A loading device for a vibration coupling test

Abstract

This invention discloses a loading device for a sway-vibration coupling test, comprising a foundation and support brackets; the bottoms of two support brackets are located at the top of the foundation; the lower ends of the left and right sides of the outer frame are pivotally connected to the upper parts of the two support brackets via swaying shafts; an inner frame is provided inside the outer frame; the test specimen is placed inside the inner frame; the inner frame is used for sliding engagement with the outer frame in the vertical direction; a vibration actuator is provided on the lower side of the bottom plate of the outer frame; the cylinder rod of the vibration actuator is connected to the bottom plate of the inner frame; the vibration actuator is used to drive the inner frame to reciprocate vertically; the left and right ends of the bottom of the outer frame are respectively connected to the upper ends of a swaying actuator; the lower ends of the two swaying actuators are fixed to the foundation. This invention can ensure that the vibration direction of the oil tank remains perpendicular to the main axis of the test specimen (e.g., the oil tank) during swaying, and can simulate the combined working condition of swaying and vibration acting simultaneously, thus improving the accuracy of the test results.

Description

Technical Field

[0001] This invention relates to the field of mechanical environment testing equipment technology, and in particular to a loading device for a vibration coupling test. Background Technology

[0002] During flight, aircraft are affected by factors such as aerodynamic turbulence, landing impact, weapon launch, and engine and hydraulic pump vibration. This causes the fuel inside the onboard fuel tank to slosh and impact, while the tank simultaneously bears sloshing loads along the longitudinal and lateral directions of the aircraft, as well as vibration loads along the hardpoints. To assess the structural integrity and functional reliability of the fuel tank under complex operating conditions, combined sloshing and vibration environmental tests are necessary.

[0003] The aviation industry standard HB 6757-1993, "Requirements for Aircraft Fuel Tank Sloshing and Vibration Tests," clearly stipulates in Clause 4.2.2 that the sloshing and vibration test equipment should be able to generate sinusoidal vibrations at a specified frequency that are always perpendicular to the main axis of the test fuel tank, while the main axis of the test fuel tank should also be able to slosh around the sloshing axis in a pitching or rolling direction. This standard sets forth clear technical requirements for the motion coupling relationship of the sloshing and vibration test equipment.

[0004] However, when using existing traditional testing equipment, the vibration excitation direction changes relative to the main axis of the fuel tank when the fuel tank rotates around the swaying axis. This fails to meet the requirement of "the vibration direction is always perpendicular to the main axis of the fuel tank" in the aviation industry standard HB 6757-1993 "Requirements for Aircraft Fuel Tank Swaying and Vibration Tests", and cannot guarantee that the vibration direction is always perpendicular to the main axis of the fuel tank.

[0005] Furthermore, existing traditional testing equipment cannot simulate the combined working conditions of swaying and vibration acting simultaneously, and ignores the systemic failures that may be induced by the coupling of the two loads, such as structural resonance, loosening of connections, and sealing failure. As a result, the test results deviate significantly from the actual working conditions.

[0006] Therefore, there is an urgent need to design an experimental device that can solve the above technical problems. Summary of the Invention

[0007] The purpose of this invention is to address the technical deficiencies of existing technologies by providing a loading device for vibration coupling tests.

[0008] Therefore, the present invention provides a loading device for a sway coupling test, which includes a foundation, a support, an outer frame, an inner frame, a swaying shaft, a vibration actuator, and a swaying actuator. The bottom of the two support brackets is located at the top of the foundation; The lower ends of the left and right sides of the outer frame are pivotally connected to the upper parts of the two support brackets via a swaying shaft. An inner frame is provided on the inside of the outer frame; The inner side of the inner frame is used to set up the test specimen; The inner frame is used for sliding connection with the outer frame in the vertical direction; A vibration actuator is installed on the underside of the base plate of the outer frame; The cylinder rod of the vibration actuator passes vertically through the pre-drilled through hole on the bottom plate of the outer frame and connects to the bottom plate of the inner frame. Vibration actuator, used to drive the inner frame to reciprocate vertically; The bottom left and right ends of the outer frame are respectively connected to the upper end of a swaying actuator; The lower ends of the two swaying actuators are fixed to the foundation.

[0009] As can be seen from the technical solution provided by the present invention above, compared with the prior art, the present invention provides a loading device for a swaying coupling test, which is scientifically designed and can ensure that the vibration direction of the oil tank is always perpendicular to the main axis of the test piece (e.g., the oil tank) during the swaying process, which has significant practical significance.

[0010] Furthermore, the device of the present invention can simulate a combined working condition of swaying and vibration acting simultaneously, thereby improving the accuracy of test results and significantly reducing the error between test results and actual working conditions.

[0011] After testing, the device of the present invention is a shaking test bench that can simulate the actual installation conditions of the main oil tank and the suspended auxiliary oil tank, and always keep the vibration direction perpendicular to the main axis of the test piece during the shaking process. It can meet the shaking requirements of oil tanks with bottom fixed method, side mounting method (main oil tank) and suspended mounting (auxiliary oil tank). Attached Figure Description

[0012] Figure 1 A schematic diagram of the loading device for a sway coupling test provided by the present invention; Figure 2 This is a front view of a loading device for a sway coupling test provided by the present invention. The view mainly shows the positional layout of the foundation, support, sway shaft, vibration actuator, sway actuator, outer frame, and inner frame. Figure 3 This is a 45° axonometric view of a loading device for a sway coupling test provided by the present invention. This figure mainly shows the three-dimensional perspective of the structure. Figure 4 Structural diagram of the support; Figure 5 This is a structural diagram of the outer frame; Figure 6 This is a structural diagram of the inner frame; Figure 7 This is a structural diagram of the vibration cylinder mounting base; Figure 8A schematic diagram of the first mounting platform and its surrounding structure; Figure 9 A schematic diagram of the second mounting platform and its surrounding structure; In the diagram, 1-foundation, 2-support bracket, 3-outer frame, 4-inner frame, 5-sway axis; 6-Guide mechanism, 7-Vibration actuator, 8-Swaying actuator, 9-Servo controller, 10-Oil source; 11-Suspended auxiliary oil tank (i.e., a suspended auxiliary oil tank), 12-Sitting oil tank (i.e., a sitting oil tank), 13-Suspended mounting interface, 14-Sitting mounting interface, 15-Vibration cylinder mounting base. Detailed Implementation

[0013] 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.

[0014] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0015] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0016] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0017] The technical solution of the present invention will be further described below through specific embodiments. Details not specified in the embodiments are all conventional technologies in the industry.

[0018] See Figures 1 to 9 The present invention provides a loading device for a sway-vibration coupling test, which is used for a combined sway and vibration test of a test piece (such as an aircraft main fuel tank or a suspended auxiliary fuel tank), and can simultaneously perform a combined loading of pitch sway and vertical vibration. The device includes: foundation 1, support base 2, outer frame 3, inner frame 4, swaying shaft 5, guide mechanism 6, vibration actuator 7, swaying actuator 8, servo controller 9, oil source 10, suspended auxiliary oil tank 11, seated oil tank 12, suspended mounting interface (specifically M20 threaded hole) 13 and seated mounting interface (specifically T-slot) 14; The bottom of the two support brackets 2 is located at the top of the foundation 1; The lower ends of the left and right sides of the outer frame 3 are respectively pivotally connected (that is, rotatably connected) to the upper parts of the two support bases 2 through a rocking shaft 5. It should be noted that, in this invention, the outer frame 3 is pivotally connected (i.e., rotatably connected) to the support 2 via the swaying shaft 5, thereby achieving a swinging motion around the swaying axis.

[0019] An inner frame 4 is provided on the inner side of the outer frame 3; The inner side of the inner frame 4 is used to set the test specimen; The inner frame 4 is used for sliding connection with the outer frame 3 in the vertical direction; A vibration actuator 7 is installed on the underside of the base plate of the outer frame 3; After the cylinder rod of the vibration actuator 7 passes vertically through the pre-drilled through hole on the bottom plate of the outer frame 3 (at the center of the bottom plate of the outer frame 3), it connects to the bottom plate (specifically the center) of the inner frame 4. It should be noted that the vibration actuator 7 is used to drive the inner frame 4 to reciprocate vertically. The bottom left and right ends of the outer frame 3 are respectively connected to the upper end (i.e., the cylinder rod end) of a rocking actuator 8; The lower ends of the two swaying actuators 8 are fixed to the foundation 1.

[0020] In this invention, specifically, the servo controller 9 is electrically connected to the vibration actuator 7 and the swaying actuator 8 respectively, for motion control and data acquisition.

[0021] In this invention, specifically, the oil source 10 is connected to the vibration actuator 7 and the swaying actuator 8 through pipelines to provide hydraulic power.

[0022] In this invention, the inner frame 4 is slidably connected to the outer frame 3 through the guide mechanism 6, so that the inner frame 4 can slide vertically along the outer frame 3.

[0023] For specific implementation details, see [link to implementation details]. Figure 5 , Figure 6 The guide mechanism 6 includes: a slider 6-2 and a slide rail 6-1; On the left and right sides of the outer frame 3, there are vertically distributed outer frame support columns; Each outer frame support column has vertically distributed slide rails 6-1 at its upper and lower ends; On the left and right sides of the inner frame 4, there are vertically distributed inner frame support columns; Each inner frame support column has a slider 6-2 at its upper and lower ends, corresponding to each slide rail 6-1, and the slider 6-2 is slidably connected to the slide rail 6-1.

[0024] It should be noted that the inner frame 4 has a slider 6-2 installed on the inner frame support column, which cooperates with the slide rail 6-1 on the outer frame 3 to realize the sliding of the inner frame 4 along the vertical direction of the outer frame 3.

[0025] It should be noted that the outer frame 3 has slide rails 6-1 at both the upper and lower ends of the outer frame support column, which are used to cooperate with the slider 6-2 of the inner frame 4 for installation, so as to realize the sliding of the inner frame 4 along the vertical direction of the outer frame 3.

[0026] It should be noted that the device of the present invention has a load-bearing frame, which is a double-layer frame, including an outer frame 3, an inner frame 4, a support 2, a rocking shaft 5, and a guide mechanism 6. In terms of specific implementation, the outer frame 3 is a gantry frame structure, using 10mm thick and 210mm high square steel as crossbeams, and 12mm thick and 400mm wide square steel as supporting columns, with diagonal braces on both sides of the columns to enhance the frame strength; the internal dimension of the outer frame 3 is 2790mm. 2650mm.

[0027] In practice, the inner frame 4 is a gantry frame structure, located inside the outer frame 3, and is slidably connected to the outer frame 3 by a slider 6-2 installed on the support column.

[0028] For specific implementation details, see [link to implementation details]. Figure 8As shown, the internal height of the inner frame 4 is 2240mm and the width is 2450mm. The first mounting platform 17, measuring 2000mm × 2000mm, is located on the top of the bottom beam (i.e., the base plate) of the inner frame 4 and is used to mount the seated oil tank. The distance between the first mounting platform 17 and the sway axis is 39mm, which meets the requirement of 500mm from the center of gravity of the test specimen to the sway axis. The distance between the first mounting platform of the inner frame 4 and the sway axis is adapted to the position requirements of the center of gravity of the test specimen.

[0029] See Figure 9 As shown, the second mounting platform 18 (with a hanging mounting interface 13) at the bottom of the top beam (i.e., the upper plate) of the inner frame 4 has a dimension of 950mm. 530mm, used for mounting suspended fuel tanks.

[0030] The bottom of the second mounting platform 18 is provided with a hanging mounting interface 13.

[0031] In practice, the beams of the inner frame 4 adopt a grid frame structure to reduce weight while ensuring rigidity and strength.

[0032] In this invention, specifically, the lower ends of the left and right sides of the outer frame 3 are pivotally connected (i.e., rotatably connected) to the upper parts of the left and right sides of the support 2 via a rocking shaft 5. The specific structural design is as follows: On the upper part of the left and right sides of the support 2, a bearing 16 is installed with a hole; A wobbling shaft 5 is provided transversely through the inner side of the inner ring of each bearing 16; The opposite ends of the two swaying shafts 5 are respectively connected to the lower ends of the left and right sides of the outer frame 3 (fixed connection).

[0033] It should be noted that the lower ends of the two side columns (outer frame support columns) of the outer frame 3 are respectively provided with sway shafts 5, which are rotatably connected to the support base 2 through the sway shafts 5 and the high load-bearing and wear-resistant bearings 16.

[0034] It should be noted that the support 2 is fixed on the foundation 1. There are two support 2s, which are respectively set below the two side columns of the outer frame 3. Each support 2 supports the mass of the outer frame 3 and the test piece and other components through the shaking shaft 5 and the bearing 16.

[0035] It should be noted that there are two sway shafts 5, which are respectively located at the lower ends of the columns on both sides of the outer frame 3. Each sway shaft 5 is rotatably connected to the corresponding support 2 through a high-load-bearing and wear-resistant bearing. Each sway shaft 5 is equipped with a small-clearance bearing 16 to prevent excessive bearing clearance from affecting the vibration effect and causing bearing damage.

[0036] In this invention, the cylinder of the vibrating actuator 7 is fixed to the bottom of the outer frame 3.

[0037] In practice, a vibration cylinder fixing seat 15 is provided at the bottom of the outer frame 3; The cylinder of the vibrating actuator 7 is mounted on the vibrating cylinder mounting base 15.

[0038] It should be noted that the bottom of the outer frame 3 is provided with a vibration actuator mounting base (i.e., vibration cylinder fixing base 15), which is used to fix the cylinder of the vibration actuator 7 and bear the vibration reaction force of the actuator.

[0039] In this invention, specifically, the vibration actuator 7 is positioned corresponding to the bottom center position of the outer frame 3; It should be noted that the vibration actuator 7 is used to realize the system vibration function. The vibration actuator 7 includes a hydrostatic support hydraulic cylinder, a displacement sensor and a servo valve. Among them, the hydrostatic support hydraulic cylinder adopts a double rod structure, with a working pressure of 21MPa and a stroke of ±10mm. The hydrostatic support hydraulic cylinder adopts a hydrostatic support form, and its journal liner uses a plastic coating to supplement the hydrostatic chamber. The system continuously supplies oil to the hydrostatic chamber to keep the piston rod and cylinder wall in pure liquid lubrication. This structure enables the vibration actuator 7 to complete almost frictionless linear motion under high load. It has the characteristics of high frequency response, long service life and strong anti-overturning ability. It can withstand a certain lateral force when the center of gravity of the test piece is slightly off-center, and prevent oil leakage caused by seal wear.

[0040] The displacement sensor is an LVDT (linear displacement sensor), built into the piston rod of the vibration actuator 7. It measures the dynamic displacement of the actuator and feeds it back to the servo controller 9. The servo valve is a Moog G792 series electro-hydraulic servo valve with a peak flow rate of 630 L / min. The servo valve is mounted on the vibration actuator 7 and connected to the hydraulic cylinder via a servo valve block. The servo valve controls the flow and pressure of the hydraulic oil according to the commands of the servo controller 9, ensuring its frequency response meets the test frequency requirements.

[0041] It should be noted that vibration actuator 7 is an application of an existing component (servo actuator). Vibration actuators are mainly used to achieve the system's fixed-frequency vibration function. For example, servo actuators (dynamic) can be used from: China Machinery Testing Equipment Co., Ltd. (model: ML-740.100), Shanghai Qunhe Hydraulic Equipment Co., Ltd., and Jinan Kaide Instrument Co., Ltd. (model: KD-740.100), etc. These manufacturers can all provide customized solutions to meet specific requirements. The industry standard name is "servo actuator," which is a mature technology already widely available in the market and will not be elaborated upon further here.

[0042] In this invention, specifically, the two swaying actuators 8 are symmetrically distributed from left to right.

[0043] It should be noted that the upper cylinder rod end of the swaying actuator 8 is connected to the swaying actuator connecting lug (a standard matching structure for existing swaying actuators) on the side edge of the bottom plate of the outer frame 3. The swaying actuator connecting lug is used to connect the cylinder rod of the swaying actuator 8. The lower cylinder end of the swaying actuator 8 is fixed to the foundation 1 (specifically, it can be achieved through a standard single or double lug structure for the cylinder end of the swaying actuator). The swaying actuator 8 is used to drive the outer frame 3 to swing around the swaying axis 5.

[0044] It should be noted that the swaying actuator 8 is used to push the outer frame 3 to sway, realizing the system's swaying function. It includes a servo hydraulic cylinder, a servo valve, and a displacement sensor. Among them, the servo hydraulic cylinder is a double-rod hydrostatic support cylinder with a stroke of 500mm.

[0045] It should be noted that the swaying actuator 8 is an application of an existing component (servo actuator). The swaying actuator is mainly used to realize the swaying function of the system. For example, servo actuators (dynamic) can be used from: China Machinery Test Equipment Co., Ltd. (model: ML-740.100), Shanghai Qunhe Hydraulic Equipment Co., Ltd., and Jinan Kaide Instrument Co., Ltd. (model: KD-740.100), etc. All of these manufacturers can provide customized solutions to meet specific requirements. The industry standard name is "servo actuator," which is a mature technology product already widely used in the market and will not be elaborated further here.

[0046] It should be noted that both the swaying actuator 8 and the vibration actuator 7 are servo actuators (dynamic), but they differ in parameters such as dynamic frequency, actuator stroke, and dynamic force.

[0047] In this invention, the test piece is a seated oil tank 12; The seated oil tank 12 is located on the top surface of the bottom plate of the inner frame 4.

[0048] It should be noted that, in specific implementation, the top surface of the bottom plate of the inner frame 4 is provided with a first mounting platform 17; The top of the first mounting platform 17 is provided with multiple seat mounting interfaces 14 (e.g., T-slots); the seat mounting interfaces 14 are connected to the seated fuel tank 12; the seat mounting interfaces 14 (e.g., T-slots) are used to connect the fuel tank installation fixture originally matched (i.e., included) with the aircraft's seated fuel tank 12, which can adapt to the installation requirements of different models of seated fuel tanks 12. In this invention, the test piece is a suspended auxiliary fuel tank 11; The suspended auxiliary oil tank 11 is installed on the bottom surface of the upper plate of the inner frame 4.

[0049] It should be noted that, in specific implementation, the bottom surface of the upper plate of the inner frame 4 is provided with a second mounting platform 17; The bottom of the second mounting platform 17 is provided with a hanging mounting interface 13 (e.g., an M20 threaded hole). The suspended mounting interface 13 is connected to the suspended auxiliary fuel tank 11. The suspended mounting interface 13 (e.g., an M20 threaded hole) is used to connect the original (i.e., self-contained) fuel tank installation fixture (e.g., the bolt and nut assembly that connects to it) of the aircraft's suspended auxiliary fuel tank 11, thereby meeting the installation requirements of the suspended auxiliary fuel tank 11.

[0050] In this invention, specifically, the oil source 10 utilizes a mature existing servo hydraulic oil source system with a rated pressure of 21 MPa, a peak flow rate of not less than 815 L / min, and a stable output flow rate of not less than 524 L / min. The oil source 10 includes a constant pressure variable displacement piston pump, a motor, an oil tank, a filter, a control valve assembly, a safety valve, a cooler, and pipelines. The oil source 10 has a low-to-high pressure soft-start function and a separate unloading button for rapid pressure and unloading in case of failure.

[0051] It should be noted that in this invention, the oil source 10 (an existing servo hydraulic oil source system) is an application of existing components, mainly used to provide power for the vibration actuator and the swaying actuator, serving as the system's power source. The oil source 10 of this invention utilizes the existing "600L servo hydraulic oil source system," manufactured by Shanghai Qunhe Hydraulic Equipment Co., Ltd., model name: 600L servo hydraulic oil source system. This is a commercially available and mature technology product, and will not be described further here.

[0052] In this invention, specifically, the device of this invention includes a servo control system; The servo control system includes servo controller 9, which has servo control, data acquisition and processing functions; servo controller 9 adopts the NI hardware platform, with a microprocessor and FPGA as the control core, and runs the VxWorks real-time operating system; The servo controller 9 includes a servo control module and a data acquisition module; The servo control module controls the motion of the swaying actuator 8 and the vibration actuator 7 (specifically, it controls the swaying frequency and displacement of the swaying actuator 8, and the vibration frequency and displacement of the vibration actuator 7). Closed-loop control of swaying and vibration is achieved by controlling the output displacements of the two actuators 8 and 7. The servo control module has PID and PIDF control functions, enabling waveform reproduction of sine waves, square waves, triangle waves, logarithmic frequency sweeps, linear frequency sweeps, and external input signals.

[0053] The data acquisition module is electrically connected to the displacement sensor, acceleration sensor, and angle sensor, respectively. It acquires signals from these sensors to obtain vibration displacement, vibration acceleration, and sway angle information, and processes this information in real time (e.g., stores it). The data acquisition module can acquire 1-4 channels of LVDT, potentiometer, or magnetostrictive displacement sensor signals, 1-4 channels of acceleration sensor signals, and 1-2 channels of load sensor or tilt sensor signals.

[0054] It should be noted that both the accelerometer and the angle sensor are mounted on the test specimen (suspended auxiliary oil tank 11 and seated oil tank 12). Both the suspended auxiliary oil tank 11 and the seated oil tank 12 require the installation of accelerometers and angle sensors during testing. The angle and accelerometer sensors are used to monitor whether the angle of the test specimen's sway and the change in velocity per unit time (acceleration) generated by the vibration meet the test technical requirements.

[0055] The suspended auxiliary oil tank 11 and the seated oil tank 12 are equipped with acceleration sensors and angle sensors at different positions. According to the test requirements, they monitor the shaking and vibration values ​​at different positions of the oil tank to verify whether the structure of the oil tank meets the strength and stiffness requirements.

[0056] In terms of specific implementation, the servo controller 9 also has safety protection functions, including vibration displacement over-limit protection, speed over-limit protection, and oil source pressure monitoring protection. The servo controller 9 is used to monitor various collected and control parameters in real time during the control process. When a parameter is detected to be out of limit (for example, vibration displacement is greater than a preset vibration displacement threshold, vibration acceleration is greater than a preset vibration acceleration threshold, or sway angle is greater than a preset sway angle threshold, or the collected oil source pressure is greater than a preset oil source pressure threshold), it can automatically stop (i.e., issue a control command to control the sway actuator 8 and vibration actuator 7 to stop working) or execute a custom safety action.

[0057] It should be noted that the servo controller 9 is an application of existing components. Specifically, a servo control system produced by the Beijing Strength and Environmental Research Institute can be used. This servo control system can realize functions such as hydraulic cylinder servo control, motor rotation control, data acquisition and processing. The data acquisition function can realize real-time acquisition of data from displacement sensors and angle sensors, as well as real-time acquisition of digital signals such as multiple travel limit switches and emergency stop signals. According to the operator's settings, the system can perform real-time safety threshold judgment on the acquired signals and execute actions according to preset trigger conditions. The servo control system is a commercially available and mature technology product, and will not be described in detail here.

[0058] The accompanying software is responsible for the test control and management of the vibration test bench. Developed based on LabVIEW, the software has been customized and optimized for the functions of the vibration test bench, enabling functions such as parameter setting, test logic control, vibration and sway closed-loop control, control effect display, safety monitoring, data storage, and user access management during the test.

[0059] The system has comprehensive user management functions, with three levels of user permissions. Different user levels have different operation permissions to ensure the safety and controllability of experimental parameters and data.

[0060] To better understand the technical solution of the present invention, the working principle of the present invention is explained below.

[0061] 1. When conducting a shaking test, the present invention sends a command signal to the servo valve of the shaking actuator 8 through the servo controller 9 to control the extension and retraction of the shaking actuator 8, thereby pushing the outer frame 3 to rotate around the shaking axis 5, causing the inner frame 4 and the test piece (e.g., a seated oil tank) mounted on the inner frame 4 to swing together, thereby achieving the set shaking angle and shaking frequency.

[0062] II. During vibration testing, the servo controller 9 sends a command signal to the servo valve of the vibration actuator 7 to control the reciprocating motion of the vibration actuator 7. The cylinder rod of the vibration actuator 7 pushes the inner frame 4 to slide vertically along the outer frame 3, causing the test piece to achieve the preset vibration amplitude and frequency. Since the vibration actuator 7 is fixed on the outer frame 3, when the outer frame 3 shakes, the vibration actuator 7 shakes along with it, and its vibration direction always remains fixed relative to the outer frame 3, thereby ensuring that the vibration direction is always perpendicular to the main axis of the test piece.

[0063] III. In the present invention, when conducting a combined shaking and vibration test: the servo controller 9 simultaneously controls the shaking actuator 8 and the vibration actuator 7, so that the two move according to their respective frequencies and displacements, thereby realizing the combined loading of shaking and vibration.

[0064] In summary, the three test modes show that, for this invention, the servo controller 9 is used to control the movement of the swaying actuator 8 and / or the vibration actuator 7, so that the swaying actuator 8 and / or the vibration actuator 7 move according to their respective frequencies and displacements, thereby realizing the loading of swaying load or vibration load, or the combined loading of swaying and vibration.

[0065] To better understand the technical solution of the present invention, the vibration test process of the present invention is described below.

[0066] The servo controller 9 simultaneously sends command signals to the servo valves of the swaying actuator 8 and the vibration actuator 7, causing them to move according to their respective frequencies and displacements. The swaying actuator 8 drives the outer frame 3 and inner frame 4 to sway, while the vibration actuator 7 drives the inner frame 4 to vibrate. The two actions are superimposed to achieve a combined loading of swaying and vibration. The slide rail 6-1 of the guide mechanism 6 cooperates with the slider 6-2. During vibration, the outer frame 3 provides guidance for the inner frame 4 and bears the lateral force generated during vibration, ensuring that the vibration direction of the vibration actuator 7 always coincides with the axis of the piston rod.

[0067] For this invention, a safety protection process can also be implemented: throughout the entire test, the servo controller 9 monitors the signals from the displacement sensor, acceleration sensor, and angle sensor in real time, as well as the pressure signal from the oil source 10. When any parameter exceeds a preset safety threshold, the servo controller 9 automatically executes a safety protection action, which includes, but is not limited to, issuing an alarm signal, stopping the actuator movement, and unloading the oil source pressure, to ensure the safety of the equipment and the test piece.

[0068] Compared with the prior art, the loading device for the vibration coupling test provided by the present invention has the following beneficial effects: 1. Suspended installation and center of gravity adaptation design to realistically simulate the actual working conditions of auxiliary fuel tanks: The design of this invention allows the test piece to be suspended on the inner frame 4, realistically simulating the actual installation state of auxiliary fuel tanks suspended under the wing or fuselage via a hanger. The load transmission path is consistent with the actual working conditions. Simultaneously, by precisely controlling the distance between the mounting platform and the sway axis, it can adapt to the center of gravity position requirements of different fuel tank models, avoiding additional inertial torque caused by center of gravity shift, and improving sway control accuracy and system stability.

[0069] 2. The double-layered frame structure enables vibration direction tracking: The structure of this invention allows the vibration direction to move synchronously with the swaying frame, ensuring that the vibration direction is always perpendicular to the main axis of the test piece. This strictly meets the mandatory requirement of "vibration direction always perpendicular to the main axis of the test fuel tank" in the aviation industry standard HB6757-1993 "Requirements for Aircraft Fuel Tank Swaying and Vibration Tests". Compared to existing technologies, the vibration direction adaptability of this invention is significantly improved, solving the problem that existing equipment cannot simulate real-time vibration direction matching under combined swaying and vibration conditions.

[0070] 3. The hydrostatic support hydraulic cylinder and the guiding mechanism work together to improve the resistance to eccentric loads: The vibration actuator 7 of this invention includes a hydrostatic support hydraulic cylinder. The hydrostatic support technology enables the actuator to complete almost frictionless linear motion under high loads, featuring high frequency response, long life, and strong anti-overturning capability. When the center of gravity of the test piece is slightly eccentric, the hydrostatic support can withstand a certain lateral force, preventing oil leakage due to seal wear. The guiding mechanism further constrains the movement direction of the inner frame, eliminating the influence of the lateral force generated during vibration on the actuator, ensuring that the vibration direction always coincides with the piston rod axis, and improving the dynamic stability and control accuracy of the system under combined loading conditions.

[0071] 4. Closed-loop servo control and multi-parameter safety protection ensure test accuracy and safety: Closed-loop control (acceleration feedback, displacement feedback) guarantees high-precision tracking of vibration and shaking motion, with high waveform reproduction accuracy, meeting the test waveform requirements of standards such as HB6757. Multi-parameter safety protection functions automatically stop the machine or execute custom safety actions when parameters exceed limits, effectively preventing equipment damage and test piece destruction, and ensuring the safety of the test process.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A loading device for a sway coupling test, characterized in that, It includes a foundation (1), a support (2), an outer frame (3), an inner frame (4), a swaying shaft (5), a vibration actuator (7) and a swaying actuator (8), and a servo controller (9); Among them, the bottom of the two support bearings (2) is set on the top of the foundation (1); The lower ends of the left and right sides of the outer frame (3) are respectively pivotally connected to the upper parts of the two support seats (2) through a swaying shaft (5); An inner frame (4) is provided on the inner side of the outer frame (3); The inner side of the inner frame (4) is used to set the test specimen; The inner frame (4) is used to slide and connect with the outer frame (3) in the vertical direction; A vibration actuator (7) is provided on the underside of the bottom plate of the outer frame (3); After the cylinder rod of the vibration actuator (7) passes vertically through the pre-reserved through hole on the bottom plate of the outer frame (3), it is connected to the bottom plate of the inner frame (4). Vibration actuator (7) is used to drive the inner frame (4) to reciprocate vertically; The bottom left and right ends of the outer frame (3) are respectively connected to the upper end of a swaying actuator (8); The lower ends of the two swaying actuators (8) are fixed to the foundation (1); The servo controller (9) is electrically connected to the vibration actuator (7) and the swaying actuator (8), respectively.

2. The loading device for the sway coupling test as described in claim 1, characterized in that, The inner frame (4) is slidably connected to the outer frame (3) through the guide mechanism (6).

3. The loading device for the vibration coupling test as described in claim 2, characterized in that, The guiding mechanism (6) includes: a slider (6-2) and a slide rail (6-1); The outer frame (3) has vertically distributed outer frame support columns on its left and right sides respectively; Each outer frame support column has vertically distributed slide rails (6-1) at its upper and lower ends. The inner frame (4) has vertically distributed inner frame support columns on its left and right sides respectively; At the upper and lower ends of each inner frame support column, there are sliders (6-2) at positions corresponding to each slide rail (6-1), and the sliders (6-2) are slidably connected to the slide rail (6-1).

4. The loading device for the vibration coupling test as described in claim 1, characterized in that... The lower ends of the left and right sides of the outer frame (3) are pivotally connected to the upper parts of the left and right sides of the support (2) via a swaying shaft (5). The specific structural design is as follows: On the upper left and right sides of the support (2), a bearing (16) is installed. Each bearing (16) has a wobbling shaft (5) that runs transversely through the inner side of its inner ring. The opposite ends of the two swaying shafts (5) are connected to the lower ends of the left and right sides of the outer frame (3), respectively.

5. The loading device for the swaying coupling test as described in claim 1, characterized in that, The cylinder of the vibratory actuator (7) is fixed to the bottom of the outer frame (3).

6. The loading device for the vibration coupling test as described in claim 5, characterized in that, The bottom of the outer frame (3) is provided with a vibration cylinder fixing seat (15); The cylinder of the vibrating actuator (7) is mounted on the vibrating cylinder mounting base (15).

7. The loading device for the vibration coupling test as described in claim 1, characterized in that, The vibration actuator (7) is set at the bottom center position of the outer frame (3); The two swaying actuators (8) are symmetrically distributed on the left and right.

8. The loading device for the sway coupling test as described in claim 1, characterized in that, The test piece was a seated fuel tank (12); The seated oil tank (12) is located on the top surface of the bottom plate of the inner frame (4).

9. The loading device for the sway coupling test as described in claim 1, characterized in that, The test piece is a suspended auxiliary fuel tank (11); The suspended auxiliary oil tank (11) is located on the bottom surface of the upper plate of the inner frame (4).

10. The loading device for the sway coupling test as described in any one of claims 1 to 9, characterized in that, The servo controller (9) is used to control the movement of the swaying actuator (8) and / or the vibration actuator (7), so that the swaying actuator (8) and / or the vibration actuator (7) move according to their respective frequencies and displacements, thereby realizing the loading of swaying load or vibration load, or the combined loading of swaying and vibration.

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