Fatigue test device for electric winch joint of search and rescue helicopter

Abstract

The invention belongs to the technical field of winch joint fatigue test, and discloses a fatigue test device for an electric winch joint of a search and rescue helicopter, which comprises a bottom fixing plate fixedly connected to a bearing ground rail of a plant; the test piece boundary simulation frame is fixedly connected to the bottom fixing plate, the winch joint test piece is arranged in the test piece boundary simulation frame, and the real use state of the search and rescue helicopter winch joint is simulated; one end of the dowel bar false piece is inserted into the winch joint test piece and is fixedly connected with the winch joint test piece through an anti-loosening bolt; the two loading assemblies are connected to the dowel bar false piece in parallel, and a certain distance is formed between the two connecting point positions; and the three bearing handle assemblies are respectively connected to the other ends of the two loading assemblies and the dowel bar false piece. According to the invention, the problem that the fatigue test cannot be carried out on the winch joint in the prior art is solved, and effective data support is provided for structural design and improvement and life evaluation of the winch joint of a search and rescue helicopter.

Description

Technical Field

[0001] This invention belongs to the field of fatigue testing technology for winch joints of search and rescue helicopters, and specifically relates to a fatigue testing device for electric winch joints of search and rescue helicopters. Background Technology

[0002] With the increasing frequency of natural disasters, there is an urgent need for rescue and relief efforts. Search and rescue helicopters not only possess the inherent capabilities of helicopters, such as vertical takeoff and landing and hovering, but are also equipped with electric / hydraulic winches, medical pods, and other search and rescue equipment, making them crucial rescue and relief tools. The winch, a standard piece of equipment for search and rescue helicopters, is primarily used for the rapid and safe transport of rescue personnel, supplies, and the injured. The winch joint is a critical load-bearing structure of the electric winch, connecting the winch drive system to the wire rope; its stress condition directly affects the safety and reliability of rescue and relief operations.

[0003] During operation, winch joints primarily bear various loads, including axial tension of the wire rope, bending moment generated by wire rope sway, and torque. Their main failure mode is fatigue damage, and the fatigue performance of the winch joint directly determines the service life of the electric winch and search and rescue safety. Therefore, during the development phase of electric winches, simulating real-world usage conditions and stress patterns to conduct fatigue tests on the winch joints and determine their fatigue performance and weak points is crucial. Due to the complex structure of winch joints, no reports have been found regarding fatigue testing loading devices for winch joints to date. Furthermore, the electric winch of a certain search and rescue helicopter is a newly developed product with a winch joint structure different from previous models, making it impossible to provide fatigue performance data based on the service life of other winch joint models. Therefore, there is an urgent need to design a fatigue testing device for helicopter winch joints to guide fatigue testing of search and rescue helicopter electric winches. Summary of the Invention

[0004] Objective: To address the technical requirements of fatigue testing for winch joints in search and rescue helicopters, this invention provides a fatigue testing device capable of simulating complex structural boundary conditions and coordinating the loading of multiple loads. This fatigue testing device simulates the service boundary conditions of the winch joint. Through this fatigue testing loading device, multiple loads, such as axial loads, bending moments, and torques, are effectively transferred to the winch joint while ensuring the accuracy of coordinated loading, thereby achieving the purpose of evaluating the fatigue performance of the winch joint. Finally, experimental results demonstrate that this winch joint fatigue testing device has a stable structure, high testing accuracy, and a total error controllable within 3%. The test results are realistic and accurate, effectively solving the problem of the relative lack of fatigue testing devices for similar complex structural test pieces subjected to multiple loads.

[0005] To address the above-mentioned technical issues, the present invention provides the following technical solution: A fatigue testing device for electric winch joints of search and rescue helicopters, comprising: The bottom fixing plate is fixedly connected to the load-bearing ground rail of the factory building; The test piece boundary simulation frame is fixedly connected to the bottom fixing plate. The winch joint test piece is placed in the test piece boundary simulation frame to simulate the actual use state of the search and rescue helicopter winch joint. A dummy force transmission rod is inserted into the winch joint test piece at one end and fixed by anti-loosening bolts. The loading component has two parallel connections to the force transmission rod dummy, with a certain distance between the two connection points; The bearing shank assembly has three parts, which are respectively connected to the other end of the two loading components and the force transmission rod dummy.

[0006] As a further technical solution of the present invention: 12 bolts pass through 12 through holes on the bottom fixing plate, and the bottom fixing plate is fixed to the factory building bearing rail by nuts; Then, 12 bolts are passed through the 12 through holes on the test piece fixing frame dummy and screwed into the threaded holes on the bottom fixing plate to fix the test piece fixing frame dummy to the bottom fixing plate.

[0007] As a further technical solution of the present invention: the length of each side and the thickness of the inner wall of the test piece boundary simulation frame are different. The winch joint test piece is gently placed into the test piece boundary simulation frame according to its shape and size, and the two are assembled together by rivets. If there is a gap at the joint, a peelable gasket can be added to eliminate the gap.

[0008] As a further technical solution of the present invention: the dummy force transmission rod is gently passed through the two inner holes of the winch joint to prevent damage to the test piece, so that the protruding shoulder plane of the dummy force transmission rod is in contact with the upper point plane of the winch joint, and the anti-loosening bolt is passed through the inner hole of the protruding shoulder plane of the dummy force transmission rod and screwed into the threaded hole of the upper point of the winch joint to assemble the winch joint and the dummy force transmission rod together, and the safety pin is locked.

[0009] As a further technical solution of the present invention: a first mounting part and a second mounting part are provided on the force transmission rod dummy, and two loading components are respectively connected to the first mounting part and the second mounting part.

[0010] As a further technical solution of the present invention: a threaded rod end of a loading component is passed through the inner hole of the second mounting part and locked by a washer, a spring washer and a nut; a bolt is passed through two bushing holes of the loading component and connected to the third bearing shank assembly, and the third bearing shank assembly is connected to the actuating cylinder and the sensor to apply a vertical load F3.

[0011] As a further technical solution of the present invention: the threaded rod end of another loading component passes through the inner hole of the first mounting part and the bearing inner hole of the first bearing shank assembly, and the force transmission rod dummy, the loading component, and the first bearing shank assembly are assembled together, and the threaded rod end of the loading component is locked with a washer, a spring washer, and a nut. The loading assembly is assembled with the first bearing shank assembly, the actuating cylinder, and the sensor to apply a vertical load F1; The two vertical loads are of different magnitudes and opposite directions, thus forming bending moment load and torque load acting on the winch joint test specimen.

[0012] As a further technical solution of the present invention: the second bearing shank assembly is assembled with the actuating cylinder and the sensor to apply an axial load F2, which ultimately forms a variety of loads on the winch joint, including axial load, bending moment load and torque load.

[0013] As a further technical solution of the present invention: the spacing between the groove of the force transmission rod dummy and the two bushings of the loading assembly is the same, so that the same bearing shank assembly is used to connect the sensor in both the axial loading device and the vertical loading device.

[0014] In summary, the beneficial effects of the present invention are as follows: 1. This invention effectively ensures the accuracy of its boundary simulation while maintaining consistency with actual usage conditions, providing effective data support for the structural design and improvement of search and rescue helicopter winch joints, as well as their lifespan assessment. This testing apparatus can meet the fatigue testing requirements for joints of all similar structures.

[0015] 2. This invention can meet the coordinated loading of various fatigue loads such as axial, bending moment, and torque of the winch joint, and accurately simulate the boundary conditions and load characteristics of the winch joint of the search and rescue helicopter. It effectively solves the problem of the lack of domestic fatigue testing equipment for winch joints of search and rescue helicopters, fills the gap in domestic fatigue strength testing technology for winch joints of search and rescue helicopters, and provides data support for further improving the safety and reliability of search and rescue helicopters in performing missions.

[0016] 3. Using this fatigue testing device to conduct fatigue tests on winch joints results in high test accuracy, high overlap between load feedback data and command data, and the total error can be controlled within 3%, ensuring the test results are true and accurate.

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is an isometric view of the assembly of a fatigue testing device for an electric winch joint of a search and rescue helicopter according to the present invention.

[0019] Figure 2 This is a schematic diagram of the bottom fixing plate of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the fixed frame dummy of the test piece of the present invention.

[0021] Figure 4This is a schematic diagram of the assembly of the test piece fixing frame dummy and the electric winch connector of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of the force transmission rod dummy of the present invention.

[0023] Figure 6 This is a schematic diagram of the anti-loosening bolt of the present invention.

[0024] Figure 7 This is an assembly diagram of the force transmission rod dummy and the electric winch connector of the present invention.

[0025] Figure 8 This is a schematic diagram of the structure of the loading component of the present invention.

[0026] Figure 9 This is a schematic diagram of the bearing shank assembly of the present invention.

[0027] Figure 10 This is an assembly diagram of the loading component and bearing shank component of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below with reference to the accompanying drawings.

[0029] In the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present invention.

[0030] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] The following is in conjunction with the appendix Figure 1-10 The embodiments of the present invention will be described in detail below.

[0032] Example 1 This invention discloses a fatigue testing device for the joint of an electric winch on a search and rescue helicopter, comprising: The bottom fixing plate is fixedly connected to the load-bearing ground rail of the factory building; The test piece boundary simulation frame is fixedly connected to the bottom fixing plate. The winch joint test piece is placed in the test piece boundary simulation frame to simulate the actual use state of the search and rescue helicopter winch joint. A dummy force transmission rod is inserted into the winch joint test piece at one end and fixed by anti-loosening bolts. The loading component has two parallel connections to the force transmission rod dummy, with a certain distance between the two connection points; The bearing shank assembly has three parts, which are respectively connected to the other end of the two loading components and the force transmission rod dummy.

[0033] Furthermore, 12 bolts pass through 12 through holes on the bottom fixing plate, and the bottom fixing plate is fixed to the factory's load-bearing ground rail with nuts; Then, 12 bolts are passed through the 12 through holes on the test piece fixing frame dummy and screwed into the threaded holes on the bottom fixing plate to fix the test piece fixing frame dummy to the bottom fixing plate.

[0034] Furthermore, the length of each side and the thickness of the inner wall of the test piece boundary simulation frame are different. The winch joint test piece is gently placed into the test piece boundary simulation frame according to its shape and size, and the two are assembled together by rivets. If there is a gap at the joint, a peelable gasket can be added to eliminate the gap.

[0035] Furthermore, gently pass the dummy force transmission rod through the two inner holes of the winch connector to prevent damage to the test piece, so that the protruding shoulder plane of the dummy force transmission rod fits into the upper point plane of the winch connector. Then, through the inner hole of the protruding shoulder plane of the dummy force transmission rod, screw it into the threaded hole of the upper point of the winch connector to assemble the winch connector and the dummy force transmission rod together, and lock the safety pin.

[0036] Furthermore, a first mounting part and a second mounting part are provided on the force transmission rod dummy, and two loading components are respectively connected to the first mounting part and the second mounting part.

[0037] Furthermore, the threaded end of a loading component is passed through the inner hole of the second mounting part and locked by a washer, spring washer, and nut; the loading component is connected to the third bearing shank assembly by bolts passing through the two bushing holes. The third bearing shank assembly connects the actuating cylinder and the sensor to apply the vertical load F3.

[0038] Furthermore, the threaded rod end of another loading component is passed through the inner hole of the first mounting part and the inner hole of the bearing of the first bearing shank assembly, and the force transmission rod dummy, the loading component, and the first bearing shank assembly are assembled together, and the threaded rod end of the loading component is locked with a washer, a spring washer, and a nut. The loading assembly is assembled with the first bearing shank assembly, the actuating cylinder, and the sensor to apply a vertical load F1; The two vertical loads are of different magnitudes and opposite directions, thus forming bending moment load and torque load acting on the winch joint test specimen.

[0039] Furthermore, the second bearing shank assembly is assembled with the actuating cylinder and sensor to apply an axial load F2, ultimately forming multiple loads on the winch joint, including axial load, bending moment load, and torque load.

[0040] Furthermore, the spacing between the groove of the force transmission rod dummy and the two bushings of the loading assembly is the same, so that the same bearing shank assembly is used to connect to the sensor in both the axial loading device and the vertical loading device.

[0041] To address the fatigue testing requirements of winch joints for search and rescue helicopters, a fatigue testing device is provided that can simulate complex structural boundary conditions and coordinate the loading of multiple loads. This device simulates the service boundary conditions of the winch joint, effectively transferring various loads such as axial, bending moment, and torque to the winch joint while ensuring the accuracy of coordinated loading, thereby achieving the purpose of evaluating the fatigue performance of the winch joint. Finally, experiments demonstrate that the winch joint fatigue testing device is structurally stable, has high testing accuracy, and the total error can be controlled within 3%. The test results are realistic and accurate, effectively solving the problem of the relative lack of fatigue testing devices for similar complex structural test pieces subjected to multiple loads.

[0042] The overall technical solution of the present invention is as follows: The winch joint fatigue testing device is designed with a bottom fixing plate 1, a test piece boundary simulation frame 2, a force transmission rod dummy 3, an anti-loosening bolt 4, a loading assembly 5, a bearing shank assembly 6, an axial loading mechanism, and a vertical loading mechanism, etc., and the test load is applied by an actuating cylinder.

[0043] Key features of this invention include: 1. To realistically simulate the usage boundary of the winch joint, a test piece boundary simulation frame 2 is designed. This frame is composed of irregular polygons, and the thickness of each frame is designed to vary depending on the usage boundary, specifically 10mm, 5mm, 10mm, 6mm, 7mm, 4mm, and 4mm. The winch joint test piece is fixed inside the test piece boundary simulation frame 2 using rivets, the specifications of which are selected based on the thickness of the test piece and the test piece boundary simulation frame 2.

[0044] 2. To accurately achieve the target load on the winch joint test piece, this invention designs a force transmission rod dummy 3. The key to this force transmission rod dummy is to ensure both the assembly relationship with the test piece and sufficient strength to transmit different types of loads. Therefore, one end of the force transmission rod dummy 3 simulates the actual fit of the winch joint, and the other end is connected to the loading assembly 5 and the bearing shank assembly 6 through a groove or other structure designed on the force transmission rod dummy. During the test, test loads in three directions are applied to the force transmission rod dummy 2 through two sets of vertical loading assemblies 5 and bearing shank assemblies 6, and then transmitted to the winch joint. Among them, the vertical loads F1 and F3 are in opposite directions, forming a torsional load applied to the winch joint of the test piece. At the same time, the vertical loads F1 and F3 are unequal in magnitude, and the difference between the two forms a bending moment load on the winch joint. During the test, the specified test load is applied through the extension and retraction movement of the actuating cylinder, thereby satisfying the axial, bending moment, and torque loads required by the test.

[0045] Tests have proven that the winch joint fatigue testing device is structurally stable and can apply the required axial, vertical, and bending moment loads to the winch joint under simulated real boundary conditions.

[0046] Example 2 This invention discloses a fatigue testing device for an electric winch joint of a search and rescue helicopter. First, 12 bolts pass through 12 through holes 1-1 on the bottom fixing plate 1. Nuts are used to fix the bottom fixing plate 1 to the bearing rail of the factory building. Then, 12 bolts pass through 12 through holes 2-1 on the test piece fixing frame dummy 2 and are screwed into the threaded holes 1-2 on the bottom fixing plate, fixing the test piece fixing frame dummy 2 to the bottom fixing plate 1. Simulating the actual use of the search and rescue helicopter winch joint, the polygonal test piece boundary simulation frame is designed with different side lengths and inner wall thicknesses 2-2. The winch joint test piece is gently placed into the test piece boundary simulation frame body 2-3 according to its shape and size, and the two are assembled together with rivets. If there is a gap at the joint, a peelable gasket can be added to eliminate the gap. The assembled winch joint test piece and the test piece boundary simulation frame are as follows: Figure 4 As shown. Gently pass the dummy force transmission rod 3 through the two inner holes of the winch connector to prevent damage to the test piece, ensuring that the shoulder plane 3-3 of the dummy force transmission rod aligns with the upper point plane of the winch connector. Then, pass the anti-loosening bolt 4 through the inner hole 3-4 of the shoulder plane of the dummy force transmission rod 3 and screw it into the threaded hole at the upper point of the winch connector, assembling the winch connector and the dummy force transmission rod 3 together, and lock the safety pin. The isometric view of the assembled dummy force transmission rod 3 and winch connector is shown below. Figure 7 As shown. The threaded end 5-1 of the vertical loading assembly is passed through the inner hole 3-5 of the force transmission rod dummy and tightened with washers, spring washers, and nuts to prevent loosening during the test. Bolts are then passed through the two bushing holes 5-2 of the vertical loading assembly and connected to the bearing shank assembly 6. The isometric view of the assembled force transmission rod dummy 3, loading assembly 5, and bearing shank assembly 6 is shown below. Figure 10 As shown, the bearing shank assembly 6 connects the actuator cylinder and sensor to apply a vertical load F3. The threaded end 5-1 of another vertical loading assembly passes through the inner hole 3-7 of the force transmission rod dummy and the bearing inner hole 6-2 of the bearing shank assembly. The force transmission rod dummy 3, loading assembly 5, and bearing shank assembly 6 are assembled together. The threaded end 5-1 of the vertical loading assembly is secured with washers, spring washers, and nuts to prevent loosening during the test. The vertical loading assembly 5, assembled with the bearing shank assembly 6, actuator cylinder, and sensor, applies a vertical load F1. The two vertical loads are unequal in magnitude and opposite in direction, thus forming bending moment and torque loads acting on the winch joint test piece. The bearing shank assembly 6, assembled with the actuator cylinder and sensor, applies an axial load F2, ultimately forming multiple loads on the winch joint, including axial load, bending moment load, and torque load.

[0047] The main features of this device are: (1) The test device is simple and easy to disassemble, and the test fixtures can be used for each other. The spacing between the groove 3-6 of the force transmission rod dummy and the two bushings 5-2 of the loading component is the same, so that the same bearing shank assembly 6 is used to connect the sensor in both the axial loading device and the vertical loading device, thereby reducing the processing steps of the fixture, improving the test efficiency, and improving the reusability of the fixture; (2) By applying two vertical loads of opposite directions and different sizes on the force transmission rod dummy, the bending moment and torque loads are formed on the winch joint test piece. The design method is simple, the internal force balance of the system is realized, and the stability of the test bench is improved.

[0048] In summary, this test device can accurately simulate the installation boundary and load conditions of the search and rescue helicopter winch joint on the electric winch, meeting the fatigue test requirements of the search and rescue helicopter electric winch joint. It has an ingenious structural design, stable and reliable working performance, good adjustability, and is easy to install and disassemble. The total test error can be controlled within 3%, which can fully verify the fatigue performance of the search and rescue helicopter winch joint, thus providing a basis for determining the service life and weak points of the winch joint.

[0049] Thus, the objective of this invention has been achieved.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fatigue testing device for the joint of an electric winch on a search and rescue helicopter, characterized in that, include: The bottom fixing plate is fixedly connected to the load-bearing ground rail of the factory building; The test piece boundary simulation frame is fixedly connected to the bottom fixing plate. The winch joint test piece is placed in the test piece boundary simulation frame to simulate the actual use state of the search and rescue helicopter winch joint. A dummy force transmission rod is inserted into the winch joint test piece at one end and fixed by anti-loosening bolts. The loading component has two parallel connections to the force transmission rod dummy, with a certain distance between the two connection points; The bearing shank assembly has three parts, which are respectively connected to the other end of the two loading components and the force transmission rod dummy.

2. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 1, characterized in that, Twelve bolts pass through twelve through holes in the bottom fixing plate, and the bottom fixing plate is fixed to the load-bearing ground rail of the factory building with nuts; Then, 12 bolts are passed through the 12 through holes on the test piece fixing frame dummy and screwed into the threaded holes on the bottom fixing plate to fix the test piece fixing frame dummy to the bottom fixing plate.

3. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 1, characterized in that, The length and inner wall thickness of each side of the test specimen boundary simulation frame are different. The winch joint test specimen is gently placed into the test specimen boundary simulation frame according to its shape and size, and the two are assembled together by rivets. If there is a gap at the joint, a peelable gasket can be added to eliminate the gap.

4. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 1, characterized in that, Gently pass the dummy force transmission rod through the two inner holes of the winch connector to prevent damage to the test piece. Make sure the shoulder plane of the dummy force transmission rod fits against the upper point plane of the winch connector. Then, pass the anti-loosening bolt through the inner hole of the shoulder plane of the dummy force transmission rod and screw it into the threaded hole at the upper point of the winch connector to assemble the winch connector and the dummy force transmission rod together. Finally, lock the safety pin.

5. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 4, characterized in that, The force transmission rod dummy is provided with a first mounting part and a second mounting part, and two loading components are respectively connected to the first mounting part and the second mounting part.

6. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 5, characterized in that, A threaded rod end of a loading component is passed through the inner hole of the second mounting part and locked with a washer, spring washer, and nut; it is connected to the third bearing shank assembly by bolts passing through the two bushing holes of the loading component. The third bearing shank assembly connects the actuating cylinder and the sensor to apply the vertical load F3.

7. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 6, characterized in that, Pass the threaded rod end of another loading component through the inner hole of the first mounting part and the inner hole of the bearing of the first bearing shank assembly, and assemble the force transmission rod dummy, the loading component, and the first bearing shank assembly together. The threaded rod end of the loading component is locked with a washer, a spring washer, and a nut. The loading assembly is assembled with the first bearing shank assembly, the actuating cylinder, and the sensor to apply a vertical load F1; The two vertical loads are of different magnitudes and opposite directions, thus forming bending moment load and torque load acting on the winch joint test specimen.

8. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 7, characterized in that, The second bearing shank assembly is assembled with the actuating cylinder and sensor to apply an axial load F2, ultimately forming multiple loads on the winch joint, including axial load, bending moment load, and torque load.

9. The fatigue testing device for the electric winch joint of a search and rescue helicopter according to claim 8, characterized in that, The spacing between the groove of the force transmission rod dummy and the two bushings of the loading assembly is the same, so that the same bearing shank assembly is used to connect to the sensor in both the axial loading device and the vertical loading device.

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