Locking device

Abstract

Locking device (1) comprising a locking mechanism (2) with a rotary latch (3), a pivotable first locking pawl (4) and a second locking pawl (5) with which the pivoting of the first locking pawl (4) can be blocked, wherein the second locking pawl (5) with a blocking leg (13) abuts the first locking pawl (4) opposite the rotary latch (3) in order to block the opening rotation of the rotary latch (3) by means of the first locking pawl (4), the locking device (1) has an actuator (6) with which the second locking pawl (5) can be pivoted in a direction so that it releases and actively pivots the first locking pawl (4) successively, the first pawl (4) has a contour leg (17) and the second pawl (5) has a drive leg (16) which, when the first pawl (4) is actively pivoted by the second pawl (5), runs on the surface of the contour leg (17) of the first pawl (4), so that the pivoting movement of the first pawl (4) is actively continued by the second pawl (5).

Description

[0001] The present invention relates to a locking system with a locking mechanism, preferably electrically operated, consisting of a rotary latch and at least two locking pawls, preferably for locking and unlocking seat backrests in motor vehicles, especially folding backrests of rear seats.

[0002] It is well known that locks for motor vehicle doors with a locking mechanism consisting of a rotary latch and a locking pawl often employ locking mechanisms in which the locking pawl is supported or blocked by a (often also called a second locking pawl). The purpose of the blocking pawl is generally to increase the lock's security against unintentional opening (break-in). With other locking mechanisms featuring two locking pawls, the primary focus is on quiet opening (avoiding a loud bang when opening).

[0003] Furthermore, it is known from the field of automotive locks to use a motor, usually an electric motor, to lift the locking pawl to open the lock; this type of lock is also called a servo lock. Therefore, the vehicle user only needs to apply minimal force to the inside or outside operating lever to initiate the motor-assisted opening of the lock.

[0004] Furthermore, it is also generally known that locking systems with locks have also been proposed for use in other areas of vehicle hatches, such as tailgates, fuel filler flaps and the like.

[0005] Even though the development of locking systems for motor vehicle doors is already very advanced, especially because a number of electrical consumers and functions are integrated into the motor vehicle door, the design of locking devices for other motor vehicle flaps has so far been kept as simple as possible, so that a long service life is achieved with frequent use, especially due to the usually difficult accessibility.

[0006] US Patent 4,783,102 A describes a latch comprising a pivoting fork for receiving a strike plate, an intermediate latch that interacts with the fork to hold it in the locked position, and a main latch that interacts with the latch to hold it in position to lock the fork, these elements being biased by return springs. The main latch is provided with an arm that, at the beginning of the latch's opening sequence and in cases of poor latch maintenance, abuts the arm of the intermediate latch, forcing the latter to rotate toward releasing the fork. The presence of the arm on the main latch ensures trouble-free latch opening throughout the vehicle's lifetime, regardless of any obstruction caused by gradual loss of lubrication and dust accumulation affecting the opening.

[0007] DE 197 00 887 A1 describes a closure for a tailgate, door, or the like on a motor vehicle, with a locking element that can be moved by a motor between a locking position and an exit position. This locking element attracts a counter-locking part from a catch position into the locking position and pushes it into the exit position. For the purpose of a more advantageous application of the tailgate closure on a motor vehicle, the invention proposes providing a rotary-driven control cam acting on the locking element. The angle of rotation of this cam, from a locking position to the exit position, is smaller than the angle of rotation from the exit position to the locking position.

[0008] From DE 102 36 282 A1, a motor vehicle lock is known with a rotary latch, a first movable pawl by means of which the latch can be locked in a closed position, and a second movable pawl by means of which the first pawl can be fixed in the locked position of the latch. The second pawl comprises a support area with a first inclined surface such that the force exerted on said inclined surface by the stop of the first pawl in the locked position causes a movement of said second pawl, and with a second inclined surface such that the force exerted on said second inclined surface by the stop of the first pawl in the locked position causes a displacement of the second pawl.The lock also includes release means for relocating the second locking pawl, so that the stop of the first locking pawl in the locking position can be moved from the first inclined surface to the second inclined surface.

[0009] US 6,932,393 B2 describes a motor-operated locking and unlocking motor vehicle door lock that can be opened both mechanically and by motor, with a locking mechanism comprising several interacting elements, wherein the external actuating element, which can be operated manually from the outside door handle, can actuate a release element or directly a locking element, in particular a locking pawl, via a coupling element in the coupled position and performs a free stroke in the uncoupled position, and wherein the coupling element can be moved by motor from the coupled position to the uncoupled position and vice versa when the external actuating element is not actuated, wherein a central locking drive is provided for the motor actuation of the coupling element and the central locking drive can also actuate the release element or the locking element in a second function.This is characterized by the fact that, normally, the opening actuation is carried out mechanically only with the outer actuating element, and that in the second function, the central locking drive actuates the unlocking element or the locking element only when the outer actuating element is already in its idle stroke during this phase.

[0010] From DE 10 2007 045 228 A1 a vehicle door lock is known in which, when a vehicle door is closed, a rotary latch engages in a locking bolt, wherein the rotary latch can be locked by a locking device in the closed state of the vehicle door and is supported on the locking bolt.

[0011] Starting from this premise, the object of the present invention is to at least partially solve the problems described with reference to the prior art. In particular, a simple locking device is to be provided that is suitable for use in locking backrests in motor vehicles. The ease of use and the noise level during operation of the locking device are to be improved in particular.

[0012] These problems are solved with a locking device according to the features of claim 1. Advantageous further developments of the locking device are specified in the dependent claims. It should be noted that the features listed individually in the claims can be combined with one another in any technologically meaningful way and demonstrate further embodiments of the invention. The description, particularly in conjunction with the figures, further explains the invention and provides additional exemplary embodiments.

[0013] The device according to the invention comprises at least one locking mechanism with a rotary latch, a pivotable first locking pawl, and a second locking pawl with which the pivoting of the first locking pawl can be blocked. The locking device further has an actuator that pivots the second locking pawl in a direction such that it successively releases and actively pivots the first locking pawl.

[0014] The primary objective is to ensure that the two locking pawls are each engaged in a targeted manner for safe and quiet lifting from the rotary latch.

[0015] The locking mechanism is preferably designed with at least three parts. The rotary latch is spring-loaded and rotatable about a pivot axis, and has an opening in which the rotary latch can receive a retaining bolt. By pivoting the rotary latch, the position of the retaining bolt is fixed in the locking device. To prevent the rotary latch from pivoting back to the open position, it is locked in place by the first pawl. For this purpose, the first pawl is mounted about a different pivot point and bears against the circumference of the rotary latch. This exerts a force on the rotary latch that prevents rotation into the open position.The contact between the first pawl and the rotary latch is preferably configured such that the force does not pass through the pivot point of the first pawl, but rather a moment is provided with which the rotary latch pushes the first pawl away towards the open position during spring-loaded rotation. To nevertheless ensure secure locking of the rotary latch, the first pawl is blocked by a second pawl. This second pawl is also rotatably mounted, with the pivot points of the rotary latch, first pawl, and second pawl essentially forming a triangle, and the first pawl extending into and being locked within a line connecting the pivot points of the rotary latch and the second pawl.

[0016] The actuator can be initiated manually and / or electrically. For example, the actuator can act on the second pawl via a linkage, Bowden cables, and an actuating element (button, sensor, handle). However, it is preferred to use a motor-driven actuator. This motor-driven actuator is connected, for example, to a controller that activates an electric motor as needed, which then acts on the second pawl, possibly via a gearbox. This means, in particular, that the actuator's movement acts directly on the second pawl; therefore, no pivoting levers are provided between the actuator and the pawl.

[0017] The actuator is connected to the second pawl in such a way that the pawl is pivoted in (only) one direction during the opening process of the locking device, whereby the contact to the first pawl is initially released, so that the first pawl can then be moved, or is moved, at least temporarily independently of the movement of the second pawl, and the second pawl subsequently interacts with the first pawl again when the pivoting movement continues in the same direction, so that the second pawl actively continues to pivot the first pawl in its opening direction.The term "active" here means that, in this subsequent time period, the first pawl is preferably pivoted solely by the second pawl. It is particularly preferred that the second pawl moves in a controlled manner on the first pawl, thus allowing the pivot paths during contact between the two pawls to be determined and predetermined. Furthermore, it is considered advantageous that the second pawl securely fixes the first pawl in the open position.

[0018] The proposed solution ensures, in particular, that the rotary latch and the first locking pawl are separated quietly and that the first locking pawl assumes a defined position during the opening process. This results in reliable operation of the locking device as well as a simple and compact design. It can also withstand high closing forces, for example, in the event of particularly high loads on the backrest of a seat equipped with such a locking device due to sudden deceleration of the vehicle.

[0019] According to a further development of the locking device, the actuator is designed with an electric motor, an output shaft, and a drive wheel that interacts with the output shaft. The electric motor is connected to a suitable control system and power supply so that it can be activated as needed. The torque generated in the electric motor is transmitted via an output shaft, for example, a worm gear, to an output wheel, for example, one with external teeth. The output wheel, which is rotatably mounted, has means that interact with the second pawl and set it into the desired movement. Preferably, the output shaft and the drive wheel are made of plastic and / or noise-dampening materials.

[0020] Furthermore, it is proposed here that the drive wheel has a cam guide for a drive pin of the second pawl. Advantageously, the drive wheel is arranged in the locking device such that it at least partially covers the position of the second pawl. The cam guide is formed on the side facing the second pawl. The cam guide is specifically designed as a recess in the drive wheel and is configured such that a drive pin of the second pawl projects into this recess and bears laterally against the cam guide. The cam guide has a closed path, but one that deviates from a circular path, so that, in particular, the distance of the cam guide from the axis of rotation of the drive wheel varies during one revolution of the drive wheel.As the drive wheel rotates, the drive pin engages the cam guide with friction, thus generating a controlled stroke from the circumference of the drive wheel towards the axis of rotation. The cam guide's path allows direct control over the pivoting speed and / or the pivoting travel of the second pawl.

[0021] According to further training, it is also suggested that the actuator be unidirectional. In other words, this means, in particular, that the actuator always moves in only one direction, thus eliminating the need for a return movement. If an electric motor is used for the actuator, this means, specifically, that the electric motor is always driven or moved in only one direction of rotation. The electric motor is activated during the opening process and stopped after the opening process is complete. This exact starting position can then be used for the next opening process. This has the particular advantage of preventing noise generation when the actuator returns to its original position.

[0022] Furthermore, it is considered advantageous that the second pawl, in addition to the blocking arm for the first pawl, has a stop arm for a pivot limiter and a drive arm for the second pawl. Preferably, the second pawl has a metallic base body and at least the blocking arm also has a metallic surface in the contact area with the first pawl. It is also preferred to provide damping material for the stop arm so that the contact of this arm with the pivot limiter is as quiet as possible. It is also preferred that the stop arm and the drive arm are located essentially opposite the pivot point of the second pawl, while the blocking arm is arranged between them on the side facing the first pawl.The pivot limiter can, for example, be permanently attached to the housing of such a locking device and may also serve to hold a return spring, for example for the second locking pawl.

[0023] In a further embodiment, where the second pawl has a drive leg for the second pawl, the drive leg is made of a damping material. It is particularly preferred that the first pawl, in the section where it interacts during the active opening process, is also made of a damping material. Suitable damping materials include, in particular, plastic overmolding, elastic materials, coatings, and the like. Due to the frictional contact, it must be ensured that the damping material is abrasion-resistant. The two pawls are typically made of a metallic base body, for example, a stamped component. To minimize noise generation, this contact between the two pawls (but not for the locking contact) is made with the damping materials.

[0024] Furthermore, it can be advantageous for the locking mechanism to be arranged in a first plane and the actuator in a second plane, with the components of adjacent planes interacting by means of at least one drive pin. Such a compact design of the locking device allows, for example, its integration into a single housing or a common housing cover. Starting from a housing base plate, the locking mechanism is initially arranged in the first plane. The locking mechanism comprises the rotary latch and the two pawls. The actuator is located one plane above, in the second plane. The actuator thus at least partially covers the locking mechanism in the first plane. The actuator has one or more drive pins that extend downwards into the first plane and, in particular, contact the second pawl, or vice versa.Naturally, the second pawl can also have multiple drive pins. It is also possible that the actuator's drive wheel has a drive pin that interacts with a circumferential edge of the second pawl.

[0025] Furthermore, the second pawl can be designed with a return spring. This return spring can, for example, ensure a secure frictional engagement with the cam guide of the drive wheel. It is also possible that the second pawl, which is guided by the cam guide during the opening process, springs back to a desired starting position at the end of the opening process due to the spring tension, thereby making contact with the cam guide again (at a different location).

[0026] Finally, it is also considered advantageous that the rotary latch has a projection and the first pawl has a recess suitable for receiving the projection. Usually, the rotary latch is designed with a detent that serves (on one side) to engage the first pawl. Here, however, it is proposed that a kind of (two-sided) enclosure of the rotary latch's projection (with some play) be achieved. For this purpose, the pawl is designed with a relatively large recess, the recess being formed in particular by a U-shaped section of the first pawl. This ensures a particularly secure retention of the rotary latch in the first pawl, so that, in particular, the movement of the rotary latch in both directions of rotation is blocked by the first pawl.

[0027] The invention is particularly applicable in a motor vehicle comprising a seat with a folding backrest, wherein the backrest can be locked in a position by a locking device according to one of the embodiments presented here. The seat is particularly a rear seat whose backrest can be folded down to allow access to the trunk or rear area. For this purpose, the locking device can be attached to the backrest itself, the seat, or a mounting component of the vehicle body and interact with a retaining bolt attached to another of the aforementioned components.

[0028] The invention and its technical context are explained in more detail below with reference to the figures. It should be noted that the figures show preferred embodiments of the invention, but that the invention is not limited to these. They schematically depict: Fig. 1: an embodiment of the locking device according to the invention, Fig. 2: a variant design of a drive wheel for an actuator, Fig. 3: a view of the locking device Fig. 1 without the actuator in locked position, Fig. 4: the locking device Fig. 3, wherein the second pawl releases the first pawl, Fig. 5: the locking device Fig. 4, where the second pawl now actively pivots the first pawl, Fig. 6: a position of the locking device between the in the Fig. 4 and Fig. 5 positions shown and Fig. 7: a motor vehicle with a folding seat.

[0029] Fig. Figure 1 shows a locking device 1, wherein a locking mechanism 2 is implemented, consisting of a rotary latch 3 and two pivotable pawls 4, 5, namely the first pawl 4 and the second pawl 5. In the embodiment illustrated here, these three locking mechanism components are rotatably mounted on a base plate of the housing 27 in a common, first plane 36. A top view of such a locking device 1 is shown, with the housing cover omitted. A recess 25 is visible on the left side of the housing 27, into which a retaining bolt 26 can enter. In the locked position, the retaining bolt 26 is enclosed by the rotatably mounted rotary latch 3, so that it can no longer leave the recess 25. The rotary latch 3 is pre-tensioned by the spring element 12 and therefore tends to pivot back (here clockwise) to the open position.Furthermore, it should be taken into account that seat cushions, seals and the like usually exist between the locking device and the component to be locked, so that the retaining bolt 26 also exerts a restoring force on the rotary latch 3.

[0030] Above the locking mechanism 2, i.e., in a second level 37, a motor-driven actuator 6 is arranged. The actuator 6 comprises an electric motor 8, which is preferably operated unidirectionally in only one direction of rotation 18. On the output side, the electric motor 8 is designed with an output shaft 9, for example, in the form of a worm gear. This output shaft 9 then acts on a drive gear 10, which may optionally have external teeth.

[0031] The drive wheel 10 directly drives or moves the second pawl 5, which is partially obscured by the drive wheel 10. For this purpose, a drive pin 20 is formed between the drive wheel 10 and the second pawl 5. The movement of the second pawl 5 is controlled via this drive pin 20, as will be explained in detail with reference to the following figures.

[0032] Fig. Figure 2 shows a possible embodiment of a drive wheel 10, which interacts with the drive pin 20 of the second pawl (not shown here). The drive wheel 10 shown has a toothed ring 33 on its outer circumference, via which the motor torque is transmitted to the drive wheel 10, causing the drive wheel 10 to rotate about an axis of rotation 34, for example in the indicated direction of rotation 18. On the side of the drive wheel 10 facing the drive pin 20, a slot- or groove-like recess 35 is formed – the width of which is preferably significantly larger than the diameter of the drive pin 20. It is also possible for the inner and / or outer rim to serve (partially or temporarily) as a cam guide 7 for the drive pin 20.When the drive wheel 10 is moved in the direction of rotation 18, the outer cam guide 7 passes under the drive pin 20, and due to the path of the outer cam guide 7, the drive pin 20 is moved further towards the axis of rotation 34. To achieve this, the outer cam guide 7 moves towards the axis of rotation 34 in the opposite direction to the direction of rotation 18. In this way, a controlled stroke 32 for the drive pin 20 in the direction of rotation 18 of the drive wheel 10 can be achieved. The path can be designed such that the drive pin 20 is repositioned in the desired starting position at the end or beginning of the opening process without requiring any return movements.

[0033] Fig. Figure 3 essentially shows the locking device again according to Fig. Figure 1, where the actuator 6 is not shown. In particular, it can be seen again that the rotary latch 3 has a projection 21 that engages in a U-shaped recess 22 of the first pawl 4. To block the opening rotation of the rotary latch 3 or the first pawl 4, the second pawl 5 rests against the first pawl 4 with a blocking leg 13 opposite the rotary latch 3. This secures the position of the rotary latch 3 or the first pawl 4.

[0034] The second pawl 5 now has two further legs. The stop leg 14, which here rests against a pivot limiter 15, defines the exact position of the blocking leg 13 relative to the first pawl 4. As can be seen here, the stop leg 14 has a damping material 19 on its outer surface to ensure a quiet stop against the pivot limiter 15. Opposite the stop leg 14 is a drive leg 16, which is also partially encased in a damping material. This drive leg 16 interacts—as will be explained later—with the second pawl 4. A drive pin 20 for the drive wheel located above it is formed on the drive leg 16.

[0035] Fig. Figure 4 illustrates the situation in which the rotary latch 3 is released. For this, the second pawl 5 is moved by the actuator 6 in the indicated direction of rotation (white arrow), whereby the blocking arm 13 of the second pawl 5 is moved away from the first pawl 4. This allows the restoring torque of the rotary latch 3 to act and thus initiate the opening movement of the first pawl 4.

[0036] With this restoring torque, the first pawl 4 is pivoted by a certain amount, whereby this amount may vary, since the restoring torques generated by the retaining bolt 26 must also be taken into account. Fig. Figure 5 now shows the phase of the opening process in which the second pawl 5 actively pivots the first pawl 4 into the desired open position. For this to occur, the second pawl 5 is still being moved by the actuator 6, so that the drive arm 16 of the second pawl 5 comes into contact with a contour arm 17 of the first pawl 4. As the second pawl 5 pivots, the drive arm 16 runs along the surface of the contour arm 17 of the first pawl 4, so that the pivoting movement of the first pawl 4 is actively continued by the second pawl 5. To minimize the noise of this frictional contact between the contour arm 17 and the drive arm 16, a damping material 19 is provided on the contour arm 17 (and the drive arm 16).

[0037] Particularly when relatively high restoring torques are exerted by the rotary latch 3 on the first pawl 4, the second pawl 5 initially performs an idle rotation before its drive arm 16 engages the contour arm 17. This situation is described in Fig. Figure 6 illustrates this. In this phase, the processes a) releasing the first pawl 4 and b) actively moving the first pawl 4 are separated or spaced apart in time.

[0038] As already mentioned, the locking device is primarily used as a locking system for locking and unlocking seat backrests in motor vehicles, especially folding backrests in rear seats. This is now in Fig.Figure 7 illustrates this. A motor vehicle 23 with a seat 29 is shown schematically. The backrest 24 of the seat 29 is pivotable or foldable (dashed position), thus enabling, for example, access to a storage compartment 31. To ensure that this only occurs at desired times, the backrest 24 is fixed to one (or more) fastening component(s) 30, for example, a component of the vehicle body 23, by means of the locking device 1 described herein according to the invention. The retaining bolt, as well as the locking device, can be arranged either on the backrest 24 or on the fastening component 30. It is also possible to provide several such locking devices 1 for one seat 29.

Claims

[1] Locking device (1) comprising a locking mechanism (2) with a rotary latch (3), a pivotable first locking pawl (4) and a second locking pawl (5) with which the pivoting of the first locking pawl (4) can be blocked, wherein the second locking pawl (5) with a blocking leg (13) abuts the first locking pawl (4) opposite the rotary latch (3) in order to block the opening rotation of the rotary latch (3) by means of the first locking pawl (4), the locking device (1) has an actuator (6) with which the second locking pawl (5) can be pivoted in a direction so that it releases and actively pivots the first locking pawl (4) successively, the first pawl (4) has a contour leg (17) and the second pawl (5) has a drive leg (16) which, when the first pawl (4) is actively pivoted by the second pawl (5), runs on the surface of the contour leg (17) of the first pawl (4), so that the pivoting movement of the first pawl (4) is actively continued by the second pawl (5). [2] Locking device (1) according to claim 1, in which the actuator (6) is designed with an electric motor (8) with an output shaft (9) and a drive wheel (10) cooperating with the output shaft (9). [3] Locking device (1) according to claim 2, wherein the drive wheel (10) has a cam guide (7) for a drive pin (20) of the second locking pawl (5). [4] Locking device (1) according to one of the preceding claims, wherein the actuator (6) is unidirectional. [5] Locking device (1) according to one of the preceding claims, wherein the second locking pawl (5) has a stop leg (14) for a pivot limiter (15). [6] Locking device (1) according to one of the preceding claims, wherein the drive leg (16) is equipped with a damping material (19). [7] Locking device (1) according to one of the preceding claims, wherein the locking mechanism (2) is arranged in a first plane (36) and the actuator (6) is arranged in a second plane (37), wherein the components of adjacent planes interact by means of at least one drive pin (20). [8] Locking device (1) according to one of the preceding claims, wherein the second locking pawl (5) is equipped with a return spring. [9] Locking device (1) according to one of the preceding claims, wherein the rotary latch (3) has a projection (21) and the first locking pawl (4) has a recess (22) suitable for receiving the projection (21). [10] Motor vehicle (23) comprising a seat with a foldable backrest (24), wherein the backrest (24) can be locked in a position by means of a locking device (1) according to one of the preceding claims.

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