A single degree of freedom servo-based aircraft strength test restraint device
By employing a single-degree-of-freedom servo constraint device in aircraft strength testing, the problem of lateral displacement of the landing gear caused by wing deformation was solved, enabling servo deformation of the landing gear and rapid replacement of force sensors, thereby improving the accuracy and efficiency of the test.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA AIRPLANT STRENGTH RES INST
- Filing Date
- 2023-03-30
- Publication Date
- 2026-05-19
AI Technical Summary
In traditional aircraft structural strength tests, the deformation caused by the vertical load on the wing leads to a large lateral displacement of the main landing gear wheel center. Traditional rigid constraints limit the wing deformation and cannot realize the actual load.
A single-degree-of-freedom servo constraint device is adopted. By applying servo constraints at the landing gear wheel center, the aircraft attitude is adjusted to achieve servo deformation of the landing gear, providing vertical constraints and lateral degrees of freedom.
The system provides necessary vertical constraints within the landing gear deformation range to ensure the authenticity of the landing gear load, while also featuring a quick-change function for the force sensor, thus improving the accuracy and efficiency of the test.
Smart Images
Figure CN116238708B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of aircraft strength testing technology, and specifically relates to an aircraft strength testing constraint device based on single-degree-of-freedom servo. Background Technology
[0002] In aircraft structural strength tests, test specimens are typically constrained by six-degree-of-freedom statically determinate supports. The support locations are usually selected from non-tested parts of the test aircraft with high stiffness, such as the landing gear and engines. In a general aviation aircraft, the main landing gear is mounted on the wing. During the strength test, the vertical load on the wing caused wing deformation, resulting in significant lateral displacement of the main landing gear wheel center. Traditional rigid constraints on the landing gear limited the wing deformation. Summary of the Invention
[0003] To address the aforementioned technical problems, this application proposes an aircraft strength test constraint device based on single-degree-of-freedom servo control. By employing a servo constraint method at the landing gear wheel center, the aircraft attitude is adjusted servo-adjusted according to the applied load during the test, thereby achieving servo constraint of the landing gear.
[0004] The single-degree-of-freedom servo-based aircraft strength test constraint device provided in this application is used to vertically constrain landing gear dummy wheels and provide lateral degrees of freedom. The constraint device includes a support platform, a landing gear servo support, a force sensor, a limiting bushing, and a single-degree-of-freedom slider. The support platform is fixed on the test site track and supports the landing gear servo support through the force sensor. Two slide rails are fixed on both sides above the landing gear servo support, and a single-degree-of-freedom slider is slidably mounted on each slide rail. The two single-degree-of-freedom sliders are respectively connected to the two bottom support ends of the landing gear dummy wheel. The limiting bushing is detachably connected to the slide rail. When the limiting bushing is located on the slide rail, the single-degree-of-freedom slider is restricted from sliding.
[0005] Preferably, the single-degree-of-freedom slider is fixedly connected to a slider double-ear adapter, which has double ears that are adapted to connect to the single ear at the bottom support end of the landing gear dummy wheel.
[0006] Preferably, the slide rail is fixedly connected to support plates at both ends.
[0007] Preferably, the slide rail is fixed to the landing gear follower support by a slide rail support, and the slide rail support is respectively connected to the slide rail and the landing gear follower support by bolts.
[0008] Preferably, the force sensor has a force sensor connector threaded to each end. The force sensor connector located above the force sensor is connected to the landing gear follower support by bolts, and the force sensor connector located below the force sensor is connected to the support frame by bolts.
[0009] Preferably, the restraint device further includes a lifting protection device, which includes an internal threaded component and an external threaded component. The internal threaded component is fixed to the support frame, and the internal threaded component is threadedly connected to the external threaded component. The entire device is placed on both sides of the force sensor and located in the gap between the support frame and the landing gear follower support. Rotating the external threaded component can cause the top of the external threaded component to leave or contact the lower surface of the landing gear follower support.
[0010] Preferably, the restraint device further includes a downward protection device, which includes a fixed pull plate, a tightening screw sleeve, and a protective double ear seat. The fixed pull plate is hinged to the side of the support frame, the protective double ear seat is hinged to the lower surface of the landing gear follower support, and the tightening screw sleeve is hinged between the fixed pull plate and the protective double ear seat. The length of the tightening screw sleeve is adjusted by rotating the screw sleeve located in the middle.
[0011] This application realizes single-degree-of-freedom follow-up when the landing gear is used as a constraint. The landing gear can provide necessary vertical constraints within a certain deformation range, ensuring the actual load on the constraint parts of the landing gear during the test loading process. It also has the function of quick replacement of force sensors. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the constraint device structure of a preferred embodiment of the single-degree-of-freedom servo-based aircraft strength test constraint device of this application.
[0013] Figure 2 This is a schematic diagram of the connection structure between the landing gear follower support and the single-degree-of-freedom slider.
[0014] Figure 3 This is a diagram illustrating the replacement of the force sensor.
[0015] Among them, 1-support frame, 2-force sensor connector, 3-fixed pull plate, 4-tightening screw sleeve, 5-protective double ear seat, 6-landing gear follower support, 7-slide rail support, 8-support blocking plate, 9-force sensor, 10-limit bushing, 11-slider double ear adapter, 12-internal threaded part, 13-external threaded part, 14-single degree of freedom slider, 15-slide rail, 16-landing gear dummy wheel. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0017] This application provides a single-degree-of-freedom servo-based aircraft strength testing constraint device for vertically constraining and providing lateral degrees of freedom for a landing gear dummy wheel 16. The constraint device includes a support platform 1, a landing gear servo support 6, a force sensor 9, a limiting bushing 10, and a single-degree-of-freedom slider 14. Figure 1 and Figure 2 As shown, the support frame 1 is fixed on the test site track and the landing gear follower support 6 is supported by the force sensor 9. Two slide rails 15 are fixed on both sides above the landing gear follower support 6. A single-degree-of-freedom slider 14 is slidably arranged on each slide rail 15. The two single-degree-of-freedom sliders 14 are respectively connected to the two bottom support ends of the landing gear dummy wheel 16. The limiting bushing 10 is detachably connected to the slide rail 15. When the limiting bushing 10 is on the slide rail 15, the single-degree-of-freedom slider 14 is restricted from sliding.
[0018] In this embodiment, the servo constraint system consists of two sets of single-degree-of-freedom sliders 14, slide rails 15, and landing gear dummy wheels 16, assembled with the landing gear servo support 6 as a whole. It is fixed to the support frame 1 by force sensors 9. During full-scale aircraft testing, the limit bushings 10 are not installed on the slide rails 15 of the servo constraint system, allowing for servo deformation of the landing gear, i.e., deformation perpendicular to the ground plane caused by external loads during the test. Figure 1 When the plane of the paper shows a deformation trend, the landing gear dummy wheel 16 slides freely in one direction with the slider and deforms accordingly. During the component test, a limit bushing 10 is installed on the slide rail 15 of the follow-up constraint system to fix the landing gear dummy wheel 16 in the initial position to ensure that the aircraft attitude is correct.
[0019] In some alternative embodiments, the single-degree-of-freedom slider 14 is fixedly connected to a slider double-ear adapter 11, which has double ears that are adapted to connect to the single ear at the bottom support end of the landing gear dummy wheel 16. In this embodiment, the slider double-ear adapter 11 is bolted to the single-degree-of-freedom slider 14, and the two ends of the landing gear dummy wheel 16 are connected together by bolts to the left and right sides of the slider double-ear adapter 11, forming a complete single-degree-of-freedom servo system.
[0020] In some alternative embodiments, support plates 8 are fixedly connected to both ends of the slide rail 15. The support plates 8 prevent the single-degree-of-freedom slider 14 from sliding out of the slide rail 15. On the other hand, after setting the support plates 8, the limiting bushing 10 can be set between the single-degree-of-freedom slider 14 and the support plates 8, thereby simplifying the installation method of the limiting bushing 10.
[0021] In some alternative embodiments, the slide rail 15 is fixed to the landing gear follower support 6 by a slide rail support 7, and the slide rail support 7 is bolted to both the slide rail 15 and the landing gear follower support 6. In this embodiment, the slide rail 15 has an Ω-shaped cross-section, with a cylindrical track at the upper end and a plate structure at the lower end, which allows it to be connected to the slide rail support 7 by bolts.
[0022] In some optional embodiments, the force sensor 9 has a force sensor connector 2 threadedly connected to each end. The force sensor connector 2 located above the force sensor 9 is bolted to the landing gear follower support 6, and the force sensor connector 2 located below the force sensor 9 is bolted to the support frame 1. In this embodiment, one end of the force sensor connector 2 is disc-shaped, and the other end is a cylindrical structure with external threads. The disc end of the lower force sensor connector 2 is bolted to the upper surface of the support frame 1, and the threaded other end is directly threaded into the lower cylinder of the force sensor 9. Correspondingly, the disc end of the upper force sensor connector 2 is bolted to the lower surface of the landing gear follower support 6, and the threaded other end is directly threaded into the upper cylinder of the force sensor 9.
[0023] In some alternative embodiments, the restraint device further includes a lifting protection device, which includes an internal threaded component 12 and an external threaded component 13. The internal threaded component 12 is fixed to the support frame 1, and the internal threaded component 12 and the external threaded component 13 are threadedly connected. The entire device is placed on both sides of the force sensor 9 and is located in the gap between the support frame 1 and the landing gear follower support 6. Rotating the external threaded component 13 can cause the top of the external threaded component 13 to leave or contact the lower surface of the landing gear follower support 6.
[0024] In this embodiment, by rotating the external threaded part 13, the external threaded part 13 lifts the landing gear follower support 6, thereby allowing the force sensor 9 to be replaced.
[0025] In some alternative embodiments, the restraint device further includes a downward protection device, which includes a fixed pull plate 3, a tightening screw sleeve 4, and a protective double ear seat 5. The fixed pull plate 3 is hinged to the side of the support frame 1, the protective double ear seat 5 is hinged to the lower surface of the landing gear follower support 6, and the tightening screw sleeve 4 is hinged between the fixed pull plate 3 and the protective double ear seat 5. The length of the tightening screw sleeve 4 can be adjusted by rotating the screw sleeve located in the middle.
[0026] In this embodiment, the downward protection device is usually used in conjunction with the upward protection device, and the two are used together, such as... Figure 3 As shown, when force sensor 2 needs to be replaced, rotate the internal thread 12 of the lifting protection device outward to the lower surface of the landing gear follower support 6, and simultaneously tighten the loosening and tightening sleeving 5 of the downward protection device. At this point, the bolts on the connectors at both ends of the force sensor 9 can be removed. Then, fine-tune the lengths of the lifting and downward protection devices until there is approximately a 2mm gap between the force sensor connector 2 and the landing gear follower support 6. Finally, pull out the force sensor 9 along with connector 2 as a whole. Similarly, follow the reverse steps to install the expired force sensor 2 in the designated position, thereby ensuring the safety of the testing machine.
[0027] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A single-degree-of-freedom servo-based aircraft strength test constraint device, used to provide vertical constraint and lateral degree of freedom for landing gear dummy wheels (16), characterized in that, The constraint device includes a support frame (1), a landing gear follower support (6), a force sensor (9), a limit bushing (10), and a single-degree-of-freedom slider (14); Among them, the support frame (1) is fixed on the test site track and the landing gear follower support (6) is supported by the force sensor (9). Two slide rails (15) are fixed on both sides above the landing gear follower support (6). A single-degree-of-freedom slider (14) is slidably set on each slide rail (15). The two single-degree-of-freedom sliders (14) are respectively connected to the two bottom support ends of the landing gear dummy wheel (16). The limiting bushing (10) is detachably connected to the slide rail (15). When the limiting bushing (10) is on the slide rail (15), the single-degree-of-freedom slider (14) is restricted from sliding.
2. The aircraft strength test constraint device based on single-degree-of-freedom servo as described in claim 1, characterized in that, The single-degree-of-freedom slider (14) is fixedly connected to a slider double-ear adapter (11), which has double ears that are adapted to connect to the single ear at the bottom support end of the landing gear dummy wheel (16).
3. The aircraft strength test constraint device based on single-degree-of-freedom servo as described in claim 1, characterized in that, The slide rail (15) is fixedly connected to support plates (8) at both ends.
4. The aircraft strength test constraint device based on single-degree-of-freedom servo as described in claim 1, characterized in that, The slide rail (15) is fixed to the landing gear follower support (6) by the slide rail support (7), and the slide rail support (7) is connected to the slide rail (15) and the landing gear follower support (6) by bolts.
5. The aircraft strength test constraint device based on single-degree-of-freedom servo as described in claim 1, characterized in that, The force sensor (9) is threaded to a force sensor connector (2) at both ends. The force sensor connector (2) located above the force sensor (9) is bolted to the landing gear follower support (6), and the force sensor connector (2) located below the force sensor (9) is bolted to the support frame (1).
6. The aircraft strength test constraint device based on single-degree-of-freedom servo as described in claim 1, characterized in that, The restraint device also includes a lifting protection device, which includes an internal threaded part (12) and an external threaded part (13). The internal threaded part (12) is fixed on the support frame (1). The internal threaded part (12) and the external threaded part (13) are threadedly connected and are placed on both sides of the force sensor (9) and located in the gap between the support frame (1) and the landing gear follower support (6). Rotating the external threaded part (13) can make the top of the external threaded part (13) leave or contact the lower surface of the landing gear follower support (6).
7. The aircraft strength test constraint device based on single-degree-of-freedom servo as described in claim 6, characterized in that, The restraint device also includes a downward protection device, which includes a fixed pull plate (3), a tightening screw sleeve (4), and a protective double ear seat (5). The fixed pull plate (3) is hinged to the side of the support frame (1), the protective double ear seat (5) is hinged to the lower surface of the landing gear follower support (6), and the tightening screw sleeve (4) is hinged between the fixed pull plate (3) and the protective double ear seat (5). The length of the tightening screw sleeve (4) can be adjusted by rotating the screw sleeve located in the middle.