Restraining device for an occupant seat on a vehicle seat of a motor vehicle, vehicle seat comprising a restraining device, and restraining system

Abstract

The invention relates to a restraint device (4) for an occupant sitting on a vehicle seat (1) of a motor vehicle, comprising a seat belt retractor (6), which comprises a frame that can be fastened in a vehicle-fixed manner, and a seat belt shaft, which can be fastened in a vehicle-fixed manner, the invention relates to a seat belt device (1) for a vehicle occupant, comprising a frame (2), a seat belt shaft (3), which is rotatably mounted in the frame, and a seat belt (5), which can be wound on the seat belt shaft at one end and is guided over the shoulder of the occupant in order to restrain the occupant, a rotational angle sensor is provided which detects a rotational movement of the seat belt shaft, and-a position sensor (15) is provided which generates a signal representing a feed angle of the seat belt (5) above the shoulder of the occupant.

Description

Field of the Invention

[0001] The present invention relates to a restraint device for an occupant sitting on a vehicle seat of a motor vehicle having the features of the preamble of claim 1, a vehicle seat having the features of the preamble of claim 3, and a restraint system having the features of the preamble of claim 7. Background Art

[0002] In particular, the three-point seat belt has proven effective as a restraint device for an occupant sitting on a vehicle seat in a motor vehicle. These seat belts have a seat belt as a basic element, one end of which is windable around a seat belt shaft of a seat belt retractor, which is fastened in a vehicle-fixed manner to one side of the vehicle seat, and the other end of which is fastened in a vehicle-fixed manner to the same side of the vehicle seat using an end fitting. In addition, a movable seat belt tongue is provided on the seat belt, which can be locked in a seat belt buckle fastened in a vehicle-fixed manner to the other side of the vehicle seat, so as to divide the seat belt into a diagonal seat belt portion passing through the occupant's chest and a waist seat belt portion passing through the occupant's pelvis. The seat belt shaft around which the seat belt can be wound is rotatably mounted in a frame of the seat belt retractor and has a blocking device, which is activated in accordance with an acceleration of pulling out of the seat belt exceeding a predetermined value and / or a vehicle deceleration exceeding a predetermined value, and blocks further rotation of the seat belt shaft in the pulling-out direction of the seat belt in order to restrain the occupant.

[0003] In addition, modern restraint devices may additionally be provided with reversible and / or irreversible seat belt pretensioners and / or controllable or uncontrollable force limiting devices, by means of which the restraint characteristics of the restraint device can be further optimized, particularly with regard to the smallest possible occupant loading.

[0004] One problem with such restraint devices is that restraint of the occupant requires the occupant to actually be wearing the seat belt. Since the restraint device generally causes at least a slight restriction of the occupant's freedom of movement during use, there are occupants, such as professional motor vehicle drivers, who in principle refuse to put on the restraint device. In addition, there remains the basic problem that occupants sometimes forget to put on the restraint device.

[0005] To remind the occupant to wear a restraint device, seat belt warning devices have proven to be effective. If the occupant has not put on the restraint device, they emit an audible warning tone. This acoustic warning tone can become louder over time, so that even reluctant occupants will eventually put on the restraint device to turn off the warning tone. In addition to occupant detection, the seat belt warning device also includes a seat belt buckle sensor that detects the insertion state of the seat belt tongue.

[0006] It has been found that particularly reluctant occupants simulate a false fastening state by inserting a separate seat belt tongue into a seat belt buckle that is not connected to the seat belt. There are also occupants who pull out the seat belt, lock the seat belt tongue in the seat belt buckle, and then sit on the seat belt.

[0007] In addition, inflatable airbags have proven to be effective in restraining occupants. These airbags are fastened to the vehicle structure and inflated in the event of an accident to protect the occupants from the impact of the interior vehicle structure. To optimize the restraint function of the airbags, these airbags can be inflated to a specific occupant-specific geometry by means of a tensioning belt, a tear seam, or a controllable inflator. For this purpose, it is necessary to detect the occupant type, and a rough classification of the occupant type according to dimensions and / or the size of the abdominal circumference is sufficient. Such occupant detection and classification can also be used to control a controllable force limiting device or a controllable tensioning device. SUMMARY OF THE INVENTION

[0008] In this context, the object of the present invention is to provide a restraint device, a vehicle seat, and a restraint system that allow improved detection of improper use of the restraint device and occupant detection.

[0009] To achieve this object, a restraint device having the features according to claim 1, a vehicle seat having the features according to claim 3, and a restraint system having the features according to claim 7 are proposed. Further preferred developments of the present invention can be obtained from the dependent claims, the drawings, and the related description.

[0010] According to the basic idea of the present invention, it is proposed to provide a rotational angle sensor that detects the rotational movement of the seat belt axis, and a position sensor that generates a signal representing the supply angle of the seat belt above the occupant's shoulder.

[0011] The proposed restraint device can easily detect an incorrect fastening state of the seat belt or an unfastened seat belt by first detecting the rotational movement of the seat belt shaft via a rotational angle sensor and thus detecting the extension movement of the seat belt itself. If the seat belt has not been pulled out and fastened, this can be easily detected by the signal from the rotational angle sensor, eliminating the need for the previously required seat belt buckle sensor. Then, the supply angle of the seat belt relative to the occupant is detected by means of a position sensor. If this supply angle lies outside the defined range of the supply angle for the correct seat belt fastening state, it can be directly concluded that the seat belt is in an incorrect fastening state. This can be used, for example, to detect an incorrect fastening state when the occupant has already sat on the seat belt and the seat belt extends between the backrest and the occupant's back. In addition, the number of revolutions of the seat belt shaft and the rotational angle of the seat belt shaft detected by the rotational angle sensor can be used to draw conclusions about the derived length of the seat belt and thus about the body proportions of the occupant (such as height, chest circumference, and chest width).

[0012] Furthermore, it is proposed that a deflection device be provided on which the seat belt is deflected towards the occupant, and the position sensor detects the position and orientation of the seat belt after it has been deflected towards the occupant. The seat belt is deflected towards the occupant by the deflection device so that the seat belt retractor itself can be arranged in a positioning that is convenient for installation. Then, the seat belt extends from the seat belt retractor to the deflection device (regardless of whether the seat belt is fastened and the occupant is sitting on the vehicle seat), and is deflected towards the occupant only at the deflection device, or, if the seat belt is not in the fastened state, to a parked position. The proposed arrangement of the position sensor directly detects the arrangement and orientation of the seat belt in the supply to the occupant, so that a direct conclusion can be drawn as to whether the occupant has fastened his or her seat belt.

[0013] Furthermore, for this purpose, a vehicle seat having a restraint device according to claim 1 or claim 2 is proposed, in which the seat belt retractor is fastened in the backrest of the vehicle seat. Due to the arrangement of the seat belt retractor in the backrest, the vehicle seat having the seat belt retractor provides restraint for the occupant sitting on the vehicle seat via the seat belt pulled by the seat belt retractor, regardless of the position, arrangement, and orientation of the vehicle seat in the vehicle. This is particularly advantageous in autonomous vehicles, where the vehicle seat can be adjusted within a relatively large adjustment range and, in particular, can be rotated.

[0014] In a vehicle seat having a restraint device according to claim 2 according to claim 3, the deflection device is preferably arranged in the upper edge portion of the backrest such that the seat belt extends over the occupant's shoulder from above when being supplied to the occupant.

[0015] Furthermore, it is proposed that a position sensor in the vehicle seat detects the distance between the seat belt and the backrest. The distance of the seat belt to the backrest is a parameter that is very easy to detect, and taking into account the position of the position sensor, this distance allows a very simple determination of the path along which the seat belt is supplied to the occupant.

[0016] Furthermore, it is proposed that the position sensor detects the angle at which the seat belt extends orthogonally to the backrest with respect to the pivot axis. This can be achieved, for example, by detecting the overlap of the position sensor with the seat belt. This makes it possible to detect the orientation of the seat belt towards the seat surface or away from the vehicle seat.

[0017] Furthermore, to achieve this purpose, a restraint system having a restraint device according to claim 1 or claim 2 or a vehicle seat according to any one of claims 3 to 6 is proposed, wherein an evaluation device is provided in which a control signal is generated based on the signals of a rotational angle sensor and a position sensor. In the evaluation device, the signals from the rotational angle sensor and the position sensor are combined, which in turn allows for a more accurate conclusion to be drawn regarding the fastening state and fastening geometry of the seat belt.

[0018] Furthermore, it is proposed that a controllable airbag device and / or a controllable force limiting device and / or a controllable tensioning device is provided in the restraint system, and the airbag device and / or the force limiting device and / or the tensioning device is controlled based on the control signal. The advantage of the proposed further development is that by the proposed control of the airbag device, the force limiting device and / or the tensioning device, the restraint of the occupant can be achieved on an occupant-specific basis and in particular according to the seat belt fastening state and the seat belt fastening geometry.

[0019] Furthermore, it is proposed that an acoustic and / or optical warning device is provided and the optical and / or acoustic warning device is activated based on the control signal. The acoustic and / or optical warning device can warn the occupant of a seat belt malfunction and / or non-fastening. Description of the Drawings

[0020] The present invention will be explained below using preferred embodiments with reference to the drawings. In the drawings:

[0021] Figure 1 is a perspective view and an enlarged cross-section of a vehicle seat having a restraint device according to the present invention according to the present invention, and

[0022] Figure 2Yes Figure 1 front view of a vehicle seat and restraint device, and

[0023] Figure 3 is a vehicle seat and restraint device having a steering wheel and an airbag device Figure 1 side view. DETAILED DESCRIPTION

[0024] Figure 1 and Figure 2 show a vehicle seat 1 according to the invention having a seat surface 3, a backrest 2 and a headrest 9. Furthermore, a restraint device 4 is provided on the vehicle seat 1, which restraint device has a seat belt retractor 6, a seat belt 5, a deflection device 18, a seat belt buckle 7 fastened to the vehicle seat 1, a seat belt tongue (not shown) displaceably guided on the seat belt 5 and an end fitting (likewise not shown) fastened to the vehicle seat 1. If it is not possible to fasten to the vehicle seat or the vehicle seat can only be displaced or moved to such an extent that an occupant sitting thereon is safely restrained in all possible positions of the vehicle seat 1 and in the event of an accident, the seat belt buckle 7, the end fitting and the seat belt retractor 6 can also be fastened to the external vehicle structure.

[0025] The seat belt retractor 6 includes a seat belt shaft (not shown), which seat belt shaft is rotatably mounted in a frame (also not shown) fastened in a vehicle-fixed manner. The seat belt 5 is held at its upper end on the seat belt shaft, which seat belt shaft is spring-loaded relative to the frame in the winding direction, such that the seat belt 5 automatically winds up at this end and is pulled out against the spring force when pulled out. The seat belt retractor 6 and the end fitting (not shown) are fastened to the same side of the vehicle seat 1, while the seat belt buckle 7 is fastened to the opposite side of the vehicle seat 1. To fasten the seat belt 5, the occupant pulls out the seat belt 5 and locks the seat belt tongue in the seat belt buckle, thereby creating a proven three-point geometry of the seat belt 5, in which the diagonal seat belt part 10 passes across the occupant's chest, while the waist seat belt part 11 passes across the pelvis.

[0026] Furthermore, the restraint device 4 includes a position sensor 15 arranged in the upper edge part 8 of the backrest 2 below the deflection device 18 and a rotational angle sensor 16 assigned to the seat belt shaft of the seat belt retractor 6. The restraint device 4 in the vehicle seat 1 is part of a restraint system which can be in Figure 3as can be seen, and the restraint system further includes an evaluation device 17, a controllable airbag device 14 arranged in the steering wheel 19, a controllable force limiting device 12 for the seat belt shaft of the seat belt retractor 6, and a controllable tensioning device 13 also assigned to the seat belt shaft.

[0027] However, both the controllable force limiting device 12 and the controllable tensioning device 13 as well as the controllable airbag device 14 can also be arranged differently. Thus, the controllable force limiting device 12 and the controllable tensioning device can also be assigned to the seat belt buckle 7, the end fitting or the deflection device 18. Additionally, the controllable airbag device 14 can also be arranged in the instrument panel, in the roof structure, in the side structure or in the footwell of the vehicle.

[0028] The rotational angle sensor 16 is arranged in such a way that it generates a signal related to the rotational movement of the seat belt shaft, and based on this signal, the pull-out length of the seat belt 5 from the seat belt shaft can also be directly determined by counting the number of revolutions and the rotational angle of the seat belt shaft. The position sensor 15 is arranged in the backrest 2 below the deflection device 18, and its sensor field is oriented in such a way that when the seat belt 5 pivots about a pivot axis 21 oriented orthogonally to the backrest 2, due to the change in overlap, the position sensor generates a changing signal, which allows conclusions to be drawn about the orientation of the seat belt 5. The signal change in particular allows the detection of the orientation of the seat belt 5 in the directions towards the outside O, towards the inside I, upwards U and downwards D, as can be seen in the Figure 1 magnified illustration. Additionally, the position sensor 15 is additionally designed such that when Figure 3 the distance A of the seat belt 5 shown to the position sensor 15 changes, the position sensor generates a changing signal.

[0029] The advantage of the restraint device 4 according to the invention is that an incorrectly fastened state or even an unfastened seat belt 5 can be detected very easily and reliably in the following way: First, the pulling-out process of the seat belt 5 is detected via the signal of the rotational angle sensor 16, and then the position and orientation of the seat belt 5 are detected via the position sensor 15. Thus, a seat belt buckle sensor is no longer required, and it is not possible to bypass this seat belt buckle sensor by simply inserting a seat belt tongue without a seat belt.

[0030] In this case, an incorrectly fastened state of the seat belt 5 can be detected in particular by the position sensor 15 detecting the orientation and arrangement of the seat belt 5, which are outside the range of the orientation and arrangement of the seat belt 5 defined for the correct fastening state.

[0031] Furthermore, the restraint device 4 according to the invention can be used to perform a very simple occupant classification by means of which an occupant-specific control of the restraint of the occupant can be carried out in the restraint system according to the invention, which has a controllable airbag device 14, a controllable force-limiting device 12 and / or a controllable tensioning device.

[0032] For example, a tall occupant can be identified by detecting the extension length of the seat belt 5 (which is greater than a defined value), and the position sensor 15 detects a greater distance A (i.e., a greater angle) of the seat belt 5 compared to a predefined distance A or angle relative to the backrest 2. Furthermore, conversely, if the extension length and distance A of the seat belt 5 are less than a predefined value, a short occupant can be detected.

[0033] Likewise, a fat occupant with a large chest circumference can be distinguished from a slender occupant with a small chest circumference.

[0034] The position sensor 15 is arranged in the backrest 2 below the deflection device 18 and its sensor field is directed towards the upper side of the seat belt 5 facing the backrest 2. This detects the orientation of the seat belt 5 in the region of the diagonal seat belt section 10 extending from the deflection device 18, which orientation is decisive for restraining the upper body of the occupant and bears against the upper body of the occupant. Since the arrangement and orientation of the diagonal seat belt section 10 particularly represent the seat belt fastening state and the body proportions of the occupant, a particularly accurate and reliable detection of the seat belt fastening state and body proportions is possible. These body proportions are in turn decisive for the weight of the occupant and its geometry, which weight and geometry of the occupant are in turn decisive for the restraint of the occupant, so that the restraint of the occupant can be individually improved by appropriate occupant-specific control of the airbag device 14, the force-limiting device 12 and the tensioning device 13. In this case, the occupant detection and the detection of the seat belt fastening state can be carried out by using only two sensors, namely the rotation angle sensor 16 and the position sensor 15, and the small additional costs are compensated by omitting the previously provided seat belt buckle sensor.

[0035] Furthermore, the restraint system additionally includes a controllable acoustic and / or optical warning device 20, which is activated by means of a signal generated by the evaluation unit 17, which signal is in turn generated based on the signals of the rotation angle sensor 16 and / or the position sensor 15, and attracts the attention of the occupant to the incorrectly fastened or unfastened seat belt 5.

Claims

1. A restraint device (4) for an occupant sitting on a vehicle seat (1) of a motor vehicle, the restraint device comprising - a seat belt retractor (6), the seat belt retractor comprising - a frame that can be fastened in a vehicle-fixed manner, and - a seat belt shaft that is rotatably mounted in the frame, and - a seat belt (5) that can be wound at one end onto the seat belt shaft and is guided over the occupant's shoulder to restrain the occupant, characterized in that - a rotational angle sensor (16) is provided, which detects the rotational movement of the seat belt shaft, and - a position sensor (15) is provided, which generates a signal representing the supply angle of the seat belt (5) above the occupant's shoulder.

2. The restraint device (4) according to claim 1, characterized in that - a deflection device (18) is provided, at which the seat belt (5) is deflected towards the occupant, and - the position sensor (15) detects the position and orientation of the seat belt (5) after deflection towards the occupant.

3. A vehicle seat (1), the vehicle seat comprising the restraint device (4) according to claim 1 or claim 2, characterized in that - the seat belt retractor (6) is fastened in the backrest (2) of the vehicle seat (1).

4. The vehicle seat (1) according to claim 3, the vehicle seat having the restraint device (4) according to claim 2, characterized in that - the deflection device (18) is arranged in the upper edge portion (8) of the backrest (2).

5. The vehicle seat (1) according to claim 3 or claim 4, characterized in that - the position sensor (15) detects the distance (A) of the seat belt (5) from the backrest (2).

6. The vehicle seat (1) according to any one of claims 3 to 5, characterized in that - the position sensor (15) detects the angle (W) of the seat belt (5) relative to a pivot axis extending orthogonally to the backrest (2).

7. A restraint system having the restraint device (4) according to claim 1 or claim 2, or having a vehicle seat according to any one of claims 3 to 6, characterized in that - an evaluation device (17) is provided, in which a control signal is generated based on the signals of the rotational angle sensor (16) and the position sensor (15).

8. The restraint system according to claim 7, characterized in that - a controllable airbag device (14) and / or a controllable force limiting device (12) and / or a controllable tensioning device (13) are provided, and - the airbag device (14) and / or the force limiting device (12) and / or the tensioning device (13) are controlled based on the control signal.

9. The restraint system according to claim 7 or claim 8, characterized in that - an acoustic and / or optical alarm device (20) is provided, and - the optical and / or acoustic alarm device (20) is activated according to the control signal.

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