, comprising a high-temperature comprehensive test chamber, a linear guide rail one, a linear guide rail two, a sliding base, a concave support seat, a Z-shaped pressure valve block, a first adapter fixture, a second adapter fixture, a self-aligning ball bearing, a U-shaped fixing block, a fine-tuning nut, and an adjusting base plate. The first linear guide rail is fixedly installed inside the high-temperature comprehensive test chamber using countersunk bolts. Through holes are machined on both sides of the sliding base and mate with the first linear guide rail using countersunk bolts. The second linear guide rail is fixed to the upper end of the sliding base using countersunk bolts. The concave support seat is fixed with countersunk bolts. The Z-shaped pressure valve block is fixed on the linear guide rail 2; a semi-circular shaft is provided at the lower end of the Z-shaped pressure valve block, and the Z-shaped pressure valve block is connected and limited by the semi-circular keyway of the concave support seat; one end of the Z-shaped pressure valve block is threadedly connected to the beam-type sealing pipeline connection assembly through the adapter tool 1, and the other end of the Z-shaped pressure valve block is connected to the pressure source; the outer side of the beam-type sealing pipeline connection assembly is connected to the self-aligning ball bearing on the side wall of the high-temperature comprehensive test chamber through the adapter tool 2; the U-shaped fixing block is sleeved on the stepped shaft 1 and stepped shaft 2 at the upper end of the Z-shaped pressure valve block, and the fine-tuning nut is threadedly engaged with the stepped shaft 2; the adjusting base plate is connected to the internal threaded hole 6 on the side wall of the concave support seat through bolts.

[0010] Preferably, the first linear guide rail includes a guide rail and a slider, and a guide rail lock is installed on the outer side of the second linear guide rail, the guide rail lock being adapted to the slider of the second linear guide rail.

[0011] Preferably, the sliding base is machined with a countersunk hole, a threaded hole, and a threaded hole. The countersunk hole is fixed to the linear guide rail by a countersunk bolt, the threaded hole is fixed to the linear guide rail by a bolt, and the threaded hole is fixed to the adjusting base plate by a bolt.

[0012] Preferably, the concave support base plate is machined with countersunk holes two and semi-circular keyways, and the concave vertical plates on both sides are machined with internal threaded holes six. The countersunk holes two are fixed to the linear guide rail two by countersunk bolts, and the semi-circular keyways are clearance-fitted with the semi-circular shaft of the Z-shaped pressure valve block.

[0013] Preferably, the Z-shaped pressure valve block body is machined with a Z-shaped through hole, and the left and right ends of the Z-shaped pressure valve block are respectively provided with threaded hole three and threaded hole four. The threaded hole three is threadedly connected to the adapter tool one, and the threaded hole four is threadedly connected to the pressure source pipeline. The upper end of the Z-shaped pressure valve block is provided with stepped shaft one, stepped shaft two, and stepped shaft three in sequence. The stepped shaft one passes through the through hole one of the U-shaped fixing block.

[0014] Preferably, the beam-type sealed pipeline connection assembly consists of a threaded nut, a female connector, a pipe, and a stainless steel wire. The stainless steel wire is inserted into the threaded hole of the threaded nut. The female connector is assembled to form a female connector assembly. The ends of the adapter tool one and adapter tool two that are connected to the beam-type sealed pipeline connection assembly are both machined with an 8.5° inwardly tapered surface. The inwardly tapered surface fits against the lip-shaped sealing surface of the female connector of the beam-type sealed pipeline connection assembly.

[0015] Preferably, the U-shaped fixing block has an axisymmetric structure, with a U-shaped hole machined in the middle of the U-shaped fixing block. Through hole one and through hole two are respectively provided at the upper and lower ends of the U-shaped hole. The diameter of through hole one is larger than that of through hole two. Through hole one is clearance-fitted with the stepped shaft one of the Z-shaped pressure valve block. Through hole two is adapted to the stepped shaft three and the fixing nut.

[0016] Preferably, the fine-tuning nut has a rotating axisymmetric structure, and a blind hole is uniformly machined on the circumference of the fine-tuning nut. The blind hole is used to fit a hexagonal wrench. A threaded hole five is machined in the middle of the fine-tuning nut. The threaded hole five engages with the external thread of the stepped shaft two of the Z-shaped pressure valve block. The stepped shaft two is threadedly engaged with the threaded hole five of the fine-tuning nut. The stepped shaft three is fixed by the nut and the through hole two of the U-shaped fixing block.

[0017] Preferably, the adjusting base plate has an axisymmetric structure, and a countersunk through hole is machined on the upper surface of the adjusting base plate. The countersunk through hole is fixed to the threaded hole of the sliding base by a bolt. The end face of the adjusting base plate is provided with a U-shaped groove one and a U-shaped groove two. The hexagonal head of the hexagonal bolt is placed in the U-shaped groove two. The U-shaped groove one restricts the bolt from moving along the axis. The bolt shank passes through the U-shaped groove one and is threadedly connected to the threaded hole six on the side wall of the concave support seat.

[0018] A method for high-temperature bending fatigue testing of a beam-type sealed pipe connection assembly further includes the following steps:

[0019] Step 1: When assembling the test piece, first insert the stainless steel wire into the threading hole of the threading nut, and use a special rolling tool and equipment to press the pipe into the groove of the female connector to assemble a beam-type sealed pipeline connection assembly; connect adapter one and adapter two to the two ends of the beam-type sealed pipeline connection assembly respectively, and use the 8.5° inner oblique cone surface of the two to fit with the lip sealing surface of the female connector to achieve a seal;

[0020] Step 2: During tooling installation and debugging, according to the test piece specifications, move the sliding base along linear guide rail 1, adjust it to the appropriate installation length, and then fix it with countersunk bolts; move the concave support along linear guide rail 2, so that its semi-circular keyway and the semi-circular shaft of the Z-shaped pressure valve block are fitted together to complete the limit; pass the upper end of the Z-shaped pressure valve block through the through hole 1 of the U-shaped fixing block and the threaded hole 5 of the fine-adjusting nut in sequence, and fix the U-shaped fixing block with the nut on the stepped shaft 3; connect the beam-type sealing pipeline connection assembly to the self-aligning ball bearing on the side wall of the high-temperature comprehensive test chamber via adapter tool 2, and connect the other end of the Z-shaped pressure valve block to the pressure source pipeline;

[0021] Step 3: When initial stress and strain adjustment is required, attach strain gauges 5mm away from the test end of the beam-type sealed pipe connection assembly. Calculate the target bending stress based on the tensile strength and elastic modulus of the pipe material. Adjust the horizontal stress and strain by rotating the bolts on the base plate to drive the concave support seat to move back and forth. Use a hexagonal wrench inserted into the blind hole of the fine-tuning nut to rotate and drive the Z-shaped pressure valve block to move up and down to adjust the vertical stress and strain. Complete the initial stress and strain calibration by adjusting the displacement of the self-aligning ball bearing.

[0022] Step 4: When it is necessary to set the experimental parameters, turn off the high temperature comprehensive test chamber, start the equipment and set the test temperature to 200℃, keep it sealed until the temperature inside the chamber stabilizes; introduce pressure medium into the Z-shaped through hole of the Z-shaped pressure valve block through the pressure source, adjust the test pressure to 35MPa and keep it stable;

[0023] Step 5: When conducting the high-temperature bending fatigue test, start the drive shaft connected by the self-aligning ball bearing to provide rotational bending power, and carry out at least 10^7 high-temperature rotational bending fatigue tests according to the test method in section 3.3 of HB6442; during the test, the sealing performance and structural integrity of the test piece are monitored in real time through the failure monitoring function of the high-temperature comprehensive test chamber 1.

[0024] Step Six: Test Completion and Data Recording: After the test reaches the preset number of times or the test piece fails, stop the power source and heat source, and wait for the high-temperature comprehensive test chamber to cool naturally to room temperature before releasing the pressure; disassemble the test piece and each tooling component, record the number of tests, failure mode, stress-strain change curves and other data, and complete the test report.

[0025] (III) Beneficial Effects

[0026] Compared with the prior art, the present invention provides a high-temperature bending fatigue testing device and method for beam-type sealed pipeline connection components, which has the following beneficial effects:

[0027] 1. This high-temperature bending fatigue testing device for beam-type sealed pipeline connection components supports simultaneous testing of ≥2 beam-type sealed pipeline connection components through a multi-station design. The linear guide rail inside the high-temperature integrated test chamber allows for flexible movement of the sliding base, adapting to the installation length requirements of different test pieces. The guide rail lock effectively prevents the slider from disengaging. Simultaneously, the Z-shaped pressure valve block is precisely positioned via a semi-circular shaft and a concave support seat, preventing installation misalignment, media leakage, or tooling damage caused by component displacement. This enhances the adaptability of test piece installation and the overall stability of the tooling, while significantly shortening batch verification time, providing support for the efficient development of beam-type sealed pipeline connection components in China.

[0028] 2. This high-temperature bending fatigue testing device for beam-type sealed pipeline connection components consists of a beam-type sealed pipeline connection component assembled from components such as threaded nuts. The 8.5° inner oblique cone surfaces of the first and second adapters are sealed and fitted to the female connector. The Z-shaped through hole of the Z-shaped pressure valve block is connected to the pressure source, which stably applies a pressure of 35MPa. This device can prevent medium leakage and pressure instability caused by poor sealing, avoid pressure drop caused by loose connection, enhance sealing reliability and pressure stability, and improve the authenticity of test results.

[0029] 3. This high-temperature bending fatigue testing device for beam-type sealed pipeline connection components allows for horizontal stress and strain adjustment by adjusting the fit between the base plate and the concave support seat, which in turn allows the rotatable bolts to drive the concave support seat to move back and forth. The U-shaped fixing block and the fine-tuning nut work together to drive the Z-shaped pressure valve block to move up and down, completing the vertical stress fine-tuning. Simultaneously, strain gauges are attached to the test piece 5mm away from the test end. The target bending stress is calculated by combining the tensile strength and elastic modulus of the pipe material. Initial stress calibration is completed by calibrating the displacement offset of the self-aligning ball bearing, effectively avoiding data distortion and abnormal failure of the test piece caused by excessive stress deviation or lack of calibration. This provides reliable data support for accurate analysis of component fatigue life.

[0030] 4. This beam-type sealed pipeline connection component high-temperature bending fatigue testing device provides a stable high temperature of 200℃ in the high-temperature comprehensive test chamber, and the self-aligning ball bearing connected to the drive shaft provides rotational bending power. It can carry out 10^7 tests according to the standard. The internal function monitors failure in real time, which can prevent risks caused by uneven temperature, power interruption or failure to be monitored, enhance the realism of working condition simulation, loading continuity and test safety, and can also record data completely. Attached Figure Description

[0031] Figure 1 This is a front view schematic diagram of the high-temperature bending fatigue testing device of the present invention;

[0032] Figure 2 This is a front view schematic diagram of the linear guide rail structure of the present invention;

[0033] Figure 3 This is a front view of the sliding base structure of the present invention;

[0034] Figure 4 This is a front view schematic diagram of the concave support base of the present invention;

[0035] Figure 5 This is a front view schematic diagram of the Z-shaped pressure valve block of the present invention;

[0036] Figure 6 This is a front view structural schematic diagram of the beam-type sealed pipeline connection assembly of the present invention;

[0037] Figure 7 This is a front view schematic diagram of the spiral-shaped fixing block of the present invention;

[0038] Figure 8 This is a front view schematic diagram of the fine-tuning nut structure of the present invention;

[0039] Figure 9 This is a front view schematic diagram of the adjustable base plate structure of the present invention.

[0040] In the diagram: 1. High-temperature comprehensive test chamber; 2. Linear guide rail one; 3. Sliding base; 4. Linear guide rail two; 5. Guide rail lock; 6. Concave support seat; 7. Z-shaped pressure valve block; 8. Adapter fixture one; 9. Beam-type sealing pipeline connection assembly; 10. Adapter fixture two; 11. Self-aligning ball bearing; 12. U-shaped fixing block; 13. Fine-tuning nut; 14. Adjusting base plate; 15. Guide rail; 16. Slider; 17. Countersunk hole one; 18. Threaded hole one; 19. Threaded hole two; 20. 21. Countersunk hole 2; 22. Semicircular keyway; 23. Internal threaded hole 6; 24. Threaded hole 3; 25. Stepped shaft 1; 26. Stepped shaft 2; 27. Stepped shaft 3; 28. Stepped shaft 3; 29. ​​Threaded hole 4; 30. Threaded nut; 31. Female connector; 32. Pipe; 33. Stainless steel wire; 34. U-shaped hole; 35. Through hole 1; 37. Through hole 2; 38. Blind hole; 39. Threaded hole 5; 40. Countersunk through hole; 41. U-shaped groove 1; 42. U-shaped groove 2; 230. Semicircular shaft. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Please see Figure 1 - Figure 9As shown, a high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly includes a high-temperature comprehensive test chamber 1, a linear guide rail 1 2, a linear guide rail 2 4, a sliding base 3, a concave support seat 6, a Z-shaped pressure valve block 7, a first adapter 8, a second adapter 10, a self-aligning ball bearing 11, a U-shaped fixing block 12, a fine-tuning nut 13, and an adjusting base plate 14. The linear guide rail 1 2 is fixedly installed inside the high-temperature comprehensive test chamber 1 by countersunk bolts. Through holes are machined on both sides of the sliding base 3 and it is engaged with the linear guide rail 1 2 by countersunk bolts. The upper end of the sliding base 3 is fixed with the linear guide rail 2 4 by countersunk bolts. The concave support seat 6 is fixed to the linear guide rail 2 4 by countersunk bolts. The lower end of the Z-shaped pressure valve block 7 is provided with a semi-circular shaft 230. The Z-shaped pressure valve block 7 is connected and limited by the semi-circular keyway 21 of the concave support seat 6. One end of the Z-shaped pressure valve block 7 is threadedly connected to the beam-type sealing pipeline connection assembly 9 through the adapter tool 1 8, and the other end of the Z-shaped pressure valve block 7 is connected to the pressure source. The outer side of the beam-type sealing pipeline connection assembly 9 is connected to the self-aligning ball bearing 11 on the side wall of the high-temperature comprehensive test chamber 1 through the adapter tool 2 10. The U-shaped fixing block 12 is sleeved on the upper end of the Z-shaped pressure valve block 7, the stepped shaft 1 26 and the stepped shaft 2 27, and the fine-tuning nut 13 is threadedly engaged with the stepped shaft 2 27. The adjusting base plate 14 is connected to the threaded hole 6 22 on the side wall of the concave support seat 6 through bolts.

[0043] First, the linear guide rail 12 includes a guide rail 15 and a slider 16. A guide rail lock 5 is installed on the outside of the linear guide rail 24. The guide rail lock 5 is adapted to the slider 16 of the linear guide rail 24. Through the sliding cooperation between the guide rail 15 and the slider 16, the sliding base 3 can move back and forth along the axis of the linear guide rail 12, thereby flexibly adjusting the installation length of the test assembly and adapting to beam-type sealed pipeline connection assemblies 9 of different specifications. The guide rail lock 5 can effectively limit the movement range of the slider 16, prevent the slider 16 from falling off the guide rail 15, avoid damage to the tooling structure or interruption of the test due to the slider 16 falling off, ensure the stability and safety of the movement of each component during the test, and lay the foundation for the accurate installation and loading of the test piece.

[0044] Secondly, the sliding base 3 is machined with countersunk hole 17, threaded hole 18, and threaded hole 19. Countersunk hole 17 is fixed to linear guide rail 2 by countersunk bolts, threaded hole 18 is fixed to linear guide rail 4 by bolts, and threaded hole 19 is fixed to adjusting base plate 14 by bolts. The cooperation of countersunk hole 17 and countersunk bolts enables the sliding base 3 to be detachably fixed on linear guide rail 2, which not only ensures the stability of the sliding base 3 during the test, but also facilitates the adjustment of its position according to the test requirements. The connection method of threaded hole 18 and bolts ensures the firmness of the connection between linear guide rail 4 and sliding base 3, and prevents linear guide rail 4 from loosening or displacing during the stress process. The fixed connection of threaded hole 19 and adjusting base plate 14 enables adjusting base plate 14 to be stably installed on sliding base 3, providing reliable support for subsequent adjustment of horizontal stress and strain. The overall structural design realizes the orderly connection of each component, enhancing the overall stability and assembly flexibility of the tooling.

[0045] Furthermore, the concave support base 6 has a countersunk hole 20 and a semi-circular keyway 21 machined on its base plate, and internal threaded holes 22 machined on the concave vertical plates on both sides. The countersunk hole 20 is fixed to the linear guide rail 4 by countersunk bolts. The semi-circular keyway 21 is clearance-fitted with the semi-circular shaft 230 of the Z-shaped pressure valve block 7 and is fixed to the linear guide rail 4 by countersunk bolts. The semi-circular keyway 21 is clearance-fitted with the semi-circular shaft 230 of the Z-shaped pressure valve block 7. The countersunk hole 20 and the countersunk bolt securely fix the concave support 6 on the linear guide rail 4, ensuring that the concave support 6 can move synchronously with the linear guide rail 4 along the axial direction, meeting the position adjustment requirements under different test scenarios. The clearance fit between the semi-circular keyway 21 and the semi-circular shaft 230 of the Z-shaped pressure valve block 7 provides a precise fixing and limiting function for the Z-shaped pressure valve block 7, preventing the Z-shaped pressure valve block 7 from shifting left or right or rotating during the test. This avoids problems such as pressure medium leakage and load direction deviation caused by the displacement of the Z-shaped pressure valve block 7, ensuring that the Z-shaped pressure valve block 7 can stably transmit pressure and bear load, providing structural protection for the smooth conduct of the test.

[0046] Furthermore, the Z-shaped pressure valve block 7 is machined with Z-shaped through holes. Threaded holes 24 (third) and 29 (fourth) are respectively provided at the left and right ends of the Z-shaped pressure valve block 7. Threaded hole 24 is threadedly connected to adapter 8, and threaded hole 29 is threadedly connected to the pressure source pipeline. The upper end of the Z-shaped pressure valve block 7 is sequentially provided with stepped shafts 26 (first), 27 (second), and 28 (third). Stepped shaft 26 passes through the through hole 35 of the U-shaped fixing block 12. The Z-shaped through hole design provides a channel for the transmission of pressure medium, allowing the pressure medium delivered by the pressure source to smoothly pass through the Z-shaped pressure valve block 7 into adapter 8, and then be transmitted to the beam-type sealing pipeline connection assembly 9, thus achieving… Stable loading of 35MPa test pressure; threaded connection between threaded hole 324 and adapter tool 8, and threaded hole 429 and pressure source pipeline, ensuring the sealing and firmness of the connection of each component, and avoiding leakage of pressure medium during transmission; stepped shaft 26 passes through the through hole 35 of the U-shaped fixing block 12, and together with the U-shaped fixing block 12 and the fine adjustment nut 13, realizes the adjustment of the vertical position of the Z-shaped pressure valve block 7, thereby adjusting the bending stress and strain of the test component in the vertical direction to meet the test requirements for different stress conditions. At the same time, the structural design of the stepped shaft also enhances the overall strength of the Z-shaped pressure valve block 7, enabling it to withstand the load under high temperature and high pressure conditions.

[0047] Furthermore, the beam-type sealed pipe connection assembly 9 consists of a threaded nut 30, a female connector 31, a pipe 32, and a stainless steel wire 33. The stainless steel wire 33 is inserted into the threaded hole of the threaded nut 30. The female connector 31 is assembled to form the female connector 31 assembly. The ends of the adapter 1 8 and adapter 2 10 that connect to the beam-type sealed pipe connection assembly 9 are both machined with an 8.5° inwardly tapered surface. The inwardly tapered surface fits against the lip-shaped sealing surface of the female connector 31 of the beam-type sealed pipe connection assembly 9. Through standardized assembly, the structural integrity and stability of the beam-type sealed pipe connection assembly 9 are ensured. The assembly state of this component in the actual aircraft hydraulic pipeline is simulated. The 8.5° inner oblique cone surface of the adapter tooling and the lip sealing surface of the female connector 31 are closely fitted to form a double sealing structure, which greatly improves the sealing performance under high temperature and high pressure conditions, effectively prevents leakage of pressure medium, and avoids problems such as unstable test pressure and distorted test data due to poor sealing. At the same time, the design of the adapter tooling realizes the effective connection between the beam-type sealing pipeline connection component 9 and the Z-shaped pressure valve block 7 and the self-aligning ball bearing 11, ensuring that the test force and pressure can be accurately transmitted to the test piece, and ensuring the effectiveness and reliability of the test.

[0048] Furthermore, the U-shaped fixing block 12 has an axisymmetric structure. A U-shaped hole 34 is machined in the middle of the U-shaped fixing block 12. Through holes 35 and 37 are respectively provided at the upper and lower ends of the U-shaped hole 34. The diameter of through hole 35 is larger than that of through hole 37. Through hole 35 is clearance-fitted with the stepped shaft 26 of the Z-shaped pressure valve block 7. Through hole 37 is adapted to the stepped shaft 28 and the fixing nut. By tightening the fixing nut, the U-shaped fixing block 12 and the Z-shaped pressure valve block 7 are fixedly connected, ensuring that the relative position of the U-shaped fixing block 12 and the Z-shaped pressure valve block 7 is stable during the test. This provides support for the fine-tuning nut 13 to adjust the vertical position of the Z-shaped pressure valve block 7, ensuring the accuracy of stress adjustment.

[0049] Furthermore, the fine-tuning nut 13 has a rotary axisymmetric structure. Six blind holes 38 are uniformly machined on the circumference of the fine-tuning nut 13. These blind holes 38 are used to fit a hex wrench. A threaded hole 39 is machined in the center of the fine-tuning nut 13. This threaded hole 39 engages with the external thread of the stepped shaft 27 of the Z-shaped pressure valve block 7. The stepped shaft 27 is threadedly engaged with the threaded hole 39 of the fine-tuning nut 13. The stepped shaft 28 is fixed to the through hole 37 of the U-shaped fixing block 12 via a nut. The threaded engagement of the threaded hole 39 with the stepped shaft 27 converts the rotational motion into the vertical linear motion of the Z-shaped pressure valve block 7, achieving fine-tuning of the bending stress and strain of the test component in the vertical direction. This provides high adjustment accuracy and meets the precise control requirements of different stress values ​​in the test. The fixed connection between the stepped shaft 28 and the U-shaped fixing block 12 further restricts the axial displacement of the Z-shaped pressure valve block 7, ensuring stable position after fine-tuning and guaranteeing a constant stress state during the test.

[0050] Finally, the adjusting base plate 14 has an axisymmetric structure. The upper end face of the adjusting base plate 14 is machined with a countersunk through hole 40, which is fixed to the threaded hole 19 of the sliding base 3 by bolts. The end face of the adjusting base plate 14 is provided with a U-shaped groove 41 and a U-shaped groove 42. The hexagonal head of the hexagonal bolt is placed in the U-shaped groove 42. The U-shaped groove 41 restricts the bolt from moving along the axis. The bolt shank passes through the U-shaped groove 41 and is threadedly connected to the threaded hole 22 on the side wall of the concave support 6. By rotating the bolt, the thread engagement between the bolt and the threaded hole 22 of the concave support 6 drives the concave support 6 to reciprocate along the linear guide rail 4, thereby adjusting the bending stress and strain of the test component in the horizontal direction. The adjustment process is simple and precise, and can effectively control the stress value in the horizontal direction, ensuring that the stress on the test piece meets the design requirements and providing a guarantee for the accuracy of the test data.

[0051] A method for high-temperature bending fatigue testing of a beam-type sealed pipe connection assembly 9, further comprising the following steps:

[0052] Step 1: When assembling the test piece, first insert the stainless steel wire 33 into the threading hole of the threading nut 30, and use a special rolling tool and equipment to press the pipe 32 into the groove of the female connector 31 to form a beam-type sealed pipeline connection assembly 9; connect the adapter tool 1 8 and the adapter tool 2 10 to both ends of the beam-type sealed pipeline connection assembly 9 respectively, and use the 8.5° inner oblique cone surface of the two to fit with the lip sealing surface of the female connector 31 to achieve a seal;

[0053] Step 2: During tooling installation and debugging, according to the test piece specifications, move the sliding base 3 along linear guide rail 1 2, adjust it to the appropriate installation length, and then fix it with countersunk bolts; move the concave support 6 along linear guide rail 2 4, so that its semi-circular keyway 21 and the semi-circular shaft 230 of the Z-shaped pressure valve block 7 are fitted together to complete the limit; pass the upper end of the Z-shaped pressure valve block 7 through the through hole 1 35 of the U-shaped fixing block 12 and the threaded hole 5 39 of the fine-adjusting nut 13 in sequence, and fix the U-shaped fixing block 12 with the nut on the stepped shaft 3 28; connect the beam-type sealing pipeline connection assembly 9 to the self-aligning ball bearing 11 on the side wall of the high-temperature comprehensive test chamber 1 via the adapter tool 2 10, and connect the other end of the Z-shaped pressure valve block 7 to the pressure source pipeline;

[0054] Step 3: When initial stress and strain adjustment is required, attach strain gauges 5mm away from the test end of the beam-type sealed pipe connection assembly 9, and calculate the target bending stress based on the tensile strength and elastic modulus of the pipe 32; adjust the horizontal stress and strain by rotating the bolts on the base plate 14 to drive the concave support seat 6 to move back and forth; use a hexagonal wrench inserted into the blind hole 38 of the fine-tuning nut 13 to rotate, drive the Z-shaped pressure valve block 7 to move up and down, and adjust the vertical stress and strain; complete the initial stress and strain calibration by adjusting the displacement of the self-aligning ball bearing 11.

[0055] Step 4: When it is necessary to set the experimental parameters, close the high temperature comprehensive test chamber 1, start the equipment and set the test temperature to 200℃, keep it sealed until the temperature inside the chamber stabilizes; introduce pressure medium into the Z-shaped through hole of the Z-shaped pressure valve block 7 through the pressure source, adjust the test pressure to 35MPa and keep it stable.

[0056] Step 5: When conducting the high-temperature bending fatigue test, start the drive shaft connected to the self-aligning ball bearing 11 to provide rotational bending power, and conduct at least 10^7 high-temperature rotational bending fatigue tests according to the test method in section 3.3 of HB6442; during the test, the sealing performance and structural integrity of the test piece are monitored in real time through the failure monitoring function of the high-temperature comprehensive test chamber 1.

[0057] Step Six: Test Completion and Data Recording: After the test reaches the preset number of times or the test piece fails, stop the power source and heat source, and wait for the high-temperature comprehensive test chamber 1 to cool naturally to room temperature before releasing the pressure; disassemble the test piece and each tooling component, record the number of tests, failure mode, stress-strain change curves and other data, and complete the test report.

[0058] Working Principle: The core of this device simulates the actual working conditions of aircraft hydraulic pipelines. Through the combined effects of high temperature environment, pressure loading, and rotational bending power, it achieves fatigue performance testing of beam-type sealed pipeline connection component 9. Simultaneously, it supports simultaneous testing of multiple test pieces to improve efficiency. The high-temperature comprehensive test chamber 1 provides a closed environment for the test. Inside, linear guide rail 1 2 is fixed by countersunk bolts. The sliding base 3, through a through hole, mates with linear guide rail 2 and can move along the guide rail axis to adapt to the installation length requirements of test pieces of different specifications. After adjustment, it is locked in place by countersunk bolts. Linear guide rail 2 4 is fixed to the upper end of the sliding base 3, and a concave support seat 6 is installed by countersunk bolts. The guide rail lock 5 is adapted to the slider 16 of linear guide rail 2 4 to prevent the slider 16 from disengaging. To ensure motion stability, the lower semi-circular shaft 230 of the Z-shaped pressure valve block 7 and the semi-circular keyway 21 of the concave support seat 6 are fitted with a clearance to achieve precise positioning, preventing the Z-shaped pressure valve block 7 from shifting during the test. This prevents misalignment of the test piece due to displacement deviation of the sliding base 3 and the concave support seat 6, and avoids pressure medium leakage or deviation of the loading force direction caused by the Z-shaped pressure valve block 7 shifting. It also prevents the slider 16 of the linear guide rail 4 from disengaging from the guide rail 15, which could cause tooling damage or test interruption, and enhances the adaptability of the test piece installation. It is compatible with beam-type sealed pipeline connection components 9 of different specifications. This not only enhances the adaptability of the test piece installation and the overall stability of the tooling, but also significantly shortens the batch verification time, providing support for the efficient development of beam-type sealed pipeline connection components 9 in China.

[0059] The beam-type sealed pipeline connection assembly 9 is assembled from a threaded nut 30, a female connector 31, a pipe 32, and a stainless steel wire 33. The 8.5° inner conical surface of the connecting end of the adapter 1 8 and adapter 2 10 fits tightly with the lip-shaped sealing surface of the female connector 31, forming a reliable seal. The Z-shaped pressure valve block 7 has a Z-shaped through hole machined into its main body. One end is threaded to adapter 1 8 through threaded hole 3 24, and the other end is connected to the pressure source pipeline through threaded hole 4 29. The pressure medium is delivered to the beam-type sealed pipeline connection assembly 9 through the Z-shaped through hole and adapter 1 8. The stable loading of the 35MPa test pressure prevents leakage of the pressure medium under high temperature and high pressure conditions due to poor sealing surface contact, avoiding the impact of unstable pressure loading on the accuracy of fatigue test data; it also prevents loose connection between the Z-shaped pressure valve block 7 and the adapter tool 8 and the pressure source pipeline, which could lead to a sudden drop in pressure or media leakage, thus enhancing sealing reliability. The double sealing structure ensures sealing performance under high temperature and high pressure conditions; and it enhances the stability of pressure loading, ensuring that the 35MPa test pressure acts continuously and evenly on the test piece, thereby improving the authenticity and validity of fatigue test results.

[0060] Horizontal adjustment: The adjusting base plate 14 is fixed to the threaded hole 19 of the sliding base 3 through the countersunk hole 40. The bolts in its U-shaped groove 41 and U-shaped groove 42 engage with the internal threaded hole 22 of the concave support 6. Rotating the bolts can drive the concave support 6 to move back and forth, adjusting the horizontal stress and strain of the test piece. Vertical adjustment: The U-shaped fixing block 12 is sleeved on the stepped shaft 26 and stepped shaft 27 of the Z-shaped pressure valve block 7. The fine-tuning nut 13 engages with the external thread of the stepped shaft 27 through the threaded hole 39. By inserting a hexagonal wrench into the blind hole 38 of the fine-tuning nut 13 and rotating it, the Z-shaped pressure valve block 7 can be driven to move up and down, precisely adjusting the vertical stress and strain. Initial calibration: Strain gauges are attached to the beam-type sealed pipe connection assembly 9 5mm away from the test end. The target bending stress is calculated based on the tensile strength and elastic modulus of the pipe 32. The initial stress-strain calibration is completed by adjusting the displacement of the self-aligning ball bearing 11. This prevents excessive deviations in stress adjustment in the horizontal and vertical directions, avoiding discrepancies between the actual stress on the test piece and the target bending stress, which could lead to distorted test data. It also prevents premature failure of the test piece or failure to reach the fatigue life threshold due to uncalibrated initial stress-strain, which could affect the judgment of test results. This enhances the accuracy of stress adjustment, enables independent fine-tuning of stress in the horizontal and vertical directions, meets the stress control requirements under different test conditions, and improves the accuracy of test data.

[0061] The high-temperature environment is provided by the high-temperature integrated test chamber 1. After the chamber is closed, the temperature is set to 200℃ and kept sealed until the internal temperature stabilizes, simulating the high-temperature working conditions of aircraft hydraulic lines. The self-aligning ball bearing 11 is installed in the bearing slot on the side wall of the high-temperature integrated test chamber 1 and connected to the beam-type sealed pipeline connection assembly 9 via the adapter tool 2 10. The connected drive shaft provides rotational bending power. According to the test method in section 3.3 of HB6442, at least 10^7 high-temperature rotational bending fatigue tests are carried out. During the test, the failure monitoring function of the high-temperature integrated test chamber 1 monitors the sealing performance and structural integrity of the test piece in real time until the preset number of tests is reached or failure is detected, preventing the temperature inside the high-temperature integrated test chamber 1 from rising. Uneven distribution or poor sealing should be avoided to prevent excessive deviation between simulated operating conditions and the actual high-temperature environment of aircraft hydraulic pipelines; unstable installation of the self-aligning ball bearing 11 should be prevented from causing interruption of rotational bending power transmission, thus avoiding interruption of the test; failure to monitor failure in real time should be prevented from leading to tooling failure or safety hazards due to continued loading after the test piece is damaged, thus enhancing the realism of the operating condition simulation and replicating the actual working conditions of aircraft hydraulic pipelines through a stable 200℃ high-temperature environment; the continuity of fatigue loading should be enhanced to ensure stable output of rotational bending power and ensure the smooth conduct of at least 10^7 fatigue tests; the safety and controllability of the test should be enhanced, and real-time failure monitoring can promptly detect problems with the test piece, prevent the risk from escalating, and at the same time, complete data recording of the test process should be performed.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly, comprising a high-temperature comprehensive test chamber (1), a linear guide rail one (2), a linear guide rail two (4), a sliding base (3), a concave support seat (6), a Z-shaped pressure valve block (7), a first adapter tool (8), a second adapter tool (10), a self-aligning ball bearing (11), a U-shaped fixing block (12), a fine-tuning nut (13), and an adjusting base plate (14), characterized in that: The high-temperature comprehensive test chamber (1) is equipped with a linear guide rail 1 (2) fixed inside by countersunk bolts. The sliding base (3) has through holes on both sides and is fitted with the linear guide rail 1 (2) by countersunk bolts. The upper end of the sliding base (3) is fixed with a linear guide rail 2 (4) by countersunk bolts. The concave support seat (6) is fixed to the linear guide rail 2 (4) by countersunk bolts. The lower end of the Z-shaped pressure valve block (7) is provided with a semi-circular shaft (230). The Z-shaped pressure valve block (7) is connected and limited by the semi-circular keyway (21) of the concave support seat (6). One end of the Z-shaped pressure valve block (7) is connected by an adapter. One (8) is threadedly connected to the beam-type sealing pipeline connection assembly (9), and the other end of the Z-shaped pressure valve block (7) is connected to the pressure source; the outer side of the beam-type sealing pipeline connection assembly (9) is connected to the self-aligning ball bearing (11) on the side wall of the high-temperature comprehensive test chamber (1) via the adapter tool two (10); the spiral-shaped fixing block (12) is sleeved on the upper end of the Z-shaped pressure valve block (7) stepped shaft one (26) and stepped shaft two (27), and the fine-tuning nut (13) is threadedly engaged with stepped shaft two (27); the adjusting base plate (14) is connected to the inner threaded hole six (22) on the side wall of the concave support seat (6) by bolts.

2. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The first linear guide rail (2) includes a guide rail (15) and a slider (16). The second linear guide rail (4) has a guide rail lock (5) installed on its outer side. The guide rail lock (5) is adapted to the slider (16) of the second linear guide rail (4).

3. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The sliding base (3) is machined with countersunk hole one (17), threaded hole one (18) and threaded hole two (19). Countersunk hole one (17) is fixed to linear guide one (2) by countersunk bolt. Threaded hole one (18) is fixed to linear guide two (4) by bolt. Threaded hole two (19) is fixed to adjusting base plate (14) by bolt.

4. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The concave support base (6) has a countersunk hole 2 (20) and a semi-circular keyway (21) on its bottom plate, and internal threaded holes 6 (22) on the concave vertical plates on both sides. The countersunk hole 2 (20) is fixed to the linear guide rail 2 (4) by countersunk bolts. The semi-circular keyway (21) is clearance-fitted with the semi-circular shaft (230) of the Z-shaped pressure valve block (7).

5. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The Z-shaped pressurizing valve block (7) has a Z-shaped through hole machined on its main body. The left and right ends of the Z-shaped pressurizing valve block (7) are respectively provided with threaded hole three (24) and threaded hole four (29). The threaded hole three (24) is threadedly connected to the adapter tool one (8), and the threaded hole four (29) is threadedly connected to the pressure source pipeline. The upper end of the Z-shaped pressurizing valve block (7) is provided with stepped shaft one (26), stepped shaft two (27), and stepped shaft three (28) in sequence. The stepped shaft one (26) passes through the through hole one (35) of the U-shaped fixing block (12).

6. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The beam-type sealed pipeline connection assembly (9) consists of a threaded nut (30), a female connector (31), a pipe (32), and a stainless steel wire (33). The stainless steel wire (33) is inserted into the threaded hole of the threaded nut (30). The female connector (31) is assembled to form a female connector (31) assembly. The end of the adapter tool one (8) and adapter tool two (10) connected to the beam-type sealed pipeline connection assembly (9) is machined with an 8.5° inwardly inclined conical surface. The inwardly inclined conical surface fits against the lip sealing surface of the female connector (31) of the beam-type sealed pipeline connection assembly (9).

7. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The loop-shaped fixing block (12) has an axisymmetric structure. The loop-shaped fixing block (12) has a loop-shaped hole (34) machined in the middle. The loop-shaped hole (34) has a through hole one (35) and a through hole two (37) at its upper and lower ends, respectively. The diameter of the through hole one (35) is larger than that of the through hole two (37). The through hole one (35) is clearance-fitted with the stepped shaft one (26) of the Z-shaped pressure valve block (7). The through hole two (37) is adapted to the stepped shaft three (28) and the fixing nut.

8. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 5, characterized in that: The fine-tuning nut (13) is a rotating axisymmetric structure. The fine-tuning nut (13) has 6 blind holes (38) evenly machined on its circumference. The blind holes (38) are used to fit a hex wrench. The fine-tuning nut (13) has a threaded hole five (39) machined in the middle. The threaded hole five (39) meshes with the external thread of the stepped shaft two (27) of the Z-shaped pressure valve block (7). The stepped shaft two (27) is threadedly engaged with the threaded hole five (39) of the fine-tuning nut (13). The stepped shaft three (28) is fixed to the through hole two (37) of the U-shaped fixing block (12) by a nut.

9. The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to claim 1, characterized in that: The adjusting base plate (14) has an axisymmetric structure. The upper end face of the adjusting base plate (14) is machined with a countersunk through hole (40). The countersunk through hole (40) is fixed to the threaded hole (19) of the sliding base (3) by bolts. The end face of the adjusting base plate (14) is provided with a U-shaped groove (41) and a U-shaped groove (42). The hexagonal head of the hexagonal bolt is placed in the U-shaped groove (42). The U-shaped groove (41) restricts the bolt from moving along the axis. The bolt shank passes through the U-shaped groove (41) and is threadedly connected to the threaded hole (22) on the side wall of the concave support seat (6).

10. A method for high-temperature bending fatigue testing of a beam-type sealed pipeline connection assembly, characterized in that: The high-temperature bending fatigue testing device for a beam-type sealed pipeline connection assembly according to any one of claims 1-9 further includes the following steps: Step 1: When assembling the test piece, first insert the stainless steel wire (33) into the threading hole of the threading nut (30), and use a special rolling tool and equipment to squeeze the pipe (32) into the groove of the female connector (31) to form a beam-type sealed pipeline connection assembly (9). Connect the first adapter (8) and the second adapter (10) to both ends of the beam-type sealed pipeline connection assembly (9) respectively, and use the 8.5° inner oblique cone surface of the two to fit with the lip sealing surface of the female connector (31) to achieve sealing. Step 2: During tooling installation and debugging, according to the test piece specifications, move the sliding base 3 along the linear guide rail 1 2, adjust it to the appropriate installation length, and then fix it with countersunk bolts; move the concave support 6 along the linear guide rail 2 4, so that its semi-circular keyway 21 and the semi-circular shaft 230 of the Z-shaped pressure valve block 7 are fitted together to complete the limit; pass the upper end of the Z-shaped pressure valve block 7 through the through hole 1 35 of the U-shaped fixing block 12 and the threaded hole 5 39 of the fine-adjusting nut 13 in sequence, and fix the U-shaped fixing block 12 with the nut on the stepped shaft 3 28; connect the beam-type sealing pipeline connection assembly 9 to the self-aligning ball bearing 11 on the side wall of the high temperature comprehensive test chamber 1 via the adapter tool 2 10; connect the other end of the Z-shaped pressure valve block 7 to the pressure source pipeline. Step 3: When initial stress and strain adjustment is required, attach strain gauges 5mm away from the test end on the beam-type sealed pipe connection assembly (9). Calculate the target bending stress based on the tensile strength and elastic modulus of the pipe (32). Adjust the horizontal stress and strain by rotating the bolts on the base plate (14) to drive the concave support seat (6) to move back and forth. Use a hexagonal wrench to insert into the blind hole (38) of the fine-tuning nut (13) and rotate it to drive the Z-shaped pressure valve block (7) to move up and down to adjust the vertical stress and strain. Complete the initial stress and strain calibration by adjusting the displacement offset of the self-aligning ball bearing (11). Step 4: When it is necessary to set the experimental parameters, close the high temperature comprehensive test chamber (1), start the equipment and set the test temperature to 200℃, keep it sealed until the temperature inside the chamber is stable; introduce the pressure medium into the Z-shaped through hole of the Z-shaped pressure valve block (7) through the pressure source, adjust the test pressure to 35MPa and keep it stable; Step 5: When the high temperature bending fatigue test is carried out, start the transmission shaft connected by the self-aligning ball bearing (11) to provide rotational bending power, and carry out at least 10^7 high temperature rotational bending fatigue tests according to the test method in 3.3 of HB6442; during the test, the sealing performance and structural integrity of the test piece are monitored in real time through the failure monitoring function of the high temperature comprehensive test chamber (1); Step 6: End of test and data recording: After the test reaches the preset number of times or the test piece fails, stop the power source and heat source, and wait for the high temperature comprehensive test chamber (1) to cool naturally to room temperature before releasing the pressure; disassemble the test piece and each tooling component, record the number of tests, failure mode, stress-strain change curve and other data, and complete the test report.

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