Pressure-actuated closing device for regulating the air flow of an engine fan
Publication Date: 2015-Mar-26
The IP.com Prior Art Database
The invention relates to a closing device for regulating the air flow in the engine fan compartment of an aircraft. The closing device comprises a bi-stable plate able to maintain two distinct states and to snap between these stable states if a sufficient pressure or a punctual force is applied. The closing device further comprises a return device used to actuate the bi-stable plate from the closed state to the open state. The return device can be a single extension spring attached between the bi-stable plate and a wall of the air inlet or an elastic layer attached to one or both sides of the bi-stable plate. The invention described therein is a simple and passive closing device aiming at regulating the airflow in an air inlet. This regulation limits the drag impact to the strict minimum, while the weight and the complexity of the system remains low.
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PRESSURE-ACTUATED CLOSING DEVICE FOR REGULATING THE AIR FLOW OF AN ENGINE FAN
This disclosure relates to a closing device for regulating the air flow in the engine fan compartment of an aircraft.
It is known from WO2012/049500: a closing device for ail inlets comprising a multi- stable member that can be deformed between a first and a second position within the air inlet. In an embodiment of this invention, an actuator is provided to cause the multi-stable member to move to and from the first and the second position, thus opening and closing the air inlet.
However this closing device requires a control system and a power supply system, both systems adding complexity and weight to the air inlet.
It is proposed a closing device which can solve the problems associated with the prior-art.
Description of the invention:
A closing device according to the invention comprises a bi-stable plate and a passive actuation system to regulate the position of said bi-stable plate.
The bi-stable plate maintains two stiff distinct states but can snap between these stable states if a sufficient pressure or punctual force is applied. The two stable states correspond to an open and a close configuration, which can be used to regulate the air flow by closing partially the air inlet as can be seen in figure 1. The bi- stable plate is designed so that the high dynamic pressure corresponding to high speed flight is sufficient to actuate the bi-stable plate from the open to the closed state.
In flight, depending on the speed of the aircraft, the dynamic pressure around the aircraft varies. At low-speed flight, there is low-dynamic pressure and at high-speed flight, high-dynamic pressure. The difference between those pressures is used in an embodiment of the invention described herein.
Figure 1: Open and closed configuration of the bi-stable plate.
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In a variant, the bi-stable plate is associated with a return device such as a spring or a rubber layer attached to the pl...