JPH04317892A - Helicopter rotor blade - Google Patents

Abstract

PURPOSE:To suppress noise and vibration by optionally changing the lower camber angle of a helicopter rotor blade during flight to avoid or reduce the interference of the top end vortex of the rotor blade with the following rotor blade. CONSTITUTION:A rotatable shaft disposed in the chord direction on a rotor blade body, a top end wing part 4 whose wing root part is mounted on the rotatable shaft, and a driving device 5 for rotating the rotatable shaft are provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helicopter rotor blade whose anhedral angle can be adjusted during flight.

0002

[Prior Art] Conventionally, some helicopter rotor blades have tip blades inclined downward with respect to the surface of the rotor blade to form an anhedral angle. The rotor blade was fixedly attached to the main body of the rotor blade, and the anhedral angle could not be set arbitrarily during flight.

0003

[Problems to be Solved by the Invention] Conventional helicopter rotor blades have the following problems.

(1) One of the sources of vibration and noise in helicopters is aerodynamic interference between rotor blades. Aerodynamic vortices are always generated from the tip of a rotating helicopter rotor blade and released into the air. This vortex eventually collides with the trailing rotor blades that catch up from behind, causing the intense noise and vibrations characteristic of helicopters.

(2) As one means to avoid this, a technique has been devised to angle the tip end portion of the rotor blade downward (anhedral angle). Such rotor blades quickly push the aerodynamic vortices generated from the tips of the blades downward from the rotor rotating surface to avoid interference with trailing blades, or to reduce the impact intensity if interference occurs. It can be relaxed.

(3) However, in conventional rotor blades with such an anhedral angle, the tip wing portion is fixed to the blade body with a screw or the like, as described above, and therefore, It is not possible to make fine adjustments to the diversion angle.

(4) The degree of interference between the tip vortex and the trailing blade is significantly influenced by the speed and motion of the helicopter, with the greatest vortex interference generally occurring during landing and descent. In other words, with the conventional rotor blade having the fixed tip wing section, it was not possible to set an appropriate diversion angle depending on the flight condition.

The present invention seeks to provide a helicopter rotor blade that can solve the above problems.

[0009]

[Means for Solving the Problems] The helicopter rotor blade of the present invention includes a rotatable shaft disposed at the tip of the rotor blade body in the chord direction of the rotor blade body; The blade includes a tip blade portion to which the blade root portion is attached, and a drive device for rotating the rotatable shaft.

0010

[Operation] In the present invention, when the drive device rotates the rotatable axis in the chord direction at the tip of the rotor blade body, the tip wing portion rotates around the rotatable axis along with the coaxial rotation. , the anhedral angle of the helicopter rotor blades is adjusted. As a result, the anhedral angle of the helicopter rotor blade is set suitable for flight conditions such as the speed and motion of the helicopter, and interference between the tip vortex and the trailing blade can be avoided or alleviated.

[0011]

[Embodiment] An embodiment of the present invention will be explained with reference to FIGS. 1 and 2. Figure 1 shows the helicopter rotor according to the same embodiment.
A helicopter with blades is shown, and an anhedral control processor (computer) 2 is mounted in a cabin or cockpit 1 of the helicopter 20. This anhedral angle control processor 2 is connected to an automatic flight control device (not shown), etc., and calculates flight specifications necessary for anhedral angle calculation, such as helicopter flight speed and flight altitude, as well as vibration and noise control in real time. Levels are now available. The anhedral angle control processor 2 is provided with a switching mechanism between an anhedral angle automatic calculation mode and an anhedral angle mode.

The anhedral angle control processor 2 is connected to a tip blade driving device 5 provided in the tip of the rotor blade body 3.
A signal giving the required diversion angle is output electrically or optically.

FIG. 2 shows the tip wing section and its driving device. The tip blade driving device 5 includes an anhedral angle controller 6, a tip blade rotating device (for example, a small electric motor) 7 to which electric power is supplied from the anhedral angle controller 6, and a rotating device 7 for rotating the rotating device 7. A gear 8 attached to the shaft 7', a rotating shaft 9, a gear 10 attached to the rotating shaft 9 and meshing with the gear 8,
It consists of a rotating shaft mounting bracket 11, and is disposed at the tip of the rotor body 3 of the rotor blade and in the tip wing section to be described later. The rotation shaft 9 is arranged at the tip of the rotor blade body 3 in the chord direction of the rotor blade body 3,
Both ends thereof are rotatably attached to a pair of rotating shaft attachment fittings 11 attached to the rotor blade body 3. Further, a blade root portion of the tip blade portion 4 is attached to this rotating shaft 9.

In this embodiment, in response to a command from the anhedral angle control processor 2, power is supplied from the anhedral angle controller 6 to the tip blade rotation device 7, and the tip blade rotation device 7 performs the following operations. gear 8
The gear 10 is rotated via the rotary shaft 9, and the rotating shaft 9 is rotated. As a result, the tip wing portion 4 is rotated in a direction perpendicular to the plane of the rotor blade body 3 via the rotation shaft 9, and is mechanically fixed when the desired anhedral angle is obtained.

As described above, when the helicopter 20 is in flight, the lower half angle of the helicopter rotor blade can be adjusted automatically or by the pilot's operation. As a result, it is possible to set an appropriate lower half angle of the helicopter rotor blade depending on flight conditions such as the speed and motion of the helicopter 20, and to avoid or reduce interference between the tip vortex of the rotor blade and the trailing blade. do,
Helicopter noise and vibration can be suppressed.

Further, when the helicopter 20 flies in an urban area, the anhedral angle of the rotor blade is increased to control noise, and when the helicopter 20 flies in a non-urban area, the anhedral angle is decreased. The rotor disk area can also be made larger to allow flight to improve performance.

[0017]

[Effects of the Invention] The present invention can achieve the following effects.

(1) Since the anhedral angle of the helicopter rotor blade can be arbitrarily controlled during flight, it is possible to control noise and vibration peculiar to helicopters over the entire flight range.

(2) When a helicopter flies in an urban area, the anhedral angle of the rotor blade is increased to suppress noise; on the other hand, when the helicopter flies in a non-urban area, the anhedral angle is increased. By making the rotor disk smaller, flight performance can be improved by increasing the area of the rotor disk, and as a result, the scope of operation of the helicopter can be expanded.

(3) Since the size of the anhedral angle formed by the tip wing of the helicopter rotor blade can be easily changed, various flight tests for researching the shape of the helicopter blade wing can be easily performed. As a result, it is expected that the helicopter research and development period will be shortened.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a helicopter equipped with rotor blades according to an embodiment of the present invention.

FIG. 2 is an internal view showing the tip wing section and its driving device in the same embodiment.

[Explanation of symbols]

1 Helicopter cabin or cockpit 2
Anhedral angle control processor 3 Rotor blade body 4 Tip wing section 5 Tip wing drive device 6 Anhedral angle controller 7 Tip wing rotation device 8 Gear 9 Rotating shaft 10 Gear 11 Rotating shaft mounting bracket 20 Helicopter

Claims (1)

[Claims] 1. A rotatable shaft disposed at a tip of a rotor blade body in the chord direction of the rotor blade body, a tip blade portion having a blade root portion attached to the rotatable shaft, and a rotating shaft. Helicopter rotor blade, characterized in that it is equipped with a drive device for rotating a possible axis.