A rocker arm type landing gear prosthesis

Abstract

The present application relates to a kind of rocker gear force loading dummy, belong to the technical field of aircraft structure strength statics / fatigue test.A kind of rocker gear dummy, its key transmission point coordinate, constraint mode are consistent with real landing gear, structural strength meets the whole cycle requirement of whole machine fatigue test, including main pillar dummy, lower rocker arm dummy, upper arm dummy, main shaft dummy……, also include dummy wheel and fixed support;Dummy wheel includes wheel axle, loading plate, one end of wheel axle is polygonal wheel axle anti-rotation fit section, for transmitting landing gear touch point X direction load, wheel axle anti-rotation fit section is adapted to be opened on lower rocker arm dummy on mounting hole, and with mounting hole insertion, loading plate is set on the other end of wheel axle, and a plurality of loading holes are opened on it;Fixed support is installed in the end of lower rocker arm dummy.The present application has the following advantages: meet the whole cycle of whole machine fatigue test;Can save cost;Realize the functional requirement of rocker gear;Fixed support supports aircraft in static state.

Description

Technical Field

[0001] This invention relates to a rocker arm type landing gear force transmission loading dummy, belonging to the field of aircraft structural strength static / fatigue testing technology. Background Technology

[0002] In full-aircraft fatigue testing, the primary function of the landing gear is to transfer loads, followed by supporting the aircraft. Ensuring that the load transfer path remains unchanged during the load transfer process is of paramount importance; otherwise, the authenticity of the load cannot be guaranteed.

[0003] In a full-aircraft fatigue test of a certain type of trainer aircraft, the aircraft is supported by one nose landing gear and two main landing gears. Ground-spectrum loads are applied to the landing gear simultaneously to assess the fatigue strength and fatigue life of the aircraft structure. However, real landing gear cannot be fitted with support devices and cannot be connected to the loading equipment, making it inconvenient to apply ground-spectrum loads to it. If real landing gear is used for the test, it would also participate in the fatigue test process, potentially leading to fatigue failure of the landing gear before the aircraft structure, thus making the full-aircraft fatigue test impossible.

[0004] In response to the situation where the actual landing gear cannot meet the test requirements in the full-aircraft fatigue test of a certain type of trainer aircraft, it is necessary to design a rocker arm landing gear dummy to support the aircraft. At the same time, ground spectrum loads are applied to the landing gear dummy to assess the fatigue strength and fatigue life of the aircraft structure, ensuring that the strength of the rocker arm landing gear dummy can meet the full-aircraft fatigue test cycle. Summary of the Invention

[0005] The purpose of this invention is to provide a rocker arm landing gear dummy that can stably support the aircraft during the test pause phase, and can accurately and realistically transfer loads from all directions to the aircraft structure during the test, so as to assess the fatigue strength and fatigue life of the aircraft structure.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a rocker arm landing gear dummy, whose key force transmission point coordinates and constraint methods are consistent with those of the real landing gear, and whose structural strength meets the requirements of the full-cycle fatigue test of the entire aircraft, includes a main strut dummy, a lower rocker arm dummy, an upper support arm dummy, a main shaft dummy, a buffer dummy, a retraction actuator dummy, a small strut dummy, and also includes a dummy wheel and a fixed bracket; the dummy wheel includes an axle and a loading plate, one end of the axle is a polygonal axle anti-rotation fitting section, used to transmit the X-direction load of the landing gear contact point, the axle anti-rotation fitting section is adapted to the mounting hole opened on the lower rocker arm dummy and is inserted into the mounting hole, the loading plate is set at the other end of the axle, and has several loading holes for connecting loading equipment; the fixed bracket is installed at the end of the lower rocker arm dummy for supporting the aircraft when static.

[0007] Preferably, the loading holes include a wheel center X-axis loading hole, a wheel center Y-axis loading hole, and a contact point loading hole; each loading hole is fitted with a corresponding spherical bearing.

[0008] Preferably, a reinforcing rib is provided on the loading plate, the reinforcing rib is located directly below the wheel axle, and its extension direction is perpendicular to the wheel axle axis.

[0009] Preferably, the main strut dummy and the upper support arm dummy are both mounted on the main pivot dummy. The other end of the main strut dummy is connected to one end of the lower rocker arm dummy, the other end of the upper support arm dummy is connected to one end of the buffer dummy, and the other end of the buffer dummy is connected to the lower rocker arm dummy. One end of the retraction actuator dummy is connected to the main strut dummy, and the other end is connected to the corresponding aircraft connector. One end of the small strut dummy is connected to the upper support arm dummy, and the other end is connected to the corresponding aircraft connector. The main pivot dummy mounts the rocker arm landing gear dummy onto the corresponding aircraft connector.

[0010] Preferably, one end of the main support dummy is provided with a main support rotating sleeve that cooperates with the main rotating shaft dummy, and the main support rotating sleeve is fitted onto the main rotating shaft dummy. The other end is provided with a lower rocker arm connecting double lug that connects to the lower rocker arm dummy. A retraction and extension actuator lower connector connecting double lug is provided on the column body of the main support dummy that connects to the retraction and extension actuator dummy.

[0011] Preferably, the angle between the axis of the main support rotating sleeve and the axis of the main support dummy support is the same as the angle between the main support and the main rotating shaft.

[0012] Preferably, one end of the upper support arm dummy is provided with an upper support arm rotating sleeve that cooperates with the main rotating shaft dummy, and the other end is provided with a buffer upper connecting double lug that connects to the buffer dummy; a plurality of upper support arm positioning pin holes are opened radially along the upper support arm rotating sleeve, and the upper support arm positioning pin holes correspond to the main rotating shaft positioning pin holes opened on the main rotating shaft dummy.

[0013] Preferably, the retraction actuator dummy includes a retraction actuator straight rod, an upper connecting lug of the retraction actuator, and a lower connecting lug of the retraction actuator. The upper and lower connecting lugs of the retraction actuator are located at both ends of the retraction actuator straight rod and are screwed to it. Corresponding spherical bearings are installed inside the upper and lower connecting lugs of the retraction actuator. The retraction actuator dummy is connected to the corresponding connectors and main strut dummy of the aircraft through the upper and lower connecting lugs of the retraction actuator.

[0014] Preferably, the small strut dummy includes a small strut straight rod, a single upper connecting lug on the small strut, and a double lower connecting lug on the small strut. The single upper connecting lug and the double lower connecting lug are respectively located at both ends of the small strut straight rod and are connected by positive and negative threads. A corresponding spherical bearing is installed inside the single upper connecting lug on the small strut and connected to the corresponding connector on the aircraft. The double lower connecting lug on the small strut is connected to the upper arm dummy.

[0015] Preferably, the buffer dummy adopts an integral rod design with two mutually perpendicular single lugs at both ends; and corresponding joint bearings are installed in the single lugs; the single lugs at both ends are respectively connected to the upper support arm dummy and the lower rocker arm dummy.

[0016] Compared with the prior art, the present invention has the following advantages: 1. It can transfer the ground load of the landing gear to the corresponding structure of the aircraft, and assess the fatigue strength and life of the aircraft structure; 2. Select appropriate materials to make their strength higher than that of the actual landing gear, so as to meet the full cycle of fatigue testing of the entire aircraft; 3. Using this device to replace the actual landing gear is less expensive than using the actual landing gear, and can save the cost of full-aircraft fatigue testing; 4. Based on the ground spectrum requirements of the full-aircraft fatigue test, determine the compression stroke of the buffer and design the length S of the buffer dummy component to the required value to achieve the functional requirements of the rocker arm landing gear. 5. It is designed with a fixed support frame, which can be used to support the aircraft when it is static. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the force transmission node according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the main support dummy structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the lower rocker arm dummy structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of the upper support arm dummy structure in an embodiment of the present invention; Figure 6 This is a schematic diagram of the main shaft dummy component in an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of the retractable actuator cylinder dummy in an embodiment of the present invention; Figure 8 This is a schematic diagram of the small strut dummy structure in an embodiment of the present invention; Figure 9 This is a schematic diagram of the buffer dummy structure in an embodiment of the present invention; Figure 10 This is a schematic diagram of the dummy wheel structure in an embodiment of the present invention; Figure 11 This is a schematic diagram of the connecting bolt structure on the buffer in an embodiment of the present invention.

[0018] Figure 1 In the middle: 1-Main support dummy; 2-Lower rocker arm dummy; 3-Upper support arm dummy; 4-Main shaft dummy; 5-Retraction / extension actuator dummy; 6-Small support rod dummy; 7-Damper dummy; 8-Dummy wheel; 9-Jack fixing bracket; 10-Main shaft fixing nut; 11-Upper support arm fixing pin; 12-Damper upper connecting bolt; 13-Damper lower connecting bolt; 14-Lower rocker arm fixing bolt; 15-Retraction / extension actuator lower connecting bolt; 16-Retraction / extension actuator upper connecting bolt; 17-Small support rod lower connecting bolt; 18-Small support rod upper connecting bolt; 19-Dummy wheel positioning pin; Figure 2 In the diagram, A - front mounting point of the main shaft; B - rear mounting point of the main shaft; C - upper fixing point of the buffer; D - lower fixing point of the buffer; E - lower rocker arm rotation point; F - wheel axle fixing point; G - lower fixing point of the retraction actuator; H - upper fixing point of the retraction actuator; M - lower fixing point of the small support rod; N - upper fixing point of the small support rod; L - wheel axle distance; S - length of the buffer dummy component; θ - angle between the main support and the main shaft. Figure 3 In the middle, 20-main support rotating sleeve; 21-lower connector of retraction actuator cylinder connecting double lugs; 22-lower rocker arm connecting double lugs; Figure 4 In the middle, 23-main support connecting single lug; 24-buffer connecting double lug; 25-dummy wheel anti-rotation mounting hole; Figure 5 In the middle, 26-upper arm rotating sleeve; 27-double lugs connecting the buffer; 28-positioning pin hole of the upper arm; Figure 6 In the middle, 29 - main shaft positioning pin hole; Figure 7 In the middle, 30-straight rod of the retraction / expansion actuator; 31-upper connecting lug of the retraction / expansion actuator; 32-lower connecting lug of the retraction / expansion actuator; Figure 8 In the middle, 33-small support rod is a straight rod; 34-single lug is connected to the upper part of the small support rod; 35-double lug is connected to the lower part of the small support rod. Figure 9 In the middle, 36-spherical plain bearing; Figure 10 In the middle section, 37-wheel axle anti-rotation mating section; 38-wheel axle; 39-loading plate; 40-reinforcing rib; 41-wheel center X-direction loading hole; 42-wheel center Y-direction loading hole; 43-contact point loading hole; Figure 11 In the middle, the lower connector of the 44-small strut is connected to a single lug. Implementation

[0019] The following is in conjunction with the appendix Figures 1-11 Further explanation of the rocker arm landing gear dummy: In the full-aircraft fatigue test of a certain type of trainer aircraft, a landing gear dummy was designed to apply ground-spectrum loads to the landing gear, so that the loads in all directions were transferred to the aircraft structure in a real manner, and the fatigue strength and life of the aircraft structure were assessed.

[0020] Based on the structure of a real rocker arm landing gear, the force transmission path, coordinates, and constraint forms of the joint nodes are determined. A corresponding dummy mechanism is then designed, such as a rocker arm landing gear dummy mechanism. Figure 1 As shown, it includes main support dummy 1, lower rocker arm dummy 2, upper support arm dummy 3, main shaft dummy 4, buffer dummy 5, retraction actuator dummy 6, small support rod dummy 7, dummy wheel 8 and jack fixing bracket 9. Install the main support dummy 1 and the upper support arm dummy 3 onto the main pivot dummy 4. Fix the upper support arm dummy 3 and the main pivot dummy 4 together with the upper support arm fixing pin 11. Determine the installation position of the main pivot dummy 4 according to the coordinates of the front mounting point A and the rear mounting point B of the main pivot. The lower rocker arm dummy 2 is connected to the main support dummy 1 via the lower rocker arm fixing bolt 14. The dummy wheel 8 is installed in the dummy wheel anti-rotation mounting hole 25 of the lower rocker arm dummy 2 via the wheel axle anti-rotation fitting section 37, and the dummy wheel positioning pin 19 is installed to fix the dummy wheel 8. The buffer dummy 7 is connected to the upper support arm dummy 3 and the lower rocker arm dummy 2 respectively via the upper connecting bolt 12 and the lower connecting bolt 13 of the buffer; The retraction actuator dummy 5 is connected to the retraction actuator lower connector connecting double lug 21 of the main strut dummy 1 via the retraction actuator lower connecting bolt 15, and is connected to the corresponding connector of the aircraft via the retraction actuator upper connecting bolt 16. The small strut dummy 6 is connected to the small strut lower connector connecting lug 44 of the buffer upper connecting bolt 12 via the small strut lower connecting bolt 17, and connected to the corresponding connector of the aircraft via the small strut upper connecting bolt 18. The installation position of the aircraft structure is matched by adjusting the positive and negative threads of the small strut dummy 6.

[0021] The above installation forms the ground assembly of the entire rocker arm landing gear dummy. The rocker arm landing gear dummy is installed on the corresponding joint of the aircraft through the main shaft dummy 4, realizing the on-board installation of the rocker arm landing gear dummy. By applying the corresponding ground load in the dummy wheel 8, the aircraft is tested.

[0022] When the aircraft is in a static state, it is connected to the ground equipment via the jack fixing bracket 9 in the rocker arm landing gear dummy to keep the aircraft in a stable state.

[0023] Specifically, In this device, to ensure the authenticity of force transmission, it is essential to ensure that the coordinates and constraint methods of the key force transmission points of the dummy are consistent with those of the actual landing gear. For example... Figure 2 As shown, the front mounting point A and rear mounting point B of the main shaft are the coordinate points connecting the device of this invention to the aircraft connector. The upper fixed point C and lower fixed point D of the buffer are used to ensure the force transmission path of the buffer dummy. The lower rocker arm rotation point E and wheel axle fixed point F are used to ensure the force transmission path of the lower rocker arm dummy. The angle θ between the lower rocker arm rotation point E, the main support, and the main shaft is used to ensure the force transmission path of the main support dummy. The lower fixed point G and upper fixed point H of the retraction actuator are used to ensure the force transmission path of the retraction actuator dummy. The lower fixed point M and upper fixed point N of the small support rod are used to ensure the force transmission path of the small support rod dummy. The wheel axle distance L is used to ensure the realism of the effect of the landing gear loads in all directions on the fuselage. The length S of the buffer dummy is used to simulate the total length of the landing gear buffer under a certain compression stroke.

[0024] like Figure 3 As shown, the main support dummy 1 is designed with a main support rotating sleeve 20 that cooperates with the main rotating shaft dummy 4, a lower connector connecting double lugs 21 for the retracting and extending actuator cylinder dummy 5, and a lower rocker arm connecting double lugs 22 for the lower rocker arm dummy 2. The angle between the axis of the main support rotating sleeve 20 and the axis of the main support dummy 1 is consistent with the angle θ between the main support and the main rotating shaft. The center point of the lower connector connecting double lugs 21 for the retracting and extending actuator cylinder is consistent with the coordinate of the lower fixed point G of the retracting and extending actuator cylinder. The center point of the lower rocker arm connecting double lugs 22 is consistent with the coordinate of the lower rocker arm rotation point E.

[0025] like Figure 4 As shown, the lower rocker arm dummy 2 is designed with a main support connecting single lug 23 connected to the main support dummy 1, a buffer lower connecting double lug 24 connected to the buffer dummy 7, and a dummy wheel anti-rotation mounting hole 25 connected to the dummy wheel 8. The center point of the main support connecting single lug 23 is consistent with the coordinate of the lower rocker arm rotation point E. The center point of the buffer upper connecting double lug 24 is consistent with the coordinate of the buffer lower fixing point D. The center point of the dummy wheel anti-rotation mounting hole 25 is consistent with the coordinate of the wheel axle fixing point F.

[0026] like Figure 5 As shown, the upper support arm dummy 3 is designed with an upper support arm rotating sleeve 26 that cooperates with the main rotating shaft dummy 4, a buffer upper connecting double lug 27 that connects to the buffer dummy 7, and an upper support arm positioning pin hole 28 that connects to the main rotating shaft dummy 4. The center point of the buffer upper connecting double lug 27 is consistent with the coordinate of the fixed point C on the buffer.

[0027] like Figure 6 As shown, the main shaft dummy 4 is designed with a main shaft positioning pin hole 29 that connects to the upper support arm dummy 3.

[0028] like Figure 7As shown, the retractable actuator dummy 5 includes a retractable actuator straight rod 30, an upper connecting lug 31, and a lower connecting lug 32. Corresponding spherical bearings are fitted into the upper connecting lug 31 and the lower connecting lug 32. The upper connecting lug 31 and the lower connecting lug 32 are threadedly connected to the retractable actuator straight rod 30. The center of the spherical bearing in the upper connecting lug 31 coincides with the coordinate of the fixed point H on the upper retractable actuator, and the center of the spherical bearing in the lower connecting lug 32 coincides with the coordinate of the fixed point G on the lower retractable actuator.

[0029] like Figure 8 As shown, the small support dummy 6 is designed with a small support straight tube 33, a single upper connecting lug 34, and a double lower connecting lug 35. A corresponding spherical bearing is fitted into the single upper connecting lug 34. The single upper connecting lug 34 and the double lower connecting lug 35 are connected to the small support straight tube 33 by positive and negative threads, respectively, allowing for flexible adjustment of the effective length of the small support dummy 6. The center of the spherical bearing in the single upper connecting lug 34 is aligned with the coordinate of the fixed point N on the small support; as shown... Figure 11 As shown, the double lugs 35 connected to the small support rod are connected to the single lug 44 of the small support rod connector connected to the bolt 12 on the buffer, and the coordinates are consistent with the fixed point M of the small support rod.

[0030] like Figure 9 As shown, the dummy buffer 7 adopts an integral rod design with two ends designed as mutually perpendicular single lugs, and a corresponding spherical bearing 36 is installed in the single lug, so that the distance between the center points of the spherical bearings is consistent with the length S of the dummy buffer. The specific value of the length S of the dummy buffer is determined according to the actual landing gear buffer compression stroke requirements.

[0031] like Figure 10 As shown, the dummy wheel 8 is designed with a wheel axle 38, a loading plate 39, and a reinforcing rib 40. At one end of the wheel axle 38, there is a wheel axle anti-rotation fitting section 37 that connects and cooperates with the lower rocker arm dummy 2. The wheel axle anti-rotation fitting section 37 is designed as a square to transmit the X-direction load of the landing gear contact point. The loading plate 39 is designed with a wheel center X-direction loading hole 41, a wheel center Y-direction loading hole 42, and a contact point loading hole 43, and corresponding spherical bearings are installed in the holes.

[0032] like Figure 1 As shown, a jack fixing bracket 9 is designed at the end of the lower rocker arm dummy 2, and the jack fixing bracket 9 is connected to the lower rocker arm dummy 2 by welding.

[0033] The aforementioned devices are connected by corresponding connecting bolts to form the device, ensuring the coordinates and constraint forms of each key node, simulating the force transmission path of the real landing gear, applying corresponding loads through the loading holes in each direction in the loading plate 39, assessing the fatigue strength and life of the aircraft structure, and connecting to ground equipment through the jack fixing bracket 9 in a static state to play a role in stabilizing and supporting the aircraft.

Claims

1. A rocker arm type landing gear dummy, whose key force transmission point coordinates and constraint methods are consistent with those of a real landing gear, and whose structural strength meets the requirements of the entire fatigue test cycle of the whole aircraft, includes a main strut dummy, a lower rocker arm dummy, an upper support arm dummy, a main shaft dummy, a buffer dummy, a retraction and extension actuator dummy, and a small strut dummy, characterized in that: It also includes a dummy wheel and a fixed bracket; the dummy wheel includes an axle and a loading plate. One end of the axle is a polygonal anti-rotation mating section for transmitting the X-direction load of the landing gear contact point. The anti-rotation mating section is adapted to and inserted into the mounting holes on the lower rocker arm dummy. The loading plate is located at the other end of the axle and has several loading holes for connecting loading equipment. The fixed bracket is installed at the end of the lower rocker arm dummy for supporting the aircraft when it is static. The main strut dummy and the upper control arm dummy are both mounted on the main pivot dummy. The other end of the main strut dummy is connected to one end of the lower rocker arm dummy, the other end of the upper control arm dummy is connected to one end of the buffer dummy, and the other end of the buffer dummy is connected to the lower rocker arm dummy. One end of the retraction actuator dummy is connected to the main strut dummy, and the other end is connected to the corresponding aircraft connector. One end of the small strut dummy is connected to the upper control arm dummy, and the other end is connected to the corresponding aircraft connector. The main pivot dummy mounts the rocker arm landing gear dummy onto the corresponding aircraft connector. One end of the upper support arm dummy is provided with an upper support arm rotating sleeve that mates with the main rotating shaft dummy, and the other end is provided with a buffer upper connecting double lugs that connect with the buffer dummy; a number of upper support arm positioning pin holes are opened radially along the upper support arm rotating sleeve, and the upper support arm positioning pin holes correspond to the main rotating shaft positioning pin holes opened on the main rotating shaft dummy.

2. The rocker arm type landing gear dummy according to claim 1, characterized in that: The loading holes include the wheel center X-axis loading hole, the wheel center Y-axis loading hole, and the contact point loading hole; each loading hole is fitted with a corresponding spherical bearing.

3. The rocker arm type landing gear dummy according to claim 1, characterized in that: A reinforcing rib is provided on the loading plate. The reinforcing rib is located directly below the wheel axle, and its extension direction is perpendicular to the wheel axle axis.

4. The rocker arm type landing gear dummy according to claim 1, characterized in that: One end of the main support dummy is provided with a main support rotating sleeve that cooperates with the main rotating shaft dummy. The main support rotating sleeve is fitted onto the main rotating shaft dummy. The other end is provided with a lower rocker arm connecting double lug that connects to the lower rocker arm dummy. On the column of the main support dummy, there is a retraction and extension actuator lower connector connecting double lug that connects to the retraction and extension actuator dummy.

5. The rocker arm type landing gear dummy according to claim 4, characterized in that: The angle between the axis of the main support rotating sleeve and the axis of the main support dummy support is the same as the angle between the main support and the main rotating shaft.

6. The rocker arm type landing gear dummy according to claim 1, characterized in that: The retraction actuator dummy includes a retraction actuator straight rod, an upper connecting lug of the retraction actuator, and a lower connecting lug of the retraction actuator. The upper and lower connecting lugs of the retraction actuator are located at both ends of the retraction actuator straight rod and are screwed to it. Corresponding spherical bearings are installed inside the upper and lower connecting lugs of the retraction actuator. The retraction actuator dummy is connected to the corresponding connectors and main strut dummy of the aircraft through the upper and lower connecting lugs of the retraction actuator.

7. The rocker arm type landing gear dummy according to claim 1, characterized in that: The small strut dummy includes a small strut straight rod, a single upper connecting lug, and a double lower connecting lug. The single upper connecting lug and the double lower connecting lug are respectively located at both ends of the small strut straight rod and are connected by positive and negative threads. A corresponding spherical bearing is installed inside the single upper connecting lug and connects to the corresponding connector on the aircraft. The double lower connecting lug connects to the upper boom dummy.

8. The rocker arm type landing gear dummy according to claim 1, characterized in that: The buffer dummy adopts an integral rod design with two mutually perpendicular single lugs at both ends; and corresponding spherical bearings are installed in the single lugs; Its two ends are connected to the upper support arm dummy and the lower rocker arm dummy, respectively.

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