Lock, in particular tailgate lock, for a motor vehicle

Abstract

The invention relates to a lock (1), in particular a tailgate lock, for a motor vehicle, comprising a locking mechanism (3) which has a rotary latch (7) and at least one pawl (8), the rotary latch (7) being latchable in a preliminary latching position and a main latching position by means of the pawl (8), and comprising a closing drive (2) which has an electric motor (9) and at least one gear stage having a drive pinion (11) and an output pinion (12), wherein the locking mechanism (3) can be transferred from a preliminary latching position into a main latching position and an overtravel position by means of the closing drive (2), and a closing pawl (6) and the rotary latch (7) are in rolling contact with one another in the engagement region (13).

Description

[0001] Applicant: Kiekert AG 02.03.2026 Our reference: P24135WO

[0002] Lock, especially tailgate lock, for a motor vehicle

[0003] Description

[0004] The invention relates to a lock, in particular a tailgate lock, for a motor vehicle, comprising a locking mechanism with a rotary latch and at least one pawl, wherein the rotary latch can be locked in a pre-latching position and a main latching position by means of the pawl, a closing drive, wherein the locking mechanism can be moved from a pre-latching position to a main latching position and an overtravel position by means of the closing drive, and an electric drive unit associated with the closing drive with at least one gear stage.

[0005] Modern motor vehicles increasingly incorporate electrically assisted operating and functional elements. These assistance systems make it easier for the user to operate the vehicle and can, for example, make getting in and out more comfortable. The present invention relates to a motor vehicle locking device, which can be used in particular in doors or tailgates to move a partially closed door element from a pre-latch position to a fully closed position, a so-called main latch position. It is already common practice to equip such locking devices with electric drives that enable the automatic closing of the door or tailgate.

[0006] For example, it is known from DE 102023 101 262 A1 to equip a motor vehicle lock with an electric closing and opening drive. Such a motor vehicle lock typically has a rotary latch that can be moved into a pre-latch position and a main latch position. In the closed position, the rotary latch engages a locking bolt or a lock holder, which can be attached to a vehicle body, for example. The rotary latch engages with a pawl, which secures the rotary latch against rotation in the pre-latch and main latch positions by means of positive locking. Functional elements of the drive unit act on the pawl of the motor vehicle lock via a pawl mechanism. This allows the pawl to be moved by the drive element around a rotational axis of the pawl, thereby unlocking the rotary latch, for example.

[0007] From DE 102021 100462 A1 a motor vehicle lock has become known which comprises a locking mechanism with a rotary latch and a pawl, as well as a pull-type P24135

[0008] and an opening drive and a lever chain actuated by it. The rotary latch is moved by the closing drive via the lever chain from the pre-latch position to the main latch position.

[0009] German patent DE 20 2017 104 891 U1 describes a locking system for vehicle doors with various interacting levers, some of which have an involute toothed surface. The document explains that the involute toothed surface is designed to prevent "cutting" and to reduce noise and wear.

[0010] The locking systems according to the invention employ lever chains by which the rotary latch can be moved from the pre-latching position to a main latching position. These lever chains represent a complex kinematic mechanism, which is also subject to friction between the individual lever elements and at the contact point with the rotary latch, and is therefore subject to wear. Furthermore, the sliding movements in the lever chains generate noise. This is where the invention comes in.

[0011] The object of the invention is to provide an improved motor vehicle lock. Furthermore, it is an object of the invention to provide a motor vehicle lock in which the kinematics between the closing drive are designed to be as simple and low-friction as possible. At the same time, it is an object of the invention to provide a cost-effective solution for the aforementioned kinematics.

[0012] The problem is solved by the features of independent claim 1. Advantageous embodiments are specified in the dependent claims. It should be noted that the exemplary embodiments described below are not limiting; rather, any number of variations of the features described in the description and the dependent claims are possible.

[0013] According to claim 1, the object of the invention is achieved by providing a lock, in particular a tailgate lock, for a motor vehicle, comprising a locking mechanism with a rotary latch and at least one pawl, wherein the rotary latch can be engaged in a pre-engagement position and a main engagement position by means of the pawl, a closing drive, wherein the locking mechanism can be moved from a pre-engagement position to a main engagement position and an overtravel position by means of the closing drive, or vice versa, and an electric drive unit associated with the drive, comprising at least one gear stage, as well as a closing pawl of the closing drive, which has a rolling contact in a contact area between the closing lever and the rotary latch. The design as a rolling contact achieves a P24135

[0014] The invention ensures low-wear or virtually wear-free and quiet or nearly silent operation of the rotary latch. In the engagement or contact area between the rotary latch and the closing lever, a rolling motion occurs; in other words, the closing lever rolls along the rotary latch during the closing process. This prevents the components in engagement from sliding along the contact area. Furthermore, the invention features simple kinematics, as, unlike the prior art, no lever chains are used in addition to the gearing in the closing drive. The use of a rolling contact in the contact area according to the invention thus reduces the number of components required for closing to a minimum, enabling a reduction in the number of components and consequently saving space and weight.

[0015] The invention is primarily intended for a soft-close function, particularly for vehicle tailgates. During the tailgate closing process, the lock holder mounted on the vehicle body moves the locking mechanism from the open position to the pre-latch position. The soft-close function, and especially the soft-close drive, then automatically moves the locking mechanism from the pre-latch position to the overtravel position and finally to the main latch position. The overtravel position ensures that the pawl engages securely into the main latch position. The rotary latch is pivoted beyond the main latch position by the soft-close drive, creating a gap between the rotary latch and the pawl, allowing the pawl to engage under spring tension into the main latch position.

[0016] When the invention refers to a lock for a motor vehicle, this means locks or locking systems used in motor vehicles. These can be locking systems for hoods, side doors, sliding doors, tailgates, covers, or other locking systems in motor vehicles, which are used wherever pivotally or slidably arranged components must be securely positioned and held during the operation of the motor vehicle. The terms "lock," "locking system," and "motor vehicle lock" are used synonymously.

[0017] The lock housing typically comprises a lock case and a lock cover, which is used to close the lock case. The lock case usually contains a locking mechanism consisting of a rotary latch and a locking pawl that interacts with it. The rotary latch, and consequently the vehicle door lock as defined above, interacts with the lock cylinder in the usual manner.

[0018] As usual, the lock housing can be mounted on the body side or on the hood / door side. In the former case, the lock housing is attached to a P24135

[0019] The vehicle body, for example, is secured by screws. The second option mentioned corresponds to the fact that the lock housing, and with it the door lock, is mounted inside or on a door, hood, flap, or the like.

[0020] The rotary latch of a motor vehicle lock typically has a forked entry slot formed by the load arm and catch arm. The lock pin of a vehicle door or hatch, such as a hood, sliding door, cover, or trunk lid, enters this slot when the door or hatch is closed. The lock pin then pivots the rotary latch from an open position to a closed position. Once the rotary latch reaches the closed position, it is locked in this position by the pawl. The lock pin can then no longer leave the entry slot of the rotary latch. In a fully closed position of the door or hatch, the latch's detent position is also called the main locking position.

[0021] The vehicle lock according to the invention is equipped with a second detent position, the so-called pre-lock position. The pre-lock position serves to catch the corresponding door or flap if it does not reach the main lock position when closing. Furthermore, the pre-lock position also serves to prevent, for example, the lock from being unintentionally opened from the main lock position. In this case, the pre-lock position acts as a safety measure to prevent the moving component from being unintentionally opened. The closing mechanism then moves the door or flap, held in the pre-lock position, into the fully closed position, i.e., the main lock position.

[0022] In an advantageous embodiment of the invention, the rolling contact between the locking lever and the rotary latch is designed as an involute geometry. This ensures that the torques are transmitted very evenly when opening and closing the lock. Furthermore, this geometry is insensitive to deviations and changes in the center distance. Automotive locks consist of housings that are essentially manufactured as injection-molded components. Highly stressed components, such as the locking mechanism and / or a locking drive, are preferably mounted in a metal lock case or a lock plate. However, at least in some areas, the components are also mounted in the plastic housing of the automotive lock. In addition to the manufacturing process, the desired service life of the locks and the required functionality also influence the tolerances in the interaction of the lock components.On the one hand, sufficient clearance must be provided in the bearings to ensure high functionality, and on the other hand, the clearance should be as small as possible to enable the most effective interaction between the components. (See P24135.)

[0023] Under certain conditions, the use of an involute geometry in the contact area between the rotary latch and the locking lever can offer a significant advantage. An involute geometry is insensitive to tolerance deviations that inevitably occur during manufacturing, assembly, and / or over the service life of the vehicle lock.

[0024] In a further advantageous embodiment, the rotary latch, actuated by the closing lever, rotates from 25 to 55 degrees, preferably from 35 to 45 degrees, and even more preferably from 40 degrees, to move from the open position to the main latch position. A small rotation angle of the rotary latch reduces the space required in the lock case, which, due to the reduced component size, also lowers material costs, for example, for the lock case itself. Furthermore, a small rotation angle, compared to a 360° rotation of the rotary latch, eliminates the need for continuous gearing in the drive area, thus also keeping the component size small and the lock costs down. This small rotation angle has also proven advantageous because the selected gear ratio allows for short actuation times for the closing drive while maintaining sufficient closing force.

[0025] In a further advantageous embodiment, a transmission ratio of 1.5 to 2.5, preferably 2, exists between the closing lever and the rotary latch. This results in optimal closing and opening functionality, as well as optimal component sizes, given the applied drive power of the closing and / or opening mechanism. A transmission ratio of 2 has proven advantageous with regard to the aforementioned parameters because it allows for a favorable drive torque. In other words, the closing force can be doubled by the transmission ratio, resulting in sufficient closing force while also enabling the use of a small electric motor.

[0026] In a further advantageous embodiment, a closing torque is established in the locking mechanism when it is in the main detent position. This means that the locking mechanism is held in the main detent position by the force and direction of action of the levers. The closing torque, unlike an opening or neutral torque, offers a decisive advantage. Vibrations during driving or other movements of the vehicle's locking mechanism could cause the locking mechanism to open unintentionally, thus endangering the occupants or other parties involved. The closing torque prevents this, as it holds the locking mechanism in the closed position.

[0027] In another advantageous embodiment, a pivotable locking element is located inside the rotary latch, which is characterized by its rotatable P24135

[0028] The bearing in the rotary latch ensures quiet or silent opening of the lock. In particular, the pivoting mounting of the detent element in the rotary latch allows for relative movement between the rotary latch and the pawl without the lock components disengaging. This relative movement reduces the load on the pawl from the rotary latch, thus providing a favorable engagement ratio between the rotary latch / detent element and the pawl. When the pawl and detent element disengage, the previously reduced force results in less noise during opening. Furthermore, the lock can be unlocked with less force, allowing the use of smaller motors.

[0029] The invention is explained in more detail below with reference to the accompanying drawings and a preferred embodiment. However, it is important to note that this embodiment does not limit the invention but merely represents an advantageous configuration. The features shown can be implemented individually or in combination with other features described in the description and claims.

[0030] In the figures, identical reference symbols denote identical or functionally equivalent components, unless otherwise stated.

[0031] They show:

[0032] Fig. 1 shows a top view of a motor vehicle lock equipped according to the invention in a pre-lock position, showing only the features essential for explaining the invention and

[0033] Fig. 2 shows the motor vehicle lock according to Fig. 1 in a main locking position,

[0034] Fig. 3 shows a top view of a motor vehicle lock equipped according to the invention in a main locking position.

[0035] Figure 1 shows a top view of a motor vehicle lock 1 in a side view of a closing drive 2 and a locking mechanism 3. In this embodiment, the closing drive 2 comprises an electric motor 9 and at least one gear stage 4, consisting of a drive pinion 11 and an output pinion 12. The drive pinion 11 is directly connected to the electric motor 9 and engages, via its teeth 10a, with the teeth 10b of the output pinion 12, which is rotatably mounted on axis A2, and drives it. The output pinion 12 is twist-locked to the closing lever 5, the closing lever 5 itself having an outwardly projecting closing pawl 6. ThisP24135

[0036] The closing pawl 6 has an involute contour 14a in its engagement area 13, which rolls on the involute contour 14b of a control block 21 during the closing process. The control block 21 is fixedly connected to the rotary latch 7, which is rotatably mounted on axis A3. Even in the pre-engagement position shown in Fig. 1, the locking pawl 8, which is rotatably mounted on axis A4, engages the rotary latch 7 and thus prevents it from moving about its axis of rotation A3 into an open position in which a lock catch 16 could move out of the lock, more precisely out of an entry area 18 of a lock housing 17.

[0037] During the closing process, the drive pinion 11 rotates about its fixed pivot point Ai in the direction of rotation Pi and thus drives the output pinion 12 in the direction of rotation P2, which moves by an angle α, preferably 40 degrees, from the pre-lock position to the main lock position. Through the engagement of the closing pawl 6 with the control block 21 connected to the rotary latch 7, the rotary latch 7 moves in the direction of P3. This causes the locking pawl 8 to move about its axis of rotation A4 in the direction of rotation P4 and engage with the rotary latch 7, locking it, as shown in Fig. 3.

[0038] Figure 2 shows the vehicle lock 1 in a main locking position. Compared to Figure 1, the closing lever 5 has already rotated further towards P2, and the rotary latch 7 has rotated accordingly towards P3. In this embodiment, preferred according to claim 12, a locking element 15 is rotatably located within the rotary latch 7. When the rotary latch 7 reaches the overtravel position during the closing process, a gap is created between the pawl 8 and the rotary latch 7, or between the pawl 8 and the locking element 15, allowing the pawl 8 to move freely along the direction of rotation P4. The rotary latch 7 is then moved from the overtravel position to the main locking position via the kinematics interacting with the closing drive 2, causing the pawl 8 to bear directly against the locking element 15.

[0039] During the opening process of the lock, the closing drive 2 moves the rotary latch 7 into the overtravel position, creating a gap between the detent element 15 and the locking pawl 8. The locking pawl 8 can now be moved completely silently in the opposite direction of rotation P4 and thus disengaged from the detent element 15. The closing lever 5 is then moved by the closing drive 2 in the opposite direction of rotation P2 and thus disengages from the rotary latch 7 via its closing pawl 6. The rotary latch 7 can now move in the opposite direction of rotation P3, thereby releasing the lock holder 16.

[0040] Figure 3 shows a variant embodiment in the main detent position, in which the pull-in pawl 6 projects further beyond the engagement area 13 with the rotary latch 7 than in the other figures. The involute geometries 14a on the P24135

[0041] The pull-down pawl 6 and 14b on the rotary latch 7 are also present here. In this embodiment, the detent element 15 is not present. Instead, the locking pawl 8 engages directly in the rotary latch 7 to secure it. Another special feature of this embodiment is the integration of the output pinion 12 and the pull-down lever 5 into a single component. It would also be conceivable to manufacture the pull-down pawl 6 together with the pull-down lever 5 and the output pinion 12 as a single component. Furthermore, this embodiment shows that the vehicle lock 1 is equipped at the end of the entry area 18 with an entry jaw buffer 19, which serves to cushion the lock holder 16 as it enters the entry area 18 of the lock 1, in order to prevent damage or wear to the lock 1 and to reduce noise during closing.Furthermore, this variant incorporates a spring lip 20 located in the entry area 18 of the lock 1. This ensures tight lateral guidance of the lock holder 16 and thus reduces movement and noise emissions of the lock holder 16.P24135.

[0042] Reference number list 1 Motor vehicle lock

[0043] 2. Pull-in drive

[0044] 3 locks

[0045] 4th gear stage

[0046] 5 pull levers

[0047] 6 Pull handle

[0048] 7 Rotary Trap

[0049] 8 locking pawl

[0050] 9 Electric motor

[0051] 10a Gearing of drive pinion

[0052] 10b Gearing of output pinion

[0053] 11 drive pinion

[0054] 12 output pinions

[0055] 13 Intervention area

[0056] 14a Involute contour pull latch

[0057] 14b involute contour rotary latch

[0058] 15 locking elements

[0059] 16 lock holders

[0060] 17 lock housings

[0061] 18 Inlet area

[0062] 19 Inlet jaw buffers

[0063] 20 spring lip

[0064] 21 Tax stone

[0065] Ai rotary axis drive pinion

[0066] A2 Rotary axis Output pinion

[0067] A3 axis of rotation, rotary trap

[0068] A4 pivot axle locking pawl

[0069] Pi direction of rotation drive pinion

[0070] P2 Direction of rotation output pinion

[0071] P3 Direction of rotation Rotary latch

[0072] P4 Rotation direction pawl

[0073] a rotation angle pull lever

Claims

P24135 Patent claims 1. Lock (1), in particular tailgate lock, for a motor vehicle comprising a locking mechanism (3) with a rotary latch (7) and at least one pawl (8), wherein the rotary latch (7) can be locked in a pre-latching position and a main latching position by means of the pawl (8), a closing drive (2) comprising an electric motor (9) and at least one gear stage with a drive pinion (11) and an output pinion (12), wherein the locking mechanism (3) can be moved from a pre-latching position to a main latching position and an overtravel position by means of the closing drive (2), characterized in that a closing pawl (6) and the rotary latch (7) have a rolling contact with each other in the engagement area (13).

2. Lock (1) according to claim 1, characterized in that the rolling contact between the pull-in pawl (6) and the rotary latch (7) is designed as an involute geometry.

3. Lock (1) according to one of claims 1 to 2, characterized in that the pull lever (5) moves the rotary latch (7) at an angle of 30 to 50 degrees, preferably at a rotation of 35 to 45 degrees from the pre-latching position to the main latching position.

4. Lock (1) according to one of claims 1 to 3, characterized in that the translation ratio between pull latch (6) and rotary latch (7) is between one and three, preferably between 1.5 and 2.

5.

5. Lock (1) according to one of claims 1 to 4, characterized in that the pull lever (5) is pivotably mounted in the motor vehicle lock (1) about an axis (A2).

6. Lock (1) according to one of claims 1 to 5, characterized in that the pull lever (5) has an extension, here referred to as a pull latch (6), which can be brought into engagement with the rotary latch (7).

7. Lock (1) according to one of claims 1 to 6, characterized in that the rotary latch (7) has an engagement contour, in particular a control stone (21), which can be brought into engagement with the pull-up latch (6).

8. Lock (1) according to claim 7, characterized in that the engagement contour (the control stone (21)) is formed from a metallic material and is connected to the metallic base body of the rotary latch (7). P24135 9. Lock (1) according to one of claims 1 to 8, characterized in that the closing drive (2) is designed as a drive spaced apart from the motor vehicle lock (1) or as a drive integrated into the lock (1).

10. Lock (1) according to one of claims 1 to 9, characterized in that a closing moment in the locking mechanism (3) is adjustable in the main locking position.

11. Lock (1) according to one of claims 1 to 10, characterized in that a pivotable locking element (15) is arranged in the rotary latch (7).

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