DE29724502U1 - Side airbag system for a motor vehicle - Google Patents

Description

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Side airbag system for a motor vehicle

The invention relates to a side airbag system for a motor vehicle with several airbags, in particular in an arrangement in which the airbags can be deployed essentially vertically downwards when activated.

Side airbag systems that are activated in the event of a crash and form a cushion between a vehicle occupant and the adjacent vehicle door or side wall are well known. They are usually located in the roof frame area and take up very little space when not activated.

Side protection devices of this type are known from US-PS 28 34 606 and US-PS 38 97 961. The first-mentioned document describes airbags arranged above each side window in the longitudinal direction of the vehicle, which are folded together in the initial state and which expand downwards to positions next to the feet of the vehicle occupant in the event of a crash. The subject of US-PS 38 97 961 are so-called inflatable side curtains which, when activated, extend from a roof frame area downwards to below the height of the parapet of the relevant side door. These curtains are divided into several airbags by vertical seams.

DE-OS 15 551 042 also describes an occupant side protection system with several inflatable protective elements attached to the upper edge of a window, which form a lateral safety wall in the event of a crash.

US-PS 49 66 388, on the other hand, deals with an airbag-equipped passenger side protection device which is housed in a vehicle door when inoperative and which, when activated, emerges upwards from a flap which then opens; by means of Velcro fasteners

It should then automatically hold itself to a roof frame area and to the vertical window pillars of the vehicle adjacent to the respective window. The expansion movement of the airbag from bottom to top is, however, disadvantageous in that the vehicle occupant often supports himself with one arm on an armrest or - particularly when the side window is open - on the door sill, so that the expansion path of the airbag is not clear.

In the side airbag systems listed above, the cushion formed by the airbags in the event of a crash takes on an undefined position and shape.

The subject of DE 43 07 175 A1 is an airbag-equipped occupant side protection system, which is formed from interconnected airbags which, when not activated, are housed at least partially in a roof frame area of the vehicle above a side window and, when activated, extend in front of the side window as a cover extending from the roof frame area. The airbags are arranged with their longitudinal axes essentially vertically and an airbag intended to cover the window pillar is connected to it via a guide in the manner of a roller guide, whereby the cover formed is fixed at one end in a horizontal direction. The airbags are each connected to an individual gas generator, so that this airbag-equipped occupant side protection system (side airbag system) has as many gas generators as it has airbags, whereby the activation of the gas generators can be triggered simultaneously or sequentially. When inflated, the airbags cover the area of the side wall of the motor vehicle near the head.

However, the solution is complex because the number of gas generators that have to be used is equal to the number of airbags. On the other hand, if the cushion is made up of a smaller number of airbags - in the extreme case of just one airbag - there is a risk that the cushion will be compressed too much in the event of a local impact in the potential occupant impact area because the gas can be displaced into the non-impacted areas, thus reducing the protective effect.

Furthermore, EP 0 685 366 A1 discloses a knee pad as knee impact protection with several airbags arranged next to each other and connected to each other, each of which is connected by a one-way valve to an upstream chamber that is connected to a gas generator. In the event of activation of the gas generator, the chambers

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and from there each airbag is filled with gas, whereby the gas pressure reached in the airbags corresponds to that in the chamber. If the gas pressure in an airbag exceeds the pressure in the chamber due to compression of the airbag as a result of an impact by the vehicle occupant, the relevant valve closes and the gas can no longer escape from the airbag. The arrangement of several airbags connected in this way to an upstream chamber results in a reinforcement of the knee pad and better knee impact protection, since the gas is blown into smaller chambers and can escape far less from a local impact point than in a single larger airbag.

It is an object of the invention to provide a side airbag system for a motor vehicle according to the preamble of claim 1, in which a single side wall airbag or several airbags can be filled with simple means to achieve a better protective effect with reduced effort.

This object is achieved with a side airbag system according to the features of claim 1. Advantageous embodiments are presented in the respective subclaims.

The side airbag system according to claim 1 has one or more airbags arranged next to one another in a roof frame area of a motor vehicle above a side window and housed there in a folded manner in the deactivated state, which airbags extend in front of the side window as a cover extending from this area in the activated state. According to the invention, the airbags are each connected via a valve directly to a gas guide channel that can be inflated by at least one gas generator, which is arranged in the roof frame and window pillar area and which is filled with gas in the event of a crash, wherein the valves are connected to an electronic control unit and can be controlled independently of one another by this.

It is advantageous to inflate the gas duct by two gas generators or by means of a stage generator simultaneously or at different times, as this increases reliability, particularly in conjunction with the controlled filling of the individual airbags, and gas of sufficient pressure is available at each airbag immediately after the gas generators are triggered.

This arrangement has the advantage that the number of gas generators required to inflate the airbags is limited to one or two, while still achieving optimum protection by allowing the airbags to be inflated in the order appropriate to the situation, i.e. depending on the seating position of the vehicle occupant in the event of a crash or the course of the collision. This means that the airbag(s) that will first impact with a part of the occupant's body, in particular the head, can be inflated with priority. This means that the entire amount of gas generated by the gas generators is available for the airbag(s) to be inflated first, which speeds up their inflation. Once gas has been blown into an airbag, it can no longer escape because the valve associated with it closes opposite the gas duct when the pressure in the airbag increases as a result of external pressure, and the gas remains in the airbag at increased pressure and can only be displaced to a limited extent due to the limited size of the airbag.

The valves are controlled via an electronic control unit depending on signals from appropriately arranged sensors. Since such a control is generally known to the person skilled in the art and is not the subject of the invention, it will not be discussed in more detail.

The valves can be pilot-controlled check valves, the opening - or closing - of which can be prevented and thus delayed by a pilot control.

The control of the valves depending on the type of accident is also of particular importance. If, for example, a vehicle rollover is detected by a suitably designed sensor system, filling takes place in such a way that relatively long service lives are achieved and, in addition, the specifically inflated chambers can contribute to energy absorption against occupant impact forces. In order to set predetermined filling characteristics, in a preferred embodiment, flow guide bodies, for example in the form of a ramp or scoop, are arranged within the gas guide channel; these can also be electronically controlled with regard to their angle of attack and/or flow cross-sections.

The airbags are advantageously designed to be connected, with adjacent airbags having a common wall, so that a closed cover is created between the vehicle occupant and the respective side window area. This would therefore be

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a multi-chamber side wall airbag. This cover can be designed as a padding of the same or different thickness at any point, namely when all airbags are filled with gas, or only a predetermined area of this cover can be inflated to form a padding depending on the position of the vehicle occupant. This cover, which is connected when activated, can be arranged in a defined position in a known manner (DE 43 07 175 A1).

It is also useful if the airbags are aligned with their longitudinal axis essentially vertically when inflated and if an airbag arranged in front of the window pillar is connected to it via a guide in the form of a roller guide. This means that the cover is already locked to the window pillar adjacent to the occupant during the activation process and is secured against horizontal movements parallel to the plane of the window. A cover with vertical alignment of the airbags is also easier to implement than a cover with a different alignment of the airbags, since the vehicles are equipped with other safety devices (e.g. seat belts) in the window pillar area that make a different arrangement and, above all, deployment more difficult.

The side airbag system according to the invention can be designed in such a way that the gas guide channel is installed in the roof frame area and is already present in the deactivated state. Such a gas guide channel facilitates the valve arrangement and valve control and increases the reliability of the overall system. However, the gas guide channel can also be an airbag arranged transversely to the airbags forming the cover and unfolding vertically, which is only inflated when the gas generators are triggered.

The airbags can also be designed in such a way that they have projections for covering holding and operating elements arranged on the roof frame or window pillar area and protruding into the vehicle interior in order to reduce the risk of injury. The individual connected airbags can also have different shapes. This development can also be used as an independent solution on a single-chamber airbag.

In the solution variant according to claim 7, protruding holding or operating elements such as handles, coat hooks, belt deflection fittings or the like are specifically supported by a - for example, bead-shaped - element incorporated in the airbag.

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The volume of the airbag is therefore only increased where it is absolutely necessary for safety reasons. Overall, this means that acceptable safety standards can be achieved with relatively small filling volumes.

The invention is explained below using an embodiment. The accompanying drawing shows schematically:

Fig.1 shows an activated side airbag system according to the invention in the side window area of a passenger car,

Fig.2 this side airbag system in section (ll-ll) and

Fig.3 this side airbag system in the deactivated state in section ll-ll.

Fig. 1 shows a side airbag system according to the invention arranged and inflated in the roof frame and window pillar area 1 of a passenger car above a side window 2. This consists of five airbags 3a to 3e arranged next to one another, which are preferably designed together in such a way that, for example, a bracing can be created between at least two vertical pillars of the vehicle body, with adjacent airbags, for example 3a and 3b or 3d and 3e, having a common side wall 4. The airbags 3a to 3e are arranged on a gas guide channel 5 formed firmly in the roof frame and window pillar area 1 and are each connected to this via a check valve 6. A gas generator 7 is arranged at both ends of the gas guide channel 5. However, an attachment 10 is also conceivable on all airbags 3a - 3e, so that the totality of all attachments, which can also form a common chamber when inflated, cover the entire roof frame area. The airbags 3a to 3e are vertically aligned in the inflated state shown. The airbag 3a inflated in the area of the window pillar 8 is guided on this via rollers 9 arranged in a vertical guide groove 8a or, for example, via ropes/straps (not shown) and is thus fixed in the horizontal direction. Here, two of the airbags (3c and 3d) are provided with attachments 10 for covering the handle 11 arranged on the roof frame 1a and shown in dashed lines, as can be seen in particular from the section ll-ll of Fig.1 shown in Fig.2. In a particularly advantageous development of the invention, the check valves 6 are connected to an electronic control unit 12 and can be controlled independently of one another by this. With

In Figure 1, dashed lines indicate a retaining strap 15 which acts as a guide for orienting the airbag deployment along the window panes/side wall of the vehicle.

Fig. 3 shows the side airbag system in section (ll-ll) in the deactivated state. The predetermined breaking point 13a of the panel 13 is formed on the bead 14 arranged on the roof frame 1a.

In the event of a side impact, the two gas generators 7 are ignited and blow into the gas channel 5 from both sides so that the same gas pressure is applied to each non-return valve 6. At the same time, the position of the occupant is signaled by corresponding sensors (not shown) and, if the occupant is in the normal sitting position, the non-return valves of the airbags 3d and 3e are opened with a delay and the airbags 3a to 3c are inflated more quickly because the entire amount of gas is initially available for them. If the gas pressure in the respective inflated airbag 3a to 3c reaches the gas pressure prevailing in the gas channel 5, the respective non-return valve 6 closes and the gas in this airbag can no longer escape, even if, for example, the vehicle occupant's head hits the airbag. This provides a stable and, due to the fixation of the airbag 3a to the window pillar 8, also defined fixed cover for the side window area of the passenger car. The occupant is effectively restrained and protected from injury through targeted energy conversion. If the occupant is out of position, other airbags, such as airbags 3c to 3e, are inflated preferentially (Fig. 1).

Instead of the gas generators described here, so-called stage generators can also be used, the individual ignition stages of which and the gas volumes released therein can be influenced by the electronic control unit 12 in accordance with the respective accident event with regard to the temporal sequence and setting of certain filling characteristics.

Claims (7)

1. Side airbag system for a motor vehicle with one or more airbags arranged next to one another in a roof frame and/or window pillar area of the motor vehicle above a side window and housed there folded together in the deactivated state, which airbag or airbags extend in front of the side window as a cover extending from the roof frame area in the activated state, characterized in that individual chambers of the airbag ( 3 ) or the airbags ( 3a to 3e ) are each connected via a valve ( 6 ) directly to a gas guide channel ( 5 ) arranged in the roof frame and window pillar area ( 1 ) and inflatable by at least one gas generator ( 7 ) and can be filled with gas, and that the valves ( 6 ; 6.1 , 6.2 ) are connected to an electronic control unit ( 12 ) and can be controlled independently of one another by the latter. 2. Side airbag system according to claim 1, characterized in that the gas guide channel ( 5 ) has a gas generator ( 7 ) at both ends and can be inflated from both ends at the same time. 3. Side airbag system according to claim 1 or claim 2, characterized in that the airbags ( 3 a to 3 e) are designed to be connected and adjacent airbags have a common wall ( 4 ). 4. Side airbag system according to one of claims 1 to 3, characterized in that the airbag or airbags ( 3 a to 3 e) are aligned substantially vertically in the inflated state and an airbag ( 3 a) arranged in front of the window pillar ( 8 ) is connected to the latter via a guide ( 8 a) in the manner of a roller guide ( 8 a; 9 ), cable guide or retaining strap guide ( 15 ). 5. Side airbag system according to one of claims 1 to 4, characterized in that the valves ( 6 ; 6.1 , 6.2 ) are pilot-controlled check valves. 6. Side airbag system according to one of claims 1 to 5, characterized in that the gas guide channel ( 5 ) is fixedly arranged in the roof frame and window pillar area ( 1 ). 7. Side airbag system according to one of claims 1 to 6, characterized in that the airbag ( 3 ) or predetermined airbags ( 3c , 3d ) have at least one projection ( 10 ) for covering the roof frame area or holding and operating elements ( 11 ) arranged on the roof frame or window pillar area ( 1 ) and projecting into the vehicle interior, and that the at least one projection ( 10 ) in the activated state runs at a distance from the roof frame and/or window pillar area ( 1 ) having the holding and operating element ( 1 ).