Parking lock mechanism for a motor vehicle

Abstract

The invention relates to a parking lock mechanism for a motor vehicle, the motor vehicle having a drive shaft (1) which is provided for the mechanical transmission of power to at least one drive wheel and which has at least one locking region (2) and is provided with a parking pawl (3) for the selective formation of a form-fit connection with the locking region (2), the parking lock mechanism having a locking mode in which the parking pawl (3) is moved into a locking position and forms a form-fit connection with the locking region (2) there, and a driving mode in which the parking pawl (3) is moved into a driving position in which the parking pawl does not form a connection with the locking region (2), the parking pawl (3) being pivotable about a pawl axis (4) from the locking position into the driving position and being provided with a pawl spring device (5) which pre-tensions the parking pawl (3) into the driving position and with a pawl operating device which has a pawl actuator (6) with a pawl actuator shaft (7) and has a pawl cone (8), the pawl cone (8) being movable along a cone axis (9) by means of the pawl actuator (6), the cone axis (9) being oriented parallel to the pawl axis, and the pawl cone being movable along the cone axis (9) between a cone driving position and a cone locking position, and the parking pawl (3) being pressed into the locking position against the pre-tension of the pawl spring device (5) by the pawl cone (8) in the cone locking position, and in order to move the pawl cone (8) along the cone axis (9) there being provided a locking cone lever (10) which is freely rotatable by means of the pawl actuator shaft (7).

Description

TECHNICAL FIELD

[0001] The invention relates to a parking lock mechanism in a motor vehicle, in particular in an electrically operated vehicle. BACKGROUND

[0002] In this context, a parking lock mechanism is understood to be a mechanism for positively locking a drive shaft, which is permanently coupled to at least one drive wheel of the motor vehicle or to a drive axle at least in the state in which the drive shaft is locked. Parking lock mechanisms are known per se from the prior art, in particular from automatic transmissions. In such transmissions, in particular when a parking mode, the so-called "P" mode, is selected for the automatic transmission (P N R D), the output shaft in the automatic transmission can usually be positively coupled to the transmission housing.

[0003] From DE 102 015 211 367 A1, an automatic transmission of a vehicle with a central synchronizing device and a method for operating an automatic transmission are known, in which a parking lock function with a self-locking assembly can be implemented. SUMMARY

[0004] The implementation of a parking lock function usually requires mechanically complex mechanisms. It is the task of the invention to present a simple parking lock mechanism.

[0005] In the sense of the invention, a parking lock mechanism for a motor vehicle is understood to be a device for positively locking a drive shaft, which is provided for mechanically transmitting power to at least one drive wheel of the motor vehicle. Preferably, this drive shaft is selectively or preferably permanently connected to said at least one drive wheel in a torque-conveying manner. In particular with this design, the drive wheel is positively locked by means of the parking lock mechanism as soon as the parking lock is engaged.

[0006] Furthermore, the drive shaft to be locked has a locking region, which is preferably configured as a locking wheel (Sperrenrad), which is oriented concentrically to the drive shaft and which is further preferably connected non-rotatably to the drive shaft or is preferably configured in one piece with the drive shaft. Furthermore, the locking region is configured in such a way that at least one parking pawl selectively engages in the locking region to form a positive connection. Functionally, when the parking pawl engages in the locking region of the drive shaft, the drive shaft and thus said at least one drive wheel is locked. In other words, the parking lock mechanism thus has at least two modes, wherein a first mode can be seen as "parking lock engaged", the so-called locking mode, and another mode can be seen as "parking lock disengaged", the so-called running mode, in which the drive wheel is positively locked in the first mode and in which this is not the case in the second mode, instead, in the second mode the drive shaft is rotatable and said at least one drive wheel can be driven by the drive shaft.

[0007] Furthermore, the parking pawl is movable by means of the parking lock mechanism at least between two positions. In a locked mode, the parking pawl is moved into a locked position and forms in this position a form-locking connection with the locking region for locking the drive shaft. Furthermore, the parking lock mechanism has a driving mode in which the parking pawl is moved into a driving position in which the parking pawl does not form a form-locking connection with the locking region, in particular the drive shaft is rotatable in this mode for driving the motor vehicle.

[0008] Furthermore, the parking pawl is pivotable about a pawl axis in order to assume the locked position or the driving position. The parking lock mechanism has a pawl spring device which pre-tensions the parking pawl into the driving position. In particular in an unoperated state, the pawl spring device holds the parking pawl in the driving position. In order to change the position of the parking pawl, the parking lock mechanism has a pawl operating device which has a pawl actuator with a pawl actuator shaft and which has a pawl cone. The pawl cone is provided here for preferably indirectly or preferably directly applying an operating force to the parking pawl, in the case of which operating force the parking pawl is moved from the driving position into the locked position. In particular in order to provide the operating force applied to the parking pawl, the pawl cone is movable or movable by means of the pawl actuator along a cone axis. Further preferably, the pawl cone has at least sectionally a conical profile about the cone axis and further preferably the pawl cone is in contact with the parking pawl, in particular in order to move the parking pawl from the driving position into the locked position.

[0009] The cone axis is oriented parallel to the pawl axis and thus the parking pawl is pivotable about the pawl axis, in particular by the profile of the pawl cone together with the movement of the pawl cone along the cone axis. The pawl cone is movable along the cone axis into at least two positions, one of which positions can be understood as a so-called cone locked position and the other position can be understood as a cone driving position. Furthermore, the parking pawl is moved into the locked position when the parking pawl is contacted by the pawl cone and the pawl cone is in the cone locked position or the parking pawl is pressed into the locked position by the pawl cone against the spring force of the pawl spring device in this case. If the pawl cone is in the cone driving position, the parking pawl is pressed into the driving position by the pawl spring device and the locking region of the drive shaft is rotatable relative to the pawl.

[0010] In order to move the pawl cone along the cone axis, a blocking cone lever (Sperrkonushebel) is provided, which is coupled indirectly or directly with the pawl cone and which can also be rotated or pivoted by means of the pawl actuator shaft of the pawl actuator. The blocking cone lever can here be freely rotatable by the pawl actuator shaft. In the sense of the invention, a "freely rotatable blocking cone lever" is to be understood as meaning that, on the blocking cone lever, in particular when the pawl cone is displaced between the cone blocking position and the cone driving position, only the force exerted by the pawl cone, as well as unavoidable bearing forces and inertial forces, act on the blocking cone lever. Further preferably, "freely rotatable" means that the pawl lever can be rotated freely at least between two end points, in particular without the pawl lever having to be able to perform a complete rotation (360° and more), whereby the pawl lever is to be understood in the sense of the invention as being freely rotatable. In particular, no additional forces act on the freely movable or freely rotatable blocking cone lever, such as additional forces which can occur, for example, in the case of a latching of the blocking cone lever.

[0011] Such a latching can be provided, in particular, in order to prefer a certain geometric position of the blocking cone lever. Such a preference can be provided in order to reduce a "play" in the parking lock mechanism or to predetermine a certain mechanical position of the mechanism in the event of a failure of the pawl actuator. In contrast thereto, a freely rotatable blocking cone lever offers the advantage that the parking lock mechanism is simple in structure and enables a uniform and precise actuation of the pawl cone, since the pawl cone can be moved along the cone axis uniformly and without a mechanical preference, and thus uniformly. Furthermore, the parking lock mechanism can be easily detected, since there is a simpler relationship between the movement of the pawl cone and the applied actuation force than in the case of a blocking cone lever on which also forces which are not introduced by the pawl cone (latching) act, and in particular, as a result of this, an improved failure monitoring of the proposed parking lock mechanism can be achieved.

[0012] In a preferred embodiment, a decoupling spring device with a decoupling spring is arranged between the pawl actuator shaft and the pawl cone, in terms of force transmission between them. In particular, the decoupling spring device decouples the pawl actuator shaft from the pawl cone in at least one force transmission direction. To put it in words, in the operation of the parking lock mechanism, the pawl actuator shaft indirectly or directly outputs an operating force to the decoupling spring device, and the decoupling spring device outputs the operating force to the pawl cone. In the case where the pawl cone cannot move, in particular because the parking pawl cannot or has not yet been engaged into the locking region, the operating force of the pawl actuator shaft first pre-tensions the decoupling spring of the decoupling spring device, without the pawl cone having to move, but the pawl cone applies the operating force to the parking pawl. If the parking pawl can engage into the locking region at another point in time on the basis of changing geometric conditions and thus establish a positive connection between the parking pawl and the locking region, the pawl cone moves under the operating force from the decoupling spring device into the cone locking position and here rotates the parking pawl into the locking position. In particular with such a decoupling spring device, on the one hand the parking pawl can be reliably engaged into the locking region and on the other hand the pawl actuator shaft can be decoupled from force impacts, as can occur when the parking pawl collides with the locking region and has not yet established a positive connection therewith.

[0013] In a preferred embodiment of the parking lock mechanism with a decoupling spring device, the decoupling spring is arranged between the pawl actuator shaft and the locking cone lever in the force transmission direction from the pawl actuator shaft to the locking cone lever. Further preferably, the decoupling spring is configured as a torsion spring or a spiral spring, and further preferably such a decoupling spring is pre-tensioned by a rotation of the pawl actuator shaft relative to the locking cone lever and can be understood as an actuator decoupling spring. Further preferably, the force transmission from the pawl actuator shaft to the locking cone lever takes place at least temporarily or preferably permanently and at least substantially by means of the decoupling spring during the planned operation. Preferably, the locking cone lever is rotatably supported on the pawl actuator shaft and mechanically coupled with the pawl actuator shaft by means of the decoupling spring for the transmission of the operating force, in other words the operating force can thus be transmitted from the pawl actuator shaft to the locking cone lever by means of the decoupling spring. In particular, the rotatably supported and coupled locking cone lever with the decoupling spring is a particularly space-saving arrangement for providing a decoupling function between the pawl actuator shaft and the pawl cone as an operating element for the parking pawl.

[0014] In a preferred embodiment, the decoupling spring or preferably a further decoupling spring is arranged between the blocking cone lever and the pawl cone in the direction of force transmission from the blocking cone lever onto the pawl cone. Preferably, this decoupling spring or further decoupling spring, which is indirectly or directly arranged between the blocking cone lever and the pawl cone, is configured as a coil spring or as a combination of a plurality of disc springs and can be understood as a lever decoupling spring. Further preferably, this decoupling spring is pre-tensioned by the movement of the blocking cone lever (driven by the pawl actuator shaft) relative to the pawl cone, in particular when the pawl cone is blocked in its movement along the cone axis. Further preferably, the force transmission from the blocking cone lever onto the pawl cone takes place at least temporarily or preferably permanently, at least substantially by means of this decoupling spring during the planned operation. Preferably, the blocking cone lever is received non-rotatably on the pawl actuator shaft and is indirectly or directly mechanically coupled to the pawl cone by means of the decoupling spring for the transmission of the operating force onto the pawl cone. In other words, the operating force can thus be transmitted from the blocking cone lever onto the pawl cone by means of the decoupling spring. This decoupling spring and thus the elastic coupling of the blocking cone lever and the pawl cone is in particular a particularly simple and operationally reliable arrangement for providing a decoupling function.

[0015] In a preferred embodiment, the pawl cone is movably supported on the pawl spindle along the cone axis, the pawl cone being pressed into an end position on the pawl spindle by the lever decoupling spring. Preferably, the lever decoupling spring is configured as a pressure spring. Further preferably, the lever decoupling spring is thus indirectly arranged between the blocking cone lever and the pawl cone. In particular, this arrangement enables a particularly simple installation, since the pawl spindle together with the pawl cone and the lever decoupling spring mounted thereon can be installed as an assembly and a particularly simple installation of this assembly on the blocking cone lever is possible.

[0016] In a preferred embodiment, the pawl actuator is configured as a self-locking actuator. In the sense of the present application, a "self-locking actuator" can in particular be understood as an actuator which maintains the position of the pawl actuator shaft without external loading in terms of power, in particular current and voltage, even if operating forces, in particular via the blocking cone lever, act on the pawl actuator shaft. In particular, by means of this feature of the present application a simple construction of the parking lock mechanism is possible, since no additional, in particular mechanical, locking is required to maintain a specific position of the pawl actuator shaft.

[0017] In a preferred embodiment of the application, the pawl actuator has a pawl sensor for determining the position of the pawl actuator shaft. Further preferably, the pawl sensor is configured as a rotational angle sensor. In particular, the position of the pawl actuator shaft can be detected by means of the pawl sensor and the function of the pawl actuator can thus be monitored. BRIEF DESCRIPTION OF DRAWINGS

[0018] The individual features of the application and their preferred embodiments are explained in detail below with the aid of the drawings, in which other feature combinations than those shown are also possible in principle. In the drawings:

[0019] Figure 1 A perspective, partially sectioned view of a parking lock mechanism is shown.

[0020] Figure 2 A top view of a parking lock mechanism is shown. DETAILED DESCRIPTION

[0021] In Figure 1 A perspective, partially sectioned view of a parking lock mechanism is shown, in which the drive shaft to be locked or positively locked by means of the mechanism is not shown in the figure.

[0022] The pawl actuator 6 is a rotational actuator which has a pawl actuator shaft 7 for outputting an operating force to the pawl cone 8. The pawl actuator 6 is configured as a self- locking actuator, which is understood to mean that the position of the pawl actuator shaft 7 is maintained without an energy supply, in particular an electrical current, voltage, from outside the pawl actuator 6, even if a force, in particular by the pawl cone 8, is applied to the locking cone lever 10, when the pawl actuator 6 is switched off. The self-locking in the pawl actuator 6 can be achieved, in particular, by the friction conditions in the pawl actuator 6.

[0023] Furthermore, the pawl actuator 6 has a pawl sensor 13 by means of which the position of the pawl actuator shaft 7 can be detected and the operating state of the parking lock mechanism can thus be monitored. The pawl actuator 6 is shown in a cutaway state. The locking cone lever 10 is arranged non-rotatably on the pawl actuator shaft 7 and can be pivoted in the pawl lever direction 19 by means of the pawl actuator shaft. A rotational movement of the pawl actuator shaft 7 thus results in a movement of the locking cone lever 10. The pawl spindle 12 is kinematically coupled to the locking cone lever 10. The pawl cone 8 is arranged on the pawl spindle 12, which has at least sectionally a conical outer contour 14, the cone axis 9 forming the axis of symmetry for the conical section 14.

[0024] The pawl tapered portion 8 is movably supported on the pawl spindle 12 along the tapered portion axis 9, i.e., along the tapered portion movement direction 18, and in the illustrated embodiment is pre-tensioned downward to a position by means of a lever decoupling spring 11 designed as a pressure spring. Therefore, if the pawl spindle 12 moves along the tapered portion movement direction 18 via the locking tapered portion lever 10, and no or only a small force acts from the parking pawl 3 on the pawl tapered portion 8, the pawl tapered portion moves together with the pawl spindle 12. However, if the parking pawl cannot engage directly, especially because it cannot be inserted into the locking region 2, particularly due to the rotational position of the locking region 2, the locking tapered portion lever 10 will hold the pawl spindle 12 in... Figure 1 The pawl cone 8 is pushed downwards in the indicated direction, and initially (despite the movement of the locking cone lever 10) remains in its position and the lever decoupling spring 11 is tensioned. If the locking region 2 is subsequently positioned relative to the pawl 3 such that the pawl can engage in the locking region 2 to form a form-locking connection, the lever decoupling spring 11 pushes the pawl cone 8 downwards (see [link]). Figure 1 (as shown in the orientation) and pivot the parking pawl 3 to the locked position shown.

[0025] exist Figure 1 In the diagram, the pawl cone 8 is in its cone-shaped locked position, and the parking pawl 3 rests against the cylindrical section 15 of the pawl cone 8, thereby overcoming the pawl spring device 5 (see Figure 1). Figure 2 The spring is preloaded and pivoted into its locked position. To move the parking pawl 3, the pawl cone 8 rests on the support plate 16.

[0026] exist Figure 2 The parking pawl 3 is shown in the engaged state (locked position), meaning that the parking pawl 3 is form-locked with the locking region 2 of the drive shaft 1, and the drive shaft 1 is locked or cannot rotate. The parking pawl 3 can move about the pawl axis 4 in the pivot direction 17, which is arranged parallel to and radially spaced from the axis of the tapered portion 8. The parking pawl 3 is preloaded into the driving position (not shown) by means of the pawl spring device 5. The tapered portion 8 of the pawl moves along the axis of the tapered portion 8 to insert the parking pawl 3 and support it on the support plate 16, so as to apply an operating force against the spring preload of the pawl spring device 5.

[0027] In other words, the described parking lock mechanism functions without an additional detent, since the locking cone lever 10 can be freely rotated. The detent enables a defined position state to be supported and ensured. The proposed parking lock mechanism dispenses with such a detent, inter alia. The application proposes that the positioning of the parking lock mechanism is achieved by means of a self-locking pawl actuator which cannot or cannot be moved from its operating position (rotational position of the pawl actuator shaft) by means of the force introduced via the pawl lever 10 in the planned operation. In the embodiment shown, the pawl actuator 6 is plugged directly onto the actuation mechanism.

[0028] By means of the proposed application, it is achieved that additional components and interfaces of the parking lock mechanism are removed. The position monitoring of the pawl actuator shaft 7 is carried out by means of a pawl sensor 13 on the pawl actuator 6. Thus, the tolerance chain of the components participating in the movement transmission of the parking lock mechanism is ensured by the robust target position of the mechanism.

Claims

1. Parking lock mechanism for a motor vehicle, which has a drive shaft (1) which is provided for the mechanical transmission of power to at least one drive wheel, and the drive shaft has at least one locking region (2), and a parking pawl (3) is provided for the selective formation of a form-locking connection with the locking region (2), the parking lock mechanism has a locking mode in which the parking pawl (3) is moved into a locking position and forms a form-locking connection with the locking region (2) there, and a driving mode in which the parking pawl (3) is moved into a driving position in which it does not form a connection with the locking region (2), the parking pawl (3) can be pivoted about a pawl axis (4) from the locking position into the driving position, and a pawl spring device (5) is provided which pre-tensions the parking pawl (3) into the driving position, and a pawl operating device is provided which has a pawl actuator (6) with a pawl actuator shaft (7) and has a pawl cone (8) which can be moved by means of the pawl actuator (6) along a cone axis (9) which is oriented parallel to the pawl axis, and which can be moved along the cone axis (9) between a cone driving position and a cone locking position, and the parking pawl (3) is pressed into the locking position against the pre-tensioning of the pawl spring device (5) by the pawl cone (8) in the cone locking position, and in order to move the pawl cone (8) along the cone axis (9) a locking cone lever (10) is provided which can be freely rotated by means of the pawl actuator shaft (7), the rotational forces of the pawl actuator (6), the pawl actuator shaft (7) and the locking cone lever (10) have a common operating rotational axis, and the locking cone lever (10) is directly connected to the pawl actuator (6) by means of the pawl actuator shaft (7).

2. The parking lock mechanism according to claim 1, characterized in that A decoupling spring device with a decoupling spring (11) is provided in the force transmission direction between the pawl actuator shaft (7) and the pawl cone (8).

3. The parking lock mechanism according to claim 2, characterized in that The decoupling spring is configured as an actuator decoupling spring and is arranged between the pawl actuator shaft and the locking cone lever in the force transmission direction from the pawl actuator shaft (7) to the locking cone lever (10) and is configured as a torsion spring, and the operating force from the pawl actuator shaft (7) to the locking cone lever (10) can be transmitted at least partially by means of the actuator decoupling spring.

4. The parking lock mechanism according to claim 3, characterized in that The locking cone lever (10) is rotatably mounted relative to the pawl actuator shaft (7), and the operating force from the pawl actuator shaft (7) to the pawl lever can only be transmitted by means of the actuator decoupling spring.

5. The parking lock mechanism according to any one of claims 2 to 4, characterized in that The decoupling spring is arranged between the locking cone lever and the pawl cone in the force transmission direction from the locking cone lever (10) to the pawl cone (8) and is configured as a lever decoupling spring (11), and the operating force from the pawl actuator shaft (7) to the pawl lever can only be transmitted by means of the actuator decoupling spring. The operating force from the locking cone lever (10) onto the pawl cone (8) can be transmitted at least partially by means of the lever decoupling spring (11).

6. The parking lock mechanism of claim 5, wherein The pawl cone (8) is movably mounted on a pawl spindle (12) along a cone axis (9), and The operating force applied to the pawl cone (8) can be transmitted at least partially or completely by the lever decoupling spring (11).

7. The parking lock mechanism according to any one of claims 1 to 4, characterized in that The pawl actuator (6) is configured as a self-locking actuator.

8. The parking lock mechanism according to any one of claims 1 to 4, characterized in that The pawl actuator (6) has a pawl sensor (13) for determining the position of the pawl actuator shaft (7). The pawl actuator (6) has a pawl sensor (13) for determining the position of the pawl actuator shaft (7).

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