One-way multiple chambers and cushions airbag

A one-way multiple cushions and chambers vehicle airbag assembly includes an airbag body having a primary airbag chamber and a secondary airbag chamber. At least one one-way vent valve provides a gas interconnection passage between the primary airbag chamber and the secondary airbag chamber.

INTRODUCTION

The present disclosure relates to vehicle airbags.

Current vehicle designs provide airbags in multiple locations to provide additional protection of vehicle occupants during collision events. An airbag is a vehicle occupant-restraint system using a bag designed to inflate quickly, then deflate. Airbags commonly consist of an airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. The airbag provides an energy-absorbing surface between a vehicle occupant and objects including a steering wheel, an instrument panel, a body pillar, a headliner, and a windshield. Modern vehicles may contain up to 10 airbag modules in various configurations, including: driver, passenger, side-curtain, seat-mounted, door-mounted, B-pillar and C-pillar mounted side-impact, knee bolster, inflatable seat belt, and pedestrian airbag modules. During a collision event, vehicle sensors provide information to an airbag electronic controller unit (ECU). Firing circuits controlled by the ECU deploy one or more airbag modules within the vehicle. Airbags act as a supplemental restraint system to the vehicle's seat-belt systems, and airbag module deployments are commonly triggered through a pyrotechnic process.

While current vehicle airbag assemblies achieve their intended purpose, there is a need for a new and improved vehicle airbag assembly.

SUMMARY

According to several aspects, a one-way multiple cushions and chambers vehicle airbag assembly includes an airbag body having a primary airbag chamber and a secondary airbag chamber. At least one one-way vent valve provides a gas interconnection passage between the primary airbag chamber and the secondary airbag chamber.

In another aspect of the present disclosure, a connecting wall is positioned between and separates the primary airbag chamber and the secondary airbag chamber. The connecting wall defines a substantially impermeable barrier to gas transfer between the secondary airbag chamber and the primary airbag chamber when the airbag is inflated during an airbag deployment event.

In another aspect of the present disclosure, the at least one one-way vent valve extends through the connecting wall.

In another aspect of the present disclosure, when fully inflated with a gas during the airbag deployment event the secondary airbag chamber defines a supplementary cushion volume bounded between the connecting wall and an outer occupant facing wall.

In another aspect of the present disclosure, the at least one one-way vent valve penetrates the connecting wall allowing a first portion of a gas filling the airbag body during the deployment event to be directed from the primary airbag chamber into the secondary airbag chamber.

In another aspect of the present disclosure, the at least one one-way vent valve penetrates the connecting wall allowing a first portion of a gas filling the airbag body during the deployment event to be directed from the secondary airbag chamber into the primary airbag chamber.

In another aspect of the present disclosure, the at least one one-way valve includes a first one-way vent valve and a second one-way vent valve individually having a stitched border providing stiffness to maintain an opening port to allow gas flow through the first one-way vent valve and the second one-way vent valve during deflation of the airbag body.

In another aspect of the present disclosure, the primary airbag chamber includes a first chamber portion and a second chamber portion in open fluid communication.

In another aspect of the present disclosure, a tether is positioned between the first chamber portion and the second chamber portion, and the first chamber portion and the second chamber portion together define the primary airbag chamber.

In another aspect of the present disclosure, a vent hole is positioned in the primary airbag chamber to vent the primary airbag chamber to atmosphere following an airbag deployment event.

According to several aspects, a one-way multiple cushions and chambers vehicle airbag assembly includes an airbag body having a primary airbag chamber and a secondary airbag chamber. The airbag body is connected to a source of a gas used to inflate the airbag body during an airbag deployment event. A connecting wall is positioned between the primary airbag chamber and the secondary airbag chamber. First and second one-way vent valves penetrate the connecting wall and individually provide a gas interconnection passage between the primary airbag chamber and the secondary airbag chamber allowing a primary flow of the gas from one of the primary airbag chamber and the secondary airbag chamber into the other one of the primary airbag chamber and the secondary airbag chamber during the airbag deployment event.

In another aspect of the present disclosure, the connecting wall defines a substantially impermeable barrier to gas transfer between the secondary airbag chamber and the primary airbag chamber.

In another aspect of the present disclosure, the first one-way vent valve and the second one-way vent valve do not preclude but restrict a reverse flow of the gas back into the primary airbag chamber, allowing the secondary airbag chamber to deflate after the airbag deployment event slower than a deflation rate of the primary airbag chamber.

In another aspect of the present disclosure, the connecting wall defines an outer face of the primary airbag chamber.

In another aspect of the present disclosure, the connecting wall defines an outer face of the secondary airbag chamber.

In another aspect of the present disclosure, the first and second one-way vent valves individually include: a first edge wall having a first wall thickness; a second edge wall oppositely positioned with respect to the first edge wall having a second wall thickness greater than the first wall thickness to permit the first edge wall to collapse more easily than the second edge wall; and a first height of the first edge wall being shorter than a second height of the second edge wall edge to control a collapse direction of the first and second one-way vent valves.

In another aspect of the present disclosure, the first and second one-way vent valves individually include: opposing wall edges having an equal thickness; and an opening port having a stitched border providing stiffness to maintain the opening port open during collapse of the first and second one-way vent valves when the airbag body deflates.

According to several aspects, a method for inflating multiple cushions and chambers of a vehicle airbag assembly, comprises: positioning a connecting wall between a primary airbag chamber and a secondary airbag chamber of an airbag body; directing one of the primary airbag chamber and the secondary airbag chamber toward an occupant of a vehicle during inflation of the airbag body with a gas during an airbag deployment event; and extending first and second one-way vent valves through the connecting wall to individually provide a gas interconnection passage between the primary airbag chamber and the secondary airbag chamber allowing a primary flow of the gas from one of the primary airbag chamber and the secondary airbag chamber into the other one of the primary airbag chamber and the secondary airbag chamber during the airbag deployment event.

In another aspect of the present disclosure, the method further includes: configuring the airbag body having the secondary airbag chamber directed toward the occupant of the vehicle during inflation of the airbag body to use the secondary airbag chamber as a cushion for a head of the occupant; and selectively arranging the primary flow of the gas from the primary airbag chamber into the secondary airbag chamber to permit the secondary chamber to deflate slower than the primary airbag chamber to maintain at least a portion of the cushion to remain between the head of the occupant an structure of the vehicle.

In another aspect of the present disclosure, the method further includes: configuring the airbag body having the primary airbag chamber directed toward the occupant of the vehicle during inflation of the airbag body to allow the primary airbag chamber to be first contacted by a head of the occupant; and selectively arranging the primary flow of the gas from the secondary airbag chamber into the primary airbag chamber having the secondary airbag chamber deflating slower than the primary airbag chamber to maintain at least a portion of the secondary airbag chamber to remain between the head of the occupant and a structure of the vehicle.

DETAILED DESCRIPTION

Referring toFIG.1, a known airbag assembly10includes an airbag body12having a first portion14and a second portion16which together define a single airbag chamber17having a tether18centrally disposed through the airbag chamber17. The first portion14and the second portion16are in open fluid communication such that the tether18does not act as a fluid boundary between the first portion14and the second portion16, but acts to internally structurally stiffen the airbag body12when the airbag body12is fully inflated as shown. A gas fill inlet20opens into the airbag body12supplying a flow of a gas22under pressure used to fill the airbag body12as is known. The gas22is supplied from a gas generator such as a pyrotechnic device24located adjacent to and outside of the airbag body12.

Airbag assembly deployment is commonly controlled by an airbag electronic controller unit (ECU), which incorporates a collision type, a collision angle, and a severity of impact to determine when and if to deploy the airbag assembly. An airbag ECU's crash algorithm determines if the crash event meets the criteria for deployment and triggers various firing circuits to deploy one or more airbag assemblies, Airbag assembly deployments are commonly triggered through the pyrotechnic device24which releases the gas22into the airbag body12. The airbag body12deflates following a collision event by allowing the gas22to flow outwardly from the airbag chamber17of the airbag body12through a vent hole26. The vent hole26is sized to allow deflation of the airbag body12.

Referring toFIG.2and again toFIG.1, the known airbag assembly10is shown positioned within a vehicle28such as an automobile vehicle and following a collision event sufficient to trigger airbag deployment. An occupant torso30of a vehicle occupant is restrained by seatbelts to a vehicle seat32allowing rotation of the occupant torso30and an occupant head34about an arc of rotation36during the collision event. A forward-facing surface38of the occupant head34contacts an outer surface40of the airbag body12which locally compresses the airbag chamber17at a chamber region42of the airbag body12. Under certain conditions of occupant acceleration, the airbag chamber17expands outwardly allowing total or near-total compression of the chamber region42permitting the occupant head34to contact for example a vehicle object44such as a glove box shown, a steering wheel, or other vehicle structure, with the material of the outer surface40positioned between the occupant head34and the object44.

Referring toFIG.3Aand again toFIGS.1and2, according to the present disclosure a one-way multiple cushions and chambers airbag assembly45may include the gas generator such as the pyrotechnic device24′ fixed to and in communication with a connecting chamber46. The connecting chamber46may be fixed to a mounting connector47which couples the connecting chamber46to a gas fill inlet48.

Referring toFIG.3Band again toFIGS.1,2and3A, the one-way multiple cushions and chambers airbag assembly45is provided to mitigate against an airbag single chamber collapse possible with the airbag assembly10described in reference toFIGS.1and2. It is noted components of the one-way multiple cushions and chambers airbag assembly45having the same or similar components as the airbag assembly10are denoted with an apostrophe symbol. The one-way multiple cushions and chambers airbag assembly45includes an airbag body49having a first chamber portion50and a second chamber portion52. The first chamber portion50and the second chamber portion52together define a first or primary airbag chamber54. A tether56is substantially centrally positioned within the airbag body49and may be fixed at a connecting end58to the gas fill inlet. The first chamber portion50and the second chamber portion52are in fluid communication as the tether56acts to internally structurally stiffen the airbag body12when the airbag body12is fully inflated as shown and provides substantially no separation of the gas in the first chamber portion50and the second chamber portion52when the airbag body49is fully inflated as shown.

The gas fill inlet48opens into the airbag body49supplying a flow of a gas60under pressure used to fill the airbag body49as is known. The gas60is supplied from a gas generator such as a pyrotechnic device24′ located adjacent to and outside of the airbag body49. Airbag assembly deployments are commonly triggered through the pyrotechnic device24′ which releases the gas60into the airbag body49. The airbag body49deflates following a collision event by allowing the gas60to flow outwardly from the primary airbag chamber54through a vent hole62. The vent hole62is sized to allow deflation of the airbag body49to atmosphere following full deployment of the airbag body49following the airbag deployment event.

In addition to the primary airbag chamber54, the airbag body49further includes a secondary airbag chamber64. A connecting wall66of the secondary airbag chamber64creates an outer face68of the primary airbag chamber54with the connecting wall66defining a substantially impermeable barrier to gas transfer between the secondary airbag chamber64and the primary airbag chamber54with the exception of the one-way vent valves noted below. When fully inflated the secondary airbag chamber64defines a supplementary cushion volume70bounded between the connecting wall66and an outer occupant facing wall72.

The secondary airbag chamber64is inflated in conjunction with and substantially simultaneously during filling the primary airbag chamber54. As the gas60enters the primary airbag chamber54the gas60flows toward the outer face68of the airbag body49and enters a first one-way vent valve74which penetrates the connecting wall66allowing a first portion of the gas60as a gas flow76into the secondary airbag chamber64. According to several aspects a second one-way vent valve78also penetrates the outer face68allowing a second portion of the gas60as a gas flow80to enter the secondary airbag chamber64. The first one-way vent valve74and the second one-way vent valve78individually provide a gas interconnection passage between the primary airbag chamber54and the secondary airbag chamber64. According to several embodiments additional one-way valves may also be used as determined by the airbag body49volume and fill time requirements. The first one-way vent valve74and the second one-way vent valve78do not preclude but restrict reverse flow of the gas60back into the primary airbag chamber54, allowing the secondary airbag chamber64to slowly empty after deployment of the one-way multiple cushions and chambers airbag assembly45as discussed in reference toFIGS.7and9below.

Referring toFIG.4and again toFIGS.2and3B, during an airbag deployment event the occupant torso30′ of the vehicle occupant is restrained by seatbelts to the vehicle seat32′ allowing rotation of the occupant torso30′ and the occupant head34′ about the arc of rotation36′ during the collision event. The forward-facing surface38′ of the occupant head34′ initially contacts the outer occupant facing wall72of the secondary airbag chamber64which locally partially compresses the secondary airbag chamber64. Under certain conditions of occupant acceleration the primary airbag chamber54expands outwardly allowing total or near-total compression of the chamber region42shown in reference toFIG.2. Because the gas60is temporarily trapped in the secondary airbag chamber64by the first one-way vent valve74and the second one-way vent valve78, the secondary airbag chamber64does not collapse and continues to support the occupant head34′ in a chamber region82of the secondary airbag chamber64such that the occupant head34′ is precluded from contacting the vehicle object44′. The chamber region82is gas filled and provides a clearance gap84between the forward-facing surface38′ of the occupant head34′ and the object44′.

Referring toFIG.5and again toFIGS.3B and4, a graph86presents an occupant acceleration88(g) compared to a time 90 (msec) during an exemplary airbag deployment event. A base curve92represents an occupant displacement over time for the airbag assembly45having a maximum acceleration94occurring at approximately 90 msec after initiation of the event. An acceleration region96presents subsequent accelerations of the occupant head34′ less than the maximum acceleration94between approximately 110 msec and 125 msec as the occupant head34′ compresses the single airbag chamber17. A region-of-interest (ROI) curve98presents exemplary occupant head34′ acceleration over time resisted by the one-way multiple cushions and chambers airbag assembly45of the present disclosure. The ROI curve98identifies the occupant head34′ has a peak acceleration100less than the maximum acceleration94. The portion of the ROI curve98proximate to the acceleration region96also presents substantially reduced occupant head34′ acceleration levels, having a secondary peak acceleration102of approximately 33 g compared to a secondary maximum acceleration104of approximately 54 g when the airbag assembly10is employed to resist occupant acceleration.

Referring toFIG.6and again toFIG.3B, the first one-way vent valve74is shown in greater detail in a fully extended position during inflation of the one-way multiple cushions and chambers airbag assembly45. The first one-way vent valve74penetrates the connecting wall66allowing the first portion of the gas60as the gas flow76to flow from the primary airbag chamber54into the secondary airbag chamber64. The second one-way vent valve78shown in reference toFIG.3Bis similar to the first one-way vent valve74and is therefore not further shown or discussed herein. A stitched border106provides stiffness to maintain an opening port108defining a gas interconnection passage which allows gas flow through the first one-way vent valve74. A first edge wall110of the first one-way vent valve74has a first wall thickness112. A second edge wall114the first one-way vent valve74oppositely positioned with respect to the first edge wall110has a second wall thickness116greater than the first wall thickness112to permit the first edge wall110to collapse more easily than the second edge wall114. A first height118of the first edge wall110is shorter than a second height120of the second edge wall114to control a collapse direction of the first one-way vent valve74.

The gas interconnection passage between the primary airbag chamber54and the secondary airbag chamber64allows the gas flow76and the primary flow80of the gas60from the primary airbag chamber54into the secondary airbag chamber64during the airbag deployment event. The first one-way vent valve74and the second one-way vent valve78do not preclude but restrict a reverse flow of the gas60back into the primary airbag chamber54, allowing the secondary airbag chamber64to empty after the airbag deployment event slower than a deflation rate of the primary airbag chamber54, thereby maintaining the cushion of the secondary airbag chamber64longer during the deployment event.

Referring toFIG.7and again toFIG.6, the first one-way vent valve74is shown during venting of the secondary airbag chamber64back into the primary airbag chamber54following airbag deployment. Because the second wall thickness116is greater than the first wall thickness112the first one-way vent valve74collapses initially in a direction122opposite to the second edge wall114and thereafter in a direction124toward the connecting wall66. As noted above, the stitched border106provides stiffness to maintain the opening port108open during vent valve collapse. A restricted gas flow is thereby allowed in a gas flow direction126through the first one-way vent valve74from the secondary airbag chamber64back into the primary airbag chamber54.

Referring toFIG.8and again toFIGS.6and7, according to further aspects, a third one-way vent valve128may be used in place of either or both of the first one-way vent valve74and the second one-way vent valve78. The third one-way vent valve128is shown during venting of the secondary airbag chamber64back into the primary airbag chamber54following airbag deployment. A third edge wall130and an opposed fourth edge wall132have an equal or common third wall thickness134.

Referring toFIG.9and again toFIG.8, due to the common third wall thickness134of the third edge wall130and the fourth edge wall132, the third one-way vent valve128collapses substantially in the direction124′ toward the connecting wall66. As noted above, the stitched border106′ provides stiffness to maintain the opening port108′ open during vent valve collapse. A restricted gas flow is thereby allowed in a gas flow direction136through the third one-way vent valve128from the secondary airbag chamber64back into the primary airbag chamber54which may take a less circuitous route than the flow direction126discussed in reference toFIG.7.

Referring toFIG.10and again toFIGS.3B and4, an occupant142representing a 5th percentile occupant by weight is shown at approximately 50 msec into an airbag deployment event. An occupant head144of the occupant142initially contacts the outer occupant facing wall72of the secondary airbag chamber64. At this time the primary airbag chamber54is substantially unchanged from the fully inflated position shown inFIG.3B.

Referring toFIG.11and again toFIGS.3B,4and10, the occupant142is shown at approximately 80 msec into the airbag deployment event. The occupant head144has partially collapsed the secondary airbag chamber64approximately retaining the chamber region82of the secondary airbag chamber64. The primary airbag chamber54has partially collapsed but the occupant head144is entirely clear of the object44′.

Referring toFIG.12and again toFIGS.3B,4and10through11, an occupant146representing a 50thpercentile occupant by weight is shown at approximately 50 msec into an airbag deployment event. A head148of the occupant146initially contacts the outer occupant facing wall72of the secondary airbag chamber64. The occupant head148has partially collapsed the secondary airbag chamber64approximately retaining the chamber region82of the secondary airbag chamber64. The primary airbag chamber54has partially collapsed but the occupant head148is entirely clear of the object44′.

Referring toFIG.13and again toFIGS.3B,4and10through12, the occupant146is shown at approximately 80 msec into the airbag deployment event. The occupant head148has partially collapsed the secondary airbag chamber64retaining the chamber region82of the secondary airbag chamber64. The primary airbag chamber54has partially collapsed but the occupant head148is spaced from the object44′ by a width of the chamber region82of the secondary airbag chamber64.

Referring toFIG.14and again toFIG.3B, according to several aspects an airbag assembly150is modified from the one-way multiple cushions and chambers airbag assembly45, with components similar to the one-way multiple cushions and chambers airbag assembly45indicated by an apostrophe symbol. The airbag assembly150includes an airbag body152having a first chamber portion154and a second chamber portion156. The first chamber portion154and the second chamber portion156together define a first or primary airbag chamber158. A tether160is substantially centrally positioned within the airbag body152and may extend from a162to a gas fill inlet164. The first chamber portion154and the second chamber portion156are in fluid communication as the tether160acts to internally structurally stiffen the airbag body152when the airbag body152is fully inflated as shown and provides substantially no separation of the gas in the first chamber portion154and the second chamber portion156.

The airbag body152deflates following a collision event by allowing the gas60′ to flow outwardly from the first chamber portion154and the second chamber portion156through a vent hole166. The vent hole166is sized to allow deflation of the airbag body152. In addition to the primary airbag chamber158, the airbag body152further includes a secondary airbag chamber168. A connecting wall170of the primary airbag chamber158creates an inner face172of the secondary airbag chamber168. When fully inflated the secondary airbag chamber168defines a supplementary cushion volume174which is retained during initial collapse of the primary airbag chamber158. The secondary airbag chamber168is therefore oppositely positioned with respect to the secondary airbag chamber64of the one-way multiple cushions and chambers airbag assembly45.

The gas fill inlet164opens into the secondary airbag chamber168supplying a flow of the gas60′ under pressure used to first fill the secondary airbag chamber168and then fill the primary airbag chamber158of the airbag body152. The gas60′ is supplied from a gas generator such as the pyrotechnic device24′ located adjacent to and outside of the airbag body152. As the gas60′ enters the secondary airbag chamber168the gas60′ flows toward the inner face172of the secondary airbag chamber168and enters the first one-way vent valve74′ which penetrates the connecting wall170allowing a first portion of the gas60′ as the gas flow76′ into the primary airbag chamber158. According to several aspects the second one-way vent valve78′ also penetrates the connecting wall170allowing a second portion of the gas60′ as the gas flow80′ to enter the primary airbag chamber158. According to several aspects, the first one-way vent valve74′ and the second one-way vent valve78′ as configured in the airbag assembly150individually provide a gas interconnection passage between the secondary airbag chamber64and the primary airbag chamber54.

During deflation of the airbag body152, the gas60′ in the primary airbag chamber158flows outwardly from the first chamber portion154and the second chamber portion156through the vent hole166. The gas60′ then exits the secondary airbag chamber168in the same direction of flow between the secondary airbag chamber168toward the primary airbag chamber158as shown by the gas flow76′ and the gas flow80′. Similar to the one-way multiple cushions and chambers airbag assembly45, the first one-way vent valve74′ and the second one-way vent valve78′ restrict exiting gas flow from the secondary airbag chamber168to maintain the supplementary cushion volume174during the collision event and the airbag deployment event.

According to several embodiments, the secondary airbag chamber64,168is a non-leakage chamber that will be inflated along with the primary airbag chamber54,158and the secondary airbag chamber64,168exhibits no or little leakage during the airbag deployment event through the end of the motion of the occupant during the collision event. The secondary airbag chamber64,168provides additional protection for higher severity impacts or for heavier occupants and mitigates against the airbag body bottoming out while providing a retained cushion to absorb impact energy.

The airbag assemblies of the present disclosure cushion can be applied to all the current airbag designs including driver airbags, passenger airbags, side impact airbags, and front center airbags. The secondary air cushions of the present disclosure can hold an inflated airbag pressure longer inside the airbag body and have little or no leakage of air pressure while the primary chamber is deflating. With the smaller and stiffer secondary cushions, the occupant may be further protected when the primary airbag is losing its pressure and near bottoming out. Using the secondary airbag chamber of the present disclosure, the airbag body can maintain its contacting surface with the occupant's head during airbag deflation and thereby reduce upward forces acting on the occupant's chin which could otherwise induce a larger neck bending moment.

With an additional pocket cushion inside the airbag, the airbag and the occupant maintain a better contact surface along the airbag surface and thereby reduce a neck load when the airbag has too much contact surface under the chin of ATD. The secondary airbag chamber will inflate along with the primary airbag chamber and the secondary airbag chamber exhibits no or little leakage. The secondary airbag chamber will therefore provide additional protection for higher severity impact events or for heavier occupants and prevent the airbag from bottoming out while providing a cushion to absorb impact energy.

A one-way multiple cushions and chambers airbag assembly of the present disclosure offers several advantages. These include a secondary and no-leakage chamber which will be inflated along with the primary chamber and the secondary chamber will have none or little leakage. The secondary chamber provides additional protection for higher severity impacts or for a heavier occupant and prevents the airbag from bottoming out while also providing a soft cushion to absorb impact energy.