VEHICLE STEERING WHEEL SYSTEM WITH AN ENERGY-SAVING ELECTROMECHANICAL TRIGGERING DEVICE FOR TRIGGERING AN ACOUSTIC OUTPUT

Abstract

A vehicle steering wheel system is provided. The system includes a steering wheel body with a hub region for attachment to a steering shaft of a vehicle steering system, a steering wheel rim and at least one spoke for attaching the steering wheel rim to the hub region; an electromechanical triggering device for triggering an acoustic output by means of an acoustic warning device of the vehicle, wherein the triggering device has an impact absorber cover and at least one force transducer wherein a force value threshold is predefined for each force transducer, and a wake-up signal is transmitted via the data connection to the evaluation unit if the force value threshold is exceeded by at least one force value, so that the latter changes from the energy-saving mode into the operating mode in which an actuating force value is determined by force value measured by the at least one force transducer.

Claims

1. A vehicle steering wheel system, comprising: a steering wheel body with a hub region for attachment to a steering shaft of a vehicle steering system, with a steering wheel rim and with at least one spoke for attaching the steering wheel rim to the hub region; an electromechanical triggering device for triggering an acoustic output by an acoustic warning device of the vehicle, wherein the electromechanical triggering device has an impact absorber cover, which is disposed on the steering wheel body and covers the hub region at least partially while forming an actuating surface, wherein the impact absorber cover is mounted on the steering wheel body so as to be at least one of displaceable, in an elastically self-resetting manner, under the influence of an actuating force on the actuating surface in the direction of the hub region, and deformable, in an elastically self-resetting manner, in the direction of the hub region; wherein the electromechanical triggering device further has at least one force transducer, which is disposed between the impact absorber cover and the steering wheel body and via which the impact absorber cover is supported on the steering wheel body, for measuring a force value that can be associated with the actuating force acting on the actuating surface of the impact absorber cover; wherein the electromechanical triggering device further has, for each of the at least one force transducer, an electronic evaluation system connected in an electrically conductive manner to the respective at least one force transducer and an evaluation unit, which is superordinate to the electronic evaluation system or systems and can be selectively operated in an energy-saving mode and an operating mode, wherein the electronic evaluation system is connected to the evaluation unit via at least one data connection in each case, wherein a force value threshold is predefined for each of the at least one force transducer and a wake-up signal is transmitted via the at least one data connection to the evaluation unit exclusively if the force value threshold is exceeded by at least one force value, so that the latter changes from the energy-saving mode into the operating mode in which an actuating force value is determined by means of the force value measured by the at least one force transducer in order to trigger the acoustic output of the acoustic warning device of the vehicle when a predefined actuating force value is exceeded.

2. The vehicle steering wheel system according to claim 1, wherein the force transducer or force transducers are eccentrically disposed relative to the steering shaft.

3. The vehicle steering wheel system according to claim 2, wherein several force transducers distributed around the steering shaft, each with an associated electronic evaluation system, are provided that are each connected to the evaluation unit via at least one data connection.

4. The vehicle steering wheel system according to claim 1, which further comprises an airbag initiation device, and the impact absorber cover is configured so as to bridge an accommodating space, which is provided between the hub region and the impact absorber cover and provided for at least partially accommodating the airbag initiation device.

5. The vehicle steering wheel system according to claim 1, wherein further all electronic evaluation systems can be selectively operated in an energy-saving mode and an operating mode, and a change of the electronic evaluation systems from, in each case, the energy-saving mode into the operating mode is triggered by the evaluation unit.

6. The vehicle steering wheel system according to claim 1, wherein the at least one force transducer measures the force value optically, capacitively, inductively or resistively in each case.

7. The vehicle steering wheel system according to claim 1, wherein the evaluation unit is configured such that the change from the energy-saving mode into the operating mode is preceded in time by a change from the operating mode into the energy-saving mode, and the change from the operating mode into the energy-saving mode is triggered by each force value having dropped below one predefined switch-off force threshold in each case.

8. The vehicle steering wheel system according to claim 1 is used in a vehicle.

9. A method for triggering an acoustic output by an acoustic warning device of the vehicle, comprising: providing a vehicle steering wheel system, with a steering wheel body comprising a hub region for attachment to a steering shaft, a steering wheel rim and at least one spoke for attaching the steering wheel rim to the hub region, with an electromechanical triggering device for triggering the acoustic output by means of the acoustic warning device of the vehicle, wherein the triggering device has an impact absorber cover, which is disposed on the steering wheel body and covers the hub region at least partially while forming an actuating surface, wherein the impact absorber cover is mounted on the steering wheel body so as to be at least one of displaceable, in an elastically self-resetting manner, under the influence of an actuating force on the actuating surface in the direction of the hub region, and deformable, in an elastically self-resetting manner, in the direction of the hub region; wherein the electromechanical triggering device further has at least one force transducer, which is disposed between the impact absorber cover and the steering wheel body and via which the impact absorber cover is supported on the steering wheel body; and the electromechanical triggering device further has, for each of the at least one force transducer, an electronic evaluation system connected in an electrically conductive manner to the at least one force transducer and an evaluation unit, which is superordinate to the electronic evaluation system or systems and can be selectively operated in an energy-saving mode and an operating mode, wherein the electronic evaluation system is connected to the superordinate evaluation unit via at least one data connection in each case, wherein a force value threshold is predefined for each of the at least one force transducer; measuring a force value, which can be associated with an actuating force acting on the actuating surface of the impact absorber cover, by means of the at least one force transducer; comparing the force value to the force value threshold, wherein a wake-up signal is transmitted via the at least one data connection to the evaluation unit exclusively when the force value threshold is exceeded by at least one force value; changing from the energy-saving mode into the operating mode if the wake-up signal is received by the evaluation unit; subsequent operation of the evaluation unit in the operating mode, in which an actuating force value is determined by means of the force value measured by the at least one force transducer; when a predefined actuating force value is exceeded by the actuating force value, causing the triggering of the acoustic output of the acoustic warning device of the vehicle by the evaluation unit.

10. The method according to claim 9, wherein further all electronic evaluation systems can be selectively operated in an energy-saving mode and an operating mode, and at least one change of the electronic evaluation systems from, in each case, the energy-saving mode into the operating mode is triggered by the evaluation unit.

11. The method according to claim 9, wherein the at least one force transducer measures the force value optically, capacitively, inductively or resistively in each case.

12. The method according to claim 9, wherein the change from the energy-saving mode into the operating mode is preceded in time by a change from the operating mode into the energy-saving mode, and the change from the operating mode into the energy-saving mode is triggered by each force value having dropped below one predefined switch-off force threshold in each case.

13. The method according to claim 10, wherein the at least one change of the electronic evaluation systems from, in each case, the energy-saving mode into the operating mode is triggered by the evaluation unit prior to the actuating force value being determined in the operating mode of the evaluation unit.

14. The method according to claim 12, wherein the change from the operating mode into the energy-saving mode is triggered by the actuating force value having dropped below a predefined switch-off actuating force threshold.

15. The method according to claim 12, wherein the change from the operating mode into the energy-saving mode is triggered by the actuating force value having dropped below a predefined switch-off actuating force threshold in each case for a predefined duration.

16. The vehicle steering wheel system according to claim 7, wherein the change from the operating mode into the energy-saving mode is triggered by the total of all force values having dropped below one predefined switch-off total force threshold in each case.

17. The vehicle steering wheel system according to claim 7, wherein the change from the operating mode into the energy-saving mode is triggered by the total of all force values having dropped below one predefined switch-off total force threshold in each case for a predefined duration.

Description

[0032] The various embodiments as well as the technical environment will be explained in more detail below with reference to the Figures. It must be remarked that the Figures depict a particularly preferred embodiment of the disclosed embodiments, but that the disclosed embodiments are not limited thereto. In the Figures:

[0033] FIG. 1 shows a schematic top view or view through an embodiment of the vehicle steering wheel system;

[0034] FIG. 2 shows a schematic horizontal sectional view of the embodiment shown in FIG. 1;

[0035] FIG. 3 a schematic depiction of the method according to an embodiment.

[0036] The vehicle steering wheel system 1 according to the embodiment includes a vehicle steering wheel body 2 and an electromechanical triggering device 7. The latter comprises an impact absorber cover 8 disposed on the steering wheel body 2. The steering wheel body 2 comprises a central hub region 2b serving for non-rotatably fixing the steering wheel body 2 to a steering shaft 10, which is usually arranged in a steering column. The steering wheel body 1 further comprises an annular steering wheel rim 2a, which is attached to the hub region 2b via several spokes 2c. To an operator operating the vehicle steering wheel system 1, the impact absorber cover 8 is arranged on the side of the steering wheel body 2 facing towards him in such a way that the impact absorber cover 8 covers the hub region 2b. Under the impact absorber cover 8 and between the latter and the steering wheel body 2, more specifically between the impact absorber cover 8 and the hub region 2b, three force transducers 3a, 3b, 3c are disposed, which respectively determine a force value and which further serve for movably mounting, in an elastically self-resetting manner, the impact absorber cover 8 on the hub region 2b of the steering wheel body 2.

[0037] The force transducer 3a, 3b, 3c associated with the electromechanical triggering device 7 serve for the actuation force-dependent triggering of an acoustic output, also called horn signal, by an acoustic warning device of the vehicle, which is not depicted. For example, these are optical, capacitive, inductive or MEMS force sensors 3a, 3b, 3c. The force transducers 3a, 3b, 3c each have an associated electronic evaluation system 4a, 4b and 4c, wherein the latter are connected to a superordinate evaluation unit 9 via a bus (e.g. I2C) as a data connection 5a, 5b, 5c. Moreover, each of the electronic evaluation systems 5a, 5b, 5c is connected via an interrupt line 6a, 6b, 6c to the evaluation unit 9 in order to be able to transmit a wake-up signal from the electronic evaluation systems 4a, 4b, 4c to the evaluation unit 9 or vice versa. The electronic evaluation systems 4a, 4b, 4c transmit the force values measured by the force transducers 3a, 3b, 3c in each case via the bus 5a, 5b, 5c to the evaluation unit 9. The latter can be selectively operated in an energy-saving mode and an operating mode, wherein the change from the energy-saving mode into the operating mode can be triggered by receiving at least one wake-up signal via the interrupt lines 6a, 6b, 6c. If the evaluating unit 9 is operated in the operating mode, the force values are then processed electronically, and an actuating force is determined as a total force, as well as, optionally, the location of the action of the actuating force. If this is greater than an actuating force threshold value predefined for triggering, the vehicle horn is activated, e.g. by means of a signal via the vehicle bus or hard wiring.

[0038] In order to save energy, at least the evaluation unit 9 and preferably also the electronic evaluation systems 4a, 4b, 4c of the force transducers 3a, 3b, 3c, e.g. in the case of a switched-off “ignition”, are operated in the energy-saving mode, also referred to as “sleep mode”. This means, for instance, that only a few basic functions of the respective component are active. In the sleep mode, for example, the electronic evaluation systems 4a, 4b, 4c are operated in such a manner that the interval in time of the force value determination is increased in the energy-saving mode as compared with the operating mode. Preferably, the energy-saving mode is characterized in that no data exchange takes place between the force transducers 3a, 3b, 3c and the evaluation unit 9 via the bus 5a, 5b, 5c. FIG. 2 shows a section through the vehicle steering wheel system 1 according to the embodiment. As is shown therein, the impact absorber cover 8 is configured so as to bridge an accommodating space 12, which faces towards the hub region 2b and in which an airbag initiation device 11 is accommodated. The airbag initiation device 11 is fixed to the hub region 11. The method for triggering an acoustic output by an acoustic warning device of the vehicle is explained with reference to the schematic depiction of FIG. 3. In the step denoted “Start”, a vehicle steering wheel system, as it was described with reference to FIGS. 1 and 2, for example, is provided. In step S1, it is in the energy-saving mode. One force value threshold is predefined for each force transducer 3a, 3b, 3c from FIG. 1. If, in step S2, this force value threshold is exceeded in the energy-saving mode by one of the force values determined by the force transducers 3a, 3b, 3c from FIG. 1, then a wake-up signal is transmitted via the interrupt lines 6a, 6b, 6c of FIG. 1 to the evaluation unit 9 in step S3. In step S4, the latter changes from the energy-saving mode into the operating mode and in step S5 activates all electronic evaluation systems 4a, 4b, 4c of the force transducers 3a, 3b, 3c by means of a corresponding wake-up signal via the bus 5a, 5b, 5c, in order to initiate a measurement and transmission of the associated force values to the evaluation unit 9 in step S6. In step S7, the latter determines the actuating force F; if that is greater than the actuating force value threshold F.sub.Schwelle in step S8, then the horn, i.e. the acoustic warning signal, is activated. In the event the actuating force threshold F.sub.Schwelle is not exceeded for a predefined duration, the electronic evaluation system 9, and in particular the electronic evaluation systems 4a, 4b, 4c, are returned to the energy-saving mode.