Helicopter nose landing gear fatigue test device and method

Abstract

The invention provides a helicopter nose landing gear fatigue test device, and the device comprises a bottom plate which is connected and fixed to a ground grooved rail; the fixed connecting plate is fixed on the bottom plate through a bolt; wherein the lower end connecting structure of the test piece is of a square structure, the periphery of the lower end connecting structure is connected to the fixed connecting plate through rivets, and the airplane wheel fake part assemblies are arranged on the two sides of the upper end connecting structure of the test piece. One end of the loading double-fork lug is connected with the airplane wheel fake part assembly; the torsion-proof bolt is connected with the airplane wheel fake part assembly; one end of the loading single fork ear is connected with the other end of the loading double fork ear; the servo actuation loading mechanism is connected with the other end of the loading single fork lug; wherein the servo actuation loading mechanism is used for realizing loading in the heading direction, the lateral direction and the vertical direction; meanwhile, the invention further provides a helicopter nose landing gear fatigue test method.

Description

Technical Field

[0001] This application belongs to the technical field of helicopter fatigue testing, and particularly relates to a fatigue testing device and method for a helicopter nose landing gear. Background Art

[0002] The landing gear is an important part of the helicopter structure. The landing gear is the helicopter landing device and absorbs the energy during the helicopter landing process, which can reduce the impact on the helicopter during landing. The helicopter nose landing gear and its connected upper joint mainly bear the gravity of the front fuselage during the aircraft landing process and the heading and lateral loads during the taxiing process. In order to explore the fatigue performance and weak parts of the helicopter nose landing gear and its connection fatigue test, it is necessary to carry out the fatigue test of the helicopter nose landing gear and its connection.

[0003] At present, there is a lack of a fatigue testing device for the helicopter nose landing gear and its connected upper joint. Therefore, the present invention designs a fatigue testing device for the helicopter nose landing gear and its connected upper joint. Summary of the Invention

[0004] Object of the Invention: Design a fatigue testing device for a helicopter nose landing gear and its connected upper joint, so as to achieve the purpose of solving the lack of a fatigue testing device for the helicopter nose landing gear and its connected upper joint and exploring the fatigue performance of the helicopter nose landing gear and its connected upper joint.

[0005] In a first aspect, the present application provides a fatigue testing device for a helicopter nose landing gear, and the device includes:

[0006] A bottom plate, connected to and fixed on a ground trough rail;

[0007] A fixed connection plate, fixed to the bottom plate by bolts; wherein, the lower connection structure of the test piece is a square structure, and the four sides are connected to the fixed connection plate by rivets.

[0008] A wheel dummy component, arranged on both sides of the upper connection structure of the test piece;

[0009] A loading double fork ear, one end of which is connected to the wheel dummy component;

[0010] An anti-twist bolt, connected to the wheel dummy component;

[0011] A loading single fork ear, one end of which is connected to the other end of the loading double fork ear;

[0012] A servo actuator loading mechanism, connected to the other end of the loading single fork ear; wherein, the servo actuator loading mechanism is used to achieve loading in three directions of heading, lateral, and vertical.

[0013] Preferably, the test piece is the nose landing gear and the upper joint connected thereto.

[0014] Preferably, the wheel dummy component includes two circular plates, seven connecting bolts, an intermediate connecting rod, two lock nuts and washers, an intermediate sleeve, and long and short sleeves on the connecting bolts.

[0015] Preferably, eight bolt holes are machined on the outer side of the circular plate for connecting seven connecting bolts and the loading double fork ear;

[0016] Among them, two short sleeves and a loading single fork ear are respectively connected between the bolt holes at the uppermost and frontmost positions of the two circular plates. The loading single fork ear is located between the two short sleeves. The outer side surfaces of the two sleeves are in contact with the inner side surfaces of the circular plates. The outer side at the uppermost position of the circular plate is connected and fixed through the loading double fork ear, and the rest are connected and fixed through the connecting bolts.

[0017] Preferably, the loading double fork ear is connected to the loading single fork ear through a bolt, so as to realize the loading in the three directions of X, Y, and Z acting on the wheel dummy component, and then transfer the load to the test piece through the wheel dummy component.

[0018] Preferably, the intermediate connecting rod is of a cylindrical structure, and a hole is machined on the inner side along the axis to be connected to the test piece rod; a radial hole is machined at the front end of the intermediate connecting rod and connected to the test piece through an anti-torsion bolt to prevent relative rotation during the test loading process. Four key structures are also machined on the intermediate connecting rod to match the key grooves of the two circular plates. Washers are connected to the outside of the center positions of the two circular plates and tightened with lock nuts.

[0019] Preferably, the four key structures machined on the intermediate connecting rod also prevent the relative rotation between the intermediate connecting rod and the circular plate, so as to effectively transfer the load.

[0020] In a second aspect, the present application also provides a fatigue test method for a helicopter nose landing gear, and the method includes:

[0021] Step 1: The wheel dummy component is connected to the holes designed on the loading double fork ear. The machining position is designed according to the position of the compression amount when the tire contacts the ground surface, and the vertical load is applied at the center along the line connecting the center of the circular plate. The lateral load is transmitted on the loading single fork ear connected to the outside of the loading double fork ear. Two loading single fork ears are connected in the middle of the two circular plates in the wheel dummy component, which are in the horizontal and vertical directions respectively. The loading single fork ear connected in the vertical direction transmits the vertical load, and the loading single fork ear connected in the horizontal direction transmits the course load; the distance between the outer side surfaces of the two circular plates connected by the wheel dummy component simulates the tire width to ensure that the loading load acts on the real position of the test piece;

[0022] Step 2: Install the test piece. During the installation process, first, the lower connection structure of the test piece is riveted and fixed to the fixed connection plate. The fixed connection plate is fixed to the bottom plate through bolts, and the bottom plate is connected to and fixed on the ground track. The nose landing gear and the upper joint test piece connected thereto are of a dual-tire structure. The loading structure at the upper end of the test piece also needs to be designed to simulate the dual-tire structure. The two sides of the loading structure at the upper end of the test piece are connected with the wheel dummy assembly and the loading double fork ear, anti-twist bolts, and the loading single fork ear. The loading single fork ear is connected to the servo loading mechanism. The servo loading mechanism applies loads in three directions to the loading single fork ear. The loading single fork ear transfers the lateral load to the loading double fork ear, and the double fork ear applies the vertical load to the circular plate of the wheel dummy assembly. The vertical and course loads are applied by the servo loading mechanism to the circular plate of the wheel dummy assembly through the loading single fork ear, and the circular plate then transfers the three-direction load to the intermediate connecting rod. The inner cylindrical surface of the intermediate connecting rod is connected to the tire connecting shaft rod of the test piece, and the three-direction load is applied to the test piece.

[0023] Step 3: Install the test piece according to Step 2. After the installation is completed, enter the debugging process. Debug the three-direction loading load. The debugging load is increased gradually from small to large until the load requirement is met. And by collecting the corresponding test data and analyzing the test data, ensure that the loading error meets within 3%.

[0024] Step 4: After the debugging load meets the test load, enter the fatigue test. Design the protection limit and test error in the control system. During the test process, observe the load and test conditions on the test piece according to the inspection requirements of the test requirements, and terminate the test with reference to the test termination conditions.

[0025] The present application has the following technical effects:

[0026] The present invention designs a fatigue test device for a helicopter nose landing gear and its connection. The device is simple and practical, with relatively low processing and maintenance costs, solves the problem of the lack of a fatigue test device for the nose landing gear and its connection, has a stable loading waveform, and the error does not exceed 3%. Using the device of the present invention, three loads in the course, lateral, and vertical directions can be applied to the nose landing gear and its connection, simulating the helicopter landing and ground states, obtaining the fatigue performance and failure parts of the nose landing gear and its connection under the action of three-direction loads, and providing reliable data support for guiding the design of the nose landing gear and its connection of helicopter structural parts. Description of the Drawings

[0027] Figure 1 is an isometric view of the fatigue test device for a helicopter nose landing gear and its connection provided by an embodiment of the present application;

[0028] Figure 2 is a front isometric view of the wheel dummy assembly provided by an embodiment of the present application;

[0029] Figure 3It is an isometric view from the side of the wheel dummy component provided by an embodiment of the present application;

[0030] Figure 4 It is an isometric view of the wheel dummy component provided by an embodiment of the present application with one circular plate hidden;

[0031] Figure 5 It is an isometric view of the circular plate provided by an embodiment of the present application;

[0032] Figure 6 It is an isometric view of the intermediate connecting rod provided by an embodiment of the present application;

[0033] Figure 7 It is an isometric view of the intermediate sleeve provided by an embodiment of the present application. Detailed implementation manners

[0034] Please refer to Figures 1-7 , this device simulates the connection and loading forms of the helicopter nose landing gear and its connected upper joint on the helicopter. It has a simple structure and is easy to install. Using this device can fully evaluate the fatigue performance and failure modes of the nose landing gear and its connected upper joint under simulated helicopter landing and ground conditions, providing data support for the design of helicopter structural components.

[0035] As Figure 1 shown, the present invention designs a fatigue test device for a helicopter nose landing gear and its connected upper joint. The device mainly includes: a wheel dummy component 1, a test piece 2, a fixed connecting plate 3, a bottom plate 4, a loading double fork ear 5, an anti-torsion bolt 6, a loading single fork ear 7 and other components.

[0036] As Figure 1 shown, the test piece 2 (i.e., the nose landing gear and its connected upper joint) is divided into an upper end loading structure and a lower end connecting structure. The upper end loading structure of the test piece 2 consists of one wheel dummy component 1, a loading double fork ear 5, an anti-torsion bolt 6, and a loading single fork ear 7 on each side for centering. Among them, the loading single fork ear 7 of the upper end loading structure of the test piece 2 is connected to the servo actuator loading mechanism to achieve loading in three directions: heading, lateral, and vertical. The lower end connecting structure of the test piece 2 is a square structure, and the four sides are connected and fixed to the fixed connecting plate 3 by rivets. The fixed connecting plate 3 is fixed to the bottom plate 4 by bolts, and the bottom plate 4 is connected to and fixed on the ground track.

[0037] As Figure 2 , Figure 3 and Figure 4 shown, the wheel dummy component 1 includes two circular plates 101, seven connecting bolts 103, an intermediate connecting rod 102, two jam nuts 104 and washers 105, an intermediate sleeve 107, and a long sleeve 108 and a short sleeve 106 on the connecting bolt 103.

[0038] As shown in the figure, eight bolt holes are machined on the outer side of the circular plate Figure 5 to connect seven connecting bolts 103 and the loading double fork ear 5. Among them, two short sleeves 106 and one loading single fork ear 7 are respectively connected between the bolt holes at the uppermost and frontmost positions of the two circular plates 101. The loading single fork ear 7 is located between the two short sleeves 106. The outer sides of the two sleeves 106 are in contact with the inner side of the circular plate 101. The upper outer side of the circular plate 101 is fixedly connected through the loading double fork ear 5, and the rest are fixedly connected through the connecting bolts 103. The loading double fork ear 5 is connected to the loading single fork ear 7 through bolts, so as to realize the loading in the X, Y, and Z directions acting on the wheel dummy assembly 1, and then transfer the load to the test piece through the wheel dummy assembly 1.

[0039] The main structures at the central position of the wheel dummy assembly 1 include the intermediate connecting rod 102, the lock nut 104, the washer 105, and the intermediate sleeve 107. The intermediate sleeve 107 is as shown in Figure 7 the figure. Among them, the intermediate connecting rod 102 is a cylindrical structure, as shown in Figure 6 the figure. A hole is machined on the inner side along the axial direction to be connected with the rod of the test piece 2. A radial hole is machined at the front end of the intermediate connecting rod 102 and is connected to the test piece 2 through the anti-twist bolt 6 to prevent mutual rotation during the test loading process. Four key structures are also machined on the intermediate connecting rod 102 to match the key grooves of the two circular plates 101. A washer 105 is connected to the outside of the central position of the two circular plates 101 and is tightened by the lock nut 104. The four key structures machined on the intermediate connecting rod 102 also prevent the intermediate connecting rod 102 from rotating with the circular plate 101, so as to effectively transfer the load.

[0040] In other embodiments of the present application, for the three kinds of loads of heading, lateral, and vertical directions provided, the process of the test method is as follows:

[0041] Step 1, as shown in Figure 2 and Figure 3 the figure, the wheel dummy assembly 1 is connected to the holes designed on the loading double fork ear 5. The machining position is designed according to the position of the compression amount when the tire contacts the ground, and the load is applied vertically downward on the line connecting the center and the center of the circular plate. The lateral load is transmitted on the loading single fork ear 7 connected to the outside of the loading double fork ear 5. Two loading single fork ears 7 are connected between the two circular plates 101 in the wheel dummy assembly 1, which are respectively in the horizontal and vertical directions. The loading single fork ear 7 connected in the vertical direction transmits the vertical load, and the loading single fork ear 7 connected in the horizontal direction transmits the heading load. The distance between the outer sides of the two circular plates 101 connected by the wheel dummy assembly 1 simulates the tire width to ensure that the loading load acts on the real position of the test piece.

[0042] Step 2: Install the test piece. During the installation process, first, the lower connection structure of the test piece 2 is riveted and fixed to the fixed connection plate 3. The fixed connection plate 3 is fixed to the bottom plate 4 by bolts. The bottom plate 4 is connected to and fixed on the ground track. The front landing gear and the upper joint test piece connected thereto are of a dual-tire structure. The upper loading structure of the test piece 2 also needs to be designed to simulate the dual-tire structure. The two sides of the upper loading structure of the test piece 2 are connected to the wheel dummy assembly 1, the loading double fork ear 5, the anti-twist bolt 6, and the loading single fork ear 7. The loading single fork ear 7 is connected to the servo loading mechanism. The servo loading mechanism applies loads in three directions to the loading single fork ear 7. The loading single fork ear 7 transfers the lateral load to the loading double fork ear 5. The double fork ear 5 applies the vertical load to the circular plate 101 of the wheel dummy assembly 1. The vertical and course loads are applied by the servo loading mechanism to the circular plate 101 of the wheel dummy assembly 1 through the loading single fork ear 7. The circular plate 101 then transfers the three-way load to the intermediate connecting rod 102. The inner cylindrical surface of the intermediate connecting rod 102 is connected to the test piece tire connecting shaft rod, and the three-way load is applied to the test piece.

[0043] Step 3: Install the test piece according to Step 2. After the installation is completed, enter the debugging stage. Debug the three-way loading load. The debugging load is increased gradually from small to large until the load requirement is met. And by collecting the corresponding test data and analyzing the test data, ensure that the loading error meets within 3%.

[0044] Step 4: After the debugging load meets the test load, enter the fatigue test. Design the protection limit and test error in the control system. During the test process, observe the load and test conditions on the test piece according to the inspection requirements of the test requirements. Refer to the test termination conditions to terminate the test.

[0045] The present invention designs a fatigue test device for a helicopter front landing gear and its connected upper joint. The device mainly includes components such as the wheel dummy assembly 1, the test piece 2, the fixed connection plate 3, the bottom plate 4, the loading double fork ear 5, the anti-twist bolt 6, and the loading single fork ear 7.

[0046] Among them, the test piece 2 (i.e., the front landing gear and its connected upper joint) is divided into an upper loading structure and a lower connection structure. The upper loading structure of the test piece 2 has one wheel dummy assembly 1, a loading double fork ear 5, an anti-twist bolt 6, and a loading single fork ear 7 on each side for centering. The loading single fork ear 7 of the upper loading structure of the test piece 2 is connected to the servo actuation loading mechanism to achieve loading in three directions of course, lateral, and vertical. The lower connection structure of the test piece 2 is a square structure, and the four sides are riveted and fixed to the fixed connection plate 3. The fixed connection plate 3 is fixed to the bottom plate 4 by bolts. The bottom plate 4 is connected to and fixed on the ground track.

[0047] Among them, the wheel dummy component 1 includes two circular plates 101, seven connecting bolts 103, an intermediate connecting rod 102, two lock nuts 104 and washers 105, an intermediate sleeve 107, and a long sleeve 108 and a short sleeve 106 on the connecting bolt 103.

[0048] Among them, eight bolt holes are machined on the outer side of the circular plate 101 for connecting seven connecting bolts 103 and the loading double fork ear 5. Among them, two short sleeves 106 and a loading single fork ear 7 are respectively connected between the bolt holes at the uppermost and frontmost positions of the two circular plates 101. The loading single fork ear 7 is located between the two short sleeves 106, and the outer sides of the two sleeves 106 are in contact with the inner side of the circular plate 101. The outer side at the uppermost position of the circular plate 101 is fixedly connected through the loading double fork ear 5, and the rest are fixedly connected through the connecting bolts 103. The loading double fork ear 5 is connected to the loading single fork ear 7 through bolts, so as to realize the loading in three directions of heading, lateral, and vertical acting on the wheel dummy component 1, and transfer the load to the test piece through the wheel dummy component 1.

[0049] Among them, the main structures at the central position of the wheel dummy component 1 are the intermediate connecting rod 102, lock nuts 104, washers 105 and an intermediate sleeve 107. Among them, the intermediate connecting rod 102 is a cylindrical structure, and a hole is machined along the axial inner side to be connected with the rod of the test piece 2. A radial hole is machined at the front end of the intermediate connecting rod 102 and is connected to the test piece 2 through an anti-twist bolt 6 to prevent relative rotation during the test loading process. Four key structures are also machined on the intermediate connecting rod 102 to match the key grooves of the two circular plates 101. A washer 105 is connected to the outer side at the central position of the two circular plates 101 and tightened by a lock nut 104. The four key structures machined on the intermediate connecting rod 102 also prevent relative rotation between the intermediate connecting rod 102 and the circular plate 101, so as to effectively transfer the load.

Claims

1. A fatigue test device for the front landing gear of a helicopter, characterized in that, The device includes: A bottom plate, which is connected to and fixed on the ground channel rail; A fixed connecting plate, which is fixed to the bottom plate by bolts; wherein, the lower end connecting structure of the test piece is a square structure, and the four sides are connected to the fixed connecting plate by rivets. A wheel dummy component, which is arranged on both sides of the upper end connecting structure of the test piece; A loading double fork ear, one end of which is connected to the wheel dummy component; An anti-twist bolt, which is connected to the wheel dummy component; A loading single fork ear, one end of which is connected to the other end of the loading double fork ear; A servo-actuated loading mechanism, which is connected to the other end of the loading single fork ear; wherein, the servo-actuated loading mechanism is used to realize loading in three directions: heading, lateral and vertical.

2. The device according to claim 1, characterized in that, The test piece is the front landing gear and its connected upper joint.

3. The device according to claim 1, characterized in that, The wheel dummy component includes two circular plates, seven connecting bolts, an intermediate connecting rod, two lock nuts and washers, an intermediate sleeve, and long and short sleeves on the connecting bolts.

4. The device according to claim 3, characterized in that Eight bolt holes are machined on the outer side of the circular plate for connecting seven connecting bolts and the loading double fork ear; Wherein, the bolt holes at the uppermost and foremost positions of the two circular plates are respectively connected with two short sleeves and a loading single fork ear. The loading single fork ear is located between the two short sleeves. The outer side surfaces of the two sleeves are in contact with the inner side surfaces of the circular plates. The outer side of the uppermost part of the circular plate is connected and fixed through the loading double fork ear, and the rest are connected and fixed through connecting bolts.

5. The device according to claim 4, characterized in that, The loading double fork ear is connected to the loading single fork ear through bolts, so as to realize loading in three directions of X, Y, and Z acting on the wheel dummy component, and then transfer the load to the test piece through the wheel dummy component.

6. The device according to claim 5, wherein The intermediate connecting rod is of a cylindrical structure, and a hole is machined on the inner side along the axial direction to be connected with the rod of the test piece; a radial hole is machined at the front end of the intermediate connecting rod and connected to the test piece through an anti-twist bolt to prevent relative rotation during the test loading process. Four key structures are also machined on the intermediate connecting rod to match the key grooves of the two circular plates. Washers are connected to the outer sides of the centers of the two circular plates and tightened with lock nuts.

7. The device according to claim 6, characterized in that, Four key structures are also machined on the intermediate connecting rod to prevent relative rotation between the intermediate connecting rod and the circular plate, so as to effectively transfer the load.

8. A fatigue test method for the front landing gear of a helicopter, characterized in that, The method includes: Step 1, the holes designed for connecting the loading double fork ear of the wheel dummy component are machined at positions according to the compression amount when the tire contacts the ground surface, and the loading is applied vertically downward along the line connecting the center and the center of the circular plate. The lateral load is transmitted on the loading single fork ear connected to the outer side of the loading double fork ear. Two loading single fork ears are connected in the middle of the two circular plates in the wheel dummy component, which are in the horizontal and vertical directions respectively. The loading single fork ear connected in the vertical direction transmits the vertical load, and the loading single fork ear connected in the horizontal direction transmits the heading load; the distance between the outer side surfaces of the two circular plates connected by the wheel dummy component simulates the tire width to ensure that the loading load acts on the real position of the test piece. Step 2: Install the test piece. During the installation process, first, the connecting structure at the lower end of the test piece is riveted and fixed to the fixed connecting plate. The fixed connecting plate is fixed to the bottom plate through bolts, and the bottom plate is connected to and fixed on the ground trough rail; the front landing gear and the upper joint test piece connected to it are of a dual-tire structure. The loading structure at the upper end of the test piece also needs to be designed to simulate the dual-tire structure. The two sides of the loading structure at the upper end of the test piece are connected with the wheel dummy assembly and the loading double fork ear, anti-twist bolts, and the loading single fork ear. The loading single fork ear is connected to the servo loading mechanism; the servo loading mechanism applies loads in three directions to the loading single fork ear. The loading single fork ear transfers the lateral load to the loading double fork ear, and the double fork ear applies the vertical load to the circular plate of the wheel dummy assembly. The vertical and course loads are applied by the servo loading mechanism to the circular plate of the wheel dummy assembly through the loading single fork ear. The circular plate then transfers the three-direction load to the intermediate connecting rod. The inner cylindrical surface of the intermediate connecting rod is connected to the tire connecting shaft rod of the test piece, and the three-direction load is applied to the test piece; Step 3: Install the test piece according to Step 2. After the installation is completed, enter the debugging stage. Debug the three-direction loading load. The debugging load is increased gradually from small to large until it meets the load requirements. And by collecting the corresponding test data and analyzing the test data, ensure that the loading error meets within 3%; Step 4: After the debugging load meets the test load, enter the fatigue test. Design the protection limit and test error in the control system. During the test process, observe the load and test conditions on the test piece according to the inspection requirements of the test requirements, and terminate the test with reference to the test termination conditions.

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