Active bolster with active vent for load management

Abstract

An active bolster has a plastic-molded, expandable front wall and a plastic-molded back wall joined around a substantially sealed perimeter with the front wall to form an inflatable bladder. The back wall includes at least one active vent and at least one substantially circumferential pleated baffle. An inflator couples an inflation gas into the inflatable bladder in response to a crash event of the vehicle. The active vent comprises a window opening in the back wall and an integrally-molded flap juxtaposed to the window opening. The flap has an undeflected position corresponding to a first flow coefficient and a deflected position corresponding to a second, nonzero flow coefficient that is less than the first flow coefficient. The flap moves from the undeflected position to the deflected position when a pressure in the inflatable bladder resulting from a passenger impact is greater than a predetermined pressure.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]Not Applicable.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH Not Applicable.BACKGROUND OF THE INVENTION[0002]The present invention relates in general to active bolsters for occupant crash protection in automotive vehicles, and, more specifically, to an active bolster with an inflatable bladder formed by plastic wall panels that is vented to manage a deflation rate during impact according to the energy at which a passenger impacts the bolster.[0003]An active bolster is a vehicle occupant protection device with a gas-inflatable bladder to absorb impacts and reduce trauma to occupants during a crash. As opposed to deployable air bag cushions made of various fabrics that emerge from behind various openings upon inflation, active bolsters use the interior trim surface itself to expand at the beginning of a crash event for absorbing the impact and dissipating energy through the action of an inflation gas. U.S. Pat. No. 8,205,909, issued Jun....

AI Technical Summary

Problems solved by technology

Otherwise, noticeable deformation of the interior trim component incorporating the active bolster may occur during temperature extremes since the panel materials are relatively flexible.

It has been found that an active vent that assumes a higher flow coefficient in response to a higher pressure may lead to insufficient energy management in some circumstances, such as a relatively hard impact (e.g., a relatively heavy passenger moving at a moderate velocity or a smaller passenger moving at a relatively high velocity).

In this particular situation, an undesirably fast deflation of the bladder may result in insufficient initial deceleration of the impacting body which may then be followed by a bottoming out of the bolster (and a sudden deceleration of the impacting body) once the bolster has completely collapsed.

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