Patent ID: 7854447
Filing Date: 2010-12-21
Classification: B60R

Abstract:
1. An instrument panel assembly comprising: an airbag; an instrument panel including a door portion having an undersurface facing the airbag; an outer frangible portion of the instrument panel extending about the door portion and configured to rupture and cause the door portion to separate from the instrument panel , upon deployment of the airbag; a central frangible portion extending generally centrally along the instrument panel door portion and configured to cause the door portion to rupture at the central frangible portion after separating from the instrument panel so that the door portion bulges outwardly to protrude further outwardly at the central frangible portion than at the earlier ruptured outer frangible portion before rupture of the central frangible portion during airbag deployment; a door frame under the instrument panel; a stationary door frame member of the door frame connected to the instrument panel adjacent the door portion thereof; a moveable door frame member connected to the stationary door frame member for being shifted relative thereto upon airbag deployment; adjacent depending leg portions of the stationary and movable door frame members with the leg portions of the moveable door frame member shifting relative to the adjacent leg portions of the stationary door frame member upon airbag deployment; a pair of backing plate portions of the moveable door frame member extending transverse to the moveable door frame member leg portions, and being attached to the undersurface of the door portion to extend therealong with the central frangible portion extending between the backing plate portions; a hinge joint between each backing plate portion and corresponding leg portion of the moveable frame member so that the backing plate portions stay hingedly connected to the leg portions during airbag deployment; and rupturable grooves of the movable door frame provided along each hinge joint to partially separate each backing plate portion from the corresponding leg portion when the backing plate portion starts to open, the rupturable grooves each being configured as an elongate channel preformed in the respective hinge joints prior to airbag deployment so that the grooves do not extend completely through the hinge joints and the hinge joints are thinner along the grooves; wherein the backing plate portions and the stationary door frame member are fixed to the instrument panel by vibration welding; the rupturable grooves extend over a predetermined length between one end and the other end of each hinge joint in the extending direction thereof, and one end of each rupturable groove is aligned with a rim of the movable door frame member; the sum of the length of the rupturable grooves in each hinge joint is less than the full length of the backing plate portion in the extending direction of the hinge joint; the channel configuration of the rupturable grooves providing the grooves with a strength lower than that of the central frangible portion to cause the grooves to rupture during airbag deployment prior to rupture of the central frangible portion when the backing plate portions and overlying door portions are pushed by the inflating airbag to allow the backing plate portions and overlying door portions to have a flat, attached configuration at the ruptured rupturable grooves; and each backing plate portion is connected to the corresponding leg portion of the movable door frame member via each hinge joint over the entire length of the backing plate portion until the rupturable grooves rupture.