DE10392576T5 - Airbag and method for deploying an airbag - Google Patents

Abstract

airbag, which is suitable as an overhead airbag in a motor vehicle to be used, wherein the airbag at least one attachment element having, by a tearing at the inflation of the airbag tear seam on Airbag is attached, wherein the attachment member with an am Motor vehicle mounted mounting arrangement interacts, to secure the upper part of the airbag in position, and wherein the airbag is connected to an inflator assembly and at least a gas flow line leading from the inflator assembly for gas is present, which extends into the interior of the airbag and is suitable for inflating the airbag following the Tear the tear seam of Airbag withdrawn to become.

Description

The The present invention relates to an airbag, and more particularly to an airbag. which is intended for mounting in the roof of a motor vehicle and is capable of getting into a position in front of an occupant of the Vehicle to move when it comes to an accident.

Even though It is convenient to have an airbag mounted in the roof of a motor vehicle is to provide with the intention that the airbag at his Inflate to a position in front of an occupant of the vehicle will, can difficulties arise with such airbags, since there is a risk that the Airbag itself while the hull and the head of the occupant of the vehicle, which is through the airbag protected to be, during one Impact situation forward moved, an undesirable Force transmitted to the head of the occupant which causes the head to be pushed backwards in relation to the trunk and neck injuries caused.

The The present invention seeks to provide an improved airbag assembly provide.

According to this The invention provides an airbag suitable for used as an overhead airbag in a motor vehicle be, wherein the airbag has at least one attachment element, that by a tear seam, which is adapted to tear when inflating the airbag, on Airbag is attached, wherein the attachment member suitable is, with an attachment provided on the motor vehicle cooperate to the upper part of the airbag in its position attaching, wherein the airbag connected to an inflator assembly is and at least one gas flow line for gas is present from the inflator, wherein the gas flow line extends into the interior of the airbag and is adapted to the Inflating the airbag following the tearing of the tear seam withdrawn from the airbag to become.

Preferably extends the gas flow line from the exterior of the Airbags through an opening formed in the airbag inside the airbag and has a free end inside the airbag, thereby the line is suitable, completely withdrawn from the airbag to become.

suitably is the opening provided with a valve to at least partially seal the opening, if the wire is completely withdrawn from the airbag is.

Preferably is the part of the airbag that is the lowest at its deployment Part of the airbag should form, with at least one lower tear seam or a Band provided, which is adapted to the extent of the inflation of the lower Part of the airbag initially restrict, and is suitable while of inflation of the airbag.

suitably is the tear seam, which connects the attachment approach to the airbag, suitable for to tear, when inside the airbag reaches a first relatively low pressure is, and are the lower tear seams to it suitable to tear, if there is a higher pressure inside the airbag.

Preferably the low pressure is between 20 and 30 kPa and the higher pressure between 40 and 50 kPa.

suitably is a middle part of the airbag with a stitching or strapping provided the extent of that Part of the airbag when inflating to a minimum.

advantageously, For example, the inflator assembly is suitable for an initial one Level of inflation of the airbag a relatively low gas flow rate and while a subsequent Level of inflation of the airbag a higher gas flow rate provide.

The The invention also relates to an airbag as described above which, when in a collapsed state, the lower part of the airbag is rolled up and the upper part of the airbag Airbags is folded zigzag or accordion-like, with the Gas supply line an opening inside the concertina folded portion of the airbag having.

The Invention also relates to a method for deploying an airbag, wherein the airbag has an upper part provided with an attachment member is that by a first tear seam connected to the airbag, and that the airbag in its position attaches, wherein the airbag has a lower part, which with at least one lower tear seam or a band is provided to control the deployment of the airbag, wherein the method for deploying the airbag is the following steps comprising: Injecting gas into the airbag, so that a substantial portion of the Gas flows to the lower part of the airbag and the lower part of the Airbags inflates, without breaking the tear seams, the gas then flows to the upper part of the airbag to the Inflate the upper part of the airbag and with the attachment element connected tear seam to break up, and the river of Gas then serves to increase the pressure inside the airbag to every lower tear seam or break any lower band.

In order to the invention can be more easily understood, and thus more Characteristics of which can be recognized The invention will now be described with reference to the accompanying drawings by way of example, wherein:

1 is a perspective view of an airbag according to the invention prior to its folding,

2 an illustrative front view of the airbag of FIG 1 is that illustrates gas flows in the airbag when deployed,

3 a diagrammatic sectional view taken along the line A-A of 2 is that illustrates the airbag in the housed condition prior to deployment,

4 a 3 corresponding view illustrating the state of the airbag in an initial stage during deployment,

5 a 4 corresponding view, which shows the airbag in a subsequent stage in the unfolding,

6 a 5 corresponding view showing the airbag at a later stage of deployment,

7 a 6 corresponding view illustrating the airbag in a final stage of deployment, and

8th is a diagrammatic view of a flapper valve.

With reference to 1 The accompanying drawings show an airbag 1 formed of two superimposed layers of fabric, which is a rear surface 2 and a front surface 3 define. The airbag has a generally rectangular shape as illustrated. The airbag is an overhead airbag. At the top edge 4 of the airbag is a mounting tab 5 provided. The attachment tab 5 is a tab made of fabric, which by tear seams 6 attached to the main body of the airbag. The attachment tab 5 can be engaged with a mounting arrangement such as a hook or a mounting bar, which, as will become clear from the following description, is provided in the roof of the motor vehicle to the airbag 1 to fix it in position inside the vehicle. The tear seams 6 are designed so that they will rupture when the pressure inside the airbag exceeds a first threshold, which threshold is preferably in the range of 20 to 25 kPa or in the range of 20 to 30 kPa. The attachment tab 5 is then released from the hook or rod. Thus, the attachment tab forms 5 a detachable attachment for the upper part of the airbag, which is released in response to the inflation of the airbag.

Near the top edge 4 of the airbag 1 are two gas inlet openings 7 . 8th provided. Through each of the openings 7 . 8th is a respective gas supply line 9 . 10 used. The gas supply conduit extends into the interior of the airbag and terminates with a free end located inside the airbag. The free end is the end of the conduit inside the airbag, this end of the conduit not being connected to the airbag. It is desirable that the gas lines 9 . 10 are formed of a stiff but flexible material. The material used may thus be much stiffer than the material used for an ordinary airbag, and may in fact be formed of a material similar to that used in the manufacture of extinguishing tubes. Preferably, the material is of such a type that the gas inlet conduits 9 . 10 have a degree of rigidity, although the lines should not be completely rigid, but should be able to bend. The wires 9 . 10 should also be able to be folded, so that the ge entire airbag can be compact folded compact to be housed in a housing.

The back fabric layer 2 and the front fabric layer 3 are in a central region of the airbag 1 by stitching or strapping 11 connected with each other. The stitching or strapping 11 is provided so that when the airbag is inflated, the middle portion of the airbag has a thickness determined by the length of the stitching or strapping.

The lowest part of the airbag is with a re-entrant fold or fold 12 provided, which is similar to a gusset formed by the bottom of the airbag, which actually forms two "wings" at the lowermost part of the airbag, these wings at the lowermost part of the airbag by a tear seam 13 connected to each other. Another tear seam 14 is so at a point over the re-entrant fold or fold 12 provided that it extends parallel to the lower part of the airbag. The tear seams 13 and 14 at the lowermost part of the airbag are designed to initially restrict the amount of inflation of the lower part of the airbag. The tear seams 13 and 14 however, are of such a nature that they will rupture when the pressure inside the airbag exceeds a second threshold which is higher than the first threshold and is typically in the range of 40 to 50 kPa. The lower part of the airbag can then inflate completely.

Referring now to 2 it is intended that the gas supply lines 9 . 10 with a gas distribution manifold 15 which should be a gas generator or an inflator 16 contains or is associated with it. It is envisaged that gas will initially flow through the gas flow lines as the airbag is inflated 9 . 10 will flow, and the gas due to the location of Gasflußleitungen inside the airbag 1 after a preliminary stage during inflation, will be caused by the strapping area 11 to flow down to the bottom of the airbag. The lowest part of the airbag will inflate to a limited extent. The gas will then flow upwardly during the next stage of inflation of the airbag to inflate the upper portion of the airbag. As the upper part of the airbag inflates, the tear seam becomes 6 holding the attachment tab 5 connects with the main part of the airbag, tear. Thus, the main part of the airbag is no longer through the connecting tab 5 be connected to the vehicle. As will be described in more detail below, the pressure inside the airbag will continue to increase until the second threshold is reached and the tear seams 13 . 14 in the lower part of the airbag tear, which allows the lower part of the airbag to inflate completely, while the main part of the airbag can then move downwards, the gas supply lines 9 and 10 be withdrawn sliding from the airbag until they are completely withdrawn. The free end of each line is no longer inside the airbag. Thus, the airbag can be completely free and completely separated from the rest of the vehicle in the described embodiment. When this happens, there is no physical connection between the airbag and the vehicle.

The exact pressure at which the tear seams 13 and 14 can be selected depending on the desired inflating property of the airbag. For example, the top of the two seams, the seam 14 , at a relatively low pressure, so that the lower part of the airbag can partially inflate to provide a degree of protection at a relatively early stage, while the lowermost seam, the seam 13 , only ruptures at a relatively high pressure.

Referring now to 3 It should be understood from the appended drawings that the airbag is when the airbag 1 is mounted in a position in a motor vehicle, in a recess or a housing 20 that in the roof 21 a motor vehicle is provided is received. The attachment tab 5 stands with a hook or a rod inside the recess or the housing 20 engaged. The lowermost part of the airbag is rolled up, and more specifically rolled up in a sense, as if it had been rolled up from the front of the vehicle, around a rolled-up section 22 to build. The uppermost part of the airbag is folded in a zigzag or accordion-like manner to form a "concertina" section 23 to build. The gas flow lines 9 . 10 have their open ends either in the accordion section 23 alternatively have or have openings in their side walls, with the accordion section 23 keep in touch.

One must understand that when operating the gas generator 16 inside the gas supply manifold 15 Gas in the gas supply lines 9 and 10 will flow. That gas is initially in the accordion section 23 of the folded airbag are injected. The accordion section will immediately begin to expand, causing the rolled-up section 22 is still pushed down in the rolled-up state. The lowest part of the housing 20 that has two doors 24 . 25 exists, jumps up, and the rolled-up section 22 exits the roof of the vehicle to fall down in front of the occupant to be protected by the airbag during the concertina section 23 is inflated. After inflating the accordion section 23 becomes the rolled up section 22 begin to inflate, with the rolled-up section 22 again, as if it were directed to the front of the vehicle, unrolls. Gas then flows as above with reference 2 described inside the airbag. The airbag then reaches the as in 5 To be stood, in which the airbag completely from the recess or the housing 20 extends down. The combination of the tear seams provided at the lower part of the airbag 13 . 14 and strapping 11 ensures that the airbag, while moving downwards, has a limited "thickness" measured in the vehicle's axial direction. This helps to ensure that the airbag is deployed even in an appropriate position in front of the occupant to be protected when this occupant leans forward or is "out of position".

When the rolled up section 22 When the airbag is fully unrolled, the pressure in the air bag will start to rise, and when the pressure is in the range of 20 to 25 kPa or 20 to 30 kPa, the tear seam will become 6 tear, causing the attachment tab 5 from the main part of the airbag 1 is disconnected. The airbag 1 is now no longer connected to the vehicle itself, as the gas lines 9 . 10 only through openings 7 . 8th extend into the interior of the airbag and provide no firm connection. In this stage, the gas supply lines extend 9 . 10 still inside the airbag 1 However, the gas lines are only through openings in the airbag 1 used, so that the airbag 1 from the case 20 can move away while the gas lines 9 . 10 from Airbag to be withdrawn.

The pressure inside the airbag will increase until a pressure in the range of 40 to 50 kPa is reached, at which time the tear seams 13 . 14 in the lower part of the airbag will tear. The lower part of the airbag then inflates completely.

In a modified embodiment, the seam 14 at a pressure in the range of 15 to 30 kPa, so that the lower part of the airbag can inflate in an early stage.

When an inmate 26 To be protected by the airbag, moved forward and colliding with the airbag, the occupant may exert a generally forward and a generally downward force on the airbag. When a generally downward force is applied to the airbag, the entire airbag is free to move downwardly, with the gas supply lines completely retracted from the airbag. Thus, the airbag 1 as in 7 be completely separated from the rest of the vehicle. Of course, the airbag will be located between the occupant of the vehicle and the vehicle's body in front of that occupant. This structure may be the steering wheel when the occupant is the driver or the dashboard when the occupant is a passenger in the front seat. Alternatively, the body may be the front seats of the vehicle when the occupant is a rear seat occupant.

The inflated airbag forms a "cushion" between the occupant and the body of the vehicle in front of the occupant. The openings 7 and 8th of which the gas supply lines 9 and 10 retracted, serve as vents, although, if desired, inside the airbag as in 8th shown check valves or "flap" valves 27 can be provided, which serve to seal or at least reduce the flow of gas through these openings as soon as the gas supply lines 9 and 10 were withdrawn from it. This in 8th shown flap valve 27 is with the opening 7 connected. The flap is next to the opening 7 on the fabric of the airbag 1 attached and designed so that the flapper valve 27 then, if the gas line 9 withdrawn from the airbag, will move to a position in which there is the opening 7 at least essentially seals.

In a preferred embodiment of the invention, the gas generator 16 be adapted so that the gas generator during the initial stage of inflation, while the concertina section 23 is inflated, only a relatively low gas flow rate, and during the subsequent stage of inflation, when the rolled-up portion is unrolled and inflated, provides a much higher gas flow rate. This can be achieved by using two gas generators operated sequentially, the first gas generator being a relatively "gentle" gas generator, and a second gas generator operating a predetermined period of time after the first gas generator is actuated, being more aggressive.

Although the invention has been described with reference to an embodiment in which a single gas generator 16 is present and a gas distribution manifold 15 Gas leads to the two gas supply lines, a separate gas generating arrangement can be provided for each gas supply line. In a further modified embodiment, there is only a single gas supply line.

In certain embodiments, the lower tear seams 13 . 14 be replaced by inner tear strips, which limit the initial extent of inflation of the lower part of the airbag and tear when a predetermined internal pressure is reached.

In in the present specification means "comprises" " or consists of "and means "comprising" "including or consisting of".

SUMMARY

An overhead airbag ( 1 ) has an attachment element ( 5 ) which on the means of a tear seam ( 6 ), wherein the tear seam is intended to tear upon inflation of the airbag. A gas flow conduit is provided which extends from the inflator assembly into the interior of the airbag and is adapted to be retracted from the airbag upon inflation of the airbag.

For this 1 the drawing.

Claims (10)

An airbag adapted to be used as an overhead airbag in a motor vehicle, the airbag having at least one attachment member secured to the airbag by a tear seam tearing upon inflation of the airbag, the attachment member cooperating with an attachment assembly provided on the motor vehicle to secure the upper part of the airbag in position, and wherein the airbag is connected to an inflator assembly and at least one gas flow conduit leading from the inflator assembly is provided for gas extending into the interior of the airbag and adapted to to be withdrawn from the airbag upon inflation of the airbag following rupture of the tear seam. Airbag according to claim 1, wherein the gas flow line from the outside of the airbag through an opening formed in the airbag inside the airbag extends and inside the airbag has a free end, whereby the line is suitable, completely withdrawn from the airbag to become. Airbag according to claim 2, wherein the opening with a valve is provided around the opening at least partially seal when the pipe is completely closed withdrawn from the airbag is. Airbag according to one of the preceding claims, in which the part of the airbag, which at its deployment the lowest Part of the airbag should form, with at least one lower tear seam or a Band adapted to the extent of inflation initially restrict the lower part of the airbag, and is suitable while of inflation of the airbag. Airbag according to one of the preceding claims, in to which the tear seam connecting the attachment approach with the airbag suitable to tear, when inside the airbag reaches a first relatively low pressure is, and the lower tear seams to are suitable to tear, if inside the airbag a higher one Pressure is present. Airbag according to claim 5, wherein the low Pressure between 20 and 30 kPa and the higher pressure between 40 and 50 kPa. Airbag according to one of the preceding claims, in which a middle part of the airbag with a stitching or strapping is provided to the extent of that Part of the airbag when inflating to a minimum. Airbag according to one of the preceding claims, in which the inflator assembly is adapted to during a initial Level of inflation of the airbag a relatively low gas flow rate and while a subsequent Level of inflation of the airbag a higher gas flow rate provide. Airbag according to one of the preceding claims, in which in a folded state, the lower part of Airbags rolled up and the upper part of the airbag zigzag or folded like an accordion, wherein the gas supply line has an opening in the Interior of the concertina folded portion of the airbag having. Method for deploying an airbag, wherein the Airbag has an upper part, which with an attachment element is provided, which is connected by a first tear seam with the airbag is and the airbag holds in position, and wherein the airbag a Lower part, with at least one lower tear seam or a band is provided to control the deployment of the airbag, wherein the method for deploying the airbag is the following steps comprising: Injecting gas into the airbag, so that a substantial portion of the Gas flows to the lower part of the airbag and the lower part of the airbag inflates, without breaking the tear seams, taking the gas then flows to the upper part of the airbag to the upper part of the airbag Inflate airbags and break the tear seam connected to the attachment element, and the river of Gas then serves to increase the pressure inside the airbag to every lower tear seam or break any lower band.