Patent Application
20050093685
1. Field of the Invention
The invention relates to an actuator device and safety mechanism for a motor vehicle. More specifically, the present invention relates to performing a function test with regard to triggering of a safety mechanism of a motor vehicle.
2. Description of the Related Art
German Patent Application DE 100 38 431 A1 discloses a power lock for a motor vehicle safety device. Various safety mechanisms for motor vehicles are known that, in the event of an accident, prevent injury to people involved in the accident, or attempt to restrict the gravity of injuries. For example, roll bars, headrests, knee pads, displaceable engine bonnets, displaceable steering wheels, or the like illustrate some of the safety mechanisms associated with automobiles.
The safety mechanisms are normally brought into their support position mechanically in the event of an accident, where the power or energy required to manoeuvre the mechanisms is made available by mechanical or pneumatic springs. Prior to an accident, the safety mechanisms of power locks are kept in a tensioned functional state, where high forces are maintained. The problem is that this type of power lock is rarely triggered, but triggering of the lock still needs to reliably function in an emergency, in particular, in the event of an accident.
An object of the present invention is to provide an actuator device, a safety mechanism for a motor vehicle, and an associated process for checking the operability of an actuator of an actuator device, to ensure secure triggering of the safety mechanism.
A basic aspect of the present invention is to operate or actuate an actuator of the actuator device to check its operability without triggering the safety mechanism. In this way, a check can be made to ensure that the actuator for releasing the safety mechanism actually functions. Accordingly, this increases reliability, and thus, safety in the event of an accident, since an essential functioning of the safety mechanism can be verified.
The actuator of the present invention is preferably operated during a function test counter to the direction of trigger and then is reset to its start position by means of a resilient force. This allows a very simple implementation that provides increased safety and reliability.
The function test is preferably carried out regularly and automatically. If the function test fails, repairs can be immediately made to the actuator device, so that the breakdown probability, in the event of an actual accident, at least is substantially reduced.
Further advantages, characteristics, properties and aspects of the present invention will emerge from the following description of a preferred embodiment with reference to the accompanying drawings.
The safety mechanism 2, in accordance with exemplary embodiments of the invention, can include a displaceable roll bar (
The actuator device 1 includes an actuator 3 and preferably an assigned gear 4. The actuator 3 can be operated or actuated in a triggering direction 5 to trigger the safety mechanism 2. The actuator 3 works preferably electrically and is designed, in particular, as an electromotor. If needed, the electromotor can be a linear drive, linear motor or an electromagnet, but it is preferably a motor generating revolutions.
In accordance with the present invention, during a function test, the actuator 3 is operated or actuated for checking its operability without triggering the safety mechanism 2. The actuator 3 is preferably operated in the function test counter to the triggering direction 5, until stops 6, 7 of the actuator device I limit further movement and/or a sensor device 8 (e.g., a Hall sensor or microswitch) has detected that backwards actuation or movement by the actuator 3 has occurred, and therefore the actuator 3 functions. Then, the actuator 3 and/or the gear 4 is preferably reset to a start position automatically through employment of a resilient force, after the actuator 3 is shut off. The actuator 3 is preferably short-circuited when reset. If needed, a generator current created by the actuator 3 or the short-circuit current can be detected and evaluated with respect to the operability of the actuator 3.
Alternatively or additionally, when the actuator 3 is running during the function test (i.e., when the actuator 3 is switched on) and/or when movement limits have been reached, such as overrunning the stops 6, 7, the actuator current can be detected and evaluated with respect to the operability and/or switching off of the actuator 3.
Also, the actuator 3 can be operated during the function test in the triggering direction 5, insofar as the gear 4 or the release mechanism has sufficient play and/or insofar as the actuator 3 and/or the gear 4 can be decoupled by means of a coupling (not illustrated) so that no unwanted triggering of the safety mechanism 2 occurs during the function test.
The gear 4 preferably has a worm gear pair 9 and/or an eccentric/lever combination 10. The worm gear pair 9 is preferably designed as non-self-locking, including a gear reduction ratio of at most 30:1. Additionally, in accordance with another exemplary embodiment, the gear reduction ratio can also be at most 25:1, as well as 20:1 or less.
A reset spring 11 is assigned to a worm wheel 12, driven by the actuator 3 by means of a worm 13. If required, the reset spring 11 is arranged on the axis 14 of the worm wheel 12 of the worm gear pair 9. This enables a particularly compact construction. If the reset spring 11 is arranged on the axis 14 of the worm wheel 12, relative movement between spring leg and worm wheel 12 is avoided. This increases the smooth running of the mechanics and reduces wear and tear on the actuator device.
In the example illustrated in
When the worm wheel 12 is rotated in the triggering direction 5, a further boss or cam 17, arranged on the worm wheel 12, engages on the stationary, housing-side stop 7 of the actuator device 1, so that the worm wheel 12 is blocked against further rotation in the direction of trigger 5. Thus, the end position or open position of the worm wheel 12 is fixed.
As already mentioned, the end position of the worm wheel 12 is fixed by the stop 6 in the illustrated example. Likewise, running up or stopping on the fixed stop 7 when turning against the direction of trigger 5 in the function test. In the example, the stops 6, 17 additionally form a radial engagement area for the reset spring 11. Here, other constructive solutions are also possible.
When opened, the detent pawl 16 is pivoted clockwise about the axis 18 in the illustrated example. The detent pawl 16 then releases an assigned rotary latch 19, so that the latter can pivot about a bearing axis 20 and can release an actuation element 21 of the safety mechanism 2 held in the locked or detained state. This release causes triggering of the safety mechanism 2. The detent pawl 16 is pre-tensioned, preferably by means of a spring 16a, into the detent position blocking the rotary latch 19 and thus the triggering of the safety mechanism 2. In the illustrated example, the spring is tensioned in a counterclockwise direction.
To prevent unwanted unlocking of the rotary latch and thus unwanted release of the safety mechanism 2, the detent pawl 16 can be blocked in the detent position by a boss or the like (not shown) arranged on the worm wheel 12, if the gear 4 or at least the worm wheel 12 is in the start position, therefore in a position of unwanted actuation. The gear 4 preferably has at least two gear stages, where the reset spring 11 preferably engages between the first and second gear stage or directly on the actuator 3 to ensure secure resetting. With only one gear stage, the reset spring 11 correspondingly engages directly on the actuator 3 or its driven component.
The advantage of resetting in the start position is that the starting position is determined relatively accurately in the event of triggering, so that defined and short actuation or trigger times can be achieved.
In the illustrated example, the worm gear pair 9 forms a first gear stage and the cam/lever combination 10 or the drive element 15 with the detent pawl 16, forms a second gear stage. With two gear stages, the gear reduction ratio of the driven-side gear stage preferably has at least 0.5 times the other gear stage. Additionally, the gear reduction ratio of the driver-side gear stage can also be at least 0.8 times, and more preferably, at least 1.0 times the other gear stage.
As already noted, the actuator 3, if the worm wheel 12 stops on the stop 7, can be switched off preferably depending on the actuator current.
Alternatively or additionally, the actuator 3 can also be switched off time-dependent, in particular after a preset time period has expired. This is particularly meaningful for the case where the function test is performed and the actuator 3 does not work. With such a failure or in another breakdown, a corresponding warning or error message is displayed for the motor vehicle user. The advantage of a microswitch is that it is cost-effective and enables simple control. For example, a Hall sensor provides greater reliability.
In the illustrated example, the sensor device 8 preferably has a microswitch. With the function test, the microswitch can be actuated, for example, by a boss 22 or the like, also positioned on the worm wheel 12. This allows the sensor device 8 to detect when the actuator 3 is working in the function test against the direction of trigger 5 and when the actuator 3 has moved the gear 4 or worm wheel 12 against the direction of trigger 5.
Immediately then, if needed, prior to running the stop 6 onto the stop 7, the actuator 3 can be switched off. Next, via the preferably non-self-locking worm gear pair 9, the worm wheel 12 and also the actuator 3 can be reset by the reset spring 11, back to the start position.
During the function test, the actuator 3 preferably rotates at least one full revolution to ensure uniform brush wear and/or uniform abrasion. In particular, the actuator 3 describes even several revolutions during the function test. The function test is preferably performed regularly and/or automatically, for example, after repeated opening, starting or locking of the motor vehicle, for example, after the 10th or 20th time or the xth time, where x is a predetermined or fixed number. It is especially preferred if the function test is performed as the motor vehicle is being locked. In this case, a motor vehicle user does not notice or hear the function test being run. In particular, the noises caused during the function test are drowned out or smothered by the noises occurring during locking.
The actuator device 1 is preferably assigned a control device 1a or electronics to enable corresponding control and evaluation or verification of the operability and, if needed, also triggering of the safety mechanism 2 in an emergency.
The actuator device 1 is preferably designed such that, after triggering, relocking is possible with moving or turning back the actuator 3, the gear 4, and the worm wheel 12, into the start position. In this way, a relocking is possible in a workshop only, for example, if the moving back is to be done manually.
As already noted, electronic evaluation or acknowledgement is preferably done to determine whether the actuator 3 is operable or not. In particular, detection of the operability during the function test is done by means of the sensor device 8. However, sensor device 8 is not absolutely required. As already mentioned, the operability of the actuator 3 can also be established, for example, by corresponding evaluation of the actuator current.
The non-self-locking design of the gear 4 or at least of the worm gear pair 9 provided in the illustrated example enables the gear 4 or worm gear pair 9 and the actuator 3 to be reset by resilient force, here by the reset spring 11.
With the preferably high gearing down in the second gear stage, on the contour of the drive element 15 acting on the detent pawl 16, it is possible to use a comparatively slight gear reduction in the worm gear pair 9. This is beneficial to improve device efficiency in the direction of trigger 5 and against the direction of trigger 5.
When the gear 4 or the actuator 3 is operated in a block mode, therefore switching on until stop 7 is reached, there is minimal control effort required. The provided short-circuiting of the actuator 3 during reset leads to the start position being reached more precisely. In addition, locking (not shown) of the gear 4 or of the worm wheel 12 can be obtained in the zero or start position, for example by a peripherally engaging detent tooth or the like. This allows obtaining the start position in a snap-in-mode. Thus, the start position is reached more precisely and also maintained, also with vibrations of the motor vehicle.
When the detent pawl 16 is blocked in its detent position by the worm wheel 12 in the start position or by another gear part, the detent pawl spring 16a can be configured to be less strong.
The safety mechanism 2 preferably has a spring actuator 23 which has the safety mechanism 2 activate its safety function after the actuation element 21 is released, and causes the provided displacement of a motor vehicle part 24 for protecting persons located both inside and outside the motor vehicle.
The motor vehicle part 24 is preferably a headrest, padding, a seat, a steering wheel, a safety net, a roll bar, a lock, a bonnet, a valve or a part thereof.
In the preferred embodiment shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 49 547.9 | Oct 2003 | DE | national |
