Side protection for motor vehicle occupants, with seat=mounted airbag

The invention relates to an occupant-side protection for a motor vehicle, with at least an integrated in a seat of the motor vehicle and, when activated by itself open seam of a reference of the seat exiting side airbag.

As one part of the security aspect in motor vehicles are becoming increasingly important wins, it but by design is not possible on the other hand, in the side walls or doors of motor vehicles to accommodate sufficiently strong crumple zones to at a lateral collision by another vehicle or an obstacle the majority convert the kinetic energy into deformation work, are increasingly Motor vehicles as standard or optionally equipped with side airbags that at a Deformation of the respective side wall or door is automatically activated and within less fraction is inflated so as a protective air cushion between the deformed side wall or door and one on the adjacent seat of the form motor vehicle seated occupant.

The placement of a folded side airbags for the driver or a Passenger can take place in the doors of the motor vehicle, such as in the GB-A-2255535 proposed. However, front side airbags have a relative in this case having large volume to in all adjustable positions of the seat front seats adequate protection for it seated differently sized To ensure vehicle occupant. Will you take the time to complete inflation of not extend side airbags at the expense of a greater security risk, so one needs correspondingly larger sized inflators.

This drawback is avoided if the folded airbag on the vehicle seat is mounted as disclosed in DE-OS 43 07 421st To accommodate the folded airbag is there a rigid plastic case, either side or below of the vehicle seat or laterally fixed to the backrest and has pre-weakened seams that in the activation of the side airbag in a predetermined manner tear to the airbag in the desired position between to the driver and passenger chest-hip area of ​​a part, and the door on the other hand to steer. However, the side on the seat protruding plastic case for Disabled two-door motor vehicles affects the entry of rear seated occupants and also aesthetically very appealing, firstly because it survives and others because it is made of plastic, so that it particularly in expensive interiors does not fit right to the seat covers.

In contrast, the overall aesthetic impression is not affected if the Side airbag is integrated in the interior of the vehicle seat and upon activation an opening seam in the seat fabric emerges as disclosed in EP-A 0,565,501. however Studies have shown that when use union seat covers not the seam itself, but weakened by the seam punctures fabric uncontrollably on a Side of the seam to tear when the side airbag is inflated after an activation, resulting in an undefined discharge of the air bag, so that this in inflated state not always occupies the intended position.

Proceeding from this, the invention has the object, an occupant-side protection to provide the above-mentioned type in which the airbag during inflation at a provided exit site beyond the suture of the opening seam, so that it then inflated always a predetermined location reproducible restraining action takes.

This object is inventively achieved by the characterizing feature of the Patent claim 1. After that, the invention is distinguished occupant Side protection is characterized in that the seam opening at least in the area of provided airbag exit point a lower capacity than neighboring seams of Seat cover has. The invention is obtained by the investigations Based on experience that the seams of seat covers in general rather be oversized, since this complaints about damaged seams safely be avoided without much higher by the stronger suture Costs caused. On the other hand, it is thus easily possible in the Range of the intended exit point airbag seam opening or a portion weaker perform this stitching, without thereby in their life conditions of use will be reduced.

While the term "the opening to seam" one of a seam beginning to is meant a seam end by sewn seam that the range of the intended Airbag exit location comprises and upon inflation of the air bag on a part of its length or ruptures in their entirety, to the term "adjacent seams of Seat cover "seams are understood to be at one of the ends of the opening Connecting seam, parallel to this, or have an education that corresponding to that of the opening seam, ie, for example like this as welted seam are formed.

A preferred embodiment of the invention provides that the load capacity of up openable seam in the region of the intended airbag exit point at 40 to 80% and preferably is 50 to 75% of the carrying capacity of the adjacent seams. This ranges in conventional stitched seat covers, on the one hand, ensure that during inflation the side airbag is not the fabric but the suture tears without On the other hand weakened seam over an acceptable for their durability beyond what becomes.

Due to technical reasons, a further preferred embodiment of the The invention provides that the portion of lower load on at least one side extends across the intended exit point airbag addition, preferably to a Point at which the seam opening collides with another seam or up to an edge of the cover, ie, usually to a position at which the suture opening is scheduled or completed.

While it would be possible, although the capacity of the opening by a seam larger stitch spacing to reduce. However, since this is visible on closer inspection, provides a further preferred embodiment of the invention that a top or Bobbin thread at least one row of stitching the opening seam is thinner than that of the Stitch number (n) of the neighboring seams, so that its tensile strength is lower. The lower tensile strength can be further with by using a suture achieve a different composition whose strength properties at the same Strength under which the suture of the neighboring seams lie.

Alternatively, the load can be in the area of ​​intended airbag exit point also be reduced in that the opening seam in this area, or any its entire length a smaller number of adjacently arranged rows of stitches than the adjacent seams.

To do without changes to the seat and reference design, is the envisaged Airbag outlet point is preferably arranged in the region of a seam, to the Sewing together two parts of the seat cover is used, preferably between a Front part and a pointing towards the door or side wall or lateral side and Back part of the backrest upholstery, as this spot is closest to having intended position of the inflated side airbags and this seam from folded airbag in the direction of travel from that lies in the direction in which the to deploy side airbags. Alternatively, the proposed airbag exit point could also Region of a seam between an upper part of the seat upholstery cover and one of the door or Sidewall adjacent side portion thereof to be arranged, in this case, the side airbag to unfold upwards.

Basically could for the airbag exit point but also an additional seam in Seat cover are provided, however, this due to the greater workload is not preferred.

In the following the invention with reference to an illustrated in the drawings Embodiment explained in more detail. Show it:

<b>Fig.</b> 1 is a perspective view of a vehicle seat with an integrated folded airbag;

<b>Fig.</b> 2 is a front side view of the backrest of the vehicle seat from <b>Fig.</b> 1;

<b>Fig.</b> 3 is a schematic perspective view of a welted seam in the area of provided airbag exit point.

The vehicle seat shown in the drawing <b>1</b> consists essentially of a seat cushion <b>2</b> and an adjustable backrest <b>3</b> with headrest <b>4</b>, With a reference <b>5</b>. <b>6</b> made of leather or fabric, optionally in combination with a Plastic covering material are provided, as well as one in the backrest <b>3</b> integrated side airbags <b>7</b> (Not shown) with associated inflator.

The seat upholstery <b>5</b> consists of a three-part shell <b>8th</b> and two side parts, which one (<b>9</b>) Forward to the seat cushion <b>2</b> extends around, while the other its in the drawing is not visible back closes. In contrast, the Backrest cover <b>6</b> in addition to a three-piece front <b>10</b> a continuous back and side part <b>11</b> to the with the edges of the front portion <b>10</b> is sewn. Next is both the top <b>8th</b> the seat cushion cover <b>5</b> as well as the front part <b>10</b> the backrest upholstery <b>6</b> with several longitudinal and transverse thereto stitching <b>12</b>. <b>13</b>. <b>14</b>. <b>15</b>. <b>16</b>. <b>17</b> provided, however, to be noted that this is neither provided must be such as a three-part design of the front part or a continuous Forming the back and side part.

The folded side airbag <b>7</b> is below a release lever <b>18</b> for the backrest <b>3</b> in a housing (not shown) within the padding of the backrest <b>3</b> mounted ,. that it is in when activated out of the housing Direction a to the front part <b>10</b> the backrest upholstery <b>6</b> circulating and this with the back and side <b>11</b> connecting seam <b>19</b> to open and this by Enlargement of its volume at a certain, indicated by small crosses Length bursts so that it through the open seam <b>19</b> emerge and inflated State an intended position between the vehicle seat <b>2</b> adjacent door or side wall (not shown) and on the vehicle seat <b>2</b> sitter can occupy.

In order to prevent that, in place of the seam <b>19</b> the textile fabric or the Plastic cover material of the backrest upholstery <b>6</b> Near the intended Airbag exit point <b>20</b> tear, with the result that the airbag <b>7</b> in other than the expand desired direction and therefore not inflated would occupy predetermined position, the seam opening <b>19</b> lower Endurance as adjacent seams of the seat cover <b>5</b>. <b>6</b> on, that is, their capacity is less than that of two connecting seams <b>21</b> the three-piece front part here <b>10</b>, a the backrest cover <b>6</b> closing at the lower end, if necessary by sewn Plastic hook strips realized seam (in the drawing is not visible), or a corresponding to the upper part <b>8th</b> the seat cushion cover <b>5</b> circumferential seam <b>22</b>,

This lower loading capacity can be achieved in that at least one of both strands of the region of the intended exit point Airbag <b>20</b> used Suture, preferably the lower thread is thinner and thus less Tensile strength than that of the aforementioned adjacent seams <b>21</b>. <b>22</b>, Possibly also the stitching <b>13</b>. <b>14</b>. <b>15</b>. <b>16</b>. <b>17</b>That for production reasons mostly are sewn with the same suture material as the other seams of the seat cover. As for the neighboring seams <b>21</b>. <b>22</b> generally an upper thread and a lower thread with equal strength, each preferably 40/3 (40 m / g, 3 monofilaments) and from the same material (preferably polyamide 6.6) is used, the seam <b>19</b> on your total length, including the expected airbag exit point <b>20</b>Ie around the front <b>10</b> the backrest upholstery <b>6</b> around stitched with a suture, in which Although the threads of the same material (also preferably polyamide 6.6) exist, however, in which the lower thread with a thickness of 80 m / g is only half as thick as the upper thread. The latter has with 40/3 the same strength as that of the adjacent seams <b>21</b>. <b>22</b> on, so that it during the fabrication of a seat cover <b>5</b>. <b>6</b> not to be changed needs.

When in <b>Fig.</b> 3 welted seam shown <b>19</b> is the piping <b>25</b> on the front part <b>10</b> (Or at Back and side <b>11</b>) With a suture <b>26</b> sewn, wherein the denier the upper and the lower thread with 40/3 equally strong. Subsequently, the two parts <b>10</b>. <b>11</b> as described above in the region of the intended exit point Airbag <b>20</b> or preferably beyond the start to the end of the seam <b>19</b> with a suture <b>27</b> sewn lower strength, the upper thread has a thickness of 40/3 and having the lower thread of 80/3. This ensures that the piping<b>25</b> not of the reference part <b>10</b> (or <b>11</b>) Dissolves, at which it was sewn in the first stage, so that it does not cross over the airbag exit point <b>20</b> and thus span the airbag and those in the worst case in the area of ​​the seam <b>19</b> can restrain.

The use of a thinner lower thread is sufficient to tear strength and thus the strength of the seam <b>19</b> to decrease, since these are essential thread gage is proportional. Furthermore, the use of a thinner lower thread (or possibly Alternatively, a thinner needle thread) at all with the automobile Sewing or stitching of upholstery <b>5</b>. <b>6</b> Seam types used, ie Just seam, flat seam, double lap and welted seam or lockstitch or Double chain stitch seam possible while at the seams with several parallel rows of stitches, as For example, a double lap all rows of stitches with a thinner or lower Upper thread are sewn. The stitch spacing of the seams<b>19</b> or. <b>21</b>. <b>22</b> is the same and is suitably between 3.5 and 4.5 mm, preferably 4 mm.

In seams with two or more parallel rows of stitches, the resilience of the seam <b>19</b> in the Region of the intended exit point Airbag <b>20</b> or moreover also characterized be reduced by the number of rows of stitches is less in this area.