A kind of shaking, vibration and acceleration test fixture of helicopter anti-crash soft oil tank

Abstract

The utility model relates to a kind of sway, vibration and acceleration test fixture of helicopter anti-crash soft oil tank, including support frame, interface mounting column, base and energy-absorbing block fixing structure, the support frame is connected by bolt with base, the support frame shape is closed polyhedral frame structure, the side wall and upper surface of the support frame are respectively fixed with four categories of installation column of oil filler, oil outlet, air vent and intercommunication pipe accessory, the base central fixedly connected with the energy-absorbing block fixing mechanism matched with experimental soft oil tank energy-absorbing block.The utility model is integrated, and the test efficiency is improved by more than 50% by clamp supporting vibration, sway, acceleration three kinds of test;Nylon hasp flexible constraint oil tank, realize nondestructive fixation, no indentation, scratch on the surface of oil tank after test;By interface mounting column simulation real constraint, energy-absorbing tool ensures that anti-crash function effectively triggers, accurate assessment, test authenticity is significantly improved;It is easy to operate, can replace base, quickly adapt to different test table.

Description

Technical Field

[0001] This utility model belongs to the field of aircraft ground testing technology, and in particular relates to a test fixture for shaking, vibration and acceleration of helicopter crash-resistant soft fuel tanks. Background Technology

[0002] Crash-resistant flexible fuel tanks are critical components for ensuring the survival of helicopter occupants in accidental crashes. Their design must meet functional requirements under complex mechanical environments such as extreme vibration, severe sloshing (e.g., fuel sloshing loads), and high-g impact accelerations. This includes maintaining a tight seal, preventing rupture, controlling fuel sloshing, and ensuring effective energy absorption through the collapse of energy-absorbing components. Therefore, during the research and development and production phases, rigorous ground simulation tests are essential for comprehensively evaluating the mechanical properties of the fuel tanks.

[0003] Currently, the main technical challenges and shortcomings of existing fixtures in conducting such mechanical tests on fuel tanks are as follows: 1) Limited Functionality and Low Testing Efficiency of Fixtures: Traditional test fixtures are primarily designed for a single test type (such as vibration testing or shaking testing only). When multiple tests, such as vibration, shaking, and crash acceleration, need to be performed on the same fuel tank, different fixtures must be frequently changed. This is not only cumbersome, time-consuming, and inefficient, but repeated disassembly and assembly can also lead to changes in the fuel tank's positioning reference, introducing additional errors and affecting the accuracy and comparability of test data.

[0004] 2) Difficulty in securing flexible fuel tanks: Crash-resistant fuel tanks are typically made of flexible composite materials, and their shape may change under no-load and full-load conditions. Existing fixtures mostly use rigid clamping or binding methods for fixation, which can easily cause local damage to the fuel tank wall during testing (such as indentations or scratches), or cannot effectively limit the undesired deformation of the fuel tank, resulting in distorted test results that cannot truly reflect the performance of the fuel tank in the installed state.

[0005] 3) Inadequate interface simulation and fixation: The fuel tank's filler neck, fuel inlet, vent, and connecting pipe accessories are key functional points and potential weak points. Existing fixtures often fail to accurately or securely simulate and fix these interfaces, making it difficult to realistically simulate their installation constraints and stress conditions on the machine body, thus affecting the accuracy of the interface area's performance under mechanical loads.

[0006] 4) Missing or unreliable securing of energy-absorbing components: The core of a crash-resistant fuel tank lies in its integrated energy-absorbing structure. Existing fixtures generally lack designs specifically for reliably securing these energy-absorbing components during testing. If the energy-absorbing components shift or detach during testing, their energy-absorbing function cannot be effectively assessed, rendering the critical "crash resistance" verification ineffective.

[0007] 5) Poor platform adaptability: Different laboratories may use different models and specifications of vibration tables, shaking tables, or accelerometers. The base interfaces of existing fixtures are usually fixed and lack versatility. To adapt to different test platforms, it is often necessary to customize adapter plates or modify the fixture base, which increases cost and complexity.

[0008] Therefore, there is an urgent need to develop a specialized test fixture that is highly integrated, versatile, and easy to install and reliable. This fixture can complete multiple key mechanical environment tests, such as vibration, swaying, and crash acceleration, of helicopter crash-resistant soft fuel tanks on a single device. It can also accurately simulate fuel tank interface constraints, reliably fix energy-absorbing components, and be compatible with various test platforms to significantly improve test efficiency, data accuracy, and test coverage. Utility Model Content

[0009] This invention aims to overcome the shortcomings of existing technologies and address the problems of limited functionality, damage to flexible fuel tanks, distorted interface constraints, missing energy-absorbing components, and poor platform adaptability of existing test fixtures. It provides a test fixture for the shaking, vibration, and acceleration of helicopter crash-resistant flexible fuel tanks, achieving non-destructive fixing of the flexible fuel tank, reliable fixing of energy-absorbing components, and ensuring effective verification of crash-resistant functionality; it is also compatible with various test platforms.

[0010] To achieve the above objectives, this utility model provides a test fixture for the shaking, vibration, and acceleration of a helicopter crash-resistant soft fuel tank. The fixture includes a support frame, interface mounting columns, a base, and an energy-absorbing block fixing structure. The support frame is connected to the base by bolts. The support frame has a closed polyhedral frame structure. Four types of mounting columns—a refueling port, a fuel inlet, a vent, and a connecting pipe accessory—are fixed to the side walls and upper surface of the support frame, respectively. An energy-absorbing block fixing mechanism matching the energy-absorbing block of the experimental soft fuel tank is fixed to the center of the base.

[0011] Preferably, the support frame has an isosceles trapezoidal cross-sectional shape and is made of metal plate.

[0012] Preferably, an oil inlet mounting post and a vent mounting post are fixedly connected to the upper surface of the support frame, a connecting pipe accessory mounting post is fixedly connected to the left side wall of the support frame, and an oil filler mounting post is fixedly connected to the right side wall of the support frame.

[0013] Preferably, the inner wall of the support frame is fixed with a plurality of Velcro arrays.

[0014] Preferably, the Velcro fastener is a Velcro closure.

[0015] Preferably, the mounting column has several bolt holes evenly distributed along its circumference, and is fixed to the interface of the experimental soft oil tank by through bolts.

[0016] Preferably, the base includes a fixed bracket and a base plate. The fixed bracket is fixedly connected to the four edges of the base plate. The fixed bracket has a plurality of bolt holes along its longitudinal direction. The cross-sectional shape of the base matches the cross-sectional shape of the support frame and is fixedly connected to the support frame by bolts.

[0017] Preferably, the base plate is provided with a standardized bolt through-hole array for connection with different test benches.

[0018] Preferably, the shape of the energy-absorbing block fixing mechanism matches the shape of the energy-absorbing block of the experimental soft oil tank.

[0019] Beneficial effects: Compared with the prior art, this utility model has strong integration, and the fixture supports three types of tests: vibration, shaking and acceleration, improving test efficiency by more than 50%; the nylon hook-and-loop flexible constraint oil tank achieves non-destructive fixation, and the surface of the oil tank is free of indentations and scratches after the test; the interface mounting column simulates real constraint, and the energy-absorbing tooling ensures that the anti-fall function is effectively triggered, accurately assesses and significantly improves the authenticity of the test; it is easy to operate, and the base can be replaced to quickly adapt to different test benches. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall design of this utility model; Figure 2 yes Figure 1 Diagram showing the location of the Velcro fastener; Figure 3 This is a schematic diagram showing the position of the energy-absorbing block fixing mechanism and the base; Figure 4 This is a schematic diagram of the replaceable base bolt through-hole array; Figure 5 This is a schematic diagram of the installation of this utility model and the vibration table; Figure 6 It is the test curve diagram of the vibration test; Figure 7 It is the test curve graph of the shaking test; Figure 8 It is an experimental curve of acceleration.

[0021] In the diagram: 1. Support frame, 2. Base, 2-1. Fixed bracket, 2-2. Base plate, 3. Energy-absorbing block fixing mechanism, 4. Oil inlet mounting column, 5. Vent inlet mounting column, 6. Connecting pipe accessory mounting column, 7. Oil filling port mounting column, 8. Velcro, 9. Bolt through hole, 10. Vibration table.

[0022] A-Test Fixture Detailed Implementation

[0023] The following detailed description of the specific implementation of the present invention, in conjunction with preferred embodiments, is as follows: Referring to the accompanying drawings, this embodiment provides a test fixture for the shaking, vibration, and acceleration of a helicopter crash-resistant soft fuel tank, including a support frame 1, interface mounting columns, a base 2, and an energy-absorbing block fixing mechanism 3. The support frame is connected to the base by bolts. The support frame has a closed polyhedral frame structure. Four types of mounting columns—fuel inlet, fuel outlet, vent, and connecting pipe accessories—are fixedly connected to the side walls and upper surface of the support frame, respectively. An energy-absorbing block fixing mechanism matching the energy-absorbing block of the experimental soft fuel tank 11 is fixedly connected to the center of the base.

[0024] In a preferred embodiment, the support frame has an isosceles trapezoidal cross-sectional shape and is made of metal plate.

[0025] In a preferred embodiment, an oil inlet mounting post 4 and a vent mounting post 5 are fixedly connected to the upper surface of the support frame; a connecting pipe accessory mounting post 6 is fixedly connected to the left side wall of the support frame; and a filler port mounting post 7 is fixedly connected to the right side wall of the support frame. The experimental soft fuel tank interface is precisely fixed with bolts to simulate real installation rigidity.

[0026] In a preferred embodiment, the inner wall of the support frame is covered with an array of Velcro straps. These are used to flexibly restrain the tank wall and prevent localized stress damage. In this embodiment, the Velcro straps are Velcro.

[0027] See appendix for details Figure 4 In a preferred embodiment, the mounting column has several bolt holes 9 evenly distributed around its circumference, which are fixed to the interface of the experimental soft oil tank by through bolts.

[0028] In a preferred embodiment, the base includes a fixed bracket 2-1 and a base plate 2-2. The fixed bracket is fixedly connected to the four edges of the base plate. The fixed bracket has several bolt holes along its longitudinal direction. The cross-sectional shape of the base matches the cross-sectional shape of the support frame and is fixedly connected to the support frame by bolts. The base is a detachable and replaceable structure with a standardized array of connection holes, allowing for replacement and connection to different test benches.

[0029] In a preferred embodiment, the base plate is provided with a standardized bolt through-hole array for connection with different test benches.

[0030] In a preferred embodiment, the shape of the energy-absorbing block fixing mechanism matches the shape of the energy-absorbing block in the experimental soft oil tank. It is installed at the bottom of the fixing bracket to ensure that the energy-absorbing component does not shift during shaking, vibration, and acceleration tests. Example

[0031] Taking the vibration test of a certain type of helicopter fuel tank as an example Taking an experimental soft oil tank as an example, it includes an oil inlet, a vent, a connecting pipe accessory, an oil filling inlet, and an energy-absorbing block.

[0032] 1. Place the unloaded flexible oil tank into the support frame, press the wall of the experimental flexible oil tank to make it adhere to the inner nylon fastener, and ensure uniform force in the circumference. 2. Align the filler port, oil inlet, vent, and connecting pipe of the experimental soft oil tank with the corresponding mounting posts, and tighten them with M6 bolts through the interface flange and the threaded holes of the mounting posts. 3. Insert the energy-absorbing block at the bottom of the experimental soft oil tank into the energy-absorbing block fixing mechanism; 4. Select a base according to the interface size of the vibration table, and use M16 screws to fasten the base of experimental fixture A to the vibration table. 5. Align the bottom of the support frame with the fixing bracket connection hole of the base, and tighten it with M12 bolts through the connection hole; 6. According to the test requirements, inject 80% of the volume of simulated fuel into the experimental soft fuel tank and apply the corresponding vibration test; 7. After the vibration test, check the oil tank for oil leaks, surface damage, and whether the Velcro fasteners have come loose. Also check whether the energy-absorbing components have collapsed according to the design and whether the tooling is loose.

[0033] The above detailed description of a test fixture for shaking, vibration and acceleration of a helicopter crash-resistant soft fuel tank, with reference to the embodiments described above, is illustrative rather than limiting. Several embodiments can be listed according to the defined scope. Therefore, changes and modifications without departing from the overall concept of this utility model should be within the protection scope of this utility model.

Claims

1. A test fixture for shaking, vibration, and acceleration of a helicopter crash-resistant flexible fuel tank, characterized in that: It includes a support frame, interface mounting columns, a base, and an energy-absorbing block fixing structure. The support frame is connected to the base by bolts. The support frame is a closed polyhedral frame structure. The side walls and upper surface of the support frame are respectively fixed with four types of mounting columns: oil filling port, oil delivery port, vent port, and connecting pipe accessories. The center of the base is fixed with an energy-absorbing block fixing mechanism that matches the energy-absorbing block of the experimental soft oil tank.

2. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant flexible fuel tanks according to claim 1, characterized in that: The support frame has an isosceles trapezoidal cross-section and is made of metal plate.

3. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant flexible fuel tanks according to claim 1 or 2, characterized in that: An oil inlet mounting post and a vent mounting post are fixedly connected to the upper surface of the support frame. A connecting pipe accessory mounting post is fixedly connected to the left side wall of the support frame, and an oil filler mounting post is fixedly connected to the right side wall of the support frame.

4. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant soft fuel tanks according to claim 3, characterized in that: The inner wall of the support frame is fixed with several arrays of Velcro fasteners.

5. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant soft fuel tanks according to claim 4, characterized in that: The Velcro fasteners are made of Velcro.

6. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant flexible fuel tanks according to claim 1, characterized in that: The four types of mounting columns have several bolt holes evenly distributed around their circumference, which are fixed to the interface of the experimental soft oil tank by through bolts.

7. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant flexible fuel tanks according to claim 1, characterized in that: The base includes a fixed bracket and a base plate. The fixed bracket is fixedly connected to the four edges of the base plate. The fixed bracket has multiple bolt holes along its longitudinal direction. The cross-sectional shape of the base matches the cross-sectional shape of the support frame and is fixedly connected to the support frame by bolts, forming a detachable and replaceable structure.

8. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant flexible fuel tanks according to claim 7, characterized in that: The base plate is equipped with a standardized bolt through-hole array for connection with different test benches.

9. The test fixture for shaking, vibration, and acceleration of helicopter crash-resistant soft fuel tanks according to claim 1, characterized in that: The shape of the energy-absorbing block fixing mechanism matches the shape of the energy-absorbing block in the experimental soft oil tank.

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