Patent ID: 8512111

Claim:
A vehicle cowl box structure comprising: an air inlet arranged to receive outside air; an air outlet arranged to convey the outside air to a vehicle HVAC system; an air passageway extending between the air inlet and the air outlet to convey the outside air from the air inlet to the air outlet, the air passageway having a first side wall and a second side wall opposite the first side wall; and a flow restriction device disposed in the air passageway at a point between the air inlet and the air outlet, the flow restriction device being configured and arranged to automatically decrease airflow from the air inlet to the air outlet as the airflow through the air inlet increases, the flow restriction device including at least one moveable flap pivotally mounted about a pivot axis midway between the first and second side walls, the flap having a first end and a second end, the flap moving from a first position towards a second position as the airflow through the air inlet increases such that an amount of the airflow to the air outlet decreases as the flap moves farther from the first position towards the second position, the flap having an airfoil-shape with upper and lower surfaces shaped such that the airflow causes the flap to move from the first position towards the second position as the airflow increases such that a first portion of the airflow passes over the flap and a second portion of the airflow passes under the flap, the first position corresponding to the flap being positioned with little or no blockage of the air passageway and the second position corresponding to the flap being positioned for maximum blockage of the air passageway, the second end moving away from the first side wall and toward the second side wall during movement from the first position to the second position, the second end being spaced apart from the second side wall with the flap in the second position such that the second end is always spaced apart from the second side wall.