Restraint device for an occupant seated on a vehicle seat of a motor vehicle, vehicle seat with a restraint device, and restraint system

Abstract

To improve detection of improper use of restraint devices and occupant detection. [Solution] The present invention relates to a restraint device (4) for an occupant seated in a vehicle seat (1) of a motor vehicle, comprising: - a seat belt retractor (6) - the seat belt retractor (6) having a frame that can be fastened so as to be fixed to the vehicle, and - a seat belt shaft rotatably mounted within the frame; - a seat belt (5) that can be wound onto the seat belt shaft at one end and guided over the occupant's shoulder to restrain the occupant, - a rotation angle sensor (16) is provided that detects rotational movement of the seat belt shaft, and - a position sensor (15) is provided that generates a signal representative of the feed angle of the seat belt (5) over the occupant's shoulder.

Description

[Technical Field]

[0001] The present invention relates to a restraint device for an occupant seated 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.

[0002] Three-point seat belts have proven particularly effective as restraint devices for occupants seated on vehicle seats in motor vehicles. These seat belts have, as a basic element, a seat belt, one end of which can be retracted onto a seat belt shaft of a seat belt retractor fastened to one side of the vehicle seat and fastened to the vehicle using an end attachment to the same side of the vehicle seat. Furthermore, the seat belt is provided with a movable seat belt tongue, which can be locked into a seat belt buckle fastened to the other side of the vehicle seat to separate the seat belt into a diagonal seat belt portion across the occupant's chest and a lap seat belt portion across the occupant's pelvis. The seat belt shaft that can retract the seat belt has a rotatable mounting device on the frame of the seat belt retractor and a blocking device that is actuated in response to exceeding a predetermined seat belt withdrawal acceleration and / or exceeding a predetermined vehicle deceleration, preventing further rotation of the seat belt shaft in the seat belt withdrawal direction to restrain the occupant.

[0003] Furthermore, modern restraint systems may further comprise reversible and / or irreversible seat belt tensioning devices and / or controllable or uncontrollable force limiting devices, whereby the restraint characteristics of the restraint system can be further optimized, particularly with regard to the lowest possible occupant loads.

[0004] One problem with such restraint systems is that restraining an occupant requires that the occupant actually wear a seat belt. Because restraint systems, when in use, typically restrict the occupant's freedom of movement at least slightly, some occupants, such as professional motorists, generally refuse to wear restraint systems. Furthermore, there remains the fundamental problem that occupants may forget to wear restraint systems.

[0005] Seat belt warning devices have proven effective in reminding occupants to fasten their restraints. These emit an audible warning if the occupant does not fasten the restraint. This audible warning can become louder over time, so that even unwilling occupants eventually fasten their restraints to turn off the warning. In addition to occupant detection, seat belt warning devices include a seat belt buckle sensor that detects the insertion status of the seat belt tongue.

[0006] Particularly unwilling occupants have been known to simulate a false fastening condition by inserting a separate seat belt tongue into the seat belt buckle that is not connected to the seat belt, or by pulling out the seat belt to lock the seat belt tongue into the seat belt buckle, and then sitting down on the seat belt.

[0007] Additionally, inflatable airbags have proven effective in restraining occupants. These airbags are fastened to the vehicle structure and inflate during an accident to protect the occupant from impact with the interior vehicle structure. To optimize the restraint function of the airbag, the airbag can be inflated to a specific occupant-specific shape by tensioning straps, tear seams, or a controllable inflator. This requires detecting the occupant type, and roughly classifying the occupant type according to size and / or waist circumference is sufficient. Such occupant detection and classification can also be used to control a controllable force-limiting device or a controllable tensioning device.

[0008] Against this background, it is an object of the present invention to provide a restraint device, a vehicle seat, and a restraint system that allows for improved detection of improper use of the restraint device and improved occupant detection.

[0009] To this end, a restraint device is proposed having the features of claim 1, a vehicle seat having the features of claim 3, and a restraint system having the features of claim 7. Further advantageous developments of the invention can be taken from the dependent claims, the drawings and the associated description.

[0010] According to the basic idea of ​​the present invention, it is proposed that a rotation angle sensor is provided which detects the rotational movement of the seat belt shaft, and a position sensor is provided which generates a signal representative of the feed angle of the seat belt on the shoulder of the occupant.

[0011] The proposed restraint device first detects the rotational movement of the seat belt shaft, and therefore the extension movement of the seat belt, via a rotation angle sensor, allowing for easy detection of an incorrectly fastened or unfastened seat belt. If the seat belt is not withdrawn and fastened, this can be easily detected by the signal from the rotation angle sensor, thus eliminating the need for a seat belt buckle sensor, as previously required. The seat belt feed angle relative to the occupant is detected by a position sensor. If the feed angle is outside a predetermined range of feed angles for a properly fastened seat belt, a direct conclusion can be drawn that the seat belt is incorrectly fastened. This can be used, for example, to detect an incorrect fastening when an occupant sits in the seat belt and the seat belt extends between the seat back and the occupant's back. Furthermore, the number of rotations of the seat belt shaft and the rotation angle of the seat belt shaft detected by the rotation angle sensor can be used to draw conclusions about the extension length of the seat belt and therefore about the occupant's physical proportions, such as height, chest circumference, and chest width.

[0012] Furthermore, it is proposed that a deflection device is provided by which the seat belt is deflected toward the occupant, and that a position sensor detects the position and orientation of the seat belt after deflection toward the occupant. The seat belt toward the occupant is deflected by the deflection device, so that the seat belt retractor itself can be located in a convenient location for installation. The seat belt extends from the seat belt retractor to the deflection device regardless of whether the seat belt is fastened and whether the occupant is seated on the vehicle seat, and is only deflected toward the occupant at the deflection device or to the parking position if the seat belt is not fastened. The proposed location of the position sensor directly detects the position and orientation of the seat belt sent to the occupant, so that a direct conclusion can be drawn as to whether the occupant has fastened the seat belt.

[0013] Furthermore, to achieve this object, a vehicle seat is proposed having a restraint device according to claim 1 or 2, in which a seat belt retractor is fastened to the backrest of the vehicle seat. By locating the seat belt retractor in the backrest, the vehicle seat with the seat belt retractor provides restraint of the occupant seated on the vehicle seat via the seat belt tensioned by the seat belt retractor, independent of the position, arrangement and orientation of the vehicle seat within the vehicle. This is particularly advantageous in autonomous vehicles, where the vehicle seat may be adjusted over a fairly large adjustment range, and in particular may be rotated.

[0014] In a vehicle seat as claimed in claim 3 having a restraint device as claimed in claim 2, the deflection device is preferably arranged in the upper edge portion of the backrest so that the seat belt extends from above the occupant's shoulders when being routed to the occupant.

[0015] It is further proposed that a position sensor in the vehicle seat detects the distance of the seat belt from the seat back, which is a very easy parameter to detect, and by taking into account the position of the position sensor, the path of the seat belt routed to the occupant can be very easily determined.

[0016] It is further proposed that the position sensor detects the angle of the seat belt relative to a pivot axis extending perpendicular to the seat back. 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 direction of the seat belt towards or away from the seat cushion of the vehicle seat.

[0017] Furthermore, to achieve this object, a restraint system is proposed having a restraint device as defined in claim 1 or 2, or a vehicle seat as defined in any one of claims 3 to 6, and an evaluation device is provided in which a control signal is generated from signals from the rotation angle sensor and the position sensor. In the evaluation device, the signals from the rotation angle sensor and the position sensor are combined, which makes it possible to draw more accurate conclusions about the fastening state and fastening shape of the seat belt.

[0018] It is further 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, the airbag device and / or the force limiting device and / or the tensioning device being controlled in response to a control signal. The proposed further development is advantageous in that restraint of the occupant can be achieved by the proposed control of the airbag device, the force limiting device and / or the tensioning device on an occupant-specific basis, in particular in response to the seat belt fastening state and the seat belt fastening geometry.

[0019] It is further proposed that an acoustic and / or optical warning device is provided, the optical and / or acoustic warning device being activated depending on the control signal, the acoustic and / or optical warning device being able to warn the occupant of a seat belt malfunction and / or non-fastening. [Brief explanation of the drawings]

[0020] The present invention will be described below using preferred embodiments with reference to the accompanying drawings, in which: [Figure 1]1 is a perspective view and an enlarged cross-sectional view of a vehicle seat according to the invention having a restraint device according to the invention; [Figure 2] FIG. 2 is a front view of the vehicle seat and restraint device of FIG. 1. [Figure 3] 2 is a side view of the vehicle seat and restraint system of FIG. 1 with a steering wheel and airbag system. DETAILED DESCRIPTION OF THE INVENTION

[0021] 1 and 2 show a vehicle seat 1 according to the invention, which has a seat cushion 3, a backrest 2, and a headrest 9. Furthermore, a restraint device 4 is provided on the vehicle seat 1, which comprises a seat belt retractor 6, a seat belt 5, a deflector 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 attachment (also not shown) fastened to the vehicle seat 1. The seat belt buckle 7, the end attachment, and the seat belt retractor 6 can also be fastened to external vehicle structures if fastening to the vehicle seat is not possible or if the vehicle seat is only displaceable or movable to the extent that an occupant seated on the vehicle seat is safely restrained in all possible positions and accident scenarios of the vehicle seat 1.

[0022] The seat belt retractor 6 includes a seat belt shaft (not shown) rotatably mounted on a frame (not shown) fixedly fastened to the vehicle. The seat belt 5 is held at its upper end on the seat belt shaft, which is spring-biased in the winding direction relative to the frame, so that the seat belt 5 automatically winds at this end and is unwound against the spring force when unwound. The seat belt retractor 6 and the end attachment (not shown) are fastened to the same side of the vehicle seat 1, and the seat belt buckle 7 is fastened to the opposite side of the vehicle seat 1. To fasten the seat belt 5, the occupant unwinds the seat belt 5 and locks the seat belt tongue into the seat belt buckle, resulting in the proven three-point shape of the seat belt 5, with the diagonal seat belt portion 10 across the occupant's chest and the lap seat belt portion 11 across the pelvis.

[0023] Furthermore, the restraint device 4 comprises a position sensor 15 arranged in the upper edge part 8 of the seat back 2 below the deflection device 18, and a rotation 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 visible in Figure 3, which further comprises an evaluation device 17, a controllable airbag device 14 arranged in the steering wheel 19, a controllable force limiting device 12 assigned to the seat belt shaft of the seat belt retractor 6, and a controllable tensioning device 13 also assigned to the seat belt shaft.

[0024] 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 attachment or the deflection device 18. Furthermore, the controllable airbag device 14 can also be arranged in the instrument panel, roof structure, side structure or footwell of the vehicle.

[0025] The rotation angle sensor 16 is arranged to generate a signal dependent on the rotational movement of the seat belt shaft, from which the withdrawal length of the seat belt 5 from the seat belt shaft can also be determined directly by counting the rotations and angles of the seat belt shaft. The position sensor 15 is arranged below the deflection device 18 in the seat back 2 and its sensor field is oriented in such a way that when the seat belt 5 pivots about a pivot axis 21 oriented perpendicular to the seat back 2, a change in overlap generates a changing signal, making it possible to draw conclusions about the orientation of the seat belt 5. The signal changes make it possible to detect the orientation of the seat belt 5 in the directions towards the outside O, towards the inside I, upward U and downward D, as can be seen in the enlarged view of FIG. 1. Furthermore, the position sensor 15 is additionally designed to generate a changing signal when the distance A of the seat belt 5 to the position sensor 15, shown in FIG. 3, changes.

[0026] An advantage of the restraint device 4 according to the invention is that an incorrect fastening or even an unfastened seat belt 5 can be detected very easily and reliably by first detecting the unwinding process of the seat belt 5 via the signal of the rotation angle sensor 16 and then detecting the position and orientation of the seat belt 5 via the position sensor 15. A seat belt buckle sensor is therefore no longer necessary and cannot be avoided by simply inserting the seat belt tongue without the seat belt.

[0027] In this case, an incorrect fastening state of the seat belt 5 can be detected, in particular, by the position sensor 15 detecting an orientation and position of the seat belt 5 that is outside the range of orientation and position of the seat belt 5 specified for a proper fastening state.

[0028] Furthermore, the restraint device 4 according to the present invention can be used to perform very simple occupant classification, thereby enabling occupant-specific control of the restraint of an occupant in a restraint system according to the present invention having a controllable airbag device 14, a controllable force limiting device 12, and / or a controllable tensioning device.

[0029] For example, a tall occupant can be recognized by detecting an extended length of the seat belt 5 that is greater than a specified value, and the position sensor 15 detects a larger distance A, i.e., a larger angle, of the seat belt 5 compared to a predetermined distance A or angle relative to the seat back 2. Conversely, a small occupant can be detected when the extended length and distance A of the seat belt 5 are smaller than the predetermined values.

[0030] Similarly, an obese occupant with a large chest circumference can be distinguished from a lean occupant with a small chest circumference.

[0031] The position sensor 15 is arranged in the seat back 2 below the deflection device 18 and has its sensor field directed towards the upper side of the seat belt 5 facing the seat back 2. It detects the orientation of the seat belt 5 in the region of the diagonal seat belt sections 10 extending from the deflection device 18, which is crucial for restraining and leaning against the occupant's upper body. The arrangement and orientation of the diagonal seat belt sections 10 are particularly representative of the seat belt fastening state and the occupant's physical proportions, allowing for particularly accurate and reliable detection of the seat belt fastening state and physical proportions. This physical proportions are in turn crucial for the occupant's weight and shape, which are in turn crucial for the occupant's restraint, so that the occupant's restraint can be individually improved by suitable occupant-specific control of the airbag device 14, the force limiting device 12 and the tensioning device 13. In this case, occupant detection and seat belt fastening state detection are possible using only two sensors, namely the rotation angle sensor 16 and the position sensor 15, and the slight additional cost is offset by omitting the seat belt buckle sensor that was previously provided.

[0032] Furthermore, the restraint system additionally comprises a controllable acoustic and / or optical warning device 20 which is activated by a signal generated by the evaluation unit 17, which signal is in turn generated from the signals of the rotation angle sensor 16 and / or the position sensor 15, and which draws the occupant's attention to an incorrectly fastened or unfastened seat belt 5.

Claims

1. A restraint device (4) for an occupant seated on a vehicle seat (1) of a motor vehicle, comprising: a seat belt retractor (6), a frame that can be fastened so as to be fixed to the vehicle, and a seat belt retractor (6) comprising a seat belt shaft rotatably mounted in said frame; a seat belt (5) that can be wound at one end onto the seat belt shaft and that is guided over the occupant's shoulder to restrain him; Equipped with - a rotation angle sensor (16) is provided to detect the rotational movement of the seat belt shaft; and - a position sensor (15) is provided which generates a signal representative of the angle of travel of the seat belt (5) on the shoulder of the occupant; Restraint device (4).

2. a deflection device (18) is provided, in which the seat belt (5) is deflected towards the occupant; and - said position sensor (15) detects the position and orientation of said seat belt (5) after said deflection towards said occupant; A restraining device (4) according to claim 1.

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

4. A vehicle seat (1) according to claim 3, comprising a restraint device (4) according to claim 2, - the deflection device (18) is arranged in the upper edge portion (8) of the backrest (2), Vehicle seat (1).

5. Vehicle seat (1) according to claim 3 or 4, wherein the position sensor (15) detects the distance (A) of the seat belt (5) to the backrest (2).

6. A vehicle seat (1) according to any one of claims 3 to 5, wherein the position sensor (15) detects the angle (W) of the seat belt (5) relative to a pivot axis extending perpendicular to the backrest (2).

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

8. - a controllable airbag device (14) and / or a controllable force limiting device (12) and / or a controllable tensioning device (13) is provided, and - said airbag device (14) and / or said force limiting device (12) and / or said tensioning device (13) are controlled in response to said control signal; 8. The restraint system of claim 7.

9. - an acoustic and / or optical warning device (20) is provided, and - said optical and / or acoustic warning device (20) is activated in response to said control signal; 9. A restraint system according to claim 7 or 8.

Images