JPS5810277B2 - High lift device for aircraft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-lift device for an aircraft, and particularly to a leading-edge high-lift device for an aircraft having a pylon projecting obliquely from the lower surface of a main wing.

For fixed-wing aircraft, technology to reduce stall speed is extremely important in order to improve safety during takeoff and landing and to shorten the required runway length.

For this reason, various high-lift devices have been developed and put into practical use, one of which is a leading-edge high-lift device.

On the other hand, in fixed-wing aircraft, various mounted items such as engine bots and tanks are often suspended from the underside of the main wing, and this suspension is performed via pylons.

Pylons usually protrude obliquely from the lower surface of the main wing, so if a main wing with this type of pylon is equipped with leading edge high lift devices such as leading edge flaps or leading edge slats, the pylon and This leading edge high-lift device must be cut out in the area of interference.

By the way, this leading edge high lift device moves from the raised position to the lowered position, and vice versa, in a direction approximately perpendicular to the leading edge of the main wing. In the case of an aircraft with a leading edge high-lift device, the moving direction of the leading edge high-lift device has a geometrical relationship that diagonally intersects the center plane in the longitudinal direction of the pylon, and the width of the notch in the leading edge high-lift device must necessarily be widened. You won't get any more.

When a leading edge high-lift device equipped with such a notch is in operation, as the angle of attack increases, the flow blown up from the side of the pylon passes through the notch and forms a strong vortex on the upper surface of the main wing. flow, promotes separation of the flow on the upper surface of the main wing,
This will speed up the stall.

That is, the conventional leading edge high lift device with a notch has the disadvantage that the stall angle of attack is smaller and therefore the maximum lift coefficient is also smaller than that of an ideal shape without the notch.

Therefore, in order to secure the desired stall speed with conventional leading edge high-lift devices, it is necessary to take measures such as increasing the main wing area or making the high-lift device larger. In order to take these measures, we will have to accept factors that lead to deterioration in takeoff and landing performance, such as increased weight and decreased lift-to-drag ratio.

An object of the present invention is to solve the above-mentioned drawbacks in a leading edge high-lift device having a notch as described above, and to suppress the tendency for premature stalling with a simple structure.

That is, the present invention provides an aircraft having a pylon projecting obliquely from the lower part of the main wing, and for which a notch is formed in the leading edge high-lift device. A small wing is provided that extends along the leading edge of the main wing.

The invention is applicable to any type of leading edge high lift device.

Further, it is preferable that the winglet plate is arranged so that a slot is formed between it and the leading edge of the main wing in its operating position, but the present invention naturally also includes an arrangement in which no slot is formed.

The winglet is housed in the main wing or pylon in its inactive state.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, in FIGS. 1 to 3, an engine body 3 is supported on the lower surface 2 of the main wing 1 by a pylon 4 that projects obliquely from the lower surface 2. ing.

A leading edge flap 5 is attached to the leading edge of the main wing 1 as a leading edge high lift device, and this leading edge flap 5 is stored in a recess 6 provided at the lower part of the leading edge of the main wing 1 when not in use. can do.

That is, the leading edge flap 5 has a front part 7 and a rear part 8 which are foldably connected to each other by a hinge, and as shown in FIGS.
It can be folded up and stored in the recess 6.

What is shown is a part of the left wing of the aircraft, and the leading edge of the main wing has a swept angle, as is clear from FIG.

Since the leading edge flap 5 is retracted in a direction substantially perpendicular to the leading edge of the main wing 1 having the swept angle, it is housed in the recess 6.
A notch is provided near the pylon 4 as shown in FIGS. 1 and 2 to prevent interference with the pylon 4 that supports the engine body 3.

That is, the leading edge flap 5 is divided into an inner sailing part 5a and an outer sailing part 5b, and a cutout part 10 is formed between them.

A small wing plate, that is, a small flap 11 is arranged in this notch 10 across its width.

This small flap 11 has a width that does not interfere with the pylon 4 in the illustrated lowered position, and its length is approximately the same as the width of the notch 10.

In this example, the small flap 11 has an upper surface shape that substantially follows the upper surface shape of the leading edge flap 5, and is supported by an arm 14 that can be freely taken in and out along a rail 15.

The operation of the small flap 11 is linked to the operation of the leading edge flap 5, and when the leading edge flap 5 is moved to the lowered position, the small flap 11 is also brought to the lowered position.

4 through 6 show other embodiments of the present invention, the construction of which is substantially the same as that shown in FIGS. 1 through 3.

In this example, a small flap 11 is attached to the side of the pylon 4.
A recess 12 is provided for storing the small flap 11.
is moved by a suitable linkage or hinge mechanism between an inoperative position, housed in this recess 12, and an operative position, shown in solid lines in the figure.

For example, as shown in FIG. 7, the small flap 11 is rotatably supported by an arm 11a around a hinge 16 on the pylon 4, and is accommodated in the recess 12.

8 and 9 show an example in which the present invention is applied to an aircraft having leading edge slats. A slat 105 is provided at the leading edge of a main wing 101, and this slat 105 mounts an engine 103. It consists of an inner section 105a and an outer section 105b separated by the pylon 104.

The slat 105 has a shape that forms the leading edge of the main wing 101 in the retracted position as shown by the chain line in the figure, and can be made to protrude from the retracted position as shown by the solid line.

A notch 110 is formed between the inner and outer side portions 105a and 105b of the slat, as in the previous example, and a small wing plate 111 is provided in this notch 110, as in the previous example.

This small wing plate 111 is connected to the main wing 101 as shown by the chain line in the figure.
It can be pulled inside.

FIG. 10 is a chart showing the stall characteristics of a wing equipped with a wing plate according to the present invention. As is clear from this chart, the wing with a notch in the leading edge high-lift device has an ideal shape without a notch. The stall begins at a significantly lower angle of attack compared to the blades of the present invention, whereas with the winglet of the present invention, the stall is delayed to a point almost similar to that of an unnotched blade.

In particular, when a wing plate having a chord length of 55 times the chord length of the leading edge high-lift device is provided, its stall characteristics are improved to the extent that it is almost as good as that of one without a notch.

In carrying out the invention, it is preferred that a slat is formed between the winglet and the main wing leading edge in the operating or lowered position of the leading edge high lift device.

That is, the formation of this slot provides a boundary layer control effect and suppresses separation of airflow over the upper surface of the main wing.

FIG. 11 shows the effect.

If such a slot is not formed between the winglet plate and the leading edge of the main wing, the effect of suppressing separation due to the slot cannot be obtained, but the advantage of reducing drag at a low angle of attack can be obtained.

As explained above, in the present invention, a small blade plate is provided in the notch of the leading edge high lift device formed in the main wing pylon to prevent the generation of vortices in the airflow at this notch. Therefore, the stall can be significantly delayed compared to a wing equipped with a conventional leading edge high lift device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a wing having a leading edge flap showing an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG.
-■ line sectional view, Figure 4 is a perspective view showing another embodiment, Figure 5 is a perspective view showing another embodiment.
The figure is a plan view of FIG. 4, FIG. 6 is a cross-sectional view taken along the line ■-■ of FIG. 5, FIG. 7 is a cross-sectional view taken along the line ■-■ of FIG. 6, and FIG. FIG. 9 is a schematic side view thereof, and FIGS. 10 and 11 are charts showing the effects of the present invention. 1...Main wing, 4...Pylon, 5...
... Leading edge flap, 11 ... Small wing plate.

Claims (1)

[Claims] 1. In an aircraft having a pylon protruding obliquely from the lower part of the main wing, a leading edge high lift device is provided at the leading edge of the main wing, and the leading edge high lift device is a part that interferes with the pylon. The notch is provided with a small wing plate extending along the leading edge of the main wing, and the small wing plate is located between a protruding position and a storage position so as to fill at least a part of the notch. A high-lift device for an aircraft, characterized in that it is movably arranged. 2. The high-lift device for an aircraft according to item 1, wherein the small wing plate can be stored in the front part of the main wing. 3. The high-lift device for an aircraft according to item 2 above, wherein a rail is provided on the main wing to serve as a guide for retracting the small wing plate into the main wing. 4. The high-lift device for an aircraft according to item 1, wherein the small wing plate is housed in a pylon. 5. The high-lift device for an aircraft according to item 4, wherein the pylon is provided with a recessed portion on its side surface to accommodate the small wing plate. 6. The high-lift device for an aircraft according to item 4, wherein the wing plate is supported by the pylon by a hinge, and is rotated about the hinge to be housed in the pylon. 7. The high-lift device for an aircraft according to item 1, wherein the small wing plate is arranged such that a slot is formed between the wing plate and the leading edge of the main wing in the lowered position.