A variable camber six-bar trailing edge structure applicable to supercritical wings

Abstract

The present invention relates to a variable-camber six-bar trailing-edge structure applicable to a supercritical wing, belonging to the technical field of aircraft structures. The variable-camber trailing-edge mechanism includes three parts: a deformed wing rib group, a drive structure group, and a support group. In the present invention, the trailing edge of the wing is deflected downward in three sections to achieve the change of the airfoil camber. Through the integrated design of the Watt six-bar mechanism and the Stephen six-bar mechanism, it is ensured that the trailing edge can be accurately and continuously deflected downward in a narrow space. Since the six-bar mechanism has the advantages of large load transmission and easy guarantee of manufacturing and assembly accuracy, the variable-camber six-bar trailing-edge mechanism has the advantages of large aerodynamic load-bearing capacity and high reliability. At the same time, it belongs to a single-degree-of-freedom system and can stay in the initial deflected state, the fully deflected state, and any intermediate state, belonging to smooth and continuous deformation. The present invention has the advantages of compact structure, large aerodynamic load-bearing capacity, high reliability, and all drive mechanisms being located inside the airfoil, and is applicable to the narrow trailing edges of modern aircraft wings such as supercritical airfoils.

Description

Technical Field

[0001] The present invention relates to a variable camber six-bar trailing edge structure applicable to a supercritical wing. The trailing edge is designed based on the principles of the Watt mechanism and the Stephenson mechanism in the six-bar mechanism, and is applicable to the variable camber structure design of the supercritical wing of modern civil aircraft, belonging to the technical field of aircraft structures. Background Art

[0002] During flight, the variable camber trailing edge changes the camber of the airfoil to achieve adaptive downward deflection, which is an important technical way for modern civil aircraft to improve takeoff and landing, cruise performance, increase aerodynamic efficiency, and reduce fuel consumption rate, and has great potential in improving the aerodynamic characteristics of civil airliners. Compared with the discrete downward deflection of the traditional trailing edge flap and aileron, the variable camber trailing edge can achieve continuous downward deflection, enabling the trailing edge to be fixed at any intermediate position of dynamic downward deflection, matching the optimal lift-drag requirements of flight, and maintaining the optimal aerodynamics throughout the cruise section. In addition, the wing surface drive of the traditional flap and aileron generally uses a slide rail and guide groove structure, which is usually exposed outside the airfoil and is wrapped with a fairing to reduce the influence of the irregular shape on the lift-drag characteristics. The drive mechanism of the variable camber trailing edge is completely hidden inside the airfoil, maintaining a smooth shape during deformation, without the seams and scissor openings of the traditional flap and aileron structure, which can reduce flow separation and reduce takeoff and approach noise. As far as possible, the known variable camber structure schemes such as the fishbone type and the eight-link type can only be applied to small aircraft, use complex deformation structures or intelligent materials for drive, cannot withstand the aerodynamic loads in the subsonic high Mach number state, and it is also difficult to arrange the structure for the long and narrow trailing edge of the modern aircraft supercritical airfoil. The present invention uses the Watt type I mechanism in the six-bar linkage as the trailing edge deformation structure, responsible for the downward deflection movement of the trailing edge component; uses the Stephen type III mechanism in the six-bar linkage as the deformation drive structure, responsible for driving the entire structure. By combining the two mechanisms, a single-degree-of-freedom mechanism is formed, which can be arranged in a long and narrow space, and has the advantages of compact structure, large drive load-bearing capacity, and simple structure. The present invention designs the motion points of the mechanism, so that the variable camber six-bar single-redundancy mechanism of the trailing edge has a failure protection ability, improving the reliability and engineering applicability of the trailing edge variable camber structure. Summary of the Invention

[0003] The object of the present invention is to design a large trailing edge variable camber mechanism that can withstand aerodynamic loads in the high subsonic state. Aiming at the problems of the existing fishbone type variable camber trailing edge with weak load-bearing capacity, low reliability, and inapplicability to large long-range civil aircraft, a variable camber trailing edge mechanism scheme based on six-bar drive is proposed. The drive part has a compact structure and a large deformation angle of the mechanism, and has important application value in the field of variable camber trailing edge structure design of wings.

[0004] The idea of the present invention is to achieve the change of airfoil camber by the downward deflection of the three-segment structure at the trailing edge of the wing. Through the integrated design of the Watt six-bar mechanism and the Stephen six-bar mechanism, it is ensured that the trailing edge can be accurately and continuously deflected downward in a narrow space. Since the six-bar mechanism has the advantages of large load transmission and easy guarantee of manufacturing and assembly accuracy, the variable-camber six-bar trailing edge mechanism has the advantages of large aerodynamic load-bearing capacity and high reliability. At the same time, it belongs to a single-degree-of-freedom system and can stay in the initial downward deflection state, the fully downward deflection state, and any intermediate state, belonging to smooth and continuous deformation.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] A variable-camber six-bar trailing edge structure applicable to a supercritical wing, comprising a deformed wing rib group, a drive structure group, and a support group; the deformed wing rib group is a Watt-type six-link structure, and the first group of wing ribs, the second group of wing ribs in the deformed wing rib group, and the drive structure group constitute a Stephen-type six-link structure; the drive structure group of the Stephen-type six-link structure adopts an eccentric wheel and a pull rod design. The overall structure composed of the Watt-type six-link and the Stephen-type six-link belongs to a single-degree-of-freedom mechanism, with ten nodes and eight links. By rotating the drive shaft 108 of the drive structure group, the overall mechanism deflects downward, pulling the second group of wing ribs to deflect downward as a whole. The drive shaft 108 is connected to the support group through bearings.

[0007] The deformed wing rib group includes a first group of wing ribs, a second group of wing ribs, a third group of wing ribs, and a bent link 104 and a straight link 105; the first group of wing ribs includes a first group of left wing ribs 101a and a first group of right wing ribs 101b, the second group of wing ribs includes a second group of left wing ribs 102a and a second group of right wing ribs 102b, and the third group of wing ribs includes a third group of left wing ribs 103a and a third group of right wing ribs 103b; each group of two wing ribs in the deformed wing rib group is symmetric, and the three groups of wing ribs are connected by pin shafts. When rotating around the shaft, the shape of the wing ribs represents the shape of the trailing edge of the wing. The first group of wing ribs and the third group of wing ribs are connected by a straight link 105; the second group of wing ribs is connected to the drive rod 106, and one end of the bent link 104 is connected to the support group and the other end is connected to the second group of wing ribs.

[0008] The length of each group of wing ribs accounts for 20%-50% of the entire trailing edge length.

[0009] The drive structure group includes a drive rod 106, an eccentric wheel 107, and a drive shaft 108; the drive rod 106 is connected to the second group of wing ribs through a pin shaft, and the connection point is below the neutral line of the second group of wing ribs; the drive rod 106 is connected to the eccentric wheel 107 through a bearing; the eccentric wheel 107 is connected to the drive shaft 108 through a flat key; the drive shaft 108 is connected to the inner side support 109 of the support group through a bearing.

[0010] The support group includes side supports 109, intermediate supports 110, and trailing edge beams 111; the side supports 109 and the intermediate supports 110 are fixed on the trailing edge beams 111.

[0011] The structure of the intermediate support 110 has two connection points. The upper connection point is connected to the first group of wing ribs through a pin shaft, and the lower connection point is connected to the second group of wing ribs through a bent connecting rod 104 and a pin shaft.

[0012] When the trailing edge moves downward, the drive shaft 108 rotates to drive the eccentric wheel 107 to rotate. The eccentric wheel 107 is connected through a bearing and drives the drive rod 106 to move, thereby driving the second group of wing ribs to move, so as to achieve the overall downward deflection of the variable-shaped wing rib group and achieve the effect of changing the camber of the wing trailing edge.

[0013] The variable-camber six-bar trailing edge structure has only one degree of freedom and is controlled by a single drive of the drive shaft 108.

[0014] Advantages of the present invention

[0015] 1. The variable-camber trailing edge has only one degree of freedom and is controlled by a single drive of the drive shaft, which can make the trailing edge deformation stay at the desired angle, ensuring the reliability of the structure and the simplicity of the drive.

[0016] 2. The drive structure group adopts the design of eccentric wheels and pull rods to pull the second group of wing ribs for overall downward deflection. Such a design can make all the structures of the drive structure group close to the wing ribs, ensuring that they can be integrated into the trailing edge airfoil.

[0017] 3. The overall structure of the trailing edge adopts a symmetric design. The wing ribs, drive rods, and eccentric wheels all have a unified symmetry plane, which can eliminate out-of-plane bending moments and do not require external structures to transmit loads, facilitating the design of other structures of the trailing edge.

[0018] 4. The combination of Watt-type six-bar linkages and Stephen-type six-bar linkages and the design of points can make full use of space and meet the strict requirements of the aircraft for space utilization.

[0019] 5. The drive mechanism based on the Stephen mechanism can achieve a failure locking function through the design of each mechanism point. When the drive shaft fails and loses its driving ability, it can ensure that the trailing edge structure of the aircraft maintains a certain upward-deflected airfoil and a large lift coefficient.

[0020] In summary, the present invention enables the variable-camber trailing edge structure to not only withstand large aerodynamic loads but also meet the requirements of the narrow and long shape of the supercritical airfoil trailing edge form. Moreover, the overall structure has a single degree of freedom, is convenient and simple to drive, and has high reliability. In addition, since no intelligent materials such as shape memory alloys are used, it is reusable and easy to maintain. Description of the drawings

[0021] Figure 1It is a schematic diagram of the downward deflection of the three-segment trailing edge with variable camber adopted by the present invention;

[0022] Figure 2 It is a schematic diagram of a variable-camber six-bar trailing edge structure applicable to a supercritical wing;

[0023] Figure 3 It is a schematic diagram of the connection between the middle support, the bent connecting rod and the first group of left wing ribs;

[0024] Figure 4 It is a schematic diagram of the initial state of the variable-camber trailing edge mechanism of the present invention;

[0025] Figure 5 It is a schematic diagram of the downward deflection state of the variable-camber trailing edge mechanism of the present invention;

[0026] Figure 6 Schematic diagram of the principle of the variable-camber six-bar trailing edge framework applicable to a supercritical wing;

[0027] Figure 7 Schematic diagram of the principle of the trailing edge downward deflection mechanism based on the Watt mechanism (solid line part);

[0028] Figure 8 Schematic diagram of the principle of the trailing edge drive mechanism based on the Stephen mechanism (solid line part);

[0029] Figure 9 Design principle of the trailing edge drive mechanism with failure locking ability.

[0030] Among them: 101a - the first group of left wing ribs, 101b - the first group of right wing ribs, 102a - the second group of left, 102b - the second group of right wing ribs, 103a - the third group of left wing ribs, 103b - the third group of right wing ribs, 104 - the bent connecting rod, 105 - the straight connecting rod, 106 - the drive rod, 107 - the eccentric wheel, 108 - the drive shaft, 109 - the side support, 110 - the middle support, 111 - the trailing edge beam. Specific implementation manner

[0031] The following is a detailed description of the present invention with reference to the accompanying drawings and embodiments.

[0032] A variable-camber six-bar trailing edge structure applicable to a supercritical wing, which realizes the change of the airfoil camber by the downward deflection of the three-segment structure of the trailing edge of the wing. The Watt six-bar mechanism and the Stephen six-bar mechanism are integrated in the design to ensure that the trailing edge can be accurately and continuously deflected downward in a narrow space. The downward deflection of the three segments of the variable-camber trailing edge is as follows Figure 1 Shown. The length ratio of the three trailing edge segments is restricted by the middle downward deflection state and the fully downward deflection state of the trailing edge. Adjust the length ratio to make the overall shape after the movement of the wing ribs close to the target downward deflection shape. The length of each of the three trailing edge segments accounts for 20% - 50% of the trailing edge structure.

[0033] As Figure 1As shown in the figure, the camber six-bar trailing edge structure of the present invention includes a deformable rib group, a drive structure group, and a support group; the deformable rib group is a Watt-type six-link structure, and the first group of ribs, the second group of ribs, and the drive structure group in the deformable rib group constitute a Stephen-type six-link structure; the drive structure group of the Stephen-type six-link structure adopts an eccentric wheel and a pull rod design. The overall structure composed of the Watt-type six-link and the Stephen-type six-link belongs to a single-degree-of-freedom mechanism, with ten nodes and eight links. By rotating the drive shaft 108 of the drive structure group, the overall mechanism deflects downward, pulling the second group of ribs to deflect downward as a whole. The drive shaft 108 is connected to the support group through a bearing. Such a design can place all the structures of the drive system close to the ribs, ensuring that they can be integrated within the trailing edge airfoil and is suitable for the design of supercritical wings.

[0034] The deformable rib group includes a first group of ribs, a second group of ribs, a third group of ribs, and a bent link 104 and a straight link 105; the first group of ribs includes a first group of left ribs 101a and a first group of right ribs 101b, the second group of ribs includes a second group of left ribs 102a and a second group of right ribs 102b, and the third group of ribs includes a third group of left ribs 103a and a third group of right ribs 103b; each group of two ribs in the deformable rib group is symmetrical, and the three groups of ribs are connected by pin shafts. When rotating around the shaft, the rib profile represents the trailing edge profile of the wing. The first group of ribs and the third group of ribs are connected by a straight link 105; the second group of ribs is connected to the drive rod 106, and one end of the bent link 104 is connected to the support group and the other end is connected to the second group of ribs.

[0035] The length of each group of ribs accounts for 20%-50% of the entire trailing edge length. Adjust the length ratio of each group of ribs according to the target deformation state of the trailing edge.

[0036] The drive structure group includes a drive rod 106, an eccentric wheel 107, and a drive shaft 108; the drive rod 106 is connected to the second group of ribs through a pin shaft, and the connection point is below the neutral line of the second group of ribs; the drive rod 106 is connected to the eccentric wheel 107 through a bearing; the eccentric wheel 107 is connected to the drive shaft 108 through a flat key; the drive shaft 108 is connected to the inner side support 109 of the support group through a bearing.

[0037] The support group includes side supports 109, intermediate supports 110, and a trailing edge beam 111; the side supports 109 and the intermediate supports 110 are fixed on the trailing edge beam 111.

[0038] The structure of the intermediate support 110 has two connection points. The upper connection point is connected to the first group of ribs through a pin shaft, and the lower connection point is connected to the second group of ribs through the bent link 104 and a pin shaft.

[0039] When the trailing edge moves downward, the drive shaft 108 rotates to drive the eccentric wheel 107 to rotate. The eccentric wheel 107 is connected by a bearing and drives the drive rod 106 to move, thereby driving the second set of wing ribs to move, so as to achieve the overall downward deflection of the deformable wing rib group and achieve the effect of changing the camber of the wing trailing edge.

[0040] The variable-camber six-bar trailing edge structure has only one degree of freedom and is controlled by a single drive of the drive shaft 108. It can keep the trailing edge deformation at the desired angle, ensuring the reliability of the structure and the simplicity of the drive.

[0041] The drive mechanism based on the Stephen mechanism can achieve a failure locking function. When the drive shaft fails and cannot perform drive control, the remaining structure can ensure that the trailing edge of the aircraft maintains a certain upward deflected airfoil and a large lift coefficient.

[0042] Its working principle is as follows: The variable-camber trailing edge structure is designed based on the Watt-type six-link and Stephen-type six-link. The Watt-type six-link part is used to maintain the deformation of the trailing edge wing surface, dividing the entire trailing edge into three rotating blocks to achieve the change of camber; the Stephen-type six-link part is used to drive the Watt six-link, and the whole mechanism deflects downward by driving the rotation of the drive shaft. Structurally, the drive shaft drives the eccentric wheel to rotate, pulling the drive shaft to move backward. Under the pulling of the drive rod, the second set of wing ribs achieve the downward deflection of the overall trailing edge structure. The drive shaft and the eccentric wheel need to be as close to the wing ribs as possible to ensure that the structure does not exceed the outside of the airfoil.

[0043] The positions of the nodes of the Watt-type six-link and the Stephen-type six-link can be optimized according to the target shape of the trailing edge to achieve the compact and reasonable structure and the transmission of the bearing moment.

[0044] The variable-camber six-bar trailing edge structure of the present invention is as Figure 2 shown, and is composed of the first set of left wing ribs 101a, the first set of right wing ribs 101b, the second set of left 102a, the second set of right wing ribs 102b, the third set of left wing ribs 103a, the third set of right wing ribs 103b, the bent connecting rod 104, the straight connecting rod 105, the drive rod 106, the eccentric wheel 107, the drive shaft 108, the side support 109, and the middle support 110. The overall structure is fixed on the trailing edge beam 111. The connection methods of the middle support 110, the bent connecting rod 104, and the first set of left wing ribs 101a in the support group are as Figure 3 shown, and are all connected by pin shafts.

[0045] The initial state and the final downward deflection state of the variable-camber trailing edge mechanism are as Figure 4 and Figure 5 shown. The principle of the variable-camber six-bar trailing edge framework is as Figure 6As shown, there are a total of ten key skeleton nodes, namely A, B, C, D, E, F, G, I, J, K, and one auxiliary node H. Among them, the first group of left wing ribs 101a and the first group of right wing ribs 101b are simplified to the skeleton A0B1E1 in the figure, the second group of left wing ribs 102a and the second group of right wing ribs 102b are simplified to the skeleton B1I1C1F1 in the figure, the third group of left wing ribs 103a and the third group of right wing ribs 103b are simplified to the skeleton C1G1 in the figure, the bent connecting rod 104 is simplified to the skeleton D0F1, the straight connecting rod 105 is simplified to the skeleton E1G1, the driving rod 106 is simplified to the skeleton I1J1, the eccentric wheel 107 is simplified to the skeleton J1K0, the driving shaft 108 and the side support 109 are simplified to the fixed point K0, the middle support 110 is simplified to the fixed point D0, and the entire skeleton forms a single-degree-of-freedom system. Figure 6 Two downward deflection states are identified in it. A0, B1, C1, D0, E1, F1, G1, H1, I1, J1, K0 are the initial states, and A0, B2, C2, D0, E2, F2, G2, H2, I2, J2, K0 are the positions after downward deflection. This mechanism is a single-degree-of-freedom mechanism with ten nodes and eight connecting rods. By rotating the driving shaft 108, the overall mechanism deflects downward.

[0046] The skeleton principle of the present invention consists of two parts, namely, the trailing edge downward deflection mechanism based on the Watt mechanism forms the skeleton line as Figure 7 shown by the solid line and the trailing edge driving mechanism based on the Stephen mechanism forms the skeleton line as Figure 8 shown by the solid line. Both the downward deflection mechanism and the driving structure are connected by seven nodes and six connecting rods.

[0047] The driving mechanism based on the Stephen mechanism can achieve the failure locking function through the design of each mechanism point. As follows Figure 9 shown, when the driving rod 106 and the eccentric wheel 107 are on the same axis, the entire trailing edge is in the maximum upward deflection state. When the driving shaft fails and cannot perform driving control, it can ensure that the trailing edge structure of the aircraft maintains a certain upward deflection airfoil and a large lift coefficient. That is, through this design, the overall safety is improved, and when the drive fails, it can ensure that under the external aerodynamic load, the overall structure locks the maximum upward deflection angle.

[0048] The above is the preferred embodiment of the present invention, and the present invention should not be limited to the content disclosed in this embodiment and the drawings. Any equivalent or modification completed without departing from the spirit disclosed by the present invention falls within the protection scope of the present invention.

Claims

1. A variable camber six-bar trailing edge structure applicable to a supercritical wing, characterized in that, It includes a deformable wing rib group, a drive structure group, and a support group; the deformable wing rib group is a Watt-type six-link structure, and the first group of wing ribs, the second group of wing ribs, and the drive structure group in the deformable wing rib group form a Stephen-type six-link structure; the drive structure group of the Stephen-type six-link structure adopts an eccentric wheel and a pull rod design, and the overall structure composed of the Watt-type six-link and the Stephen-type six-link belongs to a single-degree-of-freedom mechanism, with ten nodes and eight links; the drive structure group includes a drive rod (106), an eccentric wheel (107), and a drive shaft (108); the drive rod (106) is connected to the second group of wing ribs through a pin shaft, and the connection point is located below the neutral line of the second group of wing ribs; the drive rod (106) is connected to the eccentric wheel (107) through a bearing; the eccentric wheel (107) is connected to the drive shaft (108) through a flat key; the drive shaft (108) is connected to the inner side support (109) of the support group through a bearing, and by rotating the drive shaft (108) of the drive structure group, the overall mechanism deflects downward, pulling the second group of wing ribs to deflect downward as a whole.

2. The variable camber six-bar trailing edge structure applicable to a supercritical wing according to claim 1, characterized in that, The deformable wing rib group includes a first group of wing ribs, a second group of wing ribs, a third group of wing ribs, and a bent link 104 and a straight link 105; the first group of wing ribs includes a first group of left wing ribs (101a), a first group of right wing ribs (101b), the second group of wing ribs includes a second group of left wing ribs (102a), a second group of right wing ribs (102b), the third group of wing ribs includes a third group of left wing ribs (103a), a third group of right wing ribs (103b); each group of two wing ribs in the deformable wing rib group is symmetric, and the three groups of wing ribs are connected by pin shafts. When rotating around the axis, the shape of the wing ribs represents the shape of the trailing edge of the wing. The first group of wing ribs and the third group of wing ribs are connected by a straight link (105); the second group of wing ribs is connected to the drive rod (106), one end of the bent link (104) is connected to the support group, and the other end is connected to the second group of wing ribs.

3. The variable camber six-bar trailing edge structure applicable to a supercritical wing according to claim 1, characterized in that, The length of each group of wing ribs accounts for 20%-50% of the entire trailing edge length.

4. The variable camber six-bar trailing edge structure applicable to a supercritical wing according to claim 1, characterized in that, The support group includes side supports (109), intermediate supports (110), and a trailing edge beam (111); the side supports (109) and the intermediate supports (110) are fixed on the trailing edge beam (111).

5. The variable camber six-bar trailing edge structure applicable to a supercritical wing according to claim 4, characterized in that, The structure of the intermediate support (110) has two connection points. The upper connection point is connected to the first group of wing ribs through a pin shaft, and the lower connection point is connected to the second group of wing ribs through a bent link (104) and a pin shaft.

6. The variable camber six-bar trailing edge structure applicable to a supercritical wing according to claim 1, characterized in that, During the downward deflection movement of the trailing edge, the drive shaft (108) rotates to drive the eccentric wheel (107) to rotate. The eccentric wheel (107) is connected through a bearing and drives the drive rod (106) to move, thereby driving the second group of wing ribs to move.

7. The variable camber six-bar trailing edge structure applicable to a supercritical wing according to claim 1, characterized in that, The variable camber six-bar trailing edge structure has only one degree of freedom and is controlled by a single drive of the drive shaft (108).

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