Seat belt device with an inflatable cushion

Abstract

The invention relates to a seat belt device (1) with an inflatable cushion arranged on the diagonal belt section (15), a gas generator (7) for inflating the cushion, wherein a gas lance (18) with an outlet opening (41) and in fluidic communication with the gas generator (7) is provided on the belt buckle (5), and a connection piece (17) connected to the cushion in terms of flow is provided on the belt tongue (6), wherein the gas lance (6) is fixed in the guide tube (25) by a holding part and / or a frictional force up to a limit force to be overcome, wherein the holding part and / or the frictional force are dimensioned such that the limit force to be overcome force is exceeded when the gas generator (7) is activated by the gas flow and pressure generated thereby and the gas lance (18) is displaced to such an extent that it passes with the outlet opening (41) the seal (28) of the connection piece (17), and the seal (28) comes to rest in a sealing manner against an outer wall (42) of the gas lance (18).

Description

[0001] Autoliv Development AB, 44783 Vargarda, SE

[0002] Seat belt device with an inflatable cushion

[0003] The invention relates to a seat belt device with an inflatable cushion having the features of the preamble of claim 1.

[0004] Seat belt devices in motor vehicles have been state of the art for a long time and serve to restrain the occupant in the event of an accident in order to avoid serious injuries. In particular, three-point seat belt systems have proven effective, which have a seat belt that can be attached at one end to the vehicle structure or to the vehicle seat itself via an end fiting that can be fixed to the vehicle, on one side of a vehicle seat, and can be wound up via a belt retractor that can be fixed to the vehicle seat or the vehicle structure on the same side of the vehicle seat.

[0005] A belt tongue is also slidably guided on the seat belt strap, which tongue can be locked in a belt buckle fastened on the other side of the vehicle seat to realize the three-point geometry and, in the locked position, divides the seat belt into a diagonal belt section extending from the belt buckle diagonally across the chest of the occupant to the retractor and a lap belt section extending from the belt buckle to the end fiting over the pelvis of the occupant.

[0006] Furthermore, it is known to provide an inflatable cushion on the diagonal belt section, which is inflated in front of the chest of the occupant in the event of an accident.

[0007] A restraining system with a seat belt device of this kind is known from the publication DE 10 2021 111522 Al, in which a gas generator is provided on the belt buckle, which, when activated, suddenly releases a gas flow to inflate the cushion. An inflation hose is provided to create a fluidic connection between the gas generator arranged on the belt buckle and the cushion arranged on the diagonal belt section. The document does not disclose how the fluidic connection between the gas generator and the inflation hose is realized.One problem is that the gas generator assigned to the belt buckle is to be regarded as stationary due to its arrangement on the belt buckle, while the cushion assigned to the diagonal belt section is not stationary due to the mobility of the diagonal belt section. This means that the fluidic connection must be reestablished each time the seat belt is put on and must be realized practically via a detachable interface.

[0008] In view of this, the object of the invention is to provide a seat belt device with an inflatable cushion and a gas generator arranged on the belt buckle, which is designed in such a way that the fluidic connection between the cushion and the gas generator can be reliably established by anyone without any detailed technical skills or prior knowledge each time the seat belt is put on, wherein the seat belt buckle must not be impaired in its functionality by the application and in the applied state.

[0009] To solve the problem, a seat belt device with the features of claim 1 is proposed. Further preferred developments are shown in the sub-claims, the figures and the associated description.

[0010] In accordance with the basic idea of the invention, it is proposed that a guide tube be provided on the belt buckle, in which the gas lance is displaceably guided, and the connection piece comprises a tubular pressure compartment, which is fl uidica lly connected to the cushion and comprises a seal at the end facing the gas lance, wherein the gas lance is fixed in the guide tube by a holding part and / or by a frictional force up to a limit force to be overcome, the holding part and / or the frictional force being dimensioned such that the limit force to be overcome is exceeded when the gas generator is activated by the gas flow and pressure produced thereby and the gas lance is displaced to such an extent that it passes with the outlet opening the seal of the connection piece, and the seal comes to rest in a sealing manner against an outer wall of the gas lance comes to rest in a sealing manner on an outer wall of the gas lance.

[0011] Before the gas generator is activated, that is during normal use of the seat belt device, the gas lance is held in position by the holding part and / or the frictional force, so that it cannot perform any uncontrolled movements until the predetermined limit force is reached. Thelimit force is defined by the nature of the holding part itself and its connection to the gas lance and / or the guide tube and / or by the magnitude of the frictional force. The limit force is dimensioned in such a way that it is only exceeded when the gas generator is activated and the pressure exerted on the gas lance as a result. In an initial phase of the gas generator activation, the gas lance is pushed until the outlet opening passes a seal in the connection piece of the belt tongue and is thereby moved into a sealed pressure compartment of the connection piece. Subsequently, the cushion is inflated in a sealed form with lower losses via the connection piece by the gas lance.

[0012] Furthermore, it is proposed that a stop be provided on the gas lance and / or on the guide tube to limit the sliding movement of the gas lance. The stop defines a predetermined end position of the gas lance, which is preferably dimensioned so that the gas lance is not in contact with the inner wall of the connection pipe and the gas flow can flow as freely as possible from the gas lance into the connection pipe.

[0013] It is further proposed that the stop is formed by a damper. The proposed solution stops the movement of the gas lance in a damped manner, so that the acting forces are reduced by at least part of the kinetic energy being absorbed in the damper.

[0014] It is further proposed that the damper be of a ring-shaped design so that the deceleration of the gas lance occurs with forces that are as evenly distributed as possible and with the lowest possible local loading of the gas lance and the guide tube. In addition to the even distribution of forces, the tendency of the gas lance to tilt when it strikes the damper can also be reduced. The gas lance is thus held in position better.

[0015] Furthermore, it is proposed that the damper be designed to be elastic and that it comes into contact with the outer wall of the gas lance through elastic deformation when the gas lance is in the stop position. The proposed further development additionally braces and fixes the gas lance in the area of the damper. In addition, the damper can also act as a seal between the gas lance and the guide tube when the gas lance is in the stop position, which can further increase the efficiency of the rotation tightener. Furthermore, this can prevent or at least reduce the escape of the hot gas stream from the belt buckle.It is further proposed that the seal comprises a resilient sealing lip having a sealing surface that tapers in the direction of the sliding movement of the gas lance. The proposed solution simplifies the retracting movement of the gas lance into the connection nozzle because the seal thereby has an additional centering effect. In addition, the sealing effect is improved because the seal makes contact with the sealing lip over the entire circumference of the outer wall of the gas lance. In particular, slight deviations of the gas lance from a central position can be compensated.

[0016] It is further proposed that the gas lance comprises a conical end face at its end facing the connection nozzle, in which the discharge opening is arranged. The conical shape of the gas lance end face further simplifies the insertion movement of the gas lance into the connection nozzle. The end face is conical with an outer diameter that decreases towards the end.

[0017] It is also proposed that several outlet openings be provided, which are arranged so as to be evenly distributed around the circumference of the conical end face. The proposed further development can fulfill the criterion of thrust neutrality, so that the seat belt device does not execute any sudden recoil-related movements when the gas generator is unintentionally activated.

[0018] It is further proposed that a second tube is provided in the guide tube, which second tube comprises a smaller external diameter than the internal diameter of the guide tube to form an annular pressure compartment, and the gas lance comprises a pressure compartment into which the second tube projects, wherein the gas lance seals the annular pressure compartment and is guided in a sealing manner on the second tube. The gas lance is firstly guided through the second tube and secondly an annular pressure compartment is formed thereby and sealed to the gas lance, into which the gas flow flows in an initial phase of the extension movement of the gas lance and drives the gas lance to the extension movement.

[0019] It is further proposed that the second pipe is dimensioned in length such that the gas lance loses the sealing guide on the second pipe during the extension movement after it passes the seal of the connection nozzle with the outlet opening and the seal comes into sealing contactwith an outer wall of the gas lance. The gas flow thus flows into the annular pressure compartment between the guide tube and the second tube until the gas lance has passed the seal of the connection nozzle with the outlet opening.

[0020] The invention is explained in more detail below with reference to various embodiments. The figures show:

[0021] Fig. 1 a seat belt device according to the invention; and

[0022] Fig. 2 an enlarged section of a vehicle seat with an occupant and a belt buckle with a belt tongue of the seat belt device according to the invention locked therein; and

[0023] Fig. 3 the belt buckle with the belt tongue as individual parts; and

[0024] Fig. 4 an enlarged section of the belt tongue with the belt buckle in different views; and

[0025] Fig. 5 the belt tongue and the belt buckle as individual parts; and

[0026] Fig. 6A-E the gas lance in various positions during an extension movement when the gas generator is activated.

[0027] Figure 1 shows a seat belt device 1 according to the invention, with a seat belt 2, two belt retractors 3 and 4, a belt buckle 5, a gas generator 7, a belt tongue 6, a deflection device 11 and a belt guide part 12.

[0028] The deflection device 11 and the belt guide part 12 each comprise a belt slot or a belt guide opening through which the seat belt 2 is guided and / or deflected to form a predetermined path. For this purpose, the deflection device 11 and the belt guide part 12 are fixed to a vehicle seat, to a B-pillar, C-pillar or another point on the vehicle structure in a manner fixed to the vehicle.The seat belt 2 comprises two separate belt sections 37, 38 which can be wound up with their first ends on one of the retractors 3 or 4. The retractors 3 and 4 are in turn attached to the vehicle structure or to the vehicle seat itself on one side of a vehicle seat in a manner fixed to the vehicle and, in a blocked position of a belt reel on which the belt sections 37 and 38 can be wound up, form a connection, fixed to the vehicle, of the ends of the belt sections 37 and 38 to the vehicle structure.

[0029] The other ends of the belt sections 37 and 38 are attached to the belt tongue 6, which can be locked in the belt buckle 5, which is attached to the vehicle structure on the other side of the vehicle seat or to the vehicle seat itself, in order to realize the three-point geometry. The belt buckle 5 is connected to a holding element 8 that can be fixed to the vehicle by means of a flexible pull cable 9. Furthermore, a gas generator 7 is provided, which is fastened in a manner fixed to the vehicle via a holding part 39, which can be seen in Fig. 3, and is connected in a flow-through manner via a flexible filling hose 10 to a gas lance 18, which can be seen for example in Fig. 5, of the belt buckle 5.

[0030] In the locked position of the belt tongue 6, this results in a three-point geometry of the seat belt 2, in which one belt section 37 forms a lap belt section 14 crossing the pelvis of the occupant and the other belt section 38 forms a diagonal belt section 15 from the belt tongue 6 to the deflection device 11 and a vertical section 13 from the deflection device 11 over the belt guide 12 to the belt retractor 3. around device 11 and a vertical section 13 from the around device 11 over the belt guide part 12 to the belt retractor 3. A cushion, not shown, is fastened to the diagonal belt section 15, wherein the belt section 38 can alternatively be formed as a double-layered inflatable belt, at least in the region of the diagonal belt section 15. Alternatively, the retractor 3 can also be arranged at the upper end of the diagonal belt section 15, so that the vertical section 13 and the belt guide part 12 and possibly also the deflection device 11 can be dispensed with.

[0031] Figure 2 shows an enlarged section of the seat belt device 1 with the belt buckle 5 and the belt tongue 6 on a vehicle seat. The belt buckle 5 is attached to the holding element 8 on a displaceable structure of the seat structure, to which the gas generator 7 is also attached.Figures 3 and 4 show an enlarged view of the belt buckle 5 with the belt tongue 6 locked in it, viewed from different perspectives. The second ends of the belt strap sections 37 and 38, or the lap belt section 14 and the diagonal belt section 15, are attached separately to the belt tongue 6. The belt sections 37 and 38 thus form two independent restraint devices, which are coupled to one another via the belt tongue 6.

[0032] The belt buckle 5 is connected to a holding element 8, which can be fixed to the vehicle, in a tension-resistant manner via a pull cable 9. Furthermore, the gas generator 7 can also be fastened to the vehicle via a holding part 39, which can be seen in Figure 3, wherein the holding part 39 itself is fastened to the vehicle and the gas generator 7 is fastened to the holding part 39, for example, via a clamp fastening.

[0033] The belt tongue 6 is used to fasten the second ends of the belt sections 37 and 38, wherein the belt section 37 forming the lap belt section 14 extends laterally from the belt tongue 6 and the belt section 38 forming the diagonal belt section 15 extends on the front side of the belt tongue 6, as can be seen in Figure 4. Furthermore, a connection piece 17 is provided on the belt tongue 6, which is fl uidica I ly connected to the cushion provided on the diagonal belt section 15.

[0034] The belt buckle 5 comprises an insertion slot 19 for inserting a locking section 16 of the belt tongue 6, which is arranged parallel to a push button 24 provided on the belt buckle 5. The belt buckle 5 comprises a laterally extended housing, which is additionally used to accommodate a gas lance 18, as can be seen in Figure 5.

[0035] The belt buckle 5 comprises as a base component a carrier part 20, to which the pull rope 9 is attached in a tension-resistant manner, as can be seen in Figure 5. The carrier part 20 comprises a base plate 22, which is the carrier of a locking mechanism 23 known in the art. Furthermore, the carrier part 20 comprises a holding section 21 which extends outwards on one side of the base plate 22 and has two curved fixing sections, to which a guide tube 25 is fixed, in which the gas lance 18 is displaceable guided, as will be explained in more detail below. Thus, the guide tube 25 with the gas lance 18 arranged therein is in a direct positional relationship to the base plate 22 and thus to the carrier plate 20 as a whole.The belt tongue 6 comprises a tongue-shaped locking section 16 with a locking opening, by means of which it can be inserted into the insertion slot 19 of the belt buckle 5 during the fastening process and can be locked in the locking mechanism 23 in a known manner. A tubular connection piece 17 is provided adjacent to the locking section 16, which is in fluidic connection with the cushion on the diagonal belt section 15. The connection piece 17 is held on a carrier part, which is not shown, or is integrally formed therewith, on which the locking section 16 is also formed or held. The locking section 16 and the connection piece 17 are thus in a direct positional relationship with one another. Since the locking section 16 can be locked in only one position in the locking mechanism 23 of the belt buckle 5, the connection piece 17 is also defined in its alignment and position in the locking position of the belt tongue 6 with respect to the guide tube 25 and the gas lance 18 guided therein.

[0036] The connection piece 17 comprises a seal 28 at its end facing the gas lance 18. The belt buckle 5 is aligned with the locking mechanism 23 in such a way that the belt tongue 6 is aligned with the locking section 16 arranged in the locking position in such a way that the connection piece 17 is arranged with its end and the seal 28 arranged therein as close as possible to the guide tube 25 and the gas lance 18, wherein the connection piece 17 ideally slightly encompasses the gas lance 18 with its opening and is arranged without contact to the gas lance 18, so that the belt tongue 6 does not come to rest against the connection piece 17 on the gas lance 18 during the locking process.

[0037] In Fig. 6A, the connection piece 17 and the gas lance 18 can be seen as individual parts in a position before the activation of the gas generator 7. The guide tube 25 is fixed in a stationary position in the belt buckle 6 by a holding section 21 of the carrier plate 20, as described above, while the connection piece 17 is fixed in a stationary position in or on the belt tongue 6. The guide tube 25 is connected to the gas generator 7 via the filling hose 10 for the purpose of the flow. Alternatively, the gas generator 7 can also be connected directly to the guide tube 25, for example via a crimp connection. A direct connection of the gas generator 7 to the guide tube 25 would have the advantage that the gas generator 7 is also held on the belt buckle 5 by means of the guide tube 25 and thus requires no furtherattachment to the vehicle. The belt buckle 5 is thus manufactured, delivered and installed as an assembly with the gas generator 7.

[0038] The guide tube 25 is tubular and comprises an opening 45, which is narrowed by a radially inwardly directed annular edge 44, at its end facing the connection piece 17. A damper 29 is supported on the inside of this edge 44.

[0039] A second tube 26 is also provided on the guide tube 25, which is connected to the guide tube 25 on the inlet side of the guide tube 25 with respect to the gas flow generated by the gas generator 7 on its radially outer side and comprises a plurality of inflow openings 27. The second tube 26 comprises a cylindrical cavity 47. The gas lance 18 comprises a cylindrical pressure compartment 33 into which the second tube 26 projects before the gas generator 7 is activated. The second tube 26 thus forms a radially inner support for the gas lance 18.

[0040] Furthermore, the gas lance 18 comprises, at the end facing the gas generator 7, a radially outwardly projecting annular collar 31, which is dimensioned such that it extends as far as the inner wall of the guide tube 25 and delimits an annular pressure compartment 46 between the guide tube 25 and the second tube 26. In order to reduce leakage losses, an annular seal 32 is additionally provided on the outer wall 42 of the gas lance 18, on the side of the collar 31 facing away from the pressure compartment 46, which seal rests on the outside against the inside of the guide tube 25. The gas lance 18 abuts radially inside on the outer side of the second pipe 26, which thereby also performs a sealing function and seals the annular pressure compartment 46.

[0041] The gas lance 18 further comprises at its end facing the connection piece 17 a conical end face 40 tapering to a point and having a plurality of outlet openings 41 arranged therein uniformly distributed over the circumference. As a result, the gas stream flows out of the gas lance 18 as uniformly as possible without exerting recoil forces directed towards it. This means that the criterion of thrust neutrality can be fulfilled.

[0042] The seal 28 in the connection piece 17 is formed by an annular base body 35, with which it rests against the inner wall of the connection piece 17. The seal 28 further comprises anannular sealing lip 34 which projects radially inwards and forms a conically shaped sealing surface 36 which narrows in the direction of the inside of the connection piece 17.

[0043] The gas supply from the gas generator 7 to the cushion is described below with a more detailed description of the overflow of gas from the belt buckle 5 to the belt tongue 6.

[0044] When the gas generator 7 is activated and a gas flow is suddenly released as a result, the gas flow begins to flow in the direction of the arrow in Fig. 6B, wherein it first enters the opening of the guide tube 25 and enters the annular pressure compartment 46 between the inner wall of the guide tube 25 and the outer wall of the second tube 26. In this process, the gas stream drives the gas lance 18 over the frontal annular surface of the collar 31 in the direction of the connection pipe 17. During this outward movement, the gas lance 18 is guided on the second tube 26 and over the radial outer side of the collar 31 on the inner wall of the guide tube 25. In the further course of the movement, the gas lance 18 picks up with its free end, that is with the conical end face, through the seal 28 of the connection nozzle 17, wherein the seal 28 comes to rest with the sealing lip 34 on the outer wall 42 of the gas lance 18 in a sealing manner, as can be seen in Fig. 6C. The second tube 26 is dimensioned in length such that the gas lance 18 covers the second tube 26 and is guided on it until the seal 28 is fully in contact with the outer wall 42 of the gas lance 18 and the gas lance 18 has entered the pressure compartment 43 with the conical end face 40 with the outlet openings 41.

[0045] During the further extension movement of the gas lance 18, the latter loses the cover to the second tube 26, as can be seen in Fig. 6D, which loses therefore additionally its sealing function. This creates a flow connection between the annular pressure compartment 46 and the pressure compartment 33 in the gas lance 18, and the gas flow flows into the gas lance 18 in the illustrated directions of the arrows. From the pressure compartment 33 of the gas lance 18, the gas flow then passes through the outlet openings 41 on the front side 40 of the gas lance 18 into the pressure compartment 43 of the connection nozzle 17 and then into the cushion.Finally, the further extension movement of the gas lance 18 takes place up to the end position shown in Fig. 6E, in which the gas lance 18 comes to rest against the damper 29 with the seal 32. The damper 29 is of elastic design and thus forms an elastic stop for limiting the extension movement of the gas lance 18. Furthermore, the damper 29 is designed in such a way that it expands radially outwards and radially inwards as a result of the elastic deformation, so that it then comes into contact with the gas lance 18 and the guide tube 25 and clamps the gas lance 18 in the end position. In addition, the damper 29 contributes to increasing the sealing effect and to reducing leakage losses of the gas flow.List of reference signs

[0046] 1 seat belt device

[0047] 2 seat belt

[0048] 3 first retractor

[0049] 4 second retractor

[0050] 5 belt buckle

[0051] 6 belt tongue

[0052] 7 gas generator

[0053] 8 holding element

[0054] 9 tensioning cable

[0055] 10 filling hose

[0056] 11 deflection device 12 belt guide part

[0057] 13 vertical section

[0058] 14 lap belt section

[0059] 15 diagonal belt section 16 locking section

[0060] 17 connection piece 18 gas lance

[0061] 19 insertion slot

[0062] 20 carrier plate

[0063] 21 holding section

[0064] 22 base plate

[0065] 23 locking mechanism 24 pushbutton

[0066] 25 guide tube

[0067] 26 second tube

[0068] 27 inflow opening

[0069] 28 seal

[0070] 29 dampertube section

[0071] collar

[0072] second seal pressure compartment sealing lip

[0073] base body

[0074] sealing surface

[0075] belt section

[0076] belt section

[0077] holding part

[0078] front side

[0079] outlet opening outer wall

[0080] pressure compartment edge

[0081] opening

[0082] pressure compartment cavity

Claims

Claims:

1. Seat belt device (1) having-a seat belt (2),-at least one retractor (3, 4),-a belt buckle (5) that can be fixedly attached to the vehicle,-a belt tongue (6) which divides the seat belt (2) into a diagonal belt section (15) and a lap belt section (14) and can be locked in a tension-resistant manner by means of a locking section (16) in a locking mechanism (23) of the belt buckle (5),-an inflatable cushion arranged on the diagonal belt section (15),-a gas generator (7) for inflating the cushion, wherein-a gas lance (18) having an outlet opening (41) and fluidica I ly connected to the gas generator (7) is provided on the belt buckle (5), and-a connection piece (17) is provided on the belt tongue (6), which connection piece is in fluidic communication with the gas bag,characterized in that-a guide tube (25) is provided on the belt buckle (5), in which the gas lance (18) is displaceable guided, and-the connection piece (17) comprises a tubular pressure compartment (42) which is connected to the cushion in terms of flow and comprises a seal (28) at the end facing the gas lance (18), wherein-the gas lance (6) is fixed in the guide tube (25) by a holding part and / or a frictional force up to a limit force to be overcome, wherein-the holding part and / or the frictional force are dimensioned such that the limit force to be overcome is exceeded when the gas generator (7) is activated by the gas flow and pressure produced thereby and the gas lance (18) is displaced to such an extent that it passes with the outlet opening (41) the seal (28) of the connection piece (17), and the seal (28) an outer wall (42) of the gas lance (18) in a sealing manner.

2. Seat belt device (1) according to claim 1, characterized in that-a stop limiting the sliding movement of the gas lance (18) is provided on the gas lance (18) and / or on the guide tube (25).

3. Seat belt device (1) according to claim 2, characterized in that-the stop is formed by a damper (29).

4. Seat belt device (1) according to claim 3, characterized in that-the damper (29) is of annular design.

5. Seat belt device (1) according to any one of claims 3 or 4, characterized in that-the damper (29) is of elastic design and, in the stop position of the gas lance (18), comes to rest in a sealing manner against the outer wall (42) of the gas lance (18) by means of elastic deformation.

6. Seat belt device (1) according to any one of claims 1 to 5, characterized in that-the seal (28) comprises a resilient sealing lip (34) having a sealing surface (36) which narrows conically in the direction of the sliding movement of the gas lance (18).

7. Seat belt device (1) according to any one of claims 1 to 6, characterized in that-the gas lance (18) comprises, at its end facing the connection piece (17), a conically shaped end side (40) in which the outflow opening (41) is arranged.

8. Seat belt device (1) according to claim 7, characterized in that-a plurality of outflow openings (41) are provided, which are uniformly distributed over the circumference of the conical end face (40).

9. Seat belt device (1) according to any one of claims 1 to 8, characterized in that -a second tube (26) is provided in the guide tube (25) and has a smaller outside diameter than the inside diameter of the guide tube (25) in order to form an annular pressure compartment (46), and- the gas lance (18) comprises a pressure compartment (33) into which the second tube (26) projects, wherein- the gas lance (18) seals off the annular pressure compartment (46) and is guided in a sealing manner on the second tube (26).

10. Seat belt device (1) according to claim 9, characterized in that-the second tube (26) is dimensioned in length such that the gas lance (18) loses the sealing guide on the second tube (26) during the extension movement after it passes with the outlet opening (41) the seal (28) of the connection piece (17), and the seal (28) comes into sealing contact with an outer wall (42) of the gas lance (18).

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