Vehicle braking system

Abstract

The invention relates to a vehicle braking system for a vehicle axle of a two-track vehicle, comprising at least one multi-disc brake (3) with an actuator (21) by which a parking function can be engaged in the multi-disc brake (3) by frictional engagement, i.e., by compression, when the vehicle is parked. According to the invention, the vehicle braking system additionally comprises at least one parking lock (40) with a sliding claw (53) 15 and a cooperating fixed claw (55). When the parking function is engaged in the multi-disc brake (3), the parking lock (40) can be activated automatically, so that the parking function is realized not only by the engaged multi-disc brake (3) but also by the positive engagement of the parking lock (40).

Description

[0001] The invention relates to a vehicle braking system according to the preamble of claim 1.

[0002] A vehicle braking system of this type features a multi-disc brake acting on the vehicle axle on each side of the vehicle, instead of conventional disc or drum brakes. This brake allows the vehicle to be engaged or disengaged for braking while driving or for parking when the vehicle is parked. The multi-disc brake has two independently operating actuators: a brake actuator and a parking actuator. These are controlled by a control unit using electrical or hydraulic signals. For safety reasons, the brake actuator can be designed to be normally open (non-self-locking), while the parking actuator can be normally closed (self-locking). Integrating these two actuators into the multi-disc brake requires additional installation space and involves considerable design complexity.

[0003] Furthermore, the following problem arises if the parking actuator performs the parking function solely through frictional engagement, i.e., by pressing the clutch plates of the multi-disc brake: For safety reasons, the parking actuator must be appropriately sized to ensure sufficient frictional engagement in various parking situations. Such situations include, for example, parking on a slope or a malfunction where only the parking actuator on one side of the vehicle is functional, while the one on the other side is inoperative. Additionally, the creep coefficient of the multi-disc brake must be considered when designing the parking actuator.

[0004] DE 10 2021 209 488 A1 discloses an electric vehicle with a braking system. DE 10 2014 102 831 A1 discloses a parking lock arrangement with a pawl and a cooperating locking gear. When the parking function is engaged, the pawl can be brought into locking engagement with a locking gear. EP 3 428 021 A1 discloses another parking lock arrangement that can be actuated by an electric motor.

[0005] The problem is solved by the features of claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

[0006] The invention relates to a vehicle braking system that includes – preferably for each side of the vehicle – a multi-disc brake with an actuator. With the aid of the actuator, a parking function is engaged in the multi-disc brake by frictional engagement, i.e., by pressing the disc pack together, when the vehicle is parked. To allow the actuator to be dimensioned smaller compared to the prior art, the following measure is provided according to the characterizing part of claim 1: In addition to the actuator, the vehicle braking system has at least one parking lock with a sliding claw and a cooperating fixed claw. As soon as the actuator engages the parking function in the multi-disc brake, the parking lock is automatically activated. Therefore, according to the invention, the parking function is realized not only by the engaged multi-disc brake but also by the positive engagement of the parking lock.In the braking concept according to the invention, the installation space required for the actuator and its component weight can therefore be reduced, since the parking function engaged by the electrically controlled actuator is supported by the additional parking lock. The requirements for the electrically controlled actuator with regard to holding torque are therefore reduced compared to a vehicle braking system that does not have a parking lock.

[0007] In one technical implementation, the actuator can have a pressure mechanism acting on the multi-disc brake. This mechanism consists of a pair of discs: a fixed disc that is axially adjustable but rotationally fixed, and a loose disc that is rotatable but axially unadjustable. Between the two discs is at least one ball-ramp unit, in which a ball rolls along inclined parking ball tracks facing each other, or can be brought into sliding contact with each other on inclined sliding ramps.

[0008] The parking function can be engaged as follows: An electric rotary drive of the actuator moves the loose disc from a zero rotation position in a parking direction until it reaches the park position. Upon reaching the park position, the sliding claw automatically engages positively with the fixed claw, thereby activating the parking lock.

[0009] In one specific design variant, the sliding claw can be part of a sliding sleeve. This sleeve is movable coaxially to the disc pair between a release position and a locking position, in which the parking lock is activated.

[0010] Preferably, the parking lock is not actuated by a separate parking lock actuator, but rather automatically, upon reaching the loose-disc parking position. For such automatic actuation, the sliding sleeve can have a control contour. The sliding sleeve can be spring-loaded with its control contour against a loose-disc counter contour in the direction of the locking position. Upon reaching the loose-disc parking position, the control and counter contours can release an axial stroke of the sliding sleeve, over which the spring-loaded sliding sleeve automatically moves from the release position to the locking position, with at least a partial release of the spring preload.

[0011] To engage the parking function, the loose disc can be adjusted in a direction of rotation opposite to the parking direction. In this case, the frictional connection in the multi-plate brake is reduced; at the same time, the control and counter contours, under sliding friction and with the build-up of spring preload, adjust the sliding sleeve back into its release position.

[0012] With the parking lock engaged, any rotating drivetrain component of the vehicle axle is fixed to the axle housing. To implement the parking lock, the sliding claw can be axially adjustable but fixed to the axle housing. Alternatively, the fixed claw can be located on the rotating drivetrain component. For example, the fixed claw can be attached to an inner plate carrier of the multi-plate brake, which is fixed to a flange shaft of the axle leading to the vehicle wheel. Another option is to attach the fixed claw to the differential housing of an axle differential.

[0013] For example, the sliding sleeve control contour can have at least one control gap that interacts with at least one control tooth of the loose disc counter contour. Upon reaching the loose disc park position, a "control tooth-on-control gap" position exists, in which the control tooth is in axial overlap with the control gap formed in the sliding sleeve. This releases the sliding sleeve stroke, and the spring-loaded sliding sleeve moves axially towards the locking position, utilizing the sliding sleeve stroke, until an axial stop formed in the control gap comes to rest against the loose disc control tooth.

[0014] A space-saving arrangement of the assembly consisting of the parking lock and actuator is of great importance. Against this background, the loose and fixed discs of the actuator can be designed in an annular shape. The control tooth of the loose disc can project radially inwards from the inner circumference of the loose disc. The sliding sleeve can extend axially through the inner surfaces of the annular loose and fixed discs, thus minimizing installation space requirements.

[0015] The rotationally fixed mounting of the sliding sleeve with respect to the vehicle axle housing can be implemented in various designs: For example, the sleeve-shaped sliding sleeve can have internal teeth that mesh with a housing-fixed toothed body arranged radially inside the sliding sleeve. Alternatively, the sliding sleeve can have external teeth that mesh with corresponding internal teeth formed on the inner circumference of the fixed disc.

[0016] Furthermore, the sliding claw and the cooperating fixed claw can each be aligned in the axial direction. Alternatively, the sliding claw can be designed as an external toothing on the outer circumference of the sliding sleeve. The corresponding fixed claw, on the other hand, can be an internal toothing formed on the drive train component, into which the sliding sleeve's external toothing can engage in the axial direction, similar to a splined connection.

[0017] Two embodiments of the invention are described below with reference to the accompanying figures.

[0018] They show: Fig. 1 to 12 different views, based on which the structure and function of the vehicle braking system according to the invention are described.

[0019] In the Fig. Figure 1 shows an electrified vehicle axle with an electric motor EM and a gearbox. The electric motor EM is connected to a high-voltage battery (not shown). Conventional wheel disc or drum brakes are omitted from the vehicle axle. Instead of such conventional wheel brakes, the vehicle axle has a multi-disc brake 3 on each side, by means of which vehicle braking can be performed. In addition, the vehicle axle has a [missing information - likely a component or component] on each side. Fig. 1 or Fig. 2 parking barriers 40 (not shown), the structure and function of which will be explained later using the Fig. 9 to 13 are described.

[0020] The EM electric machine is in the Fig. 1 is connected via its rotor shaft 5, with an intermediate reduction stage 7, to the input side of an axle differential 9. The output sides of the differential are driven by output shafts 11 and connected to the vehicle wheels. In the Fig. 1 The electric motor EM is installed transversely in the vehicle axle. Accordingly, the rotor shaft 5 and the output shafts 11 are parallel to each other. Likewise, the two multi-disc brakes 3 installed in the vehicle axle are aligned parallel to each other in the transverse direction y of the vehicle.

[0021] Viewed in the transverse direction y of the vehicle, the axle has one of the multi-disc brakes 3 on each side of the vehicle. These can be controlled by an electronic control unit (not shown) to perform uniform or uneven braking at both vehicle wheels.

[0022] The reduction gear stage 7 is driven by an input-side axle differential gear 13. The axle differential gear 13 is rotationally fixed to a rotating differential housing 15. According to the Fig. 1 drives the axle differential 9 with the multi-plate brakes 3 open in the transverse direction y of the vehicle in a 50 / 50 distribution on both sides to the two output shafts 11 leading to the vehicle wheels.

[0023] In the Fig. 1. The two multi-disc brakes 3 each act directly on the output shafts 11. This means that the multi-disc brake 3 is connected to the respective output shaft 11 via its inner disc carrier 18, while the outer disc carrier 17 is fixedly connected to a housing wall of a vehicle axle housing 19. The disc assembly 20 located between the outer disc carrier 17 and the inner disc carrier 18 can be subjected to contact pressure via an actuator 21. The two actuators 21 can be controlled by the control unit by means of electrical signals.

[0024] One of the actuators 21 is in the Fig. Figures 2 to 3c illustrate this. It consists of an indicated spindle drive 16 with an electric motor, which is drivenly connected to a toothed section 31 of a loose disk 27. The loose disk 27, together with a fixed disk 25, forms part of a clamping mechanism. The fixed disk 25 is connected to a Fig. The two indicated torque supports 14 are supported circumferentially. In addition, the fixed disk 25 is supported axially on a counter support 12. The clamping mechanism has a total of four circumferentially distributed ball-ramp units 23, as can be seen from the Fig. 3a to 3b. Each ball-ramp unit 23 is arranged between the pair of disks and has a ball 29 that rolls between the two disks 25, 27.

[0025] The lamellar assembly 20 located between the outer lamella carrier 17 and the inner lamella carrier 18 can be subjected to contact pressure by means of the actuator 21. Depending on the control of the actuator 21, a braking function for vehicle braking while driving, or alternatively a parking function when the vehicle is parked, can be engaged or disengaged. A key aspect of the invention is that both the braking function and the parking function can be engaged or disengaged by means of the actuator 21. For safety reasons, the electrically controlled actuator 21 is not self-locking when the braking function is engaged. In contrast, the electrically controlled actuator 21 is self-locking when the parking function is engaged.

[0026] As from the Fig. As can be seen from Figures 3a to 3c, each of the ball-ramp units 23 has ball ramps 34 and spaced-apart sliding ramps 38 that act between the disks 25, 27. The balls 29 of the four ball-ramp units 23 are, according to the Fig. 3b was led into a cage 30. In the Fig. 4a and Fig. 4b is one of the ball-ramp units 23, each shown in its unfolded state. Fig. Figure 4a shows two corresponding sliding ramps 38 of the disk pair, while the Fig. 4b shows two corresponding ball ramps 34 of the disk pair with an intermediate ball 29.

[0027] Each of the ball ramps 34 consists of a braking ball track 35 and a parking ball track 37, which merge into each other at a ramp depression 39. In the Fig. 4a The ball 29 is located in the ramp recess 39. The ramp recess 39 defines a zero rotation position 0, in which the pair of discs exerts no contact pressure on the lamellar assembly. The ball ramps 34 of the two discs 25, 27 are point-symmetrical with respect to the ball 29. In addition, the parking ball track 37 and the braking ball track 35 of each ball ramp 34 are symmetrical with respect to an axis of symmetry passing through the ramp recess 39, with equal angles of inclination.

[0028] Depending on a direction of rotation D B , D PThe loose disc 27 can be used either for a braking function for vehicle braking while driving, or alternatively for a parking function when the vehicle is parked. As mentioned above, the disc pair of actuator 21 is not self-locking when the braking function is engaged. In contrast, the disc pair of actuator 21 is self-locking when the parking function is engaged.

[0029] In the Fig. 4a and Fig. Figure 4b shows the pair of discs in their zero rotation position 0. In the zero rotation position 0 (unlike in the Fig. (as shown in 4a) the two sliding ramps 38 are out of contact. The ball 29 is located according to the Fig. 4b in rolling contact in the ramp recesses 39 of the ball ramps 34 of the two discs 25, 27.

[0030] The following will be based on the Fig. Sections 5a to 6b initially describe how to engage the brake function. Starting from the point described in the Fig. 4a and Fig. In the zero position shown in 4b, the loose disc 27 is in a braking direction of rotation D. B via a brake rotation angle to the left into a brake adjustment range S B The ball 29 is adjusted. As a result, it rolls on the two brake ball tracks 35 of the disc pair, with axial spreading of the disc pair over an axial spreading path s. In this way, the lamellar pack 20 of the lamellar brake 3 is subjected to contact pressure. The contact pressure varies depending on the size of the brake rotation angle.

[0031] Immediately after leaving the zero rotation position 0, the loose disc 27 is adjusted by an axial spreading distance s, thereby eliminating any play in the lamellar assembly 20. Further rotational adjustment of the loose disc 27 within the brake adjustment range S B A Kisspoint KP ( Fig. 5b) is achieved, in which the lamellar brake 3 transmits a measurable, predefined torque. In the Kisspoint KP, the loose disc 27 (starting from the rotational zero position 0) is adjusted by a first axial spreading path Δs1. In the Fig. 6a and Fig. 6b the loose disk 27 is adjusted by a second axial spreading path Δs2 to an end position.

[0032] When the braking function is engaged, a low rolling resistance – compared to static friction – acts between the ball 29 and the brake ball tracks 35 of the disc pair. This low rolling resistance means that the ball-ramp units 23 are not self-locking. Consequently, in the event of a power failure, the braking effect of the actuated actuator 21 would decrease, thus fulfilling safety requirements.

[0033] To deploy the brake function, the loose disc 27 is moved from its end position ( Fig. 6a and Fig. 6b) opposite to the direction of braking rotation D Bback to the zero rotation position 0 ( Fig. 4a and Fig. 4b) adjusted.

[0034] During the adjustment movement in the brake adjustment range S B The corresponding inclined sliding ramps 38 remain out of contact with each other, ensuring smooth rotation of the loose disk 27, in which the balls 29 are in rolling contact with the brake ball tracks 35 of the disk pair.

[0035] Based on the Fig. Sections 7a to 8b below describe how to engage the parking function. Starting from the position shown in the Fig. 4a and Fig. In the zero position shown in 4b, the loose disk 27 is moved by means of the electric spindle drive 16 to engage the parking function in a direction of rotation D relative to the braking direction. B opposite parking direction D P via a parking swivel angle into a parking space S P twisted to the right.

[0036] According to the Fig. 7b is parking area S P subdivided into a first sub-area S P1 and into a second sub-area S P2 In the first sub-area S P1 The ball 29 rolls between the facing parking ball tracks 37 of the pair of discs, while the corresponding sliding ramps 38 are still out of contact. In contrast, in the second sub-area S P2 The sliding surfaces 38 are in sliding contact with each other, while the ball 29 is out of rolling contact with the disc pair. To engage the parking function, the loose disc 27 is moved from the zero rotation position 0 in the parking rotation direction D. P to a parking rotation angle in the first sub-area S P1 until reaching a transfer point U, as described in the Fig. 7a and Fig. 7b is indicated. According to the Fig. 7a and Fig. 7b generates a third axial spreading path Δs3 at the transfer point U of the disk pair.

[0037] During the adjustment movement in the first sub-area S P1 The ball 29 rolls along the parking ball tracks 37 of the disc pair, with axial spreading of the disc pair, thus eliminating any play in the lamellar brake 3. Upon passing the transfer point U, the loose disc 27 is moved into the second sub-area S with a further increasing parking rotation angle. P2 twisted until the parking function is engaged.

[0038] With regard to ensuring reliable engagement of the parking function, the parking space S P The transfer point U is positioned between the rotation zero position 0 and the kiss point KP. When the parking function is engaged, the transfer point U is therefore passed shortly before reaching the kiss point KP. Upon reaching the kiss point KP, the two corresponding sliding ramps 38 are already in sliding contact with each other, while the ball 29 is out of rolling contact with the two parking ball tracks 37.

[0039] In the Fig. 8a and Fig. 8b the loose disk 27 is rotated to its park end position E, in which the park function is fully engaged. In the engaged park function, the ball 29 is in a predefined ball freewheel position P ( Fig. 8b). The ball freewheel position P is in the Fig. 8b is defined by means of ball track outlets 41 of the parking ball tracks 37. When the parking function is engaged, the ball track outlets 41 are spaced apart from each other in the circumferential direction of the discs by a ball freewheel f, in which the ball 29 rolls with play, i.e., without rolling contact, between the parking ball tracks 37 of the disc pair. The contact pressure of the disc pair is therefore generated exclusively by means of the sliding ramps 38 in sliding contact.

[0040] To engage the parking function, the loose disc 27 is turned in the opposite direction to the parking rotation D. PThe ball 29 is rotated back to the zero rotation position 0. The ball 29 remaining in the ball-freewheel position P ensures that it comes into rolling contact with the parking ball track 37 at least approximately at the transfer point U and, upon reaching the zero rotation position 0, is again in the ramp recess 39.

[0041] A key aspect of the invention is that the vehicle braking system has a parking lock 40 on each side of the vehicle, of which in the Fig. Figure 9 indicates the parking lock 40 located on the right side of the vehicle. The parking lock located on the left side of the vehicle is designed as a mirror image with respect to a longitudinal plane of the vehicle.

[0042] In the Fig. The parking lock 40 has a sleeve-shaped sliding sleeve 43, which is aligned coaxially with the output shaft 11 and with the two annular disks 25, 27 of the actuator 21. The sliding sleeve 43 extends in an axially nested arrangement through the inner surfaces of the two annular disks 25, 27 of the actuator 21, thus consolidating the package.

[0043] The sliding sleeve 43, with its internal toothing, is axially adjustable as a splined connection, but rotationally fixed on a radially inner toothed body 47. The toothed body 47 is mounted to a bearing plate 51 of the vehicle axle housing 19 via a screw connection 49. On the axial end face facing the inner lamella carrier 18, the sliding sleeve 43 is formed with a claw 53, hereinafter referred to as the sliding claw, which interacts with a fixed claw 55 formed on the inner lamella carrier 18. Fig. 9 or Fig. 10 The sliding sleeve 43 is in its axially recessed release position, in which its sliding claw 53 is out of positive engagement with the fixed claw 55 of the inner lamella carrier 18. In the Fig. 10 and Fig. Figure 11 shows a schematic representation of a section of a development of the sliding sleeve 43, the sliding claw 53, the fixed claw 55 and the sliding sleeve control (i.e. control contour 54 and loose disc control tooth 61).

[0044] In the Fig. In contrast, the sliding sleeve 43 is moved by a sliding sleeve stroke Δa into a locking position, in which the sliding claw 53 and the fixed claw 55 are in positive engagement. In the locking position, the parking lock is therefore activated, which supports the inner lamella carrier 18 in a housing-fixed manner via the sliding sleeve 43.

[0045] The parking lock 40 can be activated or deactivated automatically without a special parking lock actuator. For this purpose, the sliding sleeve 43 has a control contour 54 on its outer circumference with a circumferential annular shoulder 56, which is interrupted by at least one recessed control gap 57. The sliding sleeve control contour 54 is spring-loaded against a counter contour formed on the loose disc 27 by means of a spring element 59, which is axially supported between the bearing plate 51 and the sliding sleeve 43. The loose disc counter contour has at least one loose disc control tooth 61, which projects radially inwards from the inner circumference of the loose disc. Fig. 9 and Fig. 10 is the circumferential annular shoulder 56 of the sliding sleeve control contour 54 in contact with the loose disc control tooth 61.

[0046] As soon as the slot 27 reaches its parking end position E ( Fig. 8a and Fig. 8b) is reached, the loose-disc control tooth 61 comes into axial contact with the control gap 57 formed on the sliding sleeve 43. Accordingly, the sliding sleeve stroke Δa is released and the spring-loaded sliding sleeve 43 is moved axially towards the locking position by using up the sliding sleeve stroke Δa ( Fig. 11) adjusted until an axial stop 63 formed in the control gap 57 comes into contact with the loose-disc control tooth 61. In the locked position ( Fig. 11) the two sliding and fixed claws 53, 55 are in positive engagement with each other.

[0047] To engage the parking function, the loose disc 27 is rotated in a direction D relative to the parking direction. P The control contour / counter contour of the sliding sleeve 43 and the loose disc 27 are adjusted in the opposite direction of rotation. This causes the control contour / counter contour of the sliding sleeve 43 and the loose disc 27 to return to their release position under sliding friction and with the build-up of spring preload ( Fig. 9 and Fig. 10) moves.

[0048] In the Fig. Figure 12 shows a second embodiment, the basic structure and function of which are identical to the previous embodiment. In contrast to the previous embodiment, the sliding sleeve 43 for a rotationally fixed sliding sleeve bearing on the vehicle axle housing 19 has the sliding claw 53, which engages with an internal toothing 67 formed on the inner circumference of the fixed disc. Accordingly, the provision of a toothed body 47 positioned radially inside the sleeve-shaped sliding sleeve 43 can be omitted. Furthermore, in the Fig. 11 the spring element 59 no longer than a wave spring (as in the Fig. 9) realized, but rather as a helical compression spring.

[0049] In the first embodiment of the Fig. 9 and Fig. In the second embodiment, the sliding and locking jaws 53, 55 are aligned in the axial direction. Fig. 11 the sliding claw 53 is designed as an external toothing on the outer circumference of the sliding sleeve, while the corresponding fixed claw 55 is an internal toothing formed on the inner lamella carrier 18, into which the sliding sleeve external toothing can be inserted in the axial direction. REFERENCE MARK LIST: 3-disc brake 5 Rotor shaft 7 reduction gears 9 axle differential 11 Output shaft 12 Counterholds 13 Axle differential gear 14 Torque support 15 Differential housings 16 Rotary drive 17 outer slat carriers 18 internal slat carriers 19 vehicle axle housings 21 Actuator 22 electronic control unit 23 Ball Ramp Unit 25 fixed disk 27 Lottery wheel 29 balls 30 cage 31 Gearing 34 Ball Ramp 35 Brake ball track 37 Park Ball Track 38 sliding ramps 39 Ramp recess 40 parking restrictions 41 Marble Run Run 43 Sliding sleeve 44 Sliding sleeve internal toothing 47 Gear bodies 49 Screw connection 51 Storage sign 53 Shifting claw 54 Sliding sleeve control contour 55 Fixed claw 56 circumferential control ring shoulders 57 reset tax loophole 59 Spring element 61 Loose disc control tooth 63 Axial stop Δa sliding sleeve stroke E Park end position Fv spring preload

Claims

[1] Vehicle braking system for a vehicle axle of a two-track vehicle, comprising at least one multi-disc brake (3) with an actuator (21) with which a parking function can be engaged in the multi-disc brake (3) by frictional engagement, i.e. by compression, when the vehicle is parked, wherein, depending on the control of the actuator (21), a braking function for vehicle braking during driving, or alternatively the parking function when the vehicle is parked, can be engaged or disengaged. characterized by , that the vehicle braking system additionally has at least one parking lock (40) with a sliding claw (53) and a cooperating fixed claw (55), and that when the parking function is engaged in the multi-disc brake (3) the parking lock (40) can be activated independently, so that the parking function is realized not only by the engaged multi-disc brake (3), but also by the positive engagement of the parking lock (40). [2] Vehicle braking system according to claim 1, characterized by , that the actuator (21) has a pressure mechanism acting on the lamellar brake (3), which consists of a pair of discs comprising an axially adjustable but rotationally fixed fixed disc (25) and a rotatable but axially unadjustable loose disc (27), and that, to engage the parking function, a rotary drive (16) of the actuator (21) rotates the loose disc (27) from a rotationally neutral position (0) in a parking rotation direction (D P ) is moved into a park position (E), and that upon reaching the park position (E) the sliding claw (53) automatically engages in positive locking with the fixed claw (55). [3] Vehicle braking system according to claim 2, characterized by, that the sliding claw (53) is part of a sliding sleeve (43) which is displaceable coaxially to the pair of disks between a release position and a locking position, in which the sliding claw (53) is in positive engagement with the fixed claw (55). [4] Vehicle braking system according to claim 3, characterized by , that for control between the release position and the locking position the sliding sleeve (43) has a control contour (54), and that the sliding sleeve (43) with its control contour (54) is spring-biased against a counter contour of the loose disk (27) in the direction of the locking position. [5] Vehicle braking system according to claim 4, characterized by , that upon reaching the loose disc parking position (E) the control and counter contours release an axial sliding sleeve stroke (Δa) over which the spring-loaded sliding sleeve (43) moves from the release position to the locking position, with at least partial reduction of the spring preload. [6] Vehicle braking system according to claim 5, characterized by , that to engage the parking function the loose disk (27) in a direction of rotation relative to the parking direction (D P ) opposite direction of rotation (D B ) is adjustable, thereby establishing the force transmission in the lamellar brake (3), and the control and counter contours adjust the sliding sleeve (43) back into the release position under sliding friction and under spring preload. [7] Vehicle braking system according to any one of the preceding claims, characterized by , that the sliding claw (53) is axially adjustable but rotationally fixed to a housing (19) of the vehicle axle, and that the fixed claw (55) is formed on any rotating drive train component (18, 15), such as an inner lamella carrier (18) of the multi-disc brake (3) which is rotationally fixed to an output shaft (11) leading to a vehicle wheel, or on a differential housing (15) of an axle differential (9) of the vehicle axle. [8] Vehicle braking system according to claim 6 or 7, characterized by , that the sliding sleeve control contour (54) has at least one control gap (57) which interacts with at least one control tooth (61) of the loose disc counter contour, and that upon reaching the loose disc parking position (E) a position ‘control tooth on control gap’ exists in which the control tooth (61) enters the control gap (57) while releasing the sliding sleeve stroke (Δa). [9] Vehicle braking system according to claim 8, characterized by , that the loose disk (27) and the fixed disk (25) are designed in an annular shape, and that the control tooth (61) projects radially inwards from the inner circumference of the loose disk, and that in particular the sliding sleeve (43) extends axially through the inner surfaces of the annular loose disk (27) and fixed disk (25) in a package-friendly nested arrangement. [10] Vehicle braking system according to any one of claims 3 to 9, characterized by, that for a rotationally fixed sliding sleeve bearing, an internal sliding sleeve toothing is in tooth engagement with a housing-fixed toothing body (47) arranged radially inside the sliding sleeve (43), or that for a rotationally fixed sliding sleeve bearing, an external sliding sleeve toothing, in particular the sliding claw (53), is in tooth engagement with an internal toothing (67) formed on the inner circumference of the fixed disk.

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