Drop test trim adjustment device and method

Abstract

The application provides a drop test balancing adjustment device and method, the device comprises: an extension arm 1, a longitudinal balancing rod 2, a main frame 3, a vertical balancing rod 4, a transverse balancing rod 5, a gravity center tracking adjustment beam 6, a balancing block 7, a mounting interface 8, a transverse adjustment support 9, a guide limiting plate 10, a movable hanging lug 11, an adjustment screw rod 12, a rotating handle 13; the application can be used to realize the dynamic strength and performance examination of the landing gear structure, is mainly related to the tracking adjustment of the drop release hanging point gravity center position, the decoupling of the counterweight mass, the adjustment of the counterweight position, the gravity center and the moment of inertia parameter balancing and the installation of the test piece, and the accurate examination requirement of the dynamic strength and performance verification of the landing gear structure can be met.

Description

Technical Field

[0001] This application belongs to the field of helicopter landing gear drop test technology, specifically relating to a drop test trim adjustment device and method. Background Technology

[0002] Helicopter landing gear is a typical landing energy-absorbing structure, effectively reducing the landing load and absorbing the vertical kinetic energy generated during the fall, preventing potential structural damage during the crash. In the helicopter field, the quality of landing gear is not only reflected in its strength, but more importantly, in its crucial role in energy absorption and cushioning. As the first-stage energy-absorbing structure during helicopter landing, its energy absorption efficiency, landing load, and reserve power are important indicators for evaluating landing gear performance. In extreme cases, crash tests are necessary to verify the landing gear's maximum energy absorption capacity, accurately determining the survival rate of personnel in the event of an accidental helicopter crash.

[0003] Therefore, accurately evaluating landing gear performance in the laboratory and testing its performance parameters such as power absorption and landing load under various operating conditions is of great significance for the overall design and performance evaluation of helicopters. Currently, when testing tricycle landing gear systems in the laboratory, the reduced mass method is usually used to evaluate a single landing gear system. This method is relatively simple, requiring only the overall release mass parameters to be balanced. However, integral landing gear is more special because it is generally a single structure. Therefore, when evaluating its performance, it is usually necessary to refer to the takeoff weight of the entire aircraft and conduct performance tests on it separately.

[0004] In this situation, it is necessary to consider more physical parameters, mainly including weight, center of gravity, and moment of inertia. Whether these parameters accurately reflect the actual situation will affect the accuracy of the entire test results. Currently, the traditional balancing adjustment device used in laboratory drop tests has a relatively fixed balancing point, discontinuous center of gravity adjustment, and difficult counterweight adjustment. It is only suitable for testing tasks of a single landing gear model. For tests that need to complete multiple test states, this is time-consuming, labor-intensive, inefficient, and difficult to meet current testing requirements.

[0005] Therefore, designing a novel drop test trim adjustment device to overcome the shortcomings of traditional design methods is extremely important for improving the efficiency and quality of landing gear drop tests. Currently available drop test trim adjustment devices mainly focus on weight and center of gravity trim, rarely addressing rotational inertia parameter trim, which clearly cannot meet the requirements of landing gear performance testing. Based on these considerations, the laboratory urgently needs to design a drop test trim adjustment device to meet the requirements for assessing the structural strength and performance of landing gear. Summary of the Invention

[0006] The purpose of this invention is to provide a drop test balancing adjustment device and method, which can be used to assess the dynamic strength and performance of landing gear structures. This mainly involves tracking and adjusting the drop drop attachment point to the center of gravity position, decoupling the counterweight mass, adjusting the counterweight position, balancing the center of gravity and moment of inertia parameters, and installing the test specimen. This can meet the precise assessment requirements for verifying the dynamic strength and performance of landing gear structures.

[0007] This application provides a drop test balancing adjustment device, which includes: an extension arm 1, a longitudinal balancing rod 2, a main frame 3, a vertical balancing rod 4, a transverse balancing rod 5, a center of gravity tracking adjustment beam 6, a balancing block 7, an installation interface 8, a transverse adjustment support 9, a guide limit plate 10, a movable lug 11, an adjustment screw 12, and a rotating handle 13.

[0008] The extension arm 1 is connected to the main frame 3 on the side to assist in balancing the rotational inertia parameters in the pitch direction; the longitudinal balancing rod 2 is adjusted by sliding up and down along the slide groove of the extension arm 1 to track the center of gravity position, and the lateral adjustment and moving balancing block 7 is installed to adjust the rotational inertia and center of gravity; the lower end of the main frame 3 is designed with an installation interface to connect with the landing gear device, and the upper end is designed with a lifting interface to realize the lifting and instantaneous drop of the entire test frame. At the same time, various interfaces are reserved on the main frame for the installation of the extension arm 1, the balancing rod and various sensing devices.

[0009] The vertical balancing rod 4 is adjusted by sliding back and forth along the slide groove on the main frame 3 to track the center of gravity position, and the vertically adjustable balancing block 7 is installed to adjust the rotational inertia and center of gravity. The horizontal balancing rod 5 and the center of gravity tracking and adjusting beam 6 work together to adjust the center of gravity position by sliding up and down and back and forth along the slide groove on the main frame 3, and the vertically and longitudinally adjustable balancing block 7 is installed to adjust the rotational inertia and center of gravity.

[0010] The mounting interface 8 is located below the main frame 3 and is used to install and fix the landing gear device, and to make lateral and longitudinal adjustments in the plane; the lateral adjustment support 9 makes fine adjustments in the lateral direction to track the center of gravity position; the guide limit plate 10 keeps the floating lug 11 in a vertical position; the adjusting screw 12 works in conjunction with the rotating handle 13 to adjust the longitudinal position of the floating lug 11.

[0011] Preferably, the extension arm 1 is fixedly connected to the front and rear ends of the main frame 3 respectively. The extension arm 1 has a narrow slot-shaped through hole designed in the middle position of the vertical beam to install and adjust the vertical position of the longitudinal balancing rod 2.

[0012] Preferably, the main frame 3 is designed with a lifting interface and a test piece installation interface at the top and bottom, respectively. The main frame 3 is also designed with a leveling rod, a center of gravity tracking and adjustment beam 6, and various sensor installation interfaces.

[0013] Preferably, the longitudinal balancing rod 2, the vertical balancing rod 4, and the transverse balancing rod 5 are all fully threaded, and the balancing rods have clamping nuts for pushing the balancing block 7 to move, adjust, and clamp.

[0014] Preferably, the center of gravity tracking adjustment beam 6 has installation interfaces on both ends, which are fixedly connected to the main frame 3, and a narrow slot-shaped through hole in the middle for adjusting the transverse leveling rod 5.

[0015] Preferably, the bottom of the lateral adjustment support 9 is designed with a slotted hole to be fixedly connected to the main frame 3, and the upper plate is designed with a bearing mounting groove to install bearings and adjusting screws 12;

[0016] The guide limit plate 10 has mounting holes at both ends that are fixedly connected to the transverse adjustment support 9, and a narrow slot-shaped hole in the middle.

[0017] Preferably, the lower end of the movable lug 11 is designed with a threaded through hole and a limiting foot, and the upper part is designed with a semi-waist-shaped hole; the adjusting screw 12 has a fully threaded structure and is used in conjunction with the rotating handle 13.

[0018] Secondly, this application also provides a drop test balancing adjustment method, the method comprising the following steps:

[0019] Step 1: Install the longitudinal balancing rod 2 onto the extension arm 1 and connect it to the main frame 3. Connect the center of gravity tracking adjustment beam 6, the vertical balancing rod 4, the transverse balancing rod 5, and the test piece to the main frame 3 respectively.

[0020] Step 2: Assemble the lateral adjustment support 9, guide limit plate 10, movable lug 11, adjustment screw 12, and rotating handle 13 into a whole, and then connect it to the main frame 3;

[0021] Step 3: Use relevant calculation tools to calculate the overall physical parameters of the above components and record the initial mass parameter values;

[0022] Step 4: Based on the target balancing mass parameters required by the experiment, use an optimization algorithm to calculate the balancing position and mass distribution, and then decouple them;

[0023] Step 5: Adjust all balancing rods so that the intersection of their axes coincides with the target mass center position required by the test, and then lock them in place;

[0024] Step 6: Based on the calculated decoupling balancing position and mass distribution, install the balancing block 7 on the balancing rod, adjust it to the corresponding position, and install and tighten it;

[0025] Step 7: Adjust the lateral position of the lateral adjustment support 9 and rotate the handle 13 to adjust the movable lug 11 so that the planar coordinate position of the movable lug 11 coincides with the center of gravity position;

[0026] Step 8: The above steps complete the experimental balancing work under the established experimental conditions.

[0027] This application has the following technical effects:

[0028] This invention pertains to helicopter landing gear drop testing technology, which can be used to assess the dynamic strength and performance of landing gear structures. It primarily involves tracking and adjusting the center of gravity position of the drop attachment point, decoupling the counterweight mass, adjusting the counterweight position, balancing the center of gravity and moment of inertia parameters, and installing the test specimen. This technology can meet the precise assessment requirements for verifying the dynamic strength and performance of landing gear structures. This device can, to a certain extent, overcome the shortcomings of traditional test balancing and adjustment devices, improve test efficiency and quality, and can be flexibly applied to the verification of drop tests on landing gear configurations of the same tonnage, significantly reducing test costs. Attached Figure Description

[0029] Figure 1 Flowchart for balancing and optimizing quality parameters;

[0030] Figure 2 Isometric view of the drop test balancing device;

[0031] Figure 3 An isometric view of a portion of the balancing and adjusting device for a drop test. Detailed Implementation

[0032] This invention focuses on a drop test balancing adjustment device and method, which can be used to assess the dynamic strength and performance of landing gear structures. It mainly involves tracking and adjusting the center of gravity position of the drop anchor point, decoupling the counterweight mass, adjusting the counterweight position, balancing the center of gravity and moment of inertia parameters, and installing the test specimen. This method can meet the precise assessment requirements for verifying the dynamic strength and performance of landing gear structures. This device can improve test efficiency and quality to a certain extent and can be flexibly applied to the verification of drop tests on landing gear configurations of the same tonnage, significantly reducing test costs.

[0033] The drop test balancing adjustment device consists of: an extension arm 1, a longitudinal balancing rod 2, a main frame 3, a vertical balancing rod 4, a transverse balancing rod 5, a center of gravity tracking adjustment beam 6, a balancing block 7, an installation interface 8, a transverse adjustment support 9, a guide limit plate 10, a movable lug 11, an adjustment screw 12, and a rotating handle 13.

[0034] Its functional features: The extension arm 1 is connected to the main frame 3 on the side, mainly assisting in balancing the rotational inertia parameters in the pitch direction; the longitudinal balancing rod 2 can be adjusted up and down along the slide groove of the extension arm 1 to track the center of gravity position, and can be installed and laterally adjusted to move the balancing block 7 to adjust the rotational inertia and center of gravity; the lower end of the main frame 3 is designed with an installation interface to connect with the landing gear device, and the upper end is designed with a lifting interface to realize the lifting and instantaneous drop of the entire test frame. At the same time, various interfaces are reserved on the main frame for the installation of the extension arm 1, the balancing rod, and various sensors and other equipment; the vertical balancing rod 4 can be adjusted back and forth along the slide groove of the main frame 3 to track the center of gravity position, and can also be adjusted... The installation and vertical adjustment of the sliding block 7 enables the adjustment of rotational inertia and center of gravity; the lateral balancing rod 5 and the center of gravity tracking adjustment beam 6 can be adjusted by sliding up and down and back and forth along the slide groove on the main frame 3 to track the center of gravity position, and the installation and vertical and longitudinal adjustment of the sliding block 7 enables the adjustment of rotational inertia and center of gravity; the installation interface 8 is arranged below the main frame 3 for installing and fixing the landing gear device, and can be adjusted laterally and longitudinally in the plane; the lateral adjustment support 9 can be finely adjusted laterally to track the center of gravity position; the guide limit plate 10 keeps the floating lug 11 in a vertical position; the adjusting screw 12 works in conjunction with the rotating handle 13 to adjust the longitudinal position of the floating lug 11.

[0035] Its structural features: the extension arm 1 is fixedly connected to the front and rear ends of the main frame 3 respectively; the extension arm 1 has a narrow slot-shaped through hole designed along the middle position of the vertical beam, which can be used to install and adjust the vertical position of the longitudinal balancing rod 2; the main frame 3 has lifting interfaces and test piece installation interfaces at the upper and lower positions respectively; the main frame 3 also has mounting interfaces for balancing rods, center of gravity tracking adjustment beam 6, and various sensors; the longitudinal balancing rod 2, vertical balancing rod 4, and transverse balancing rod 5 are all fully threaded, and there are clamping nuts on the balancing rods for pushing the smoothing block 7 to move, adjust, and clamp; the center of gravity tracking adjustment beam 6 is designed to be installed and adjusted; the vertical ... The adjusting beam 6 has mounting interfaces on both ends for fixed connection to the main frame 3, and a narrow slotted through hole in the middle for adjusting the lateral balancing rod 5; the lateral adjusting support 9 has a slotted hole at the bottom for fixed connection to the main frame 3, and a bearing mounting groove on the upper plate for mounting bearings and adjusting screw 12; the guide limiting plate 10 has mounting holes at both ends for fixed connection to the lateral adjusting support 9, and a narrow slotted hole in the middle; the floating lug 11 has a threaded through hole and a limiting foot at the lower end, and a semi-waisted hole at the upper part; the adjusting screw 12 has a fully threaded structure and is used in conjunction with the rotating handle 13. All these components together constitute a drop test balancing adjustment device.

[0036] The following reference Figure 1 , Figure 2 , Figure 3 This application will be described in further detail.

[0037] This application provides a drop test balancing adjustment method, which includes the following steps:

[0038] Step 1: Install the longitudinal balancing rod 2 onto the extension arm 1 and connect it to the main frame 3. Connect the center of gravity tracking adjustment beam 6, the vertical balancing rod 4, the transverse balancing rod 5, and the test piece to the main frame 3 respectively.

[0039] Step 2: Assemble the lateral adjustment support 9, guide limit plate 10, movable lug 11, adjustment screw 12, and rotating handle 13 into a whole, and then connect it to the main frame 3;

[0040] Step 3: Use relevant calculation tools to calculate the overall physical parameters of the above components and record the initial mass parameter values;

[0041] in,

[0042] Initial mass: m0;

[0043] Initial center of mass location: x0, y0, z0;

[0044] Initial moment of inertia: I x0 ,I y0 ,I z0 ;

[0045] Step 4: Based on the target balancing mass parameters required by the experiment, use an optimization algorithm to calculate the balancing position and mass distribution, and then decouple them;

[0046] in,

[0047] The target mass parameters for balancing are: m; x, y, z; I x ,I y ,I z ;

[0048] Target mass: m;

[0049] Target quality center location: x, y, z;

[0050] Target moment of inertia: I x ,I y ,I z ;

[0051] The optimization design constraint equations and objective function are as follows:

[0052] Linear constraints:

[0053]

[0054] m1+m2=Δm

[0055] Nonlinear constraints:

[0056]

[0057] The optimization parameters mainly include 6 coordinate parameters and 2 mass parameters, namely, balancing position 1: spatial coordinates (x1, y1, z1), balancing mass m1; balancing position 2: spatial coordinates (x2, y2, z2), balancing mass m2.

[0058] Balance quality decoupling:

[0059] The angle between the balancing position and the target center of mass is:

[0060] Balancing position 1: θ x1 ,θ y1 ,θ z1 ;

[0061] Balancing position 2: θ x2 ,θ y2 ,θ z2 ;

[0062] but:

[0063] m x1 =m1·cosθ x1

[0064] m y1 =m1·cosθ y1

[0065] m z1 =m1·cosθ z1

[0066] m x2 =m2·cosθ x2

[0067] m y2 =m2·cosθ y2

[0068] m z2 =m2·cosθ z2

[0069] Where mx1,my1,mz1;mx2,my2,mz2 are the mass distributions after decoupling for coordinate points (x1,y1,z1) and (x2,y2,z2).

[0070] Step 5: Adjust all balancing rods so that the intersection of their axes coincides with the target mass center position required by the test, and then lock them in place;

[0071] Step 6: Based on the calculated decoupling balancing position and mass distribution, install the balancing block 7 on the balancing rod, adjust it to the corresponding position, and install and tighten it;

[0072] Step 7: Adjust the lateral position of the lateral adjustment support 9 and rotate the handle 13 to adjust the movable lug 11 so that the planar coordinate position of the movable lug 11 coincides with the center of gravity position;

[0073] Step 8: The above steps complete the test balancing work under the established test conditions. After installing all the measuring sensors, the test can begin.

[0074] The device of the present invention can maintain the same state on the test piece during the drop test, and can firmly clamp the test piece and ensure the accurate transmission of dynamic force.

[0075] When using this device for testing, the test personnel first need to have a detailed understanding of the initial parameters of the balancing adjustment device, and then combine the device of this invention to perform decoupling work on the balancing position and mass distribution, etc. The balancing adjustment device can simplify the balancing difficulty through decoupling operation, making the balancing result more accurate, thereby achieving a precise assessment of the performance and dynamic strength of the landing gear device.

Claims

1. A drop test trim adjustment device, characterized by, The device comprises: an extension arm (1), a longitudinal trim bar (2), a main frame (3), a vertical trim bar (4), a horizontal trim bar (5), a gravity center tracking adjusting beam (6), a trim block (7), a mounting interface (8), a horizontal adjusting support (9), a guide limiting plate (10), a movable lug (11), an adjusting screw rod (12), a rotating handle (13); Wherein, the extension arm (1) is connected with the main frame (3) on the side surface, and the rotational inertia parameter in the pitch direction is assisted to be balanced; the longitudinal trim bar (2) is adjusted by sliding up and down in the sliding groove of the extension arm (1), tracks the gravity center position, and installs and horizontally adjusts the moving trim block (7), so that the rotational inertia and the gravity center are adjusted; the lower end of the main frame (3) is designed with a mounting interface, the connection with the landing gear device is realized, the upper end is designed with a lifting interface, the lifting and instantaneous dropping of the whole test frame are realized, and meanwhile, various interfaces are reserved on the main frame for the installation of the extension arm (1), the trim bar and various sensing devices. The vertical trim bar (4) is adjusted by sliding forward and backward in the sliding groove of the main frame (3), tracks the gravity center position, and installs and vertically adjusts the moving trim block (7), so that the rotational inertia and the gravity center are adjusted; the horizontal trim bar (5) and the gravity center tracking adjusting beam (6) are cooperated to be adjusted by sliding up and down and forward and backward in the sliding groove of the main frame (3), track the gravity center position, and install and vertically and longitudinally adjust the moving trim block (7), so that the rotational inertia and the gravity center are adjusted. The mounting interface (8) is arranged below the main frame (3) and is used for installing and fixing the landing gear device and adjusting horizontally and longitudinally in the plane; the horizontal adjusting support (9) is finely adjusted horizontally and tracks the gravity center position; the guide limiting plate (10) keeps the movable lug (11) in the vertical posture; the adjusting screw rod (12) is cooperated with the rotating handle (13) to adjust the longitudinal position of the movable lug (11).

2. The apparatus of claim 1, wherein, The extension arm (1) is fixedly connected with the main frame (3) at the front and rear ends, respectively, and a long and narrow slot-shaped through hole is designed in the middle position of the vertical beam inside the extension arm (1), which is used for installing and adjusting the up and down position of the longitudinal trim bar (2).

3. The apparatus of claim 2, wherein, The main frame (3) is designed with a lifting interface and a test piece mounting interface at the upper and lower positions, respectively, and the inside of the main frame (3) is also designed with a trim bar, a gravity center tracking adjusting beam (6) and various sensor mounting interfaces.

4. The apparatus of claim 3, wherein, The longitudinal trim bar (2), the vertical trim bar (4) and the horizontal trim bar (5) are all designed with full threads, and the trim bar is provided with a compression nut for pushing the moving adjustment of the trim block (7) and compression.

5. The apparatus of claim 4, wherein, The gravity center tracking adjusting beam (6) is designed with mounting interfaces at the two end surfaces and is fixedly connected with the main frame (3), and a long and narrow slot-shaped through hole is designed in the middle for adjusting the horizontal trim bar (5).

6. The apparatus of claim 5, wherein, The horizontal adjusting support (9) is designed with a slot-shaped hole at the bottom and is fixedly connected with the main frame (3), and the upper plate is designed with a bearing mounting groove for installing a bearing and an adjusting screw rod (12); The guide limiting plate (10) is designed with mounting holes at the two ends and is fixedly connected with the horizontal adjusting support (9), and a long and narrow slot-shaped hole is designed in the middle.

7. The apparatus of claim 6, wherein, The lower end of the movable lug (11) is designed with a threaded through hole and a limiting foot, and the upper part is designed with a half waist type hole; the adjusting screw rod (12) is a full threaded structure and is connected with the rotating handle (13) for use.

8. A drop test trim adjustment method, characterized by, The method is applied to the drop test trim adjustment device according to any one of claims 1-7, and the method comprises the following steps: Step 1, install the longitudinal trim bar (2) on the extension arm (1) and connect with the main frame (3), connect the gravity center tracking adjustment beam (6), the vertical trim bar (4) and the horizontal trim bar (5) with the main frame (3) respectively, and connect the test piece with the main frame (3) respectively; Step 2, assemble the horizontal adjustment support (9), the guide limiting plate (10), the movable lug (11), the adjusting screw rod (12) and the rotating handle (13) into a whole, and then connect with the main frame (3); Step 3, use relevant calculation tools to calculate the physical parameters of the above components, and record the initial mass parameter values; Step 4, according to the trim target mass parameter required by the test, use the optimization algorithm to calculate the trim position and mass distribution, and then decouple; Step 5, adjust all trim bars so that the intersection of their axes coincides with the target mass center position required by the test, and then lock and fix; Step 6, according to the decoupled trim position and mass distribution calculated in step 5, install the trim block (7) on the trim bar, adjust to the corresponding position, and install and press tightly; Step 7, adjust the horizontal position of the horizontal adjustment support (9) and the rotating handle (13) to adjust the operation of the movable lug (11), so that the plane coordinate position of the movable lug (11) coincides with the gravity center position; Step 8, the above steps complete the test trim work under the test state.

Images