Falling test balancing adjusting device and method

Abstract

The invention provides a drop test balancing adjusting device and method. The drop test balancing adjusting device comprises an extension support 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 adjusting beam 6, a balancing sliding block 7, a mounting interface 8, a transverse adjusting support 9, a guide limiting plate 10, a moving hanging lug 11, an adjusting lead screw 12 and a rotating handle 13. The device can be used for checking the dynamic strength and performance of the undercarriage structure, mainly relates to tracking adjustment of the gravity center position of a drop putting hanging point, counterweight mass decoupling, counterweight position adjustment, gravity center and rotational inertia parameter balancing, test piece installation and the like, and can meet the requirement for accurate checking of the dynamic strength and performance verification of the undercarriage structure.

Description

Technical Field

[0001] The present application belongs to the technical field of helicopter landing gear drop test, and in particular relates to a drop test trim adjustment device and method. Background Art

[0002] The helicopter landing gear is a typical landing energy-absorbing structure, which can effectively reduce the landing load of the helicopter, absorb the vertical kinetic energy generated during the fall of the fuselage, and avoid potential damage to the helicopter structure at the moment of falling. In the field of helicopters, the quality of the landing gear is not only reflected in its strength, but more importantly, it plays an important role in energy absorption and cushioning. As the first-level energy-absorbing structure at the moment of helicopter landing, its energy absorption efficiency, landing load and reserve power are important indicators for testing the performance of the landing gear. In extreme cases, the landing gear device needs to be subjected to a crash resistance test to test the maximum energy absorption of the landing gear, so as to make an accurate judgment on the survival rate of personnel after an unexpected helicopter crash.

[0003] Therefore, accurately assessing the performance of the landing gear in the laboratory and testing its performance parameters such as the amount of work absorbed and landing load under various working conditions are of great reference significance for the overall design and performance evaluation of the helicopter. At present, when the laboratory tests the three-point wheeled landing gear system, it usually uses the reduced mass method to assess the single landing gear system. This situation is relatively simple and only requires balancing the overall delivery mass parameters. The integral landing gear is special because it is generally an integral structure. Therefore, when assessing its performance, it is usually necessary to refer to the takeoff weight status of the entire aircraft and conduct performance tests on it separately.

[0004] In this case, more physical parameter influencing factors need to be considered, including weight, center of gravity and moment of inertia. Whether these parameters are accurate and consistent with the actual situation will affect the accuracy of the entire test results. The traditional balancing adjustment device currently used in laboratory drop tests has a relatively fixed balancing point position, discontinuous center of gravity adjustment, and difficult adjustment of the counterweight block. It is only suitable for testing tasks of a single specification landing gear model. This is time-consuming, labor-intensive, and inefficient for tests that require multiple test states, and it is difficult to meet existing test needs.

[0005] Therefore, it is extremely important to design a new drop test trim adjustment device to overcome the shortcomings of traditional design methods and improve the efficiency and quality of landing gear drop tests. The currently disclosed test trim adjustment devices are mainly used for weight and center of gravity trim, and rarely involve moment of inertia parameter trim, which obviously cannot meet the performance test of landing gear. Based on the above considerations, the laboratory urgently needs to design a drop test trim adjustment device to meet the assessment of landing gear structural strength and performance tests. Summary of the invention

[0006] The purpose of the present invention is to provide a drop test balancing adjustment device and method, which can be used to realize the dynamic strength and performance assessment of the landing gear structure, mainly involving the tracking adjustment of the center of gravity position of the drop release hanging point, the decoupling of the counterweight mass, the adjustment of the counterweight position, the balancing of the center of gravity and the moment of inertia parameters and the installation of the test piece, etc., which can meet the precise assessment requirements for the dynamic strength and performance verification of the landing gear structure.

[0007] The present application provides a drop test balancing adjustment device, the device comprising: an extension arm 1, a longitudinal balancing rod 2, a main frame 3, a vertical balancing rod 4, a lateral balancing rod 5, a center of gravity tracking adjustment beam 6, a balancing block 7, a mounting interface 8, a lateral adjustment support 9, a guide limit plate 10, a floating hanging ear 11, an adjustment screw 12, and a rotating handle 13;

[0008] Among them, the side of the extension arm 1 is connected to the main frame 3 to assist in balancing the moment of inertia parameters in the pitch direction; the longitudinal balancing rod 2 is adjusted by sliding up and down along the slide groove on the extension arm 1 to track the center of gravity position, and the movable balancing block 7 is installed and adjusted laterally to achieve the adjustment of the moment of inertia and center of gravity; the lower end of the main frame 3 is designed with a mounting interface to achieve connection with the landing gear device, and the upper end is designed with a lifting interface to achieve 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 equipment;

[0009] The vertical trim rod 4 is adjusted by sliding forward and backward along the slide groove on the main frame 3 to track the center of gravity, and the movable trim block 7 is installed and adjusted vertically to achieve the adjustment of the moment of inertia and the center of gravity; the transverse trim rod 5 and the center of gravity tracking adjustment beam 6 cooperate to slide forward and backward along the slide groove on the main frame 3 to track the center of gravity, and the movable trim block 7 is installed and adjusted vertically and longitudinally to achieve the adjustment of the moment of inertia and the center of gravity;

[0010] The mounting interface 8 is arranged below the main frame 3 and is used to install and fix the landing gear device, and perform lateral and longitudinal adjustments in the plane; the lateral adjustment support 9 performs 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 posture; the adjustment screw 12 is used 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, and a narrow slot-shaped through hole is designed inside the extension arm 1 along the middle position of the vertical beam to install and adjust the upper and lower positions of the longitudinal balancing rod 2.

[0012] Preferably, the upper and lower positions of the main frame 3 are respectively designed with a lifting interface and a test piece installation interface, and the main frame 3 is also designed with a balancing rod, a center of gravity tracking adjustment beam 6 and various sensor installation interfaces.

[0013] Preferably, the longitudinal trim rod 2 , the vertical trim rod 4 and the transverse trim rod 5 are all of full thread design, and there are compression nuts on the trim rods for promoting the movement, adjustment and compression of the trim block 7 .

[0014] Preferably, the two end surfaces of the center of gravity tracking adjustment beam 6 are designed with mounting interfaces, which are fixedly connected to the main frame 3 , and a narrow and long slot-shaped through hole is designed in the middle for adjusting the transverse balancing rod 5 .

[0015] Preferably, a slot-shaped hole is designed at the bottom of the lateral adjustment support 9 to be fixedly connected to the main frame 3, and a bearing mounting groove is designed on the upper plate to install the bearing and the adjustment screw 12;

[0016] Mounting holes are designed at both ends of the guide limit plate 10 to be fixedly connected to the transverse adjustment support 9, and a narrow and long slot-shaped hole is designed in the middle.

[0017] Preferably, a threaded through hole and a limit foot are designed at the lower end of the movable hanging ear 11, and a semi-waist hole is designed at the upper part; the adjusting screw rod 12 is a full-thread structure connected and used in conjunction with the rotating handle 13.

[0018] In a second aspect, the present application also provides a drop test balancing adjustment method, the method comprising the following steps:

[0019] Step 1, install the longitudinal trim rod 2 on the extension arm 1 and connect it to the main frame 3, and connect the center of gravity tracking adjustment beam 6, the vertical trim rod 4, the transverse trim rod 5 and the test piece to the main frame 3 respectively;

[0020] Step 2, assemble the lateral adjustment support 9, the guide limit plate 10, the movable hanging ear 11, the adjustment screw rod 12, and the rotating handle 13 into a whole, and then connect them 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 quality parameter values;

[0022] Step 4: According to the trim target mass parameters required by the test, the trim position and mass distribution are calculated using an optimization algorithm, and then decoupled;

[0023] Step 5: Adjust all trim 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: According to the calculated decoupled balancing position and mass distribution, install the balancing block 7 on the balancing rod, adjust it to the corresponding position, and install and press it;

[0025] Step 7, adjusting the lateral position of the lateral adjustment support 9 and rotating the handle 13 to adjust the movable hanging ear 11, so that the plane coordinate position of the movable hanging ear 11 coincides with the center of gravity position;

[0026] Step 8. The above steps complete the test balancing work under the specified test state.

[0027] This application has the following technical effects:

[0028] The present invention belongs to the helicopter landing gear drop test technology, which can be used to realize the dynamic strength and performance assessment of the landing gear structure, mainly involving the tracking adjustment of the center of gravity position of the drop drop hanging point, the decoupling of the counterweight mass, the adjustment of the counterweight position, the balancing of the center of gravity and the moment of inertia parameters, and the installation of the test piece, etc., which can meet the precise assessment requirements for the dynamic strength and performance verification of the landing gear structure. The device can, to a certain extent, overcome the shortcomings of the traditional test balancing adjustment device, improve the test efficiency, improve the test quality, and can be flexibly applied to the verification work of the landing gear drop test of the same tonnage level configuration, greatly reducing the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Optimize the calculation flow chart for quality parameter balancing;

[0030] Figure 2 Isometric view of trim adjustment for drop test;

[0031] Figure 3 Isometric view of partial components of the trim adjustment device for drop test. DETAILED DESCRIPTION

[0032] The present invention focuses on a drop test balancing adjustment device and method, which can be used to achieve dynamic strength and performance assessment of landing gear structure, mainly involving tracking and adjusting the center of gravity position of the drop drop hanging point, decoupling of counterweight mass, adjustment of counterweight position, balancing of center of gravity and moment of inertia parameters and installation of test pieces, etc., which can meet the precise assessment requirements for dynamic strength and performance verification of landing gear structure. The device can improve test efficiency and test quality to a certain extent, and can be flexibly applied to the verification work of drop test of landing gear with the same tonnage level configuration, greatly reducing the test cost.

[0033] The drop test trim adjustment device includes: an extension arm 1, a longitudinal trim rod 2, a main frame 3, a vertical trim rod 4, a transverse trim rod 5, a center of gravity tracking adjustment beam 6, a trim block 7, a mounting interface 8, a transverse adjustment support 9, a guide limit plate 10, a floating hanging ear 11, an adjustment screw rod 12, and a rotating handle 13;

[0034] Its functional features are as follows: the side of the extension arm 1 is connected to the main frame 3, which mainly assists in balancing the moment of inertia parameters in the pitch direction; the longitudinal balancing rod 2 can be adjusted by sliding up and down along the slide groove on the extension arm 1 to track the center of gravity position, and the movable balancing block 7 can be installed and adjusted laterally to achieve the adjustment of the moment of inertia and center of gravity; the lower end of the main frame 3 is designed with a mounting interface to achieve connection with the landing gear device, and the upper end is designed with a lifting interface to achieve 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, balancing rods and various sensors and other equipment; the vertical balancing rod 4 can be adjusted by sliding back and forth along the slide groove on the main frame 3 to track the center of gravity position, and can The movable trim block 7 can be installed and adjusted vertically to achieve the adjustment of the moment of inertia and the center of gravity; the lateral trim rod 5 and the center of gravity tracking adjustment beam 6 can cooperate to adjust by sliding up and down and forward and backward along the slide groove on the main frame 3 to track the center of gravity position, and the movable trim block 7 can be installed and adjusted vertically and longitudinally to achieve the adjustment of the moment of inertia and the center of gravity; the installation interface 8 is arranged below the main frame 3 and is used to install a fixed landing gear device, which can be adjusted laterally and longitudinally in the plane; the lateral adjustment support 9 can be fine-tuned laterally to track the center of gravity position; the guide limit plate 10 keeps the floating hook 11 in a vertical posture; the adjustment screw 12 is used in conjunction with the rotating handle 13 to adjust the longitudinal position of the floating hook 11.

[0035] Its structural features are as follows: the extension arm 1 is fixedly connected to the front and rear ends of the main frame 3 respectively; a narrow slot-shaped through hole is designed inside the extension arm 1 along the middle position of the vertical beam, and the upper and lower positions of the longitudinal trim rod 2 can be installed and adjusted; the upper and lower positions of the main frame 3 are respectively designed with lifting interfaces and test piece installation interfaces, and the main frame 3 is also designed with a trim rod, a center of gravity tracking adjustment beam 6 and various sensor installation interfaces; the longitudinal trim rod 2, the vertical trim rod 4 and the transverse trim rod 5 are all fully threaded, and there are compression nuts on the trim rods to promote the movement, adjustment and compression of the trim block 7; the center of gravity tracking The two end surfaces of the tracking adjustment beam 6 are designed with installation interfaces, which can be fixedly connected with the main frame 3, and a narrow slot-shaped through hole is designed in the middle to adjust the transverse balancing rod 5; the bottom of the transverse adjustment support 9 is designed with a slot-shaped hole fixedly connected with the main frame 3, and the upper plate is designed with a bearing installation groove to install the bearing and the adjustment screw 12; the two ends of the guide limit plate 10 are designed with installation holes and fixedly connected with the transverse adjustment support 9, and a narrow slot-shaped hole is designed in the middle; the lower end of the floating hanging ear 11 is designed with a threaded through hole and a limit foot, and the upper part is designed with a half waist hole; the adjustment screw 12 is a full threaded structure connected to the rotating handle 13 for use. The above components together constitute a drop test balancing adjustment device.

[0036] Refer to the following Figure 1 , Figure 2 , Figure 3 This application is described in further detail.

[0037] The present application provides a drop test balancing adjustment method, comprising the following steps:

[0038] Step 1, install the longitudinal trim rod 2 on the extension arm 1 and connect it to the main frame 3, and connect the center of gravity tracking adjustment beam 6, the vertical trim rod 4, the transverse trim rod 5 and the test piece to the main frame 3 respectively;

[0039] Step 2, assemble the lateral adjustment support 9, the guide limit plate 10, the movable hanging ear 11, the adjustment screw rod 12, and the rotating handle 13 into a whole, and then connect them 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 quality parameter values;

[0041] in,

[0042] Initial mass: m0;

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

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

[0045] Step 4: According to the trim target mass parameters required by the test, the trim position and mass distribution are calculated using an optimization algorithm, and then decoupled;

[0046] in,

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

[0048] Target mass: m;

[0049] Target mass center position: x, y, z;

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

[0051] The optimization design constraint equation 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 quality 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] Balancing mass decoupling:

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

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

[0061] Trim 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] Among them, mx1, my1, mz1; mx2, my2, mz2 are the mass distributions after decoupling of the coordinate points (x1, y1, z1) and (x2, y2, z2).

[0070] Step 5: Adjust all trim 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: According to the calculated decoupled balancing position and mass distribution, install the balancing block 7 on the balancing rod, adjust it to the corresponding position, and install and press it;

[0072] Step 7, adjusting the lateral position of the lateral adjustment support 9 and rotating the handle 13 to adjust the movable hanging ear 11, so that the plane coordinate position of the movable hanging ear 11 coincides with the center of gravity position;

[0073] Step 8. The above steps complete the test balancing work under the established test state. After all measuring sensors are installed, the test work can begin.

[0074] The device of the present invention can achieve the consistency of the test state of the test piece falling and the state on the machine, and can achieve the firm clamping of the test piece and ensure the accurate transmission of dynamic force;

[0075] When using the device for testing, the tester first needs to have a detailed understanding of the initial parameters of the balancing adjustment device, and then use the device of the present invention to decouple the balancing position and mass distribution. The balancing adjustment device can simplify the balancing difficulty through the decoupling operation, making the balancing result more accurate, thereby achieving accurate consideration of the performance and dynamic strength of the landing gear device.

Claims

1. A drop test trim adjustment device, characterized in that: 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 center of gravity tracking adjustment beam (6), a balancing block (7), a mounting interface (8), a transverse adjustment support (9), a guide limit plate (10), a movable hanging ear (11), an adjustment screw rod (12), and a rotating handle (13); The side of the extension arm (1) is connected to the main frame (3) to assist in balancing the moment of inertia parameters in the pitch direction; the longitudinal balancing rod (2) tracks the center of gravity position by sliding up and down along the slide groove on the extension arm (1), and installs and laterally adjusts the moving balancing block (7) to achieve the adjustment of the moment of inertia and the center of gravity; the lower end of the main frame (3) is designed with a mounting interface to achieve connection with the landing gear device, and the upper end is designed with a lifting interface to achieve 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 sensor devices; The vertical trim rod (4) is adjusted by sliding forward and backward along the slide groove on the main frame (3) to track the center of gravity, and the movable trim block (7) is installed and adjusted vertically to achieve the adjustment of the moment of inertia and the center of gravity; the transverse trim rod (5) and the center of gravity tracking adjustment beam (6) cooperate to slide forward and backward along the slide groove on the main frame (3) to track the center of gravity, and the movable trim block (7) is installed and adjusted vertically and longitudinally to achieve the adjustment of the moment of inertia and the center of gravity; The mounting interface (8) is arranged below the main frame (3) and is used to mount a fixed landing gear device and perform lateral and longitudinal adjustments in a plane; the lateral adjustment support (9) performs fine adjustment in the lateral direction to track the center of gravity position; the guide limit plate (10) keeps the floating lug (11) in a vertical posture; the adjustment screw rod (12) is used in conjunction with the rotating handle (13) to adjust the longitudinal position of the floating lug (11).

2. The device according to claim 1, characterized in that The extension arm (1) is fixedly connected to the front and rear ends of the main frame (3) respectively. A narrow slot-shaped through hole is designed inside the extension arm (1) along the middle position of the vertical beam to install and adjust the upper and lower positions of the longitudinal balancing rod (2).

3. The device according to claim 2, characterized in that The main frame (3) is respectively designed with a lifting interface and a test piece installation interface at the upper and lower positions, and the main frame (3) is also designed with a balancing rod, a center of gravity tracking adjustment beam (6) and various sensor installation interfaces inside.

4. The device according to claim 3, characterized in that The longitudinal trim rod (2), the vertical trim rod (4) and the transverse trim rod (5) are all designed with full threads, and there are compression nuts on the trim rods for pushing the trim block (7) to move, adjust and tighten.

5. The device according to claim 4, characterized in that The center of gravity tracking adjustment beam (6) is designed with mounting interfaces at both end surfaces and is fixedly connected to the main frame (3). A narrow and long slot-shaped through hole is designed in the middle to adjust the transverse balancing rod (5).

6. The device according to claim 5, characterized in that The bottom of the lateral adjustment support (9) is designed with a slotted hole for fixed connection with the main frame (3), and the upper plate is designed with a bearing mounting groove for mounting the bearing and the adjustment screw (12); Mounting holes are designed at both ends of the guide limit plate (10) for fixed connection with the transverse adjustment support (9), and a narrow slot-shaped hole is designed in the middle.

7. The device according to claim 6, characterized in that The lower end of the movable hanging ear (11) is designed with a threaded through hole and a limit foot, and the upper part is designed with a half waist hole; the adjusting screw rod (12) is a full thread structure and is connected with the rotating handle (13) for use.

8. A drop test balancing adjustment method, characterized in that: The method comprises the following steps: Step 1, install the longitudinal trim rod (2) on the extension arm (1) and connect it to the main frame (3), and connect the center of gravity tracking adjustment beam (6), the vertical trim rod (4), the transverse trim rod (5) and the test piece to the main frame (3) respectively; Step 2, assemble the lateral adjustment support (9), the guide limit plate (10), the movable hanging ear (11), the adjustment screw rod (12), and the rotating handle (13) into a whole, and then connect them to the main frame (3); Step 3: Use relevant calculation tools to calculate the overall physical parameters of the above components and record the initial quality parameter values; Step 4: According to the trim target mass parameters required by the test, the trim position and mass distribution are calculated using an optimization algorithm, and then decoupled; Step 5: Adjust all trim 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; Step 6: According to the calculated decoupled 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; Step 7, adjusting the lateral position of the lateral adjustment support (9) and rotating the handle (13) to adjust the movable hanging ear (11) so that the plane coordinate position of the movable hanging ear (11) coincides with the center of gravity position; Step 8. The above steps complete the test balancing work under the specified test state.

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