DE102010054743A1 - Safety device for use in motor vehicle, comprises vehicle seat, gas cushion in form of rebound airbag and rebound airbag blowing control device, which is connected with crash sensor for detection of event of accident - Google Patents

Abstract

The safety device comprises a vehicle seat, a gas cushion in the form of a rebound airbag and a rebound airbag blowing control device, which is connected with a crash sensor for detection of an event of accident. The vehicle seat is a front seat (2), whose back rest (6) is movable backwards into a lying position as idle position for a seat user (7). The lying position is detected by a lying position sensor (26).

Description

The invention relates to a safety device in a motor vehicle according to the preamble of claim 1.

In a front-end crash of a motor vehicle, occupants on the vehicle seats are displaced forward by inertial forces. In order to minimize the risk of injury, safety devices in the form of restraints with belt systems and inflatable air bags are generally known as airbags.

After a frontal impact, in particular, the upper body of a seat occupant is rotated forward in an applied restraint device and caught in a deployed front airbag. Then there is a rebound, in which the upper body rotates back, with different rebound movements between the upper body and head can lead to so-called whiplash injuries.

In order to absorb such a rebound energy-absorbing, vehicle seats are already known in which controlled from a backrest and / or a headrest out of the gas bags as so-called rebound airbags are triggered and inflated. A rebound airbag trigger control unit is connected to at least one crash sensor for detecting an accident and ignites a rebound airbag in the presence of a crash signal.

Specifically, a generic safety device with a vehicle seat with a rebound airbag in conjunction with a three-point belt restraint system ( DE 695 17 432 T2 ) and with an additional front panel passenger side airbag ( JP 131 46 45 A1 ) known. In the case of the vehicle seats shown here, in each case a relatively small-volume rebound airbag is triggered on a vehicle seat in the sitting position with a largely vertical backrest. The resulting rebound forces and rebound energies are relatively low because of the low rebound travel up to the upright backrest and the triggering and shape of this Reboundairbags must be tailored to these conditions.

The object of the invention is in contrast to develop a generic safety device for use in a reclining position of a seat occupant.

This object is achieved in that the vehicle seat is a passenger seat, the backrest is pivoted to the rear in a reclining position as a rest position while driving for a seat occupant. Such a reclining position is detected by a reclining position sensor and a corresponding reclining position signal is supplied to the rebound airbag deployment control unit where it is implemented as a triggering condition for the rebound airbag.

In other words, the rebound airbag is only "armed" when the reclined position of the backrest is detected. An upright seating position of the backrest ensures that the rebound airbag is never triggered. This is essential, since especially in a frontal impact, a passenger in lying position performs a wide rotation with his upper body forward. However, in order to noticeably reduce the rebound travel for energy absorbing support, at least one or more relatively large volume rebound airbags are required. Ignition of such Reboundairbags with upright Lehnenstellung in the sitting position of a passenger would be a security risk and not tunable with the other elements of the safety device.

As a reclining position sensor, a rotation angle sensor can be mounted on the backrest pivot axis, which detects the pivot angle continuously, wherein from a certain pivot angle, a reclining position signal is generated as a trigger condition for the control. Such a lying position signal can be generated in concrete circumstances with a leaning angle relative to the vertical of greater than 35 °, preferably at 40 °. Alternatively, a limit switch for a corresponding backrest inclination for delivering a reclining position signal can be used.

In a preferred embodiment, the safety device further comprises a gas bag inflatable from a dash panel as a front airbag and passenger airbag, as is standard equipment in all modern motor vehicles. Such a front airbag is associated with a connected to the at least one crash sensor front airbag release control device with which is ignited at a detected crash or pre-crash situation, especially in a frontal crash situation of the front airbag to a predetermined front airbag ignition timing. On the other hand, the rebound airbag deployment control unit fires the rebound airbag with an ignition timing offset later on when the reclined position is detected. The ignition timing offset is chosen so that a front upper body position of a seat occupant is already reached in the rotation phase and the ignition occurs approximately at the beginning of the reverse rotation. In experiments, an ignition timing offset from the front airbag ignition of about 80 to 150 ms, preferably of 105 ms has been found to be suitable.

Since the upper body of a seat occupant in the lying position is relatively far away from a front airbag, an improved ignition timing is achieved by also the front airbag release control unit, the reclining position signal is supplied and the front airbag ignition timing in the lying position against a predetermined ignition at normal upright Backrest position is set later.

In known manner, the passenger seat should have a seat occupancy sensor and be used as a trigger condition for the rebound airbag and also for the front airbag a detected seat occupancy with.

It is also proposed to attach a pressure sensor in the upper seat mirror region of the backrest, with which it can be determined whether a seat occupant touches the backrest. As the triggering condition for the rebound airbag, the absence of such a pressure signal is taken into account in the control. This is another safety precaution, as the rebound airbag must under no circumstances be triggered if the seat occupant still touches the backrest.

When the seat back of the passenger seat is in the upright seating position, a seat occupant uses the harness system from the B pillar in a known manner as a restraint. When swung back in lying position backrest this belt system can not be used by the lack of coordination of the articulation points. It is therefore proposed for the passenger seat in a reclined position - with a rear seat behind it is not usable anyway - to use a fund seat belt assigned this rear seat by a load-bearing belt guide forward for a three-point belt system. With a modified embodiment of such a fund seat belt, in particular by a greater length, starting from a rear seat retractor, the belt is guided from an upper rear deflection point, optionally via a deflection point on the upper back outside, as a shoulder belt across a seat user to a tunnel-side seat belt buckle. From there, the belt runs as a lap belt to a swelling side outside, in particular on the seat part ride-mounted buckle and from there, if necessary, back to a lower Fondanlenkpunkt. Such a belt guide results in a well adapted to the love position retainer.

In a preferred embodiment, the rear seat retractor has a belt force limiter with a controlled variable belt force limiting level, wherein the Gurtkraftbegrenzungsniveau is set in relation to a normal rear seat belt use by a rear seat user to a lower level in the presence of a reclining position signal. When the rear seat belt is used by a rear seat occupant, the belt force limiter must be set to a relatively high level of force to preclude a rear impact of the rear occupant on the front seat back upright in a sitting position. When using the rear seat belt for the passenger seat in the lying position, however, it is advantageous to set a lower force level to allow the relatively large Vorverlagerungsweg for the upper body of a seat occupant from the lying position to the front airbag and to provide without the restraint system before the Pre-displacement finally slows down. The aim in the lying position is to bring about the best possible coordination between the belt force limitation of the rear retractor and the airbag system comprising the front airbag and rebound airbag.

The Reboundairbag may consist in a suitable embodiment of two gas cushion, one of which is in particular for shoulder support area inflatable in front of the backrest mirror and the second in particular for head support with greater depth in front of a headrest is inflatable.

In the event of optional equipment of a vehicle with a passenger seat with a reclining function, the rebound airbag deployment control unit may be useful as a separate unit in addition to a front airbag deployment control unit. Depending on the specific circumstances, however, the rebound airbag deployment control unit and the front airbag deployment control unit may also be integrated in one control unit.

In a drawing, an embodiment of the invention is explained in detail.

Show it:

1 a schematic side view of an occupant cabin of a passenger car in the area of a passenger seat with a seat occupant in a lying position;

2 a view accordingly 1 with a seat occupant after a frontal impact; and

3 a scheme for triggering a rebound airbag.

In 1 is a schematic side view of an occupant cabin 1 a passenger car with a view to a passenger seat 2 and a rear seat behind it 3 shown, with the vehicle doors are omitted.

The passenger seat 2 consists of a seat part 4 and one around an axis 5 swiveling backrest 6 ,

In the normal upright seating position of a seat occupant 7 is the backrest 6 largely upright and usually only by a relatively small angle α relative to a vertical 8th pivoted to the rear, as shown in dashed lines.

The passenger seat 2 Here is also designed so that the backrest 6 together with a headrest 9 by a relatively large angle β of about 40 ° to the vertical 8th to the rear in a reclining position as a rest position for the seat occupant 7 is pivotable, like this in 1 is shown. In this lying position is the seat user 7 with his shoulder area on the backrest 6 and with his head 10 on the headrest 9 on.

As a restraint device for the seat user 7 in its reclining position is not suitable for the seating position (not shown) belt system from the B-pillar but the belt system 11 for the underlying fund seat 3 used, whose Gurtverlauf is shown schematically:
The safety belt 12 is by a load-bearing belt guide forward to the passenger seat 2 led for a three-point belt. Starting from a (dashed line indicated) Fondgurtretraktor 13 the belt runs 12 over an upper Fondumlenkpunkt 14 to a turning point 15 on the upper back outside and from there across the seat user 7 as a shoulder strap 16 to a tunnel-side buckle 17 , From there, the belt continues as a lap belt 18 to a side of the sill on the outside of the seat part 4 moving seat belt buckle 19 and leads from there back to the rear area to a lower Fondanlenkpunkt 20 , The belt course is shown here in principle and can be adapted to the specific circumstances in a vehicle.

Based on 2 and 3 is a frontal crash situation with release of a front airbag and a rebound airbag shown:
In 2 is the position of the seat user 7 Immediately after a frontal crash shown, due to the sudden deceleration of the passenger compartment 1 the upper body 22 of the seat user 7 from the lying position is rotated far forward. This will be his upper body 22 and especially his head 10 through one already from a switchboard 23 unfolded front airbag 24 delayed as a passenger airbag delayed.

As a trigger condition for the front airbag 24 is a seat occupancy signal of a (schematically indicated) seat occupancy sensor 25 in the seat part 4 and the presence of a crash signal of a (not shown) crash sensor required.

Next are for the triggering of the front airbag 24 in a reclining position of the seat occupant 7 compared with the usual seating position following further modifications considered. Via a leaning angle sensor 26 the front airbag deployment control device (not shown) is supplied with the information that the backrest 6 in lying position, whereupon the ignition timing for the front airbag 24 is reset with respect to a normal release in the sitting position with an ignition delay, where with the larger rotational path of the upper body 22 from the lying position to the front airbag 24 Account is taken. Further, in the presence of the detected lying position a Gurtkraftbegrenzungsniveau a switchable (not shown) Gurtkraftbegrenzers the Fondgurtretraktors 13 reduced to a smaller value compared to a value for a normal use of the fund. This will be from the 2 apparent relatively long belt pullout for a torso rotation to the front airbags 24 allows.

In 2 is shown the state in which the upper body 22 of the seat user 7 already at the beginning of the reverse rotation phase (arrow 27 ) is located. At this time was already a rebound airbag 28 with a time offset to the ignition timing of the front airbag 24 triggered and unfolded in the manner shown. As conditions for the ignition of the rebound airbag 28 were in a (not shown) rebound airbag deployment control unit the presence of a crash signal and / or the ignition of the front airbag 24 as well as the detected lying position of the backrest 6 considered. Next is in the upper seat mirror area, a pressure sensor 29 attached, with which it is noticeable that the upper body 22 of the seat user 7 safe from the backrest 6 is lifted, which also as a trigger condition for the rebound airbag 28 is taken into account, otherwise the Reboundairbag 28 under no circumstances may be triggered.

The rebound airbag 28 consists of a lower gas cushion 30 and an upper gas cushion 31 which essentially the shoulder support and the head support in the back rotation (arrow 27 ) of the seat user 7 serve. The design of the rebound airbag 28 is shown here only in principle and can be adapted to the respective concrete circumstances exactly.

LIST OF REFERENCE NUMBERS

1

passenger compartment

2

passenger seat

3

rear seat

4

seat part

5

axis

6

backrest

7

seat occupant

8th

vertical

9

headrest

10

head

11

Fond belt system

12

Rear seat belt

13

Fondgurtretraktor

14

upper rear deflection point

15

turning point

16

shoulder

17

tunnel-side buckle

18

lap

19

Sill-side buckle

20

lower rear linkage point

21

Seat occupancy sensor

22

upper body

23

Switchboard

24

front airbags

26

Lean angle sensor

27

arrow

28

rebound airbag

29

pressure sensor

30

lower gas cushion

31

upper gas cushion

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69517432 T2 [0005]
• JP 1314645 A1 [0005]

Claims (10)

Safety device in a motor vehicle, with a vehicle seat ( 2 ), with at least one of a backrest ( 6 ) and / or a headrest ( 9 ) of the vehicle seat ( 2 ) in the direction of travel inflatable airbag in the manner of a rebound airbag ( 28 ), and with a Reboundairbag-release control device, which is connected to at least one crash sensor for detecting an accident, characterized in that the vehicle seat a passenger seat ( 2 ), whose backrest ( 6 ) to the rear in a lying position as a rest position for a seat user ( 7 ) is pivotable, that such a lying position by a reclining position sensor ( 26 ) and a reclining position signal in the rebound airbag deployment control device as a triggering condition for the rebound airbag ( 28 ) is taken into account. Safety device according to claim 1, characterized in that the lying position sensor as a rotation angle sensor ( 26 ) and / or is designed as a limit switch and that a reclining position signal is given at a leaning angle to the vertical of greater than 35 °, preferably at 40 °. Safety device according to claim 1 or 2, characterized in that the safety device further comprises a switchboard ( 23 ) out inflatable airbag as front airbag ( 24 ), with an associated, connected to the crash sensor front airbag release control unit, with which in a detected crash or pre-crash situation of the front airbag ( 24 ) is ignited at a predetermined front airbag ignition timing, and in contrast that the rebound airbag deployment control unit controls the rebound airbag (FIG. 28 ) ignites with an ignition timing offset of about 80 to 150 ms, preferably of 105 ms later, corresponding approximately to a front upper body position of a seat occupant ( 7 ) in the rotation phase. Safety device according to claim 3, characterized in that the front airbag deployment control unit with the reclining position sensor ( 26 ) is connected and set in the presence of a reclining position signal, the front airbag ignition timing with respect to a predetermined ignition timing at normal upright back position later. Safety device according to one of claims 1 to 4, characterized in that as a trigger condition for the rebound airbag ( 28 ) and optionally for a front airbag ( 24 ) the presence of a passenger seat signal from a seat occupancy sensor ( 21 ) is pulled out. Safety device according to one of claims 1 to 5, characterized in that as a trigger condition for the rebound airbag ( 28 ) the absence of a pressure signal of a pressure sensor ( 29 ) in the upper seat mirror region of the backrest ( 6 ) is pulled out. Safety device according to one of claims 1 to 6, characterized in that the safety device further comprises a restraint device for the passenger seat in lying position, in which a rear seat ( 3 ) behind the passenger seat ( 2 ) assigned rear seat belt ( 12 ) is guided by a load-bearing belt guide forward to a 3-point belt, in such a way that starting from a rear seat belt retractor ( 13 ) the strap from an upper rear deflection point ( 14 ), optionally via a deflection point ( 15 ) on the upper back outside, as a shoulder strap ( 16 ) across a seat user ( 7 ) to a tunnel-side buckle ( 17 ) and also from there as a lap belt ( 18 ) to a side of the sill, in particular on the seat part ( 4 ) mounted driving buckle ( 19 ) and from there to a lower rear linkage point ( 20 ) is guided. Safety device according to claim 7, characterized in that the Fondgurtretraktor ( 13 ) is equipped with a Gurtkraftbegrenzer with a controlled variable Gurtkraftbegrenzungsniveau, wherein in the presence of a Liegepositionssignals the Gurtkraftbegrenzungsniveau compared to a normal rear seat belt use by a rear seat occupant is set to a lower level /. Safety device according to one of claims 1 to 8, characterized in that the rebound airbag ( 28 ) from two gas bags ( 30 . 31 ) consists of which one, in particular for shoulder support surface in front of the backrest mirror is inflatable and the second in particular for head support with greater depth in front of a headrest ( 9 ) is inflatable. Safety device according to one of claims 1 to 9, characterized in that the rebound airbag deployment control unit and a front airbag deployment control unit are integrated in a deployment control unit.

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