Patent Application
20240318475
This application is based on and claims priority under 35 U.S.C. § 119 to German Application No. 10 2023 106 832.6, filed on Mar. 20, 2023, the disclosure of which is incorporated by reference herein in its entirety.
Disclosed herein is a locking means (or locking apparatus) for a front flap (for example, a hood or a front trunk) of a motor vehicle, comprising a double-stroke lock that has a first and a second locking element for mechanically locking the front flap in a closed position.
The front flap of a motor vehicle is secured twice for safety reasons. In the actual closed position, the front flap is fully locked by a double-stroke lock. To unlock, a first locking element of the double-stroke lock, e.g. a pawl, must be actuated a first time, such that the front flap can be opened slightly and is secured in a pre-latched position by a second locking element, e.g. a catch hook. This pre-latched position ensures that the front flap, when the front flap has accidentally not been fully closed beforehand, cannot swing open when the vehicle is moving. To open the front flap completely, the locking element must be actuated a second time in order to release also the catch hook, such that the secured pre-latched position is also released. This double actuation is realized by a double-stroke lock.
Electrical positioning means are increasingly being used to perform mechanical positioning tasks. In the case of actuation of a double-stroke lock, since two separate lockings have to be released, two separate electrical positioning means, i.e. corresponding drive motors, must also be used in order to release, on the one hand, the locking in the locked position and, on the other hand, the locking in the pre-latched position. It would be expedient if only one positioning means were required to perform the separate unlocking operations. However, this requires a corresponding safety architecture, as it is necessary to avoid both locking stages being inadvertently unlocked by an incorrect or erroneous double actuation of the positioning means. It is conceivable to provide a separate control device for each unlocking stage, with one control device controlling the unlocking of the locked position and the other control device controlling the unlocking of the pre-latched position. Nevertheless, there is the problem that when the control device controlling the locked position accidentally operates a double actuation of the positioning means, the locking mechanism is inadvertently opened completely despite the safety architecture provided in respect of the control devices.
Disclosed herein is a locking apparatus for a front flap (e.g., a hood or a front trunk) of a motor vehicle. The locking apparatus for the front flap of the motor vehicle comprises a double-stroke lock that has a first locking element and a second locking element for mechanically locking the front flap in a closed position, which locking element can be unlocked by two separate strokes of an unlocking element, an actuator, coupled to the unlocking element, for moving the unlocking element for the purpose of unlocking the locking elements, a drive motor driving the actuator, a first control device and a second control device for separately controlling the drive motor, and a changeover element for changing over from the first control device to the second control device and vice versa, the drive motor being operable by the first control device for the purpose of moving the actuator to effect a first stroke, and the drive motor being operable by the second control device for the purpose of moving the actuator to effect a second stroke, the changeover element being controllable in dependence on the position of the actuator for the purpose of changing over.
The locking apparatus according to an example of the invention has, on the one hand, two separate control devices as a safety architecture, the first control device serving to effect the unlocking of the locked position by unlocking the first locking element, while the second control device serves to effect the unlocking of the pre-latched position by unlocking the second locking element. Both the first control device and the second control device control a common drive motor, which in turn drives an actuator, which in turn is coupled to an unlocking element by which the double-stroke lock can be actuated to unlock the two locking elements.
An element of the locking apparatus in this case is a changeover element, which serves to switch from the first control device to the second control device and vice versa, to ensure that only one control device is integrated into the actual control path at any one time. The changeover element in this case can be controlled in dependence on the position of the actuator for the purpose of changing over, i.e. a changeover from the first to the second control device and vice versa is dependent on the position of the actuator. The first control device in this case controls the drive motor for the purpose of moving the actuator to effect a first stroke, by which the first locking element, for example the pawl, is actuated, or unlocked, i.e. the locked position is unlocked such that the front flap moves into the pre-latched position. The second control device controls the drive motor for the purpose of moving the actuator to effect a second stroke, by which the second locking element is then actuated, or unlocked, such that the pre-latched position is unlocked by releasing of the second locking element, e.g. the catch hook. In an aspect of the present invention, the unlocking of the locked position is thus controlled exclusively by the first control device. When the locking has been released, the changeover element, on the basis of the position of the actuator that results from the unlocking, effects a changeover from the first control device to the second control device, such that only the latter can control a subsequent step. The first control device can consequently only control the unlocking of the locked position, i.e. only the first stroke, since the first control device is switched out of the control path immediately after the first stroke is performed. Any incorrect control by the first control device that would result in unlocking of the pre-latched position also is therefore precluded; this unlocking can only be controlled, for example, by the second control device.
The locking apparatus according to an aspect of the invention thus has an optimum safety architecture that prevents an inadvertent double actuation of the actuator, and thus an inadvertent execution of a double stroke, resulting from a control error.
For this purpose the drive motor may be controllable by the first control device for the purpose of moving the actuator from a neutral position, in a first direction, to effect the first stroke, as far as a first changeover position in which the changeover element can be actuated by the actuator to change over from the first control device to the second control device, whereupon the actuator can be restored to the neutral position, whereupon the drive motor controllable is by the second control device for the purpose of moving the actuator from the neutral position, in the first direction, to effect the second stroke, whereupon the drive motor can be restored to the neutral position. Once the actuator is moved from the neutral position into the changeover position as a result of control by the first control device, the first stroke is effected. At the same time as the changeover position is reached, switching is effected from the first control device to the second control device. The first control device is thus taken out of the control path and any control signal transmitted by the first control device would inevitably be ignored. Instead, the second control device is integrated into the control path. After the actuator has been restored to the neutral position, the second control device can operate the drive motor once again to effect a movement of the actuator from the neutral position, again in the first direction, to effect the second stroke. At the end of this control movement the actuator is again restored to the neutral position. The two strokes are thus effected by two separate movements of the actuator, each in the same first direction, the first movement being effected exclusively by the first control device, because the first control device is switched into the control path, while the second movement can be effected exclusively by the second control device, because the second control device is then switched into the control path.
Following unlocking of the pre-latched position, the changeover element effects switching, as described, to the second control device. As described above, however, the latter is not able to control the first stroke. In an aspect of the invention, this is only possible by the first control device. In order to now switch back to the first control device, an aspect of the invention provides that the drive motor can be controlled by the second control device to move the actuator from the neutral position, in a second direction, into a second changeover position in which the changeover element can be actuated by the actuator to change over from the second control device to the first control device, whereupon which the actuator can be restored to the neutral position. This second changeover operation, by which switching back is effected virtually back to the initial switching position in which the first control device is switched into the control path, is also effected solely in dependence on the position of the actuator. The second control device is integrated into the control path at the end of the second stroke, i.e. when the front flap is completely unlocked. The second control device is configured by its programming in such a way that, after the second stroke has been performed, the second control device operates the drive motor accordingly in order to move the actuator in a second direction, opposite to the first direction, and to bring the actuator into a second changeover position in which switching back from the second control device to the first control device is effected, i.e. the second control device is removed from the control path again and the first control device is reintegrated into the control path. In this way, the switching back operation can be controlled in a simple manner and again controlled solely through the position of the actuator, and the initial situation can be resumed.
Another aspect of the invention provides that the double-stroke lock can be actuated by a pull-shut element coupled to the actuator for the purpose of pulling the front flap shut. Therefore, not only the unlocking is effected fully automatically, but also the final pulling-shut of the front flap into the locked position. Provided for this purpose is a pull-shut element, which is coupled to the actuator and by which the double-stroke lock can be actuated in order to pull the front flap into the final locked position when the front flap is moved manually or automatically from the open position and past the pre-latched position in order to close it. The actuator is thus a multifunctional positioning element that is actuated both for unlocking and for pulling shut into the final locked position.
In another aspect of the invention, the pull-shut element can be actuated during the movement of the actuator in the second direction. As described, this actuator movement is controlled by the second control device in order to switch back from the second control device back to the first control device. This actuator movement is simultaneously used as an actuation movement for the pull-shut element, and thus for automatically pulling shut the front flap into the final locked position. Thus, while the movement of the actuator in the first direction serves to unlock the first and second locking elements, the movement of the actuator in the second direction serves to pull shut the front flap until the front flap is locked by the first locking element.
Both the changing-over and the corresponding actuation of the double-stroke lock are effected, as described, based on a movement of the actuator. The latter can be moved at least in a first direction, but preferably also in a second direction when an automatic pull-shut function is realized. This movement of the actuator may be realized with different actuator types. According to a first variant, the actuator may be a rotary actuator that can be rotated by the drive motor. Thus, when the drive motor is operated by the first or second control device, the motor rotates the rotary actuator about a corresponding axis of rotation, possibly by an interposed transmission. Alternatively, it is also conceivable for the actuator to be a linear actuator that can be moved linearly by the drive motor. In the case of this variant, the actuator thus executes a linear movement when the actuator is moved in the first direction and possibly also in the second direction. Both the rotary movement and the linear movement can easily be sensed accordingly in order to determine with precision when the respective changeover position is reached.
As described, the changeover from the first control device to the second control device and vice versa is effected in dependence on the position of the actuator when the changeover position is reached. This changeover may be effected either mechanically or contactlessly. For the purpose of sensing the position, two position elements that can be brought to be operatively connected to the changeover element, depending on the direction of movement of the actuator, may be provided on the actuator. These position elements are designed differently depending on whether mechanical or contactless position sensing is effected
When mechanical position sensing is effected, the position elements may be driver elements that can be brought mechanically to be operatively connected to the changeover element. For example, the actuator is provided with two projections that protrude from the actuator and form the driver elements. Depending on the direction of rotary or linear movement, one or other of the driver elements runs against the changeover element and actuates the changeover element to change over from the first to the second control device and vice versa
When contactless position sensing is effected, the position elements may be elements that can be sensed optically or electromagnetically, the position of which can be sensed by a sensing the changeover element. For example, corresponding position elements in the form of suitable markings that can be sensed photo-optically are provided on the actuator. A corresponding optical sensor system on the changeover element senses such a position element when the changeover position is reached, thereby indicating the changeover operation. As an alternative to optical sensing, electromagnetic sensing is also conceivable. In this case, for example, the position elements are in the form of metal elements that allow capacitive position sensing by a suitable sensor system on the changeover element when the respective changeover position is reached.
In a further aspect of the invention when a stop element is provided on the actuator, in which case there is provided at least one stop that is fixed in position, by which the movement of the actuator into the first changeover position is delimited. When necessary, a second stop, fixed in position, may also be provided, by which the movement of the actuator into the second changeover position is delimited. This stop function defines the respective changeover position and ensures that the corresponding changeover position is assumed in a defined manner at the end of the actuator movement and is also sensed.
As described, unlocking is effected by a double actuation of the double-stroke lock by the actuator and the unlocking element. In order to effect the first and second stroke, a Bowden cable is preferably provided as the unlocking element. This Bowden cable converts the rotary or linear movement of the actuator into a corresponding pulling movement, by which the respective stroke for actuation of the double-stroke lock to release the pawl in the first stroke, or the catch hook in the second stroke, is effected. A force sufficient for actuation can easily be effected by such a Bowden cable.
As described, unlocking is effected by double actuation of the double-stroke lock via the actuator and the unlocking element. To achieve the first and second stroke, a Bowden cable is preferably provided as the unlocking element. The rotary or linear movement of the actuator is converted into a corresponding pulling movement via this Bowden cable, via which the respective stroke for actuation of the double-stroke lock to release the pawl in the first stroke or the catch hook in the second stroke is achieved. A sufficiently high force for actuation can be easily achieved via such a Bowden cable.
In the same way, the pull-shut element, when one is provided, may also be in the form of Bowden cable. To pull shut, a force of appropriate magnitude must also be transmitted to the double-stroke lock so that the double-stroke lock can pull the front flap into the locked position with appropriate firmness and against the restoring force of any sealing elements and the like.
As described in the introduction, the actuator is in each case reset to the neutral position after a movement in the first and second direction. This restoration may be effected in different ways. It is conceivable for this restoration from the first and/or second changeover position to the neutral position to be effected by a spring element. In the case of a rotary actuator, such a spring element is, for example, a spiral spring. The spiral spring is compressed during a movement in the first direction, but is extended during a movement in the second direction. In either case, during each movement a restoring force is generated, which turns the rotary actuator back to the neutral position. In the case of a linear actuator, a coil spring is used, for example, as the spring element, although in this case two coil springs may also be used, with one resetting from the first direction and the other from the second direction.
As an alternative to the use of such mechanical restoring elements, it is also conceivable that the actuator can be returned from the first and/or the second changeover position to the neutral position, by the control device switched-in when the respective changeover position is reached, by operation of the drive motor. The first and the second control device are therefore programmed accordingly so that they can operate the corresponding restoring movement of the actuator, by operation of the drive motor, after the respective positioning movement in the first or second direction has been performed.
In addition to the locking apparatus, the invention also relates to a motor vehicle comprising both a front flap and a locking apparatus of the type described above.
These and other aspects and advantages will become more apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
The double-stroke lock 2 is a mechanical lock that, by two separate, successive strokes, enables the first locking element 3 to be unlocked first with a first stroke, and then the second locking element 4 to be unlocked with a second stroke. The basic structure and function of such a double-stroke lock 2 is known. In order to unlock the locking elements 3, 4, an unlocking element 5 is provided in the form of a Bowden cable 6, which can be actuated by an actuator 7 to effect the individual strokes. The actuator 7 is a rotary actuator 8 that can be rotated about an axis of rotation, this rotation being effected by a drive motor 9. There is a transmission 10 connected between the drive motor 9 and the rotary actuator 8. To actuate the Bowden cable, i.e. to pull the pull-cable to effect the respective stroke, the Bowden cable 6 is accommodated with a retaining nipple 11 in what is here an arcuate groove 12 of the rotary actuator 8.
Also provided is pull-shut element 13, which is also in the form of a Bowden cable 14. This pull-shut element 13 serves to automatically pull the front flap into the final closed position when the front flap is to be brought from the open position into the closed position, and then to lock the front flap, such that ultimately no manual action is required for this. This Bowden cable 14 is also mounted in the arcuate groove 12 by a retaining nipple 15, but is located at the other end of the groove 12, as shown in
The rotary actuator 8 furthermore has a first position element 16 in the form of a radially protruding projection, and a second position element 17, likewise in the form of a radially protruding projection, the two being diametrically opposite each other. These two position elements 16, 17 serve to actuate a changeover element 18 (or changeover apparatus 18), by which either a first control device 19 or a second control device 20 can be switched into the control path for the purpose of controlling the drive motor 9. The changeover element 18 in this case is configured in such a way that only one of the two control devices 19, 20 is switched-in to the control path at any one time, while the other is switched out of the control path.
Also provided on the rotary actuator 8 is a stop element 21, again protruding radially, to which are assigned the stops 22, 23, which are fixed in position and delimit the rotational movement of the rotary actuator 8 in a first direction I (clockwise) and a second direction II (anti-clockwise). The respective rotation delimitation coincides with the respective actuation of the changeover element 18, by the first or second position elements 16, 17, in the respective direction of rotation.
When the user wishes to open the front flap automatically, which is made possible by the locking apparatus 1, the user actuates an actuating element located in the vehicle interior, for example a pushbutton or similar, whereby the first control device 19 receives a corresponding signal that opening is required. The first control device 19 thereupon operates the drive motor 9 such that the latter rotates in a direction that causes the rotary actuator 8 to rotate in the first direction I, i.e. clockwise. This operation is shown in
Simultaneously with the rotation of the rotary actuator 8, the Bowden cable 6 is also pulled (see arrow P1), i.e. the unlocking element 5 is actuated, since, as shown in
As shown in
In the next step, the rotary actuator 8 reverses back to the neutral position. This backward movement is effected either by the decompressing spring element 24, with the drive motor 9 being switched off so that a reverse rotation is possible. Alternatively, it is also conceivable for the second control device 20 to be programmed in such a way that the second control device 20 operates the drive motor 9 to rotate backwards accordingly. In this case, the spring element 24 may be omitted. The restoration is effected by a rotation in the second direction II, i.e. anti-clockwise, as shown in
The front flap was unlocked by the first stroke and is now in the pre-latched position, which is fixed by the second locking element 4. In order to now fully unlock the front flap and also open this pre-latched position, the second control device 20 operates the drive motor again in order thereby to turn the rotary actuator 8 a second time in the first direction I, i.e. clockwise, as
The movement shown in
As explained, the first control device 19 is exclusively responsible for controlling the first stroke, while the second control device 20 is exclusively responsible for controlling the second stroke. Since the front flap is now unlocked and open, the front flap is closed again in the next step, and this closing operation can also be effected automatically until the final locked position is assumed. Once this final locked position has been reached again, for the next opening process there must necessarily be a changeover to the first control device 19
In order to effect this, after the performing of a closing operation of the front flap is sensed, for example by a suitable sensor system, the second control device 20 operates the drive motor 9 accordingly such that the drive motor 9 rotates the rotary actuator 8 in the second direction, anti-clockwise out, of the neutral position. In this situation, the front flap is already closed sufficiently far past the pre-latched position that the final closed position, in which the front flap is locked by the first locking element 3, can be assumed. This final closed position can be assumed automatically in that the front flap is actively pulled shut by the pull-shut element 13, i.e. the second Bowden cable 14. This closing operation (see arrow P3 in
With this rotary movement in the second direction II, the second position element 17 simultaneously runs in the direction of the changeover element 18 and, as part of this movement, runs against the switching element 25, which actuates the changeover element 18 when the switching element 25 assumes the end position shown in
In the next step, see
The schematic representations each show the actuator 7 as a rotary actuator 8. Alternatively, it is also conceivable for the actuator 7 to be realized as a linear actuator that can be moved linearly from a neutral position in a first direction and in an opposite second direction. The movement in the first direction, which in turn may be effected against the restoring force of a spring element such as a coil spring, effects the first and the second stroke for the purpose of unlocking the two locking elements 3, 4, while the movement in the opposite second direction, possibly again against a restoring element, serves to switch back from the second control device 20 to the first control device 19 (corresponding to
A description has been provided with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69 USPQ2d 1865 (Fed. Cir. 2004).
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 106 832.6 | Mar 2023 | DE | national |
