A device for testing the bending fatigue of an aircraft conduit connector under complex load

Abstract

The application discloses a kind of simulation under complex load aircraft conduit connector bending fatigue testing device, it is related to fatigue strength detection technical field, its technical scheme includes: including servo motor, coaxality adjusting system, deflection adjusting system, sealing round bar, test piece, pressure sensor, displacement sensor, fixed platform and complex load loading mechanism, complex load loading machine can accurately simulate circumferential load in actual working condition, complex load is applied in the same test process, real restoration complex stress state of conduit connector in aircraft hydraulic system, make test result more close to actual use situation, greatly improve the reliability of test data, simultaneously, by pressure sensor, displacement sensor and position sensor, test result is monitored in real time, avoid abnormal test data or equipment damage due to limit failure, simultaneously set locking device, prevent handle accidental movement during test process and lead to limit failure.

Description

Technical Field

[0001] This invention relates to the field of fatigue strength testing technology, and more specifically to a device for testing the bending fatigue of aircraft duct connectors under simulated complex loads. Background Technology

[0002] In the aviation field, the reliability of aircraft hydraulic systems is directly related to flight safety. As a key component of the hydraulic system, the bending fatigue performance of conduit connectors under complex load environments is a significant factor affecting system stability. Existing bending fatigue testing devices for aircraft hydraulic system conduit connectors often struggle to accurately simulate the complex load environments of actual operating conditions.

[0003] Traditional testing devices typically apply only axial or circumferential loads, failing to simultaneously apply multiple loads. This leads to discrepancies between test results and actual usage scenarios, making it difficult to accurately assess the fatigue life of duct connectors under complex stress conditions. Furthermore, existing devices have shortcomings in load control accuracy, coaxiality adjustment, and deflection compensation, potentially resulting in significant data errors and hindering reliable data analysis for duct connector design optimization. Therefore, there is an urgent need for a bending fatigue testing device for aircraft duct connectors under simulated complex loads, capable of simulating real-world complex loads and improving testing accuracy. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a bending fatigue testing device for aircraft conduit connectors under complex loads. By setting up a complex load loading mechanism, the device utilizes the cooperation of worm gear one and worm wheel one to drive the clamping cylinder to rotate, accurately simulating the circumferential load in actual working conditions. Worm gear two and worm wheel two cooperate to drive the lead screw nut to rotate, acting on the lead screw to generate axial tension, thus simulating the axial load. This allows for the application of complex loads during the same test process, realistically reproducing the complex stress state of the conduit connector in the aircraft hydraulic system, making the test results closer to actual usage conditions, and significantly improving the reliability of the test data.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a device for simulating bending fatigue testing of aircraft duct connectors under complex loads, comprising a servo motor, a coaxiality adjustment system, a deflection adjustment system, a sealing rod, a test piece, and a fixed platform, and further comprising a complex load loading mechanism, wherein the complex load loading mechanism comprises a lifting platform and a clamping cylinder seat, the lifting platform being disposed above the fixed platform, a lead screw being fixedly installed above the lifting platform, the clamping cylinder seat being slidably installed at the upper end of the lifting platform, a clamping cylinder being rotatably installed inside the clamping cylinder seat, the clamping cylinder clamping one end of the test piece, and a worm gear one, a worm wheel one, a worm gear two, and a worm wheel two being rotatably installed inside the clamping cylinder seat, the worm gear one cooperating with the worm wheel one, the worm wheel one being fixedly connected to the clamping cylinder, the worm gear two cooperating with the worm wheel two, a lead screw nut being fixedly installed inside the worm wheel two, the lead screw nut cooperating with the lead screw.

[0006] As a further improvement of the present invention, the complex load loading mechanism further includes an adjustment box, which is fixedly installed on one side of the clamping cylinder seat. A driven shaft one, a driven shaft two, and a drive shaft are rotatably installed parallel to each other inside the adjustment box. The driven shaft one is fixedly connected to a worm gear one, and the driven shaft two is fixedly connected to a worm gear two. Multiple drive wheels are fixedly installed on the drive shaft. A large pulley and a small pulley are rotatably installed on both the driven shaft one and the driven shaft two. Each of the large pulleys and the small pulleys is connected to the corresponding drive wheel via a belt. An adjustment key is slidably installed on both the driven shaft one and the driven shaft two. Each adjustment key is located between the corresponding large pulley and the small pulley. Multiple connecting grooves are provided on the inner surfaces of the large pulleys and the small pulleys. Multiple connecting protrusions that cooperate with the connecting grooves are provided on both sides of the adjustment key.

[0007] As a further improvement of the present invention, the diameter of the large pulley is larger than the diameter of the small pulley, and both the diameter of the large pulley and the diameter of the small pulley are larger than the diameter of the drive wheel.

[0008] As a further improvement of the present invention, both driven shaft one and driven shaft two are provided with sliding grooves, the adjusting key is arranged in a ring, and a sliding protrusion that cooperates with the sliding groove is fixedly installed on the inner wall of the adjusting key.

[0009] As a further improvement of the present invention, two actuating forks are slidably mounted on the adjustment box. A semi-circular ring is fixedly mounted on one end of the actuating fork. The adjustment key has a ring groove in the middle. Each semi-circular ring is fitted into the corresponding ring groove. The other end of the actuating fork passes through the adjustment box to the outside.

[0010] As a further improvement of the present invention, a plurality of telescopic cylinders are fixedly installed on the upper end of the fixed platform, and the telescopic ends of the plurality of telescopic cylinders are fixedly connected to the lower end of the lifting platform.

[0011] As a further improvement of the present invention, the deflection adjustment system is equipped with an anti-rotation mechanism, which includes an outer ring and an inner ring. The outer ring is fixedly connected to the deflection adjustment system, and the inner ring is rotatably installed inside the outer ring. The sealing rod is fixedly installed on the inner ring. Multiple limiting teeth are arranged in a ring array on the outer wall of the middle part of the inner ring. A limiting rod is movably installed on the outer ring, and the limiting rod can act on the limiting teeth to limit the inner ring in one direction.

[0012] As a further improvement of the present invention, the limiting rod passes through the outer ring, the outer ring is provided with a cavity, a limiting plate is slidably installed in the cavity, the limiting plate is fixedly connected to the limiting rod, a spring is provided at the upper end of the limiting plate, the spring is sleeved on the limiting rod, a slope is provided on one side of the lower end of the limiting rod, and the lower end of the limiting rod is located between two corresponding limiting teeth.

[0013] As a further improvement of the present invention, a plurality of elastic wedge blocks are fixedly installed in a ring array at one end of the clamping cylinder, an external thread is provided on the outer wall of one end of the clamping cylinder, a threaded sleeve is fitted on one end of the clamping cylinder, an internal thread that mates with the external thread is provided on the inner wall of the threaded sleeve, and a wedge ring is fixedly installed on the inner wall of the front end of the threaded sleeve.

[0014] The beneficial effects of this invention are:

[0015] 1. By setting up a complex load loading mechanism, the clamping cylinder is driven to rotate by the cooperation of worm gear one and worm wheel one, which can accurately simulate the circumferential load in actual working conditions; worm gear two and worm wheel two cooperate to drive the lead screw nut to rotate, which acts on the lead screw to generate axial tension, thereby simulating the axial load. Thus, complex loads can be applied in the same test process, which can truly restore the complex stress state of the conduit connector in the aircraft hydraulic system, making the test results closer to the actual use situation and greatly improving the reliability of the test data.

[0016] 2. Within the adjustment box, the driven shafts one and two engage with the drive shaft, utilizing the transmission ratio variation created by the diameter difference between the large and small pulleys. Combined with a sliding adjustment key and its engagement with the connecting groove and connecting protrusion, precise switching between coarse and fine adjustment of circumferential and axial loads is achieved. When the adjustment key is connected to the small pulley, the drive shaft rotates for coarse adjustment, meeting rapid loading requirements; when connected to the large pulley, fine adjustment is achieved, adapting to high-precision load control requirements. This graded adjustment mechanism effectively improves the accuracy of load adjustment, thereby enhancing the accuracy of test results.

[0017] 3. By arranging elastic wedge blocks in a ring array at one end of the clamping cylinder, and having external threads on their outer walls to engage with a threaded sleeve with internal threads and a wedge ring, when the front end of the test piece is inserted into the clamping cylinder, the threaded sleeve is rotated to move along the clamping cylinder. The wedge rings clamp and fix the front end of the test piece using the action of the elastic wedge blocks. This method has the advantages of simple structure and convenient operation. The test piece and the clamping cylinder can be quickly fixed without complicated tools. The ring array of elastic wedge blocks can evenly clamp the test piece, ensuring the stability and reliability of the fixation. At the same time, the threaded connection method facilitates installation and disassembly, improving operational efficiency. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural schematic diagram of the aircraft duct connector bending fatigue testing device under complex loads according to the present invention.

[0019] Figure 2 This is a schematic diagram of the complex load loading mechanism of the present invention;

[0020] Figure 3 This is a side view of the complex load loading mechanism of the present invention;

[0021] Figure 4 This is a cross-sectional structural diagram of the clamping sleeve of the present invention;

[0022] Figure 5 This is a schematic diagram of the internal structure of the regulating box of the present invention;

[0023] Figure 6 This is a schematic diagram of the connection structure of the drive shaft of the present invention;

[0024] Figure 7 This is a schematic diagram of the driven shaft one and driven shaft two of the present invention;

[0025] Figure 8 This is a schematic diagram of the structure of the adjustment key of the present invention;

[0026] Figure 9 This is a cross-sectional structural diagram of the anti-rotation mechanism of the present invention;

[0027] Figure 10 for Figure 5 Enlarged view of point A in the middle;

[0028] Figure 11 This is a schematic diagram of the structure of the clamping cylinder without a threaded sleeve at the end of the present invention.

[0029] Reference numerals: 1. Servo motor; 2. Coaxiality adjustment system; 3. Deflection adjustment system; 4. Sealing rod; 5. Test piece; 6. Complex load loading mechanism; 601. Lifting platform; 602. Telescopic cylinder; 603. Clamping sleeve seat; 604. Adjustment box; 605. Lead screw; 606. Clamping sleeve; 6061. Elastic wedge block; 6062. Threaded sleeve; 607. Worm gear one; 608. Worm wheel one; 609. Worm gear two; 610. Worm gear 2; 611, Lead screw nut; 612, Driven shaft 1; 613, Driven shaft 2; 614, Drive shaft; 615, Large pulley; 616, Small pulley; 617, Adjusting key; 618, Actuating fork; 619, Connecting groove; 620, Connecting protrusion; 621, Sliding groove; 622, Sliding protrusion; 623, Drive wheel; 7, Anti-rotation mechanism; 701, Outer ring; 702, Inner ring; 703, Limiting rod; 8, Fixed platform. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The components of the embodiments of this disclosure described and shown herein can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0031] refer to Figures 1 to 4The diagram illustrates a specific embodiment of the aircraft duct connector bending fatigue testing device under simulated complex loads according to the present invention. The device includes a servo motor 1, a coaxiality adjustment system 2, a deflection adjustment system 3, a sealing rod 4, a test piece 5, and a fixed platform 8. Both the coaxiality adjustment system 2 and the deflection adjustment system 3 are mounted on the fixed platform 8. The sealing rod 4 is fitted into the deflection adjustment system 3. A rotating spindle passes through the coaxiality adjustment system 2, with its front end connected to the deflection adjustment system 3 and its rear end connected to the servo motor 1. It also includes a complex load loading mechanism 6, which includes a lifting platform 601 and a clamping sleeve base 603. The lifting platform 601 is disposed above the fixed platform 8, and a lead screw 605 is fixedly installed on the upper part of the lifting platform 601. The clamping sleeve base 603 is slidably installed on the upper end of the lifting platform 601, and a clamping sleeve 606 is rotatably installed inside the clamping sleeve base 603. The clamping sleeve 606 clamps the front end of the test piece 5. A worm gear 607, a worm wheel 608, a worm gear 609, and a worm wheel 610 are also rotatably installed inside the clamping sleeve base 603. The worm gear 607 cooperates with the worm wheel 608, the worm wheel 608 is fixedly connected to the clamping sleeve 606, and the worm gear 609 is connected to the worm wheel 610. In conjunction with 610, a lead screw nut 611 is fixedly installed inside the second worm gear 610. The lead screw nut 611 cooperates with the lead screw 605. By rotating the first worm gear 607, the first worm gear 608 can be driven to rotate, thereby driving the clamping cylinder 606 to rotate, rotating the front end of the test piece 5 to simulate the circumferential load in actual conditions. By rotating the second worm gear 609, the second worm gear 610 can be driven to rotate, and the second worm gear 610 drives the lead screw nut 611 to rotate. The lead screw nut 611 acts on the lead screw 605, generating a pulling force along the axial direction of the test piece 5 on the clamping cylinder seat 603 and the test piece 5, simulating the axial load in actual conditions. Torque and tension detection devices can be set at the connection between the test piece 5 and the clamping cylinder 606 to facilitate control of the load magnitude. Through the above structural settings, the complex loads of the aircraft hydraulic system conduit connectors in actual conditions can be simulated, making the test results more accurate.

[0032] To further enhance the stability of the mechanism's operation, automatic lubrication devices are installed in the meshing areas of worm gear 607 and worm wheel 608, and worm gear 609 and worm wheel 610 in the complex load loading mechanism 6. These lubrication devices include a miniature oil pump, a lubrication circuit, and a pressure sensor. The miniature oil pump delivers lubricating oil to the meshing tooth surfaces at regular intervals and in measured quantities through the lubrication circuit, while the pressure sensor monitors the lubrication pressure in real time, ensuring that the tooth surfaces are always in a good lubrication state, effectively reducing mechanical wear and extending the service life of the mechanism.

[0033] In a further embodiment, the complex load loading mechanism 6 also includes an adjustment box 604, such as... Figures 5-8As shown, the adjusting box 604 is fixedly installed on one side of the clamping cylinder seat 603. A driven shaft 612, a driven shaft 613, and a drive shaft 614 are rotatably mounted parallel to each other inside the adjusting box 604. The driven shaft 612 is fixedly connected to a worm gear 607, and the driven shafts 613 are fixedly connected to each other. Multiple drive wheels 623 are fixedly mounted on the drive shaft 614. Large pulleys 615 are rotatably mounted on both the driven shaft 612 and the driven shaft 613. The large pulley 615 has a larger diameter than the small pulley 616, and each of the large pulleys 615 and small pulleys 616 is connected to the corresponding drive wheel 623 via a belt. Both driven shaft one 612 and driven shaft two 613 are slidably equipped with adjustment keys 617, each of which is located between the corresponding large pulley 615 and small pulley 616. The inner surfaces of both the large pulley 615 and small pulley 616 are provided with multiple connecting... The groove 619 has multiple connecting protrusions 620 on both sides of the adjusting key 617 that mate with the connecting groove 619. By moving the adjusting key 617, three states can be switched: connected to the large pulley 615, connected to the small pulley 616, and not connected to either. When the adjusting key 617 on the driven shaft 612 is connected to the corresponding small pulley 616, rotating the drive shaft 614 can perform coarse adjustment of the circumferential load. When the adjusting key 617 on the driven shaft 612 is connected to the small pulley 616, rotating the drive shaft 614 can perform coarse adjustment of the circumferential load. The drive shaft 614 can be rotated to finely adjust the circumferential load when connected to the large pulley 615. When the adjustment key 617 on the driven shaft 613 is connected to the corresponding small pulley 616 or large pulley 615, the drive shaft 614 can be rotated to coarsely and finely adjust the axial load. Through the above structural settings, the load adjustment is more precise, improving the accuracy of the test results. After the adjustment is completed, the adjustment key 617 is reset. The self-locking function of the worm gear can prevent changes in the load.

[0034] To diversify the power input of the drive shaft 614, a manual adjustment knob and an electric drive interface can be installed at the end of the drive shaft 614. The manual adjustment knob facilitates fine-tuning of parameters on-site by the operator, while the electric drive interface can connect to an external servo motor or stepper motor to achieve automated load adjustment through a control system, meeting the needs of different testing scenarios. Meanwhile, scale markings and pointers are provided on the inner wall of the adjustment box 604 to clearly display the current connection status of the adjustment key 617 and the load adjustment level, improving operational convenience.

[0035] The diameters of the large pulley 615 and the small pulley 616 are both larger than the diameter of the drive wheel 623. The angular velocity of the drive shaft 614 is always greater than that of the driven shaft 612 and the driven shaft 613, further improving the adjustment accuracy. Furthermore, the belt drive system uses a toothed belt. Compared to traditional flat belts, toothed belts have advantages such as high transmission accuracy and strong anti-slip performance, ensuring synchronous transmission between the drive wheel 623 and the pulleys and avoiding load adjustment errors caused by belt slippage.

[0036] Both driven shaft 1 612 and driven shaft 2 613 are provided with sliding grooves 621. The adjusting key 617 is arranged in a ring shape. A sliding protrusion 622 that cooperates with the sliding groove 621 is fixedly installed on the inner wall of the adjusting key 617. The adjusting key 617 can only slide along driven shaft 1 612 or driven shaft 2 613. Two toggle forks 618 are slidably installed on the adjusting box 604. A semi-circular ring is fixedly installed at one end of the toggle fork 618. The adjusting key 617 has an annular groove in the middle. Each semi-circular ring is fitted into the corresponding annular groove. The other end of the toggle fork 618 passes through the adjusting box 604 to the outside, which facilitates the movement of the adjusting key 617 by the toggle fork 618 without affecting the rotation of the adjusting key 617. To enhance the feel and feedback of the toggle operation, the exposed end of the toggle fork 618 is provided with an anti-slip texture, and limit grooves are provided on the surface of the adjustment box 604 corresponding to the coarse adjustment, fine adjustment and reset positions. When the adjustment key 617 is moved to a specific position, the toggle fork 618 will be embedded in the limit groove, providing clear tactile feedback for position switching and avoiding accidental operation.

[0037] In a further embodiment, a plurality of telescopic cylinders 602 are fixedly installed on the upper end of the fixed platform 8. The telescopic ends of the plurality of telescopic cylinders 602 are all fixedly connected to the lower end of the lifting platform 601, facilitating the lifting of the lifting platform 601 to change the height of the clamping cylinder 606 and to align the test piece 5. To improve the automation and accuracy of the alignment process, the telescopic cylinders 602 are electro-hydraulic servo cylinders, equipped with high-precision displacement sensors, which can monitor and adjust the height of the lifting platform 601 in real time through the control system. At the same time, a guide mechanism consisting of guide columns and linear bearings is set between the fixed platform 8 and the lifting platform 601 to ensure that the lifting process is smooth and without shaking, effectively improving the reliability of the alignment operation.

[0038] In a further embodiment, the deflection adjustment system 3 is equipped with an anti-rotation mechanism 7, such as... Figure 9As shown, the anti-rotation mechanism 7 includes an outer ring 701 and an inner ring 702. The outer ring 701 is fixedly connected to the deflection adjustment system 3. The inner ring 702 is rotatably installed inside the outer ring 701. The sealing rod 4 is fixedly installed on the inner ring 702. Multiple limiting teeth are arranged in a ring array on the outer wall of the middle part of the inner ring 702. A limiting rod 703 is movably installed on the outer ring 701. The limiting rod 703 can act on the limiting teeth to limit the inner ring 702 in one direction. When simulating circumferential load, the clamping cylinder 606 drives the front end of the test piece 5 to rotate clockwise. The limiting rod 703 limits the inner ring 702 to not rotate clockwise, and the sealing rod 4 does not rotate, thereby ensuring that the rear end of the test piece 5 does not rotate and successfully simulates circumferential load. However, the servo motor 1 can still drive the sealing rod 4 to rotate counterclockwise, applying a torsional force to the rear end of the test piece 5, which does not affect the bending fatigue test.

[0039] To ensure reliable engagement between the limit rod 703 and the limit teeth, the limit rod 703 is made of high-strength alloy steel, and its lower bevel surface is hardened, significantly improving its wear resistance. Simultaneously, a position detection sensor is installed inside the anti-rotation mechanism 7 to monitor the working status of the limit rod 703 in real time. If the limit rod 703 abnormally lifts or fails to engage properly during testing, the sensor immediately issues an alarm and triggers a shutdown protection mechanism, preventing abnormal test data or equipment damage due to limit failure.

[0040] The limiting rod 703 passes through the outer ring 701. The outer ring 701 has a cavity within which a limiting plate is slidably installed. The limiting plate is fixedly connected to the limiting rod 703. A spring is provided at the upper end of the limiting plate and is sleeved on the limiting rod 703. One side of the lower end of the limiting rod 703 has an inclined surface, and the lower end of the limiting rod 703 is positioned between two corresponding limiting teeth. During testing, the limiting rod 703 contacts the inner ring 702 under the force of the spring, unidirectionally limiting the inner ring 702. After the test, pulling the limiting rod 703 upwards releases the limitation on the inner ring 702. To facilitate the operator's release operation, an operating handle is provided on the outside of the outer ring 701. The handle is connected to the upper end of the limiting rod 703 via a connecting rod. Moving the handle up and down allows for convenient raising and lowering of the limiting rod 703. A locking device is also provided on the handle to prevent accidental movement during testing that could cause the limiting to fail.

[0041] In a further embodiment, such as Figure 10 and Figure 11As shown, a plurality of elastic wedge blocks 6061 are fixedly installed in a ring array at one end of the clamping cylinder 606. The outer wall of one end of the clamping cylinder 606 is provided with an external thread. A threaded sleeve 6062 is fitted onto one end of the clamping cylinder 606. The inner wall of the threaded sleeve 6062 is provided with an internal thread that mates with the external thread. A wedge ring is fixedly installed on the inner wall of the front end of the threaded sleeve 6062. The front end of the test piece 5 is inserted into the clamping cylinder 606. The threaded sleeve 6062 is fitted onto the end of the clamping cylinder 606 and rotated. The threaded sleeve 6062 moves along the clamping cylinder 606. The wedge ring acts on the elastic wedge blocks 6061. The elastic wedge blocks 6061 clamp the front end of the test piece 5, thus completing the fixation of the test piece 5 and the clamping cylinder 606. The structure is simple and easy to operate.

[0042] To accommodate test pieces 5 with different outer diameters, the elastic wedge block 6061 adopts a replaceable design, with multiple sets of wedge blocks of different angles and sizes available according to the specifications of the test piece 5. Simultaneously, anti-slip textures are provided on the clamping surface of the elastic wedge block 6061 to increase friction with the surface of the test piece 5, ensuring that the test piece 5 does not slip axially or circumferentially during clamping. Furthermore, an annular groove is provided on the outer side of the threaded sleeve 6062, facilitating rotation by operators using specialized tools or by hand, improving clamping efficiency.

[0043] To further improve the functionality of the testing device, a safety guardrail made of transparent acrylic material is installed around the fixed platform 8. This guardrail does not obstruct the operator's observation of the testing process and effectively prevents the test piece 5 from accidentally flying out and causing a safety accident. A torque sensor is installed at the connection between the servo motor 1 and the rotating spindle to monitor the torsional torque applied at the rear end in real time. This forms a two-way monitoring system with the torque detection device of the complex load loading mechanism 6 at the front end, ensuring the accuracy and completeness of the load data during the test. Simultaneously, a data acquisition module is integrated into the device's control system, which can record parameters such as load, displacement, and time during the test in real time and generate graphs and charts to facilitate subsequent data analysis and test report generation.

[0044] Finally, it should be noted that the above-described embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure. Such modifications, changes, 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 this disclosure, and should all be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. A device for simulating bending fatigue testing of aircraft duct connectors under complex loads, comprising a servo motor (1), a coaxiality adjustment system (2), a deflection adjustment system (3), a sealing rod (4), a test piece (5), a pressure sensor, a displacement sensor, and a fixed platform (8), characterized in that: It also includes a complex load loading mechanism (6), which includes a lifting platform (601) and a clamping sleeve seat (603). The lifting platform (601) is located above the fixed platform (8), and a lead screw (605) is fixedly installed above the lifting platform (601). The clamping sleeve seat (603) is slidably installed on the upper end of the lifting platform (601), and a clamping sleeve (606) is rotatably installed inside the clamping sleeve seat (603). The clamping sleeve (606) clamps one end of the test piece (5). The clamping device includes a worm gear 1 (607), a worm wheel 1 (608), a worm gear 2 (609), and a worm wheel 2 (610) rotatably mounted inside the clamping cylinder (603). The worm gear 1 (607) cooperates with the worm wheel 1 (608), the worm wheel 1 (608) is fixedly connected to the clamping cylinder (606), the worm gear 2 (609) cooperates with the worm wheel 2 (610), and a lead screw nut (611) is fixedly mounted inside the worm wheel 2 (610). The lead screw nut (611) cooperates with the lead screw (605). The complex load loading mechanism (6) also includes an adjustment box (604), which is fixedly installed on one side of the clamping cylinder seat (603). A driven shaft one (612), a driven shaft two (613), and a drive shaft (614) are rotatably mounted parallel to each other inside the adjustment box (604). The driven shaft one (612) is fixedly connected to the worm gear one (607), and the driven shaft two (613) is fixedly connected to the worm gear two (609). Multiple drive wheels (623) are fixedly mounted on the drive shaft (614). Large pulleys (614) are rotatably mounted on both the driven shaft one (612) and the driven shaft two (613). 5) and small pulley (616), each of the large pulleys (615) and small pulleys (616) is connected to the corresponding drive wheel (623) by a belt. Both driven shaft one (612) and driven shaft two (613) are slidably mounted with adjustment keys (617). Each of the adjustment keys (617) is located between the corresponding large pulley (615) and small pulley (616). The inner surfaces of the large pulleys (615) and small pulleys (616) are provided with multiple connecting grooves (619). Both sides of the adjustment key (617) are provided with multiple connecting protrusions (620) that cooperate with the connecting grooves (619). Two actuating forks (618) are slidably mounted on the adjustment box (604). A semi-circular ring is fixedly mounted on one end of the actuating fork (618). The adjustment key (617) has a ring groove in the middle. Each semi-circular ring is fitted into the corresponding ring groove. The other end of the actuating fork (618) passes through the adjustment box (604) to the outside.

2. The device for simulating bending fatigue testing of aircraft duct connectors under complex loads according to claim 1, characterized in that: The diameter of the large pulley (615) is larger than the diameter of the small pulley (616), and the diameters of both the large pulley (615) and the small pulley (616) are larger than the diameter of the drive wheel (623).

3. The device for simulating bending fatigue testing of aircraft duct connectors under complex loads according to claim 2, characterized in that: Both driven shaft one (612) and driven shaft two (613) are provided with sliding grooves (621), the adjusting key (617) is arranged in a ring, and a sliding protrusion (622) that cooperates with the sliding groove (621) is fixedly installed on the inner wall of the adjusting key (617).

4. The device for simulating bending fatigue testing of aircraft duct connectors under complex loads according to claim 2, characterized in that: Multiple telescopic cylinders (602) are fixedly installed on the upper end of the fixed platform (8), and the telescopic ends of the multiple telescopic cylinders (602) are fixedly connected to the lower end of the lifting platform (601).

5. The device for simulating bending fatigue testing of aircraft duct connectors under complex loads according to claim 2, characterized in that: The deflection adjustment system (3) is equipped with an anti-rotation mechanism (7). The anti-rotation mechanism (7) includes an outer ring (701) and an inner ring (702). The outer ring (701) is fixedly connected to the deflection adjustment system (3). The inner ring (702) is rotatably installed inside the outer ring (701). The sealing rod (4) is fixedly installed on the inner ring (702). Multiple limiting teeth are arranged in a ring array on the outer wall of the middle part of the inner ring (702). A limiting rod (703) is movably installed on the outer ring (701). The limiting rod (703) can act on the limiting teeth to limit the inner ring (702) in one direction.

6. The device for simulating bending fatigue testing of aircraft duct connectors under complex loads according to claim 5, characterized in that: The limiting rod (703) passes through the outer ring (701). The outer ring (701) has a cavity. A limiting plate is slidably installed in the cavity. The limiting plate is fixedly connected to the limiting rod (703). A spring is provided at the upper end of the limiting plate. The spring is sleeved on the limiting rod (703). A slope is provided on one side of the lower end of the limiting rod (703). The lower end of the limiting rod (703) is located between two corresponding limiting teeth.

7. The device for simulating bending fatigue testing of aircraft duct connectors under complex loads according to claim 1, characterized in that: One end of the clamping cylinder (606) is fixedly installed with a plurality of elastic wedge blocks (6061) in a ring array. The outer wall of one end of the clamping cylinder (606) is provided with an external thread. One end of the clamping cylinder (606) is fitted with a threaded sleeve (6062). The inner wall of the threaded sleeve (6062) is provided with an internal thread that mates with the external thread. A wedge ring is fixedly installed on the inner wall of the front end of the threaded sleeve (6062).

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