Airbag device with arrester strap mechanism

Abstract

The present invention relates to an airbag device comprising at least one airbag module (1) and at least one arrester strap mechanism (2), wherein the at least one airbag module (1) comprises at least one airbag, and the at least one arrester strap mechanism (2) comprises at least one arrester strap arrangement and at least one tightening device (4) for the at least one arrester strap arrangement, wherein ends of the arrester strap arrangement are attached to the airbag, and the tightening device (4) pulls at least one arrester strap (3) of the arrester strap arrangement in a pulling direction (5) during a tightening operation, and wherein at least one backstop (6.1, 6.2, 6.3) is provided, by which the arrester strap (3) can be prevented from being pulled in a direction opposite to the pulling direction (5) after the tightening operation.

Description

[Technical Field]

[0001] The present invention relates to an airbag device having at least one airbag module and at least one arrester strap mechanism. The airbag module includes at least one airbag, and the at least one arrester strap mechanism includes at least one arrester strap arrangement and at least one tightening device for the at least one arrester strap arrangement. One end of the arrester strap arrangement is attached to the airbag, and the tightening device pulls the at least one arrester strap of the arrester strap arrangement in a pulling direction during a tightening operation.

[0002] The invention relates in particular to a vehicle seat for a motor vehicle having a backrest, a seat and such an airbag device, preferably with at least one fastening device arranged on the seat and at least one airbag module arranged on the backrest. [Background technology]

[0003] The airbag device may comprise two airbag modules, each arranged in a lateral region of the seat back, while two associated clamping devices are arranged in the seat, preferably with each airbag module assigned a clamping device.

[0004] The arrester strap arrangement may include just one arrester strap with one end attached to the airbag and the other end connected to a tightening device, or alternatively, the arrester strap arrangement may include multiple arrester straps connected to one another, with one of the arrester straps being directly connected to the tightening device to perform the tightening operation.

[0005] The clamping device preferably comprises a linearly accelerated element, the linear movement of which triggers the clamping action. The linear acceleration element can be driven in the drive direction, for example, by a pyrotechnic drive or a spring. The arrester strap connected to the clamping device can in this case be attached directly to the linearly accelerated element. However, it is also possible for the arrester strap to be fixedly connected to the clamping device and be deflected by the linearly accelerated element. In particular in the latter case, the distance traveled by the end of the arrester strap attached to the airbag can be greater than the distance traveled by the linearly accelerated element, so that a kind of pulley is formed in the clamping device.

[0006] The tightening device may, for example, comprise a tensioner tube in which a piston is disposed. When the piston is driven by compressed gas generated by a gas generator, the tensioner tube forms a kind of cylinder. The piston disposed in the tensioner tube / cylinder may be connected to the aforementioned linear acceleration element via a piston rod (which may also be called a rod-shaped adjustment element), so that the element is directly driven by the acceleration of the piston.

[0007] The aforementioned deflection element can be arranged at the end of the rod-shaped adjusting element opposite the piston. In this case, the clamping device is coupled to the arrester strap arrangement, particularly via the deflection element, and the arrester strap arrangement is deflected by the deflection element at least before and / or during the clamping operation. Thus, the portions of the arrester strap located in front of and behind the deflection element in the direction of the arrester strap are arranged at an angle relative to each other. For example, the arrester strap can be deflected by the deflection element by more than 60°, preferably more than 90°, or approximately 180°. The degree of deflection can be constant during the clamping operation, but can also vary during the clamping operation. In a preferred embodiment, the deflection element achieves a 180° deflection that does not change during the clamping operation. In particular, in this regard, the arrester strap can be fixed to one side of the rod-shaped adjusting element and guided in a guide on the opposite side for the clamping movement of the arrester strap, preferably extending laterally offset relative to the linear movement direction of the rod-shaped adjusting element. In particular, the arrester strap extends parallel to the direction of linear movement of the rod-shaped adjusting element before the tightening operation and preferably also during the tightening operation.

[0008] The arrester strap and the linear acceleration deflection element are arranged relative to one another in such a way that a kind of pulley is formed, with the deflection element forming a moving deflector. Thus, the end of the arrester strap arrangement attached to the airbag covers a longer distance during the tightening operation than the linear acceleration deflection element. In this regard, the arrester strap arrangement can have one or more deflection devices outside the tightening device, by which the arrester strap of the arrester strap arrangement is deflected.

[0009] The arrester strap or straps of the arrester strap arrangement are made in particular from a stretchable fabric and can be designed in the form of a strap or rope.

[0010] The deflecting element can preferably be arranged or formed directly on the rod-shaped adjusting element. However, in an alternative embodiment, a type of cage is arranged on the rod-shaped adjusting element, into which the deflecting element, for example as a deflecting roller, is mounted. The cage driven by the rod-shaped adjusting element is located in particular in the housing of the clamping device and, if necessary, can be guided by the housing during its linear movement.

[0011] In an initial state, airbags, particularly those located in the seatback of a vehicle seat, are designed to deploy next to and / or in front of an occupant seated in the vehicle seat after being triggered. The arrester strap arrangement may be configured to at least temporarily guide the deployment process during airbag deployment, for example, when the arrester strap arrangement is in a tensioned state. It is also conceivable that the arrester strap arrangement may unwind from a spool during deployment or be tightened from a wound or folded state by the deploying airbag.

[0012] A tightening device may be provided to retract the arrestor strap arrangement during deployment or at the end of the deployment process, thus influencing the deployment process, or to bring the airbag to a final position after deployment. For example, after deployment, a portion of the airbag mounted in front of the occupant may be pulled toward the seat back by the tightening device, such that the occupant is also pulled toward the seat back.

[0013] For example, U.S. Patent Application Publication No. 2019 / 0248322(A1) discloses a vehicle seat having the above-described airbag device, in which the tightening device rolls up the arrestor strap arrangement for the tightening action by a rotational movement. However, after the tightening action by rolling up the arrestor strap arrangement, the arrestor strap arrangement can be unrolled again, so that the occupant who was initially restrained by the airbag in the direction of the seat back can move away from the seat back again. However, it is desirable that the arrestor strap arrangement can no longer be pulled out after the tightening action. Summary of the Invention

[0014] The object of the present invention is therefore to overcome the drawbacks described with reference to the prior art, and in particular to identify an airbag device in which the retention function of an airbag connected to an arrester strap arrangement remains present even after the tightening operation has ended.

[0015] One possible solution to this problem is given by an airbag device having the features of the independent claims. Further solutions and advantageous developments of airbag devices are set out above and in the following specification, the individual features of the solutions and developments being capable of being combined with one another in a technically sensible manner.

[0016] This object is achieved in particular by an airbag device having the characteristics mentioned at the beginning, in which at least one backstop is provided, which can prevent the arrester strap from being pulled out in the direction opposite to the pulling direction after the tightening operation.

[0017] In other words, the basic idea of ​​the present invention is to provide a device element in which the backstop is configured to prevent an arrester strap, once pulled in the pulling direction by the tightening device, from being pulled again in the opposite direction, for example, by an occupant pressed into the airbag. For this purpose, one or more backstops can be provided. Multiple backstops with the same or different action mechanisms can be provided. Therefore, preferably, at least two backstops with different action mechanisms, or even three backstops with different action mechanisms, are provided. Thus, for example, at least one first backstop can act on a biasing element, which can be fixed against rearward movement in its position, particularly linearly displaced by the actuating device. At least one second backstop can act directly on an element of the actuating device (e.g., a spring or a rod-shaped element of a piston / cylinder arrangement). At least one third backstop can act directly on the arrester strap of an arrester strap arrangement. At least one backstop prevents the arrester strap from being pulled out at the end of the tightening operation, so that, if necessary, the backstop can be overcome to pull the arrester strap out in the opposite direction to the original pulling direction under very large forces.

[0018] In principle, the backstop can be arranged as a separate component from the clamping device. However, it is preferred that the backstop is integrated into the clamping device and / or attached as a component in / on the clamping device, so that the clamping device with the backstop can be attached to the vehicle seat as a structural unit. Therefore, in this case, the clamping device comprises at least one backstop, preferably all backstops.

[0019] In a first particular embodiment, it is proposed that the clamping device comprises a deflecting element, which can be driven in the drive direction as mentioned at the beginning, the deflecting element deflecting the arrester straps of the arrester strap arrangement within the clamping device, and at least one (first) backstop preventing movement of the deflecting element in a direction opposite to the drive direction.

[0020] In this connection, it may be possible in particular for the deflection element to be rotatably mounted on the cage, for example, and for the cage to be drivable in the housing in the drive direction, and for the (first) backstop to have a clamping element provided on the cage, which clamping element prevents movement of the cage in the housing in the direction opposite to the drive direction.

[0021] For example, components can be provided that prevent a biasing element that is linearly moved, for example, by a pyrotechnic drive or spring, from blocking or jamming when moved in a direction opposite to the drive direction. For example, plates, balls, rings, etc. may be arranged relative to one another such that corresponding movement in a direction opposite to the drive direction is prevented.

[0022] In this particular case, for example, a metal plate may be arranged on the cage so that it slides along the inside of the housing when the cage moves in the drive direction, and that when the cage moves in the opposite direction to the drive direction, the plate engages with its edge on the surface of the housing, thereby preventing backward movement of the cage.

[0023] Alternatively, one or several elements of the backstop can act on an element of the actuation device, in particular on a drivable rod-shaped adjusting element of the clamping device, with the backstop acting directly on the rod-shaped adjusting element. Thus, the piston rod of the piston / cylinder unit can be blocked in its extended position by a backstop that prevents the piston rod from moving backwards. Such a (second) backstop can act inside or outside the cylinder. At least two second backstops can also be provided, one of which acts on the piston rod inside the cylinder and the other outside the cylinder.

[0024] For example, the (second) backstop can have a first locking element that at least partially conically changes along the piston rod and a second locking element that interacts with the conical section of the first locking element. The locking element is preferably annular and surrounds the rod-shaped adjusting element. The two locking elements are arranged relative to each other so that the piston rod can be pushed out of the cylinder in the drive direction. Upon return movement of the piston rod, the first locking element interacts with the second locking element, thereby also stopping the return movement of the piston rod. During the return movement, the annular second locking element is clamped between the locking element and the piston rod by the conically tapering section of the first locking element, or between the conically tapering element and the inside of the cylinder. In contrast, when the piston rod moves in the drive direction, the annular second locking element rests on a flat surface aligned perpendicular to the piston rod so that the piston rod can move.

[0025] At least one (third) backstop can act directly on the arrester straps of the arrester strap arrangement, and in particular the (third) backstop can have a rib along which the arrester strap is guided, the rib being designed so that the arrester strap can move in the pulling direction and is blocked by the rib in the direction opposite to the pulling direction. The rib is in particular formed by a plurality of parallel elongated protrusions. In this case, the rib can be aligned in the pulling direction of the arrester strap so that the arrester strap is automatically pressed against the surface when moving in the direction opposite to the pulling direction.

[0026] In particular, the (third) backstop may have two groups of ribs between which the arrester strap is guided. The ribs may be formed as a single part on the component. For example, the longitudinally extending ribs may be aligned at an angle of, for example, 30° to 60° with respect to the tension direction of the arrester strap, so that the ribs press the arrester strap against the base of the backstop during movement in the direction opposite to the tension direction, especially if the two groups of ribs are aligned parallel to each other and have a certain distance from each other. However, the two groups of ribs do not need to be aligned strictly parallel to each other. Therefore, in a special embodiment, the ribs may be arranged in a V-shape relative to each other so that the distance between the two groups of ribs decreases in the direction of the ground along which the arrester strap moves during movement in the direction opposite to the tension direction, thereby increasing the clamping effect.

[0027] In addition, the mutual distance between the ribs arranged one behind the other in the direction of the arrester strap can be reduced in the tensile direction, thereby distributing the load more evenly within the arrester strap. Thus, two pairs of ribs arranged on either side of the arrester strap have a shorter distance from each other in the tensile direction than the pair of ribs arranged behind them.

[0028] In this regard, the (third) backstop may further comprise at least one cable guide designed and arranged so that the arrester straps are loaded against the bases of the ribs arranged in a V-shape relative to one another while the arrester strap arrangement is loaded in a direction opposite to the direction of tension. The cable guide may, for example, be formed by a protrusion arranged in front of or behind the rib in the direction of the arrester strap or another physical structure through which the arrester strap is guided, and the cable guide, when loading the arrester strap in a direction opposite to the direction of tension, loads the arrester strap at least partially in the direction of the bases of the V-shape rib, automatically clamping the arrester strap during its subsequent movement in the direction opposite to the direction of tension. [Brief explanation of the drawings]

[0029] The invention and the technical environment will now be described by way of example with reference to the figures, which show, in a simplified manner: [Figure 1] FIG. 1 is a portion of a frame of a vehicle seat having an airbag device. [Figure 2] FIG. 2 is a perspective view of a clamping device for an airbag device. [Figure 3] FIG. 3 is another perspective, partially cross-sectional view of the fastening device according to FIG. [Figure 4] FIG. 4 is a cross-sectional view of the clamping device according to FIGS. [Figure 5] FIG. 5 shows a cage with a deflection element of a fastening device. [Figure 6] FIG. 6 shows different possibilities for fastening the arrester strap to the housing of the tightening device. [Figure 7] FIG. 7 shows different possibilities for fastening the arrester strap to the housing of the tightening device. [Figure 8]FIG. 8 shows different possibilities for fastening the arrester strap to the housing of the tightening device. [Figure 9] FIG. 9 shows different possibilities for fastening the arrester strap to the housing of the tightening device. [Figure 10] FIG. 10 is a cross-sectional view of a fastening device having a first backstop. [Figure 11] FIG. 11 is a cross-sectional view of a fastening device having a second backstop. [Figure 12] FIG. 12 is a perspective view of the third backstop. [Figure 13] FIG. 13 is a cross-sectional view of the third backstop. [Figure 14] FIG. 14 is a top view of the third backstop. DETAILED DESCRIPTION OF THE INVENTION

[0030] Part of the frame of a vehicle seat is shown in Figure 1. The vehicle seat comprises a seat 17 and a backrest 16. An airbag device is incorporated into the vehicle seat and comprises two airbag modules 1 and two arrester strap mechanisms 2.

[0031] The airbag modules 1 are arranged in the side regions of the seat back 16. The airbags are shown only folded in their covers in Figure 1 and, when triggered, deploy in front of and / or next to an occupant sitting on the vehicle seat. Each airbag module 1 also comprises a gas generator capable of deploying the airbag.

[0032] Each arrester strap mechanism 2 has a tightening device 4 and an arrester strap arrangement. An arrester strap 3 of the arrester strap arrangement is connected to the tightening device 4, and one end of the arrester strap 3 is connected to an airbag. When triggered, the deploying airbag can be guided by the tightened arrester strap arrangement, and the arrester strap arrangement can be retracted by the tightening device so that the deploying or deployed airbag can be brought to a desired position.

[0033] The clamping device 4 shown in Figures 2 to 4 comprises a housing 9 in which a cage 8 is arranged, which can be driven for linear movement by a piston-cylinder arrangement. As is clear from Figure 5, the cage 8 is longer than it is wide in the driving direction so that the cage 8 does not get stuck in the housing 9. In addition, the cage 8 has a protruding shape extending in the longitudinal direction, which allows the cage 8 to be guided in the housing 9 with as little friction as possible.

[0034] The deflection element 7 for deflecting the arrestor strap 3 is mounted on the cage 8 .

[0035] The arrester strap 3 is fixed on one side of the piston-cylinder unit to an arrester strap fastener 19 on the housing 9. From this arrester strap fastener 19, the arrester strap 3 runs approximately parallel to the drive direction of the cage 8, is deflected by 180° by the deflection element 7 and exits the clamping device 4 through a third backstop 6.3.

[0036] 6-9 show various possibilities for how the arrestor strap 3 can be fastened to the arrestor strap fastener 19 on the housing 9. According to the embodiment of FIG. 6, a knot is introduced into the arrestor strap 3 so that the arrestor strap 3 cannot pass through the opening in the housing 9. According to the embodiment of FIG. 7, an eyelet is formed on the arrestor strap 3 outside the housing 9 of the tightening device 4, for example by stitching, so that the eyelet cannot be pulled through the opening in the housing 9, and thereby the arrestor strap 3 is fixed to the housing 9 upon triggering the tightening device 4. According to the embodiment of FIG. 8, a sleeve is fastened to the arrestor strap 3 by form-fitting and / or force-fitting or integrally, and the sleeve has a circumference larger than the opening in the housing 9. The sleeve can be fastened to the arrestor strap 3 in any suitable manner. According to the three embodiments of FIG. 9, a type of sleeve is applied to the end of the arrestor strap 3. The sleeve has a shape at its end that allows it to be fastened to the housing 9 of the tightening device 4. For example, the sleeve shown in Figure 9 above can be attached to the housing 9 by screws. The sleeve shown in the center and bottom of Figure 9 allows the sleeve to be secured to the housing with a form fit and / or a force fit.

[0037] When the clamping device 4 is actuated, a piston rod, also referred to as a piston-shaped adjusting element 12, is driven in a driving direction 11 within a cylinder 18 by compressed gas generated by a pyrotechnic drive or a spring. As a result, the arrester strap 3 is pulled into the clamping device 4 in a pulling direction 5. One end of the arrester strap 3 is fixed to an arrester strap fastener 19 on the housing 9, and the arrester strap 3 is deflected by 180° by a deflection element 7 so that the clamping path at the other end of the arrester strap arrangement is twice as large as the path covered by the adjusting element 12.

[0038] At the end of the tightening operation, it is desirable that the arrester strap 3 cannot be pulled out again from the tightening device 4. For this purpose, multiple backstops are proposed.

[0039] Figure 10 shows a first backstop 6.1 attached to the cage 8. Thus, a plate-shaped clamping element 10 is attached to the cage 8 and is bent so as to slide along the inside of the housing 9 during the clamping movement in the direction of the drive direction 11. However, when the cage 8 moves in the opposite direction to the drive direction 11, an edge of the clamping element 10 engages the inside of the housing 9, thereby preventing further movement in the direction opposite to the drive direction 11.

[0040] According to the second backstop 6.2 shown in FIG. 11, the first and second locking elements 13.1 and 13.2 are arranged inside the cylinder 18. Additionally, the first and second locking elements 13.1 and 13.2 are arranged outside the cylinder 18. The first and second locking elements 13.1 and 13.2 surround the rod-shaped adjusting element 12. The first locking element 13.1 has a conically tapered section that tapers in the opposite direction to the drive direction 11. The second locking element 13.2 is annular in design. During the tightening movement in the drive direction 11, the second annular locking element 13.2 lies on a flat surface oriented perpendicular to the drive direction 11 and does not interfere with the tightening movement. However, if the rod-shaped adjusting element 12 moves in the direction opposite to the drive direction 11, the second locking element 13.2 is pressed by the conical section of the first locking element 13.1 either against the inside of the cylinder 18 or against the adjusting element 12, thereby preventing movement of the adjusting element 12 in the direction opposite to the drive direction 11. The first locking element 13.1, which is arranged inside the cylinder 18, is therefore immovably connected to the adjusting element 12 and follows the movements of the adjusting element 12. However, the first locking element 13.1, which is arranged outside the cylinder 18, is fixed in place so that the adjusting element 12 can move relative to the first locking element 13.1.

[0041] 12-14 show the third backstop 6.3, which can also be seen in FIGS. 2 and 3. The third backstop 6.3 has two groups of ribs 14 between which the arrester strap 3 is guided. The arrester strap 3 enters the third backstop 6.3 between the ribs 14 via a cable guide 15. The ribs 14 are inclined relative to the longitudinal direction of the arrester strap 3, so that the arrester strap 3 is pulled onto the base 20 of the third backstop 6.3 under load in the direction opposite to the pulling direction 5. In addition, the two groups of ribs 14 are arranged relative to each other such that their distance toward the base 20 decreases. In a longitudinal view along the arrester strap 3, the two groups of ribs are arranged in a V-shape, which further increases the clamping effect while loading the arrester strap 3 in the direction opposite to the pulling direction 5. In addition, the mutual distance between the ribs 14 arranged one after the other in the direction of the arrester strap decreases in the pulling direction 5, thereby distributing the load more evenly within the arrester strap 3. Therefore, the two ribs 14 of a pair arranged on either side of the arrester strap 3 are at a shorter distance from each other than the pair of ribs 14 arranged behind them in the pulling direction 5 . [Explanation of symbols]

[0042] 1 Airbag Module 2 Arrester strap mechanism 3 Arrester Strap 4. Tightening Device 5 Pulling direction 6.1 First Backstop 6.2 Second Backstop 6.3 The third backstop 7 Deflection element 8 cages 9. Housing 10 Clamping Elements 11 Driving direction 12 Adjustment factors 13.1 First Locking Element 13.2 Secondary Locking Elements 14 Ribs 15 Cable guide 16 Backrest 17 sheets 18 cylinders 19 Arrester strap fastener 20 base

Claims

1. An airbag device comprising at least one airbag module (1) and at least one arrester strap mechanism (2), said at least one airbag module (1) comprises at least one airbag; the at least one arrester strap mechanism (2) comprises at least one arrester strap arrangement and at least one tightening device (4) for the at least one arrester strap arrangement; an end of an arrester strap arrangement is attached to the airbag, and the tightening device (4) pulls at least one arrester strap (3) of the arrester strap arrangement in a pulling direction (5) during the tightening operation; 1. An airbag device, characterized in that at least one backstop (6.1, 6.2, 6.3) is provided, by means of which the arrester strap (3) can be prevented from being pulled out in a direction opposite to the pulling direction (5) after the tightening process.

2. 2. An airbag device according to claim 1, wherein said tightening device (4) comprises said at least one backstop (6.1, 6.2, 6.3).

3. 3. The airbag device according to claim 1 or 2, wherein the clamping device (4) comprises a deflecting element (7) that can be driven in a drive direction (11), the deflecting element (7) deflecting the arrester straps (3) of the arrester strap arrangement within the clamping device (4), and at least one backstop (6.1, 6.2) preventing movement of the deflecting element (7) in a direction opposite to the drive direction.

4. 4. The airbag device according to claim 3, wherein the deflection element (7) is mounted on a cage (8), the cage (8) being capable of being driven in the housing (9) in the drive direction (11), and the backstop (6.1) has a clamping element (10) provided on the cage (8), the clamping element preventing movement of the cage (8) in the housing (9) in a direction opposite to the drive direction (11).

5. 4. The airbag device according to any one of claims 1 to 3, wherein the tightening device (4) comprises a drivable rod-shaped adjusting element (12), and the backstop (6.2) acts directly on the rod-shaped adjusting element (12).

6. 6. The airbag device according to claim 5, wherein the backstop (6.2) has a first locking element (13.1) that at least partially changes conically along the rod-shaped adjusting element (12) and a second locking element (13.2) that interacts with the conical portion of the first locking element (13.1).

7. 3. An airbag device according to claim 1 or 2, wherein a backstop (6.3) acts directly on the arrestor strap (3) of the arrestor strap arrangement.

8. 8. The airbag device according to claim 7, wherein the backstop (6.3) has ribs (14) along which the arrestor strap (3) is guided, the ribs (14) being designed such that the arrestor strap (3) is movable in the pulling direction (5) and is locked by the ribs (14) in the direction opposite to the pulling direction (5).

9. 9. An airbag device according to claim 8, wherein the backstop (6.3) has two groups of ribs (14) between which the arrester strap (2) is guided, the two groups of ribs (14) being preferably arranged in a V-shape relative to each other.

10. 10. The airbag device of claim 9, wherein the backstop (3) comprises at least one cable guide (15) designed and arranged such that the arrestor straps (3) are loaded against the bases of the ribs (14) that are arranged in a V-shape relative to one another when the arrestor strap arrangement is loaded in a direction opposite to the pulling direction (4).

11. A vehicle seat for a motor vehicle, comprising: - backrest (16) and - a seat (17), A vehicle seat comprising an airbag device according to any one of claims 1 to 10.

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