Belt tensioning arrangement for a safety belt system in a vehicle

Abstract

The invention relates to a belt tensioning arrangement (1) for a safety belt system, comprising a belt retractor (5) and a hydraulic spring arrangement (10) by which the tensioning of a corresponding webbing (3) can be adjusted between a minimum and a maximum value, wherein the hydraulic spring arrangement (10) comprises a hydraulic cylinder (11) with a pressure chamber (12) in which a sliding piston (13) movable between a starting position and an end position, with a piston plunger (14) and a connecting rod (17), and a spring device (18) pre-tensioning the piston (13) are arranged, wherein a hydraulic pressure acting on the piston (13) can be adjusted between a maximum pressure value in the starting position of the piston (13), from which a maximum spring pre-tension of the spring device (18) results, and a minimum pressure value in the end position of the piston (13).from which a minimum spring preload of the spring device (18) results, wherein the webbing (3) has a minimum tension in the initial position of the piston (13) and a maximum tension in the final position, wherein an evaluation and control unit (19) is designed to adjust the hydraulic pressure via a hydraulic valve (16) and a pressure generator (P) depending on a current operating state of the vehicle, and a vehicle with at least one such belt tensioning arrangement (1).

Description

[0001] The invention relates to a belt tensioning device for a seat belt system in a vehicle. Furthermore, the invention relates to a vehicle with at least one such belt tensioning device for a seat belt system.

[0002] Seatbelt pretensioners for vehicle safety belt systems are available in numerous variations. These systems are typically designed as three-point belts, comprising a buckle, buckle tongue, webbing, and retractor. The webbing is anchored to the vehicle body at three points. In the event of hard braking or a collision, the webbing is pretensioned by the pretensioner. Pyrotechnically actuated pretensioners can be used for this purpose.

[0003] A disadvantage of this system is that it can only be used once. Furthermore, the seatbelt tension may remain after an accident. In such cases, emergency services may have to cut the seatbelt to free the occupants. Particularly in vehicles where the occupants are upside down, self-extrication without assistance is nearly impossible due to the seatbelt tension and the occupants' own weight.

[0004] From DE 199 35 248 C1, a safety belt system for motor vehicles is known, comprising a safety belt retractor that guides the safety belt webbing and is height-adjustable in a substantially vertical sliding guide arranged on the vehicle frame, a locking device that locks the safety belt retractor in a functional starting position in the sliding guide and opens the locking device in the event of a collision, a safety belt tensioning mechanism which, when the locking device is open, displaces the safety belt retractor in the sliding guide in the opposite direction to the direction of the safety belt webbing and the collision-related tensile forces acting on it until the safety belt webbing is sufficiently tensioned, and a safety belt force limiting mechanism which limits the tensioning of the safety belt webbing generated by the safety belt tensioning mechanism in a predetermined manner.A reset mechanism, which returns the seatbelt retractor to its functional starting position in the guide after the collision has ended and no further tensile forces are acting on the seatbelt webbing, locks it into place. The seatbelt tensioning mechanism is designed with at least one spring device located between the guide and the seatbelt retractor. In the functional starting position of the seatbelt retractor, this spring is pre-tensioned such that, in the event of a collision, the retractor, triggered by the locking device, is moved within the guide, tensioning the seatbelt, until a balance of forces is reached with the tensile forces acting on the seatbelt webbing, thus limiting the seatbelt force. The reset mechanism is electrically and / or pneumatically and / or hydraulically operated.

[0005] From DE 10 2005 014 521 A1, an occupant protection system in a motor vehicle is known, comprising a seatbelt tensioner for an occupant in a seat of the vehicle, which includes a tensioning device. Upon receiving an accident signal generated by a sensor, the tensioning device briefly tightens the belt with a strong force by releasing the energy stored in an energy storage device. The tensioning device is designed as a reversible energy storage device, the energy content of which can be restored after its activation by applying mechanical energy.

[0006] The invention is based on the objective of providing a belt tensioning arrangement for a safety belt system in a vehicle, as well as a vehicle with at least one such belt tensioning arrangement, which can be easily and quickly adapted to different operating conditions of the vehicle.

[0007] This problem is solved by a belt tensioning arrangement for a safety belt system in a vehicle with the features of claim 1 and by a vehicle with the features of claim 10. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0008] To provide a belt tensioning device for a vehicle's seat belt system that can be easily and quickly adapted to various vehicle operating conditions, a belt retractor and a hydraulic spring assembly operatively connected to the belt retractor are provided. This assembly allows the tension of a corresponding belt to be adjusted between a minimum and a maximum value. The hydraulic spring assembly comprises a hydraulic cylinder with a pressure chamber. Within the pressure chamber of the hydraulic cylinder are a sliding piston with a piston pin and a connecting rod, which moves between a starting position and an end position, and a spring assembly with at least one spring element that pre-tensions the piston.A hydraulic pressure in the pressure chamber, acting against a spring force of the spring assembly on the piston, is adjustable between a maximum pressure value in the piston's initial position, resulting in maximum spring preload of the spring assembly, and a minimum pressure value in the piston's final position, resulting in minimum spring preload of the spring assembly. The webbing exhibits minimal tension in the piston's initial position and maximum tension in its final position. An evaluation and control unit is designed to adjust the hydraulic pressure in the pressure chamber of the hydraulic cylinder, via at least one hydraulic valve and a pressure generator, depending on the current operating state of the vehicle.

[0009] Furthermore, a vehicle with at least one such belt tensioning arrangement for a seat belt system is proposed.

[0010] By arranging the at least one spring element of the spring device in the pressure chamber of the hydraulic cylinder, the at least one spring element is advantageously protected from external influences. The at least one spring element can preferably be designed as a helical spring.

[0011] A seat belt system, as defined below, comprises a buckle, a buckle tongue, a webbing, and a retractor. In a three-point seat belt system, the webbing is anchored to the vehicle body at three points. On the driver's side, the webbing's end fitting is typically attached to the lower part of a B-pillar. The second attachment point is the buckle, usually located on the seat. When the seat belt is fastened, the webbing is connected to the buckle via the buckle tongue. The third attachment point is the retractor, also located in the lower part of the B-pillar. A guide point for the three-point seat belt system is generally integrated into a height adjuster at the top of the B-pillar. When the seat belt is fastened, the buckle tongue engages with the buckle and locks into place.In this case, the webbing runs vertically from the end fitting to the deflection point and then diagonally over the occupant's shoulder to the buckle and from there horizontally in the occupant's pelvic area to the belt retractor.

[0012] In an advantageous embodiment of the belt tensioning device, the evaluation and control unit can be further configured to adjust, during normal vehicle operation, the hydraulic pressure in the hydraulic cylinder's pressure chamber and the resulting spring force of the spring assembly acting on the belt retractor, such that the corresponding tensioning of the belt causes it to rest against the body of a buckled occupant. A reduction in the hydraulic pressure in the pressure chamber and a resulting reduction in the spring preload of the spring assembly can increase the spring force of the spring assembly acting on the belt retractor and the tensioning of the belt. Conversely, an increase in the hydraulic pressure in the pressure chamber and a resulting increase in the spring preload of the spring assembly can reduce the spring force of the spring assembly acting on the belt retractor and the tensioning of the belt.This allows the tightening of the webbing to be adapted to the current operating condition of the vehicle particularly easily and quickly by adjusting or regulating the hydraulic pressure in the pressure chamber of the hydraulic cylinder.

[0013] In a further advantageous embodiment of the belt tensioning arrangement, the evaluation and control unit can be further configured to, upon activation and receipt of a trigger signal via the at least one hydraulic valve, abruptly reduce the hydraulic pressure in the pressure chamber of the hydraulic cylinder to the minimum pressure value and the resulting spring preload of the spring device to the minimum spring preload, so that the released energy of the spring device and the resulting spring force acting on the belt winding device can achieve maximum tensioning of the belt. Preferably, the at least one hydraulic valve can connect the pressure chamber to a pressureless hydraulic fluid reservoir during activation. Such a hydraulic fluid reservoir can, for example, be used as a reservoir for the hydraulic fluid of the hydraulic spring arrangement.

[0014] In a further advantageous embodiment of the belt tensioning device, the evaluation and control unit can be further designed to increase the hydraulic pressure in the pressure chamber and the resulting spring preload of the spring device after activation, and to reduce the spring force of the spring device acting on the belt retractor and the tension of the belt. Such controlled "release" of the belt after an accident can advantageously facilitate the extrication of the occupant without cutting the belt.

[0015] In a further advantageous embodiment of the belt tensioning arrangement, the activation case can be triggered, for example, if a deceleration of the vehicle exceeds a first threshold, or if an acceleration of the vehicle exceeds a second threshold, or if an accident is detected.

[0016] In a further advantageous embodiment of the belt tensioning device, the belt retractor can comprise a belt retractor and a motion converter coupled to the connecting rod, which converts the translational movement of the connecting rod into a rotary movement of the belt retractor. For this purpose, the motion converter can, for example, comprise a link chain or rack connected to the connecting rod, which meshes with a toothed section attached to the belt retractor, so that the translational movement of the connecting rod is converted into the rotary movement of the belt retractor.

[0017] In a further advantageous embodiment of the belt tensioning arrangement, the evaluation and control unit can be further configured to acquire and evaluate at least one piece of information about the current position of the piston and / or the distance traveled by the piston and / or the tension force currently acting on the belt via at least one sensor unit. The evaluation and control unit can use one or more of these acquired pieces of information to adjust or regulate the hydraulic pressure in the pressure chamber of the hydraulic cylinder in order to adapt the belt tension to the current operating condition of the vehicle.

[0018] The advantages and preferred embodiments described for the belt tensioning arrangement according to the invention also apply to the vehicle according to the invention.

[0019] The features and combinations of features mentioned above in the description, as well as those subsequently mentioned in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments that are not explicitly shown or explained in the figures, but which can be derived and generated from the explained embodiments by separate combinations of features, are also to be considered as encompassed and disclosed by the invention.

[0020] An embodiment of the invention is shown in the drawings and is explained in more detail in the following description. In the drawings, identical reference numerals denote components or elements that perform the same or analogous functions. The drawings show: Fig. 1 a schematic representation of an embodiment of a belt tensioning arrangement according to the invention for a safety belt system in a vehicle in a starting position; Fig. 2 a schematic representation of the belt tensioning arrangement according to the invention for a safety belt system in a vehicle made of Fig. 1 in an intermediate position during normal operation of the vehicle; Fig. 3 a schematic representation of the belt tensioning arrangement according to the invention for a safety belt system in a vehicle made of Fig. 1 and Fig. 2 in a final position during an activation event; and Fig. 4 a schematic representation of the belt tensioning arrangement according to the invention for a safety belt system in a vehicle made of Fig. 1 to 3 in an intermediate position after an activation event.

[0021] As from Fig. As can be seen in Figures 1 to 4, the illustrated embodiment of a belt tensioning arrangement 1 according to the invention for a safety belt system in a vehicle comprises a belt retractor 5 and a hydraulic spring arrangement 10 operatively connected to the belt retractor 5, by means of which the tension of a corresponding belt 3 can be adjusted between a minimum and a maximum value. The hydraulic spring arrangement 10 includes a hydraulic cylinder 11 with a pressure chamber 12. Within the pressure chamber 12 of the hydraulic cylinder 11, there is a sliding element between a Fig. 1 shown starting position and one in Fig. Figure 3 shows a movable piston 13 with a piston plunger 14 and a connecting rod 17, and a spring device 18 with at least one spring element that pre-tensions the piston 13. A hydraulic pressure in the pressure chamber 12, acting against a spring force of the spring device 18 on the piston 13, is adjustable between a maximum pressure value in the initial position of the piston 13, resulting in a maximum spring pre-tension of the spring device 18, and a minimum pressure value in the final position of the piston 13, resulting in a minimum spring pre-tension of the spring device 18. The webbing 3 has a minimum tension in the initial position of the piston 13 and a maximum tension in the final position of the piston 13.An evaluation and control unit 19 is designed to adjust the hydraulic pressure in the pressure chamber 12 of the hydraulic cylinder 11 depending on the current operating state of the vehicle via at least one hydraulic valve 16 and a pressure generator P (not shown in detail).

[0022] As from Fig. As can be seen in Figures 1 to 4, the belt retractor 5 in the illustrated embodiment comprises a belt retractor 7 and a motion converter 9 coupled to the connecting rod 17, which converts the translational movement of the connecting rod 17 into a rotary movement of the belt retractor 7. For this purpose, the motion converter 9 in the illustrated embodiment of the belt tensioning device 1 comprises a link chain 9A connected to the connecting rod 17, which meshes with a toothed section 9B attached to the belt retractor 7, so that the translational movement of the connecting rod 17 is converted into the rotary movement of the belt retractor 7. Of course, suitable alternative embodiments of the motion converter 9 are also possible. For example, instead of the link chain, the motion converter 9 can comprise a rack which is connected to the connecting rod 17.

[0023] For setting or regulating the hydraulic pressure in the pressure chamber 12 of the hydraulic cylinder 11 and the resulting tightening of the belt 3, the evaluation and control unit 19 is further designed to acquire and evaluate at least one sensor unit (not shown in detail) that provides information about the current position of the piston 13 and / or about the distance traveled by the piston 13 and / or about the tension force currently acting on the belt 3.

[0024] As from Fig. As can be seen in Figures 1 to 4, the spring device 18 in the illustrated embodiment comprises only one spring element designed as a helical spring 18A. The helical spring 18A is arranged in a right-hand part of the hydraulic cylinder 11 and is supported on a side of the piston ram 14 facing away from the motion converter 9 and on the base of the hydraulic cylinder 11. The piston 13 in the right-hand part of the hydraulic cylinder 11 has a larger cross-section than the connecting rod 17, which runs in a left-hand part of the hydraulic cylinder 11. At least one compensating opening 15 is provided in the piston ram 14, which connects the right-hand part of the hydraulic cylinder 11 with the left-hand part of the hydraulic cylinder 11.

[0025] In the illustrated embodiment, the evaluation and control unit 19 is further developed in a Fig. In the normal operation of the vehicle shown in Figure 2, the hydraulic pressure in the pressure chamber 12 of the hydraulic cylinder 11 and the resulting spring force of the spring device 18 acting on the belt retractor 5 are to be adjusted such that the corresponding tensioning of the belt 3 causes the belt 3 to rest against the body of a buckled occupant. A reduction in the hydraulic pressure in the pressure chamber 12 and a resulting reduction in the spring preload of the spring device 18 increases the spring force of the spring device 18 acting on the belt retractor 5 and the tensioning of the belt 3. An increase in the hydraulic pressure in the pressure chamber 12 and a resulting increase in the spring preload of the spring device 18 reduces the spring force of the spring device 18 acting on the belt retractor 5 and the tensioning of the belt 3.

[0026] Furthermore, the evaluation and control unit 19 is further developed, in a Fig.In the activation scenario shown in Figure 3, upon receiving a trigger signal via the at least one hydraulic valve 16, the hydraulic pressure in the pressure chamber 12 of the hydraulic cylinder 11 is abruptly reduced to the minimum pressure value, and the resulting spring preload of the spring device 18 is reduced to the minimum spring preload, so that the released energy content of the spring device 18 and the resulting spring force of the spring device 18 acting on the belt winding device 5 cause the maximum tensioning of the belt 3. Preferably, in the activation scenario, the at least one hydraulic valve 16 connects the pressure chamber 12 to a pressureless hydraulic fluid reservoir R (not shown in detail).

[0027] Furthermore, the evaluation and control unit 19 is designed to increase the hydraulic pressure in the pressure chamber 12 and a resulting spring preload of the spring device 18 after the activation event, and to reduce the spring force of the spring device 18 acting on the belt winding device 5 and the tightening of the belt 3.

[0028] In the illustrated embodiment of the belt tensioning device 1, activation is triggered when the vehicle's deceleration exceeds a first threshold, when the vehicle's acceleration exceeds a second threshold, or when an accident is detected. Preferably, a higher-level control unit (not shown) generates the corresponding trigger signal and outputs it to the evaluation and control unit 19. To generate the trigger signal, the control unit evaluates, for example, information from environmental sensors and internal acceleration sensors. REFERENCE MARK LIST 1 Belt tensioning arrangement 3 webbing 5 Belt retractor 7 seatbelt retractors 9 motion converters 9A Link chain 9B gearing 10 Hydraulic spring assembly 11 hydraulic cylinders 12 Printing chamber 13 pistons 14 piston rams 15 Compensation opening 16 Hydraulic valve 17 Connecting rod 18 Spring device 18A Coil spring 19 Evaluation and control unit P printer R Hydraulic fluid reservoir

Claims

[1] Belt tensioning arrangement (1) for a seat belt system in a vehicle, comprising a belt retractor (5) and a hydraulic spring arrangement (10) operatively connected to the belt retractor (5), by means of which a tensioning of a corresponding belt webbing (3) can be adjusted between a minimum value and a maximum value, wherein the hydraulic spring arrangement (10) comprises a hydraulic cylinder (11) with a pressure chamber (12), wherein in the pressure chamber (12) of the hydraulic cylinder (11) a sliding piston (13) movable between a starting position and an end position with a piston plunger (14) and a connecting rod (17) and a spring device (18) with at least one spring element, which preloads the piston (13), are arranged, wherein a hydraulic pressure acting against a spring force of the spring device (18) on the piston (13) in the pressure chamber (12) is between a maximum pressure value in the starting position of the piston (13),from which a maximum spring preload of the spring device (18) results, and a minimum pressure value in the end position of the piston (13) is adjustable, from which a minimum spring preload of the spring device (18) results, wherein the webbing (3) has a minimum tension in the starting position of the piston (13) and a maximum tension in the end position of the piston (13), wherein an evaluation and control unit (19) is designed to adjust the hydraulic pressure in the pressure chamber (12) of the hydraulic cylinder (11) via at least one hydraulic valve (16) and a pressure generator (P) depending on a current operating state of the vehicle. [2] Belt tensioning arrangement (1) according to claim 1, characterized by, that the evaluation and control unit (19) is further designed to adjust, in normal operation of the vehicle, the hydraulic pressure in the pressure chamber (12) of the hydraulic cylinder (11) and the resulting spring force of the spring device (18) acting on the belt winding device (5) so that the corresponding tightening of the belt webbing (3) causes the belt webbing (3) to lie against the body of a buckled occupant. [3] Belt tensioning arrangement (1) according to claim 2, characterized by, that a reduction of the hydraulic pressure in the pressure chamber (12) and a resulting reduction of the spring preload of the spring device (18) increases the spring force of the spring device (18) acting on the belt winding device (5) and the tightening of the webbing (3), and an increase of the hydraulic pressure in the pressure chamber (12) and a resulting increase of the spring preload of the spring device (18) reduces the spring force of the spring device (18) acting on the belt winding device (5) and the tightening of the webbing (3). [4] Belt tensioning arrangement (1) according to one of claims 1 to 3, characterized by, that the evaluation and control unit (19) is further designed, in an activation case after receiving a trigger signal via the at least one hydraulic valve (16), to reduce the hydraulic pressure in the pressure chamber (12) of the hydraulic cylinder (11) abruptly to the minimum pressure value and the resulting spring preload of the spring device (18) to the minimum spring preload, so that a released energy content of the spring device (18) and the resulting spring force of the spring device (18) acting on the belt winding device (5) cause the maximum tightening of the belt (3). [5] Belt tensioning arrangement (1) according to claim 4, characterized by , that the at least one hydraulic valve (16) connects the pressure chamber (12) to a pressureless hydraulic fluid reservoir (R) in the event of activation. [6] Belt tensioning arrangement (1) according to claim 4 or 5, characterized by, that the evaluation and control unit (19) is further designed to increase the hydraulic pressure in the pressure chamber (12) and a resulting spring preload of the spring device (18) after the activation case and to reduce the spring force of the spring device (18) acting on the belt winding device (5) and the tightening of the belt (3). [7] Belt tensioning arrangement (1) according to any one of claims 4 to 6, characterized by , that the activation event can be triggered if a deceleration of the vehicle exceeds a first threshold, or an acceleration of the vehicle exceeds a second threshold, or an accident is detected. [8] Belt tensioning arrangement (1) according to any one of claims 1 to 7, characterized by , that the belt winding device (5) comprises a belt winder (7) and a motion converter (9) coupled to the connecting rod (17), which converts the translational movement of the connecting rod (17) into a rotary movement of the belt winder (7). [9] Belt tensioning arrangement (1) according to any one of claims 1 to 8, characterized by , that the evaluation and control unit (19) is further designed to acquire and evaluate at least one sensor unit, at least one piece of information about the current position of the piston (13) and / or about a distance traveled by the piston (13) and / or about a tension force currently acting on the belt (3). [10] Vehicle with at least one belt tensioning arrangement (1) for a safety belt system as designed according to any one of claims 1 to 9.

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