Safety belt device for a vehicle and vehicle

Abstract

The invention relates to a safety belt device for a vehicle, comprising a belt webbing, a belt retractor, a deflection element (1) for deflecting the belt webbing, and an activatable belt tensioner with a force-limiting unit for force-limited tightening of the fastened belt webbing when a vehicle occupant who has fastened the belt webbing is displaced forward. According to the invention, a bolt (3) of the deflection element (1), which bolt is mounted in a rotationally and positionally fixed manner during normal operation and via which the belt webbing is deflected, is rotatably mounted upon activation of the belt tensioner and when a torque acting on the bolt (3) exceeds a predetermined value. Furthermore, the invention relates to a vehicle having such a safety belt device.

Description

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

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

[0003] The invention is based on the object of providing a novel safety belt device for a vehicle and a vehicle with such a safety belt device.

[0004] The object is achieved according to the invention by a safety belt device having the features specified in claim 1 and by a vehicle having the features specified in claim 8.

[0005] A safety belt device for a vehicle comprises a belt webbing, a belt retractor, a deflection element for deflecting the belt webbing, and an activatable belt pretensioner with a force-limiting unit for force-limited tightening of the fastened belt webbing when a vehicle occupant who has fastened the belt webbing is displaced forward. According to the invention, a pin of the deflection element, which is mounted in a rotationally and positionally fixed manner during normal operation and via which the belt webbing is deflected, is rotatably mounted upon activation of the belt pretensioner and when a torque acting on the pin exceeds a predetermined value.

[0006] Normal operation is understood to mean, in particular, driving operation in which the vehicle is not exposed to collision-related acceleration.

[0007] By means of a deflection element designed in this way, it is possible to reduce belt friction forces on the pin of the deflection element when the occupant is displaced forward, in particular when the specified value is exceeded. Since the pin is mounted in a rotationally and positionally fixed manner during normal operation of the seat belt device, in particular by means of a fixed bearing, unwanted noise development, such as rattling, when the vehicle is in motion can be largely eliminated. This means that no disturbing noises occur when the vehicle is in motion due to a so-called loose bearing. The fixed bearing of the pin is specifically released to form a so-called loose bearing, so that the pin can rotate, whereby the frictional forces acting between the belt webbing and the deflection element, in particular those between the belt webbing and the pin, can be reduced.This makes it possible to design a torsion bar of appropriate dimensions to limit the belt force when the belt is tightened.

[0008] In one embodiment, the bolt is force-locked and / or form-locked coupled to at least one component that is mounted in a rotationally fixed manner during normal operation, and the component has at least one predetermined breaking point. This at least one component coupled to the bolt serves to convert the fixing element into a loose bearing so that the bolt can rotate, whereby the frictional forces between the belt webbing and the bolt, i.e. the belt deflection element, can be reduced. The at least one predetermined breaking point breaks when the predetermined value is exceeded in terms of torque and releases a rotational movement of the bolt so that the frictional forces between the belt webbing and the deflection element are reduced during belt tensioning with force limitation. The bolt can rotate in accordance with a tensile force acting on the belt webbing so that the belt webbing essentially does not slide along the bolt, which creates the frictional forces.

[0009] In one possible embodiment, the component has a section mounted in a rotationally fixed manner and a section that rotates with the bolt after the at least one predetermined breaking point has been broken. After the at least one predetermined breaking point has been broken, the component has the two sections in the form of two parts, allowing the bolt of the deflection element to rotate, forming a floating bearing. The rotational movement of the bolt now possible can reduce the frictional forces between the webbing and the bolt.

[0010] In a further embodiment, the at least one predetermined breaking point is formed as a weakened material section between the rotationally fixed section and the co-rotating section. This weakened material section 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 caused by tensile forces acting on it. This allows the bolt to be rotatably mounted and reduces the frictional forces between the webbing and the bolt.

[0011] Even if the material weakening, i.e. the predetermined breaking point, fails prematurely, this does not result in any functional restriction of the deflection element, the belt tensioning and the force limitation during belt tensioning.

[0012] In another possible embodiment, the component is formed from at least one plastic with a predetermined plastic deformability. The plastic deformability is predetermined, particularly with respect to the predetermined breaking point, so that the sections of the component can position themselves relative to one another until the predetermined breaking point yields and breaks, allowing the rotational movement of the bolt to reduce the frictional forces between the belt webbing and the bolt. During normal operation, however, the bolt is fixedly mounted to the component, which largely prevents noise from the deflection element, especially when the vehicle is in motion.

[0013] Furthermore, the invention relates to a vehicle with a safety belt device, which is designed according to the invention such that the pin of the deflection element, which is mounted in a rotationally and positionally fixed manner during normal operation and via which the belt webbing is deflected, is rotatably mounted upon activation of the belt tensioner and when a torque acting on the pin exceeds a predetermined value. The pin is then rotatably mounted, so that the frictional forces between the pin and the belt webbing can be reduced, particularly upon activation of the belt tensioner.

[0014] Embodiments of the invention are explained in more detail below with reference to drawings.

[0015] Showing: Fig. 1 schematically shows a perspective view of a deflection element for a belt strap of a safety belt device of a vehicle, Fig. 2 schematically shows another perspective view of the deflection element, Fig. 3 schematically shows a side view of the deflection element and Fig. 4 schematically shows a component for reducing frictional forces.

[0016] Corresponding parts are provided with the same reference numerals in all figures.

[0017] Fig. 1 shows a perspective view of a deflection element 1 for deflecting a belt strap (not shown in detail) of a safety belt device of a vehicle.

[0018] Fig. 2 shows a further perspective view of the deflection element 1, whereas in Fig. 3 a side view of the deflection element 1 and in Fig. 4 a component 2 for reducing frictional forces between the belt strap and a bolt 3 of the deflection element 1 is shown.

[0019] The safety belt device, which comprises the deflection element 1 and the belt 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 belt webbing when an occupant of the vehicle is displaced forward.

[0020] For example, it is a pyrotechnically triggered and / or electric motor-operated belt tensioner.

[0021] Such a belt tensioner is designed to tighten the belt webbing, particularly in the event of a vehicle collision, so that it sits relatively close to the occupant's body, allowing the occupant to participate in the overall deceleration of the vehicle relatively early. A force limiting unit, also known as a belt force limiter, is provided to limit the maximum force exerted on the occupant during a collision by the tensioning of the belt webbing.

[0022] The force limiting unit is designed as a torsion bar, which rotates counter to the winding direction of the belt retractor to limit the tensioning force acting on the belt webbing. This reduces the restraining force exerted on the occupant by the belt webbing, particularly to biomechanically tolerable limits. This force limiting mechanism can, for example, largely prevent the occupant's ribs from breaking.

[0023] Typically, the deflection element 1 for deflecting the belt webbing, for example within an integral belt seat or concealed by a panel on a B-pillar of the vehicle, comprises a bolt 3 along which the belt webbing slides and is deflected, particularly when unwinding from a belt retractor or when winding onto the belt retractor. The bolt 3 is arranged in a rotationally and positionally fixed manner on a holding element 4 of the deflection element 1. If the bolt 3 is not rotationally fixed to the holding element 4, there is a risk of annoying noise development, in particular rattling, during normal operation of the seat belt device, particularly when the vehicle is moving. Typically, the bolt 3 is firmly mounted on the holding element 4. Thus, no undesirable noise is generated; however, the fixed mounting of the bolt 3 means that frictional forces between the bolt 3 and the belt webbing are comparatively high, particularly when the belt tensioning is activated.These frictional forces acting on the deflection of the belt strap significantly determine the dimensioning of the torsion bar as a force limiting unit of the safety belt device.

[0024] In order to form the deflection element 1 so that the frictional forces between the bolt 3 and the belt webbing are reduced during belt tensioning, which is triggered, for example, pyrotechnically and / or electrically, the deflection element 1 is designed as described below.

[0025] The bolt 3 is fixedly arranged on the holding 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 holding element 4 by means of the component 2, with the component 2 being arranged on the outside of a leg 4.1 of the holding element 4 and being positively and non-positively connected to the end 3.1 of the bolt 3. For example, the component 2 is formed from a plastic, for example a thermoplastic, with a predetermined plastic deformability.

[0026] The component 2 has two sections A1, A2, which are connected to each other via web-shaped formations 2.1. These web-shaped formations 2.1 represent predetermined breaking points S in the form of material weakenings between the two sections A1, A2 of the component 2. According to the Fig.In the embodiment shown in Figures 1 to 4, the component 2 has a substantially circular shape, with a projecting region B formed on the outside of an outer section A1. In particular, the component 2, i.e., the outer section A1, is firmly connected to the leg 4.1 of the retaining element 4 via this projecting region B. An inner section A2 of the component 2 is firmly connected to the end 3.1 of the bolt 3.

[0027] If a vehicle collision is detected and the belt tensioner is activated, a torque is exerted on the belt due to the frictional forces between the belt webbing and the bolt 3. If this torque exceeds a predetermined value corresponding to the design of the predetermined breaking points S, these break due to the shearing forces acting on them, so that the two sections A1, A2 of component 2 are separated from each other. Thus, the bolt 3 is no longer fixed and can rotate, reducing the frictional forces between the belt webbing resting on the bolt 3 and deflected by the bolt 3 and the bolt 3.

[0028] After the predetermined breaking points S have been broken, the section A1 with the projecting area B remains firmly connected to the leg 4.1 of the retaining element 4, whereas the inner section A2 and the bolt 3 are freely movable, in particular freely rotatable. A loose bearing is formed from a fixed bearing between the retaining element 4 and the bolt 3 by removing the connection between the two sections A1, A2 of the component 2.

[0029] By means of a deflection element 1 designed in this way, the generation of disturbing noises due to the fixed mounting of the bolt 3 on the retaining element 4, particularly during vehicle operation, can be largely eliminated. However, when the belt tensioning is activated, the formation of the loose bearing with respect to the bolt 3 of the deflection element 1 can reduce the frictional forces acting between the belt webbing and the bolt 3. This makes it possible to largely meet requirements regarding a force limitation dimensioned by the torsion of the torsion bar. List of reference symbols 1 deflection element 2 component 2.1 Formation 3 bolts 3.1 End 4 Holding element 4.1 Legs A1, A2 section B area S predetermined breaking point QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 0 487 760 A1

[0002]

Claims

[1] Safety belt device for a vehicle with a belt strap, a belt retractor, a deflection element (1) for deflecting the belt strap and an activatable belt tensioner with a force limiting unit for force-limited tightening of the fastened belt strap when a passenger of the vehicle who has fastened the belt strap is displaced forward, characterized by that a bolt (3) of the deflection element (1), via which the belt webbing is deflected and which is mounted in a rotationally and positionally fixed manner during normal operation, is rotatably mounted when the belt tensioner is activated and when a torque acting on the bolt (3) exceeds a predetermined value. [2] Safety belt device according to claim 1, characterized bythat the bolt (3) is coupled in a force-locking and / or form-locking manner to at least one component (2) which is mounted in a rotationally fixed manner during normal operation, and the component (2) has at least one predetermined breaking point (S) which breaks when the predetermined value is exceeded in relation to the torque and, in the broken state, releases a rotational movement of the bolt (3). [3] Safety belt device according to claim 2, characterized by that the component (2) is coupled to one end (3.1) of the bolt (3) in a force-locking and / or form-locking manner. [4] Safety belt device according to claim 2 or 3, characterized by that the component (2) has a section (A1) mounted in a rotationally fixed manner and a section (A2) which rotates with the bolt (3) after the at least one predetermined breaking point (S) has broken. [5] Safety belt device according to claim 4, characterized bythat the at least one predetermined breaking point (S) is designed as a material weakening between the rotationally fixed section (A1) and the rotating section (A2). [6] Safety belt device according to one of claims 2 to 5, characterized by that the component (2) is formed from at least one plastic with a predetermined plastic deformability. [7] Vehicle with a safety belt device according to one of the preceding claims.

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