Safety belt system for a vehicle

Abstract

Safety belt assembly for a vehicle seat (1), comprising a safety belt which can be attached to the vehicle via a fitting (9), wherein the safety belt device has a belt force limiter (15) with which, in the event of a belt extension being blocked due to a vehicle deceleration (a), the belt force (F) acting on the vehicle occupant or on the fitting (9) G ) can be limited, wherein the belt force limiter (15) interacts with a rope element (11) led to the fitting (9), and wherein the belt force limiter (15) has at least one pair of clamping elements through whose clamping gap the rope element (11) is guided and whose clamping elements (17, 19) are clamped with a clamping force (F K ) are pressed against each other, and where the clamping force (F K ) is dimensioned such that the clamping body pair releases a rope extension (Δl) provided the belt force (F G ) the clamping force (F K exceeds, wherein it is provided that the belt force limiter (15) has an actuating unit (20) by means of which the clamping force (F) acting on the rope element (11) K ) is adjustable depending on occupant-specific parameters of the vehicle occupant secured by the safety belt on the vehicle seat (1), and / or where it is provided that during vehicle deceleration (a) the belt force acting on the vehicle occupant or on the fitting (9) (F G ) correlates with the vehicle occupant mass, characterized by that the actuating unit (20) has a cam guide (21) in which a clamping element (19) is adjustable in the direction of the clamping gap.

Description

[0001] The invention relates to a safety belt device for a vehicle according to the preamble of claim 1.

[0002] Such a safety belt system can, for example, consist of a three-point safety belt with a lap belt section and a shoulder belt section. When the safety belt is fastened, the lap belt section extends laterally across the vehicle between an inner and an outer attachment point. The inner attachment point, located at lap level, is typically designed to be detachable and is implemented by a belt tongue attached to the safety belt and a vehicle-mounted buckle that engages with it. An outer attachment point, located approximately at shoulder height, is usually implemented by a guide fitting around which the shoulder belt section is routed to a retractor installed in a vehicle pillar.

[0003] A generic seat belt device for a vehicle is known from DE 10 2014 226 083 A1. When fastened, the seat belt tongue is detachably connected to a vehicle-mounted buckle. The seat belt device has a belt force limiter at the buckle. If the belt extension is blocked due to vehicle deceleration, the belt force acting on the vehicle occupant or on the buckle can be limited by means of the belt force limiter. The belt force limiter interacts with a cable element leading to the buckle.

[0004] The seat belt force limiter must be designed to accommodate different occupant masses. For example, the force limiter must provide a high counterforce for a heavy man (25th percentile male) to achieve optimal energy absorption in a crash. Conversely, the force limiter must provide a significantly lower counterforce for a small woman (5th percentile female).

[0005] Against this background, the belt force limiter in DE 10 2014 226 083 A1 features an actuator that uses sensors to detect occupant-specific parameters, such as the vehicle occupant mass. Based on these detected occupant-specific parameters, the actuator can adjust the counterforce provided by the belt force limiter. The actuator is implemented as a costly electronic component that interacts with the belt force limiter via complex electrical interfaces.

[0006] DE 195 11 457 A1 discloses a force limitation device in an occupant restraint system. DE 299 09 114 U1 discloses a seat belt system for vehicles. DE 195 46 280 A1 discloses an exemplary seat belt device. DE 100 52 688 A1 discloses an exemplary seat belt device.

[0007] The object of the invention is to provide a safety belt system for a vehicle which is structurally simpler compared to the prior art.

[0008] The object of the invention is achieved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

[0009] The invention relates to a seat belt assembly for a vehicle in which, when fastened, the seat belt is detachably connected to a vehicle-mounted buckle via its belt tongue. The seat belt assembly includes a belt force limiter, which limits the belt force acting on the vehicle occupant or the buckle when belt extension is blocked due to vehicle deceleration. According to the invention, the belt force limiter is positioned in the area of ​​the buckle so that it interacts with a cable element leading to the buckle. For ease of use, the belt force limiter has at least one pair of clamping elements. The cable element is guided through a clamping gap in the pair of clamping elements. The cable element is pressed between the two clamping elements with a predetermined preload.The preload corresponds to a clamping force with which the two clamping elements press against the cable element at their clamping gap. The clamping force, or preload, is designed so that, during normal driving, cable extension of the cable element leading to the buckle is blocked. The pair of clamping elements only releases the cable when the belt force acting on the buckle exceeds the clamping force. In this case, the buckle can be displaced by a length offset to limit the belt force acting on the vehicle occupant.

[0010] It should be emphasized that the invention is not limited to application in a seatbelt buckle. Rather, the invention relates to a seatbelt that can generally be attached to a fitting. The fitting can preferably be designed as a vehicle-mounted seatbelt buckle into which a belt tongue, held by the seatbelt, can be detachably inserted. Alternatively, the fitting can be an end fitting attached to the vehicle body, to which the seatbelt is attached. For the sake of clarity, the following aspects of the invention are described specifically for a fitting designed as a seatbelt buckle.

[0011] Enhanced functionality is achieved when the belt force limiter function is performed based on the current occupant-specific parameters of the vehicle occupant secured to the vehicle seat by the seat belt. Against this background, the belt force limiter, according to the invention, has an actuating unit by means of which the clamping force acting on the cable element can be adjusted based on occupant-specific parameters, in particular based on the current mass of the vehicle occupant. Alternatively or additionally, according to the invention, during vehicle deceleration, the belt force acting on the vehicle occupant or on the belt buckle correlates with the mass of the vehicle occupant. This means that a high belt force acts on the buckle for a heavy man (95th percentile male), while a correspondingly lower belt force acts on the buckle for a small woman (5th percentile female).

[0012] It is particularly preferred if the actuating unit enables self-regulating adjustment of the clamping force, i.e., without external electronic signal processing and control. In such a case, the force limiter function can be implemented without the need for electrical components and interfaces, which is advantageous from a manufacturing perspective. According to the invention, the actuating unit has a cam guide in which one of the clamping elements is adjustable. The other clamping element, on the other hand, can be stationary or pre-tensioned towards the clamping gap. When the belt force is applied to the vehicle occupant or the belt buckle, the adjustable clamping element is subjected to an additional force component that correlates with the belt force. This additional force component increases the clamping force acting between the clamping elements.Since the magnitude of the additional force component is directly proportional to the belt force and thus to the vehicle occupant mass, a force limiting function that reacts independently to the respective vehicle occupant mass is provided.

[0013] In a preferred implementation of the force limiter function, the rope element can be deflected from the buckle around the adjustable clamping body at a wrap angle and subsequently guided through the clamping gap. A movement stop with a larger cross-sectional area than the rope element itself can be formed at its end. During rope extension, this stop can be brought into contact with the clamping body pair, thus limiting the maximum rope extension.

[0014] The guide mechanism preferably includes a pivot lever, at the end of which, furthest from the pivot axis, the adjustable clamping element is mounted. During manufacturing, the clamping elements can be pressed into the rope element with a precisely defined pressure using a pressing process. This presses the rope element between the two clamping elements with a predetermined preload.

[0015] Exemplary embodiments of the invention are described below with reference to the accompanying figures. These show: Fig. 1 a safety belt system in normal driving operation; Fig. 2. the safety belt system in the event of a crash; and Fig. 3 in a view according to the Fig. 1 a safety belt device according to a second embodiment.

[0016] In the Fig. Figure 1 shows the seat belt assembly in a state where it is fastened to the vehicle occupant. The seat belt assembly comprises a three-point seat belt with a lap belt section 3 and a shoulder belt section 5. When fastened, the lap belt section 3 of the seat belt extends in the transverse direction y of the vehicle between an inner and an outer attachment point. The inner attachment point, located approximately at pelvic level, is in the Fig. 1. This is achieved by a belt tongue 7 attached to the seat belt and a vehicle-mounted buckle 9 that interacts with it. An attachment point (not shown), located approximately at shoulder height, is exemplified by a deflection fitting (not shown) around which the shoulder belt section 5 is guided to a retractor, for example, installed in a vehicle pillar. In the event of significant vehicle deceleration a, for example, due to an accident, a winding drum in the retractor is locked to prevent the belt from extending. This results in a belt force F. G ( Fig. 2) on the vehicle occupants or on the seatbelt buckle 9.

[0017] In the Fig. A wire rope 11 is attached to the seatbelt buckle 9 and is guided in a loop around an eyelet (not shown) inside the seatbelt buckle 9. The wire rope 11 protrudes from the seatbelt buckle 9 and extends over a free rope length to a vehicle-mounted seatbelt buckle fitting 13, which is permanently installed in the vehicle.

[0018] Within the belt buckle fitting 13, a belt force limiter 15 is arranged, which is described below: Accordingly, the belt force limiter 15 has a pair of clamping elements consisting of an upper, stationary clamping roller 17 and a lower, adjustable clamping roller 19, which is adjustable by means of a cam guide 21. The cam guide 21 is located in the Fig. 1 and Fig. 2 is implemented as a pivot lever, which is pivotally mounted about a pivot axis 23. The adjustable clamping roller 19 is rotatably mounted at the end of the lever furthest from the pivot axis. The stationary clamping roller 17 is also rotatably mounted in the belt buckle fitting 13.

[0019] According to the Fig. 1. Starting from the buckle 9, the wire rope 11 is deflected around the adjustable clamping roller 19 with a wrap angle α and subsequently guided through the clamping gap. At the end of the wire rope 11, a movement stop 25 with a cross-sectional area larger than that of the wire rope 11 is formed.

[0020] The wire rope 11 is pressed between the two clamping rollers 17, 19 with a predetermined preload F0. This ensures that the adjustable clamping roller 19 is pressed into its lower position in the normal operating state, i.e., when the belt extension is not blocked. The preload F0 is in the Fig. 1 identical to a clamping force F K , by means of which the two clamping rollers 17, 19 act on the wire rope 11. The clamping force F KThe design is such that, during normal driving operation, the extension of the wire rope 11 from the belt force limiter 15 is blocked. The clamping element pair only releases the rope extension when the belt force F acting on the belt buckle 9 is exceeded. G the clamping force F K exceeds. In this case, the belt buckle 9 is offset by a length Δl ( Fig. 2) shifted to limit the belt force F acting on the vehicle occupant 1 G to achieve.

[0021] The core of the invention consists in the fact that the adjustable clamping roller 19 and the pivot lever 21 form a self-regulating actuating unit 20 of the belt force limiter 15. With the aid of the actuating unit 20, a force limiting function is provided that reacts independently to the mass of the vehicle occupants, as shown below with reference to the Fig. 2 is described: According to the Fig. 2 In a crash, a vehicle deceleration a acts on the (not shown) vehicle occupant. This blocks the retractor, thus preventing the seat belt from extending. In this case, the belt force F acting on the vehicle occupant and on the seat belt buckle 9 builds up G on. When applying the belt force F G The adjustable clamping roller 19 with an additional force component F is attached to the belt buckle 9. Z acted upon, which is subjected to the belt force F G correlated. Under the influence of the additional force component F Z The pivot lever 21 is moved from its lower position ( Fig. 1) by a swivel angle β ( Fig. 2) shifted upwards towards the clamping gap. In the event of a crash, the clamping force F therefore shifts. K from the preload F0 and from the additional force component F Z together.

[0022] The magnitude of the additional force component F K is directly proportional to the belt force F Gand thus to the current vehicle occupant mass. This means that for a small woman (95% female) with a correspondingly reduced mass, the clamping force F acting between the clamping rollers 17, 19 K is reduced accordingly. In contrast, for a heavy man (that is, a 95% man) with a correspondingly large mass, the clamping force F acting on the clamping rollers 17, 19 is K The clamping force F is increased accordingly. This ensures that, regardless of the occupant's mass, the maximum possible displacement path Δl of the vehicle occupant can be utilized in the event of a crash, regardless of whether the occupant is small and light or large and heavy. K This is done without additional sensors or other electrical components or interfaces.

[0023] According to the invention, a reduced force limitation can be achieved for a woman with 5% disability, with maximum possible forward displacement, thereby reducing the crash energy in the vehicle occupant to the lowest possible level. In contrast, a high force limitation with maximum possible forward displacement is achievable for a man with 95% disability, but without forward impact. The load in the event of a crash is also reduced to the maximum for this vehicle occupant.

[0024] It should be emphasized that the invention is not limited to the clamping rollers 17, 19. Rather, general profile elements can also be used instead, which can be, for example, round, curved or semicircular.

[0025] In the Fig. Figure 3 shows a further embodiment of the invention. The basic structure and function of the device shown in the Fig. The belt force limiter 15 shown in section 3 corresponds to the one in the Fig. 1 and Fig. 2 belt force limiters shown 15. In contrast to the Fig. 1 and Fig. 2 is in the Fig. 3 of the belt force limiter 15 is not designed with a swivel lever 21, but rather with a linear guide 27 along which the bearing pins 28 of the adjustable clamping roller 19 can be displaced in the direction of the clamping gap. Reference symbol list 1 vehicle seat 3. Pelvic belt component 5 Shoulder strap portion 7 Belt tongue 9 Seatbelt buckle 11 Wire rope 13 Seatbelt buckle fitting 15 belt force limiters 17 stationary clamping roller 19 adjustable clamping rollers 20 actuators 21 Backstage Tour 23 Swivel axis 25 Movement stop 27 Linear guide 28 bearing journals F G Belt force F0 Preload F K Clamping force FZ Additional force component Δl rope extension α Wrap angle β Swivel angle

Claims

Safety belt assembly for a vehicle seat (1), comprising a safety belt which can be attached to the vehicle via a fitting (9), wherein the safety belt assembly has a belt force limiter (15) with which, in the event of a belt extension being blocked due to a vehicle deceleration (a), the forces acting on the vehicle occupants orThe belt force (FG) acting on the fitting (9) can be limited, wherein the belt force limiter (15) interacts with a rope element (11) guided to the fitting (9), and wherein the belt force limiter (15) has at least one pair of clamping elements through whose clamping gap the rope element (11) is guided and whose clamping elements (17, 19) are pressed against each other with a clamping force (FK), and wherein the clamping force (FK) is dimensioned such that the pair of clamping elements releases a rope extension (Δl) if the belt force (FG) exceeds the clamping force (FK), wherein it is provided that the belt force limiter (15) has an adjusting unit (20) by means of which the clamping force (FK) acting on the rope element (11) can be adjusted depending on occupant-specific parameters of the vehicle occupant secured with the seat belt on the vehicle seat (1), and / or wherein it is provided that that during vehicle deceleration (a) the forces acting on the vehicle occupants orThe belt force (FG) acting on the fitting (9) is correlated with the mass of the vehicle occupants, characterized in that the actuating unit (20) has a cam guide (21) in which a clamping element (19) is adjustable in the direction of the clamping gap. Safety belt device according to claim 1, characterized in that when the belt force (FG) is applied to the fitting (9) the adjustable clamping element (19) is subjected to an additional force component (FZ) corresponding to the belt force (FG), which presses the adjustable clamping element (19) against the other clamping element (17), thereby increasing the clamping force (FK) acting between the clamping elements (17, 19). Safety belt device according to claim 1 or 2, characterized in that the rope element (11) is deflected from the fitting (9) with a wrap angle (α) around the adjustable clamping body (19) and is subsequently guided through the clamping gap, and that a movement stop (25) with a cross-sectional area larger than that of the rope element (11) is formed at the end of the rope element, which can be brought into contact with the clamping body pair during rope extension (Δl) in order to limit the rope extension. Safety belt device according to claim 3, characterized in that the wrapping angle (α) is open in the direction towards the fitting (9) or towards the front of the vehicle, so that the rear circumferential section of the adjustable clamping body (19) facing away from the fitting (9) is wrapped, while the front circumferential section of the adjustable clamping body (19) facing the fitting (9) is not wrapped. Safety belt device according to claim 2, characterized in that the cam guide (21) has a pivot lever, at the end of the lever furthest from the pivot axis the adjustable clamping body (19) is mounted, so that when the additional force component (FZ) acts, the adjustable clamping body (19) can be pivoted with a pivot angle (β) in the direction of the clamping gap. Safety belt device according to claim 2, characterized in that the cam guide has a linear guide (27) in which the adjustable clamping body (19) is guided in a linearly adjustable manner, so that when the additional force component (FZ) acts, the adjustable clamping body (19) can be adjusted with a linear movement in the direction of the clamping gap. Safety belt device according to claim 2, characterized in that the rope element (17) is pressed between the two clamping bodies (17, 19) with a predetermined preload (F0) which corresponds to the clamping force (FK) in normal driving operation, i.e. with unblocked belt extension, and that in the event of a crash or a greater vehicle deceleration (a) the clamping force (FK) is composed of the preload (F0) and the additional force component (FZ). Safety belt device according to one of the preceding claims, characterized in that the clamping elements (17, 19) are clamping rollers or round or semi-circular profile elements.

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