DE29521695U1 - Airbag module - Google Patents

Description

PETRI AG

Berlin branch
Hadlichstrasse 19

13187 Berlin

PTR221

Airbag module

Description

The invention relates to an airbag module according to the preamble of claim 1.

Gasbag systems, in which a cushion is automatically inflated in front of the occupant in the event of a motor vehicle accident using a gas generator, are known for both the driver's seat and the passenger seat.

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The gas bag must be inflated in a short time to ensure that the occupant is safely protected in the event of a collision with the vehicle. In practice, inflation takes place within a few milliseconds. This ensures that the gas bag is already inflated in the event of a collision with the vehicle before the occupant is thrown towards the gas bag. This assumes that the occupant is in a normal position determined by the seats, so that the occupant does not touch the gas bag during inflation.

However, this normal case does not apply if the occupant is leaning forward during the impact of the vehicle and is usually located with his head within the space provided for the inflatable gas bag. The gas bag, which has been inflated in the above-mentioned short time, then hits the occupant, which can cause injuries.

To avoid this disadvantage, it is known from DE 42 27 559 A1 to inflate the gas bag in the direction of the occupant (axial direction) at a comparatively slow rate of expansion and in the sideways direction at a comparatively high rate of expansion. However, this device has the disadvantage that the gas bag may not yet be fully inflated in the axial direction if the occupant is thrown forwards during the impact, thereby injuring him.

Although on the one hand it should be avoided that the occupant touches the gas bag during its inflation, on the other hand it is desirable that the occupant, even if he is in a normal position during the impact, touches the gas bag as soon as possible after it has inflated.

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touches the passenger without endangering the passenger. This is not guaranteed in particular with the passenger airbag, as the gas bag inflates in directions other than the driver's direction. This results in the disadvantages that the distance between the inflated air bag and the passenger is relatively large and that the area of the gas bag that the passenger comes into contact with is reduced. This has an adverse effect on the surface pressure on the passenger.

The invention is therefore based on the object of creating an airbag module which, in the event of a vehicle impact, enables early contact between the gas bag and the occupant with reduced surface pressure.

According to the invention, this is achieved according to the characterizing part of claim 1.

In an airbag module, in particular for the passenger seat, with a gas bag and a gas generator, the airbag module according to the invention has at least one assembly to ensure a directed deployment of the gas bag in a predetermined main deployment direction, in particular in the direction of the vehicle occupant. With such an assembly, the gas bag achieves an increased surface expansion in the direction of the vehicle occupant. This is achieved at the expense of the expansion of the gas bag in directions, e.g. in the direction of the windshield, which are less effective for the occupant in the event of a vehicle impact.

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In one embodiment, the gas bag has at least one retaining strap in the area of attachment to the gas generator, which extends from the area of the gas generator essentially in the direction of the windshield of the motor vehicle. In particular, several retaining straps extend from the area of the gas generator approximately parallel or radially in the direction of the windshield of the motor vehicle. The retaining straps preferably extend in the direction of the lower area of the windshield. In this arrangement, the retaining straps ensure that the gas bag can only expand to a small extent in the direction of the windshield when inflated, while it can expand over a larger area in the direction of the occupant. This is possible without changing the shape of the gas bag, since the gas bag fabric has a high degree of stretchability, which can be up to 40%. By arranging the retaining straps in this area, the gas flow is diverted in the direction of the occupant.

In a further embodiment, a rotatable and/or movable cover cap is provided between the gas generator and the windshield, which is at least partially closed in the direction of the windshield and which is open in the working position in the direction of the gas generator and the occupant. In an embodiment particularly suitable for a passenger airbag module, the cover cap has a closed upper part in the direction of the windshield that is adapted to the top of the dashboard and that has approximately vertical side parts at its ends that run transversely to the direction of travel and to which the cover cap is rotatably attached. In addition, a stop is provided for limiting the range of rotation of the cover cap.

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pe is provided. The stop can be implemented in such a way that a circular slot and an immovable stop bolt engaging in this slot are provided in at least one side part.

In this embodiment, the gas escaping from the gas generator flows against the upper closed section of the cover cap and twists it to a stop so that the gas bag is inflated below the closed section in the direction of the occupant. As with the embodiment with safety straps, the expansion of the gas bag in the direction of the windshield is limited so that in this case too it can spread out over a larger area in the direction of the occupant.

In a modified embodiment, the cover cap has the shape of a ball game goal, with two essentially vertical slots being provided in each side wall, to which immovable guide and stop bolts are assigned. Preferably, the slots closer to the occupant extend further upwards than the slots further away from the occupant. This cover cap is lifted by the inflating gas bag after the gas generator is ignited, thus creating an opening for the gas bag in the direction of the occupant. The cover cap prevents the gas bag from spreading in the direction of the windshield.

In a further embodiment, a gas diffuser is provided above the gas generator for the outflow of the generator gas into the gas bag, whereby the diffuser has larger outflow openings in the desired main deployment direction of the gas bag compared to the other directions.

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This design also ensures that the gas bag inflates preferentially in the direction of the occupant.

The airbag module according to the invention can be operated with a commercially available gas bag that has a symmetrical contour. However, the preferred deployment of the gas bag can be further supported by the fact that it has an asymmetrical contour.

In a further embodiment, the gas bag consists of an upper part and a lower part, and is folded inwards on the side facing the occupant so that a pocket is formed. The upper part is also provided with tear seams in the area of the pocket. In this embodiment, the expansion of the gas bag in the uninflated state is shortened by folding in the upper and lower sides. During the inflation process, the volume formed by the lower part in the area of the pocket is inflated first, while the section formed by the upper part in the area of the pocket is prevented from unfolding by the tear seams. Instead of rising vertically, the gas bag is diverted towards the hips of the occupant. As soon as the gas bag is well filled and the fabric tension exceeds a certain level, the tear seams tear and the gas bag unfolds completely.

The invention will be explained in exemplary embodiments with reference to drawings. They show:

Fig. 1 the arrangement of an airbag module with a safety strap in a car;

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Fig. 2a-c an airbag module with several safety straps and asymmetric gas bag;

Fig. 3 an airbag module with approximately parallel retaining straps;

Fig' 4a-c an airbag module with a rotatably mounted cover cap;

Fig. 5a-c an airbag module with a movable cover cap;

Fig. 6a-c a gas diffuser arranged above the gas generator in two views and in section;

Fig. 7a, b a gas bag for a passenger airbag with controlled deployment in section and in plan view;

Fig. 8a-c Installation positions for passenger airbag modules.

Fig. 1 shows an airbag module for a passenger seat. The arrangement shown there in the car is referred to as "top-mounted". Arrangements of the passenger airbag module in the dashboard in front of the occupant are referred to as "mid-mounted" and in the direction of the footwell as "low-mounted".

On the airbag module, which is arranged below the dashboard 1, a catch strap 2 is provided in the area of the attachment of the gas bag 3 to the gas generator 4. The catch strap 2 extends in the gas bag from the area of the gas generator 4

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starting in the direction of the windshield 5 of the motor vehicle and prevents the gas bag from spreading further in the direction of the windshield 5 when it is inflated. The safety strap is intended to divert the gas flow in the direction of the occupant. The gas bag therefore spreads further in the direction of the vehicle occupant 6, i.e. although the gas bag is symmetrically constructed, it inflates asymmetrically in the direction of the vehicle occupant, particularly as a result of the safety strap. This increases the surface area of the gas bag against which the vehicle occupant is thrown in the event of a vehicle impact, so that the surface pressure on the occupant's body is reduced. This effect is further supported by the support on the windshield and the highly asymmetrical shape of the gas bag.

In the embodiment of Figures 2a to c, an airbag module is shown with several retaining straps 7, whereby in this case an asymmetrical gas bag 8 is used. In the resting position (Fig. 2a), the gas bag 8 is arranged in a fold around the gas generator 4. After the gas generator 4 is ignited, the gas bag is inflated in the direction of the windshield (not shown here) until the retaining straps 7 and the shape of the gas bag prevent further inflation in this direction (Fig. 2b). The further expansion then takes place, supported by the asymmetrical shape of the gas bag 8, in the direction of the vehicle occupant (not shown here) (Fig. 2c). The arrow in the gas bag 8 indicates the direction of expansion of the gas flow.

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In Fig. 3, which, like Fig. 2c, shows the gas bag in an almost inflated state, a section through a gas bag with an internal gas generator is shown. The retaining straps 9 are continuous straps that wrap around the gas generator and are sewn to the lower plate under the gas generator and at both ends to the upper plate.

In the embodiment of Figures 4a to 4c, a cover cap 12 is mounted in joints 13 provided in the side walls 14 of the housing above a tubular gas generator 10, which is arranged in a housing 11. The cover cap 12 has a closed upper part 15 and side parts 16. At least one side part is provided with a slot 17, which is assigned a stop bolt 18, which is fastened in the side wall 14. The cover cap 12 can be held in the rest position by fastening elements with a predetermined breaking function. It can be a screen integrated in the dashboard.

In the rest position shown in Fig. 4a, the

Upper part 15, which corresponds to the top of the

dashboard, the housing 11 at the top. The

Stop bolt 18 rests at the upper end of slot 17.

After the tubular gas generator 10 has been ignited, the cover cap 12 is rotated upwards by the inflating gas bag 3 until the stop bolt 18 rests against the lower end of the slot 17 (Fig. 4b). In this position, an opening is present between the housing 11 and the upper part 15 of the cover cap 12 pointing towards the vehicle occupant, through which the inflating gas bag can expand towards the occupant.

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a cap position the gas flow can be directed. This embodiment is particularly advantageous for a construction of the module towards the footwell ("low-mounted").

In the embodiment of Figures 5a-c, the housing 11 with the tubular gas generator 10 is covered by a cover cap 19, which is arranged so that it can be moved in the direction of the windshield and which has the shape of a ball game goal. It consists of an upper part 20, a rear part 21 and two side parts 22. The side parts 22 have slots 23, 24, to which stop bolts 25, 26 fastened in the housing 11 are assigned. As can be seen from the figures, the slots 24 are longer than the slots 23, so that the cover cap 19 has an inclined position in its rest position and the upper part 20 adapts to the contour of the dashboard. In the rest position, the stop bolts 25, 26 rest on the upper end of the slots 23, 24.

After ignition of the gas generator 10, the cover cap is pushed upwards by the inflating gas bag until the stop bolts 25, 26 rest against the lower ends of the slots 23, 24. In this position, an opening is present between the housing 11 and the upper part 20 of the cover cap 19, pointing in the direction of the vehicle occupant, through which the inflating gas bag 3 can expand towards the occupant. In Fig. 5b, the main direction of expansion of the gas flow is marked with an arrow, which corresponds to the main direction of deployment of the gas bag.

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In the embodiment of Figures 6a to 6c, a gas diffuser 27 is provided above the housing (not shown) with the tubular gas generator, through which the gas can flow out into the gas bag (not shown) after the gas generator is ignited. The gas diffuser 27 has outflow openings 28 and 29. The outflow openings 29 in the direction of the occupant, i.e. in the intended main deployment direction of the gas bag, are significantly larger than the outflow openings 28 in the opposite direction or transversely thereto. Figure 6a shows the gas diffuser 27 in a view in which the larger outflow openings 29 in the main deployment direction can be seen. Figure 6c shows a view of the gas diffuser 27 in which the smaller outflow openings 28 provided against the main deployment direction can be seen. Fig. 6b shows a central section through the diffuser 27. It can be seen that transverse to the main unfolding direction, only smaller outflow openings are also provided.

Figures 7a and 7b show another possibility of achieving controlled deployment of the gas bag. As can be seen from Fig. 7a, the side of the gas bag facing the occupant is folded inwards. The dot-dash line shows the outline of the air bag before folding. Folding shortens the extent of the gas bag in the uninflated state and in the folded area four layers of gas bag fabric lie on top of each other. In this way a pocket 32 is created between the upper part 3 0 and the lower part 31 of the gas bag. The upper part 3 0 is provided with tear seams 33 in the area of the pocket 32.

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In this embodiment, the unfolding process of the gas bag takes place in such a way that in the shortened gas bag section, the volume formed by the lower part 31 in the area of the pocket 32 is first filled with gas. The gas bag is forced to unfold intensively towards the occupant and downwards. Instead of rising vertically, the gas bag is deflected in an arc around the dashboard in the direction of the occupant's hips.

As soon as the gas bag is well filled and the fabric tension exceeds a certain level, the tear seams 33 tear and the gas bag unfolds completely.

The described embodiments ensure that the gas bag has an increased surface area in the direction of the vehicle occupant. This is achieved by reducing the expansion of the gas bag in directions, e.g. towards the windshield, which are less effective for the occupant when the vehicle impacts. By increasing the surface area of the gas bag relative to the vehicle occupant, the surface pressure when the occupant impacts the gas bag is further reduced.

Figures 8a to 8c show the various installation options for a passenger airbag module. Fig. 8a shows the airbag module 34 "top-mounted", Fig. 8b "mid-mounted" and Fig. 8c "low-mounted.

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Claims (13)

PTR221 Page 13 Claims 1. Airbag module, in particular for the front passenger seat, with a gas bag and a gas generator, characterized, that the airbag module has at least one assembly to ensure a directed deployment of the gasbag in a predetermined main deployment direction. 2. Airbag module according to claim 1, characterized in that the airbag module has at least one assembly to ensure a directed deployment of the gas bag in the direction of the vehicle occupant 3. Airbag module according to claim 1 or 2, characterized in that the gas bag (3, 8) has at least one retaining strap (2, 7, 9) in the region of attachment to the gas generator, which extends from the region of the gas generator (4) essentially in the direction of the windshield (5) of the motor vehicle. 4. Airbag module according to at least one of the preceding claims, characterized in that several retaining straps (7, 9) extend from the area of the gas generator - 14 - PTR221 Page 14 gate (4) extend approximately parallel or radially in the direction of the windshield (5) of the motor vehicle. 5. Airbag module according to at least one of the preceding claims, characterized in that the retaining straps (7, 9) extend in the direction of the lower region of the windshield (5). ■6. Airbag module according to at least one of the preceding claims, characterized in that a rotatable and/or displaceable cover cap (12, 19) is provided between the gas generator (4) and the windshield (5), which is at least partially closed in the direction of the windshield (5) and which is open in the direction of the gas generator (10) and the vehicle occupant (6). 7. Airbag module according to at least one of the preceding claims, characterized in that the cover cap in a passenger airbag module has a closed upper part (15, 20) adapted to the upper side of the dashboard in the direction of the windshield (5), which has approximately vertical side parts (16, 22) at its ends transverse to the direction of travel, to which the cover cap is rotatably attached, and that a stop is provided for limiting the rotation range of the cover cap. PTR221 Page 15 8. Airbag module according to claim 7, characterized in that a circular arc-shaped slot (17) and an immovable stop bolt (18) engaging in this slot are provided as a stop in at least one of the side parts (16). 9. Airbag module according to claim 7, characterized in that the cover cap (19) has the shape of a ball game goal, wherein in each side part (22) two substantially vertically extending slots (23, 24) are provided, to which immovable stop bolts (25, 26) are assigned. 10. Airbag module according to claim 9, characterized in that the slots (24) closer to the occupant extend further upwards than the slots (23) further away from the occupant. 11. Airbag module according to at least one of the preceding claims, characterized in that a gas diffuser (27) for the outflow of the generator gas into the gas bag (3, 8) is provided above the gas generator (10), the gas diffuser (27) having enlarged outflow openings (29) in the desired main deployment direction of the gas bag compared to the other directions. PTR221 Page 16 12. Airbag module according to at least one of the preceding claims, characterized in that the gas bag (8) has an asymmetrical contour. 13. Airbag module according to at least one of the preceding claims, characterized in that the gas bag consists of an upper part (30) and a lower part (31), that it is folded inwards on the side facing the occupant so that a pocket (32) is formed, and that furthermore the upper part is provided with tear seams (33) in the region of the pocket (32).