Safety belt device for a vehicle and vehicle

Abstract

A safety belt device for a vehicle comprising a webbing, a belt retractor, a deflection element (1) for deflecting the webbing, and an activatable belt tensioner with a force-limiting unit for force-limited tightening of the applied webbing when a vehicle occupant who has fastened the belt shifts forward, wherein a bolt (3) of the deflection element (1), over which the webbing is deflected and which is normally mounted in a rotationally and positionally fixed manner, is rotatably mounted when the belt tensioner is activated and when a torque acting on the bolt (3) exceeds a predetermined value, characterized in that the bolt (3) is force- and / or positively coupled to at least one component (2) which is normally mounted in a rotationally fixed manner, and the component (2) has at least one predetermined breaking point (S).which breaks when the specified value with respect to the torque is exceeded and, in the broken state, releases a rotational movement of the bolt (3), and the component (2) has a rotationally fixed section (A1) and a section (A2) which rotates with the bolt (3) after the at least one predetermined breaking point (S) has broken.

Description

[0001] The invention relates to a safety belt device for a vehicle comprising a webbing, a belt retractor, a deflection element for redirecting the webbing, and an activatable belt tensioner with a force-limiting unit for force-limited tightening of the fastened webbing when a vehicle occupant, who has fastened the belt, shifts forward. The invention further relates to a vehicle with such a safety belt device.

[0002] From EP 0 487 760 A1, a seat belt restraint system for a vehicle is known. The seat belt restraint system is equipped with a vehicle-sensitive or belt-sensitive self-locking belt retractor and a downstream belt clamping device. To activate the belt clamping device with minimal belt pull-out and to protect the belt from damage during a clamping process, the clamping force exerted on the belt by the belt clamping device is limited to a predetermined value.

[0003] German patent DE 41 35 111 A1 further discloses a safety belt device for a vehicle with a webbing that is deflected by a deflecting element. Under normal operating conditions, a bolt of the deflecting element is mounted to prevent rotation and positional instability. When a torque acting on the bolt exceeds a predetermined value, it is mounted to allow rotation.

[0004] DE 10 2005 049 893 A1 further discloses a safety belt device for a vehicle with a webbing which is deflected at a deflecting element, wherein the deflecting element has at least one predetermined breaking point which breaks when the specified value with respect to the torque is exceeded and releases a rotational movement of the deflecting element in the broken state.

[0005] The invention is based on the objective of specifying a novel safety belt device for a vehicle and a vehicle with such a safety belt device.

[0006] The problem is solved according to the invention by a safety belt device which has the features specified in claim 1, and by a vehicle which has the features specified in claim 5.

[0007] A safety belt device for a vehicle comprises a webbing, a belt retractor, a deflection element for redirecting the webbing, and an activatable belt tensioner with a force-limiting unit for force-limited tightening of the applied webbing when a vehicle occupant, who has fastened the belt, shifts forward. According to the invention, a bolt of the deflection element, over which the webbing is deflected and which is normally fixed in rotation and position, is rotatably mounted when the belt tensioner is activated and a torque acting on the bolt exceeds a predetermined value.

[0008] Normal operation refers in particular to driving conditions in which the vehicle is not subjected to collision-related accelerations.

[0009] By means of such a designed deflection element, it is possible to reduce belt friction forces on the deflection element's bolt when the occupant shifts forward, particularly when the specified value is exceeded. Since the bolt is mounted in a rotationally and positionally fixed manner during normal operation of the seat belt device, especially by means of a fixed bearing, unwanted noise, such as rattling, during vehicle operation can be largely eliminated. Thus, no disturbing noises occur during vehicle operation due to a so-called loose bearing. The bolt's fixed bearing is selectively released to become a loose bearing, allowing the bolt to rotate, thereby reducing the frictional forces acting between the belt webbing and the deflection element, particularly between the belt webbing and the bolt.This makes it possible to design a torsion bar to limit the belt force when tightening the webbing, dimensioned accordingly.

[0010] In one embodiment, the bolt is coupled to at least one component that is normally fixed against rotation by force and / or form locking, and this component has at least one predetermined breaking point. This component coupled to the bolt serves to transform the fixed bearing into a floating bearing, allowing the bolt to rotate. This reduces the frictional forces between the webbing and the bolt, i.e., the belt guide element. The predetermined breaking point breaks when the specified torque value is exceeded, releasing the bolt into rotation. This reduces the frictional forces between the webbing and the guide element during belt tensioning with force limitation. The bolt can rotate according to a tensile force acting on the webbing, so that the webbing essentially does not slide along the bolt, thus preventing the frictional forces from occurring.

[0011] In one possible embodiment, the component has a section that is fixed against rotation and a section that rotates with the bolt after at least one predetermined breaking point has broken. After the at least one predetermined breaking point has broken, the component has the two sections in the form of two parts, so that the bolt of the deflection element can rotate and a floating bearing is formed. The resulting rotational movement of the bolt reduces the frictional forces between the webbing and the bolt.

[0012] In another embodiment, at least one predetermined breaking point is designed as a material weakening between the rotationally fixed section and the rotating section. This material weakening is designed such that it breaks when a specific torque acting on the bolt, and thus on the component, is reached due to frictional forces resulting from tensile forces. This allows the bolt to rotate freely, reducing the frictional forces between the webbing and the bolt.

[0013] Even if the material weakening, i.e. the predetermined breaking point, fails prematurely, this does not result in any functional impairment of the deflection element, the belt tensioning and the force limitation during belt tensioning.

[0014] In another possible embodiment, the component is made of at least one type of plastic with a predetermined plastic deformability. This plastic deformability is specifically defined with respect to the predetermined breaking point, allowing the sections of the component to position themselves relative to each other until the predetermined breaking point yields and breaks. This enables the bolt to rotate, reducing frictional forces between the webbing and the bolt. During normal operation, however, the bolt is rigidly mounted to the component, thus largely preventing noise from the deflection element, particularly while the vehicle is in motion.

[0015] Furthermore, the invention relates to a vehicle with a seat belt device which, according to the invention, is designed such that the bolt of the deflection element, over which the belt is deflected and which is normally mounted in a rotationally and positionally fixed manner, is rotatably mounted when the belt tensioner is activated and when a torque acting on the bolt exceeds a predetermined value. The bolt is then rotatably mounted so that the frictional forces between the bolt and the belt, particularly when the belt tensioner is activated, can be reduced.

[0016] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0017] This shows: Fig. 1. Schematic perspective view of a deflection element for a webbing of a vehicle safety belt device, Fig. 2 schematically another perspective view of the deflection element, Fig. 3 schematically a side view of the deflection element and Fig. 4 schematically a component for reducing frictional forces.

[0018] Corresponding parts are marked with the same reference symbols in all figures.

[0019] Fig. Figure 1 shows a perspective view of a deflection element 1 for deflecting a belt (not shown in detail) of a safety belt device of a vehicle.

[0020] Fig. Figure 2 shows another perspective view of the deflection element 1, whereas in Fig. 3 a side view of the deflection element 1 and in Fig. Figure 4 shows a component 2 for reducing frictional forces between the webbing and a bolt 3 of the deflection element 1.

[0021] The safety belt device, which includes the deflection element 1 and the webbing, further comprises a belt retractor and an activatable belt tensioner with a force limiting unit in the form of a torsion bar for force-limited tightening of the applied webbing in the event of a forward displacement of an occupant of the vehicle.

[0022] For example, it is a pyrotechnically triggered and / or electrically motor-driven seatbelt tensioner.

[0023] A seatbelt pretensioner is designed, particularly in the event of a vehicle collision, to tighten the seatbelt so that it fits relatively closely to the occupant's body and the occupant participates in the vehicle's overall deceleration relatively early. To limit the maximum force exerted on the occupant by the seatbelt's tightening during a collision, a force limiting unit, also known as a seatbelt force limiter, is provided.

[0024] The force limiting unit is designed as a torsion bar, which twists in the opposite direction to the winding direction of the belt retractor to limit the tension force acting on the belt webbing. This reduces the restraining force exerted on the occupant by the belt, particularly to biomechanically tolerable limits. This force limiting, for example, largely prevents rib fractures in the occupant.

[0025] Typically, the deflection element 1 for redirecting the seat belt, for example within an integrated seat belt or concealed by a B-pillar trim panel of the vehicle, includes a bolt 3 along which the seat belt slides and is deflected, particularly when unwinding from or retracting onto a belt retractor. The bolt 3 is fixed to a retaining element 4 of the deflection element 1 in a rotationally and positionally fixed manner. If the bolt 3 is not fixed to the retaining element 4, there is a risk of disruptive noise, especially rattling, during normal operation of the seat belt system, particularly while the vehicle is driving. Usually, the bolt 3 is rigidly mounted to the retaining element 4. This prevents unwanted noise; however, the fixed mounting of the bolt 3 results in comparatively high frictional forces between it and the seat belt, especially when the belt tensioning mechanism is activated.These frictional forces acting on the deflection of the webbing significantly determine the dimensioning of the torsion bar as a force limiting unit of the safety belt device.

[0026] To form the deflection element 1 so that during the belt tensioning, which is triggered pyrotechnically and / or electrically, the frictional forces between the bolt 3 and the belt are reduced, the deflection element 1 is designed as described below.

[0027] The bolt 3 is fixedly arranged on the retaining element 4, with the component 2 being arranged at one end 3.1 of the bolt 3. In particular, the bolt 3 is fixedly mounted on the retaining element 4 by means of the component 2, which is arranged on the outside of a leg 4.1 of the retaining element 4 and is positively and non-positively connected to the end 3.1 of the bolt 3. For example, the component 2 is made of a plastic, such as a thermoplastic, with a predetermined plastic deformability.

[0028] Component 2 has two sections A1 and A2, which are connected to each other via web-shaped projections 2.1. These web-shaped projections 2.1 represent predetermined breaking points S in the form of material weakenings between the two sections A1 and A2 of component 2. According to the Fig. 1, Fig. 2, Fig. 3 to Fig.In the embodiment shown in Figure 4, component 2 has a substantially circular shape, with a projecting area B formed on the outside of an outer section A1. In particular, component 2, i.e., the outer section A1, is firmly connected to the leg 4.1 of the retaining element 4 via this projecting area B. An inner section A2 of component 2 is firmly connected to the end 3.1 of the bolt 3.

[0029] If a vehicle collision is detected and the seatbelt tensioner is activated, a torque acts on bolt 3 due to the frictional forces between the webbing and the bolt. If this torque exceeds a predetermined value, according to which the predetermined breaking points S are designed, these break due to shear forces, separating the two sections A1 and A2 of component 2. Bolt 3 is then no longer fixed and can rotate, thus reducing the frictional forces between the redirected webbing and bolt 3.

[0030] Section A1 with the projecting area B remains firmly connected to leg 4.1 of the retaining element 4 after the predetermined breaking points S have been broken, whereas the inner section A2 and the bolt 3 are freely movable, in particular freely rotatable. A fixed bearing between the retaining element 4 and the bolt 3 is transformed into a floating bearing by breaking the connection between the two sections A1 and A2 of component 2.

[0031] By means of such a deflection element 1, the generation of disturbing noises caused by the fixed mounting of the bolt 3 on the retaining element 4, particularly during vehicle operation, can be largely eliminated. Furthermore, when the belt tensioning mechanism is activated, the frictional forces acting between the belt and the bolt 3 of the deflection element 1 can be reduced by creating a loose bearing with respect to the bolt 3. Thus, it is possible to largely meet the requirements for force limitation that can be dimensioned by the torsion of the torsion bar. Reference symbol list 1 deflection element 2 components 2.1 Shaping 3 bolts 3.1 End 4 retaining elements 4.1 Thigh A1, A2 section Area B S predetermined breaking point

Claims

[1] Seat belt device for a vehicle comprising a webbing, a belt retractor, a deflection element (1) for deflecting the webbing and an activatable belt tensioner with a force limiting unit for force-limited tightening of the applied webbing when an occupant of the vehicle who has fastened the belt moves forward, wherein a bolt (3) of the deflection element (1), over which the webbing is deflected and which is normally mounted in a rotationally and positionally fixed manner, is rotatably mounted when the belt tensioner is activated and when a torque acting on the bolt (3) exceeds a predetermined value, characterized by, that the bolt (3) is coupled to at least one component (2) which is mounted in a rotationally fixed manner during normal operation by means of force-locking and / or form-locking, and that the component (2) has at least one predetermined breaking point (S) which breaks when the specified value with respect to the torque is exceeded and releases a rotational movement of the bolt (3) in the broken state, and that the component (2) has a rotationally fixed section (A1) and a section (A2) which rotates with the bolt (3) after the at least one predetermined breaking point (S) has broken. [2] Safety belt device according to claim 1, characterized by , that the component (2) is coupled to one end (3.1) of the bolt (3) by force and / or form locking. [3] Safety belt device according to claim 2, characterized by , that at least one predetermined breaking point (S) is formed as a material weakening between the rotationally fixed section (A1) and the rotating section (A2). [4] Safety belt device according to one of claims 2 or 3, characterized by , that the component (2) is made of at least one plastic with a given plastic deformability. [5] Vehicle with a safety belt device according to one of the preceding claims.

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