Motor vehicle lock

A motor vehicle lock has a pawl and a catch that may be moved into an open position, a preliminary latching position and a main latching position. In one of the latching positions, the catch is or may be brought into holding engagement with a lock striker. In the installed state, during a cinching routine, the catch is moved into its main latching position by a cinching drive. A spring biased freewheel mechanism, which is limited to a freewheel distance, is provided between the cinching drive and the catch. With the reaction force of the catch exceeding a predefined level, the cinching drive freewheels with respect to the catch against the spring bias of the freewheel mechanism, until the freewheel distance is reached and the freewheel mechanism is interlocked for force transmission.

FIELD OF THE TECHNOLOGY

The disclosure is directed to a method for operating a motor vehicle lock, to a motor vehicle lock arrangement and to a motor vehicle door arrangement.

BACKGROUND

The motor vehicle lock in question is assigned to a motor vehicle door arrangement, which comprises at least a motor vehicle door. The expression “motor vehicle door” is to be understood in a broad sense. It includes in particular side doors, back doors, liftgates, trunk lids or engine hoods. Such a motor vehicle door may generally be designed as a sliding door as well.

In order to increase the user-friendliness during closing of the motor vehicle door, today's motor vehicle locks are often equipped with a so-called cinching function. The cinching function provides a motorized movement of the catch of a motor vehicle lock from its preliminary latching position into its main latching position, which goes along with pulling the respective motor vehicle door from a preliminary door position into a main door position. This very last part of the closing movement of the motor vehicle door requires a considerable force against the door seals. This is why the cinching function is to be considered an important comfort feature.

The known motor vehicle lock (EP 1 617 021 B1), which is the starting point for the disclosure, represents a possible realization of the above noted cinching function. According to this it is known that the motor vehicle lock is provided with a cinching element and a cinching drive, such that, during a cinching routine, the catch may be moved into its main latching position by the cinching drive via the cinching element. The cinching routine is initiated by a manual movement of the catch into the preliminary latching position. This manual movement of the catch into its preliminary latching position goes back on the user moving the motor vehicle door manually into the preliminary door position.

While normally the above noted cinching function increases the user-friendliness in a very intuitive way, the cinching function also comprises a certain risk of injury. The reason for this is the fact that with the catch in its preliminary latching position, a certain gap between the motor vehicle door and the motor vehicle body remains. In case an object, finger or the like has been inserted into the gap, the full cinching force is applied to such means. This generally decreases the operational safety of the motor vehicle lock in question.

SUMMARY

It is therefore an object of some embodiments of the disclosure to improve the known motor vehicle lock such that the operational safety of the cinching function is increased with low constructional effort.

The above noted object is solved for a method as described herein.

The idea underlying the disclosure is to integrate a spring biased freewheel mechanism into the flux of force between the cinching drive and the catch in such a way, that a freewheel distance has to be overcome against the spring bias of the freewheel mechanism, before the freewheel mechanism interlocks and transfers large cinching forces. In case a user inserts a finger into the gap between the motor vehicle door and the motor vehicle body during the beginning of the cinching routine, the freewheel distance is run through against the spring bias of the freewheel mechanism. This means that during running through the freewheel distance the finger of the user experiences only those relatively low forces, which go back on the spring bias of the freewheel mechanism. Only after running through the freewheel distance, the full cinching forces are being applied to the door as the freewheel mechanism is being interlocked by that time. Being warned by the increasing but still relatively low force being exercised on its finger, the user will most probably pull out his finger before the time in which the freewheel mechanism is being interlocked.

In further detail it is proposed that between the cinching drive and the catch, a spring biased freewheel mechanism, which is limited to a freewheel distance, is provided. With the reaction force of the catch, which may go back on an object like a finger being inserted into the gap between the motor vehicle door and the motor vehicle body, exceeding a predefined level the cinching drive freewheels with respect to the catch against the spring bias of the freewheel mechanism, until the freewheel distance is reached and the freewheel mechanism is interlocked for force transmission. The proposed solution is an easy to realize way for warning the user that the cinching routine is running. This warning is done by running through the freewheel distance against the spring bias of the freewheel mechanism, such that the user has time to dissolve the collision situation, for example by pulling out his finger out of the gap between the motor vehicle door and the motor vehicle body.

In some embodiments, in the mounted state, the catch being moved from the preliminary latching position into the main latching position, corresponds to the gap between the motor vehicle door and the motor vehicle body decreasing from a preliminary gap to no gap. This means that the main latching position of the catch corresponds to the fully closed motor vehicle door.

The size of the preliminary gap is between 4 mm and 8 mm according to some embodiments, which may easily be closed by the cinching drive, which, however, also imposes a certain risk of a user inserting a finger into the gap.

According to various embodiments the predefined level of reaction force produced by the catch corresponds to a relatively low cinching force between the motor vehicle door and the motor vehicle body of less than 50 N and further of less than 20 N. This force is particularly low, taking into account that the maximum cinching force between the motor vehicle door and the motor vehicle body is between 250 N and 400 N.

Various embodiments are directed to the freewheel mechanism. According to some embodiments this freewheel mechanism is based on a pivotable force transmission lever, which pivot axis may be deflected against the spring bias of the freewheel mechanism. This kind of realization of the freewheel mechanism is particularly robust, as the force transmitting means are designed as pivotable means.

Various other embodiments are also directed to the freewheel mechanism. In this second embodiment the freewheel mechanism comprises two force transmission elements, that are coupled to each other with a play to the extend of the freewheeling distance, wherein both force transmission elements are spring biased against each other. This second embodiment is particularly easy to realize as a spring biased play requires only few components. According to some embodiments, the force transmission elements may be moved against each other along a linear path, which can be advantageous in view of integrating the freewheel mechanism into the drive train between the cinching drive and the catch. This can be particularly true for the various embodiments, in which at least one force transmission element is coupled to a bowden cable arrangement, which bowden cable arrangement provides the drive connection between the cinching drive and the catch.

The further embodiments are directed to the drive train between the cinching drive and the catch being designed as a self-locking drive train. The self-locking drive train can be advantageous in mechanical view, however, it can impose an additional risk of injury, as the motor vehicle door does not swing open in case of a loss of battery power or the like.

It may be pointed out that the cinching drive may be an integral part of the proposed motor vehicle lock. In some embodiments, this means that the motor vehicle lock comprises a housing which receives the cinching drive besides all other lock components. However, the cinching drive may also be realized separately from the motor vehicle lock. For example, the cinching drive may be drivingly connected to the motor vehicle lock by a bowden cable arrangement.

Various embodiments are directed to a motor vehicle lock arrangement as such. Here it is of particular importance that the motor vehicle lock and the cinching drive are both part of the motor vehicle lock arrangement. As noted above the cinching drive may be an integral part of the motor vehicle lock or may be realized separately from the motor vehicle lock.

Various embodiments include a motor vehicle door arrangement with a motor vehicle door and a motor vehicle lock arrangement as described herein. All explanations given with regard to the previous embodiments may be applied to all other embodiments.

Various embodiments provide a motor vehicle lock with a catch and a pawl, which is assigned to the catch, wherein the catch may be moved into an open position, into a preliminary latching position and into a main latching position, wherein the catch, which is in one of the latching positions, is or may be brought into holding engagement with a lock striker, wherein the pawl may be moved into an engagement position, in which it is in blocking engagement with the catch, and wherein the pawl may be moved into a release position, in which it releases the catch, wherein in the installed state, during a cinching routine, the catch is being moved into its main latching position by a cinching drive, wherein that between the cinching drive and the catch a spring biased freewheel mechanism, which is limited to a freewheel distance, is provided, that with the reaction force of the catch exceeding a predefined level the cinching drive freewheels with respect to the catch against the spring bias of the freewheel mechanism, until the freewheel distance is reached and the freewheel mechanism is interlocked for force transmission.

In various embodiments, in the mounted state, with the catch being moved from the preliminary latching position into the main latching position during the cinching routine, the gap between the motor vehicle door and the motor vehicle body decreases from a preliminary gap to no gap.

In various embodiments, the size of the preliminary gap is between 4 mm and 8 mm, such as 6 mm.

In various embodiments, in the installed state, the predefined level of reaction force produced by the catch corresponds to a pinching force between the motor vehicle door and the motor vehicle body of less than 50N, such as less than 20N.

In various embodiments, the freewheel mechanism comprises a force transmission lever, which is assigned a pivot bearing for pivoting around a pivot axis, wherein the pivot bearing of the force transmission lever comprises a play corresponding to the freewheel distance of the freewheel mechanism, which allows a translational deflection of the force transmission lever relative to the pivot axis and laterally with respect to the pivot axis or together with the pivot axis and laterally with respect to the pivot axis.

In various embodiments, the pivot bearing comprises a base section with a slot, which slot carries a bolt defining the pivot axis, wherein running through the freewheel distance corresponds to the bolt proceeding through the slot.

In various embodiments, the force transmission lever comprises a first lever arm, which in the installed state is connected to the cinching drive and that the force transmission lever comprises a second lever arm, which is connected to the catch during the cinching routine.

In various embodiments, during freewheeling, the reaction forces of the catch hold the second lever arm in place and the first lever arm is driven by the cinching drive, while the bolt is proceeding through the slot.

In various embodiments, the freewheel mechanism comprises a first force transmission element and a second force transmission element, that are coupled to each other with a play corresponding to the freewheeling distance and that the first force transmission element and the second force transmission element are spring biased against each other.

In various embodiments, the force transmission elements may be moved against each other along a linear path.

In various embodiments, in the installed state at least one force transmission element is coupled to a bowden cable arrangement.

In various embodiments, the drive train, that is assigned to the cinching drive, is designed as a self locking drive train.

Various embodiments provide a motor vehicle lock arrangement with a motor vehicle lock as described herein and a cinching drive connected to the motor vehicle lock.

Various embodiments provide a motor vehicle door arrangement with a motor vehicle door and a motor vehicle lock arrangement as described herein.

DETAILED DESCRIPTION

The motor vehicle lock1shown in the drawings is assigned to a motor vehicle door arrangement2, which comprises a motor vehicle door3besides the motor vehicle lock1. The motor vehicle lock1is designed for being operated by a lock control4.

Regarding the broad interpretation of the expression “motor vehicle door” reference is made to the introductory part of this specification. Here, the motor vehicle door3is a side door of a motor vehicle.

The motor vehicle lock1comprises the usual locking elements catch5and pawl6, which pawl6is assigned to the catch5. The catch5may be moved into an open position (FIG.2), into a preliminary latching position (FIG.3) and into a main latching position (FIG.5). The catch5, which is in one of the latching positions, is or may be brought into holding engagement with a lock striker7, as is shown inFIG.5for the example of the main latching position of the catch5.

Here, the motor vehicle lock1is arranged on the motor vehicle door3, while the lock striker7is arranged on the motor vehicle body8. This may be realized the other way around as well.

The pawl6may be moved into an engagement position, which is shown inFIG.3for the preliminary latching position and inFIG.5for the main latching position. In the engagement position, the pawl6is in blocking engagement with the catch5, preventing the catch5from moving into its opening direction. In addition, the pawl6may be moved into a release position, in which it releases the catch5, freeing the catch5to a movement into its opening direction. The wording “blocking engagement” is to be understood in a broad sense. It means that the pawl6is able to hold the catch5in its respective latching position. This can also include that the pawl6itself has to be engaged by another pawl in order to hold the catch5in its respective latching position.

Here the catch5is pivotable around the catch axis5a, while the pawl6is pivotable around the pawl axis6a. Generally there are other possibilities for realizing the movement of catch5and/or pawl6.

For realizing the above noted cinching function, a cinching drive9is provided. The cinching drive9may be integrated into the motor vehicle lock1. As an alternative, the cinching drive9may be realized separately from the motor vehicle lock1. In this alternative, the cinching drive9may be drivingly coupled to the motor vehicle lock1, in particular to the catch5, via a bowden cable arrangement or the like.

In any case, the catch5has to be drivingly coupled to the cinching drive9, such that the catch5may be driven by the cinching drive9during a cinching routine.

Here the cinching drive9is designed as a motorized drive. Accordingly, the cinching drive9can include a cinching motor10, which further can be realized as an electric motor. The electric motor can further include a rotational output shaft, which is drivingly coupled to a cinching element11, which transmits the force generated by the cinching drive9to the catch5.

During the cinching routine, the catch5is being moved into its main latching position by the cinching drive9via the cinching element11. For this, the cinching element11engages the catch5, as may be taken from the transition ofFIG.4toFIG.5. In some embodiments, the cinching routine includes moving the catch5from its preliminary latching position into its main latching position by the cinching drive9.

In some embodiments, the cinching routine is initiated in a very intuitive way. In detail, a manual movement of the catch5from the open position into the preliminary latching position causes the cinching routine to be initiated by the lock control4. The expression “manual movement” means, that the movement of the catch5in so far has been caused without the support of the cinching drive9. This manual movement of the catch5accordingly goes back on a closing movement of the motor vehicle door3from an open door position, which corresponds to the open position of the catch5, into a preliminary door position, which corresponds to the preliminary latching position of the catch5.

The lock control4monitors if a manual movement of the catch5from the open position into the preliminary latching position has taken place and accordingly causes the cinching routine to be initiated. For this, the lock control4can be control-wise coupled to a catch sensor12, which may be a simple micro switch or the like. Other possibilities for monitoring the catch movement are well applicable.

According to various embodiments, between the cinching drive9and the catch5a spring biased freewheel mechanism13is provided, which is limited to a freewheel distance14. The freewheel mechanism13allows a cinching movement of the cinching drive9over the freewheel distance14without the catch5following this movement. After running through the freewheel distance14the freewheel mechanism13interlocks, which interlocked state of the freewheel mechanism13is shown inFIG.5.

The above noted running through the freewheel distance14is performed against the spring bias of the freewheel mechanism13. The spring bias goes back on a spring arrangement15, which is assigned to the freewheel mechanism13.

During the cinching routine, with the reaction force of the catch5exceeding a predefined level the cinching drive9freewheels with respect to the catch5against the spring bias of the freewheel mechanism13, until the freewheel distance is reached and the freewheel mechanism is interlocked for force transmission. The sequence during normal operation may be taken from the sequence ofFIGS.3,4aand5.

The sequence of the cinching routine for a collision situation may be taken from the sequence ofFIGS.3,4band5. Interesting is the fact that inFIG.4bthe cinching drive9drives the cinching element11in a counter-clockwise direction without the catch5being moved at all. This is because the catch5is being blocked by an object in the gap between the motor vehicle door3and the motor vehicle body8, which object may be a finger of the user. As will be explained later, in this situation, the only force acting on the catch5and thereby on the motor vehicle door3is the force of the spring arrangement15shown inFIG.4b. As a result, even in the collision situation, an injury of the finger of the user is very unlikely.

Generally, in the mounted state, with the catch5being moved from the preliminary latching position into the main latching position during the cinching routine, the gap16between the motor vehicle door3and the motor vehicle body8decreases from a preliminary gap (FIG.3) to no gap (FIG.5).

The gap16is indicated in the drawings with reference No.16. The finger of the user is indicated inFIG.4bwith reference No.17.

The size of the preliminary gap16, which corresponds to the preliminary latching position of the catch5, can be between 4 mm and 8 mm, such as 6 mm. This shows that generally the insertion of a finger17of the user imposes a risk of injury.

In the installed state, the predefined level of reaction force produced by the catch5can correspond to a pinching force between the motor vehicle door3and the motor vehicle body8of less than 50 N, such as less than 20 N. This means that during running through the freewheel distance the risk of injury for the user is considerably reduced. The level of reaction force may easily be adjusted to a desired value just by a corresponding design of the spring arrangement15.

In the embodiment shown inFIGS.2to5the freewheel mechanism13comprises a force transmission lever18, which is assigned to a pivot bearing19for pivoting around a pivot axis20.

For freewheeling along the freewheel distance14, the pivot bearing19of the force transmission lever18comprises a play21corresponding to the freewheel distance14. The play21of the pivot bearing19allows a translational deflection of the force transmission lever18relative to the pivot axis20and naturally with respect to the pivot axis20. In an alternative (not displayed), the pivot bearing19may be designed such that the play21allows a translational deflection of the force transmission lever18together with the pivot axis20and laterally with respect to the pivot axis20.

As shown inFIGS.2to5the pivot bearing19comprises a base section22with a slot23, which slot23carries a bolt24defining the pivot axis20. The arrangement is such that running through the freewheel distance14corresponds to the bolt24proceeding through the slot23. Here the base section22with the slot23is part of the force transmission lever18, while the bolt24is fixed to the housing25of the motor vehicle lock1.

The force transmission lever18can include a first lever arm26, which in the shown installed state is connected to the cinching drive9. This connection between the cinching drive9and the force transmission lever18is realized by a bowden cable arrangement27, as indicated in the drawings as well.

In addition, the force transmission lever18comprises a second lever arm28, which is connected to the catch5during the cinching routine, as may be taken fromFIGS.4,5and6. For this connection the catch comprises an engagement section29in the form of a nose, which is in the path of movement of the second lever arm28of the force transmission lever18, at least when the catch5is in its preliminary latching position.

In the collision situation shown inFIG.4b, during freewheeling, the reaction forces of the catch5, which go back on the finger17inserted in gap16hold the second lever arm28in place, also the first lever arm26is still driven by the cinching drive9, while the bolt24is proceeding through the slot23. Until the bolt24reaches the end of the slot23, the pinching force between the motor vehicle door3and the motor vehicle body8is generated only by the spring arrangement15. Accordingly, if appropriately designed as noted above, the pinching during freewheeling is relatively low.

It is interesting that in the embodiment shown inFIGS.2to5, the force transmission lever18fulfills exactly the function of the above noted cinching element11. Here it becomes apparent that the freewheel mechanism13is integrated into the cinching element11which leads to an especially compact arrangement.

The second embodiment shown inFIG.6shows an identical behavior in view of the collision situation. The overall structure of the motor vehicle lock with the catch5and the pawl6, the lock control4is identical to the first embodiment shown inFIGS.2to4. However, the cinching element11is realized with a pivot bearing19, that does not provide the play noted above.

In the embodiment shown inFIG.6, the freewheel mechanism13is provided separately from the cinching element11. In further detail, the freewheel mechanism13shown inFIG.6comprises a first force transmission element30and a second force transmission element31, that are coupled to each other with a play32corresponding to the freewheeling distance14. The first force transmission element30and the second force transmission element31are spring biased against each other by a spring arrangement33. The result is that proceeding through the play i.e. freewheeling along the freewheeling distance14is possible only against the spring bias generated by the spring arrangement33.

The force transmission elements30,31shown inFIG.6may be moved against each other along a linear path, which makes it possible to integrate this freewheel mechanism13into an above noted bowden cable arrangement27.

In further detail,FIG.6ashows the normal operation of the motor vehicle lock1during the cinching routine. The freewheel distance14in this situation is yet to be run through. This will eventually take place when the motor vehicle door3engages the motor vehicle body8via the door seals.

FIG.6bshows the collision situation, in which a finger17of a user has been inserted into the gap16between the motor vehicle door3and the motor vehicle body8. Here, the reaction forces generated by the catch5are being transferred to the first force transmission element30via the cinching element11. This means that the first force transmission element30stops its movement, although the cinching drive9is still generating a movement. During this movement the second force transmission element31is proceeding through the play32against the spring bias of the spring arrangement33. This freewheeling is taking place until the freewheel mechanism13is interlocking. For this interlocking the first transmission element30comprises a blocking section34, which blocks further movement of the second force transmission element31, which leads to the freewheel mechanism13acting as a rigid force transmitting mechanism.

The drive train, that is assigned to the cinching drive9, can be designed as a self-locking drive train. This means that backdriving the cinching drive by introducing a force into the catch5is not possible. Here the proposed solution is of utmost importance in order to reduce the risk of injury for the user.

According to another teaching the motor vehicle lock arrangement can comprise the motor vehicle lock1and the cinching drive9connected to the motor vehicle lock1. Accordingly, all details given for the proposed method are fully applicable to this second teaching.

According to another teaching, which is of equal importance, the motor vehicle door arrangement2with a motor vehicle door3and the above noted motor vehicle lock arrangement is disclosed. Again, all details regarding the proposed method and regarding the proposed motor vehicle lock arrangement are fully applicable.

Just as a matter of completeness it may be pointed out, that in the opening direction of the catch5, the positions of the catch5are arranged in the order of main latching position, preliminary latching position and open position.

Finally it may be pointed out that generally the pawl6may be moved into its release position by manual actuation forces by the user. Here, however, an opening drive35is provided, which comprises an opening motor36for motorized moving of the pawl6into its release position. The opening drive35is being controlled by the lock control4just as the cinching drive9noted above.