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 (2) that includes a rotary latch (7) which can be locked in a prelocking position and a main locking position (HR), at least one pawl (8), and a shutting and opening drive (3), by means of which the locking mechanism (2) can be moved from a prelocking position into a main locking position (HR), said movement being performed using an adjustable torque; once the main locking position (HR) has been reached, the shutting and opening drive (3) can be moved into a holding position (HP) located in front of the main locking position (HR).

Description

[0001] Description

[0002] Lock, in particular tailgate lock, for a motor vehicle

[0003] 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-locking position and a main locking position, a closing drive, wherein the locking mechanism can be transferred from a pre-locking position to a main locking position by means of the closing drive, and wherein the transfer takes place by means of a variable torque.

[0004] Today's motor vehicles are increasingly incorporating electrically assisted operating or functional elements. These electrically assisted assistance systems make it easier for the user to operate the vehicle or, for example, facilitate entry and exit. The invention relates to a motor vehicle locking device, such as those used in doors or tailgates. It is already common practice today for these locking devices to be equipped with electric drives that enable the door or tailgate to be opened and / or closed electrically.

[0005] A motor vehicle lock with an electric drive is known from DE 10 2009 020 488 A1. Such a motor vehicle lock typically has a rotary latch comprising at least one main catch. In the closed position, the rotary latch engages a striker or lock holder, which may be attached, for example, to a vehicle body. The rotary latch engages with a pawl, which secures the rotary latch in the main catch by positive locking against rotation. The motor vehicle lock further comprises an electric motor drive unit. 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 with the drive element about a rotational axis of the pawl, which can, for example, unlock the rotary latch.To secure the position of the functional elements, the document discloses friction contacts that secure the holding position of the functional elements when a drive element is switched off.

[0006] On the one hand, the end positions can be securely maintained using friction devices, for example; on the other hand, end stops are also used to decelerate the functional elements or reach a defined stop position. For example, DE 10 2013 006 521 A1 discloses the use of an electric drive to unlock a locking mechanism. The electric drive interacts with a locking lever, with the locking lever representing a fixed stop for the drive. Depending on the direction of rotation of the drive, an end position, i.e., a stop position, can be assumed.

[0007] DE 10 2013 106 672 A1 discloses a closing and opening device for a motor vehicle door lock. The closing and opening device is equipped with a drive and a transmission element. A locking mechanism is also implemented. The drive operates with the transmission element interposed on the locking mechanism to open or close it. The closing drive allows the locking mechanism to be moved from a pre-locking position to a main locking position, with the transfer taking place using a variable torque.

[0008] The locking systems or motor vehicle locks according to the invention use locking mechanisms that have a pre-locking position and a main locking position. In other words, the locking system inherently includes a locking mechanism consisting of a rotary latch and at least one pawl. When closing, for example, a tailgate, and in particular when closing a tailgate electrically, the tailgate moves into the area of ​​a lock holder, with the locking system and the lock holder interacting. Typically, when the tailgate is closed, the locking system first moves into the pre-locking position, in which the rotary latch is held by the pawl. The locking mechanism can then be moved into the main locking position by means of the closing drive. When the locking mechanism is opened, the pawl is also released from the rotary latch using the electrical drive, so that the rotary latch is released and the tailgate can be opened or opened electrically.Depending on the load acting on the locking mechanism, the release of the pawl from the rotary latch can result in a more or less loud opening noise, which is also referred to as an opening bang. Both automobile manufacturers and locking system developers strive to make the opening noise as quiet as possible, which in turn creates a quality indicator for the operator. This is where the invention comes in.

[0009] The object of the invention is to provide an improved motor vehicle lock. Furthermore, the object of the invention is to provide a motor vehicle lock in which the opening noise is as low as possible or can be completely eliminated. At the same time, the object of the invention is to provide a structurally simple and cost-effective solution for the quiet opening of a motor vehicle lock.

[0010] The problem is solved by the features of independent patent claim 1. Advantageous embodiments are specified in the subclaims. It should be noted that the exemplary embodiments described below are not limiting; rather, any possible variations of the features described in the description and the subclaims are possible.

[0011] 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 locked in a pre-locking position and a main locking position, a closing drive, wherein the locking mechanism can be transferred from a pre-locking position to a main locking position by means of the closing drive, and wherein the transfer takes place by means of a variable torque, and wherein the closing drive, after reaching the main locking position, can be transferred into a holding position located before the main locking position. By moving the closing drive into a holding position, i.e. a position located before the main locking position of the locking mechanism, the closing pawl can be used for quiet or silent opening of the locking mechanism.The closing pawl is able to interact directly with the rotary latch from the holding position and thus influence the opening process. For this purpose, the holding position is located in the immediate vicinity of, but at a distance from, an engagement point on the rotary latch. The engagement point can, for example, be a recess in the rotary latch or designed as a raised portion on the rotary latch. However, it is also conceivable that a separate bolt is attached to the rotary latch into which the closing pawl can engage. In any case, the rotary latch is able to influence the opening process by exerting a holding force on the rotary latch, which ensures easy and therefore quiet opening of the locking mechanism.

[0012] When referring to a lock for a motor vehicle, this refers to 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 pivoting or movable components must be securely positioned and held during operation of the motor vehicle. The terms "lock," "locking system," or "motor vehicle lock" are used synonymously.

[0013] The lock has a locking mechanism with a rotary latch and at least one pawl. Pawls can be used here, which interact with the rotary latch in different ways. It is conceivable that, for example, a closing or an opening moment is present in a main locking position, so that in the event of an opening moment, the pawl can be additionally secured in the main locking position with an auxiliary pawl or a blocking lever. The locking mechanism according to the invention has a pre-locking position and a main locking position. When a side door, for example, is closed for the first time, the locking mechanism, in interaction with a lock holder, moves into a pre-locking position. From this pre-locking position, the locking mechanism or the rotary latch can be moved into the main locking position by means of the closing drive. The closing drive acts directly on the rotary latch and moves the rotary latch from the pre-locking position to the main locking position.In the main locking position, the pawl rests on a main notch of the rotary latch.

[0014] An advantageous embodiment of the invention results when the holding position is arranged in a rotation angle range of a cam disc of less than 50 degrees, preferably less than 30 degrees and even more preferably less than 10 degrees, starting from the main detent position on the cam disc. The holding position is the position in which a drive for a closing pawl is arranged directly or at a short distance from the engagement element or the engagement point on the rotary latch when the locking mechanism is in the main detent position. The closing pawl is driven by means of a cam disc, whereby the cam disc itself can drive the closing pawl or a drive lever is arranged between the cam disc and the closing pawl. The drive lever or the closing pawl itself can be guided in the cam disc, whereby the holding position results in such a way that the holding position is offset by approx.50 degrees offset from the main detent position on the cam. In further design variants, and particularly when using a drive lever, the engagement point between the holding lever and cam, or between the control cam and the drive lever, can be approximately 50 degrees offset from the main detent position in the control cam. Depending on the design of the control cam on the cam, smaller angles of 30 degrees or 10 degrees can also be achieved.

[0015] As a preferred drive means, the closing drive has a cam disk, with a control contour arranged on the cam disk. The closing drive has at least one cam disk that can be driven by an electric motor. For this purpose, a gear can additionally be arranged between the electric motor and the cam disk so that sufficient force or torque can be provided. The cam disk itself has a control contour into which the closing pawl engages directly or a drive lever engages. For this purpose, the drive lever can, for example, be pivotally mounted in the motor vehicle lock so that the drive lever can generate an additional transmission ratio with respect to the closing pawl. In any case, the drive lever or the closing pawl is guided in the control contour of the cam disk so that the rotary latch can be transferred from the pre-locking position to the main locking position.The cam disc and the control contour are preferably made of plastic. The drive lever and the closing pawl, however, are preferably made of a metallic material, in particular sheet steel. The control contour allows for a targeted transmission of a variable torque to the closing pawl.

[0016] It can be advantageous and form a further embodiment of the invention if the control cam has at least one start position, one pre-locking position, one holding position, one main locking position and one over-stroke position. The control cam can thus guide the closing pawl or the drive lever throughout the entire closing process, starting from the start position, through the pre-locking position, the holding position, the main locking position and the over-stroke position. The guidance is provided entirely by the control contour, so that continuous guidance of the closing pawl can be guaranteed. Advantageously, the closing pawl or the drive lever can be guided in a continuous movement in the control cam from the start position through the pre-locking position, the holding position, the main locking position and the over-stroke position.This ensures uniform closing, whereby after reaching the over-stroke position the pawl can fall into the main locking position, whereby the pawl rests against the outer contour of the rotary latch under spring preload and automatically fits into the locking position or the main locking position.

[0017] If a pivotably mounted drive lever can be guided in the control contour, this results in an advantageous embodiment of the invention. The drive lever is mounted separately in the vehicle lock and can pivot within the vehicle lock. On one side, the drive lever engages in the control contour of the cam disc via a guide pin, for example, and on the opposite side of the bearing, the drive lever is connected to the closing pawl. By using the drive lever, a favorable transmission ratio and an optimized arrangement of the bearing of the closing pawl in the vehicle lock can be achieved. The drive lever can interact with the control contour, for example, via a stepped mandrel or via a rotatable sleeve on the drive lever. By using a sleeve, friction losses between the drive lever and the control contour can be compensated.

[0018] If the drive lever can be moved from the holding position and at least beyond the main detent position by means of the control contour, this results in a further advantage of the invention. The closing pawl is in the holding position after the closing pawl has moved the rotary latch into the main detent position. This closing process occurs when the locking mechanism is closed and the closing pawl moves the rotary latch from the pre-detent position into the main detent position. In this case, the rotary latch is advantageously moved beyond the main detent position into the over-travel position so that the pawl can engage in the main detent. The closing pawl then moves back so that the closing pawl is spaced from engagement with the rotary latch. However, the closing pawl is still in a position in which the closing pawl can engage with the engagement element of the rotary latch. The engagement element can, for example, also represent the pre-detent on the rotary latch.

[0019] Starting from this holding position, the operator can now initiate the opening process of the locking mechanism. This is done by, for example, operating a radio remote control, a control button, or an external operating lever, which activates the electric drive for the cam disc. The electric drive also serves as the closing drive. When the drive motor starts, the closing pawl is brought back into engagement with the rotary latch, and the rotary latch is moved beyond the main detent position. To open, the rotary latch is effectively released from the pawl, so that the load acting on the rotary latch is absorbed by the closing lever. The pawl can be released or moved out of the engagement area of ​​the main detent without producing an opening bang or an opening noise. This means that the locking mechanism can be opened quietly.If the rotary latch is now in the overtravel position, the pawl can be disengaged from the rotary latch, and a backward movement, i.e., a movement of the closing pawl against the closing movement, causes the rotary latch to move in the direction of the opening movement. This results in an electromechanical movement of the rotary latch in the opening direction. Only after the main catch of the rotary latch has moved past the pawl is the closing pawl disengaged from the rotary latch. The disengagement of the closing pawl and rotary latch occurs at a time when no increased load is acting on the rotary latch. A rotary latch force is generated by the sealing pressure of the door or flap acting on the rotary latch or between the rotary latch and the lock holder.The rotary latch is relieved of load by the electromechanical guide of the rotary latch over the main catch, so that when the closing pawl is released from the rotary latch, only minimal or even virtually no forces are exerted on the rotary latch. However, the forces are always so minimal that there is no longer a loud opening bang or a loud tear-off noise between the closing pawl and the rotary latch. Instead, the rotary latch is already relieved of load, allowing for easy and quiet sliding between the closing pawl and the rotary latch.

[0020] It can be advantageous if the closing lever or the closing pawl can be released from engagement with the rotary latch by means of the pawl. To move the closing pawl out of engagement with the rotary latch, the pawl can have an extension that extends into the area of ​​the closing pawl. A lifting contour interacts with the closing pawl in such a way that when the rotary latch and the closing pawl are moved, the closing pawl engages with the lifting contour and the closing pawl is moved out of the area of ​​the engagement element on the rotary latch. The closing pawl is effectively moved out of engagement with the rotary latch with the pawl. The pawl thus has a dual function. On the one hand, the pawl serves to realize the pre-lock and main detent and on the other hand, the pawl, particularly due to the design of the extension, serves to release the locking mechanism and eject the closing pawl.

[0021] If the drive lever is guided by means of the control contour via the over-stroke position into the start position, then again an advantageous further development of the invention can be achieved. If the drive lever can be moved from the holding position towards the over-stroke position when unlocking the locking mechanism, i.e. when opening the locking mechanism quietly, and can be moved directly back to the start position in the control curve, then the locking mechanism can be unlocked and the closing pawl ejected by a single, identical movement of the cam disc. In other words, if the cam disc is moved when moving the closing pawl from the holding position via the main detent position to the over-stroke position and finally to the start position by a single rotary movement and a identical rotary movement of the cam disc, then a smooth and quiet opening of the locking mechanism can be achieved.The drive lever has different positions in the control cam. In the holding position of the closing pawl, the drive lever is in a first position in the control cam and is moved by the control cam through a synchronized movement of the cam disc such that the main detent position, the overtravel position, is passed and the drive pawl is immediately moved back to the start position. The advantage of the invention lies in the fact that a uniform movement of the drive lever and, at the same time, a synchronized movement of the cam disc can relieve the load on the rotary latch, move the rotary latch back beyond the main detent position into a relieved position of the rotary latch, and finally release the closing pawl from engagement with the rotary latch.This is a key advantage of the invention, namely that a uniform and synchronized movement of the cam disc allows for a relieved opening of the locking mechanism. Independently of the uniform and synchronized movement of the cam disc, a variable torque for moving the rotary latch can be provided through the arrangement of the control cam and the bearing of the drive lever. To move the rotary latch into the over-stroke position, a high force is required or a high torque must be provided, since the rotary latch must be moved against the load of the door or flap seal. Whereas when the rotary latch is relieved in the direction of the opening movement of the rotary latch, the force decreases and thus only low forces are required to move the rotary latch or to relieve the load on the rotary latch.Through a targeted arrangement of the drive lever and the design of the control curve on the cam disc, a variable torque with high torque and, towards the end of the opening process, with high movement speed can be provided.

[0022] The cam disc not only serves to close the locking mechanism as described above, but can also be used to electrically open the locking mechanism. If immediate and rapid opening is required, the cam disc can have an additional control contour, allowing conventional opening, i.e., opening by means of an opening bang. For this purpose, the cam disc has an alternative control curve, allowing mechanical release of the pawl from the engagement area with the rotary latch. This can advantageously be achieved by moving the cam disc in the opposite direction, so that the locking mechanism can be opened.

[0023] It can be advantageous if electrical opening and closing can be carried out from the start position of the control contour on the cam disc. The control cam thus has two different directions of movement. Depending on the rotation of the cam disc, closing can be followed by quiet opening by moving the cam disc in one direction. However, if the cam disc is moved back to the start position after reaching the main detent position by a backward movement of the cam disc, so that the drive lever is in the start position in the control cam, an electrical unlocking of the locking mechanism can be carried out by an opposite movement. By means of the device according to the invention in accordance with this embodiment, both conventional opening and easy and quiet opening of the locking mechanism can be achieved.

[0024] The invention will be explained in more detail below with reference to the accompanying drawings using a preferred embodiment. However, the principle applies that the embodiment does not limit the invention, but merely represents an advantageous embodiment. The features presented can be implemented individually or in combination with other features of the description and the patent claims.

[0025] It shows:

[0026] Figure 1 is a schematic diagram of a motor vehicle lock with a locking mechanism and a closing opening drive, showing the open position of the locking mechanism, i.e., for example, an open tailgate,

[0027] Figure 2 shows a representation of the locking mechanism and the opening or closing drive after reaching the main locking position when closing the locking mechanism,

[0028] Figure 3 shows the position of the closing pawl in a holding position in the main locking position of the locking mechanism,

[0029] Figure 4 shows the overstroke position of the locking mechanism or the position of the locking mechanism in which the pawl can be opened or separated easily and quietly from the rotary latch,

[0030] Figure 5 shows a further movement of the closing or opening drive and the release of the pawl from the engagement area with the rotary latch, and

[0031] Figure 6 shows the guided opening of the rotary latch via the closing or opening drive. Figure 1 shows a motor vehicle lock 1, in particular a tailgate lock, in principle and in detail, the locking mechanism 2 and the closing and opening drive 3. The closing and opening drive 3 is specified by means of an electric motor 4, although the detailed drive of the closing and opening drive 3, in the form of, for example, a worm gear with a subsequent gear stage, is not shown. The motor vehicle lock 1 is shown in an open position, so that a lock holder 5, which is located in an inlet mouth 6 of a rotary latch 7, is released or is shown at the beginning of the closing process. A pawl 8 rests against an outer contour of the rotary latch 7 in a spring-loaded manner. The positions of the rotary latch and the closing and opening drive can be detected via the two microswitches 10, 11.In this embodiment, the closing opening drive 3 consists of a closing pawl 12, a drive lever 13 and a cam disc 14. The drive lever 13 is located with its engagement sleeve 15 in a starting position S in the control contour 16 of the cam disc 14.

[0032] If the lock holder 5 is now moved relative to the rotary latch 7, as occurs, for example, when closing a tailgate, the pawl 8 engages with the pre-lock 17 of the rotary latch 7. In this exemplary embodiment, the pre-lock 17 is attached as a raised portion on the rotary latch 7, wherein the pre-lock 17 simultaneously serves as an engagement means for the closing pawl 12. Alternatively, the pre-lock 17 can also be present as a recess in the rotary latch. After reaching the pre-lock position, the closing pawl 12 engages in the engagement means 17 and moves the rotary latch 7 in the direction of arrow P, so that the rotary latch 8 can fall into the main lock 18 on the rotary latch. At this point in time, the closing pawl 12 engages in the engagement means 17 and moves the rotary latch 7. The main lock position is shown in Figure 2. The engagement sleeve 15 of the drive lever 13 is then located within the control contour 16 in the main locking position HR.The locking mechanism 2 is now in the main detent position. The motor vehicle lock 1 is closed and the door or flap is in the locked position. Starting from the main detent position of the locking mechanism 2 and the main detent position HR of the engagement sleeve 15, the closing pawl is now moved back, but is still in a position in which the closing pawl 12 can engage with the pre-detent or the engagement means 17. The engagement sleeve 15 is now located within the control cam 16 in the holding position HP. The holding position HP is spaced from the main detent position in the cam disk 14 by an angle α of, for example, less than 50 degrees, in particular less than 30 degrees. The drive lever 13 can be pivoted fixedly in the motor vehicle 1 around the bearing point 19 during the movement.

[0033] If the operator of the motor vehicle now sends an opening command to the motor vehicle lock 1, the electric motor 4 drives the cam disc 14 further in the direction of arrow P2, so that the cam disc 14 performs a further counterclockwise rotation. This moves the rotary latch 7 into an overstroke position ÜP, so that the pawl 8 is released from the main catch 18. The pawl 8 is thus relieved, with the load on the rotary latch being absorbed by the closing pawl 12 and the closing-opening drive 3. The lock is consequently further closed, as shown in Figure 4, against the door or tailgate seal. The load on the rotary latch 7 is absorbed by the closing-opening drive 3.

[0034] Upon further movement of the cam disc 14, again in the direction of arrow P2, the pawl 8 is moved out of engagement with the rotary latch in the direction of arrow P3 by means of the extension 20 on the pawl in interaction with the closing pawl 12, so that the rotary latch 7 is released from the pawl 3. In this release position, the engagement sleeve 15 moves into a nearly linear region of the control contour 16, whereby the mechanism of the closing opening drive 3 can move the rotary latch 7 back into the opening position. The pawl 8 does not prevent the rotary latch 7 from moving in the opening direction, so that the rotary latch 7 can be returned by means of the closing opening drive 3. In other words, the opening process of the locking mechanism is already completed in the sense that no opening bang can occur between the pawl 8 and the rotary latch 7.The rotary latch 7 is then moved in the opening direction by means of the cam disc 14 and guided by the control contour 16. Only when the closing pawl 12 has reached a lifting contour 21 on the extension 20 of the locking pawl 8 does the closing pawl 12 disengage from the pre-lock 17 or the engagement means.

[0035] 17 is moved out. When the closing pawl 12 is lifted over the recessed contour 21 on the extension 20 and the cam disc 14 is moved, the drive lever 13 returns to the starting position S. Due to the inventive design of the motor vehicle lock and in particular the guidance of the drive lever 13 in the cam disc 14 or the control contour 16, the locking mechanism can be unlocked noiselessly.

[0036] List of reference symbols

[0037] 1 vehicle lock

[0038] 2 locking devices

[0039] 3 Closing opening drive

[0040] 4 electric motor

[0041] 5 lock holders

[0042] 6 Inlet mouth

[0043] 7 rotary latch

[0044] 8 pawl

[0045] 9 Contour

[0046] 10, 11 microswitch

[0047] 12 Closing latch

[0048] 13 drive levers

[0049] 14 Cam disc

[0050] 15 engagement sleeve

[0051] 16 Control contour

[0052] 17 Pre-rest, intervention means

[0053] 18 Main rest stop

[0054] 19 bearing point

[0055] 20 Extension

[0056] 21 Lifting contour

[0057] S starting position

[0058] P, P2, P3 arrow a angle

[0059] HR main rest position

[0060] HP holding position

[0061] ÜP overstroke position

[0062] FP release position

Claims

Patent claims 1. Lock (1), in particular a tailgate lock, for a motor vehicle, comprising a locking mechanism (2) with a rotary latch (7) and at least one pawl (8), wherein the rotary latch (7) can be locked in a pre-locking position and a main locking position (HR), a closing and opening drive (3), wherein the locking mechanism (2) can be transferred from a pre-locking position to a main locking position (HR) by means of the closing and opening drive (3), and wherein the transfer takes place by means of a variable torque, characterized in that the closing and opening drive (3) can be transferred into a holding position (HP) located before the main locking position (HR) has been reached.

2. Lock (1) according to claim 1, characterized in that the holding position (HP) is arranged in a rotation angle range (a) of a cam disc (14) of less than 50 degrees, preferably less than 30 degrees, and more preferably less than 10 degrees, starting from a main locking position (HR) on the cam disc (14).

3. Lock (1) according to one of claims 1 or 2, characterized in that the closing and opening drive (3) has a cam disc (14), wherein a control contour (16) is arranged on the cam disc.

4. Lock (1) according to claim 3, characterized in that the control contour (16) has at least one start position (SP), a pre-locking position, a holding position (HP), a main locking position (HR) and an over-stroke position (ÜP).

5. Lock (1) according to one of claims 3 or 4, characterized in that a pivotably mounted drive lever (13) can be guided in the control contour (16).

6. Lock (1) according to one of claims 3 to 5, characterized in that the drive lever (13) can be guided by means of the control contour (16) from the holding position (HP) and at least beyond the main locking position (HR).

7. Lock (1) according to one of claims 1 to 6, characterized in that a closing pawl (12) can be released from engagement with the rotary latch (7) by means of the locking pawl (8).

8. Lock (1) according to one of claims 3 to 7, characterized in that the drive lever (13) can be guided by means of the control contour (16) over the overstroke position (ÜP) into the start position (SP).

9. Lock (1) according to one of claims 1 to 8, characterized in that electrical opening can be carried out by means of the cam disc (14).

10. Lock (1) according to one of claims 1 to 9, characterized in that an electrical opening and closing can be carried out from the starting position (SP).

Images