Description

Technical field of the invention

The invention relates to a vehicle seat for a motor vehicle with a side airbag according to the preamble of Claim 1 and a motor vehicle with such a vehicle seat according to Claim 12.

The use of side airbags is widespread in vehicle technology. Such side airbags serve to protect the occupant to whom they are allocated in the case of a side impact or in the case of an accident in which the vehicle overturns. For this, the side airbag is arranged in or on the side bolster of the backrest of the motor vehicle seat or in the lateral structure of the motor vehicle, and in the case of an accident expands between the occupant and the vehicle structure, generally resting against the vehicle structure. The side airbag has a ventilation opening, so that, on impact of the occupant, gas can escape from the interior of the airbag througth this ventilation opening and thereby impact energy is dissipated. Without the presence of such a ventilation opening, the occupant would rebound back into the interior of the vehicle from the impact surface of the side airbag, which of course is not desired.

The problem exists that with given airbag volume and with given gas generator output, the size of the ventilation opening would have to be tuned in relation to the weight of the occupant, in order to achieve an ideal protective effect for the respective occupant. In the case of a heavy occupant, the ventilation opening would have to be relatively small, so that the side airbag remains relatively hard and the occupant is prevented from striking through onto the vehicle structure. In the case of a light occupant, the ventilation opening would have to be relatively large, in order to make the side airbag softer.

Prior art

To solve the problem which has just been mentioned, EP 1 568 644 A1 proposes providing a first ventilation opening in a side wall of the side airbag, namely in the side wall pointing towards the inside, which also forms the impact surface. The position of this ventilation opening is selected so that it is covered by the shoulder region of a tall occupant, but is not covered by the shoulder region of a short occupant. If a tall, and hence generally heavier, occupant strikes onto the side air- bag, the shoulder region blocks or throttles the ventilation opening and the side airbag remains accordingly hard. If, on the other hand, a short, and hence gener- ally lighter, occupant strikes onto the impact surface of the side airbag, then this ventilation opening remains open and the side airbag shows a correspondingly soft behaviour. An adaption of the ventilation therefore takes place as a function of the size of the occupant.

A disadvantage here is firstly that the ventilation opening must be hit relatively precisely, in particular even when the occupant is not in his standard sitting position (out of position). A further disadvantage is that the adaptation of the ventilation takes place substantially "digitally", which means that the ventilation is either open or closed. Graduations lying therebetween are relatively difficult to realise.

Summary of the invention

Starting from this, the present invention sets itself the problem of improving the prior art to the effect that the ventilation adaptation is substantially independent of the sitting position of the occupant at the onset of the accident.

This problem is solved by a vehicle seat with the characteristics of Claim 1 and by a motor vehicle with the characteristics of Claim 12. According to the invention, the ventilation opening, through which the degree of hardness of the side airbag is set, is situated on the side wall of the side airbag pointing outwards, i.e. towards the side wall of the vehicle. It is not the shoulder region of the occupant, but rather the door of the vehicle, namely the region below the door railing, which therefore serves for the possible closing of this first ventilation opening. The control factor here as to whether the side airbag behaves in a hard or a soft manner in the case of a side impact is not directly the body size of the occupant, but rather the vertical adjustment of the vehicle seat, i.e. only indi- rectly the body size of the occupant. This means that the invention obligatorily presupposes a height adjustable vehicle seat.

If a height adjustability is present for the vehicle seat, then this is generally used at least on the driver's side, with a tall driver adjusting the seat low and a short driver adjusting the seat high. The position of the first ventilation opening can therefore be easily selected so that it comes to lie above the door railing of the door in the highest seat position and below the door railing of the door in the lowest seat position of the vehicle, when the side airbag is in its completely deployed state. This first ventilation opening is therefore closed by abutment against the door in the case of a tall occupant, i.e. with a low set seat , but not in the case of a short occupant, i.e. with a high set vehicle seat. This functions very reliably and independently of the actual sitting position of the occupant during the accident, and the sealing effect by the rigid structure of the door is very high. A further advantage is that a direct flowing of hot gases against the occupant is ruled out.

In preferred embodiments according to Claims 6 or 7, the ventilation opening consists of several single openings, whereby a very fine tuning of the airbag hardness can be achieved.

The invention will now be explained in further detail by ways of preferred embodiments with reference to the figures, in which are shown: Brief description of the drawings

Figure 1 a diagrammatic plan view onto a driver's seat, mounted in a motor vehicle, with a side airbag, wherein this side airbag is illustrated in completely deployed, but undisturbed state,

Figure 2 that shown in Figure 1 , with a tall occupant sitting on the vehicle seat,

Figure 3 that shown in Figure 2 after striking of the occupant onto the side airbag, Figure 4 that shown in Figure 3 with a short occupant sitting on the vehicle seat, wherein the vehicle seat is situated in an upper vertical adjustment,

Figure 5 that shown in Figure 4 after striking of the occupant onto the side airbag, Figure 6 a perspective illustration of a situation as corresponds approximately to the situation of Figure 5,

Figure 7 a lateral view onto a vehicle seat with a side airbag and

Figure 8 a ventilation opening which is covered by a covering cloth.

Detailed description of preferred embodiments

Figure 1 shows a vehicle seat 10, namely a driver's seat, in the mounted state in the motor vehicle. The vehicle floor 40, the vehicle roof 42 and the roof rail 44 can be seen diagrammatically. On the outside, adjacent to the vehicle seat, the vehi- cle door 45 is situated, which comprises a main body 46 extending up to the door railing 47, and a window frame 49, of which an upper section can be seen here. When the side window 50 is closed, it extends between the door railing 47 and the window frame 49. In addition, a storage compartment 48 can be seen, which is formed on the main body 46 of the vehicle door 45.

The vehicle seat 10 has a diagrammatically illustrated height adjustment 18, by means of which the vertical position of the vehicle seat 10 can be set with respect to the vehicle floor 40. Figure 1 shows the vehicle seat 10 in its lowest adjustment. Further, a side airbag 20 in its completely deployed state is illustrated in Figure 1. In this completely deployed state, the side airbag 20 extends from the outer side bolster 14a of the backrest 14 forwards and substantially parallel to the vehicle door 45. The side airbag 20 is filled by a gas generator which is, however, not illustrated here.

The side airbag 20 has a first side wall 22 pointing towards the occupant and a second side wall 24 pointing towards the outside. The first side wall 22 therefore serves as an impact surface and the second side wall 24 serves as a support surface.

Two ventilation openings are provided, namely the first ventilation opening 30 and the second ventilation opening 38. The first ventilation opening 30 serves to con- trol the internal pressure, i.e. the hardness, of the side airbag 20 on impact of an occupant onto the impact surface of the first side wall 22. For this, the first ventilation opening 30 is located on the outwardly-pointing second side wall 24 in the region of the height of the door railing 47. As can be seen from Figure 1 , the first ventilation opening 30 is arranged in the second side wall 24 of the side airbag 20 so that with a completely deployed airbag 20 and with a height adjustment of the vehicle seat in its lowest position, it is situated below the door railing 47 of the vehicle door 55. The second ventilation opening 38 is situated in a front region, approximately in the transition region between the first side wall 22 and the second side wall 24 and is arranged so that it remains open in every case.

Figure 2 shows the items shown in Figure 1 , with a tall occupant G sitting on the vehicle seat 10.

Figure 3 shows the items shown in Figure 2, after the tall occupant, as the result of an accident, has struck onto the first side wall 22 of the side airbag 20 and the latter is supported by the vehicle door 45, namely its main body 46, by means of its second side wall 24. Owing to the position of the first ventilation opening 30 described above, the latter strikes onto the outer surface of the main body 46 of the vehicle door 45 below the door railing 47 and is thereby fully blocked or at least throttled. Because the main body 46 of the vehicle door 45 is a very rigid body, an almost complete blocking of the first ventilation opening 30 is practically always given, independent of the exact sitting position of the occupant. In this case, the ventilation of the side airbag 20 takes place exclusively via the second ventilation opening 38, whereby the side airbag 20 remains relatively hard.

Figure 4 shows what is shown in Figure 2, when a short occupant K is sitting on the vehicle seat 10. The vehicle seat 10 is set into an upper position correspond- ing to the size of the occupant K, as can also be seen from the illustration of the diagrammatically illustrated height adjustment 18. Through this raised position of the vehicle seat 10, compared with the state shown in Figure 2, the first ventilation opening 30 is situated above the door railing 47. If, as illustrated in Figure 5, the short occupant K strikes onto the first side wall 22 of the side airbag 20 and the latter rests by means of its second side wall 24 against the main body 46 of the vehicle door 45, then the first ventilation opening 30 does not come in contact with the main body 46 of the vehicle door 45 and therefore remains open, because the side window is offset outwards with respect to the inwardly pointing surface of the main body 46 and in addition is generally destroyed in the case of a side impact, so that it does not offer any abutment surface in this case. The first ventilation opening 30 therefore does not come into abutment or only with very little force - if the side window 50 is reached - against a surface. Hereby, gas flows off both through the second ventilation opening 38 and also through the first ventilation opening 30, and the side airbag 20 becomes soft accordingly.

From the preceding illustration of the invention, it can be seen that the second ventilation opening, which always has the same effective cross-section, serves for the rough tuning of the side airbag and therefore is primarily adjusted to the volume of the side airbag and the gas generator output, but not to the respective ve- hide occupant. The first ventilation opening serves for the fine tuning of the side airbag as a function of the size of the occupant who is to be protected. The rough tuning and the fine tuning are fully decoupled from each other. It can further be seen from the preceding illustration of the invention that it only functions optimally when the occupant who is to be protected carries out the applicable seat height adjustment for his body size. This is in fact generally the case, but particularly on the passenger side it can happen that the occupant does not carry out the applicable seat height adjustment, in particular that a short occupant sits too low, and in the case of an accident the first ventilation opening is therefore positioned below the door railing. Owing to the low weight of the short occupant, the first ventilation opening is, however, pressed with a smaller force against the door than by a tall occupant, so that it is generally not fully closed, which attenu- ates the effect of the "incorrect use". As the side walls of the side airbag have a convex shape, the force transmission between the door and the second side wall 24 of the side airbag is largest in the middle of the second side wall 24. It can therefore be advantageous to arrange the first ventilation opening 30 eccentrically, i.e. in a margin region of the second side wall 24, in order to intensify the effect described above, namely that the first ventilation opening is not fully closed when it is pressed by a short (and light) occupant against the door.

Figure 6 shows a situation which corresponds substantially to the one of Figure 5, in a perspective illustration. It can be seen from this figure that the first ventilation opening 3 can also consist of several single openings 31 , here namely two. The same also applies to the second ventilation opening 38. It is further indicated in Figure 6 that the first ventilation opening 30, here therefore the two single openings 31 , can be covered with a covering cloth 36, which improves the sealing effect in the case of an abutment against the vehicle door 45. Such a covering cloth is also illustrated again in Figure 8, from which it can also be seen that this covering cloth, which covers the first ventilation opening 30, is sewn by means of preferably only one fastening seam 37 to the second side wall 24. The advantage of such a covering cloth 36 is in particular that the first ventilation opening is also reliably closed when it strikes onto the vehicle door precisely in the region of the door railing, i.e. "on the edge". In this case, without such a covering cloth, a "half open" state occurs which is difficult to define. Figure 7 shows a vehicle seat 10 with a side airbag 20 in a side view. It can be seen from this figure that the first ventilation opening 30 can also be embodied as a field 32 of single openings with several rows, in the example embodiment shown with three rows 34a, 34b, 34c. The height of this field 32 of single openings corre- sponds preferably substantially to the height adjustability of the vehicle seat. The dot-and-dash lines in Figure 7 show here the relative position of the door railing 47 in the uppermost and lowermost adjustment of the vehicle seat 10. Through such an arrangement, a very fine tuning of the airbag hardness is obtained as a function of the vertical position of the vehicle seat and therefore also as a function of the size of the vehicle occupant. The desired effect of a finer graduation, compared with a sole single opening forming the ventilation opening, can also already be achieved by two single openings which are arranged substantially on top of one another. However, a field of single openings improves both the fineness of the graduation and also the reproducibility.

List of reference numbers

10 vehicle seat

12 seat surface

14 backrest

14a,b side bolster

18 height adjustment

20 side airbag

22 first side wall

24 second side wall

30 first ventilation opening

31 single opening

32 field of single openings

34a first row

34b second row

34c third row

36 covering cloth

37 fastening seam

38 second ventilation opening

40 vehicle floor

42 vehicle roof

44 roof rail

45 vehicle door

46 main body

47 door railing

48 storage compartment

49 window frame

50 side window

G tall occupant

K short occupant