Safety device for a vehicle seat

Abstract

The invention relates to a safety device (5) with an airbag device (6) that can be integrated into a side structure of a vehicle seat (1) and a belt device (7) that can be integrated into the vehicle seat (1), wherein the airbag device (6) has an inflatable airbag (10), and the belt device (7) has a belt (15), a belt tensioner (16) and a tensioning element (9) connecting the belt (15) to the belt tensioner (16), wherein the belt tensioner (16) has a drive wheel (8) that can be driven to a rotary movement when the belt tensioner (16) is activated, and to which the tensioning element (9) is connected, wherein the drive wheel (8) has a first force transmission contour with a plurality of recesses and / or protrusions arranged in the circumferential direction, and the tensioning element (9) has a second force transmission contour (18) that corresponds in shape to the shape of the first force transmission contour.and the drive wheel (8) and the traction element (9) engage with each other by means of a positive-locking force-transmitting connection of the first and second force transmission contour (18), wherein the drive wheel (8) transmits the rotary movement upon activation of the belt tensioner (16) into a linear tensioning movement of the traction element (9).

Description

[0001] The present invention relates to a safety device for a vehicle seat having the features of the preamble of claim 1 and to a vehicle seat having the features of the preamble of claim 7.

[0002] Safety devices of the generic type comprise at least one airbag device integrated into a side structure of a vehicle seat and a belt device with a belt that is tightened upon activation of the safety device and, in the tightened position, holds an airbag inflated by the airbag device in position. Furthermore, a gas generator is provided, which, upon activation, suddenly generates a gas flow to inflate the airbag, which simultaneously serves to drive a belt tensioner associated with the belt of the belt device.

[0003] Such a safety device is known, for example, from the publication DE 10 2022 110 976 B3 and is also referred to as a seat cushion restraint system (SCRS). The belt device provided therein comprises a belt tensioner with a drive wheel designed as a gas turbine with turbine blades and a winding shaft which is connected in a rotationally fixed manner to the drive wheel of the gas turbine and to which a traction device connected to the belt is attached. When the safety device is activated, the gas generator suddenly releases a very large volume flow of gas, which inflates the airbag and is simultaneously directed to the drive wheel of the gas turbine in the belt tensioner, causing the drive wheel to rotate.Because the winding shaft is connected to the drive wheel in a rotationally fixed manner, when the safety device and the gas generator are activated, the winding shaft is suddenly driven in the winding direction of the traction device, so that the belt of the belt system connected to the traction device is tightened accordingly. The traction device is connected to the winding shaft in a tension-resistant manner and is thus wound onto the winding shaft when the safety device is activated. This known solution therefore requires at least a certain amount of installation space within the vehicle seat, which is defined by the winding shaft and the outer diameter of the traction device coil to be wound onto it.

[0004] The object of the invention is to provide a safety device of the generic type with a belt tensioner with improved force transmission to the traction means and a reduced installation space requirement.

[0005] To achieve this object, a safety device having the features of claim 1 and a vehicle seat having the features of claim 7 are proposed. Further preferred embodiments of the invention can be found in the subclaims, the figures, and the associated description.

[0006] According to the basic idea of ​​the invention, it is proposed that the drive wheel has a first force transmission contour with a plurality of depressions and / or elevations distributed in the circumferential direction and the traction means has a second force transmission contour corresponding to the shape of the first force transmission contour, and the drive wheel and the traction means engage with each other by a positive force-transmitting connection of the first and second force transmission contour, wherein the drive wheel transmits the rotary movement upon activation of the belt tensioner into a linear tensioning movement of the traction means.

[0007] With the proposed solution, power is transmitted through a positive-locking connection between the traction device and the drive wheel in a local, fixed power transmission zone in the area of ​​the traction device's run-up zone on the drive wheel, so that power transmission otherwise does not require a fixed connection between the traction device and the drive wheel. The traction device therefore no longer needs to be fastened and wound up on the drive wheel in a tensile manner, and can instead be guided further as desired starting from the power transmission zone. It is possible to wind up the traction device or even lead it away from the drive wheel, since the part of the traction device that has passed the drive wheel makes no further contribution to transmitting the tensioning movement. The belt tensioner can therefore be designed to be considerably more compact, at least in the area of ​​the drive wheel, since the traction device only needs to contact the drive wheel in the power transmission zone.

[0008] It is further proposed that the traction mechanism be inherently flexible. The flexible design of the traction mechanism allows it to adapt better to the external shape of the drive wheel in the area of ​​the power transmission zone, thus improving the power-transmitting engagement of the traction mechanism with the drive wheel. Furthermore, the section of the traction mechanism that has just passed the drive wheel exerts no or a significantly lower counterforce counteracting the tensioning movement when it encounters obstacles, as it can deform itself upon encountering such obstacles. Furthermore, after passing the drive wheel, the traction mechanism can be guided along any desired curve, thus allowing it to adapt better to available installation spaces.Since the traction element is exposed exclusively to tensile forces during power transmission, apart from minor lateral transverse forces due to the engagement of the gear teeth, the proposed flexibility is not a disadvantage. Flexible traction elements could include, for example, a flexible plastic, elastomer, or metal strip with a second power transmission contour, e.g., in the form of a toothed pattern or a regular structure of depressions or recesses, link chains with a chain structure corresponding to the shape of the first power transmission contour of the drive wheel, or similar.

[0009] It is further proposed that a collecting volume be provided on the belt pretensioner upstream of the tensioning movement of the traction mechanism to accommodate the traction element. This collecting volume can be formed by a suitable container or by a deliberately provided free space in the vehicle seat or on the belt pretensioner into which the traction element is discharged. For this purpose, the collecting volume is designed in terms of its size and arrangement to enable the controlled discharge and collection of the traction element.

[0010] It is further proposed that a gas generator be provided which, upon activation, suddenly releases a gas stream to inflate the airbag and drive the belt pretensioner. The airbag and belt pretensioner are thus activated simultaneously and, in a compact design, are exposed to a gas stream from a single gas generator. By appropriately designing the flow paths, a deliberate time offset in the activation or activation process of the airbag and belt pretensioner can be achieved.

[0011] It is further proposed that the belt tensioner comprise a mass body drive with a mass body chain, which, upon activation of the belt tensioner, can be driven to a drive movement during which it positively engages the outer contour of a second drive wheel connected to the drive wheel in a rotationally fixed manner. The proposed drive has the advantage of enabling a particularly long tensioning movement defined by the length of the mass body chain. The mass body chain can be stored in a tube with any desired configuration, the shape of which can be specifically adapted to the available installation space.

[0012] It is further proposed that the belt tensioner incorporate a backstop that counteracts the rotational movement of the drive wheel during the tensioning movement. This prevents the traction mechanism and thus the belt from reversing after the tensioning movement has been completed. The belt is essentially held in the tensioned position, thus supporting the airbag in its predetermined position.

[0013] To achieve this objective, a vehicle seat with two safety devices according to one of claims 1 to 6 is further proposed, comprising two identical airbag devices and two identical belt devices. The airbag devices and the belt devices are arranged symmetrically to a central axis on two opposite side structures of the vehicle seat. The proposed solution restrains the occupant sitting on the vehicle seat on both sides, thus providing lateral protection against an impact in both directions.

[0014] The invention will be explained below using preferred embodiments with reference to the attached figures. Fig. 1 a vehicle seat with a safety device according to a first and a second embodiment before and after activation; and Fig. 2 the vehicle seat of the Fig. 1 in an enlarged view; and Fig. 3 is an enlarged view of a drive wheel of the safety device with a belt tensioner according to the first and second embodiments; and Fig. 4 shows a vehicle seat with a safety device according to a third embodiment before and after activation; and Fig. 5 the vehicle seat of the Fig. 4 in an enlarged view; and Fig. 6 is an enlarged view of a drive wheel of the safety device with a belt tensioner according to the third embodiment; and Fig. 7 a drive wheel with a belt tensioner with a mass body chain; and Fig. 8 a seat cushion of a vehicle seat according to the invention with two safety devices before activation; and Fig. 9 a seat cushion of a vehicle seat according to the invention with two safety devices after activation.

[0015] In the Fig. 1, the left illustration shows a vehicle seat 1 with a seat cushion 3, a backrest 2 pivotally connected to the seat cushion 3 via a joint 14 and a headrest 4 arranged on the upper side of the backrest 2, wherein the same vehicle seat 1 in the upper illustration of the Fig. 2 in an enlarged section of the seat cushion 3 and the backrest 2. In the vehicle seat 1, a safety device 5 according to the invention with an airbag device 7 arranged in a lateral section of the backrest 2 and a belt device 7 can be seen before activation.

[0016] The belt device 7 comprises a belt 15, which is fastened at a first end in an upper section of the backrest 2, wherein it can be fastened to the backrest 2 separately via corresponding fastening means or via the airbag device 6. The belt 15 is laid such that it extends further through the backrest 2 downwards to the joint 14 and from there further through a lateral section of the seat cushion 3 to a deflection device 11 arranged on the front of the seat cushion 3. The belt 15 is deflected at the deflection device 11 and connected at its second end to a tension means 9 in a tensile-resistant manner.The traction means 9 has a second power transmission contour in the form of a toothing 17, with which it engages in a shape-corresponding second power transmission contour 18 of a drive wheel 8 and above it is in a positive connection of a power transmission zone with the drive wheel 8 in the area of ​​the run-up zone of the traction means 9 on the drive wheel 8.

[0017] The drive wheel 8 is in a rotationally fixed connection with a second drive wheel 13 of a Fig. 3, which drives the drive wheel 8 to a rotary movement when activated. The rotary movement of the drive wheel 8 is transmitted by the positive engagement of the toothing 17 of the traction means 9 into the first power transmission contour 18 of the drive wheel 8 into a linear pulling movement of the traction means 9. This pulling movement of the traction means 9 is then in turn transmitted to the second end of the belt 15 to tighten the belt 15, so that the belt 15, after activation of the belt tensioner 16 or the belt device 7, has the position shown in the middle illustration of the Fig. 1 and Fig. 2. The first power transmission contour 18 on the drive wheel 8 is designed to correspond in shape to the toothing 17 of the traction means 9, which in the simplest case can be realized by also designing this as a toothing. Alternatively, it is also sufficient if the drive wheel 8 has a first power transmission contour in the form of regularly arranged depressions, in which the traction means 9 engages with the tips of the toothing 17. Furthermore, the traction means 9 can also have a second power transmission contour in the form of regularly arranged recesses, e.g. in a ladder structure, wherein the first power transmission contour 18 on the drive wheel 8 can then also be designed as a type of toothing, which engages with the tips in the recesses of the ladder structure for power transmission in the power transmission zone. The first and the second power transmission contour are designed to correspond in shape, e.g.one of the force transmission contours is designed as a positive shape, and the other force transmission contour is designed as a negative shape. In this case, it is not necessary for the force transmission contours to bear against one another over their entire surface; it is sufficient if they bear against one another in a form-fitting manner in the circumferential direction and thus transmit the tensioning force. The first force transmission contour is arranged on the drive wheel 8 over its entire circumference on the radially outer surface of the drive wheel 8, and the second force transmission contour is arranged over the entire length of the section of the traction means 9 with which the traction means 9 passes the drive wheel 8 during the tensioning movement, so that the force-transmitting connection is not interrupted during the tensioning movement of the belt 15.

[0018] The airbag device 6 comprises an inflatable airbag 10, which, when the airbag device 6 is activated, is inflated to the extent shown in the middle illustrations of the Fig. 1 and Fig. 2 inflated geometry. The airbag device 6 is arranged in a laterally arranged section of the backrest 2, and the airbag 10 is inflated from the airbag device 6 upon activation from the backrest 2 in the direction of the seat cushion 3.

[0019] The belt 15 and the airbag 10 are geometrically coordinated in the tensioned or deployed position after tensioning and deployment such that the belt 15 supports the airbag 10 laterally and thus holds it in position. This support and holding of the airbag 10 in position can be further enhanced by connecting the belt 15 to the airbag 10, for example, by stitching or guide openings.

[0020] In the first embodiment, the traction means 9 is designed as a dimensionally stable rod and is thereby displaced backwards out of the seat cushion 3 past the drive wheel 8 when activated.

[0021] In the second one in the right representation of the Fig. 1 and the lower illustration of the Fig. In the embodiment shown in Figure 2, the traction means 9 is designed to be flexible, so that after passing the drive wheel, it can be received in a collecting volume 19 of the belt tensioner 16 or the seat cushion 3 provided for this purpose by multiple deformations in any direction, without emerging from the seat cushion 3.

[0022] Since, when the belt tensioner 16 is activated, the traction device 9 is only subjected to tensile stress in the section between the drive wheel 8 and the second end of the belt 15, its flexibility is not a disadvantage for force transmission. This flexibility is actually an advantage, as it allows the traction device 9 to adapt more effectively to the first force transmission contour 18 of the drive wheel 8. Furthermore, the traction device 9 can thus be folded more easily into the collecting volume 19. Due to the positive engagement in the first force transmission contour 18 and the ideally local, punctual force transmission effected in this area, the traction device 9 is only subjected to tensile stress in the section between the drive wheel 8 and the second end of the belt 15, while the section of the traction device 9 that has already passed the force transmission point of the drive wheel 8 is no longer subjected to any stress.

[0023] In the Fig. 3 shows the belt tensioner 16 according to a first embodiment. The belt tensioner 16 has a second drive wheel 13, which here is designed as a turbine wheel with radial vanes. Furthermore, a gas generator 12 is provided, which, when activated, suddenly releases a gas stream that drives the turbine wheel or the second drive wheel 13 to rotate. The second drive wheel 13 is connected in a rotationally fixed manner to the drive wheel 8, so that the drive wheel 8 is also driven to rotate as described above. At the same time, the gas stream generated by the gas generator 12 can also be used to inflate the airbag 10; for this purpose, the flow connections can be established by suitable gas lances or gas lines.

[0024] In the Fig. 4 and Fig. 5 shows the vehicle seat 1 with a safety device 5 according to a third embodiment. The safety device 5 of the third embodiment differs from the first two embodiments in that the traction means 9 is wound onto the drive wheel 8. For this purpose, the traction means 9 is fastened to the drive wheel 8 by its end via a fastening means 24, as shown in FIG. Fig. 6. The power transmission takes place in an identical manner via a second power transmission contour formed by a toothing 17 on the traction means 9 and a first power transmission contour 18 on the drive wheel 8. The traction means 9 is wound in several windings wound next to one another on the drive wheel 8 and therefore no longer needs to be subsequently removed.

[0025] In the Fig. Figure 7 shows an alternative embodiment of a belt tensioner 16 with a drive in the form of a mass body chain 20 consisting of a plurality of individual balls guided in a tube 25. The second drive wheel 13 here has an outer contour 27 with a plurality of regularly arranged dome-shaped depressions, which are adapted in shape to the outer shape of the individual balls and, through the engagement of the individual balls, enable a positive transmission of force from the individual balls of the mass body chain 20 to the second drive wheel 13. Furthermore, a collecting container 26 is provided, in which the individual balls are received after passing the second drive wheel 13. Furthermore, a backstop 21 is provided, which is connected to the drive wheel 8 and, via this, also to the second drive wheel 13, so that the drive wheel 8 and the second drive wheel 13 are blocked against reverse rotation after the tensioning movement has taken place.The drive wheel 8, the second drive wheel 13 and the backstop 21 are shown one above the other for the sake of easier recognition, but in practice they are of course arranged and connected coaxially and in a rotary joint and must be mentally imagined one after the other in the illustration.

[0026] In the Fig. 8 and Fig.Figure 9 shows a vehicle seat 1 according to the invention, viewed from above onto the seat cushion 3, before and after activation of two safety devices 5 provided therein. The safety devices 5 are arranged symmetrically to a central axis running in the longitudinal direction of the seat cushion 3. The drive wheels 8 of the safety devices 5 are arranged in pairs next to one another in a front section approximately in the middle of the seat cushion 3 and can thus be driven by a single belt tensioner 16 or by two separate belt tensioners 16. The belt tensioner 16 and the backstop 21 are shown separate from the drive wheels 8 to simplify identification; however, in practice, they are structurally connected to the drive wheel 8, whereby appropriate gears or fixed connections can be provided for the connection.The airbag devices 6 are not shown and must be imagined in a backrest 2 extending toward the viewer of the illustrations. The safety devices 5 each have a belt device 7 with a belt 15, which is each connected to the drive wheels 8 via a traction means 9. The belts are each arranged on opposite side structures 22 and 23 of the seat cushion 3, so that when activated, they support an inflated airbag 10 on the outside of both sides of the seat cushion 3. The occupant is thus restrained on both sides by inflated and supported airbags 10. List of reference symbols 1 vehicle seat 2 backrest 3 seat cushions 4 headrest 5 Safety device 6 Airbag device 7 Belt device 8 drive wheel 9 traction devices 10 airbags 11 Deflection device 12 gas generator 13 Second drive wheel 14 joint 15 belt 16 belt tensioners 17 Gearing 18 Second power transmission contour 19 Collection volume 20 Mass body chain 21 Backflow preventer 22 Page structure 23 Page structure 24 Fastening element 25 pipe 26 collection containers 27 Outer contour

Claims

[1] Safety device (5) with -an airbag device (6) which can be integrated into a side structure of a vehicle seat (1) and a belt device (7) which can be integrated into the vehicle seat (1), wherein -the airbag device (6) comprises an inflatable airbag (10), and -the belt device (7) comprises a belt (15), a belt tensioner (16) and a traction means (9) connecting the belt (15) to the belt tensioner (16), wherein -the belt tensioner (16) has a drive wheel (8) which can be driven to rotate when the belt tensioner (16) is activated and to which the traction means (9) is connected, characterized by , that -the drive wheel (8) has a first power transmission contour with a plurality of recesses and / or elevations distributed in the circumferential direction, and the traction means (9) has a second power transmission contour (18) corresponding to the shape of the first power transmission contour, and -the drive wheel (8) and the traction means (9) engage with each other by a positive force-transmitting connection of the first and second force transmission contours (18), wherein -the drive wheel (8) transfers the rotary movement upon activation of the belt tensioner (16) into a linear tensioning movement of the traction means (9). [2] Safety device (5) according to claim 1, characterized by , that -the traction means (9) is flexible in itself. [3] Safety device (5) according to one of claims 1 or 2, characterized by , that -on the belt tensioner (16) in relation to the tensioning movement of the traction means (9) upstream there is provided a collecting volume (19) for receiving the traction means (9). [4] Safety device (5) according to one of claims 1 to 3, characterized by , that -a gas generator (12) is provided which, when activated, suddenly releases a gas stream to inflate the airbag (10) and to drive the belt tensioner (16). [5] Safety device (5) according to one of claims 1 to 4, characterized by , that -the belt tensioner (16) has a mass body drive with a mass body chain (20) which, upon activation of the belt tensioner (16), can be driven to a drive movement during which it comes into positive engagement with an outer contour (27) of a second drive wheel (13) which is connected in a rotationally fixed manner to the drive wheel (8). [6] Safety device (5) according to one of claims 1 to 5, characterized by , that -the belt tensioner (16) has a backstop (21) acting counter to the rotational movement of the drive wheel (8). [7] Vehicle seat (1), characterized by , that -two safety devices (5) according to one of claims 1 to 6 with two identical airbag devices (6) and two identical belt devices (7) are provided, wherein the airbag devices (6) and the belt devices (7) are arranged symmetrically to a central axis on two opposite side structures (22, 23) of the vehicle seat (1).

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