Restraint system, vehicle seat and corresponding procedure

Abstract

Restraint system (10) for installation in a backrest (21) of a motor vehicle, wherein the restraint system (10) has an airbag (11), wherein the airbag (11) is designed to restrain an occupant behind the backrest (21), wherein the restraint system (10) has a radar sensor (12) which is designed to detect an occupant behind the backrest (21), characterized in that the airbag (11) and the radar sensor (12) are fastened to a belt retractor (13), and in that the belt retractor (13) forms a cross member for a rear seat (21).

Description

The present invention relates to a restraint system for installation in a backrest of a motor vehicle, to a corresponding backrest and to a corresponding method for controlling the restraint system.Design requirements imposed on occupant restraint systems on the rear seats of a motor vehicle are different from those imposed on driver and passenger restraint systems. Due to the possible occupant positions on the rear bench and the generally variable distance between the front seats and the rear seats due to the adjustability of the front seats in the vehicle longitudinal direction, very different conditions result, which make effective restraint of an occupant on a rear seat more difficult.DE 10 2021 102 814 A1 discloses a restraint system of the generic type. It enables occupant classification and with airbag deployment control based thereon. The system includes an interior sensor that is a camera, an ultrasonic sensor, a radar sensor, a lidar sensor, or an infrared sensor.It is therefore the object of the present invention to specify a restraint system for an occupant in a rear vehicle seat in a motor vehicle, which restraint system makes it possible to adapt to the respective conditions in the vehicle and the position of the occupant. Furthermore, the object of the invention is to specify a corresponding vehicle seat having a restraint system and a corresponding method for controlling.To achieve the object, a restraint system for installation in a backrest of a motor vehicle is proposed. The restraint system includes an airbag, the airbag configured to restrain an occupant behind the seatback. It is proposed that the restraint system has a radar sensor which is configured to detect an occupant behind the backrest.The arrangement of the radar sensor and the airbag in a restraint system allows detection of the occupant directly in front of the airbag, so that effective detection of the situation and the conditions in front of the airbag of the restraint system is made possible. The airbag for the occupant in a vehicle seat behind the restraint system or behind a vehicle seat with such a restraint system can thus be triggered adaptively according to the conditions. Different seat positions of the front vehicle seats can be compensated in this way, for example. Preferably, an electronic control unit is provided, which is configured to control and / or regulate the radar sensor and the airbag.In an advantageous specific embodiment, the radar sensor is situated next to the airbag. In this way, a particularly good assignment of the measured distance to the real conditions in front of the airbag, for example the distance of the occupant from the airbag before deployment, can be carried out. A very advantageous adaptive deployment behavior of the airbag can thus be achieved.According to the invention, it is proposed that the airbag and the radar sensor are fastened to a belt retractor. For example, the airbag, the radar sensor and the belt retractor can be provided in a module or else in a subassembly. This enables simple mounting in or on the backrest of a vehicle seat. The fastening to a belt retractor is preferably effected on the housing of a belt retractor. Furthermore, the airbag and the radar sensor are preferably arranged below the winding axis of a belt retractor in its installation position.In an embodiment according to the invention, the belt retractor, in particular a housing of the belt retractor, forms a cross member for a rear seat. Such a belt retractor can, for example, structurally connect two vertical structural elements of a backrest in the upper region of a backrest, such that the belt retractor becomes part of the seat structure itself. This enables a weight reduction and simplifies the structural integration of the airbag, in particular if the airbag and the radar sensor are fastened to the belt retractor.It is furthermore proposed that the restraint system has an electronic control unit which is set up to control the airbag, the radar sensor and the belt retractor. Therefore, the belt retractor for an occupant on a front seat, which uses the backrest into which the restraint system can be installed, and the radar sensor and the airbag for an occupant on a rear vehicle seat can be controlled using the same control unit using a control unit. This allows the number of control units and the necessary electrical and data connections to be reduced.The radar sensor is preferably configured to measure a distance from an occupant. This enables a particularly adaptive control of the restraint system, so that the deployment of the airbag can be deployed as a function of the measured distance.Furthermore, the airbag may be controllable as a function of the detected data of the radar sensor. Thus, adaptive control of the airbag, which is adapted to the respective conditions, can be achieved.Furthermore, in order to achieve the object of the invention, a vehicle seat for a motor vehicle having a backrest is proposed, wherein the backrest has a restraint system according to one of Claims 1 to 5.The advantages and features of the restraint system described above also apply to the vehicle seat having such a restraint system. An occupant in a vehicle seat behind the vehicle seat with the restraint system can therefore be protected by the airbag of the restraint system, wherein the airbag can be adaptively controlled on the basis of the radar sensor.Furthermore, in order to achieve the object of the invention, a method for controlling a restraint system according to one of Claims 1 to 5 is proposed. It is proposed that the ignition time of the airbag and / or the inflation behavior of the airbag is controlled over time and / or the inflation behavior of the airbag is controlled in geometry on the basis of the radar sensor. This allows for advantageous restraint with reduced occupant loads through the adaptive control of the airbag. The load may be reduced, for example, by an adjusted spark timing and / or adjusted pressure and / or size of the airbag.It is also proposed that the radar sensor detect the distance and / or the size of an occupant. The distance to an occupant refers to an occupant behind the restraint system that can be captured by the airbag in the inflated state. The detection of the size of an occupant enables a further improvement in the adaptive deployment of the airbag.The invention is explained below with reference to preferred embodiments with reference to the attached figures. This shows FIG. 1 shows a restraint system with an airbag, radar sensor and belt retractor on two vertical structural elements of a vehicle seat; and FIG. 2 shows a vehicle seat with a restraint system in the backrest with an inflated airbag in front of a rear vehicle seat.FIG. 1 schematically illustrates an advantageous exemplary embodiment of a restraint system 10 for a motor vehicle. The restraint system 10 is provided for installation in a backrest 21 of a vehicle seat 20, wherein the two vertical structural elements 22 of a backrest 21 are shown, on which the restraint system 10 is mounted in this advantageous exemplary embodiment.The restraint system 10 includes an airbag 11 that faces rearward toward a rear occupant. In addition to the airbag 11, a radar sensor 12 is provided, which is likewise directed rearward toward an occupant behind the restraint system 10 in the direction of travel.In this advantageous exemplary embodiment, radar sensor 12 and airbag 11 are mounted on a belt retractor 13, which forms a structural connection between vertical structural elements 22 of backrest 21. The restraint system 10 can be mounted together with the belt retractor 13 in a module on the vehicle seat 21, in particular the backrest 21 of the vehicle seat 20.In this advantageous exemplary embodiment, the restraint system 10 has a common electronic control unit 14 with the belt retractor 13, see also FIG. 2, which controls the functions of the restraint system 10 and of the belt retractor 13. Furthermore, in this exemplary embodiment, the belt retractor 13 and the restraint system 10 can be connected to the same electrical connection.Furthermore, the restraint system 10 can also have an electronic control unit 14, which controls only the functions of the restraint system 10.FIG. 2 shows the restraint system 10 in a vehicle seat 20 in a schematic side view. The restraint system 10 in the backrest 21 of the vehicle seat 20 is directed toward the rear seat 23 with the airbag 11 and the radar sensor 12. In the illustration of FIG. 2, the airbag 11 is shown in the deployed state.The restraint system 10 according to FIGS. 1 and 2 detects the distance from an occupant during operation with the radar sensor 12. Furthermore, by means of the distance measurement, it is also possible, for example, to determine whether an occupant is seated at all on the rear seat 23. Accordingly, the deployment behavior of the airbag 11 can be adaptively adjusted in the event of a crash. For example, the deployment timing, the depth of the airbag, and the inflation behavior of the airbag 11 may be adaptively controlled based on the detected radar data by the radar sensor 12.Furthermore, in a possible exemplary embodiment, a belt retractor for an occupant on the rear seat 23 can also be controlled in its load limiting curves by means of the captured data of the radar sensor 12, for example the distance from the radar sensor 12 to an occupant.

Claims

Restraint system (10) for installation in a backrest (21) of a motor vehicle, wherein the restraint system (10) has an airbag (11), wherein the airbag (11) is configured for restraining an occupant behind the backrest (21), wherein the restraint system (10) has a radar sensor (12) which is configured to detect an occupant behind the backrest (21), characterized in that the airbag (11) and the radar sensor (12) are fastened to a belt retractor (13), and in that the belt retractor (13) forms a cross member for a rear seat (21).Restraint system (10) according to Claim 1, characterized in that the radar sensor (12) is arranged next to the airbag (11).Restraint system (10) according to one of the preceding claims, characterized in that the restraint system (10) has an electronic control unit (14) which is set up to control the airbag (11), the radar sensor (12) and the belt retractor (13).Restraint system (10) according to one of the preceding claims, characterized in that the radar sensor (12) is designed to measure a distance from an occupant.Restraint system (10) according to one of the preceding claims, characterized in that the airbag (11) can be controlled as a function of the captured data of the radar sensor (12).Vehicle seat (20) for a motor vehicle having a backrest (21), characterized in that the backrest (21) has a restraint system (10) according to one of the preceding claims.Method for controlling a restraint system according to one of Claims 1 to 5, characterized in that the ignition time of the airbag (11) and / or the inflation behavior of the airbag (11) over time and / or the inflation behavior of the airbag (11) is controlled in the geometry on the basis of the radar sensor (12).Method for controlling a restraint system according to Claim 7, characterized in that the radar sensor detects the distance and / or the size of an occupant.

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