BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages of the invention will be apparent from the following description of a preferred embodiment and from the enclosed drawings, to which reference is made, in which:
FIG. 1 shows a top view onto the gas bag of a gas bag module according to the invention;
FIG. 2 shows a sectional view along the line 2-2 of FIG. 1;
FIG. 3 shows a gas bag according to the invention in the unfolded state;
FIG. 4 shows the gas bag of FIG. 3 in the case of stress, and
FIG. 5 shows a gas bag module, with the discharge control element being provided in a frame part.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 schematically show the wall section of a component 10 with a discharge opening 12, which is circular here, which is closed at least partially by a plastic membrane 14, for example of silicone. The discharge opening 12 and the plastic membrane 14 are surrounded in a ring shape by a discharge control element 16 which contains a dilatant material 18. In the embodiment shown here, the dilatant material 18 is encased in the form of a tube by the plastic membrane 14. The discharge control element 16 is therefore introduced into the plastic membrane 14. The plastic membrane 14 is fastened at its edges lying opposite the discharge opening 12 to the wall of the component 10 by a seam connection or adhesive connection.
A gas bag 30 is shown in FIG. 3, which has been filled with gas from the gas generator of a gas bag module 28, illustrated diagrammatically, and in so doing has unfolded from the module. Independently of the blanks from which the gas bag 30 is formed, the wall of the gas bag 30 can be divided into a front wall section 20, which constitutes a primary impact surface for a vehicle occupant 22, and an opposite, rear wall section 24 and lateral wall sections 26 lying therebetween.
A discharge opening 12 with a discharge control element 16 of the type described above is provided in an upper region of the gas bag 30 in one of the lateral wall sections 26.
A further embodiment of the gas bag module according to the invention is illustrated in FIG. 5. This embodiment includes a gas generator 32 fixed to a carrier plate 34 of the gas bag module 28. The rims of the carrier plate 34 are bended up to form a frame part 36, which holds the gas bag 30 in a usual manner. The carrier plate 34 and the frame part 36 can be formed integrally with each other, as shown in FIG. 5. However, they can also be formed of separate components. A discharge opening 12 is formed in a wall section of the frame part 36 and is at least partially covered by the discharge control element 16. The discharge control element 16 can be formed as shown in FIGS. 1 and 2, and may be applied on the inner side of the wall section of the frame part 36. Further, it is possible that the discharge control element 16 with the dilatant material 18 contained therein is incorporated into the wall section of the frame part 36. Preferably, the discharge control element 16 is integrally formed with the wall section of the frame part 36. As an alternative to the embodiment shown in FIG. 5, the discharge control element 16 can be arranged on the outer side of the frame part 36. Finally, the discharge opening 12 together with the discharge control element 16 can also be arranged in the carrier plate 34 or in every other part of the gas bag module 28, for example in a module cover, which is however not shown.
The gas bag module illustrated in FIG. 5 is provided for being arranged in a vehicle steering wheel. Accordingly, the discharge control element 16 can also be placed in the steering wheel, wherein it is in fluid connection with the gas bag module.
In all embodiments, when the gas bag 30 is stressed by the impacting vehicle occupant 22, the internal pressure in the gas bag 30 rises considerably. The opening cross-section of the discharge opening 12 thereby increases. The size of the opening cross-section here is dependent on the intensity of the impact, which is affected inter alia by the weight of the vehicle occupant 22.
As the dilatant material 18 in the discharge control element 16 becomes harder as the stress increases, the opening cross-section of the discharge opening 12 is smaller with the impingement of a heavy vehicle occupant than with the impingement of a lighter vehicle occupant 22. Therefore, less gas can flow out from the gas bag per unit of time. This brings about the desired effect that the gas bag is harder with the impact of a heavy person or a greater impact impulse than with a light person or a smaller impact impulse. The heavy occupant is therefore prevented from penetrating onto the instrument panel, and light occupants are prevented from rebounding from a gas bag which is too hard and being thrown back.
Patent Application
20070284861
