DE102008063111A1 - Method for controlling ventilation unit of restraining device, particularly gas bag with inflator unit, involves opening ventilation unit after switching time for releasing inflator unit - Google Patents

Abstract

The method involves opening a ventilation unit after a switching time for releasing the inflator unit. The switching time is determined as a function of parameters relevant to passenger occupancy. The parameters relevant to passenger occupancy comprise a passenger forward displacement. The parameters relevant to passenger occupancy comprise a passenger position or a seat position or a distance of the passenger from the gas bag or weight of the passenger.

Description

The The invention relates to a method for controlling a venting device a restraint device, in particular a gas bag with gas generator according to the preamble of claim 1.

airbags in cars are usually with a fixed inflation rate unfolded, and subsequently emptied by the porosity of the airbag and through provided vents depending on the momentum of the airbag impacting Vehicle occupants. Such systems do not allow adjustment of the retention effect the airbag to different serious accidents. To one To allow such adaptation are airbags with controllable Ventilation known. The ventilation devices can be easily switchable or a trained have continuous flow control.

From the DE 10 2004 057 064 A1 a method for driving a ventilation device of a vehicle airbag with gas generator is known, wherein the venting device is opened a switching time after triggering of the gas generator. The switching time is influenced by occupant relevant parameters. Influencing is essentially done by occupant position, weight, severity, severity and temperature.

Such Procedures do not take into account that the occupant position in the accident already in the few milliseconds to the release of the Airbags changed as the occupant by the delay the vehicle moves forward.

It is therefore an object of the present invention, a method according to to develop the preamble of claim 1 so that the position of the occupant before the accident and position changes be taken into account in the accident can and the retention effect of the restraint can be adjusted accordingly.

These The object is achieved by a method having the features of the patent claim 1 solved.

One Such method for driving a venting device a restraint device, in particular a gas bag with gas generator, based on the venting device after a switching time after a triggering of the gas generator open, with the switching time t depending on Occupant load relevant parameters is determined. According to the invention provided that the occupant relevant parameters a occupant forward include. The procedure fits the retention effect of Retaining device thus to the change in position of the occupant, which is caused only by the accident. The Retention effect is thus opposite to the state the technique known method improved.

About that In addition, the occupant load relevant parameters an occupant position and / or a seating position and / or a Include distance of the occupant to the airbag and / or occupant weight. This is a particularly precise adjustment of the retention effect to the individual circumstances for each Accident specific, allows. The occupant forwarding is preferably determined by a webbing extension. This allows a particularly simple and robust detection the change of occupant position in the course of the accident. For the detection one is directly influenced by the seat occupant Parameter, namely the Gurtbandauszug, used, so that a particularly precise detection compared to merely indirect Detection method is possible.

alternative is it possible to move the passenger forward over to determine a twofold integration of an acceleration signal. Such an acceleration signal is from the crash sensor of the restraint device delivered anyway. Compared to a direct detection is however accuracy is lost.

In Another embodiment of the invention is a gas generator used with two stages, wherein the switching time t a minimum time after ignition of the first stage does not fall below. This ensures that a minimum threshold of retention effect the restraint device is not fallen below.

alternative can be provided that the case of a two-stage gas generator Switching time t a minimum time to ignite the second stage does not fall below, so first and second stage before opening the Absträuöffnung be ignited. Also so a minimum retention effect is ensured, with the selection of the specific minimum time and the choice between setting the minimum time after the first or the second stage of the concrete Embodiment of the gas generator and each of the Levels produced gas quantities depends.

Furthermore, it can be provided that the venting device is opened only after activating a switchable Gurtkraftbegrenzers. This improves the coordination between the switchable belt force limiter and the restraint. The switchable belt force limiter has a high force level until the occupant has moved so far in the crash that the airbag can develop its maximum retention effect. Then, the restraining effect of the airbag is further modulated by the switchable discharge opening.

In a further embodiment of the invention is provided that the venting device immediately after ignition of the gas generator is opened, if a predetermined The minimum distance between a seat and the gas bag falls below becomes. This can be at a particularly short distance between seat occupants and gas bag ensure that the unfolding of the Airbag softer than normal, so that development-related Injuries to the occupant are avoided.

Farther it can be provided that the venting device directly after ignition of the gas generator and before activation the switchable Gurtbegrenzers is opened, if a predetermined The minimum distance between a seat and the gas bag falls below becomes. Again, injury to the occupant is due to the unfolding gas bag avoided at particularly short distances.

In Another embodiment of the invention is the switching time increased by a predetermined amount, if the occupant not belted. The retention effect of the restraint device is thus increased to the lack of retention effect to compensate for the belt.

Farther can the occupant load relevant parameters the crash severity, include the course of the accident and the type of accident. Overall, so are outer Parameters, such as the delay, the specific nature of the Accident with internal parameters such as occupant position and sitting position and the like combined. For example, this results in a high vehicle deceleration and thus faster forward displacement the occupant a short switching time, with low vehicle deceleration and a concomitant slow advancement a longer one Switching time, with sitting or occupant position in front a short and in sitting position or occupant position behind a longer Switching time. For every combination of accident history and Occupant or seat position, possibly still occupant weight, So optimal intermediate values for the switching time be determined.

in the Following is the invention and its embodiments will be explained in more detail with reference to the drawing. in this connection demonstrate:

1 a flowchart for an embodiment of a method according to the invention;

2 a flowchart for an alternative embodiment of a method according to the invention with consideration of seating position and multi-stage gas generator;

three a flowchart of an alternative embodiment of a method according to the invention, taking into account the sitting position with triggering after the first stage of a multi-stage gas generator;

4 a flowchart of an alternative embodiment of a method according to the invention without consideration of the gas generator ignition;

5 a flowchart of an alternative embodiment of a method according to the invention with adaptation of the switching times to other parameters;

6 a flowchart of an alternative embodiment of a method according to the invention without consideration of seating position and gas generator triggering;

7 a flowchart of an alternative embodiment of a method according to the invention with additional control of a switchable belt force limiter;

8th a flowchart of an embodiment of a method according to the invention without consideration of the gas generator release when using a switchable belt force limiter,

9 a flowchart of an embodiment of a method according to the invention in which different threshold values depending on the information of a seat position sensor are used.

In a first functional block B10 of the in 1 The method is continuously queried a crash sensor of a motor vehicle. As long as the crash sensor does not detect a crash, the occupant advance IVV is set to zero by definition. The function block B10 is common to all illustrated embodiments of the method according to the invention and therefore should only be described with reference to FIG 1 to be discussed. The continuous zeroing of the occupant forward displacement ensures that offset errors of the acceleration sensor are not integrated and thus do not lead to a distortion of the predicted occupant advance IVV.

If the crash sensor detects an accident in function block B10, then a theoretical occupant advance IVV in method step S10 determined by double integration via the acceleration measured by the crash sensor. In the following method step S12, a buckle sensor GSS is interrogated so as to determine whether the seat occupant is strapped. If this is the case, step S14 is checked whether the occupant forward displacement exceeds a first threshold value S1. If this is the case, the switchable outlet opening is opened in step S16 in order to vent the airbag in this way. If this is not the case, the method returns to the function block B10, calculated in the sequence in step S10 a new occupant forward displacement and in turn undergoes the Gurtschlussschlussprüfung. If the occupant is not wearing a seat belt, instead of the method step S14, the method step S18 is performed and it is checked whether the occupant forward displacement IVV exceeds a second threshold value S2. The threshold values S1 and S2 can be adapted in such a way that the restraining effect of the airbag is optimized to the particular state of seat occupant seatbelt. When the threshold value S2 is exceeded, in turn the switchable outflow opening is opened in step S16. If the threshold value S2 is not exceeded, the method returns to the function block B10, as in the case of the belted state of the occupant, and updates the occupant forward displacement. The loop shown is thus run through until the respective threshold for the belted or unbelted state of the seat occupant is reached and the switchable discharge opening of the airbag is opened.

2 represents an alternative embodiment of the method. Again, the function block B10 is run through and the occupant forward displacement is set to zero until the crash sensor detects a crash. Here again, in method step S10, the theoretical occupant advance IVV is calculated from double integration of the measured acceleration or deceleration. Unlike in 1 In an additional method step S20, a seat position sensor SPS is interrogated here. This determines whether the vehicle seat is in a forward position. In addition to the query of the seat position sensor SPS turn the belt buckle sensor GSS is queried in step S12 or S12 '. Thus, the method distinguishes between four states: seat in front, belted on the occupant; Seat in front occupant not wearing a seatbelt; Rear seat, passenger seat belt, rear seat, occupant not wearing a seat belt. Depending on the combination present, it is checked in method block B12 whether the occupant forward displacement IVV exceeds a threshold S1, S2, S3, S4 assigned to the respective combination. If this is not the case, then the method returns as already at 1 portrayed back to function block B10. If the respective threshold value is exceeded, an additional query is made in function block B14 before triggering the switchable outflow device as to whether the second gas generator stage has already ignited. Only after igniting the second gas generator stage, the switchable discharge opening is opened. If the ignition has not yet taken place, the method returns to function block B10 and traverses the loop until both the occupant forward displacement has exceeded the respective threshold value S1 to S4 and the second gas generator stage has ignited.

In the three illustrated embodiment of the method corresponds to in 2 shown. The two methods differ only in function block B14 or B14 '. While in 2 the triggering of the switchable outflow opening is made dependent on the ignition of the second stage of a multi-stage gas generator is described in the in three In the embodiment shown, the triggering of the switchable discharge opening is made dependent on the ignition of the first stage of a multi-stage gas generator.

The Threshold values S1 to S4 have different values in the event of a slight crash, if only one gas generator stage is ignited.

This in 4 embodiment shown corresponds to the two previously discussed. The procedure differs only in that the function block B14 or B14 'completely eliminated. So there is no query whether the gas generator has ignited. The outflow opening can thus be opened early to already make the inflation of the airbag less hard. This may be conducive to particularly mild accident events or significant out-of-position situations of the occupant. In the 5 shown embodiment of the method corresponds to in 1 shown. The query of the buckle switch GSS in step S20 and the verification of the thresholds S1 and S2 in steps S14 and S18 is supplemented here only by the function block B14. It is therefore additionally checked whether the gas generator has already triggered. Only after triggering of the gas generator, the switchable outlet opening is then opened in the method step. This can be ensured that a predetermined Minderrückhaltewirkung is guaranteed. Furthermore, an adaptation of the threshold values S1 and S2 can take place-which is not shown in the flowchart. The adaptation can be carried out as a function of the crash course, the crash type, (full or partial coverage or oblique crash) of the vehicle acceleration, the vehicle speed, the time from the beginning of the crash, the seat longitudinal position, the occupant position and other load-related parameters.

In the 6 shown embodiment ent again speaks the in 5 shown. Again, the thresholds S1 and S2 are dynamically changed depending on the mentioned parameters. The function block B14, which includes a query of the triggering of the gas generator, is omitted in the 6 shown embodiment, so that the switchable outflow openings can be opened in step S16 regardless of the state of the airbag, so as to ensure, for example, a particularly soft deployment of the airbag in light crash events.

7 shows the flowchart of an embodiment of the method, which is essentially the in 5 shown corresponds. The triggering of the switchable discharge opening, however, is made in function block B14 'not by the ignition of the first stage, but by the ignition of the second stage of the gas generator dependent. Another difference can be found in method step S20. If it is determined during the check of the buckle sensor that the occupant is strapped, the process branches. In parallel to the check in step S18 whether the occupant forward IVV exceeds the second threshold S2, the function block B16 is executed. Here it is checked whether the occupant forward IVV exceeds a third threshold S3. If this is the case, then in addition to a possible triggering of the switchable discharge opening in step S16, a switchable belt limiter is activated. Release of the switchable Gurtkraftbegrenzers can additionally be done only after the ignition of a belt tensioner. This allows a particularly good coordination of the restraining behavior of the belt and airbag.

This in 8th The method shown corresponds again to the in 7 shown. Again, a function block B16 is present in which is checked with buckled seat occupant, whether the occupant forward IVV exceeds a third threshold, in which case a switchable Gurtkraftbegrenzer is activated.

Im in 9 shown embodiment is analogous to 2 queried a seat position sensor and determined whether the vehicle seat is in a forward position. Depending on this, the process branches into two alternative function blocks B20 and B22. The two function blocks B20 and B22 correspond to those in 7 shown embodiment, starting with the local step S20. Depending on the information of the seat position sensor, however, different threshold values for the occupant forward displacement are used in order to integrate the information of the seat position sensor and to determine optimum switching times depending on the seat position.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 102004057064 A1 [0003]

Claims (11)

Method for controlling a venting device of a restraint device, in particular a gas bag with a gas generator, wherein the venting device is opened after a switching time after a triggering of the gas generator, wherein the switching time t is determined in dependence on occupant load relevant parameters, characterized in that the occupant load relevant parameters include occupant forward displacement , Method according to claim 1, characterized in that that the occupant relevant parameters an occupant position and / or a seating position and / or a distance of the occupant to the airbag and / or occupant weight. Method according to claim 1 or 2, characterized that the occupant forwarding via a belt extension is determined. Method according to claim 1 or 2, characterized that inmates advance over a dual integration an acceleration signal is determined. Method according to one of claims 1 to 4, characterized in that a gas generator with two stages is used, wherein the switching time t a minimum time after a Ignition of the first stage does not fall below. Method according to one of claims 1 to 4, characterized in that a gas generator with two stages is used, wherein the switching time t a minimum time after a Igniting the second stage does not fall below. Method according to one of claims 1 to 4, characterized in that the venting device only opened after activating a switchable belt force limiter becomes. Method according to one of claims 1 to 4, characterized in that the venting device opened immediately after the ignition of the gas generator is, if a given minimum distance between a seat or occupants and the gas bag is fallen below. Method according to one of claims 1 to 4, characterized in that the venting device immediately after ignition of the gas generator and before the Activating the switchable belt force limiter opened is, if a given minimum distance between a seat or occupant and the gas bag is fallen below. Method according to one of claims 1 to 4, characterized in that the switching time by a predetermined Amount increased or not delivered if the occupant not belted. Method according to one of claims 1 to 10, characterized in that the occupant load relevant parameters the crash severity, the course of the accident and the type of accident.