RU2427502C1 - Aircraft landing gear well front flap drive - Google Patents

Abstract

FIELD: transport. ^ SUBSTANCE: invention relates to aircraft engineering. Proposed drive comprises brace made up of top and bottom links, driving two- and three-arm driven rockers, first and second rods, and two main tie rods articulated with well front flaps. Brace top link end is articulated with brace bottom link while its opposite end is articulated to aircraft fuselage by two aligned hinges and, by hinge arranged nearby plane of aircraft symmetry, it is coupled with driven rocker. Driving rocker is secured on brace top link between hinges of its joint with driven rocker and brace bottom link. One arm of driving rocker is jointed with first tie rod articulated with fuselage while another arm is coupled with second tie rod articulated with driven rocker driving arm. Note here that ends of driven rocker arranged on opposite sides of axis of aircraft symmetry are articulated with said main tie rods. ^ EFFECT: compact design, reliable extension of leg. ^ 8 cl, 11 dwg

Description

The invention relates to aircraft, and in particular to mechanisms that open and close the flaps of a landing gear niche in the process of releasing and cleaning the front landing gear.

A known mechanism for controlling the flaps of an aircraft landing gear niche, in which the flaps are controlled by a hydraulic cylinder equipped with a double-sided ball lock. Movement from the hydraulic cylinder through the gearbox is transmitted to the valves (USSR copyright certificate No. 145135, NKI 62d 1602., application form. 4.07.1960, published in the Bulletin of inventions No. 4 for 1962).

A known mechanism for controlling the wing of a landing gear of an aircraft, in which the device for mounting the wing of a wing of the landing gear includes a leaf that is rotatably connected to the structure of the aircraft, and a drive mechanism for the leaf. The axis of rotation of the support and the sash is made intersecting and located in front of the wheels of the support to ensure that the sash moves forward when the chassis is released (RF patent No. 1834190, IPC6 V64C 25/10, publ. 08/09/1995).

A known mechanism for controlling the wing of a landing gear of an aircraft, in which the rotary leaf by means of brackets is hung on a beam, fixedly mounted on the structure of the aircraft. Also on the traverse there is a hinged attachment unit for the sash drive mechanism (RF patent No. 1826417, IPC6 V64C 25/16, decl. 02.11.1991, publ. 09.08.1995).

A known mechanism for controlling a flap of a landing gear niche of an aircraft, which comprises a thrust with an axial rotation unit, pivotally mounted on a rotary unit of the wing and connected to the landing gear assembly. The chassis niche flap control mechanism is equipped with a rocking chair, one end pivotally mounted on the chassis support assembly, and the other end pivotally connected to the axial rotation assembly, the thrust axis of rotation relative to the rocking chair perpendicular to the rotation axis of the rocking tower relative to the landing gear assembly (USSR copyright certificate No. 1462654, B64 C25 / 16 2004).

The disadvantages of analogues include the fact that the transmission of movement is carried out using gearboxes and hydraulic cylinders with locks. Such devices are difficult to operate and require careful adjustment. In addition, hydraulic actuators require matching devices, which are responsible for the sequence of the process of cleaning and releasing the chassis.

The closest analogue of the claimed invention is a technical solution to the control mechanism of the hatch of the aircraft landing gear hatch, known from the USSR copyright certificate 195326 (IPC V64c, application. 05/12/1966, publ. 04/12/1967). This technical solution consists of a two-arm (intermediate) rocking chair, one arm of which is connected by a thrust to the suspension strut, the other arm is connected by a main link to the chassis niche leaf. The two-armed (intermediate) rocking chair in this solution is fixed on the fuselage of the aircraft. The sash is pivotally connected to the fuselage structure. In this solution, the hinge axes of the second thrust connection with the wing are parallel to the plane of symmetry of the aircraft. The axis of the rocking joints and the first thrust are perpendicular to the plane of symmetry of the aircraft.

When releasing the suspension strut, the first link rotates the rocking chair and, through the main link, opens the sash. When the sash is fully open, the suspension strut is in an intermediate position. With further movement of the suspension strut to the outlet, the first link turns the rocker, and the second link closes the sash. With the strut strut fully extended, the sash closes completely. When cleaning the suspension strut in a niche, the drive first opens the front flaps and then closes them.

The full opening of the chassis niche leaf using this technical solution is achieved when the suspension strut deviates from the retracted position in the chassis niche by an angle of 30 to 50 degrees. This causes the use of this solution only for relatively short landing gear, in which the front support wheel in the retracted position in the landing gear lies at a sufficiently large distance from the closed sash. However, in airplanes designed, for example, according to the low-wing plan, the front landing gear supports have an increased length and are placed in a folded position in the niche of the front landing gear with minimal gaps relative to the front flaps of the landing gear. This makes ineffective the use of this solution of the mechanism for driving the chassis flaps in a number of chassis designs. Thus, the use of such a mechanism for opening the front flaps of an aircraft landing gear with small gaps between the strut in the retracted position and the front flaps requires the use of a mechanism with small shoulders, which reduces the stiffness of the mechanism, and in the retracted position of the strut to prevent suction of the flaps and prevent deterioration the aerodynamic characteristics of the aircraft, it is necessary to install special locks on the flaps and a system for opening and closing these locks.

The technical problem solved by the claimed invention is the development of a compact mechanism for driving the front flaps of an airplane landing gear niche, connected with movable landing gear elements, which allows opening and closing the flaps when releasing the suspension strut and opening and closing it when cleaning the suspension strut into a niche with minimal gaps between a support in a position folded into a niche of the chassis and closed front flaps in combination with high rigidity of the mechanism and low weight.

The technical task is solved as follows.

The drive mechanism of the front flaps of the landing gear niche of the aircraft in accordance with the claimed solution contains a strut made up of upper and lower links, a two-arm drive and a three-arm driven rocker, a first and second link, a pair of pivotally connected to the front flaps of the landing gear of the main link. Moreover, in the claimed solution, the lower brace link is pivotally connected to the suspension strut. One end of the upper strut link is pivotally connected to the lower strut link, and its other end is attached to the aircraft fuselage by two coaxial joints spaced on opposite sides of the plane of symmetry of the aircraft and a hinge located near the plane of symmetry of the plane is connected to the driven rocking chair. In addition, in the claimed solution, the leading rocking chair is mounted on the upper link of the strut between the hinges of its connection with the driven rocking chair and with the lower link of the strut. One shoulder of the lead rocking chair is connected to the first link pivotally mounted on the fuselage, and the other shoulder is connected to the second link pivotally connected to the leading shoulder of the driven rocker. The ends of the driven shoulders of the driven rocking chair in the proposed solution are located on different sides from the plane of symmetry of the aircraft and are pivotally connected to the said main rods.

The technical result of using the proposed solution of the mechanism for driving the wing flaps of an aircraft landing gear is the possibility of creating a mechanism whose kinematic diagram provides accelerated full disclosure of the flaps of the landing gear when releasing the suspension strut at relatively small deviation angles (15 ... 25 degrees) of the suspension strut from the original retracted position in the niche the chassis and the "tightened" position of the front flaps in the fully open position with a further deviation of the strut from the complex nnogo position at an angle of 50 ... 70 degrees. This ensures the release of the suspension strut, placed in a retracted position in the chassis niche with a small gap relative to the closed position of the front flaps of the chassis niche. Design and engineering studies show that the use of the proposed solution allows you to place in the niche of the aircraft chassis with a fuselage diameter of 3 to 4 m a suspension strut from 1.7 to 2.5 m long with a pair of wheels with a diameter of 500 ... 600 mm with a gap relative to the elements of the landing gear aircraft 20 ... 30 mm. At the same time, the mechanism provides the possibility of releasing the suspension strut through the open front flaps of the niche with a gap of 15 to 25 mm between the contours of the wheelset and the open front flaps of the niche.

In addition, the location of the driven and driving rockers of the front wing drive mechanism on the upper strut link allows you to get rid of additional console bracket assemblies on the fuselage. In the claimed solution, one bracket is mounted on the fuselage for hinging the first link. In addition, the connection of the front flaps of the landing gear by means of main rods to one driven rocking chair and the placement of its driven shoulders on opposite sides of the plane of symmetry of the aircraft allows you to partially balance the forces coming from the wings during the flight of the aircraft with sliding. The stiffness of the drive and the fastening of the upper strut link are increased by two coaxial joints spaced on different sides from the plane of symmetry of the aircraft to the fuselage. These factors significantly increase the rigidity of the system, thereby reducing the mass of the mechanism by 3 ... 5% in comparison with analogues.

Most preferably, the driven shoulders of the driven rocking chair are placed almost symmetrically with respect to the plane of symmetry of the aircraft, which also reduces the mass of the mechanism.

In addition, the drive mechanism of the front flaps of the landing gear niche of the aircraft can be equipped with a lock of the retracted position, mounted on the fuselage and made possible to fix the upper brace link to the fuselage when the depreciation strut is in the retracted position. This additionally increases the stiffness of the flap mechanism in flight with the landing gear retracted and, as a result, reduces the “splitting” of flaps in flight.

In addition, the hinge for attaching the driven rocker to the upper strut link is most expedient to perform coaxial hinges for attaching the upper strut link to the fuselage, which further increases the compactness of the drive and ensures high adaptability of the structure.

Most preferably, the connection of the links of the leading rocking chair with the first and second rods is made articulated.

It is most optimal to choose the length of the strut from the range 0.7 ... 1 of the length of the suspension strut, and choose the length of the upper strut link that exceeds the length of the lower strut link by 1.75 ... 2.3 times. An increase in the linear dimensions of the strut does not make it possible to place it in a folded position in an aircraft landing gear of a limited size, smaller linear dimensions of the strut, resulting in a non-optimal load distribution, are not optimal in weight.

In this case, the distance from the hinge of the mounting of the driven rocking chair to the upper link of the strut to the hinge of the mounting of the leading rocking chair on the upper link of the strut can be selected to be 1.75 ... 2.3 times greater than the distance from the hinge of the mounting of the driving rocking chair to the hinge of fastening the upper link to the lower link of the strut. This, in combination with the choice of the optimal length of the upper strut link (see above), provides the setting of the optimal initial angular velocities from the suspension strut to the drive mechanism of the front flaps. Deviation from the specified range in the placement of the leading rocking chair on the upper link of the strut leads either to an increase in the mass of the drive, or to an increase in its dimensions.

An additional choice of the lengths of the first, second and main rods is 2.5 ... 3.5, and the shoulder lengths of the driven and driving rockers are 9 ... 11 times smaller than the length of the suspension strut, it is most preferable to provide the necessary relationships between the angle of deviation of the suspension strut from the initial the folded position and the deflection angle of the front flaps of the chassis niche and further contribute to the creation of a compact mechanism.

Design studies show the effectiveness of using the proposed solution to the drive mechanism of the front flaps of the aircraft landing gear in the aircraft structure, designed to carry from 70 to 130 passengers.

The invention is illustrated by the following materials:

figure 1 - drive mechanism with an amortization strut (isometric view, fuselage elements, niche flaps are not conventionally shown);

figure 2 is a kinematic diagram of the drive mechanism of the front flaps of the aircraft landing gear niche (depreciation strut is folded in the landing gear niche, side view);

figure 3 is a kinematic diagram of the drive mechanism of the front flaps of the aircraft landing gear niche (depreciation strut is folded in the landing gear niche, top view);

figure 4 is a kinematic diagram of the drive mechanism of the front flaps of the aircraft landing gear niche (suspension strut in the manufacturing process, side view);

5 is a kinematic diagram of the mechanism for driving the front flaps of an airplane landing gear niche (suspension strut during the release process, view against the direction of flight);

6 is a kinematic diagram of the mechanism for driving the front flaps of an airplane landing gear niche (suspension strut released, side view);

7 is a drawing of a General view of the drive mechanism of the front flaps of the aircraft landing gear niche (depreciation strut is folded in the landing gear niche, side view);

Fig. 8 is a drawing of a general view of the drive mechanism of the front flaps of an airplane landing gear niche (depreciation strut released, side view);

Fig.9 is a drawing of a General view of the drive mechanism of the front flaps of the aircraft landing gear niche (depreciation strut released, view against the direction of flight);

figure 10 is a graph of the angle of opening of the wings on the angle of release of the strut;

11 is a graph of the change in the gear ratio between the opening angle of the wings and the angle of release of the support.

The inventive drive mechanism of the front flaps of the landing gear of the aircraft is arranged as follows.

The drive mechanism of the front flaps of the landing gear of the aircraft is kinematically connected with the front landing gear of the aircraft, which includes an amortization strut 1 with a pair of wheels and a power cylinder for harvesting - releasing an amortization strut 2. The amortization strut is hinged 5 to the fuselage of the aircraft. In addition, the drive mechanism of the front flaps of the landing gear of the aircraft is kinematically connected with the front flaps 6 of the landing gear and the suspension strut - with the rear flaps of the landing gear 7.

The drive mechanism of the front flaps of the aircraft landing gear niche contains a strut, two-shoulder drive 8 and three-arm driven 9 rocking, the first 10 and second 11 rods, two main rods 12. The main rods 12 are hinged 13 connected to the front flaps 6 of the airplane landing gear. In addition, the drive mechanism of the front flaps of the chassis niche may include a lock 3 of the retracted strut position and a lock 4 of the released position.

The strut of the drive mechanism of the front landing gear is made of the upper 14 and lower 15 links, which are connected by a hinge 16. The hinge 16 is expediently made so that the strut links 14, 15 can be rotated about an axis perpendicular to the plane of symmetry 22 of the aircraft.

The lower link 15 brace pivotally connected to the suspension strut 1.

One end of the upper strut link 14 using the hinge 16 is connected to the lower strut link 15. Its other end with two coaxial hinges 17 is fixed on the fuselage of the aircraft and the hinge 18 is connected to the driven rocking chair 9.

Two coaxial hinges 17 for attaching the upper strut link to the fuselage are spaced apart on opposite sides from the plane of symmetry 22 of the aircraft, as shown in FIGS. 1, 3, 5, 9. It is most preferable to make the upper strut in the form of a flat force element in the form of an isosceles triangle (see 1, 9), having placed at the vertices adjacent to the base, the hinge assemblies 17 for attaching the upper strut link to the fuselage, and at the third vertex, the hinge fork 16 for connecting the upper and lower strut links (see Fig. 1).

The hinge 18 for securing the driven rocker 9 to the upper strut link is located near the plane of symmetry of the aircraft 22 (see FIG. 3), that is, within the design and technological tolerances accepted in the industry. When performing the upper link 14 of the strut in the form of an isosceles triangle (see Figs. 1, 3, 9), the hinge 18 for securing the driven rocking chair is expediently placed near the middle of its base. In the most preferred way of using the proposed solution to the mechanism of leaf movement, the hinge 18 for connecting the slave rocker 9 and the upper strut link 14 is advisable to perform coaxial hinges of the fastening 17 of the upper strut link to the fuselage.

The lead rocker 8 is pivotally mounted on the upper strut link 14 between the hinge 18 for attaching the driven rocker to it and the hinge 16 of its connection with the lower strut link 15, as shown in FIGS. 2, 4, 6, 7, 8.

One shoulder of the lead rocker 8 is connected to the first thrust 10, which is hinged 20 mounted on the fuselage. The other arm of the drive rocker 8 is connected by a second link 11 to the drive arm of the driven rocker 9. The arms of the drive rocker are pivotally connected to the first and second links.

The slave rocker 9 is pivotally mounted on the upper link 14, as shown in FIGS. 1, 2, 3, 9. The three-arm slave rocker 9 can be made in the form of a Y-shape, as shown in FIG. 1, 9. One of the arms of the rocker, pivotally connected to the second rod 11, is the lead, and the other two shoulders are the followers. The ends of the driven shoulders of the driven rocking chair are located on different sides of the plane of symmetry 22 of the aircraft. In the most preferred embodiment of the invention, it is advisable to place the driven shoulders of the driven rocking chair almost symmetrically with respect to the plane of symmetry of the aircraft, that is, within the design and technological tolerances accepted in the industry.

The driven shoulders of the driven rocker are hinged 19 to the main rods 12. The hinges 19 to connect the main rods to the driven rocker and the hinges 13 to connect the main rods 12 to the front flaps 6 are expediently made so that the main rods can be rotated relative to two mutually perpendicular axes. In this case, the hinges must allow the possibility of rotation of the main rods relative to one axis by an angle of ± 80 ... 90 degrees, and relative to the other axis by a small angle within ± 7 ... 9 degrees.

The lock 3 of the retracted strut position (see Fig. 7) is configured to fix the upper strut link 14 to the aircraft fuselage in the retracted position of the strut. The lock 4 of the released position can be made with the possibility of fixing the strut in the unfolded position when the released position of the suspension strut.

When using the proposed solution in the design of an aircraft designed according to the low-wing plan, designed to carry from 75 to 130 passengers, the length of the suspension strut can be from 1.7 to 2.5 m. At the same time, the length of the strut is most appropriate to choose from a range of 0.7 up to 1 from the length of the suspension strut, and choose the length of the upper brace link exceeding the length of the lower brace link by 1.75 ... 2.3 times. It is most preferable to choose the distance from the hinge of fastening the driven rocking chair to the upper link of the strut to the hinge of fastening the leading rocking chair at the upper link of the brace 1.75 ... 2.3 times exceeding the distance from the hinge of fastening the leading rocking chair to the hinge of fastening the upper link to the lower link of the strut. In this case, the lengths of the first, second and main rods can be selected in 2.5 ... 3.5, and the lengths of the shoulders of the driven and leading rocking chairs - 9 ... 11 times less than the length of the suspension strut.

The rear part of the chassis niche in the retracted position of the chassis is closed by the rear flaps 7 of the niche. The rear flaps 7 are pivotally connected by rods of the rear flaps 21 to the suspension strut 1.

The inventive drive mechanism of the front flaps of the landing gear of the aircraft operates as follows.

In the retracted position, the strut 1 and strut are removed in the niche of the aircraft chassis. At the same time, the upper strut link 14 is fixed in the lock 3 of the retracted position, eliminating the possibility of moving elements of the drive mechanism of the front flaps of the aircraft landing gear niche in flight. In this case, both the front 6 and rear 7 flaps of the chassis niche are closed (see Fig. 2, 3, 7).

When the depreciation strut 1 is released, the lock 3 of the retracted position is opened, the depreciation strut under the action of the power cylinder 2 begins to unfold relative to the axis of the hinge 5, while it begins to unfold the upper 14 and lower 15 links relative to each other relative to the axis of the hinge 16 (see Fig. 4, 5). The leading rocking chair 8, connected to the first link 10, starts to rotate around its own axis and, in addition, its hinge for attaching to the upper strut link begins to move together with the upper strut link 14. The lead rocker 8 through the second link 11 transmits the movement to the driven rocker 9. Thus, the total movement from the top link 14 of the strut and the movement of the lead rocker 8 around its own axis are transmitted to the driven rocker 9. With the slave rocker 9 through the main link 12, the movement is transmitted to the front flaps 6 of the chassis niche. The front wings begin to open.

When the suspension strut deviates from the initial position 23 in the chassis niche to the angle ά = 15 ... 25 degrees (see Figs. 4, 5, 9), the front flaps of the niche deviate from the closed position 24 by an angle β = 85 ... 90 degrees, that is, up to fully open position (see figure 4, 5).

With a further deviation from the initial (retracted into the niche) position of the suspension strut to ά = 60 ... 70 degrees, the flaps are in the fully open position, which ensures the movement of the suspension strut with a wheel pair with sufficient gaps between the open front flaps of the chassis niche.

With a further deviation of the suspension strut from the initial position by an angle α = 95 ... 100 degrees to the final position, the front flaps 6 of the landing gear are closed (see Fig.6, 9). The strut is fixed in the unfolded position by the lock 4 of the released position of the suspension strut.

In the process of releasing the suspension strut, the rear flaps of the chassis niche connected by rods 22 to the suspension strut open.

When cleaning the suspension strut, the strut is folded, the exhaust cleaning drive rotates the suspension strut around the axis of the hinge 5. The movement from the top link 6 of the strut through the drive is transmitted to the front flaps 1, 2 and they first open, pass the support, and then close.

During the cleaning of the suspension strut, the rear flaps of the chassis niche are closed.

In the retracted position of the support, the upper strut link becomes locked in the retracted position, making it impossible to move the drive rocker of the sash drive mechanism.

The effectiveness of the proposed solution to the drive mechanism of the front flaps of the aircraft landing gear niche is illustrated by the graphs shown in Fig.10-11. When the suspension strut deviates from the retracted position 23 (see Fig. 4, 5) by an angle α = 15 ... 25 degrees, the front flaps deviate by an angle β = 85 ... 90 degrees. The gear ratio in this case (see Fig. 11) quickly changes from significant values to zero. With a further deviation of the strut to angles α = 60 ... 70 degrees, the front flaps remain in the open position, the gear ratio is almost zero. With a further deviation of the depreciation strut from the position folded into the niche in the range of angles from 70 to 100 degrees, the flaps quickly close, the gear ratio sharply increases (in absolute value) from values close to zero to significant values. The design of the mechanism ensures its compact placement in the niche of the aircraft, together with an amortization strut with a length of 1.7 to 2.5 m with a diameter of the wheelset of 500 ... 700 mm with minimal gaps relative to the elements of the niche. During the release and cleaning of the suspension strut, the design ensures the opening and closing of the front flaps and the movement of the suspension strut with a pair of wheels between the open front flaps with gaps of 15 to 25 mm.

Claims (8)

1. The drive mechanism of the front flaps of the landing gear niche of the aircraft, comprising a strut made up of upper and lower links, a two-arm drive and a three-arm driven rocker, a first and second link, and a pair of pivotally connected to the front flaps of the landing gear niche of the main rods, while the lower brace link is pivotally connected to the suspension strut, one end of the upper strut link is pivotally connected to the lower strut link, and its other end is fixed with two coaxial joints spaced on opposite sides of the plane of symmetry of the aircraft on the aircraft fuselage, and a hinge located near the plane of symmetry of the aircraft, is connected to the driven rocker, the leading rocker is mounted on the upper strut link between the hinges of its connection with the driven rocker and the lower strut link, while one shoulder of the driving rocker is connected to the first link, pivotally mounted on the fuselage, and the other arm is connected to a second thrust pivotally connected to the driving arm of the driven rocker, the ends of the driven arms of the driven rocker located on different sides of the plane of symmetry of the aircraft, pivotally connected to said main rods. 2. The drive mechanism of the front flaps of the aircraft landing gear niche according to claim 1, characterized in that the driven shoulders of the driven rocking chair are placed almost symmetrically with respect to the plane of symmetry of the aircraft. 3. The mechanism for driving the front flaps of an aircraft landing gear niche according to claim 1, characterized in that it is equipped with a retracted lock secured to the fuselage and made possible to fix the top brace link to the fuselage when the suspension strut is in the retracted position. 4. The drive mechanism of the front flaps of the aircraft landing gear niche according to claim 1, characterized in that the hinge for connecting the driven rocker and the upper strut link is aligned with the hinges of the upper strut link to the fuselage. 5. The drive mechanism of the front flaps of the aircraft landing gear niche according to claim 1, characterized in that the drive rocker is pivotally connected to the first and second rods. 6. The drive mechanism of the front flaps of the aircraft landing gear niche according to claim 1, characterized in that the strut length is selected from a range of 0.7 ... 1 from the length of the suspension strut, and the length of the upper strut link is selected to exceed the length of the lower strut link of 1.75 ... 2 ,3 times. 7. The drive mechanism of the front flaps of the aircraft landing gear niche according to claim 6, characterized in that the distance from the hinge of the driven rocking chair to the upper link of the strut to the hinge of the driving rocker at the upper link of the strut is chosen to exceed the distance from the hinge of the driving rocker to the upper link hinge to the lower link of the strut 1.75 ... 2.3 times. 8. The drive mechanism of the front flaps of the aircraft landing gear niche according to claim 7, characterized in that the lengths of the first, second and main rods are selected at 2.5 ... 3.5, and the lengths of the shoulders of the driven and driving rockers are 9 ... 11 times less than the length depreciation rack.

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