Motor vehicle locking device

Abstract

The invention relates to a motor vehicle locking device, in particular a motor vehicle lock and preferably a motor vehicle bonnet lock. The motor vehicle locking device is equipped with a locking mechanism (2, 3) which consists substantially of a rotary latch (2) and a pawl (3). Furthermore, a lock case (7) is provided for mounting the locking mechanism (2, 3). The lock case (7) is designed to be deformable in response to forces (F) that are acting thereon and those caused by acceleration, for example in the event of a crash. According to the invention, above a certain force (F) the deformable lock case (7) rests against the locking mechanism (2, 3) in order to increase a common section modulus.

Description

[0001] Description

[0002] Motor vehicle locking device

[0003] The invention relates to a motor vehicle locking device, in particular a motor vehicle lock and preferably a motor vehicle hood lock, with a locking mechanism consisting essentially of a rotary latch and a pawl, and with a lock case for supporting the locking mechanism, wherein the lock case is designed to be deformable in response to acting and acceleration-related forces, for example in the event of a crash.

[0004] In the event of a crash or an accident scenario, a motor vehicle and consequently also the associated vehicle locking system are subjected to significant accelerations and decelerations, corresponding to values ​​of several tens of g, with the acceleration due to gravity being the greatest. For this reason, both the lock case and the locking mechanism, which essentially consists of a rotary latch and pawl, are generally made of metal, particularly high-strength steel. This is because the vehicle locking system must ensure that doors, hoods, or even hatches secured against a body, for example, remain closed even in the event of an accident, in order to prevent people from being ejected from the vehicle. Furthermore, it is only when the vehicle doors are closed that the safety features installed there, such as side airbags, side impact protection, etc., can be guaranteed to be effective in protecting the vehicle occupants.

[0005] For this reason, the generic prior art according to EP 2 888 425 B1 involves equipping the rotational axes of the rotary latch and the pawl, for their mounting in the lock case, with a reinforcement plate spaced from the lock case and coupling them together. This allows for particularly large forces to be absorbed because the lock case, in conjunction with the reinforcement plate, provides a supporting structure with an overall rectangular cross-section. This has proven itself in principle, but is complex in terms of design and manufacturing.

[0006] In a comparable motor vehicle door lock according to DE 10 2019 108 967 A1, the lock case is equipped with at least one connecting bar that projects into a recess of an additional reinforcement element. The connecting bar engages the surrounding recess with a predetermined clearance to limit any possible deformation.

[0007] Alternatively, an additional component, such as a "structural rivet," can be used, which is permanently attached to the lock case. This additional component can absorb deformations of a locking pawl during an accident, as further explained in the state of the art according to DE 10 2016 218 229 A1.

[0008] The prior art has proven itself in principle, but is structurally complex and requires additional manufacturing and processing steps due to the additional reinforcement or connecting plates and reinforcement elements. The invention aims to remedy this situation.

[0009] The invention is based on the technical problem of further developing such a motor vehicle locking device such that high acting forces, for example in the event of a crash, can be easily and cost-effectively controlled without additional design effort. To solve this technical problem, a generic motor vehicle locking device within the scope of the invention is characterized in that, above a certain force, the deformable lock case engages the locking mechanism to increase a common moment of resistance.

[0010] The invention is based, first and foremost, on the realization that forces acting on a motor vehicle locking device, for example those associated with a crash, can typically result in the locking mechanism being deformed. This can be attributed to the fact that, when the associated motor vehicle door, hood, or hatch is closed, a locking bolt attached to the door, hood, or hatch in question is held in the locked position of the locking mechanism by the rotary latch, with the rotary latch in turn being secured by the pawl. If forces acting on the locking mechanism in question in its closed position caused by an accident then act on the rotary latch in particular via the locking bolt, these typically result in the rotary latch and, in particular, the locking mechanism as a whole being deformed via the locking bolt.In most cases, the acting forces result in tearing forces that act on the associated bearing pins with which the rotary latch or pawl is mounted on or in the lock case.

[0011] The anchoring of the bearing domes counteracts the forces with a specific moment of resistance, which is structurally provided by the locking mechanism. Within the scope of the invention, this moment of resistance, which the locking mechanism counteracts against the applied tensile forces, can be increased by causing the deformable lock case to press against the locking mechanism above a certain force (typically associated with a crash) to increase the joint moment of resistance. This means that the applied force not only deforms the locking mechanism or applies tensile forces to the bearing domes, but above a certain applied force, the lock case is also deformed.

[0012] According to the invention, the deformation of the lock case is adjusted so that the deformed lock case rests against the locking mechanism. This increases the combined moment of resistance, which results from the moment of resistance of the locking mechanism plus that of the lock case. As a result, the motor vehicle locking device according to the invention can absorb and control forces that are significantly greater than those that can be absorbed by the locking mechanism alone. This can be attributed to the combined effect of the locking mechanism and lock case in the event of a crash.

[0013] In fact, during normal operation, the locking mechanism and the lock case are spaced apart from each other, as otherwise friction-free operation of the locking mechanism during pivoting movements relative to the lock case around the respective bearing dome would not be possible. In the event of a crash, however, or when high acceleration or deceleration forces are applied, the locking mechanism is deformed on the one hand, and above a certain force threshold, the lock case also deforms. This occurs in such a way that the lock case overcomes the distance from the locking mechanism during normal operation and comes into contact with the locking mechanism. This gives the locking mechanism additional stiffening, and the locking mechanism and lock case work together, resulting in the desired increase in the now observed joint section modulus of the locking mechanism and lock case.All of this is achieved without additional structural measures such as reinforcement elements, reinforcement plates, etc., simply by adjusting the deformation of the lock case so that, above a certain threshold for the applied force, it is so great that, for example, the associated bulges in the lock case reach the locking mechanism and thus stiffen it. This is where the key advantages lie.

[0014] According to an advantageous embodiment, the design is additionally such that the locking mechanism is deformable up to a first force limit and, together with the likewise deformable lock case, reaches a higher second force limit. The first force limit can reach values ​​of approximately 4 kN to 6 kN, and preferably 5 kN. The second, higher force limit, in contrast, corresponds to values ​​of more than 9 kN up to approximately 12 kN, and preferably to values ​​of approximately 10.5 kN.

[0015] In any case, it is clear that the locking mechanism is initially deformed until the first force limit is reached, and is then able to absorb the forces acting, for example, in the event of a crash on its own. At even higher forces, the lock case is deformed to such an extent that it presses against the locking mechanism, further stiffening it. As a result, the combination of the deformed lock case and the resulting stiffened locking mechanism can absorb forces up to the second force limit. This allows virtually all crash situations and associated crash forces to be controlled without special design measures, and without any unintentional door, hatch, or hood opening occurring.

[0016] In fact, opening the hood of a motor vehicle, for example, should be avoided at all costs in the event of a crash for several reasons. First of all, the hood is needed to act as a "crumple zone" together with other structural elements of the body in the event of a frontal crash. Furthermore, an uncontrolled opening hood can not only impair the driver's view in the event of a crash, but can also potentially tip over and destroy a windshield, thereby posing an additional danger to vehicle occupants. In this respect, assuming and maintaining the closed position in the event of a crash is particularly important, especially for hoods. The same applies to tailgates and side doors.

[0017] Furthermore, the design is additionally such that the joint deformability of the locking mechanism in contact with the lock case and the lock case itself corresponds to an increase in the absorbable force of at least 50% and preferably 70% or more compared to the force absorption by the locking mechanism alone. This means that the combined effect of the deformed lock case in conjunction with the locking mechanism to stiffen it means that the forces absorbable by the locking device according to the invention can be increased by at least 50% and preferably 70% compared to the situation in which the lock case is not used to additionally stiffen the locking mechanism. In this respect, the lock case according to the invention, through its deformation in the event of a crash, takes on the function of additional reinforcing elements as described in the prior art and are obsolete according to the invention.

[0018] In addition, the design is such that the lock case and the rotary latch overlap to increase the shared moment of resistance when viewed from above. This means that once a certain force threshold is exceeded and thus a corresponding deformation occurs, the deformed lock case rests against the rotary latch and stiffens it. This results in the desired increase in the moment of resistance at this point because the rotary latch has captured the locking bolt, so that the tensile forces introduced into the rotary latch via the locking bolt meet the now increased moment of resistance caused by the deformed lock plate resting against it.

[0019] According to a further advantageous embodiment, the lock case is equipped with at least one guide element for mutual guidance relative to the rotary latch during deformation. This means that the guide element ensures that the deforming lock case is guided relative to the rotary latch during its deformation process, thus ensuring the desired engagement with the rotary latch. For this purpose and for cost reasons, it has proven particularly advantageous for the guide element to be designed as a bevel on the typically metallic lock case. Typically, the lock case, like the locking mechanism, is made of high-strength steel.

[0020] It has also proven effective for the guide element to overlap a stop leg of the rotary latch. In fact, the rotary latch usually has the stop leg in question and a catch leg, which are opposite each other and form a groove between them for the locking bolt.

[0021] Finally, it has proven particularly advantageous if the lock case has an L-shaped cross-section with a long L-leg and a short L-leg. The long L-leg is generally designed to form a deformable impact plate running transversely to the longitudinal extent of an associated vehicle. In contrast, the short L-leg describes a fastening plate coupled, for example, to a cross member of the vehicle. This means that the short L-leg or the fastening plate realized at this point generally ensures that the lock case is secured to the cross member of the vehicle. In contrast, the long L-leg and the deformable impact plate realized at this point act as a stiffener that can be applied to the locking mechanism in the event of a crash. For this purpose, the locking mechanism is usually mounted on the impact plate in question, whereas the fastening plate ensures that it is secured to the cross member of the vehicle.

[0022] The result is a motor vehicle locking system that is strikingly simple in its ability to absorb and control forces, particularly those that occur in a crash. This is achieved without the need for additional reinforcement plates or elements, simply because the deformed lock case rests against the locking mechanism to provide stiffening. This represents the key advantage.

[0023] The invention is explained in more detail below with reference to a drawing which merely represents an exemplary embodiment; in the drawings:

[0024] Fig. 1 shows an overview of the motor vehicle locking device according to the invention and

[0025] Fig. 2 shows a force-time diagram schematically illustrating the course of an accident.

[0026] Fig. 1 shows the motor vehicle locking device according to the invention, reduced to its essential elements. In fact, Fig. 1 shows the motor vehicle locking device, which according to the exemplary embodiment is designed as a motor vehicle lock and specifically as a motor vehicle hood lock. With the help of the motor vehicle hood lock shown in Fig. 1, it is possible to lock a front hood 1 of a motor vehicle (only indicated here) and to hold it closed in the closed position of an associated locking mechanism 2, 3. For this purpose, the front hood 1 has a locking bolt 4, which is held in a recess 5 of the rotary latch 2 in the closed position of the locking mechanism 2, 3 shown in Fig. 1.

[0027] In fact, the inlet mouth 5 of the rotary latch 2 is formed by the rotary latch 2 being fork-shaped and equipped with a stop leg 2a and a catch leg 2b. Additionally, an ejector element 6 can be seen, which is of no particular importance for the following considerations. The ejector element 6 is mounted coaxially with the pawl 3. In contrast, the rotary latch 2 has a bearing spaced apart from it. In both cases, the bearing is provided by respective bearing domes, which are anchored in a lock case 7 supporting the locking mechanism 2, 3.

[0028] The lock case 7 is designed to be deformable in response to acting and acceleration-related forces F, for example, in the event of a crash. The forces F in question are those that, as shown in Fig. 1 and by way of example, correspond to a frontal impact, i.e., they run in the longitudinal direction X of a motor vehicle indicated there.

[0029] It can be seen that the lock case 7 in the exemplary embodiment and in cross-section is L-shaped with a long L-leg 7a and a short L-leg 7b. The long L-leg 7a defines a baffle plate of the lock case 7. It can also be seen that the locking mechanism 2, 3 (and also the ejector element 6) are mounted on the long L-leg 7a or the baffle plate provided at this point. In contrast, the short L-leg 7b and the fastening plate realized at this point serve to secure the lock case 7 to a cross member of a motor vehicle (not shown in detail) - only indicated in Fig. 1.

[0030] If the frontal impact indicated in Fig. 1 occurs and the resulting force F acts on the motor vehicle hood lock shown in the drawing, the force F causes the locking mechanism 2, 3 to deform in the illustrated closed position. This is because the force F acts on the locking bolt 4 and causes tearing forces to act on the bearing pins of the locking mechanism 2, 3, which attempt to tear one or both bearing pins out of the lock case 7. The locking mechanism 2, 3, in conjunction with the bearing domes, counteracts this with a corresponding moment of resistance.

[0031] A temporal progression of the respective force F is shown in the diagram in Fig. 2. It can be seen that up to a first force limit Fi, predominantly the locking mechanism 2, 3 is increasingly deformed. In the range of this force limit Fi, the applied force F also deforms the lock case 7 as a whole. This applies particularly to the long L-leg 7a, which defines the impact plate. This means that, starting at a certain force F, which may be in the range of the first force limit Fi indicated in Fig. 2, the lock case 7 is increasingly deformed, specifically in the direction of the locking mechanism 2, 3.

[0032] As a result, starting at the relevant force, the deformed lock case 7 increasingly bears against the locking mechanism 2, 3 to increase a common moment of resistance. This means that the deformation of the lock case 7 corresponds to the fact that a distance required during normal operation between the lock case 7 or the long L-leg 7a and the locking mechanism 2, 3 is increasingly bridged by the deformation of the lock case 7 and in particular the long L-leg 7a.

[0033] In this way, the deformed lock case 7 bears against the locking mechanism 2, 3 and specifically the rotary latch 2, increasing with increasing force F. As a result, the locking mechanism 2, 3 is stiffened by the combinatorial effect together with the deformed lock case 7. The overall design is such that the locking mechanism 2, 3 is deformable up to the first force limit Fi and, together with the likewise deformable lock case 7, reaches a higher second force limit F2, as can be directly understood from the force-time diagram in Fig. 2. This also shows that the first force limit Fi is located at approximately 4 to 6 kN, whereas values ​​of more than 9 kN to approximately 12 kN are observed for the second force limit F2.

[0034] As a result, the joint deformability of the locking mechanism 2, 3 located in contact with the lock case 7 and of the lock case 7 leads to an increase in the force F resulting from the frontal impact by at least 50% compared to the situation in which the locking mechanism 2, 3 serves to absorb the force alone.

[0035] For this purpose, the design is additionally such that the lock case 7, or rather its long L-shaped leg 7a, and the rotary latch 2 overlap in plan view to increase the common section modulus. Furthermore, the lock case 7 has at least one guide element 7c, which serves to mutually guide the deformable lock case 7 and the locking mechanism 2, 3. According to the exemplary embodiment, the guide element 7c of the lock case 7 in question is a bevel 7c on the metallic lock case 7, which can therefore be manufactured particularly cost-effectively and quickly. Furthermore, the design is such that the guide element or bevel 7c engages over the stop leg 2a of the rotary latch 2.

[0036] This not only ensures that the lock case 7, or its long L-shaped leg 7a, is guided relative to the rotary latch 2 during its deformation due to the applied force F. This design also ensures that the rotary latch 2 and the pawl 3 remain engaged with each other even when the second force limit F2 is reached, thus maintaining the initial closed position. This also prevents the front hood 1 from opening accidentally, because the closed locking mechanism 2, 3 continues to hold the locking bolt 4 in its inlet opening 5. List of reference symbols:

[0037] 1 front hood

[0038] 2 rotary latch

[0039] 2a Stop leg

[0040] 2b Catch leg

[0041] 3 pawl

[0042] 2, 3 locking mechanisms

[0043] 4 locking bolts

[0044] 5 Inlet mouth

[0045] 6 Ejector element

[0046] 7 Lock case

[0047] 7a long L-leg

[0048] 7b short L-leg

[0049] 7c Guide element / bend

[0050] F forces

[0051] Fi first force limit

[0052] F2 second force limit

[0053] X Longitudinal direction

Claims

Patent claims 1. Motor vehicle locking device, in particular motor vehicle lock, preferably motor vehicle hood lock, with a locking mechanism (2, 3) consisting essentially of a rotary latch (2) and a locking pawl (3), and with a lock case (7) for storing the locking mechanism (2, 3), wherein the lock case (7) is designed to be deformable in response to acting and acceleration-related forces (F), for example in the event of a crash, characterized in that, from a certain force (F), the deformable lock case (7) applies itself to the locking mechanism (2, 3) to increase a common resistance moment.

2. Device according to claim 1, characterized in that the locking mechanism (2, 3) is deformable up to a first force limit (Fi) and, together with the also deformable lock case (7), achieves a higher second force limit (F2).

3. Device according to claim 2, characterized in that the first force limit (Fi) is set at approximately 4 to 6 kN, preferably 5 kN.

4. Device according to claim 2 or 3, characterized in that the second force limit (F2) is a value of more than 9 kN up to approximately 12 kN, preferably approximately 10.5 kN.

5. Device according to one of claims 1 to 4, characterized in that the joint deformability of the locking mechanism (2, 3) located in the arrangement on the lock case (7) and of the lock case (7) leads to an increase the absorbable force (F) of at least 50%, preferably 70% and more, corresponds to the force absorption solely by the locking mechanism (2, 3).

6. Device according to one of claims 1 to 5, characterized in that the lock case (7) and the rotary latch (2) overlap in top view to increase the common resistance moment.

7. Device according to one of claims 1 to 6, characterized in that the lock case (7) is equipped with at least one guide element (7c) for mutual guidance relative to the rotary latch (1) in the event of deformations.

8. Device according to claim 7, characterized in that the guide element (7c) is designed as a bend (7c) on the lock case (7).

9. Device according to claim 7 or 8, characterized in that the guide element (7c) overlaps a stop leg (2a) of the rotary latch (2).

10. Device according to one of claims 1 to 9, characterized in that the lock case (7) has an L-shaped cross-section with a long L-leg (7a) and a short L-leg (7b), wherein the long L-leg (7a) defines a deformable impact plate extending transversely to the longitudinal extent of a vehicle and the short L-leg (7b) defines a mounting plate coupled, for example, to a cross member of the motor vehicle.

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