Safety belt system with an inflatable gas bag

Abstract

The invention relates to a safety belt device (1) comprising a safety belt (2), at least one belt retractor (3, 4), a belt buckle (5) that can be fixed to the vehicle, a belt tongue (6) dividing the safety belt (2) into a diagonal belt section (15) crossing the chest of an occupant when fastened and a lap belt section (14) crossing the occupant's pelvis when fastened, which can be locked tensile-resistant with a locking section (16) in a locking mechanism (23) of the belt buckle (5), an inflatable gas bag arranged on the diagonal belt section (15), a gas generator (7) for inflating the gas bag, wherein a gas lance (18) is provided on the belt buckle (5) which is fluidly connected to the gas generator (7), and a connecting nozzle (17) which is fluidly connected to the gas bag is provided on the belt tongue (6).and the gas lance (18) and the connecting nozzle (17) are arranged by their arrangement on the belt buckle (5) and on the belt tongue (6) in a predetermined target position such that they are arranged without contact with each other in a position of the belt tongue (6) locked in the belt buckle (5).

Description

The invention relates to a safety belt device with an inflatable gas bag having the features of the preamble of claim 1. Seat belt systems in motor vehicles have long been state of the art and serve to restrain the occupant in an accident to prevent serious injuries. Three-point seat belt systems have proven particularly effective; these feature a seat belt that, at one end, can be attached to the vehicle structure or the seat itself via a vehicle-mounted end fitting on one side of the seat, and at the other end, can be wound up via a belt retractor that is also vehicle-mounted to the seat or the vehicle structure on the same side of the seat.Furthermore, a belt tongue is slidably guided on the seat belt, which can be locked in a belt buckle attached on the other side of the vehicle seat to achieve the 3-point geometry and, in the locked position, divides the seat belt into a diagonal belt section extending from the belt buckle diagonally across the occupant's chest to the belt retractor and a lap belt section extending from the belt buckle to the end fitting across the occupant's pelvis. Furthermore, it is known to provide an inflatable gas bag on the diagonal belt section, which is inflated in front of the occupant's chest in the event of an accident. German patent application DE 10 2021 111 522 A1 discloses a restraint system with such a safety belt device, in which a gas generator is provided on the belt buckle. Upon activation, this gas generator instantly releases a gas flow to inflate the gas bag. An inflation hose is provided to establish a fluid connection between the gas generator located on the belt buckle and the gas bag located on the diagonal belt section. The patent application does not disclose how this fluid connection between the gas generator and the inflation hose is achieved. Another safety belt device with a belt retractor having the features of the preamble of claim 1 is known, for example, from US 6 168 196 B1. One problem is that the gas generator associated with the seatbelt buckle is considered stationary due to its placement on the buckle, while the gas bag associated with the diagonal belt section is not stationary due to the movement of the diagonal belt section. Therefore, the fluid-flow connection must be re-established every time the seatbelt is fastened and must be achieved via a detachable interface. Against this background, the invention is based on the objective of providing a safety belt device with an inflatable gas bag and a gas generator arranged on the belt buckle, which is designed in such a way that the inflation process is as reliable as possible even when external forces are applied. To solve the problem, a safety belt device with the features of claim 1 is proposed according to the invention. Further preferred developments can be found in the dependent claims, the figures and the associated description. According to the basic concept of the invention, it is proposed that the gas lance or a part fluidically connected to the gas lance be spring-loaded, wherein the spring load is directed in the direction of the longitudinal axis of the gas lance and is blocked by a releasable locking device. Due to the spring load on the gas lance or the part fluidly connected to it, this part can perform slight spring movements, e.g., to compensate for external mechanical influences. Furthermore, the spring load can be additionally blocked by a releasable locking device, which is only unlocked when the gas generator is activated, so that the gas lance or the part only performs a directed movement when the releasable locking device is released. The gas lance and the connecting piece are each preferably formed by dimensionally stable pipe sections. These pipe sections are dimensionally stable and, in the fixed position, each form a dimensionally stable counterpart for the other part. Due to their dimensional stability, the pipe sections, when fixed to the belt tongue and the belt buckle itself, form very precisely aligned and, in particular, stationary flow connections for transferring the gas flow. It is further proposed that the gas lance and the connection fitting be arranged concentrically to each other in the locked position of the belt tongue. This concentric arrangement of the connection fitting to the gas lance enables a homogeneous flow path with a gas flow distributed as uniformly as possible across the cross-sectional area, and consequently, the momentum forces acting on the gas lance and the connection fitting. It is further proposed that the gas lance and the connecting piece be aligned along their longitudinal axes when the belt tongue is locked. This alignment of the connecting piece and the gas lance ensures that the gas flow is directed without deflections, thus minimizing stress on the belt buckle and the belt tongue when the gas generator is activated. It is further proposed that the gas lance and the connecting piece be aligned parallel to the insertion direction of the belt tongue into the belt buckle. This alignment of the gas lance and the connecting piece guides them towards each other along their longitudinal axes during insertion, reducing the distance between them until they are finally in the intended position, with the belt tongue locked, and are arranged without contact with each other with the smallest possible gap. The invention is explained in more detail below with reference to various exemplary embodiments. Figure 1 shows a safety belt assembly according to the invention; Figure 2 shows an enlarged section of a vehicle seat with an occupant and a belt buckle with a belt tongue of the safety belt assembly according to the invention locked therein; Figure 3 shows the belt buckle with the belt tongue as a separate component; Figure 4 shows an enlarged section of the belt tongue with the belt buckle in various views; Figure 5 shows the belt tongue and the belt buckle as separate components; Figure 6 shows the belt buckle in various views with only one housing half; Figure 7 shows the belt buckle and the belt tongue with their individual components in an exploded view before assembly; Figure 8 shows the housing of the belt buckle with a gas lance and a connecting piece of the belt tongue in various enlarged views; and Figures 9, 10, 11, 12 to 13 show the belt buckle assembly as a separate component.13 a belt tongue with a belt buckle in sectional view in different positions of the insertion movement and before and after activation of a gas generator in various embodiments of the safety belt device. Fig. 1 shows a safety belt device 1 according to the invention, comprising a safety 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. The deflection device 11 and the belt guide part 12 each have a belt slot or a belt guide opening through which the safety belt 2 is guided and / or deflected to achieve a predetermined position. For this purpose, the deflection device 11 and the belt guide part 12 are fixedly attached to a vehicle seat, a B-pillar, a C-pillar, or another point in the vehicle structure. The safety belt 2 comprises two separate webbing sections 37 and 38, the first ends of which can each be wound onto one of the belt retractors 3 or 4. The belt retractors 3 and 4 are themselves fixedly attached to the vehicle structure or to the vehicle seat itself on one side of a vehicle seat and, in a locked position, form a fixed connection between the ends of the webbing sections 37 and 38 and the vehicle structure in a known manner. The other ends of the webbing sections 37 and 38 are attached to the belt tongue 6, which, to achieve the 3-point geometry, can be locked in the belt buckle 5, which is attached to the vehicle structure or to the vehicle seat itself on the other side of the vehicle seat. The belt buckle 5 is connected via a flexible pull cord 9 to a vehicle-mounted retaining element 8. Furthermore, a gas generator 7 is provided, which is attached to the vehicle via a retaining part 39 (shown in Fig. 3) and is fluidically connected via a flexible filling hose 10 to a connection nozzle 34 of the belt buckle 5 (shown, for example, in Fig. 7). In the locked position of the belt tongue 6, the safety belt 2 has a 3-point geometry. One webbing section 37 forms a lap belt section 14 that crosses the occupant's pelvis, and the other webbing section 38 forms a diagonal section 15 from the belt tongue 6 to the deflection device 11 and a vertical section 13 from the deflection device 11 via the belt guide 12 to the belt retractor 3. A gas bag (not shown) is attached to the diagonal section 15. Alternatively, the webbing section 38 can also be designed as a double-layered inflatable belt, at least in the area of ​​the diagonal section 15. Alternatively, the belt retractor 3 can also be arranged at the upper end of the diagonal section 15, so that the vertical section 13, the belt guide 12, and, if applicable, the deflection device 11 are omitted. Figure 2 shows an enlarged section of the safety belt assembly 1 with the buckle 5 and the tongue 6 on a vehicle seat. The buckle 5 is attached to a sliding part of the seat structure by the retaining element 8, 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 within it, viewed from different perspectives. The webbing sections 37 and 38, or the lap belt section 14 and the diagonal belt section 15, are attached separately to the belt tongue 6 at their second ends. The webbing sections 37 and 38 thus each form independent restraint devices, which are coupled to each other via the belt tongue 6. The seatbelt buckle 5 is connected to a vehicle-mountable retaining element 8 via a pull cable 9. Furthermore, the gas generator 7 can also be mounted to the vehicle via a retaining part 39, which can be seen in Fig. 3. The retaining part 39 itself is mounted to the vehicle, and the gas generator 7 is attached to the retaining part 39, for example, by means of a clamp. The belt tongue 6 serves to fasten the second ends of the webbing sections 37 and 38, with the webbing section 37, forming the lap belt section 14, extending laterally from the belt tongue 6 and the webbing section 38, forming the diagonal belt section 15, extending forward from the belt tongue 6, as can be seen in Figures 4 and 5. A connecting piece 17 is also provided on the belt tongue 6, which is fluidically connected to the gas bag provided on the diagonal belt section 15. The belt buckle 5 has 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 has a laterally extended housing 25, which also serves to accommodate a gas lance 18, which is connected to the connection nozzle 34 at its underside. In Fig. 6, the seatbelt buckle 5 is shown from the front and rear, without either half of the housing 25 shown in Fig. 7. The seatbelt buckle 5 has a support part 20 as its base component, to which the pull rope 9 is securely attached. The support part 20 has a base plate 22, which carries a locking mechanism 23 known in the prior art. Furthermore, the support part 20 has a retaining section 21 extending outwards from the base plate 22 on one side, with two curved fixing sections to which the gas lance 18 and / or the connecting piece 34 of the seatbelt buckle 5 are fixed. Figure 7 shows the belt tongue 6 and the belt buckle 5 with their individual parts before assembly. The belt tongue 6 has a tongue base body 27 with a tongue-shaped locking section 16, two parallel retaining arms 29 projecting to one side, an opening 28, and a laterally projecting retaining section 36. The opening 28 is semicircularly curved on one side and serves to secure the second end of the diagonal belt section 15. The retaining section 36 is formed by curved fixing arms that encompass the connecting piece 17 and clamp it in place. The belt tongue 6 also has a housing 26, which is composed of two housing halves and encompasses the tongue base body 27 and the connecting piece 17 on its outer sides. One of the housing halves additionally has a lateral opening 40 through which the space between the retaining arms 29 of the tongue base body 27 is exposed.The pelvic belt section 14 is fixed at its second end to form a loop 31, whereby a sleeve may additionally be provided in the loop 31 for stiffening. The pelvic belt section 14 is inserted into the opening 40 with the loop 31 for fixation to the belt tongue 6 and then connected to the tongue base body 27 in a tensile-resistant manner by laterally inserting a fixing pin 30 through the openings of the retaining arms 29 and the loop 31. The belt buckle 5 also has a housing 25 formed by two housing halves, which includes the support part 20, the locking mechanism 23, the gas lance 18, and the connecting piece 34. The gas lance 18 is additionally enclosed by a fixing sleeve 32 and is supported against the housing 25 by a compression spring 33. Figure 8 shows the connecting piece 17 of the belt tongue 6 (not shown) and the housing of the belt buckle 5 with the gas lance 18 before and after establishing a fluid connection. The gas lance 18 has a plurality of radially evenly distributed outlet openings 41 at its end facing the connecting piece 17. The connecting piece 17 has a radially widened annular space, which is arranged such that, when attached to the gas lance 18, it surrounds the outlet openings 41 of the gas lance 18. Thus, when the gas generator 7 is activated, the gas flow passes through the gas lance 18, via the outlet openings 41, into the annular space and from there through the connecting piece 17 into the gas bag of the diagonal belt section 15.Since the outlet openings 41 are radially oriented and evenly distributed around the circumference, the belt buckle 5, and thus the entire safety belt assembly 1, meets the requirements for thrust neutrality, so that the belt buckle 5 and the safety belt assembly 1 do not perform any uncontrolled movements in the event of unintentional activation of the gas generator 7, e.g., during transport. Furthermore, to improve the flow connection and increase efficiency, an additional ring seal 42 is provided, which seals the annular space in the connection nozzle 17 against the interior of the housing of the belt buckle 5. In principle, the belt tongue 6 and the belt buckle 5 are designed and arranged such that, when the seatbelt is fastened—that is, when the belt tongue 6 is inserted with the locking section 16 into the insertion slot 19 of the belt buckle and the locking section 16 engages in the locking mechanism 23—they are aligned with each other in such a way that the connecting piece 17 of the belt tongue 6, in the locked position of the belt tongue 6, is positioned as close as possible to the gas lance 18 without touching it. This has the advantage that the connecting piece 17 and the gas lance 18 are not subjected to any mechanical stress during each locking and unlocking process of the belt tongue 6. Furthermore, the locking and unlocking process cannot be blocked or inhibited by any possible contact between the connecting piece 17 and the gas lance 18.Another advantage of this contactless arrangement is that the belt tongue 6 can thereby make slight movements for alignment and yielding due to tensile forces exerted via the belt sections 37 and 38, so that constraint forces and tensions in the gas lance 18 and in the connecting nozzle 17 are avoided. The alignment or arrangement of the belt tongue 6 relative to the belt buckle 5 is defined by the fact that the belt tongue 6, with the locking section 16, is positioned in the locking mechanism 23 in a predefined position in the locked position. In this position, a blocking lever of the locking mechanism 23 engages in the opening of the locking section 16, thereby blocking the belt tongue 6 from being pulled out of the belt buckle 5. The locking section 16 is an integral part of the tongue base body 27, to which the retaining section 36 with the fixing arms for holding the connecting piece 17 is also integrally formed.This means that the connecting piece 17 held on the holding section 36 is arranged via the fixing arms of the holding section 36 in a maximum positional accuracy corresponding to a predetermined position, which depends solely on the form accuracy of the holding section 36 and the locking section 16, i.e., the form accuracy of the tongue base body 27. Since the locking mechanism 23 of the belt buckle 5 is held on the base plate 22 of the support part 20 and is thus defined in its position, and the gas lance 18 itself or via the connecting piece 34 is held on the retaining section 21 provided integrally on the support plate 20, the gas lance 18 is in turn aligned with maximum positional accuracy with respect to a predetermined target position to the locking mechanism 23, the locking section 16 of the belt tongue 6 held therein in the locked position and thus also to the connecting piece 17 of the belt tongue 6 held on the retaining section 36. Due to the one-piece formation of the retaining section 36 on the tongue base body 27 and the retaining section 21 on the support plate 20, the connecting stub 17 of the belt tongue 6 and the gas lance 18 of the belt buckle 5 are precisely fixed to the parts which also define the alignment of the belt tongue 6 to the belt buckle 5 in the locked position.The position and orientation of the connecting nozzle 17 in relation to the gas lance 18 in the locked position of the belt tongue 6 is subject to a maximally short tolerance chain and is in particular independent of the assembly and tolerances of various individual parts of the belt buckle 5 and the belt tongue 6. The gas lance 18 and the connecting nozzle 17 are aligned such that their longitudinal axes are parallel to the insertion direction of the belt tongue 6 and preferably parallel to the longitudinal axis of the locking section 16 in the locked position of the belt tongue 6, so that during the locking movement of the belt tongue 6, at least during the final phase, their longitudinal axes are moved towards each other, reducing their distance, until they are finally arranged in the desired position with the smallest possible distance to each other and without contact. The connecting piece 17 of the belt buckle 5 is tubular in shape and has a conically expanding funnel-shaped end section 43 on the side facing the belt buckle 5, with which the connecting piece 17 of the belt tongue 6 concentrically encompasses the gas lance 18 in the locked position of the belt tongue 6. The connecting piece 17 and the gas lance 18 are each designed as dimensionally stable tubular bodies, arranged concentrically to each other with longitudinal axes parallel to each other. Furthermore, the gas lance 18 and the connecting piece 17 are aligned such that their longitudinal axes are parallel to the insertion direction of the belt tongue 6 into the belt buckle 5, i.e., parallel to the longitudinal direction of the locking section 16 in the locked position of the belt tongue 6. Figures 9, 10, 11, 12 to 13 show various embodiments of a safety belt device according to the invention in different positions of a belt buckle 5 and a belt tongue 6 relative to each other in sectional views. On the left in each figure is a position of the belt tongue 6 with the locking section 16 inserted but not yet locked. In the second view from the left, the belt tongue 6 is shown with the locking section 16 locked, i.e., in a position locked in the belt buckle 5. In the second view from the right, the position of the belt tongue 6 is shown in an early phase of an accident, in which the gas generator 7 is not yet activated, but the diagonal belt section 15 is already exerting a tensile force on the belt tongue 6.In the right-hand illustration, the belt tongue 6 can be seen in a position in which the gas generator 7 is activated, and a gas flow passes over the gas lance 18 into the connection nozzle 17 and over into the gas bag on the diagonal belt section 15. Figure 9 shows a first embodiment of a safety belt device according to the invention, in which the gas lance 18 in the belt buckle 5 is additionally spring-loaded via the spring 33. Furthermore, the gas lance 18 is designed at its flow inlet side such that it can be slightly compressed, allowing pressure to build up in the gas lance 18. The gas lance 18 has an additional sliding cap 44 with outlet openings at its outlet side, which is held on the gas lance 18 in such a way that, when a predetermined axial force is exceeded, it moves relative to the gas lance 18 into the position shown on the right in Figure 9. The predetermined axial force is designed such that it is only built up when the gas generator 7 is activated by the pressure generated in the gas lance 18, for which purpose the gas lance 18 can be additionally compressed.The cap 44 of the gas lance 18 is then moved so that it lies flat against a counter surface of the connection nozzle 17, whereby the outlet openings of the cap 44 cover one or more openings of the connection nozzle 17, so that the gas from the gas lance 18 passes into the connection nozzle 17 and from there into the gas bag on the diagonal belt section 15 with as little loss as possible. In the second embodiment shown in Fig. 10, the gas lance 18 has an extendable lifting tube section 45 with corresponding outlet openings, which is driven to extend from the gas lance 18 when the gas generator 7 is activated. The lifting tube section 45 is held in the gas lance 18 such that it can only move in the direction of the connection nozzle 17 when a predetermined axial force is exceeded. The axial force to be exceeded is designed such that it is only exceeded by the activation of the gas generator 7. The lifting tube section 45 is then moved until its end face rests against a surface of the connection nozzle 17, and the gas flow passes from the outlet openings of the lifting tube section 45 into the connection nozzle 17 with minimal leakage losses.In addition to the highest possible efficiency, this has the advantage that the gas flow does not escape laterally into the belt tongue 6 and the belt buckle 5 and stress the individual parts of the same or strike the occupant's hip laterally. Figure 11 shows a third embodiment of a safety belt device according to the invention, in which a sliding connector 46 is provided in the gas lance 18. The connector 46 is spring-loaded by a spring 33 towards an initial position, which can be seen in the left-hand illustration of Figure 11. When the belt tongue 6 is locked, it first contacts the end face of the connector 46 with the connecting piece 17. During the further locking movement of the belt tongue 6, the connector 46 is pushed into the gas lance 18 by compressing the spring 33, as can be seen in the second illustration from the left. If, in the early stages of an accident, the tensile force exerted on the belt tongue 6 via the diagonal belt section 15 increases, the belt tongue 6 is extended a short distance in the direction of tension, as can be seen in the second illustration from the right. Due to the spring tension, the connecting piece 46 is also extended while resting against the connecting sleeve 17. When the gas generator 7 is activated in this position, the connecting piece 46 is no longer displaced, and the gas flows through the gas lance 18 and the connecting piece 46 into the connecting sleeve 17 and from there into the gas bag on the diagonal belt section 15. Figure 12 shows another alternative embodiment in which the gas lance 18 is enclosed at the gas outlet end by a tube section 47, which is supported on the gas lance 18 by a spring 49. The tube section 47 has a plurality of outlet openings 47 evenly distributed around its circumference on its end face. Due to their uniform arrangement, these outlet openings, like the outlet openings 41 on the gas lance 18 itself, ensure that the seat belt assembly 1 is designed to be shear-neutral overall. When the belt tongue 6 is inserted into the buckle 5, the connecting piece 17 is placed with its end face onto the tube section 47 and then, during the further insertion movement of the belt tongue 6, compresses the spring 49, displacing the tube section 47 until it reaches the position shown in the second illustration from the left in Figure 12. In the event of an accident, the belt tongue 6 is subjected to stress and is pulled a short distance away from the belt buckle 5 by the connecting piece 17. The pipe section 47 also performs this displacement movement due to the spring tension. When the gas generator 7 is activated, the position of the gas lance 18, the pipe section 47, and the connecting piece 17 no longer changes, and the gas flows from the gas lance 18 through the outlet openings 41, the pipe section 47, and the outlet openings 48 into the connecting piece 17. Figure 13 shows a further embodiment of the invention, in which a spring-loaded piston 50, with a plurality of outlet openings 51 arranged at its end face, is provided in the gas lance 18. The piston 50 is only driven to an extension movement into an activation position by the activation of the gas generator 7 and the gas flow thereby released. In this position, the outlet openings 51 are in fluidic contact with the connecting nozzle 17, as can be seen in the right-hand view of Figure 13.

Claims

Seat belt assembly (1) comprising: - a seat belt (2), - at least one belt retractor (3, 4), - a belt buckle (5) that can be fixed to the vehicle, - a belt tongue (6) dividing the seat belt (2) into a diagonal belt section (15) and a lap belt section (14), which can be locked tensile-resistant with a locking section (16) in a locking mechanism (23) of the belt buckle (5), - an inflatable gas bag arranged on the diagonal belt section (15), - a gas generator (7) for inflating the gas bag, wherein - a gas lance (18) is provided on the belt buckle (5) which is fluidly connected to the gas generator (7), and - a connecting nozzle (17) which is fluidly connected to the gas bag is provided on the belt tongue (6), and - the gas lance (18) and the connecting nozzle (17) are connected by their arrangement on the The seat belt buckle (5) and the seat belt tongue (6) are arranged in a predetermined target position such thatthat they are arranged without contact to each other in a position of the belt tongue (6) locked in the belt buckle (5), characterized in that the gas lance (18) or a part fluidically connected to the gas lance (18) is spring-loaded, wherein the spring load is directed in the direction of the longitudinal axis of the gas lance (18) and is blocked by a releasable locking device. Safety belt device (1) according to claim 1, characterized in that the gas lance (18) and the connecting nozzle (17) are each formed by dimensionally stable tube sections. Safety belt device (1) according to claim 2, characterized in that the gas lance (18) and the connecting nozzle (17) are arranged concentrically to each other in the locked position of the belt tongue (6). Safety belt device (1) according to one of claims 2 or 3, characterized in that the gas lance (18) and the connecting nozzle (17) are aligned with their longitudinal axes in the locked position of the belt tongue (6). Safety belt device (1) according to claim 4, characterized in that the gas lance (18) and the connecting nozzle (17) are aligned parallel to an insertion direction of the belt tongue (6) into the belt buckle (5).

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