GB2422357A

GB2422357A - Airbag system integrated with vehicle ventilation system

Info

Publication number: GB2422357A
Application number: GB0501596A
Authority: GB
Inventors: Thomas Reiter; Marcus Weber; Karl Heinz Sommer; Klaus Peter Kuhne; Jorg Albert; Marc Schock
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2005-01-25
Filing date: 2005-01-25
Publication date: 2006-07-26
Anticipated expiration: 2025-01-25
Also published as: GB0501596D0; GB2422357B

Abstract

A safety arrangement (1) is mounted in a motor vehicle, and the safety arrangement (1) has an air-bag unit (15) which is carried by a lower side of a plenum chamber (12) which supplies air to the windscreen (3) of the vehicle. When the safety arrangement (1) is in an initial condition an air-bag (34) is folded within a housing (16) of the air-bag unit (15), and an upper open end (17) of the housing (16) is sealed by a sheet (36) and a pivotally mounted door (37). The sheet (36) and the door (37) divide the interior of the air-bag unit (15) from the plenum chamber (12). A gas generator (24) is mounted to the side of the housing (16), and when the gas generator (24) is actuated the gas generator (24) generates gas and inflates the air-bag (34). The air-bag (34) exerts an upward force on the lower side of the sheet (36) and the lower side of the door (37) as it inflates, and the sheet (36) and the door (37) each move to form a guiding passage which guides the air-bag 34 upwardly and out from a slot (4) in the dashboard (2) into the cabin of the vehicle to protect an occupant of the vehicle.

Description

DESCRIPTION OF INVENTION

"IMPROVEMENTS IN OR RELATING TO A SAFETY ARRANGEMENT" THE PRESENT INVENTION relates to a safety arrangement, and more particularly relates to a safety arrangement to protect an occupant of a vehicle in the event that a crash situation occurs.

Previously proposed safety arrangements for protecting an occupant seated in the front passenger side of a vehicle have incorporated an air-bag unit which is positioned beneath part of the dashboard of the vehicle which is close to the windscreen. The air-bag unit is mounted in such a way as to allow an air-bag to inflate from the air-bag unit, with the air- bag displacing a grille in the vehicle, which ordinarily allows air from the ventilation system to be blown onto the windscreen, so that the air- bag enters the cabin of the vehicle adjacent the windscreen.

Such a prior proposed safety arrangement is disclosed in International Application WO 2004/045920. This prior proposed safety arrangement has an air-bag unit which is mounted on one side of an air duct of the vehicle, with a moveable door forming one side of the air duct and one side of the air bag unit.

In the event that an accident situation occurs the air bag unit is actuated and a gas generator inflates an air-bag within the air-bag unit. As the air-bag is inflated the air-bag exerts a force on the moveable door, which causes the door to tilt into the air duct. The air-bag may thus inflate into the air duct, and it is guided upwardly by the door, to displace a grille in the dashboard of the vehicle, to enter the cabin of the vehicle.

The present invention seeks to provide an improved safety arrangement for use in a vehicle.

According to the present invention, there is provided a safety arrangement mounted in a motor vehicle, the safety arrangement comprising an air duct that defines a plenum chamber positioned beneath a dashboard in the vehicle to supply air to the windscreen of the vehicle, at least part of the lower side of the plenum chamber carrying an air-bag unit, the air-bag unit containing an air-bag with substantially all of the air- bag being beneath the plenum chamber when the safety arrangement is in a normal condition, there being at least one moveable element which, in an initial position, divides at least part of the interior of the air-bag unit from the plenum chamber, the said at least one element being moveable on deployment of the air-bag from the initial position to a second position in which the air-bag may inflate upwardly into the plenum chamber and out from the plenum chamber into the interior of the vehicle.

Preferably there are a plurality of moveable elements which, in an initial position, divide at least part of the interior of the air-bag unit from the plenum chamber.

Conveniently one of the said moveable elements is a flexible sheet.

Advantageously the said flexible sheet forms a substantially gas tight seal, which seals the interior of the air-bag unit housing from the plenum chamber.

Preferably the said at least one movable element is a door which is pivotally mounted.

Conveniently a slot is formed in a part of the dashboard which defines an upper wall of the plenum chamber, and when the safety arrangement is in a normal condition a grille is fitted within the said slot, and wherein upon deployment of the air-bag the grille is displaced from the slot so that the air-bag may inflate out from the plenum chamber, through the slot, and into the interior of the vehicle.

Advantageously there is at least one reinforcing wall, which provides a surface which the movable element may contact, on deployment of the airbag.

Preferably a gas generator is mounted to a side-wall of the air-bag unit housing, and a gas deflector is mounted within the housing of the air-bag unit, to direct gas from the gas generator to inflate the said air-bag in a direction substantially towards the moveable element.

Conveniently when the safety arrangement is in a normal condition, a minor portion of the air-bag is folded and positioned above the said gas deflector, and a major portion of the air-bag is folded and positioned to one side of the said gas deflector, such that gas from the gas generator inflates the minor portion of the air-bag before the major portion of the air-bag.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a diagrammatic sectional view of a safety arrangement in accordance with a preferred embodiment of the invention, mounted beneath the dashboard of a vehicle and in a normal condition, FIGURE 2 is a view of the safety arrangement of Figure 1, but showing the safety arrangement during an initial stage after it has been actuated, FIGURE 3 is a diagrammatic sectional view of a safety arrangement in accordance with an alternative embodiment of the invention, in a normal condition, FIGURE 4 is a view of the safety arrangement of Figure 3, but showing the safety arrangement during an initial stage after it has been actuated, FIGURE 5 is a diagrammatic sectional view of a safety arrangement in accordance with a further embodiment of the invention, in a normal condition, and FIGURE 6 is a view of the safety arrangement of Figure 5, but showing the safety arrangement during an initial stage after it has been actuated.

Referring initially to Figures 1 and 2, a safety arrangement I is mounted beneath part of a dashboard 2 of a motor vehicle. The part of the dashboard 2 is a part of a dashboard which presents a horizontal surface at the front of the vehicle's cabin, close to the bottom edge of a windscreen 3 of the motor vehicle. The dashboard 2 incorporates an aperture in the form of a slot 4, and a grille 5 is detachably fixed within the slot 4. The grille 5 is of a type which is typically used in a vehicle ventilation system, and presents slots to direct air flowing from the ventilation system onto the windscreen 3.

An air duct 6 is mounted to the lower side of the dashboard 2, beneath the grille 5. The air duct 6 comprises two walls 7, 8 that each depend downwardly from beneath the dashboard 2, on respective sides of the grille 5.

The lower ends of the waIls 7, 8 are inwardly directed to form mounting surfaces 9, 10. A central aperture 11 is formed in the lower side of the air duct 6, between the edges of the mounting surfaces 9, 10.

The duct 6 defines a plenum chamber 12 located between the walls 7, 8 and above the central aperture 11. Air from the ventilation system may be blown through the plenum chamber 12, and through the grille 5 onto the windscreen 3.

A first reinforcing wall 13, which is short relative to the height of the waIl 7 of the duct 6, but thicker with respect to the wall 7 of the duct 6, is attached, within the duct 6, to the lower side of the dashboard 2 adjacent the front edge of the slot 4. A second reinforcing wall 14 is mounted within the air duct 6, at a position adjacent the rear edge of the slot 4. The second reinforcing wall 14 is of generally the same height as the wall 8 of the duct 6, but the second reinforcing wall 14 is substantially thicker than the wall 8 of the duct 6.

In this preferred embodiment, the second reinforcing wall constitutes a grille with apertures to allow air to flow from the plenum chamber 12 to the part of the air duct 6 which is formed by the side wall 8. The purpose of the reinforcing walls 13, 14 will become clear from the description below.

An air-bag unit 15 is carried by the lower side of the air duct 6, and attached to the mounting surfaces 9, 10 of the walls 7, 8 of the air duct 6. The air-bag unit 15 has a substantially U-shaped housing 16 which presents an open upper end 17. The housing 16 has mounting flanges 18, 19 which extend radially outwardly from the upper edge of the U-shaped housing 16, and are attached to the mounting surfaces 9, 10 on the air duct 6. The U-shaped housing 16 has a first side-wall 20 which extends downwardly from the front most flange 18, at an angle inclined towards the front of the vehicle, to a base 21. A mounting aperture 22 is formed in the lower part of the first side- wall 20. The base 21 extends rearwardly from the first side-wall 20, beneath the open upper end 17, to a second side-wall 23. The second side- wall 23, which extends vertically upwards from the base 21 to the rear- most flange 19.

A gas generator 24 is positioned in front of the first side-wall 20 of the U-shaped housing 16. The gas generator 24 has a cylindrical body section 25, with the longitudinal axis of the cylindrical body section 25 being horizontal and substantially parallel to the first side-waIl 20. A cylindrical projection 26 extends outwardly from the side of the cylindrical body section 25, at a point mid-way along the length of the cylindrical body section 25. The cylindrical projection 26 is of slightly reduced diameter to the mounting hole 22 in the first side-wall 20. A generally cylindrical gas diffuser 27 is mounted to the end of the cylindrical projection 26 from the gas generator 24. The gas diffuser 27 has apertures 28 formed in its side-wall, to allow gas to escape from the gas generator 24.

The air-bag unit 15 also comprises a gas deflector 29. The gas deflector 29 is, once again, substantially U-shaped, and has a first side-wall 30, connected to a base 3 1 which is in turn connected to a second side-wall 32.

The first side-wall 30 of the gas deflector 29 incorporates a mounting aperture 33, which is of the same diameter as the mounting aperture 22 in the U-shaped housing 1 5. The first and second side-walls 30, 32 are each inclined rearwardly relative to the base 31, at the same angle of inclination as the first side-wall 20 of the U-shaped housing 16. The gas deflector 29 is dimensioned to fit within the U-shaped housing 16, adjacent the mounting aperture 22 in the first side-wall 20.

The air-bag unit 15 also comprises an air-bag 34 which has an inlet aperture 35.

During assembly of the air-bag unit 15 the diffuser 27 and the cylindrical projection 26 of the gas generator 24 are inserted through the mounting aperture 22 in the first side-wall 20 to extend into the U- shaped housing 16.

The inlet aperture 35 of the air-bag 34 is then placed over the cylindrical projection 26, so that the part of the air-bag 34 surrounding the inlet aperture 35 sits around the cylindrical projection 26, and is in contact with the inside of the first side-wall 20 of the U-shaped housing 16. The mounting aperture 33 in the first side-wall 30 of the deflector 29 is then placed over the diffuser 27 and the cylindrical projection 26, so that the first side-wall 30 sits over the part of the air-bag 34 which surrounds the inlet aperture 35. The first side-wall 30 of the deflector 29 is then fixed in position, so that the part of the air-bag 34 surrounding the inlet aperture 35 is trapped between the first side-wall 30 of the dcflector 29 and the first side-wall 20 of the U- shaped housing 16. The inlet aperture 35 of the air-bag 34 is thus held in position, and a substantially gas- tight seal is formed between the air-bag 34 and the U-shaped housing 16.

Once the inlet aperture 35 of the air-bag 34 has been mounted in position, the air-bag 34 is tightly folded, to fit within the U-shaped housing 16.

The air-bag 34 is folded so that a greater proportion of the air-bag 34 is present between the second side-wall 32 of the deflector 29 and the second side-wall 23 of the U-shaped housing 16, than above the deflector 29. A minor portion of the bag is within and above the deflector 29.

A flexible plastic sheet 36 is attached to one edge of open upper end 17 of the U-shaped housing 16, and in this preferred embodiment the plastic sheet 36 is also attached all the way around the edge of open upper end 17 to form a substantially gas tight seal. When the safety arrangement is in the initial condition the sheet 36 seals the interior of the U-shaped housing 16 from the plenum chamber 12 to prevent dirt and dust from entering the U-shaped housing 16 of the air-bag unit 15. Although the sheet 36 is attached all the way around the edge of the open upper end 17 to form a sealing fit, the sheet 36 is only securely attached to the rear edge of the open upper end 17, adjacent the rear most flange 19. The sheet 36 is attached around the front-most and side edges of the open upper end 17 by a breakable split line. The purpose of this breakable split line will become clear from the following description.

A substantially rigid plastic door 37 is pivotally mounted to the front edge of the central aperture 11 in the duct 6. In this preferred embodiment the door 37 is formed integrally with the duct 6, with a split line extending along each side of the door 37 with the exception of the front edge of the door 37 which has a weakened seam which is not designed to split. The weakened seam allows the door 37 to pivot relative to the rest of the duct 6. The door 37 is in the form of a generally planar plate 38, with an upturned end 39 that is angled approximately at 45 to the plate 38. The door 37 overlies the sheet 36, and closes the central aperture 11. The door 37 thus provides a lower wall of the duct 6, and also helps to seal the open upper end 17 of the air-bag unit 15, to help prevent dirt and dust entering the air-bag unit 15.

When the safety arrangement is in an initial condition, the air-bag 34 is tightly folded within the U-shaped housing 16 of the air-bag unit 15, and substantially all of the folded air-bag 34 is beneath the plenum chamber 12.

In the event that an accident occurs the gas generator 24 is actuated, to generate gas to inflate the air-bag 34. Gas from the gas generator 24 passes out from the apertures 28 in the diffuser 27, and into the volume defined between the walls 30, 31 and 32 of the deflector 29. The deflector 29 deflects the gas upwardly, and out from its upper open end into the interior of the air-bag 34.

The gas, deflected upwardly by the deflector 29, inflates the minor part of the air-bag 34 which is within and above the deflector 29. The inflating part of the air-bag moves upwardly.

As the air-bag 34 is inflated, the expanding material of the air-bag 34 exerts an upward force on the lower side of the sheet 36, and also an upward force on the lower side of the door 37. This upward force causes the split line around the front and side edges of the sheet 36 to rupture, and the door 37 to pivot upwardly about its front edge, into the plenum chamber 12. The door 37 continues to pivot into the plenum chamber 12, until the upturned end 39 of the door 37 contacts the lower edge of the grille 5. The upward end 39 of the door 37 exerts an upward force on the grille 5, which pushes the grille 5 upwardly, and out from within the slot 4 in the dashboard 2. The door 37 continues to pivot, until the door 37 is stopped by the first reinforcing wall 13.

As the door 37 pivots, the main body of the sheet 36 also moves upwardly, into the plenum chamber 12, but the sheet 36 remains attached to the rear edge of the upper open end 17 of the U-shaped housing 16. The sheet 36 is pressed against the second reinforcing wall 14, by the air-bag 34 as the air-bag 34 inflates. The sheet 36 covers the apertures in the second reinforcing wall 14, which is in the form of a grille and stops the material of the air-bag 34 from extending into the apertures that constitute the grille, which might otherwise damage the material of the air-bag 34. The air-bag 34 can thus inflate out from the upper open end 17 of the U-shaped housing 16, and be guided upwardly through the plenum chamber 12 by the door 37 and the sheet 36.

The part of the air-bag 34 which is inflated first by the gas from the gas generator 24 is the part of the air-bag 34 which is folded and initially positioned directly above the gas deflector 29. During the initial stage of the inflation of the air-bag 34, this part of the air- bag 34 which was folded over the gas deflector 29 becomes fully inflated, and extends out from the slot 4. The part of the air-bag 34 which is folded between the second wall 32 of the gas deflector 29 and the second wall 23 of the U-shaped housing 16, defines a major part of the air-bag 34 which remains folded within the U-shaped housing 16. As gas continues to be injected into the air-bag 34 by the gas generator 24, the air-bag 34 inflates further, and the still folded part of the air-bag 34 unravels as it is pulled out of the rear side of the slot 4. This allows a greater proportion of the material of the air-bag 34 to be pulled out from the rear side of the slot 4 than the front side of the slot 4, which results in the air-bag 34 inflating rearwardly and in a direction which is towards an occupant of the vehicle.

The door 37 and the sheet 36 provide a smooth surface, against which the inflating air-bag 34 may slide. The sheet 36 protects the material of the air-bag 34 from sharp edges which may protrude from the edge of the slot 4 and the edges of the second reinforcing wall 14.

In this embodiment described with reference to Figures 1 and 2, the safety arrangement 1 incorporates a single door 37 and a sheet 36, but in other embodiments, the safety arrangement 1 may incorporate a plurality of doors.

Referring now to Figures 3 and 4, an alternative embodiment incorporates many of the same parts as the parts of the above described embodiment, and thus these parts will be referred to with the same reference numerals, and will not be re-described. In this alternative embodiment the first reinforcing wall 13 is short relative to the height of the wall 7 of the duct 6, and the second reinforcing waIl 14 is also short relative to the height of the wall 8 of the duct 6.

In this alternative embodiment a first door 40 and a second door 41 extend across the upper open end 17 of the U-shaped housing 16 of the air- bag unit 15, to seal the upper open end 17. The first door 40 is pivotally mounted to the front edge of the upper open end 17, and the first door 40 extends approximately half way across the width of the upper open end 17. The free end of the first door 40 has an offset downwardly deflected lip 42, which sits beneath a free end of the second door 41.

The second door 41 is pivotally mounted to the rear edge of the upper open end 17, and the second door 41 extends approximately halfway across the width of the upper open end 17, and engages the upper part of the lip 42, to form a seal. The second door 41 has an upwardly inclined section 43 which is angled upwardly from its free end, over the lip 42.

In the event that an accident occurs, the gas generator 24 is actuated to generate gas to inflate the air-bag 34. The air-bag 34 inflates upwardly, in a manner corresponding to that described with reference to Figure 2, and exerts an upward force on the lower side of the first door 40 and the lower side of the second door 41. This upward force on the doors 40, 41 causes the doors 40, 41 to pivot about their pivot edge upwardly into the plenum chamber 12. The doors 40, 41 move to an open position in which they engage the reinforcing walls 13 and 14. The inflating air-bag 34 applies an upward force to the grille 5, and the grille 5 is displaced upwardly into the cabin of the vehicle, to open the slot 4. The air-bag 34 is guided by the doors 40, 41 which contact the first reinforcing wall 13 and the second reinforcing wall 14. The air-bag 34 is thus allowed to inflate upwardly, into the cabin of the vehicle to protect an occupant of the vehicle.

Referring now to Figures 5 and 6, a further embodiment once again incorporates many of the same parts of the above described embodiments, and these parts will be referred to using the same reference numerals, and will not be re-described.

In this further embodiment the first side wall 20 and the second side wall 23 of the U-shaped housing 16 are differing heights to one another. The first side wall 20 extends above the upper edge of the second side wall 23, and the top section of the first side wall 20 forms the first side wall 7 of the air duct 6. The flange 18 which extends radially outwardly from the top of the first side wall 20 of the U-shaped housing 16 is mounted to the lower side of the dashboard 2, adjacent the front edge of the slot 4.

The rearmost wall 8 of the duct 6 is formed from a generally L-shaped reinforced wall 44. The L-shaped wall 44 has a radially outwardly directed mounting flange 45 at its upper end, and the mounting flange 45 is mounted to the lower side of the dashboard 2 and spaced from rear edge of the slot 4. The L-shaped wall 44 thus depends downwardly from the underneath of the dashboard 2, and the L-shaped section 44 curves forwardly to a lower mounting flange 46 which extends vertically downwardly from the forwardly curving part of the L-shaped wall 44. The lower mounting flange 46 is mounted to the second side wall 23 of the U- shaped housing 16 of the air-bag unit 15, so that the air-bag unit 15 is carried by part of the air duct 6.

In this further embodiment, a single door 47 is pivotally mounted to the rear edge of the upper open end 17 of the U-shaped housing 16. When the safety arrangement I is in an initial condition, the door 47 is inclined upwardly in a direction towards the front of the vehicle, and the door 47 has an upturned end 48 which contacts the first side wall 20 of the airbag unit 15. The door 47 seals the open upper end 17 of the air-bag unit 15, to prevent dirt and dust from the plenum chamber 12 from entering the interior of the air-bag unit 15.

in this further embodiment, the air-bag 34 is folded in a similar manner to that described above, and inflates in a similar manner. During the initial stages of inflation of the air-bag 34, the air-bag 34 exerts an upward force on the lower side of the door 47. The door 47 pivots in a clockwise direction, and the upturned end 48 of the door contacts the lower side of the grille 5, and displaces the grille 5 from the slot 4. The door 47 is prevented from pivoting further by the rear edge of the slot 4, and when the door 47 is in this position the door 47 provides a surface which guides the air-bag 34 upwardly and outwardly from the slot 4 as it inflates.

In the present Specification "comprises" means "includes or consists of' and "comprising" means "including or consisting of'.

The features disclosed in the foregoing description, or the following Claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS: I. A safety arrangement mounted in a motor vehicle, the safety

arrangement comprising an air duct that defines a plenum chamber positioned beneath a dashboard in the vehicle to supply air to the windscreen of the vehicle, at least part of the lower side of the plenum chamber carrying an air- bag unit, the air-bag unit containing an air-bag with substantially all of the air- bag being beneath the plenum chamber when the safety arrangement is in a normal condition, there being at least one moveable element which, in an initial position, divides at least part of the interior of the air-bag unit from the plenum chamber, the said at least one element being moveable on deployment of the air-bag from the initial position to a second position in which the air-bag may inflate upwardly into the plenum chamber and out from the plenum chamber into the interior of the vehicle.
2. A safety arrangement according to Claim 1, wherein there are a plurality of moveable elements which, in an initial position, divide at least part of the interior of the air-bag unit from the plenum chamber.
3. A safety arrangement according to Claim 2, wherein one of the said moveable elements is a flexible sheet.
4. A safety arrangement according to Claim 3, wherein the said flexible sheet forms a substantially gas tight seal, which seals the interior of the air-bag unit housing from the plenum chamber.
5. A safety arrangement according to any one of the preceding Claims, wherein the said at least one movable element is a door which is pivotally mounted.
6. A safety arrangement according to any one of the preceding Claims, wherein a slot is formed in a part of the dashboard which defines an upper wall of the plenum chamber, and when the safety arrangement is in a normal condition a grille is fitted within the said slot, and wherein upon deployment of the air-bag the grille is displaced from the slot so that the air-bag may inflate out from the plenum chamber, through the slot, and into the interior of the vehicle.
7. A safety arrangement according to any one of the preceding Claims, wherein there is at least one reinforcing wall, which provides a surface which the movable element may contact, on deployment of the air-bag.
8. A safety arrangement according to any one of the preceding Claims, wherein a gas generator is mounted to a side-wall of the air-bag unit housing, and a gas deflector is mounted within the housing of the air-bag unit, to direct gas from the gas generator to inflate the said air-bag in a direction substantially towards the moveable element.
9. A safety arrangement according to Claim 8, wherein when the safety arrangement is in a normal condition, a minor portion of the air-bag is folded and positioned above the said gas deflector, and a major portion of the air-bag is folded and positioned to one side of the said gas deflector, such that gas from the gas generator inflates the minor portion of the air-bag before the major portion of the air-bag.
10. A safety arrangement substantially as herein described with reference to and as shown in Figures 1 and 2 of the accompanying drawings.
11. A safety arrangement substantially as herein described with reference to and as shown in Figures 3 and 4 of the accompanying drawings.
12. A safety arrangement substantially as herein described with reference and as shown in Figures 5 and 6 of the accompanying drawings.
13. Any novel feature or combination of features disclosed herein.