GB2630976A - Airbag cushion systems for vehicles - Google Patents

Abstract

An inflatable cushion 110 of an airbag cushion system 100 has an internal chamber 112, the internal chamber having an opening 113 allowing fluid communication between the internal chamber and an adjacent chamber 111 of the cushion. The cushion also has a throttle arrangement 114, configured to restrict flow of gas from the internal chamber through the opening to the adjacent chamber during an impact event. The throttle may permit flow of gas from the adjacent chamber to the internal chamber during inflation (figure 2A) and restrict flow of gas from the internal chamber to the adjacent chamber to a deflation flow rate (figure 2B), possibly when the inflated internal chamber is struck by an occupant. The throttle may comprise an unbiased check valve with one or more apertures (318, figure 3). The airbag cushion may comprise first and second internal chambers (412, 422, figure 4), each provided with separate throttles (414, 424) possibly providing different deflation flow rates.

Description

AIRBAG CUSHION SYSTEMS FOR VEHICLES

TECHNICAL FIELD

The present disclosure relates to airbag cushion systems for vehicles. Aspects of the invention relate to a curtain airbag cushion system for a vehicle, to a curtain airbag system comprising a curtain airbag cushion system and to a vehicle having a curtain airbag system or a curtain airbag cushion system.

BACKGROUND

It is known to provide vehicle occupant restraint systems such as airbag systems in vehicles. Such systems are inflated on detection of a collision or rapid deceleration of the vehicle, and protect the occupants or cargo of the vehicle from injury or damage. Known airbag systems are able to deflate on impact of an occupant or a body region or head of an occupant on the airbag, to cushion impact during the collision.

In known vehicle airbag systems, different regions, zones or components of a vehicle may be provided with different types of airbag systems. In certain types of vehicles, it may be useful or necessary, or mandated by a safety regulation, to provide airbag systems which either do not deflate at all during or after the collision and/or impact by an occupant, or are required to remain at least partially inflated throughout the collision and potential impact by an occupant. However, in such previously considered airbag systems, after the vehicle occupant contacts the airbag cushion, the return or bounce-back velocity of the vehicle occupant off or away from the cushion may be higher than ideal, because of the required lack of deflation of the airbag cushion It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a curtain airbag cushion system for a vehicle, a curtain airbag system comprising a curtain airbag cushion system and a vehicle having a curtain airbag system or a curtain airbag cushion system.

According to an aspect of the present invention there is provided a curtain airbag cushion system for a vehicle, comprising: an inflatable cushion, the cushion comprising an internal chamber, the internal chamber comprising an opening allowing fluid communication between the internal chamber and an adjacent chamber of the cushion; and a throttle arrangement configured to restrict flow of gas from the internal chamber through the opening to the adjacent chamber during an impact event.

An advantage of this system is that the bounce or return of the vehicle occupant or cargo after contacting the internal chamber of the airbag cushion may be significantly reduced, providing more gradual cushioning and potentially reducing injury, whilst still maintaining the required inflation overall of the whole airbag cushion.

Optionally, the throttle arrangement is configured to permit flow of gas from the adjacent chamber to the internal chamber during inflation.

This allows the restriction of gas flow out of the internal chamber, but permission of gas flow into the internal chamber (during inflation); this means that the internal chamber can still inflate quickly to fulfil the normal airbag cushion function, but deflation is slowed, providing more gradual cushioning.

In embodiments, the throttle arrangement is configured to restrict flow of gas from the internal chamber to the adjacent chamber to a deflation flow rate, and to permit flow of gas from the adjacent chamber to the internal chamber at an inflation flow rate.

Optionally, the throttle arrangement comprises a throttle element, the throttle element having an open configuration for permitting gas flow from the adjacent chamber to the internal chamber, and a closed configuration for restricting flow of gas from the internal chamber to the adjacent chamber. The throttle element may be a vaned or aerodynamic or aero-operated element. The open/closed configuration may be a stowed/deployed or repressed/actuated configuration.

In an embodiment, the throttle element is mounted to a side wall of the cushion, and comprises a movable baffle which is configured to be movable towards the side wall into the open configuration by gas flowing from the adjacent chamber to the internal chamber, and to be movable to the closed configuration by gas flowing from the internal chamber to the adjacent chamber. The baffle may be a vane. The throttle element may be coupled, fastened or attached to the side wall. The baffle may be hingedly mounted or coupled to the side wall.

Optionally, the throttle element comprises a check valve. In an embodiment, the throttle element comprises an unbiased check valve. The throttle element may comprise a one-way valve.

In embodiments, the throttle element comprises one or more apertures, sized to determine in the closed configuration the deflation flow rate. This allows the deflation flow rate to be tuned by the size of the aperture, thereby providing a more accurate deflation rate to optimise cushioning. The apertures may be shaped, configured, or arranged to determine the deflation flow rate.

Optionally, the internal chamber is a first internal chamber and the cushion comprises a second internal chamber, the second internal chamber comprising a second chamber opening allowing fluid communication between the second internal chamber and the adjacent chamber of the cushion; and a second throttle arrangement configured to restrict flow of gas from the second internal chamber through the second chamber opening to the adjacent chamber during the impact event.

This allows for separate or different impact zones in the airbag cushion.

In an embodiment, the second throttle arrangement comprises a second throttle element comprising one or more apertures, the second throttle element apertures sized to determine a deflation flow rate different from the deflation flow rate determined for the first internal chamber.

This provides different impact zones with different deflation characteristics, for example to cater for different types or size of occupant or cargo.

According to another aspect of the invention, there is provided a curtain airbag system comprising the curtain airbag cushion system of any preceding aspect or embodiment, and: an impact sensor system; and an airbag cushion inflation system, configured to input gas into the inflatable cushion.

According to another aspect of the invention, there is provided a vehicle comprising the curtain airbag cushion system of any preceding aspect or embodiment.

According to another aspect of the invention, there is provided an airbag cushion system for a vehicle, comprising: an inflatable cushion, the cushion comprising: an impact section; an adjacent section; a boundary element dividing the impact and adjacent sections; and an opening allowing fluid communication between the impact and adjacent sections, wherein the opening comprises a throttle arrangement configured to restrict flow of gas from the impact section to the adjacent section. Optionally, the throttle arrangement is configured to allow flow of gas from the adjacent section to the impact section.

According to another aspect of the invention, there is provided an airbag cushion system for a vehicle, comprising: an inflatable cushion, the cushion comprising a chamber, the chamber comprising an opening allowing fluid communication between the chamber and an adjacent chamber of the cushion; and a throttle arrangement configured to restrict flow of gas from the chamber to the adjacent chamber.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination.

That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic representation of an airbag cushion system for a vehicle according to an embodiment of the invention; Figures 2A, 2B and 3 show schematic representations of a throttle element of an airbag cushion system for a vehicle according to an embodiment of the invention; Figure 4 shows a schematic representation of an airbag cushion system for a vehicle according to an embodiment of the invention; and Figure 5 shows a vehicle in accordance with an embodiment of the invention.

DETAILED DESCRIPTION

An airbag cushion system 100 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1. As shown in Figure 5, the airbag cushion system is installed in a vehicle 500.

In this and other embodiments, the airbag cushion system 100 is a curtain airbag cushion system. In vehicles, airbags in certain vehicle interior regions may be optimally deployed or indeed required by regulatory or safety bodies to remain inflated, for a period of time (or indefinitely) after inflation in the event of a collision. This is in contrast to, for example, steering wheel airbags which are typically required to deflate prior to or on contact by the vehicle occupant, usually by venting inflation gas back out of the airbag cushion into the surrounding vehicle interior. One such airbag system that may need to remain inflated is a curtain airbag system used to protect the vehicle occupants from side impacts, from contact with the side of the vehicle, or from debris relating to the windows and the like; curtain airbag systems are typically required or implemented to remain inflated for a period of time after deployment, and are therefore confined, sealed or enclosed in some way, in contrast to the vented cushion characteristics of a steering wheel airbag cushion. Embodiments of the present invention address these inflation maintenance requirements whilst allowing improved cushioning deflation on contact by a vehicle occupant or vehicle contents.

The airbag cushion system has an inflatable cushion 110, which can be inflated with gas on detection of a collision. In this and other embodiments, the inflatable cushion additionally comprises an internal chamber 112 or separate section or region of the cushion. The cushion is therefore, in contrast to previously considered systems, subdivided into this chamber or section 112 and an adjacent chamber or section 111. The chamber 112 may be (or be disposed at) an impact region or section or position of the airbag cushion, i.e. a position optimised to receive contact or impact by the occupant, for example, by the head of a vehicle occupant.

The chamber 112 and adjacent chamber 111 are in fluid communication with each other, so that it is possible for gas to enter and exit the chamber 112 via an opening 113 in a boundary or wall of that chamber. In alternative embodiments, multiple such openings are provided; some of these or each may be provided with throttle arrangements as described below. In one alternative, the opening for allowing gas to inflate the chamber 112 may be a different opening from that allowing throttled deflation of the chamber; the first opening may for example be provided with a one-way valve arrangement to prevent deflation via the first opening. In other alternatives, the opening is positioned elsewhere than generally in the plane of the cushion, along a boundary of the chamber; the opening may for example be above the chamber, discharging gas into a separate chamber or separate inflation super-section.

A throttle arrangement 114, in this embodiment provided at the opening 113 between the chamber 112 and the adjacent or outer chamber 111, is configured to restrict flow of gas from the internal chamber through the opening to the adjacent chamber, during an impact event.

This feature is designed to allow the improved cushioning advantages of embodiments of the invention; the chamber 112 can effectively be vented into the adjacent or surrounding chamber, giving a venting deflation effect, whilst the overall airbag cushion stays inflated, in order to meet that requirement. This potentially reduces the bounce-back effect that may be experienced by a vehicle occupant on impact compared with known cushions which are required to remain inflated after collision and/or contact with a vehicle occupant. By internally venting the chamber back into the airbag cushion in this manner, and in embodiments with appropriate tuning of the restraint system, injuries to occupants may be reduced. That is, while the chamber 112 may be located in the cushion 110 to be in the likely impact zone by a vehicle occupant and on impact produce an initial relatively high deceleration, the venting of that chamber into the adjacent wider area reduces the build up of pressure at the point of impact that would otherwise cause a rebound. The vented gas instead further fills the cushion 110 which remains intact to continue to serve its role in shielding from debris etc. In addition, this arrangement allows the pressure within the airbag cushion to be reduced in comparison with previously considered systems; the required pressure sufficient to initially prevent injury to the vehicle occupant is provided at the point of impact by the inflated chamber 112 being unable to immediately vent at the time or point of impact, because of the throttle 114. This has the effect of temporarily artificially increasing the pressure in the chamber 112. Advantages of having a lower overall cushion pressure requirement include that the cushion can be inflated more quickly on collision detection, and potential failure modes may be reduced.

The throttle arrangement 114 may be any device, arrangement of material of the textile or structure of the cushion, or other means which provides some intentional or controllable restriction on the flow of gas out of the chamber 112. In one alternative, the throttle arrangement may be a known one-way valve, of a type suitable for deployment in an airbag cushion system without risking damage to an occupant on impact. In another alternative, the throttle arrangement may be a membrane or other sealing or enclosing feature which is breakable on reaching a threshold pressure (or other impact characteristic) so that on impact of the occupant, the seal is broken and the chamber can be deflated into the adjacent chamber via the resultant opening.

This arrangement in effect provides a kind of valve within the airbag allowing differential pressures and controlled venting/flow within what would otherwise be an open or unrestricted airbag cushion. In an embodiment, the throttle arrangement is configured to permit flow of gas from the adjacent chamber to the internal chamber during inflation. This has the advantage that the inflation flow rate is relatively unimpeded, so that rapid inflation is still permitted, but that the deflation flow rate of the chamber 112 is restricted in the manner described above. This effect provides a kind of one-way valve, in the manner of a check valve. The throttle arrangement can be in effect an unbiased check valve -in embodiments there is no mechanical feature which biases the valve closed again after it has been opened. A description of one such embodiment is set out below with reference to Figures 2A and 2B.

In an alternative embodiment, the throttle can be a more simple arrangement which does not have a one-way valve effect, instead restricting flow in either direction; for the necessary inflation on collision to be effected, an increased inflation pressure or method can be used, or a dedicated inflation arrangement for the chamber 112.

In another alternative embodiment, the unrestricted input flow rate may be provided at a first opening in the chamber 112, which is then sealed or provides a one-way shut-off arrangement to prevent exit of gas through that opening, and the restricted output flow rate provided at a second opening, having a one-way arrangement in the other direction so that inflation is not permitted through that second opening.

Figure 2A and 2B show a schematic representation of a throttle element 214 of an airbag cushion system 100 for a vehicle according to an embodiment of the invention. This throttle arrangement 200 restricts flow of gas from the internal chamber to the adjacent chamber to a deflation flow rate, and permits flow of gas from the adjacent chamber to the internal chamber at an inflation flow rate. In this embodiment, this is effected by providing a throttle element 214 which can be actuated by the gas flow 216/217 itself. The throttle element 214 has an open or stowed or deactivated configuration shown in Figure 2A for permitting gas flow 216 from the adjacent chamber 111 to the chamber 112 (shown in Figure 1); the throttle element 214 does not significantly impede the gas flow 216 during inflation of the chamber 112. The element also has a closed or deployed or activated configuration shown in Figure 2B, for restricting (but not necessarily completely preventing) flow of gas 217 from the internal chamber to the adjacent chamber.

In embodiments, the change between the open/closed configurations is at least in part effected by the flow of gas itself. Here the throttle element 214 is a movable baffle, but could be a vane, flap or fin or a feature affected by aerodynamic pressure and/or drag which allows the opening/closing, stowage/deployment or (de)activation according to the direction of the gas flow. In this embodiment, the baffle 214 is mounted or coupled to a side wall 212 of the cushion, for example by a hinge disposed at the base of the baffle, and is configured to be movable towards the side wall into the open configuration by gas flowing from the adjacent chamber to the internal chamber; the input flow of gas pushes the baffle against the wall of the cushion. If the baffle is not deployed or is open, the input gas is unimpeded in any case; if the baffle is deployed or closed, the input gas pushes it down to open the input channel. The length or width of the baffle is greater than the diameter of the cushion, and the baffle is mounted so that at a greatest extent of deployment of the baffle, the angle of the baffle with the mounting side wall does not extend beyond 45 degrees, meaning that the baffle will only ever hinge back downwards towards the side wall on input of gas in the direction 216.

In contrast, when gas flow is in the other direction 217, the baffle if deployed or closed and prevents exit of the gas from the chamber, by blocking the opening or channel between the side walls. If the baffle is not yet deployed or is open, the drag effect of the gas exiting the chamber in the direction 217 on the tip of the baffle 214 (see Figure 2a) will lift the baffle from its open or stowed configuration to its deployed or closed configuration shown in Figure 2B.

Figure 3 shows a schematic representation of a throttle element 314 of an airbag cushion system 300 for a vehicle according to an embodiment of the invention. The throttle element is provided with at least one aperture 318; this means that in the closed configuration shown in Figure 2B, there is at least some of the gas in the deflation direction 217 allowed to exit the chamber. This feature in this embodiment provides the desired effect of a restricted deflation rate. The a perture(s) 318 are sized to determine the deflation flow rate; this tuning can be done in concert with other elements of the airbag system, and indeed with other elements of the vehicle, in order to provide the required instantaneous pressure in the chamber 112 to provide sufficient cushioning, whilst also allowing gradual deflation to prevent bounce-back.

Once the airbag is deployed, the inflation gas passes through open side of the throttle arrangement and in doing so the airbag changes shape from a flat rolled up piece of fabric to a 3D cushion. The change in shape may hold the throttle arrangement in place against the internal side of the airbag. An impact against the cushion forces the gas through the valve (or through the restriction apertures, allowing slow deflation of the internal cushion 112. On release of the impact, the potentially now higher pressure in the adjacent part 111 of the airbag may push gas back into the internal cushion. This return will be primarily through the same route that is followed on initial inflation of the airbag. As such there is no, or negligible, restriction on the re-inflation of the internal cushion 112 and it potentially expands again to near its full 3D shape. That will again have the effect to close the valve 214 so the internal chamber 112 can operate again as described above if there is a further occupant impact.

Figure 4 shows a schematic representation of an airbag cushion system 400 for a vehicle according to an embodiment of the invention. In this embodiment, two separate chambers 412 and 422 are provided in the same airbag cushion 410. Here, each chamber has its own dedicated opening 414 and 424 respectively, which can be provided with a throttle arrangement as described above, in order to provide a restricted outward flow rate and thereby give the advantages described above for improved cushioning and lower overall airbag pressure, but here in two separate impact sections or regions of the airbag cushion. In embodiments the chambers can be separated by some distance inside the adjacent chamber or overall cushion as shown in Figure 4, or can be immediately adjacent, for example separated only by a single boundary feature between the chambers. In an alternative embodiment in which the chambers are adjacent, throttle arrangements such as those described above and with reference to Figures 1 to 3 can be provided to span the opening (or indeed to require only one opening) of the two chambers. For instance, a movable baffle similar to that in Figure 2, can be provided to seal, in the closed configuration, both chambers 412 and 422. In such an embodiment, a dedicated aperture (or set thereof) such as that 318 shown in Figure 3 can be provided one for each chamber.

In this manner, two separate chambers associated with different impact areas can be provided. This allows for the provision of different characteristics for the separate impact areas. In an embodiment, a throttle arrangement or aperture therein can be tuned or used to determine a deflation flow rate for the first chamber 412 which is different from that of the second chamber 422. This can be used to provide different deflation characteristics for example for different potential occupants. For instance, a slower deflation rate, generating a higher initial impact pressure, can be provided in the second chamber which can be positioned at a relative height in the vehicle intended to address a taller vehicle occupant, making the assumption that this taller occupant will have greater inertia than a less tall occupant.

Figure 5 illustrates a vehicle 500 according to an embodiment of the present invention. The vehicle 500 comprises an airbag cushion system 100 as illustrated in Figure 1. The vehicle has an impact sensor system 542 for detecting a collision or rapid deceleration status for the vehicle. Data from the impact sensor system can be used to trigger the airbag cushion inflation system 544, which is configured to input gas into the inflatable airbag cushion system 540 in the event of a collision. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims (12)

1. CLAIMSA curtain airbag cushion system for a vehicle, comprising: an inflatable cushion, the cushion comprising a first internal chamber, the internal chamber comprising an opening allowing fluid communication between the first internal chamber and an adjacent chamber of the cushion; and a throttle arrangement configured to restrict flow of gas from the first internal chamber through the opening to the adjacent chamber during an impact event.
2. 2. An airbag cushion system according to Claim 1, wherein the throttle arrangement is configured to permit flow of gas from the adjacent chamber to the first internal chamber during inflation.
3. 3. An airbag cushion system according to Claim 1 or Claim 2, wherein the throttle arrangement is configured to restrict flow of gas from the first internal chamber to the adjacent chamber to a deflation flow rate, and to permit flow of gas from the adjacent chamber to the first internal chamber at an inflation flow rate.
4. 4. An airbag cushion system according to any preceding claim, wherein the throttle arrangement comprises a throttle element, the throttle element having an open configuration for permitting gas flow from the adjacent chamber to the first internal chamber, and a closed configuration for restricting flow of gas from the first internal chamber to the adjacent chamber.
5. 5. An airbag cushion system according to Claim 4, wherein the throttle element is mounted to a side wall of the cushion, and comprises a movable baffle which is configured to be movable towards the side wall into the open configuration by gas flowing from the adjacent chamber to the first internal chamber, and to be movable to the closed configuration by gas flowing from the first internal chamber to the adjacent chamber.
6. 6. An airbag cushion system according to Claim 4 or Claim 5, wherein the throttle element comprises a check valve.
7. 7. An airbag cushion system according to Claim 6, wherein the throttle element comprises an unbiased check valve.
8. 8. An airbag cushion system according to any of the Claims 4 to 7 when dependent on Claim 3, wherein the throttle element comprises one or more apertures, sized to determine in the closed configuration the deflation flow rate.
9. 9. An airbag cushion system according to any preceding claim, wherein the cushion comprises a second internal chamber, the second internal chamber comprising a second chamber opening allowing fluid communication between the second internal chamber and the adjacent chamber of the cushion; and a second throttle arrangement configured to restrict flow of gas from the second internal chamber through the second chamber opening to the adjacent chamber during the impact event.
10. 10. An airbag cushion system according to Claim 9 when dependent on Claim 3, wherein the second throttle arrangement comprises a second throttle element comprising one or more apertures, the second throttle element apertures sized to determine a deflation flow rate different from the deflation flow rate determined for the first internal chamber.
11. 11. A curtain airbag system comprising the curtain airbag cushion system of any preceding claim, and: an impact sensor system; and an airbag cushion inflation system, configured to input gas into the inflatable cushion.
12. 12. A vehicle comprising the curtain airbag cushion system of any of the Claims 1 to 10, or the curtain airbag system according to Claim 11.