JPH05124589A - Blade of helicopter - Google Patents

Abstract

PURPOSE:To prevent reduction in the pressure of a rear end part of a blade vane end, and to prevent generation of a vane thickness noise component of the wind-cutting sound of the blade by providing a tubular hole penetrating the blade in the spanning direction, and by opening the end part of the hole at a specified position on the blade vane surface. CONSTITUTION:A tubular hole 6 penetrating a blade 1 is provided on the blade 1 of a helicopter in the spanning direction, and one end part of the hole 6 is opened on the vane surface of the upper surface of the blade 1 in the vicinity of a part where the blade is mounted, and an air intake port 4 is thus formed, while the other end of the hole 6 is opened on the vane surface of the upper surface of the blade 1 of a rear end part 3 of the blade vane end part, and an air ejection nozzle 5 is thus formed. The air taken in from the air intake port 4 is continuously blown out of the air ejection nozzle 5 at the time of the rotation of the blade 1, so as to prevent reduction in the pressure of the rear end part of the vane end part of the blade 1, and the generation of a vane thickness noise component of the wind-cutting sound of the blade 1 is thus suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helicopter blade capable of reducing wind noise.

[0002]

2. Description of the Related Art In a conventional helicopter blade 1 designed to reduce noise, as shown in FIG. 4, a positive pressure pulse generated at a front edge portion 02 of a helicopter blade 01 and a trailing edge portion 03 are generated. In order to reduce the magnitude of the negative pressure pulse that is generated and reduce the generation interval, it has been performed to reduce the blade thickness 07 and increase the blade cord length 05.

[0003]

In the blade of the conventional noise-reducing helicopter, in order to reduce the blade thickness and increase the blade cord length, the blade strength is reduced, and the aerodynamic characteristics such as the lift distribution of the blade are reduced. There were problems such as deterioration and increased air resistance during forward flight.

The present invention is intended to provide a helicopter blade capable of solving the above problems.

[0005]

A blade of a helicopter according to the present invention is provided with a hole penetrating in the blade in a span direction, and an end portion of the hole is provided near a blade attachment portion and a trailing edge portion of a blade tip portion. It is characterized in that it is opened on the blade surface.

[0006]

According to the present invention, the air in the tubular hole penetrating the rotating blade in the span direction is jetted by centrifugal force from the opening at the end of the hole at the trailing edge of the blade blade end, and Air is taken into the hole through an opening at the end of the hole near the attachment of the blade. As a result, air is continuously ejected from the opening at the end of the hole at the trailing edge of the blade blade, and the blade thickness noise component of the blade wind noise can be suppressed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In this embodiment, a tubular hole 6 that penetrates the blade 1 of the helicopter is provided in the span direction of the blade 1,
One end of the hole 6 is opened on the blade surface on the upper surface of the blade near the blade mounting portion to form the air intake 4, and the other end of the hole 6 is the blade surface on the upper surface of the blade at the trailing edge portion 3 of the blade blade end. The air jet opening 5 is formed by opening it.

In this embodiment constructed as described above, when the blade 1 of the helicopter rotates, a centrifugal force acts on the air in the hole 6. As a result, the air in the hole 6 is ejected from the air ejection port 5 of the trailing edge portion 3 of the blade tip portion, and the air is taken into the hole 6 from the air intake port 4 near the blade mounting portion.

Therefore, when the helicopter blade 1 is rotated, air is continuously ejected from the air ejection port 5 to prevent the pressure drop at the trailing edge portion of the blade end portion of the blade 1 and thereby to prevent the blade from falling. It is possible to suppress the generation of the blade thickness noise component of the wind noise.

[0010]

The blade of the helicopter of the present invention is provided with a tubular hole penetrating through the blade in the span direction, and the end portion of the hole has a blade blade surface near the blade mounting portion and at the trailing edge portion of the blade blade end portion. The air in the hole of the rotating blade is continuously blown out from the opening of the hole at the trailing edge of the blade tip of the blade due to centrifugal force. As a result, the pressure at the trailing edge of the blade tip can be prevented from decreasing, and thus the blade thickness noise component of the wind noise of the blade can be suppressed.

[Brief description of drawings]

FIG. 1 is an external view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along the line BB of FIG.

FIG. 4 is an external view of a blade of a conventional helicopter.

[Explanation of symbols]

 1 Helicopter blade 2 Leading edge 3 Trailing edge 4 Air intake 5 Air jet 6 Hole

Claims (1)

[Claims] 1. A tubular hole penetrating the inside of the blade in a span direction, wherein the end of the hole is opened to the blade blade surface near the blade attachment portion and the trailing edge of the blade blade tip. And a helicopter blade.