Wing spar spacing adjusting device for morphing wing

Abstract

The invention discloses a spar spacing adjusting device for a morphing wing, and belongs to the field of morphing aircraft structural design, the device comprises a fuselage force bearing framework, a sliding rail is arranged on the fuselage force bearing framework, and a fixed connecting support is fixed on the fuselage force bearing framework; the sliding connection support is matched with a sliding rail on a fuselage bearing framework and can slide in parallel along the axis of a fuselage. Connecting plates used for installing spars are welded to the side faces, back on to the fuselage force bearing framework, of the fixed connecting supports and the sliding connecting supports; the fixed wing spar and the movable wing spar are fixedly connected with the fixed connecting support and the sliding connecting support through connecting plates respectively; the lead screw nut is connected with the sliding connection support, the stepping motor drives the lead screw to rotate, the lead screw nut drives the sliding connection support to slide along the axis of the fuselage, and the distance between the fixed wing spar and the movable wing spar is adjusted. The chord length of the wing is changed by changing the chordwise distance between the spars by sliding the sliding connection supports along the axis direction of the fuselage. A sliding connection support is arranged on a force bearing framework of a fuselage, a movable wing spar is fixed to the sliding connection support, a motor is used for driving the movable wing spar to slide along the axis of the fuselage, and the chord length and the area of a wing are changed.

Description

Technical Field

[0001] The present invention belongs to the field of variant aircraft structure design, and in particular relates to a wing spar spacing adjustment device, which can be applied to the wings of the variant aircraft to drive and control the wings to change the wing area. Background Art

[0002] During flight, morphing aircraft can adjust wing geometry—such as chord length, span, wing area, camber, and thickness—according to the flight environment to improve aerodynamic characteristics and enhance flight performance. Changing the wing chord length not only alters the aspect ratio but also changes the aerodynamic area, thereby increasing lift, improving the lift-to-drag ratio, and optimizing flight performance. Therefore, changing the wing chord length is crucial for morphing aircraft. During this chord change, the wing spar experiences significant bending moments. This bending moment must be balanced within the fuselage, making the connection between the wing spar and the fuselage crucial for adjusting spar spacing.

[0003] Among the currently public research on variant aircraft, there are only some principle studies, and practical wing chord length devices are still rare. Summary of the Invention

[0004] To address the issue of variable wing chord length, the present invention discloses a spar spacing adjustment device for a variable-length wing. This device uses a sliding connection support that slides along the fuselage axis, changing the chord-wise distance between the spars to achieve variable wing chord length. The sliding connection support is mounted on the fuselage's load-bearing frame, and the movable wing spars are fixed to the sliding connection support. A motor drives the movable wing spars to slide along the fuselage axis, changing the chord length and area of the wing.

[0005] To achieve the above object, the present invention provides the following solutions: The device described in the present invention includes a fuselage load-bearing frame, a fixed connecting support, a sliding connecting support, a connecting plate, a fixed wing spar, a movable wing spar, a stepping motor, a lead screw, a lead screw nut, and an auxiliary drive rod. The stepping motor drives the lead screw to rotate, causing the lead screw nut to drive the sliding connecting support to translate along the fuselage load-bearing frame. The sliding connecting support, connected to the movable wing spar through a connecting plate, drives the movable wing spar to translate along the fuselage load-bearing frame, thereby changing the wing chord length. Specifically: a sliding track is provided on the fuselage load-bearing frame, and the fixed connecting support is fixed on the fuselage load-bearing frame; the sliding connecting support is adapted to the sliding track on the fuselage load-bearing frame and can slide parallel to the fuselage axis; a connecting plate for installing the wing beam is welded on the side of the fixed connecting support and the sliding connecting support facing away from the fuselage load-bearing frame; the wing beam includes a fixed wing beam and a movable wing beam, and the fixed wing beam and the movable wing beam are respectively fixed to the fixed connecting support and the sliding connecting support through the connecting plate; the screw nut is connected to the sliding connecting support, and the stepper motor drives the screw to rotate, and the screw nut drives the sliding connecting support to slide along the fuselage axis to adjust the distance between the fixed wing beam and the movable wing beam; the auxiliary drive rod is set at an appropriate position away from the fuselage axis direction, and the driving stroke is consistent with the screw drive stroke, overcoming the in-plane tension of the flexible skin and keeping the fixed wing beam and the movable wing beam parallel.

[0006] Furthermore, the fuselage load-bearing frame adopts a closed square cross-section, which can ensure the longitudinal bending stiffness and torsional stiffness of the fuselage load-bearing frame, and can withstand a larger wing root bending moment; the cross-section of the fixed wing spar and the movable wing spar is I-shaped, and one end of the wing spar is connected to the connecting plate on the corresponding fixed connecting support and the sliding connecting support.

[0007] Furthermore, the fixed wing beam is connected to the front beam position corresponding to the fuselage load-bearing frame through a fixed connecting support; the movable wing beam is connected to the rear beam position corresponding to the fuselage load-bearing frame through a sliding connecting support; the sliding connecting support can slide on the fuselage load-bearing frame in a nested manner, or be connected to the sliding rails on both sides of the fuselage load-bearing frame in a sliding groove manner; the outer surface of the nested sliding part on the fuselage load-bearing frame is as smooth as possible to reduce friction resistance and ensure sufficient sliding stroke.

[0008] Furthermore, the fixed connection support adopts a closed square cross-section tube, which is nested and connected with the closed square cross-section of the fuselage load-bearing frame. The length along the fuselage axis is equivalent to the width of the edge strip of the fixed wing beam. The fixed connection support is connected to the fuselage load-bearing frame by bolts.

[0009] Furthermore, the sliding connection support adopts a closed square cross-section tube, which is nested and connected with the closed square cross-section of the fuselage load-bearing frame. The length along the fuselage axis is equivalent to the width of the edge strip of the movable wing beam; the inner surface of the sliding connection support slides relative to the outer surface of the fuselage load-bearing frame to ensure that its surface is as smooth as possible and reduce friction resistance.

[0010] Furthermore, the lead screw nut is connected to the upper side of the sliding connection support via a bolt, the stepper motor drives the lead screw to rotate, and the lead screw nut drives the sliding connection support to slide along the axis of the fuselage. The sliding connection support, lead screw, lead screw nut, and stepper motor constitute a drive system.

[0011] Furthermore, the connecting plate has a C-shaped cross-section, with the upper and lower edges of the connecting plate connected to the flanges of the fixed spar and the movable spar, and the side surfaces of the connecting plate welded to the side surfaces of the fixed connecting support and the sliding connecting support. The upper and lower edges of the connecting plate's C-shaped cross-section are long enough to accommodate at least two rows of bolt holes, and the height is sufficient to accommodate the height of the spar. The length of the connecting plate along the fuselage axis is consistent with the length of the sliding connecting support along the fuselage axis. The two connecting supports have the same axial length.

[0012] Furthermore, the screw is arranged on the fuselage load-bearing frame, the screw axis is parallel to the fuselage axis, and the length meets the sliding stroke and installation space requirements of the sliding connection support; the internal thread of the screw nut is adapted to the thread of the screw, and there is a boss on the external screw nut, the height and width of the boss are the same as the depth and width of the groove; the screw nut is fixed to the inner side of the sliding connection support through the boss; the model of the stepper motor is selected, and the driving force of the stepper motor along the fuselage axis direction is sufficient to overcome the resistance in the process of adjusting the wing beam spacing.

[0013] Furthermore, the screw is arranged inside the fuselage load-bearing frame (near the fuselage axis position), and a corresponding slot along the fuselage axis direction is opened on the fuselage load-bearing frame corresponding to the position where the screw nut is connected to the sliding connection support. The length of the slot meets the wing beam spacing adjustment range requirements.

[0014] The beneficial effects of the present invention compared with the prior art are: This invention proposes a specific solution for changing the wing chord length: a stepper motor drives the leadscrew, which in turn drives the sliding connection support to translate along the fuselage load-bearing frame. The sliding connection support, connected to the movable spar via a connecting plate, propels the movable spar to translate along the fuselage load-bearing frame, thereby flexibly adjusting the wing chord length as needed. This not only translates the variable chord length design from theory to a practical device, but also ensures the device's safety and reliability, effectively improving the performance of the variable-length aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an assembly diagram of the spar spacing adjustment device for a variant wing according to the present invention; Figure 2 A schematic diagram of the fuselage load-bearing skeleton structure of the present invention; Figure 3 This is a simplified structural diagram of the screw nut of the present invention; Figure 4This is a cross-sectional view of the assembly of the sliding connection support and the lead screw of the present invention; Figure 5 This is a cross-sectional view of the assembly of the connecting plate and the spar of the present invention; Among them, 1-fuselage load-bearing frame, 2-fixed wing beam, 3-movable wing beam, 4-fixed connecting support; 5-sliding connecting support, 6-connecting plate, 7-screw, 8-screw nut, 9-stepping motor, 10-drive system, 11-auxiliary drive rod, 12-groove, 13-boss. DETAILED DESCRIPTION

[0016] In order to describe the purpose, effect and technical solution of the present invention in detail, an example is given below to further illustrate the present invention. It should be noted that the example given here is only used to explain the present invention and is not used to limit the present invention.

[0017] like Figure 1 As shown, a wing beam spacing adjustment device for a variant wing of the present invention includes a fuselage load-bearing frame 1, a fixed connecting support 4, a sliding connecting support 5, a connecting plate 6, a fixed wing beam 2, a movable wing beam 3, a stepper motor 9, a screw 7, a screw nut 8, and an auxiliary drive rod 11.

[0018] like Figures 4 and 5 As shown, a sliding track is provided on the fuselage load-bearing frame 1, and a fixed connection support 4 is fixed to the fuselage load-bearing frame 1; a sliding connection support 5 is adapted to the sliding track on the fuselage load-bearing frame 1 and can slide parallel to the fuselage axis; a connecting plate 6 for mounting the wing beam is welded to the side of the fixed connection support 4 and the sliding connection support 5 facing away from the fuselage load-bearing frame; the fixed wing beam 2 and the movable wing beam 3 are respectively fixed to the fixed connection support 4 and the sliding connection support 5 via the connecting plate; a screw nut 8 is connected to the sliding connection support 5, and a stepper motor 9 drives the screw 7 to rotate, which drives the sliding connection support 5 to slide along the fuselage axis to adjust the distance between the fixed wing beam 2 and the movable wing beam 3. The sliding connection support 5, screw 7, screw nut 8, and stepper motor 9 constitute a drive system 10.

[0019] The auxiliary drive rod 11 is set at an appropriate position away from the fuselage axis direction. The drive stroke is consistent with the screw drive stroke, overcoming the in-plane tension of the flexible skin and keeping the fixed wing beam 2 and the movable wing beam 3 parallel.

[0020] The following is a detailed description of the wing spar spacing adjustment device for a variant wing according to the present invention. Suppose you have a drone and need to change the chord length of its wings. Select a section of the fuselage and the left wing. The span is 1200mm, the initial spacing between the front and rear beams is 600mm, and the chord length can be changed from 0 to 225mm. The specific components are as follows: The fuselage load-bearing frame 1 is an aluminum alloy square cross-section tube with a length of 1000mm, an outer side length of 100mm, and a wall thickness of 5mm. The outer side of the fuselage load-bearing frame 1 is polished within the range of motion of the sliding connection support 5. A rectangular groove 12 is opened along the symmetry axis at a distance of 100~400mm from the tail end of the load-bearing frame, and the first end of the groove 12 is 400mm away from the tail end of the fuselage load-bearing frame 1. The rectangular groove 12 is 300mm long, 20mm wide, and 5mm deep. The structure of the fuselage load-bearing frame 1 is as follows Figure 2 shown.

[0021] The fixed spar 2 is an aluminum alloy I-beam with a cross-sectional height of 190 mm, a span length of 1200 mm, a flange width of 75 mm, and a web and flange thickness of 4 mm.

[0022] The material selection, size and installation method of the movable spar 3 are the same as those of the front spar.

[0023] The fixed connection bracket 4 is an aluminum alloy square-section tube. Its length along the axis of the fuselage support frame 1 (hereinafter referred to as the "axial direction") is 75 mm, its inner cross-section is 100 mm long, and its wall thickness is 5 mm. The inner cross-sectional dimensions of the fixed connection bracket 4 match the outer cross-sectional dimensions of the fuselage support frame 1 and are fixed to the outer side of the fuselage support frame 1 with screws.

[0024] The sliding connection support 5 is an aluminum alloy square cross-section tube with an axial length of 75mm, an inner cross-section side length of 100mm, and a wall thickness of 5mm. The inner cross-sectional dimensions of the sliding connection support 5 match the outer cross-sectional dimensions of the fuselage load-bearing frame 1. It is nested outside the fuselage load-bearing frame 1 and slides axially.

[0025] Connecting plate 6 is made from hot-rolled channel steel. The channel has a cross-sectional height of 200mm, a leg width of 70mm, and an axial length of 75mm. After machining the inner surface of the channel, connecting plate 6 forms a U-shaped channel structure. Its inner side is 190mm high and its wall thickness is 5mm. The inner side of connecting plate 6 connects to the upper and lower flanges of the spar, allowing for spar mounting.

[0026] The cross section of the lead screw nut 8 is a convex alloy part with a structure as follows: Figure 3 As shown. The cross-section of the rectangular base is 70mm high, 80mm wide, and 40mm thick in the axial direction. There is a boss 13 at a symmetrical position on the upper side of the rectangular base. The boss 13 is 10mm high, 20mm wide, and 40mm thick in the axial direction. The threaded hole that cooperates with the screw 7 is located in the center of the rectangular base, penetrates the base in depth, has an outer diameter of 20mm, and the center of the hole is 50mm away from the lower bottom surface of the inner side of the fuselage load-bearing frame 1. The boss 13 passes through the groove 12 above the fuselage load-bearing frame 1, and the top is connected to the inner side of the sliding connection support 5, so that the sliding connection support 5 can follow the screw nut 8 to make reciprocating motion in the horizontal direction.

[0027] The lead screw 7 is a ball screw 7. It is 600 mm long, 20 mm in diameter, and has an output thrust of 250 N. The lead screw 7 is fixed to the interior of the fuselage load-bearing frame 1 via a mounting platform and engages with the lead screw nut 8. The center axis of the lead screw 7 is 50 mm from the inner lower surface of the fuselage load-bearing frame 1.

[0028] The motor is a stepper motor 9 matched with the lead screw 7.

[0029] The auxiliary driving rod 11 is located between the fixed wing spar 2 and the movable wing spar 3, and adjusts the movable wing spar 3 to produce a stable displacement along the fuselage load-bearing frame 1.

[0030] By assembling the above components, the device can change the chord length.

[0031] In the described scenario, the motor drives the lead screw 7 to rotate, causing the lead screw nut 8 to drive the sliding connection support 5 to move horizontally along the fuselage load-bearing frame 1; the sliding connection support 5 is connected to the movable wing spar 3 through the connecting plate, pushing the movable wing spar 3 to move horizontally along the fuselage load-bearing frame 1. Controlling the start and stop of the motor can drive the drone's movable wing spar 3 to produce a specified amount of displacement along the chord direction, with a displacement range of 0 to 225mm. When the sliding connection support 5 is docked at the head end of the groove 12, the distance between the front and rear beams is 600mm, that is, the distance between the front and rear beams can be adjusted within a range of 600 to 825mm.

[0032] The above description is merely one application of the present invention. It should be noted that, without departing from the principles of the present invention, appropriate improvements to the materials, structural dimensions, or motor power of various components to ensure structural safety and reliability, and to achieve ideal torsional deformation of the wing after overcoming all obstructive torques, are also considered within the scope of protection of the present invention.

Claims

1. A spar spacing adjustment device for a morphing wing, characterized in that: The device comprises a fuselage load-bearing frame (1), a sliding track is provided on the fuselage load-bearing frame (1), and a fixed connection support (4) is fixed on the fuselage load-bearing frame (1); the sliding connection support (5) is adapted to the sliding track on the fuselage load-bearing frame (1) and can slide parallel to the fuselage axis; A connecting plate (6) for mounting a wing spar is welded on the side of the fixed connecting support (4) and the sliding connecting support (5) facing away from the fuselage load-bearing frame; the wing spar includes a fixed wing spar (2) and a movable wing spar (3), and the fixed wing spar (2) and the movable wing spar (3) are respectively fixedly connected to the fixed connecting support (4) and the sliding connecting support (5) via the connecting plate (6); The lead screw nut (8) is connected to the sliding connection support (5), the stepping motor (9) drives the lead screw (7) to rotate, and the lead screw nut (8) drives the sliding connection support (5) to slide along the fuselage axis to adjust the distance between the fixed wing beam (2) and the movable wing beam (3); The auxiliary driving rod (11) is set at an appropriate position away from the fuselage axis direction, and the driving stroke is consistent with the driving stroke of the screw (7), overcoming the in-plane tension of the flexible skin and keeping the fixed wing beam (2) and the movable wing beam (3) parallel.

2. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The fuselage load-bearing frame (1) adopts a closed square cross-section, which can ensure the longitudinal bending stiffness and torsional stiffness of the fuselage load-bearing frame (1) and can withstand a large wing root bending moment; the cross-sections of the fixed wing beam (2) and the movable wing beam (3) are I-shaped, and one end of the wing beam is connected to the connecting plate on the corresponding fixed connection support and the sliding connection support.

3. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The fixed wing beam (2) is connected to the front beam position corresponding to the fuselage load-bearing frame (1) through a fixed connecting support (4); the movable wing beam (3) is connected to the rear beam position corresponding to the fuselage load-bearing frame (1) through a sliding connecting support (5); the sliding connecting support (5) can slide on the fuselage load-bearing frame (1) in a nested manner, or be connected to the slide rails on both sides of the fuselage load-bearing frame (1) in a sliding groove manner; the outer surface of the nested sliding part on the fuselage load-bearing frame (1) is as smooth as possible to reduce friction resistance and ensure sufficient sliding stroke.

4. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The fixed connection support (4) is a closed square cross-section tube, which is nested and connected with the closed square cross-section of the fuselage load-bearing frame (1). The length along the fuselage axis is equivalent to the width of the edge of the fixed wing beam (2). The fixed connection support (4) is connected to the fuselage load-bearing frame (1) by bolts.

5. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The sliding connection support (5) is a closed square cross-section tube, which is nested and connected with the closed square cross-section of the fuselage load-bearing frame (1), and its length along the fuselage axis is equivalent to the width of the edge strip of the movable wing beam (3); the inner surface of the sliding connection support slides relative to the outer surface of the fuselage load-bearing frame (1), ensuring that the surface is as smooth as possible and reducing friction resistance.

6. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The lead screw nut (8) is connected to the upper side of the sliding connection support (5) through a bolt, the stepping motor (9) drives the lead screw (7) to rotate, and the lead screw nut (8) drives the sliding connection support (5) to slide along the axis of the fuselage; the sliding connection support (5), the lead screw (7), the lead screw nut (8), and the stepping motor (9) constitute a driving system (10).

7. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The cross-sectional shape of the connecting plate (6) is C-shaped. The upper and lower sides of the connecting plate (6) are connected to the edges of the fixed wing beam (2) and the movable wing beam (3). The side of the connecting plate (6) is welded to the side of the fixed connection support and the sliding connection support. The length of the upper and lower sides of the C-shaped cross-sectional shape of the connecting plate (6) must ensure that at least two rows of bolt holes can be set. The height must be able to accommodate the height of the wing beam. The length of the connecting plate (6) along the fuselage axis is consistent with the length of the sliding connection support (5) along the fuselage axis.

8. The spar spacing adjustment device for a morphing wing according to claim 1, characterized in that: The lead screw (7) is arranged on the fuselage load-bearing frame (1), the lead screw axis is parallel to the fuselage axis, and the length meets the sliding stroke and installation space requirements of the sliding connection support (5); the internal thread of the lead screw nut (8) is adapted to the thread of the lead screw (7), and a boss (13) is provided on the external lead screw nut (8), and the height and width of the boss (13) are the same as the depth and width of the groove (12); the lead screw nut (8) is fixed to the inner side of the sliding connection support (5) through the boss (13); the model of the stepper motor (9) is selected, and the driving force of the stepper motor (9) along the fuselage axis direction is sufficient to overcome the resistance in the process of adjusting the wing beam spacing.

9. The spar spacing adjustment device for a morphing wing according to claim 8, characterized in that: The lead screw (7) is arranged inside the fuselage load-bearing frame (1) (near the fuselage axis position), and a corresponding slot along the fuselage axis direction is opened on the fuselage load-bearing frame (1) at a position corresponding to the connection between the lead screw nut (8) and the sliding connection support (5), and the length of the slot meets the wing beam spacing adjustment range requirement.

10. A spar spacing adjustment device for a morphing wing according to any one of claims 1 to 9, characterized in that: The operation process of the device is as follows: the stepping motor (9) drives the lead screw (7) to rotate, so that the lead screw nut (8) drives the sliding connection support (5) to move horizontally along the fuselage load-bearing frame (1); the sliding connection support (5) is connected to the movable wing beam (3) through the connecting plate (6), and pushes the movable wing beam (3) to move horizontally along the fuselage load-bearing frame (1), thereby flexibly adjusting the wing chord length according to needs.

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