Frontal airbag for vehicle occupants and airbag module

Abstract

A frontal airbag for vehicle occupants, especially a passenger airbag, includes a contact panel (26) facing the vehicle occupant (12). Inside the airbag plural tethers (38) and/or partitions (38) are arranged which in portions withhold the contact panel (26) in the inflated state of the airbag (10) and form at least one lateral bead (34) and plural central beads (36) which in cross-section are smaller than the lateral beads (34). Furthermore, an airbag module is presented.

Claims

1. A frontal airbag for vehicle occupants, comprising a contact panel (26) configured to face the vehicle occupant (12) in a fully deployed state of the airbag (10), wherein inside the airbag tensile means (38) which in portions withhold the contact panel (26) in the fully deployed state of the airbag (10) are arranged at the contact panel (26), wherein in the fully deployed state of the airbag (10), the airbag (10) is expanded to a maximum extent of the airbag (10), the tensile means (38) are extended to a maximum extent of the tensile means (38), and the tensile means (38) are arranged so that the contact panel (26) forms a lateral bead (34) on at least one of its two lateral edges (32) and forms plural central beads (36) which in cross-section are smaller than the at least one lateral bead (34) between the lateral edges (32), wherein the lateral bead(s) (34) extend substantially from a top to a bottom of the airbag (10), and whereby in the contact panel (26) there are lower surface tensions in the area of the central beads (36) as compared to the higher surface tensions in the lateral bead or the lateral beads (34).

2. The frontal airbag according to claim 1, wherein at least one constriction (42) formed by the tensile means (38) extends over an entire vertical height of the contact panel (26).

3. The frontal airbag according to claim 1, wherein at least some of the beads (34, 36) extend cylindrically substantially in the area of the contact panel (26).

4. The frontal airbag according to claim 1, wherein the at least one lateral bead (34) has a depth (T.sub.S) measured from a contact panel-side end of a corresponding tensile means (38) in the longitudinal vehicle direction (x) which is larger at least by the factor 1.25 than the depth (T.sub.M) of the central beads (36).

5. The frontal airbag according to claim 1, wherein the at least one lateral bead (34) has a maximum width (B.sub.S) measured horizontally and transversely to a longitudinal vehicle axis, said width being larger at least by the factor 1.5 than a maximum width (B.sub.M) of the central beads (36).

6. The frontal airbag according to claim 1, wherein at least several tensile means (38) comprise tethers.

7. The frontal airbag according to claim 1, wherein the airbag (10) has one single chamber to be inflated.

8. The frontal airbag according to claim 1, wherein at least some of the tensile means (38) are partitions for dividing the interior of the airbag into different chambers (60, 62).

9. The frontal airbag according to claim 8, wherein the chambers (60, 62) are configured so that, in the fully deployed state, they have different internal pressures.

10. The frontal airbag according to claim 9, wherein the internal pressure of at least one central chamber (62) is lower than the internal pressure of the at least one lateral chamber (60).

11. The frontal airbag according to claim 8, wherein the tensile means (38) are fastened to a rear panel (28) opposite to the contact panel (26).

12. The frontal airbag according to claim 11, wherein the rear panel (28) includes fastening holes (30) for fastening the airbag (10) to a side of a module housing (20) of an airbag module.

13. An airbag module comprising at least one inflator (22) and an airbag (10) according to claim 9, wherein the at least one inflator is connected to the interior of the airbag so that the chambers (60, 62) are inflated to different extents and have different internal pressures.

14. The airbag module according to claim 13, wherein at each of the lateral edges (32) the airbag (10) includes a lateral bead (34) having a lateral chamber (60) as well as plural central chambers (62) forming central beads (36) on the contact panel (26).

15. The airbag module according to claim 14, wherein in the fully deployed state the lateral chambers (60) have an internal pressure higher than that of the central chambers (62).

16. An airbag module comprising at least one inflator (22) and one airbag (10) according to claim 1, wherein the airbag (10) includes a rear panel (28) opposite to the contact panel (26), the rear panel (28) of the airbag (10) being fastened to a side of a module housing (20) of the airbag module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features and advantages of the invention will be evident from the following description and from the following drawings which are referred to and wherein:

(2) FIG. 1 shows a top view onto an inflated frontal airbag according to the invention as part of an airbag module according to the invention in the mounted and inflated state, and

(3) FIG. 2 shows a top view onto a second embodiment of the frontal airbag according to the invention and the airbag module according to the invention equally in the mounted and inflated state.

DESCRIPTION

(4) In FIG. 1 a frontal airbag 10, more exactly speaking a front passenger airbag is illustrated. The airbag 10 is shown in the mounted and completely inflated state. The longitudinal vehicle direction in the driving direction boars the coordinate x and the transverse vehicle direction in the horizontal direction bears the coordinate y. The occupant 12 is shown with his/her head 14 and his/her torso 16.

(5) The airbag 10 is part of an airbag module 18 comprising a module housing 20 and an inflator 22 accommodated in the module housing 20. In the folded state, the airbag 10 is accommodated in the module housing 20.

(6) It has to be emphasized that the inflator 22 may be a single-stage or multi-stage inflator comprising one or more exhaust openings spaced apart from each other. Alternatively, also plural inflators 22 are possible.

(7) The airbag 10 includes an outer wall 24 having plural portions, wherein the area facing the vehicle occupant 12 in the inflated state is referred to as contact panel 26. Moreover, there is a rear panel 28 opposite to the contact panel 16 which is fastened on the module side via fastening openings 30, for example.

(8) The inflator(s) 22 may be arranged inside the airbag 10 so that the rear panel is not located, as in FIG. 1, toward the occupant distant from the inflator, but is positioned, as shown by broken lines, inside the airbag module even if the airbag 10 is inflated.

(9) When the inflator 22 is disposed outside the airbag 10, the rear panel 28 has to include appropriate inflating openings, of course.

(10) As shown in FIG. 1, the airbag 10 has a shape widening toward the occupant, when viewed from the top.

(11) The contact panel 26 includes, when viewed from the occupant, two lateral edges 32 each of which has a lateral bead 34 extending toward the occupant i.e. against the driving direction x. The lateral beads 34 form the lateral ends of the contact panel 26. Between the lateral beads 34 the contact panel has plural central beads 36 being laterally delimited so-to-speak by the lateral beads 34.

(12) The contour of the contact panel 26 is obtained by tensile means 38 located inside the airbag 10 which are tethers in the embodiment shown in FIG. 1. Said tensile means 38 are fastened, on the one hand, to the contact panel 26 by their end close to the occupant and there result in a constriction 42 and, on the other hand, are fastened to the rear panel 28 at their opposite end.

(13) In the embodiment shown in FIG. 1, which is not meant to be limiting, two directly adjacent tensile means 38 are fastened in the area of the contact panel 26 distant from each other, but in the area of the rear panel 28 at the same fastening position so that they are diverging in V-shape toward the occupant when viewed from the top.

(14) The two lateral beads 34 and a transition to the directly adjacent central bead 36 are defined by the two laterally outer tensile means 38. By way of example, which is not meant to be limiting either, there is a central bead 36 between the outer central beads 36. However, there may as well be provided more than three central beads 36 or only two central beads 36, for example.

(15) It is clearly visible from FIG. 1 that the radii of the lateral beads 34 and the cross-sections thereof are larger than the radii and, resp., cross-sections of the central beads 36. The cross-section thereof is determined in a top view. The beads 34, 36 start from a line 40 extending substantially in the Y direction which passes through the point or points of contact of the assigned tensile means 38 with the contact panel 26. In the embodiment shown in FIG. 1, all of the connecting lines between the contact points are located on a line 40 which is a straight line, which need not absolutely be the case, however. The cross-sections A.sub.S of the lateral beads are in any case larger than the cross-sections of the central beads A.sub.M, wherein in FIG. 1 only one of the lateral beads 34 at a time and one of the central beads 36 at a time is denoted with A.sub.S or A.sub.M.

(16) The depth T.sub.S of the lateral beads 34 measured in the longitudinal vehicle direction X is larger by at least the factor 1.25, especially by at least the factor 1.5, than the respective maximum depth T.sub.M of the central beads 36. In this case, too, the depth is measured from the afore-explained line 40.

(17) The width, too, measured in the Y direction, namely the maximum width B.sub.S of the lateral beads 34 is definitely larger, namely at least by the factor 1.5, especially at least by the factor 1.75, than the maximum width B.sub.M of the central beads 36. When the widths or depths of the lateral beads 34 and of the central beads 38 are different, the indication refers to the smallest lateral bead 34 and the largest central bead 36.

(18) In the embodiment shown in FIG. 1, the airbag 10 has one single chamber to be inflated, for in the Z direction the tensile means 36 are so narrow that no different chambers having different pressures are formed in this way.

(19) It has to be emphasized that the shown tensile means 38 in the Z direction may also symbolize plural superimposed tensile means. The beads 34, 36 furthermore are optionally cylindrical at least over a portion or over the entire contact panel, which is not meant to ha limiting, however.

(20) The constrictions 42 formed by the tensile means 38, only one constriction of which is provided with the reference numeral 42 in FIG. 1 to maintain the survey, may extend over the entire vertical height of the contact panel 26 or may end ahead of the upper and/or the lower edge of the contact panel 26.

(21) Since, as explained before, only one single chamber to be inflated is present, the internal pressure is equal throughout after inflation of the airbag 10. Due to the different curvatures and different sizes of the beads 34, 36, in the area of the lateral beads 34 the contact panel has a greater surface tension than in the area of the central beads 36. This means that immersing in the area of the central beads 36 is easier than in the area of the lateral beads 34. Hence, in the case of angular impact, as compared to the lateral beads 34 the occupant will immerse more easily in the area of the central beads 36, which helps to stabilize the head against lateral rotation. However, the lateral beads 34 serve for imparting stability to the airbag 10 and, in addition, to exclude slipping off the contact panel 26.

(22) The embodiment according to FIG. 2 substantially corresponds to that shown in FIG. 1 so that hereinafter only the differences will be discussed and the previously used and introduced reference numerals are used for like or functionally like parts, areas or portions.

(23) In the embodiment according to FIG. 2, the tensile means 38 or at least some of the tensile means 38 are in the form of partitions so that plural chambers are resulting in the interior of the airbag 10. The lateral beads 34 are formed by a lateral chamber 60 in each case, the central beads are the end portions of central chambers 62 facing the occupant.

(24) Preferably, which is not meant to be limiting, each bead 34, 36 has its own chamber 60 or 62, i.e. one chamber is provided for each bead.

(25) The lateral chambers 60 are inflated, as compared to the central chambers 62, to a higher internal pressure than the central chambers 62. For this purpose, appropriate gas-conducting ducts may start from the gas generator or generators 22. Moreover, it is possible to provide different flow courses, for example the lateral chambers 60 could be inflated first, and the central chambers 82 then could be filled via overflow orifices 64 in the partitions.

(26) In this embodiment, too, the different internal pressures facilitate immersing into the central beads 36 and the respective central chambers 62 thereof, as compared to immersing into the lateral beads 34 and the corresponding lateral chambers 60 thereof.

(27) It is also evident in the embodiment according to FIG. 2 that the central one of the central beads 36 is defined by indentations 42 which are not on a line 40 extending in parallel to the direction Y. In this case, the cross-section A.sub.M and the depth T.sub.M are defined by a connecting line of the respective contact points of the adjacent partitions extending angularly relative to the direction Y with the contact panel 40.

(28) In this case, too, the portions of the contact panel 26 defining the lateral beads 34 exhibit higher surface tension than the portions of the contact panel 26 defining the central beads 36 by the higher internal pressure of the airbag in the lateral chambers 60.

(29) Instead of two lateral beads 34, the airbags 10 illustrated in FIGS. 1 and 2 may also be formed to have only one lateral bead, with the latter being located at the lateral edge which is close to the side window assigned to the occupant 12. Also, a variant would be imaginable in which the one lateral bead is arranged on the inner side so as to prevent slipping off toward the neighboring vehicle occupant.

(30) The outer wall of the airbag 10 preferably consists of fabric material and may have one or more cut parts.

(31) It is emphasized that the individual features need not necessarily be linked in the way shown in FIGS. 1 and 2 but that individual features representing preferred variants only may also be omitted. Just as well, features may be combined in the individual embodiments although they are not illustrated to be combined in the drawings.