Helicopter transfer function test suspension method and device

Abstract

The invention belongs to the technical field of helicopter whole-aircraft transfer function test suspension design, and discloses a helicopter transfer function test suspension method and device, and the method comprises the following steps: preparing a rigid annular hanging scaffold with a plurality of mooring holes, and the mooring holes are uniformly distributed in the hanging scaffold; flexible hangers penetrate through the mooring holes and are in rope sleeve connection with the hanging scaffold, and the hanging scaffold needs to be kept in a horizontal state after all the hangers are connected; each rope sleeve is connected with a rigid lifting hook; one end of a flexible bandage is tied to a propeller hub central part supporting arm, the other end of the flexible bandage is connected to a lifting hook, and the hanging scaffold needs to be kept in a horizontal state after all the bandages are connected. The problem that a suspension disc body structure is prone to fatigue or deformation in an existing suspension technology is solved, a vibration exciter excitation loading space is reserved in the center position of the propeller hub to implement center excitation loading work of the propeller hub, and meanwhile the effects of being simple, safe and stable are achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of helicopter transfer function test suspension design, specifically a method and device for helicopter transfer function test suspension that avoids the hub center excitation loading position and conflicts with the excitation loading device. This invention is particularly suitable for scenarios requiring high stability, uniform force distribution, and vertical excitation loading at the suspension center, such as aerospace testing, heavy machinery suspension devices, and dynamic load simulation of building structures. Background Art

[0002] From helicopter model development to design finalization, the entire aircraft undergoes three major dynamic characteristic tests to verify the rationality of the airframe's structural dynamic design. The test results are then used to optimize and improve the dynamic design. Transfer function testing is the most complex of these techniques. This requires flexible suspension of the entire aircraft. To avoid conflict with the excitation point, the suspension position must avoid the center of the hub. Furthermore, helicopter safety and test conditions must be ensured.

[0003] Currently, there is no technical research in my country on a test device specifically designed for transfer function testing, suspending the center of a helicopter hub, and applying excitation loading at the hub center, nor is there a specific test implementation method. This invention is specifically designed for full-helicopter transfer function testing. Its functions are as follows:

[0004] 1. Can simulate the free state of the helicopter;

[0005] 2. Different loading modes of the excitation source can be realized;

[0006] 3. Suitable for helicopter suspension methods where the hub center needs to be avoided.

[0007] So far, there is no similar suspension method in my country that needs to avoid the center position of the hub, and no relevant public literature has been seen abroad.

[0008] Traditional suspension systems typically apply loads directly to the suspension disc, subjecting it to vertical tension and potentially causing structural fatigue or deformation. Furthermore, uneven load distribution across multiple suspensions can cause system wobbling and compromise stability. Existing technologies lack space for vertical excitation loading, limiting their application in precision testing scenarios.

[0009] The solution of the present invention provides a suspension method and device, which avoids the center position of the hub and reserves space for excitation loading of the exciter to implement the hub center excitation loading work, and has the effects of simplicity, safety and stability. Summary of the Invention

[0010] This invention addresses the problem that traditional suspension systems typically apply loads directly to the suspension disc, resulting in vertical tension on the disc and easily causing structural fatigue or deformation. This invention proposes a suspension method and device that avoids the central excitation loading position at the hub while still suspending the helicopter hub. By optimizing the force transmission path, the disc only bears radial pressure, avoiding the relatively greater vertical tension of the suspension. This ensures uniform force distribution across multiple suspensions and improves system stability.

[0011] The technical solution of the present invention is achieved as follows:

[0012] In a first aspect, the present invention discloses a helicopter transfer function test suspension method, which comprises the following steps:

[0013] Prepare a rigid ring-shaped hanging plate with several mooring holes, with at least 3 mooring holes evenly distributed on the hanging plate;

[0014] Use a flexible hanging hook to pass through the mooring hole and form a rope loop connection with the hanging plate. After all the hanging connections are completed, the hanging plate must be kept in a horizontal state;

[0015] A rigid hook is connected to each of the above-mentioned rope loops;

[0016] Use a flexible strap to tie one end to the propeller hub centerpiece support arm and the other end to the hook. After all straps are connected, keep the hoisting platform in a horizontal state.

[0017] As a further solution of the present invention: the hanging plate is made of high-strength metal and is provided with five evenly distributed mooring holes, and the edges of the mooring holes are smoothed with curved surfaces;

[0018] The sling is made of one or more of a flexible steel cable, a carbon fiber rope, and a nylon woven rope. One end of the sling is made into a rope loop. After the sling passes through the mooring hole, it passes through the rope loop to form a rope loop connection with the hanging plate.

[0019] The hook adopts an integrated or split design; when the integrated design is adopted, one end is provided with a hanging hole and the other end is provided with a hook, and the hook is mounted on the hanging through the hanging hole; when the split design is adopted, it includes a damping buffer and two hooks symmetrically arranged and respectively connected to the two ends of the damping buffer, one of which is hung on the rope loop of the hanging;

[0020] The strap is a high-toughness nylon rope or a woven cloth rope; it is folded in half, with one end hung on the hook and the other end tied to the propeller hub central piece support arm; or one end is connected to the hook to form a rope loop, and the other end is tied to the propeller hub central piece support arm.

[0021] As a further solution of the present invention, the strap and the sling are connected by a hook, and a safety rope is provided between the strap and the sling for connecting the strap and the sling when the hook breaks.

[0022] In a second aspect, the present invention discloses a helicopter transfer function test suspension device, comprising:

[0023] The hanging plate adopts a ring-shaped design and has five mooring holes evenly arranged on the hanging plate;

[0024] The hanging part is a flexible part with the same number as the mooring holes, one end of which passes through the mooring hole to form a rope loop connection with the hanging plate;

[0025] The hook is a rigid part connected to the hanging rope loop;

[0026] The strap is a flexible piece, one end of which is tied to the support arm of the central piece of the hub, and the other end is connected to the hook.

[0027] As a further solution of the present invention: 5 mooring holes are evenly opened on the hanging plate, and the edges of the mooring holes need to be processed to smooth the curved surface.

[0028] As a further solution of the present invention: the sling is made of one or more of a flexible steel cable, a carbon fiber rope, and a nylon cloth woven rope, and one end of the sling is made into a rope loop. After the sling passes through the mooring hole, it passes through the above-mentioned rope loop knot to form a rope loop connection with the hanging plate.

[0029] As a further solution of the present invention: a hanging hole is provided at one end of the hook, and a hook is provided at the other end, and the hook is sleeved on the hook through the hanging hole.

[0030] As a further solution of the present invention: the hook adopts a split design, including a damping buffer and two symmetrically arranged hooks respectively connected to the two ends of the damping buffer, one of the hooks is hung on the hanging rope loop.

[0031] As a further solution of the present invention: the strap is a high-toughness nylon rope or a woven cloth rope, which is folded in half, with one end hung on the hook and the other end tied to the support arm of the central part of the hub; or one end is connected to the hook to form a rope loop, and the other end is tied to the support arm of the central part of the hub.

[0032] As a further solution of the present invention, a safety rope is provided between the strap and the sling, which is used to connect the strap and the sling when the hook breaks.

[0033] The beneficial effects of this application are:

[0034] 1. This application can achieve: simulating the suspension state of a helicopter; implementing excitation loading at the center of the hub; and can be used to implement vertical excitation loading at the center of the hub for helicopters of different models and tonnages.

[0035] 2. This application allows for both vertical excitation loading at the center of the helicopter hub and simultaneous suspension at the hub center. This solution enables suspension testing of the entire helicopter transfer function, measuring the transfer function from the hub center to various areas of interest, and providing a test basis for vibration analysis, vibration control, and structural layout.

[0036] 3. The service life of the structure of this application is extended: the force pattern of the disk is optimized to avoid alternating vertical stress and improve fatigue life.

[0037] 4. The dynamic stability of this application is enhanced: the self-adaptive adjustment capability of the suspension enables the system to remain stable under impact loads and reduce the amplitude.

[0038] 5. This application has high functional integration: reserved excitation loading space and other standardized interfaces support rapid integration and replacement of excitation loading devices.

[0039] 6. This application is easy to maintain: the quick-release strap and modular hook design make it easy to replace parts and debug on site.

[0040] 7. This application adopts a decoupling design: the hook has no direct contact with the hanging plate, but directly contacts the hanging, completely isolating the influence of vertical tension on the hanging plate.

[0041] 8. This application can be modularly expanded: the outer diameter of the hanging plate can be designed to a standardized size, supporting multiple plates in series or parallel, suitable for different load scale requirements.

[0042] 9. This application adopts a redundant protection design: the mooring hole is chamfered or embedded with a wear-resistant bushing to prevent friction loss during hanging; a double-layer protection device of a hook and a safety rope is set between the hanging and the strap. When the hook breaks, the safety rope can act as a connection to prevent the hanging and the strap from detaching.

[0043] The present application is described in further detail below with reference to the accompanying drawings of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention is a schematic diagram of a helicopter transfer function test suspension device.

[0045] Explanation of the reference numerals in the figures: 1. hanging; 2. hanging plate; 3. hook; 4. strap. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Throughout the drawings, identical or similar reference numerals represent identical or similar elements or elements having identical or similar functions. The described embodiments are only some, not all, of the embodiments of the present invention.

[0047] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0048] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0049] The following is combined with Figure 1 The embodiments of the present invention are described in detail.

[0050] Example 1

[0051] The present invention discloses a helicopter transfer function test suspension method, which comprises the following steps:

[0052] Prepare a rigid annular hanging plate 2 with a plurality of mooring holes, wherein the mooring holes are at least 3 and evenly distributed on the hanging plate 2;

[0053] Use the flexible hanging hook 1 to pass through the mooring hole and form a rope loop with the hanging plate 2. After all the hanging hooks 1 are connected, keep the hanging plate 2 in a horizontal state;

[0054] A rigid hook 3 is connected to each of the above rope loops;

[0055] Use a flexible strap 4 to tie one end to the hub centerpiece support arm, and the other end to connect to the hook 3. After all the straps 4 are connected, the hanging plate 2 must be kept in a horizontal state.

[0056] This suspension method enables the suspension 1 to be connected to the suspension plate 2, the suspension 1 to be connected to the hook 3, the suspension plate 2 to be not directly connected to the hook 3, and the strap 4 to be connected to the hook 3. Through the above design, the present invention is significantly superior to existing suspension methods in terms of structural stability, functional scalability and durability, and has broad industrial application prospects.

[0057] The hanging plate 2 is machined into a ring shape from high-strength metal (such as aviation aluminum or 45-gauge steel) with an inner diameter of 600mm, an outer diameter of 900mm, and a thickness of 40mm. It is capable of carrying in-plane compressive loads. Five mooring holes are evenly distributed throughout the hanging plate 2, and their edges are curved and smoothed. The mooring holes are 100mm in diameter and chamfered to reduce stress concentration and the risk of sharp edges cutting the hangers 1. These evenly spaced mooring holes are used to connect and tie the five hangers 1. Wear-resistant bushings can also be inserted into the mooring holes to prevent friction wear on the hangers 1.

[0058] The sling 1 is made of one or more of a flexible steel cable, carbon fiber rope, or nylon cloth rope. One end of the sling 1 is formed into a loop knot. After passing through the mooring holes, the sling 1 is then threaded through the loop knot, forming a loop connection with the suspension plate 2. Five flexible steel cables, carbon fiber ropes, or nylon cloth ropes of equal strength and length, each with loops (loop knots) at the front, serve as the sling 1. These are threaded through evenly spaced mooring holes on the suspension plate 2 and then tied to the suspension plate 2 through the rope's own loops. The other end of the sling 1 can be connected to a load-bearing component via a universal joint.

[0059] The hook 3 adopts an integrated or split design; when an integrated design is adopted, a hanging hole is provided at one end and a hook is provided at the other end, and the hook 3 is mounted on the suspension 1 through the hanging hole; when a split design is adopted, it includes a damping buffer and two symmetrically arranged hooks respectively connected to the two ends of the damping buffer, one of which is hung on the rope loop of the suspension 1, and the other is connected to the strap 4. A damping buffer is used for transition in the middle to avoid transmitting impact loads. The hook 3 is connected to the rope loop of the suspension 1 below the suspension plate 2, and is not directly connected to the mooring hole of the suspension plate 2, and does not contact the suspension plate 2 to generate force interaction.

[0060] The strap 4 is a high-toughness nylon rope or a woven rope; it has several connection methods:

[0061] Among them, the first method is to fold it in half, hang one end on the hook, and tie the other end to the support arm of the central part of the hub.

[0062] The second type is that one end is connected to the hook to form a rope loop, and the other end is tied to the support arm of the central part of the hub.

[0063] The third type is to tie one end to the propeller hub centerpiece support arm, and the other end is connected to the hook through a quick-release buckle, which supports quick replacement and tension fine-tuning.

[0064] The strap 4 and the sling 1 are connected via a hook 3 , and a safety rope is provided between the strap 4 and the sling 1 for connecting the strap 4 and the sling 1 when the hook 3 breaks.

[0065] In the present invention, the five straps 4 for suspending the five arms of the hub central piece are tied to the hooks 3 on the sling 1 instead of being directly tied to the mooring holes of the hanging plate 2.

[0066] Working principle of the present invention:

[0067] 1) Force transmission path: The suspended load is transmitted through the strap 4 → hook 3 → suspension 1, and finally to the suspension 1. The suspension plate 2 is only subjected to the inward radial pressure generated by the tension of the suspension 1, and there is no vertical suspended load component.

[0068] 2) Load-balancing mechanism: The flexible nature of the suspension 1, combined with the universal joint design, allows each suspension 1 to automatically adjust its tension under dynamic loads, ensuring that all five suspensions 1 are evenly loaded and do not cause unstable suspension.

[0069] 3) Vertical excitation loading: A space is reserved in the center area of the suspension plate 2 (inner diameter 600mm) for installing a hydraulic or electromagnetic exciter to apply vertical vibration or periodic loads for structural dynamic tests such as full-machine transfer function tests.

[0070] Example 2

[0071] The present invention discloses a helicopter transfer function test suspension device, which comprises:

[0072] The hanging plate 2 is annular in design and has five mooring holes evenly arranged on the hanging plate 2;

[0073] Hanging 1, which is a flexible member, has the same number as the mooring holes, one end of which passes through the mooring hole to form a rope loop connection with the hanging plate 2;

[0074] The hook 3 is a rigid part connected to the rope loop of the hanger 1;

[0075] The strap 4 is a flexible member, one end of which is tied to the arm of the hub central member, and the other end is connected to the hook 3.

[0076] The suspension load is transferred through the strap 4 → hook 3 → suspension 1, and finally to the suspension 1. The suspension plate 2 is only subjected to the inward radial pressure generated by the tension of the suspension 1, and has no vertical suspension load component.

[0077] The hanging plate 2 is machined into a ring shape from high-strength metal (such as aviation aluminum or 45-gauge steel) with an inner diameter of 600mm, an outer diameter of 900mm, and a thickness of 40mm. It is capable of carrying in-plane compressive loads. Five mooring holes are evenly distributed throughout the hanging plate 2, and their edges are curved and smoothed. The mooring holes are 100mm in diameter and chamfered to reduce stress concentration and the risk of sharp edges cutting the hangers 1. These evenly spaced mooring holes are used to connect and tie the five hangers 1. Wear-resistant bushings can also be inserted into the mooring holes to prevent friction wear on the hangers 1.

[0078] The sling 1 is made of one or more of a flexible steel cable, carbon fiber rope, or nylon cloth rope. One end of the sling 1 is formed into a loop knot. After passing through the mooring holes, the sling 1 is then threaded through the loop knot, forming a loop connection with the suspension plate 2. Five flexible steel cables, carbon fiber ropes, or nylon cloth ropes of equal strength and length, each with loops (loop knots) at the front, serve as the sling 1. These are threaded through evenly spaced mooring holes on the suspension plate 2 and then tied to the suspension plate 2 through the rope's own loops. The other end of the sling 1 can be connected to a load-bearing component via a universal joint.

[0079] The hook 3 adopts an integrated or split design;

[0080] When an integrated design is adopted, one end of the hook 3 is provided with a hanging hole, and the other end is provided with a hook, and the hook 3 is sleeved on the hanger 1 through the hanging hole.

[0081] When a split design is used, it includes a damping buffer and two symmetrically arranged hooks connected to each end of the damping buffer. One hook is attached to the rope loop of the suspension 1, and the other is connected to the binding strap 4. The damping buffer is used as a transition in the middle to avoid the transmission of impact loads. The hook 3 is connected to the rope loop of the suspension 1 below the suspension plate 2, and is not directly connected to the tie-down hole of the suspension plate 2, so there is no contact with the suspension plate 2 to generate force interaction.

[0082] The strap 4 is a high-toughness nylon rope or a woven rope, and has several connection methods:

[0083] Among them, the first method is to fold it in half, hang one end on the hook, and tie the other end to the support arm of the central part of the hub.

[0084] The second type is that one end is connected to the hook to form a rope loop, and the other end is tied to the support arm of the central part of the hub.

[0085] The third type is to tie one end to the propeller hub centerpiece support arm, and the other end is connected to the hook through a quick-release buckle, which supports quick replacement and tension fine-tuning.

[0086] The strap 4 and the sling 1 are connected via a hook 3 , and a safety rope is provided between the strap 4 and the sling 1 for connecting the strap 4 and the sling 1 when the hook 3 breaks.

[0087] The present invention optimizes the force transmission path so that the hanging plate 2 only bears radial pressure and avoids bearing the relatively larger vertical pulling force of the suspension, thereby ensuring that the multiple hangers 1 are evenly stressed and improving the stability of the system.

[0088] The present invention allows for both vertical excitation loading at the center of the helicopter hub and simultaneous suspension at the hub center. This allows for suspension testing of the entire helicopter's transfer function, measuring the transfer function from the hub center to various locations of interest, and providing a test basis for vibration analysis, vibration control, and structural layout.

[0089] So far, the purpose of the present invention has been accomplished.

[0090] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A helicopter transfer function test suspension method, characterized in that: The following steps are involved: Prepare a rigid ring-shaped hanging plate with several mooring holes, with at least 3 mooring holes evenly distributed on the hanging plate; Use a flexible hanging hook to pass through the mooring hole and form a rope loop connection with the hanging plate. After all the hanging connections are completed, the hanging plate must be kept in a horizontal state; A rigid hook is connected to each of the above-mentioned rope loops; Use a flexible strap to tie one end to the propeller hub centerpiece support arm and the other end to the hook. After all straps are connected, keep the hoisting platform in a horizontal state.

2. A helicopter transfer function test suspension method according to claim 1, characterized in that: The hanging plate is made of high-strength metal and is provided with five evenly distributed mooring holes, and the edges of the mooring holes are smoothed with curved surfaces; The sling is made of one or more of a flexible steel cable, a carbon fiber rope, and a nylon woven rope. One end of the sling is made into a rope loop. After the sling passes through the mooring hole, it passes through the rope loop to form a rope loop connection with the hanging plate. The hook adopts an integrated or split design; when the integrated design is adopted, one end is provided with a hanging hole and the other end is provided with a hook, and the hook is mounted on the hanging through the hanging hole; when the split design is adopted, it includes a damping buffer and two hooks symmetrically arranged and respectively connected to the two ends of the damping buffer, one of which is hung on the rope loop of the hanging; The strap is a high-toughness nylon rope or a woven cloth rope; it is folded in half, with one end hung on the hook and the other end tied to the propeller hub central piece support arm; or one end is connected to the hook to form a rope loop, and the other end is tied to the propeller hub central piece support arm.

3. A helicopter transfer function test suspension method according to claim 2, characterized in that: The strap and the sling are connected via a hook, and a safety rope is provided between the strap and the sling for connecting the strap and the sling when the hook breaks.

4. A helicopter transfer function test suspension device, characterized in that: include: The hanging plate adopts a ring-shaped design and has five mooring holes evenly arranged on the hanging plate; The hanging part is a flexible part with the same number as the mooring holes, one end of which passes through the mooring hole to form a rope loop connection with the hanging plate; The hook is a rigid part connected to the hanging rope loop; The strap is a flexible piece, one end of which is tied to the support arm of the central piece of the hub, and the other end is connected to the hook.

5. A helicopter transfer function test suspension device according to claim 4, characterized in that: Five mooring holes are evenly opened on the hanging plate, and the edges of the mooring holes need to be smoothed.

6. A helicopter transfer function test suspension device according to claim 5, characterized in that: The sling is made of one or more of a flexible steel cable, a carbon fiber rope, and a nylon cloth woven rope. One end of the sling is made into a rope loop. After the sling passes through the mooring hole, it passes through the rope loop knot to form a rope loop connection with the hanging plate.

7. A helicopter transfer function test suspension device according to claim 6, characterized in that: One end of the hook is provided with a hanging hole, and the other end is provided with a hook, and the hook is sleeved on the hook through the hanging hole.

8. The helicopter transfer function test suspension device according to claim 6, characterized in that: The hook adopts a split design, including a damping buffer and two hooks symmetrically arranged and respectively connected to the two ends of the damping buffer, one of the hooks is hung on the hanging rope loop.

9. A helicopter transfer function test suspension device according to claim 7 or 8, characterized in that: The strap is a high-toughness nylon rope or a woven cloth rope, which is folded in half, with one end hung on the hook and the other end tied to the propeller hub central piece support arm; or one end is connected to the hook to form a rope loop, and the other end is tied to the propeller hub central piece support arm.

10. A helicopter transfer function test suspension device according to claim 9, characterized in that: A safety rope is also provided between the strap and the sling, which is used to connect the strap and the sling when the hook breaks.

Images