DE102012010771A1 - Method for folding rider air bag for occupant restraint system of motor car, involves lifting part of compressed air bag from working face by using eccentrically engaging traction units so as to form one pleat in compressed air bag - Google Patents

Abstract

The method involves centrally fixing a blank holder (12) with a working face (16) placed on a compressed rider air bag (10). A part of the air bag is lifted from the working face by using eccentrically engaging traction units so as to form one pleat in the air bag. The two eccentrically engaging traction units are connected together at different distances from a holding-down device. The second eccentrically engaging traction unit is used to engage at catch tape attachments of the gas bag. A folding container and the traction units are moved in same direction. Independent claims are also included for the following: (1) an air bag (2) an air bag module.

Description

The invention relates to a method for folding an airbag for an occupant restraint system of a motor vehicle. In addition, the invention relates to a folded gas bag and an airbag module with such a gas bag.

Vehicle occupant restraint systems typically include airbag modules that include an airbag that inflates in the event of an impact to reduce the likelihood of collision of body parts of a vehicle occupant with a vehicle component. Some of these gas bag modules are intended to be fixed as driver airbag modules in the steering wheel of a motor vehicle. Here, the airbag is arranged in a housing of the airbag module in a folded state, wherein it is particularly important that the folded airbag, d. H. the gas bag package, the smallest possible volume. It is also important that the gas bag can deploy in fractions of a second when triggered. The aim of the development of new folding techniques of gas bags is therefore to collapse the gas bag as small as possible in order to minimize the necessary storage space, while ensuring an unobstructed deployment of the airbag.

So far, it has been proposed to perform the folding of the gas bag by means of Zughüllen, which are placed around the gas bag and passed through an opening in a contact plate. The gas bag is thereby folded in the outer casing. The use of a Zughülle for folding a gas bag is, for example, in EP 1 293 396 B1 disclosed. In this case, however, it is necessary for the gas bag to be removed from the outer casing before being transferred to an airbag module receptacle. There are also proposals to pressurize the gas bag from the inside with compressed air, so that the gas bag bulges in spaces between several boundary plates. By subsequent pressing of the gas bag and at the same time removing the boundary plates results in a regular folding. Inside the gas bag, however, a substantially unused free volume remains. Such a production method is in EP 0 850 161 B1 described.

The object of the invention is to specify an alternative method which makes it possible to fold an airbag, in particular to produce the smallest possible volume of a folded airbag. Furthermore, it should be procedurally ensured that the gas bag can deploy freely in a crash and, preferably, can inflate. It is also an object of the invention to provide such a gas bag and an airbag module with such a gas bag.

According to the invention this object is achieved by a method by the subject of claim 1.

The invention is therefore based on the idea of specifying a method for folding an airbag for an occupant restraint system of a motor vehicle, in which the gas bag spread out on a work surface is fixed centrally with a hold-down device. At least one part of the gas bag is lifted off the work surface with an off-center pulling means such that at least one fold forms.

The advantage of the method according to the invention is that with simple means a reproducible folding of the gas bag can be achieved. Moreover, with the invention, a method is provided in which the gas bag can be folded to a particularly small volume, since no means, such as compressed air, must be introduced into the gas bag. Furthermore, the method according to the invention allows a direct transfer of the folded gas bag into an airbag module, since the folding without external, the gas bag enclosing elements is made possible. Also, the method allows to obtain a directed inflation of the airbag.

According to a preferred embodiment of the method according to the invention, at least two traction means are provided which are equidistant from the hold-down device (FIG. 12 ) with the gas bag ( 10 ) are connected.

According to another preferred embodiment of the method according to the invention at least two traction means are provided, which are connected at different distances to the hold-down with the gas bag.

By means of the at least two traction means it is achieved that the airbag can be folded defined at several locations. By the traction means engage at different distances to the center of the airbag or the hold-down on the airbag, different folding areas can be distinguished in the folded airbag package. Overall, it is thus achieved that the folded airbag package occupies the smallest possible volume.

Preferably, at least a first traction means engages a circumferential seam.

It is also preferred that at least one second pulling means acts on a tether attachment of the gas bag.

These sites are characterized by a particularly good strength and are therefore suitable good for fixing the traction means. The traction means may be clamped to the gas bag. In other words, the traction means may comprise brackets, which are connectable to the gas bag, preferably a peripheral seam and / or a tether attachment of the gas bag.

Furthermore, it can be provided that in a further method step, a folding container is pushed over the hold-down device, which pretends at least a portion of the outer shape of the folded gas bag. Once the traction means has lifted a portion of the airbag from the work surface and thus formed a fold in the airbag, the folding container can be pushed over the airbag, so that prevents the airbag automatically unfolds again. It is advantageously provided that the folding container dictates the outer radial shape of the folded gas bag, in particular the shape of the gas bag receptacle, for. B. in a steering wheel, reproduces. Thus, the folded airbag, d. H. the airbag package, are used directly from the folding container in an airbag receptacle or a module receptacle.

Preferably, the folding container and the traction means are moved in the same direction. In other words, it is provided in a preferred embodiment that the traction means, which lifts a part of the airbag from the working surface in a first direction and the folding container in the same, first direction is moved to, in particular from below, over the To push gas bag. This avoids that, as the folding container advances, one edge of the folding container catches on a fold and unfolds the gas bag or releases it from the traction means.

The traction means is preferably released from the gas bag in a further method step. In particular, the traction means is released from the (partly) folded airbag as soon as the airbag is completely arranged in the folding container. The folding container prevents the airbag from unfolding again. Thus, the traction means for this is no longer necessary and can be removed.

In a further preferred embodiment it is provided that the hold-down is removed after folding the airbag. The hold-down has the function of applying a counterforce to the tensile force of the traction device on the gas bag to ensure that only a part, preferably an edge region of the gas bag is pulled upwards. Once the traction means removed or at least the folding container is guided over the airbag, there is no longer any need to exert such a hold-down force on the airbag. By removing the hold-down, further volume remains available, which can be filled by the airbag material. Overall, the result is a relatively small total volume of the folded airbag or airbag package.

Furthermore, it is provided that the folded gas bag is pressed with a press ram. The ram can be moved in a direction which extends in opposite directions to the direction of movement of the traction means and / or the folding container. By pressing the airbag, the volume of the airbag package is further reduced. For this purpose, a press ram is used which is preferably moved in a second direction opposite to the first direction. This has the advantage that the press ram can be moved against a bottom plate of the folding container, that is, the airbag is compressed between the bottom plate of the folding container and the press ram.

In a particularly preferred embodiment, a total of four traction means are provided, of which two first traction means each at a 12 o'clock position and a 6 o'clock position and two second traction means each at a 3 o'clock position and a 9 o'clock position attack the gas bag. It has been found that with four regularly spaced traction means a particularly good folding can be achieved. The convolution can be called star-shaped. By the respective opposite traction means, which are arranged with the same distance to the hold-down on the airbag, a particularly uniform and volume-saving folding is achieved.

With regard to an airbag, the object is achieved by the features of claim 8.

Such an inventive gas bag is characterized by its low volume in the folded state. By defined defined fold or folds, the airbag has an advantageous deployment characteristic, which allows a faster deployment in the axial direction of the airbag, whereby the airbag provides a softer reception of him body part of the occupant contacting.

With regard to an airbag module, the object is achieved by the features of claim 9.

Preferred embodiments are the subject of the respective subclaims.

The invention will be explained in more detail below with reference to an embodiment with reference to the accompanying drawings. Therein show the 1 to 8th single steps of the Inventive method for folding a gas bag according to a preferred embodiment.

1 shows a first step of the method according to the invention, wherein the method is used for folding a driver's airbag. The driver airbag or gas bag 10 is on a work surface 16 been spread. The gas bag 10 has a substantially circular shape, but also different contours are conceivable. In the middle of the work surface 16 is an opening 21 arranged so that one under the work surface 16 arranged funnel 19 is accessible. In the funnel 19 is also a lifter plate 17 arranged. The detail view in 2 shows the ejector plate 17 , the funnel 19 and the opening 21 in the workspace 16 ,

In the spread state on the work surface 16 is the gas bag 10 So also on the lifter plate 17 on. The ejector plate 17 is stored so that it can be lowered down. The funnel 19 is with a folding container 13 connected or connectable.

In the further course of the process, the gas bag 10 on the desktop 16 spread out, with a hold-down 12 fixed. The hold down 12 presses on the middle of the gas bag 10 so that the gas bag 10 between the hold down 12 and the ejector plate 17 is clamped or fixed.

In a next step of the procedure, which in 3 is shown, traction means 14 used on the gas bag 10 attack. The traction means are preferably formed as cords, which at a central point above the working surface 16 are merged. At the ends of the traction means 14 Clamps are arranged with the gas bag 10 are connectable. In total there are four traction devices 14 provided, wherein in each case two opposite traction means 14 with the same distance to the middle or to the hold-down 12 on the gas bag 10 attack. In particular, it is provided that two first traction means 14a at the circumferential seam 20 of the gas bag 10 attack or are clamped there. Two second traction devices 14b on the other hand, they are attacking tether attachments 22 of the gas bag 10 on or are clamped there. The first traction means 14a are arranged opposite each other, so are at a 3 o'clock or 9 o'clock position with the gas bag 10 connected. By contrast, the second traction means 14b , which are also arranged opposite, at a 6 o'clock or 12 o'clock position on the gas bag 10 clamped.

The specified 3, 6, 9, 12 o'clock positions of the airbag are defined on the orientation of the normal in the steering wheel or vehicle installed and inflated airbag.

In a next step, the traction means 14 up, ie with respect to the hold-down 12 pulled substantially in the axial direction. This direction of movement corresponds to the first direction (axial direction or axial deployment direction of the airbag). As a result, wrinkles form at defined locations 18 , In 4 is, for example, well recognizable that 4 diagonal folds occur at the 1:30 h, 4:30 h, 5:30 h, 10:30 h positions of the gas bag, which accelerates deployment of the gas bag, in particular the central portion of his front (occupant facing) panels, effect in the axial direction.

In 4 is also well recognizable that the second traction means 14b longer than the first traction means 14a are formed. Thus it is achieved that further wrinkles 18 in particular due to the location of the tether fasteners 22 of the gas bag 10 clamped traction means 14b are trained or become.

Instead of attaching the traction means at the points of the tether attachments 22 is an attachment of the traction means at any predefined locations between the periphery and the center of the front panel of the airbag conceivable.

The other wrinkles 18 preferably extend wholly or partially through the point of approach of the traction means along an imaginary connecting line from the edge of the airbag to its center.

More wrinkles 18 preferably extend wholly or partially through the starting point of the traction means perpendicular to the line imagined by the starting point of the traction means from the edge of the airbag to its center.

The further folds may preferably also extend from the starting point of the traction means to the region of the edge of the airbag, from which also the diagonal traps 18 extend to the center of the gas bag.

Overall, this Faltart allows the production of a particularly compact airbag package.

In a next process step, the funnel 19 , which is below the work surface 16 in the area of the opening 21 is arranged, upwards, ie along the first direction, driven. The funnel is with a folding container 13 connected, which is thus on the folded gas bag 10 ' pushes. The folding container 13 has an inner contour corresponding to the inner contour of the airbag receptacle, in which the gas bag 10 should be used. Once the folded gas bag 10 ' completely in the folding container 13 is arranged ( 5 ), the traction means 14 from the gas bag 10 be solved and removed. Furthermore, after the arrangement of the folded gas bag 10 ' in the folding container 13 the hold down 12 to be reduced ( 6 ). The folded gas bag 10 ' is now on the lifter plate 17 on and is laterally through the folding container 13 kept in shape.

In the next process step comes a press stamp 15 used, its stamp plate 11 has an outer contour, the inner contour of the folding container 13 equivalent. The stamp plate 11 will be in the folding container 13 used and then pressed down, that is moved in the opposite direction of the first second direction, so that the folded airbag 10 ' between the ejector plate 17 and the press stamp 15 is compressed. The compressed gas bag 10 thus has a relatively low volume, so it requires relatively little space. A top view of the folded and pressed airbag shows 8th ,

In the illustrated embodiment of the method according to the invention is provided for simplicity that the press ram 15 through the hold-down 12 and the stamp plate 11 is formed. Thus comes the hold-down 12 a double function too. On the one hand, the hold-down effect 12 in a first phase of the method, the fixation of the gas bag 10 on the work surface 16 , On the other hand, the hold-down 12 used to the folded gas bag 10 ' to compress. Thus, the structure of a corresponding device for carrying out the method simplified.

In subsequent method steps, a cover cap or an airbag receptacle can now be placed on the folding container 13 be put on. The connection between the cap and the folding container 13 is preferably the same as the connection between the folding container 13 and the funnel 19 In the meantime, from the folding container 13 was removed. Once the cap on the folding container 13 is attached, the folding container 13 moved back, ie under the work surface 16 sunk, so that by the relative movement between the folding container 13 and the ejector plate 17 the folded gas bag 10 ' is pressed into the cap. In the cap now the folded airbag 10 be fixed.

LIST OF REFERENCE NUMBERS

10

airbag

10 '

Folded gas bag

11

stamp plate

12

Stripper plate

13

folding container

14

traction means

14a

First traction means

14b

Second traction means

15

press die

16

working surface

17

Ausheberplatte

18

wrinkle

19

funnel

20

circumferential seam

21

opening

22

Tether attachment

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

• EP 1293396 B1 [0003]
• EP 0850161 B1 [0003]

Claims (12)

Method for folding a gas bag ( 10 ) for an occupant restraint system of a motor vehicle, wherein the on a work surface ( 16 ) spreading gas bag ( 10 ) with a hold-down ( 12 ) fixed in the middle and at least a part of the gas bag ( 10 ) with an off-center pulling means ( 14 ) from the desktop ( 16 ) is raised so that at least one fold ( 18 ). A method according to claim 1, characterized in that at least two traction means ( 14 ) are provided, which preferably at the same distance to the hold-down ( 12 ) with the gas bag ( 10 ) are connected and / or preferably at different distances to the hold-down ( 12 ) with the gas bag ( 10 ) are connected. A method according to claim 1 or 2, characterized in that at least one traction means ( 14a ) at a circumferential seam ( 20 ) and / or at least one traction means ( 14b ) at any predefined location between a circumferential seam ( 20 ) and a center of a front panel of the airbag ( 10 ), preferably in the region of a tether attachment ( 22 ) of the gas bag ( 10 ) attacks. Method according to one of the preceding claims, characterized in that at least one traction means ( 14a ) at a 6 o'clock position and / or at least one traction means ( 14b ) at a 12 o'clock position of the gas bag ( 10 ), wherein preferably at least two traction means ( 14 ) are provided, each of which a traction means ( 14a ) at a 12 o'clock position and a 6 o'clock position, and / or one traction means each ( 14b ) on a 3 o'clock position and a 9 o'clock position on the gas bag ( 10 ), and further preferably at least four traction means ( 14 ) are provided, of which two first traction means ( 14a ) at a 12 o'clock position and a 6 o'clock position, and two second traction means ( 14b ) on a 3 o'clock position and a 9 o'clock position on the gas bag ( 10 attack). Method according to one of the preceding claims, characterized in that via the hold-down ( 12 ) a folding container ( 13 ), which in particular predetermines a section of an outer shape of the folded gas bag, wherein preferably the folding container ( 13 ) and the traction means ( 14 ) are moved in the same direction. Method according to one of the preceding claims, characterized in that the traction means ( 14 ) during or after folding of the gas bag ( 10 ) and / or that the hold-down ( 12 ) after folding the gas bag ( 10 ) Will get removed. Method according to one of the preceding claims, characterized in that the folded gas bag ( 10 ' ) with a punch ( 15 ), wherein the pressing punch ( 15 ) is moved in a direction which is opposite to the direction of movement of the traction means ( 14 ) and / or the folding container ( 13 ). Airbag folded in particular according to a method according to one of the preceding claims. Airbag according to claim 8, characterized in that folds ( 18 ) are formed at defined locations, preferably diagonal folds ( 18 ), which extends from a central region of the gas bag at 1:30 h, 4:30 h, 5:30 h and / or 10:30 h positions of the gas bag to its peripheral seam ( 20 ), and / or preferably wrinkles ( 18 ), the locations of the tether attachments ( 22 ) of the gas bag ( 10 ) are formed. Airbag according to claim 8 or 9, characterized in that folds ( 18 ) are formed at defined locations, preferably diagonal folds ( 18 ), which extends from a central region of the gas bag at 1:30 h, 4:30 h, 5:30 h and / or 10:30 h positions of the gas bag to its peripheral seam ( 20 ), and / or preferably wrinkles ( 18 ), the locations of the tether attachments ( 22 ) of the gas bag ( 10 ) are formed. Airbag according to one of claims 8 to 10, characterized in that folds ( 18 ) formed by a point of attachment of the temporarily attached traction means or the tethers ( 22 ) to the area of the peripheral seam ( 20 ) of the airbag, from which also diagonal folds ( 18 ) extend to the center of the gas bag. Airbag module, in particular driver airbag module or passenger airbag module with an airbag and a gas generator for inflating the airbag, characterized in that the airbag ( 10 ) is folded according to a method according to one of the preceding claims 1 to 7 and / or formed according to one of claims 8 to 11.

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