EP3227587A2

EP3227587A2 - Parking lock device

Info

Publication number: EP3227587A2
Application number: EP15794471.1A
Authority: EP
Inventors: Markus Brandenburg
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2014-12-06
Filing date: 2015-11-11
Publication date: 2017-10-11
Also published as: WO2016087018A3; WO2016087018A2; DE102014018123A1

Abstract

The invention relates to a parking lock device (68) for a motor vehicle, comprising at least one actuating unit (69), provided for the actuation of a parking lock, and at least one evacuation slide (100) having at least one pressure chamber (106) with at least one actuation terminal (108) connected to the actuating unit (69). The evacuation slide (100) has at least one control surface (114) associated with the pressure chamber (106), said surface being provided in order to supply a switching force that is dependent on a working fluid pressure in the pressure chamber (106).

Description

Parking lock device

The invention relates to a parking brake device for a motor vehicle.

From DE 10 201 1 109 377 A1 is already a parking brake device for a

Motor vehicle, with an actuating unit which is provided for actuating a parking brake, and with an emptying slide, which has a pressure chamber with an operating terminal connected to the operating terminal known.

The invention is in particular the object of improving the operation of the parking brake. This object is achieved by an embodiment according to the invention

solved according to claim 1. Further developments of the invention will become apparent from the dependent claims.

The invention relates to a parking brake device for a motor vehicle, having at least one actuating unit which is provided for actuating a parking lock, and having at least one discharge slide, which has at least one pressure chamber with at least one actuation port connected to the actuation unit.

It is proposed that the emptying slide has at least one control surface associated with the pressure chamber, which serves to provide one of a

Operating medium pressure in the pressure chamber-dependent switching force is provided. As a result, the operating medium pressure, the pressure chamber of the drain valve of the

Actuator is supplied, as a control pressure to the circuit and / or

Maintaining a valve position of the emptying valve can be used, whereby the emptying valve can be advantageously controlled. It can be realized that the control surface associated with the pressure chamber is provided in a specific operating state of the parking brake resulting from the supply via the pressure chamber the switching force is used, whereby this operating state can be switched and / or maintained particularly safe and reliable. By the pressure chamber associated control surface, the operation of the parking brake can be improved inexpensively. A "pressure chamber" should in particular be understood to mean a volume of the emptying slide which is filled or acted upon by at least one valve position of the emptying slide, wherein the operating medium is preferably supplied via the volume of the actuating unit for engaging and / or disengaging the parking lock. The pressure chamber is preferably through a valve housing of the

Emptying slide, bounded by the pressure chamber associated control surface of a valve housing movable in the valve spool and by one of the pressure chamber associated control surface facing counter surface of the valve spool. The control surface is preferably designed to be larger than the mating surface, as a result of which the force acting on the control surface in the pressure space preferably results in a greater force than by acting on the mating surface in the pressure space of the working medium. Under a

"Actuating connection of the pressure chamber" is to be understood in particular as meaning a hydraulic or pneumatic connection which is provided for supplying a hydraulic or pneumatic pressure chamber to the actuating unit provided for actuating the parking brake Under "provided" in particular specially programmed, trained, designed,

equipped and / or arranged understood.

It is further proposed that the emptying slide is provided to decouple the control surface assigned to the pressure chamber from the provision of the switching force in a first valve position and to use the control surface associated with the pressure chamber to provide the switching force in a second valve position. It can thereby be realized that the pressure prevailing in the pressure chamber

Operating medium pressure resulting switching force only in the second valve position

is provided, whereby a circuit of the second valve position and a

Maintaining the second valve position can be linked to different conditions from each other and in particular can be realized by different operating medium pressures. It can be realized that a first switching force for switching the second valve position during switched second valve position is replaced or supported by a second switching force, which results from the pressure space associated control surface, whereby the first switching force during switched second Valve position of the drain valve can be reduced or even dissolved. As a result, the first switching force after switching the second valve position can be used at least partially for other actuation. Due to the support of the first switching force by the second switching force, the second valve position can be maintained by an operating medium pressure which is smaller than an operating medium pressure which is necessary for switching the second valve position starting from the first valve position. It can be realized that a larger operating medium pressure is necessary for switching the second valve position than for holding the second valve position. As a result, an unwanted leaving the first valve position due to

Operating medium pressure fluctuations, in particular in a dynamic transition at a start of an internal combustion engine of the motor vehicle and / or a shutdown of the internal combustion engine, can be prevented, whereby the result of the supply via the pressure chamber operating state of the parking brake can be kept very safe and reliable. Furthermore, the emptying slide can be configured so that it can be actuated in a hybrid manner, which moves electrically from its first valve position into its second position

Switched valve position and hydraulically or pneumatically in its second

Valve position can be maintained, creating a flexible operation of the

Drainage can be realized energy-saving. It is particularly advantageous if the first switching force also results from an operating medium pressure. The control surface associated with the pressure chamber is preferably provided for

At least support the maintenance of the second valve position.

It is also proposed that the pressure chamber has at least one return port and the emptying slide is provided to connect in the first valve position the control surface associated with the pressure chamber with the return port and to separate in the second valve position the control surface associated with the pressure chamber of the return port. By the connection of the pressure chamber associated control surface with the return port assigned to the pressure chamber

Control surface particularly simple and reliable decoupled from the provision of switching power. Furthermore, the actuator unit may be decoupled during decoupling

Control surface over the pressure chamber quickly emptied. Under a "return port of the pressure chamber" is in particular a hydraulic or

be understood pneumatic connection, which is provided for emptying the pressure chamber of the provided for actuating the parking lock actuator. Of the

Pressure chamber of the emptying slide is preferably connected via the return port to a pressureless resource reservoir. In particular, it is advantageous if the parking brake device has at least one parking slide, which is intended to divert an operating medium pressure for the actuating unit, wherein the pressure chamber of the emptying slide has at least one supply port which is connected to supply the pressure chamber with the diverted operating medium pressure to the parking lock slider, and wherein the emptying slide is provided for separating the control surface associated with the pressure chamber from the supply connection in the first valve position and the control surface associated with the pressure chamber in the second valve position

Connect supply connection. By connecting the control surface associated with the pressure chamber with the supply connection, the control surface associated with the pressure chamber can be used in a particularly simple and reliable manner for the provision of the switching force. Furthermore, the actuating unit can advantageously be actuated via the pressure chamber during the utilized control surface. By the valve positions of the emptying valve can also be determined whether by the

Parksperrenschieber diverted operating medium pressure of the actuator unit or the resource reservoir is supplied. Through an interaction between the

Parking lock slider and the drain valve can be a redundant

Parksperrenbetätigungssystem be realized, whereby the parking brake can be particularly safe and reliable on and interpreted. In particular, the parking brake can be safely and quickly inserted and the inserted state can be reliably maintained. A "supply connection of the pressure chamber" should in particular be understood to mean a hydraulic or pneumatic connection which is provided for supplying the pressure space of the emptying slide with a working medium

Pressure chamber of the emptying slide is preferably connected via the supply connection in terms of operational resources to an equipment pressure system or connectable. The pressure chamber of the emptying slide is preferably provided to the

Actuator with the branched off by the parking lock slider

To supply operating medium pressure to empty the actuator unit and to keep the second valve position at least.

Furthermore, it is advantageous if the emptying slide has at least one first control chamber and a control surface assigned to the first control chamber, which are connected to the first control chamber

Provision of a dependent of an operating medium pressure in the first control room switching force is provided, wherein the first control space associated control surface and the pressure chamber associated control surface are aligned rectified with respect to a switching direction to each other. As a result, the pressure prevailing in the pressure chamber of the emptying valve operating medium pressure with which the operation of the Parking lock provided actuator is supplied to maintain the switched by the prevailing in the first control room operating medium pressure valve position can be used. The second valve position can by a first

Switched operating medium pressure and above a second operating medium pressure, which is less than the first operating medium pressure maintained. The control chamber is preferably limited by the valve housing of the emptying slide and the control space associated with the control surface of the valve spool. The control surfaces, the

are aligned rectified with respect to the switching direction to each other, are

preferably provided for valve spool movement in the same valve position. The operating medium pressures acting on the control surfaces which are rectilinearly oriented with respect to the switching direction act preferably on the valve spool movement in the same valve position.

Furthermore, it is advantageous if the emptying slide is provided in the first valve position associated with the first control chamber control surface and the

Pressure chamber associated control area to separate from each other and in the second

Valve position associated with the first control room control surface and the

Pressure chamber associated control surface to connect with each other. As a result, the operating medium pressure, which in the first valve position only to the first

Control space associated control surface acts through the circuit in the second

Valve position additionally act on the pressure chamber associated control surface, whereby at the same operating medium pressure, a larger control surface is effective and thus results in a higher switching force at the same operating pressure. It can be realized that after switching the emptying slide in the second valve position, the pressure chamber associated control surface is effective, which can ensure that the second valve position even with pressure drop below necessary for switching the second valve position operating medium of the emptying valve in the second valve position remains switched.

In a particularly advantageous embodiment, the emptying slide is provided to connect in the first valve position only the control surface associated with the first control chamber to the parking lock slider and in the second valve position the first control chamber associated control surface and the pressure chamber associated control surface to the parking lock slide. As a result, it can be realized that the operating medium pressure branched off from the parking slide valve only then passes over the

Emptying the actuation unit is supplied, if this is a first

Threshold exceeds and only then via the drain valve of the Actuator is discharged when it falls below a second pressure threshold, wherein the second pressure threshold is smaller than the first pressure threshold. The second

Threshold is preferably below a smallest, during operation of the

Motor vehicle driven, diverted by the parking lock slider

Operating medium pressure, whereby during operation, an inadvertent switching of the discharge valve can be prevented in the first valve position. The first

Pressure threshold is preferably dimensioned so that unintentional switching of the emptying slide is prevented in the second valve position, in particular in the dynamic transition when starting the engine.

Furthermore, it is advantageous if the emptying slide has at least one second control chamber and a control surface assigned to the second control chamber, which is provided for providing a switching force dependent on an operating medium pressure in the second control chamber, the control surface assigned to the second control chamber and the pressure chamber associated with the second control chamber Control surface are oriented with respect to a switching direction opposite to each other. This can be a

Shifting force can be provided in the direction of the first valve position, whereby the

Control of the drain valve can be improved. In particular, the circuit of the second valve position can be selectively prevented thereby. The control surfaces, which are oriented opposite to each other with respect to the switching direction, are preferably provided for valve spool movement in opposite valve positions. The operating pressures acting on the control surfaces opposing each other with respect to the switching direction act to

Valve slide movement preferably in opposite valve positions.

It is also proposed that the parking brake device be provided for locking the actuator unit locking unit and at least one

Parksperrenschieber, which is intended to divert in a first valve position, an operating medium pressure for the operating unit and in a second

Valve position branch off an operating medium pressure for the locking unit has. As a result, the branched off by the parking lock slider

Operating medium pressure can be used either to actuate the parking brake or to actuate the locking unit, creating a particularly compact

Parking lock device can be provided. By the valve positions of the parking lock slider can be determined whether the parking brake is to be inserted or designed. The actuating unit can be performed to actuate the parking brake as a single-acting cylinder-piston unit, which is a spring force Has switching direction and an operating medium pressure-related switching direction. By switching the parking lock slider in the first valve position is the

Actuator preferably operated in the operating medium pressure-related switching direction, provided that the emptying slide is switched to its second valve position and the actuating unit is unlocked. By switching the parking brake slide in the second valve position, the actuating unit is preferably unlocked and actuated by a spring in the spring-force-induced switching direction.

Furthermore, it is proposed that the locking unit has an actuating-technology control and an electromagnetic control which acts in parallel to the operational-technical control. As a result, a redundant unlocking of the actuating unit can be realized, so that in the event of a failure of the

operational technical control or the failure of the electromagnetic control used the other control for unlocking and the

Actuator so that even in case of failure can be unlocked. By "parallel" is to be understood in this context, in particular, that a producible by the electromagnetic control force and by the

power technical control provided force have the same effect and that is unlocking the actuator unit.

Preferably, the first valve positions are each formed as basic positions. A "basic position" is to be understood in particular a valve position of a slide, which assumes the slider without concern of a control pressure, whereby the slide preferably the basic position even when standing

Internal combustion engine occupies.

Further advantages will become apparent from the following description of the figures. In the figures, an embodiment of the invention is shown. The figures, the description of the figures and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Showing:

Fig. 1 is a hydraulic system of an automatic transmission, with a

Parking lock device and

Fig. 2, the parking brake device. FIG. 1 shows a hydraulic system of an automatic transmission of a motor vehicle. The automatic transmission is for example as a transmission with several coupled

Planet sets executed. It is designed in particular as an automatic transmission according to DE 10 2008 055 626 A1 of the applicant. The automatic transmission can also be used, for example, as an automated change-speed gearbox, as

Double clutch transmission or be designed as a continuously variable transmission.

The hydraulic system has a main pump 10, which is driven by an internal combustion engine 1 1. The main pump 10 sucks through a suction filter 12 resources from a resource reservoir 13. In Fig. 1 drains to a resource reservoir are shown at several points. This is to be understood that resources from these drains directly or indirectly enters the resource reservoir 13. In the resource reservoir 13, excess resources are collected.

The main pump 10 conveys the operating fluid into a working pressure line 14, which supplies a working pressure slide 15 with the operating medium. In the working pressure line 14, a check valve 16 is arranged, which is designed so that the

Can flow from the main pump 10 to the working pressure slide 15, but not vice versa. The operating means is designed as a transmission oil.

The working pressure slide 15 is designed as a normally constructed control slide, acts on the control pressure as set by a control solenoid valve working pressure 17 operating medium pressure. Together with a spring force which sets a base pressure of the working pressure, the control pressure acts against the recirculated from the working pressure line 14 working pressure. By changing the operating pressure set by the control solenoid valve working pressure 17, the level of the working pressure can be adjusted. When the working pressure reaches that of the control solenoid valve working pressure 17

set value, so is the working pressure slide 15 via a

Lubricating pressure line 18 made a connection between the working pressure line 14 and a lubricating pressure slide 19. The lubricating pressure slide 19 is thus supplied with equipment only when the working pressure has reached its set by Regelmagnetventil- working pressure 17 setpoint. The working pressure slide 15 thus controls the working pressure in the working pressure line 14 to the set by Regelmagnetventil- working pressure 17 setpoint. The lubricating pressure slide 19 is also designed as a normally constructed control slide, acts on the control pressure as set by a control solenoid valve lubrication pressure 20 operating medium pressure. The control solenoid lubrication pressure 20 may thus be referred to as a pilot valve. Together with a spring force which sets a base pressure of the lubricating pressure, the control pressure acts against the returned from the lubricating pressure line 18 lubricating pressure. By changing the operating medium pressure set by the control solenoid valve lubrication pressure 20, the amount of lubrication pressure can be adjusted. When the lubrication pressure reaches the set value, the lubrication pressure slide 19 establishes a connection between the

Lubricating pressure line 18 and a return line 21 made. About the

Return line 21, the resource to a suction line 22, the

Main pump 10 with the suction filter 12 connects, returned. Of the

Lubricating pressure slide 19 thus controls the lubricating pressure in the lubricating pressure line 18 to the set by the control solenoid valve lubrication pressure 20 setpoint. Of the

Lubricating pressure slide 19 is designed so that the maximum required

Lubricating pressure is achieved at a control pressure of about 3 bar. the

Lubricating pressure slide 19 is thus assigned an operating medium pressure range of 0 to 3 bar. If the control pressure continues to rise, so does the set

Lubricating pressure continues.

The control solenoid valve working pressure 17 and the control solenoid valve lubrication pressure 20 are both configured as so-called direct control valves. In direct control valves, a force acts from an electronic control device, not shown

controlled electromagnet directly as a control force on a slider. Against the control force act a spring force and a returned operating medium pressure whose height is to be set by the direct control valve according to the control of the electronic control device. The operating fluid pressure set by a direct control valve is derived from a supply pressure. In the case of

Control solenoid valve working pressure 17 and the control solenoid valve lubrication pressure 20 is the working pressure in the working pressure line 14 as a supply pressure.

The hydraulic system can also have a connection, not shown, via which a controllable Drehmomentverteilvorrichtung for a four-wheel drive of

Motor vehicle can be supplied with working pressure.

The hydraulic system has, in addition to the main pump 10, an additional pump 23, which is controlled by an electric motor 24 controlled by the electronic control device can be driven. The auxiliary pump 23, on the one hand, the main pump 10 in situations where the delivery rate of the main pump 10 is insufficient, support, with a maximum achievable operating medium pressure of the auxiliary pump 23 is significantly lower than a maximum operating medium pressure of the main pump 10. On the other hand, the auxiliary pump 23 a Basic supply of hydraulic system with stationary

Ensure combustion engine 1 1 and thus standing main pump 10. The

Additional pump 23 also sucks on the suction filter 12 from the resource reservoir

13 resources. It conveys the operating medium in an additional pump line 25, which is connected via a check valve 26 to the working pressure line 14. The check valve 26 is arranged so that the operating means of the

Additional pump line 25 can flow into the working pressure line 14, but not vice versa. Thus, the auxiliary pump 23 in the case in which the working pressure is less than its maximum achievable operating medium pressure, promote together with the main pump 10 in the working pressure line 14. The auxiliary pump line 25 is also connected to an auxiliary pump slide 27. By means of the auxiliary pump slide 27, a connection between the auxiliary pump line 25 and the lubricating pressure line 18 are produced, wherein between the auxiliary pump slide 27 and lubricating pressure line 18, a check valve 28 is arranged so that the resources of

Additional pump slide 27 can flow into the lubrication pressure line 18, but not vice versa. In a illustrated basic position of the auxiliary pump slide 27, said connection between the auxiliary pump line 25 and the lubricating pressure line 18 is interrupted, in a switched position of the auxiliary pump slide 27, said connection is made. On the auxiliary pump slide 27 acts as

Control pressure of the working pressure in the working pressure line 14 against a spring force. The spring force is designed so that the auxiliary pump slider 27 so long in the

Basic position remains until the working pressure exceeds the maximum achievable operating medium pressure of the auxiliary pump 23. If this operating medium pressure is reached, the connection between the auxiliary pump line 25 and the lubricating pressure line 18 is made via the auxiliary pump slide 27 and the auxiliary pump 23 can

Promote resources in the lubrication pressure line 18, in which there is a much lower operating medium pressure than the working pressure. Thus, the auxiliary pump 23 may also support the main pump 10 when the working pressure is greater than their maximum achievable operating pressure and they therefore no longer in the working pressure line

14 can promote.

Via the working pressure line 14 are also solenoid valves 29, 30, 31, 32, 33 and 34 for the actuation of switching elements of the automatic transmission in the form of Multi-plate clutches and brakes supplied with working pressure. The multi-plate clutches and brakes are shown schematically by gear change piston-cylinder units 35, 36, 37, 38, 39 and 40, by means of which the multi-plate clutches and brakes can be closed and opened. The speed change piston-cylinder units 35, 38 and 40 are multi-disc brakes, and the speed change piston-cylinder units 36, 37 and 39 are associated with multi-plate clutches. The control solenoid valves 29, 30, 31, 32, 33 and 34 are constructed identically, so that only the control solenoid valve 29 is explained in more detail. The control solenoid valve 29 is also designed as a direct control valve, which is controlled by the electronic control device, not shown. The

Control solenoid valve 29 is supplied via a connection with working pressure. It is used to set an actuating pressure in a gear change pressure chamber 41 of

Gear change piston-cylinder unit 35 to which it is connected via a line 42. The actuating pressure in the line 42 is returned as control pressure to the control solenoid valve 29. In order to avoid pressure oscillations in the line 42, the actuation pressure is additionally fed back to two further connections of the control solenoid valve 29. As a further measure to avoid pressure oscillations, the line 42 is connected via the control solenoid valve 29 to a pressure accumulator 43. Via a return line 87, the control solenoid valve 29 and the control solenoid valves 30, 31, 32, 33 and 34 is connected to the resource reservoir 13. In the

Return line 87 is a spring-loaded check valve 44 is arranged. The

Check valve 44 is arranged so that the operating fluid in the

Operating fluid reservoir 13 can flow. It is also designed so that it opens the flow in the direction of the resource reservoir 13 only when a minimum pressure of for example 0.2 to 0.4 bar in the return line 87 prevails. This ensures that at least the stated minimum pressure is always present in return treatment 87. This causes the line 42 and the gear change pressure chamber 41 can not idle, but are always filled with resources.

By appropriate control of the control solenoid valve 29 can thus a

Operating pressure in the gear change pressure chamber of the gear change piston-cylinder unit 35 and dismantled and so the gear change piston-cylinder unit 35th

assigned multi-disc brake can be closed and opened. By appropriate control of the control solenoid valves 29, 30, 31, 32, 33 and 34 can thus the

The multi-plate clutches and brakes of the automatic transmission are closed and opened, allowing the individual gears to be engaged and disengaged. The control solenoid valves 29, 30, 31, 32, 33 and 34 and the speed change piston-cylinder units 35, 36, 37, 38, 39 and 40 may thus be referred to as a speed change system 61. With this shown gear change system 61 a total of nine forward gears and one reverse gear can be switched.

The lubricating pressure line 18 is connected via a centrifugal oil valve 45 and a first supply line 63, which is designed as a controllable slide switch, with a converter inlet 46 of a hydrodynamic torque converter 47. On the centrifugal oil valve 45 acts as a control pressure set by the control solenoid valve lubrication pressure 20

Operating medium pressure against a spring force. The spring force is designed so that the centrifugal oil valve 45 changes when exceeding a Betriebsmitteldruckgrenze of, for example, 4 bar from a basic position shown in a switching position. The set by the control solenoid valve lubrication pressure 20 operating medium pressure thus acts both on the lubricating pressure slide 19, and the centrifugal oil valve 45 as the control pressure. The centrifugal oil valve 45 is thus assigned a pressure range of 3 to 5 bar.

In the illustrated basic position of the centrifugal oil valve 45, the lubricating pressure line 18 is connected via the centrifugal oil valve 45 via two connections with the Wandlerzufluss 46. In a first portion 48 of the first supply line 63 between Fliehölventil 45 and converter inflow 46, a diaphragm 49 is disposed in a second, to the first portion 48 parallel portion 50 is no corresponding hydraulic component arranged. The second section 50 is connected to the lubricating pressure line 18 only in the basic position of the centrifugal oil valve 45. By contrast, the first section 48 is always connected to the lubricating pressure line 18. This ensures that in the switching position of the centrifugal oil valve 45, in which, as described above, a very high lubricating pressure acts on the aperture 49 of the working fluid pressure at the converter 46 is lowered so far that damage to the torque converter 47 can be reliably avoided.

After flowing through the torque converter 47, the operating medium flows via a converter outflow 51 to a fluid cooler 52. From the fluid cooler 52 are different lubrication points 53 in the automatic transmission with cooled

Supplied resources.

The torque converter 47 has a lockup clutch 54, which is controlled by a control solenoid valve converter 55. The control solenoid valve converter 55 provides this in accordance with a control by the electronic control device in a line 56 which communicates with a pressure chamber, not shown

Lock-up clutch 54 is connected, an actuation pressure. Of the

Torque converter 47 is thus designed as a so-called 3-channel converter. The Control solenoid valve converter 55 is also designed as a direct control valve and is supplied with working pressure. As a special feature, the control solenoid valve converter 55 as a pilot control of an internal pressure of the torque converter 47, which acts against the operating pressure at the lock-up clutch 54, corresponding

Supplied operating medium pressure. Said operating medium pressure acts in the same direction to the force of the electromagnet of the control solenoid valve 55 and is tapped in a line 58 which is connected via a first aperture 59 to the Wandlerzufluss 46 and a second aperture 60 to the converter outlet 51. With a suitable choice of the orifices 59 and 60, the operating medium pressure in the line 58 corresponds to the internal pressure of the torque converter 47. The mode of operation of the return and the discharge of the internal pressure are described in detail in DE 10 2004 012 117 A1.

The speed change piston-cylinder units 36, 37 and 39 of the multi-plate clutches each have a Fliehölraum 62, which via a Fliehölleitung 64 with the

Operating fluid cooler 52 and thus at least indirectly connected to the first supply line 63. The centrifugal oil space 62 is arranged relative to the gear change pressure chamber 41 with respect to a gear change piston 65, which acts on the multi-plate clutches. If the centrifugal oil chamber 62 is sufficiently filled with operating medium, the pressure increases arising in the gear change pressure chamber 41 and in the centrifugal oil chamber 62 are equalized by the rotation of the gear change piston-cylinder units 36, 37 and 39.

In some situations, for example in certain circuits in the automatic transmission, a functioning centrifugal oil balance, ie, sufficiently filled centrifugal oil spaces 62, is important. In these situations, the centrifugal oil valve 45 can be brought into its switching position via a corresponding operating medium pressure of the control magnetic valve lubricating pressure 20 as described above. In this switching position, a connection between the lubricating pressure line 18 and a second supply line 66, which opens into the centrifugal oil line 64, is produced via the centrifugal oil valve 45. Thus, the centrifugal oil conduit 64 is supplied not only via the first supply line 63 but also via the second supply line 66 resources. Thus, the Fliehölräume 62 of the gear change piston-cylinder units 36, 37 and 39 can be filled very quickly and thus a functioning Fliehölausgleich be achieved.

In the second supply line 66, a diaphragm 67 is arranged. About this aperture 67 and the aperture 49 in the first portion 48 of the first supply line 63 can

Flow rates of the operating medium in the first and second supply line 63, 66 can be adjusted. In the centrifugal oil line 64, a check valve may be so seconded, that a return flow of resources from the second supply line 66 in the direction of the means cooler 52 is prevented.

The hydraulic system further comprises a parking lock device 68, by means of which a parking lock, not shown, of the motor vehicle can be switched on and laid out. The parking lock device 68 is provided to lock by means of a parking pawl, not shown, a gear set of the automatic transmission, not shown, or to fix a not shown shaft of the automatic transmission fixed to the housing. In this embodiment, the parking brake on a non-rotatably mounted on a transmission output shaft of the automatic transmission parking lock gear, with the parking lock pawl for engaging the parking brake is positively engageable engaged. For actuation and thus for putting on and laying the parking brake has the

Parking lock device 68, a hydraulic actuator 69 on. The

Actuator 69 has a parking position in which the parking brake is engaged, and a non-parking position in which the parking brake is designed on. In parking position the parking lock is activated and in the non-parking position the parking lock is deactivated. The parking lock device 68 is shown enlarged in FIG.

The actuator 69 is single-acting. The actuating unit 69 comprises a single-acting actuating cylinder 70, a one-way parking lock piston 71 and an actuating element 72 for actuating the parking brake. The actuating cylinder 70 is provided for the hydraulic movement of the parking brake piston 71 in the non-parking position. The parking lock piston 71 is arranged axially displaceable in the actuating cylinder 70. The parking lock piston 71 is fixedly connected to the actuator 72. They are made in one piece with each other. The parking lock piston 71 is coupled by means of the actuating element 72 in terms of movement with the parking pawl. The actuator 72 is axially displaceable by means of the parking brake piston 71 along its main extension direction 73 in two opposite switching directions 74, 75. The actuator 72 operates the parking pawl. The switching direction 74 is assigned to the non-parking position, ie, an axial movement of the parking brake piston 71 in the switching direction 74 leads to laying out the parking brake. The switching direction 75 is assigned to the parking position, ie, an axial movement of the parking brake piston 71 in the switching direction 75 leads to the insertion of the parking brake. The actuator 72 is formed as an actuating rod. The actuating unit 69 is designed as a piston-cylinder unit. For hydraulic adjustment of the non-parking position, the actuating unit 69 has a pressure chamber 76. The pressure chamber 76 is provided for laying out the parking brake. The actuating element 72 is axially displaceable by a pressurization of the pressure chamber 76 in the switching direction 74. The pressure space 76 is formed by the operation cylinder 70 and the parking lock piston 71 arranged in the operation cylinder 70. The actuating cylinder 70 takes to form the single pressure chamber 76, the parking brake piston 71 movable. The pressure chamber 76 is formed by the actuating cylinder 70 and the actuating element 72 facing the pressure surface 77 of the parking brake piston 71. The pressure surface 77 of the parking brake piston 71 is provided for providing a dependent on an operating pressure in the pressure chamber 76 switching force for disengaging the parking brake.

In order to move the parking brake piston 71 into the parked position, the actuation unit 69 has a spring 78. The spring 78 is provided for autonomous adjustment of the parking position. The spring 78 is provided for unpressurized adjustment of the parking position and thus to adjust the parking position without hydraulic assistance. The spring 78 is operatively disposed between the actuating cylinder 70 and the parking brake piston 71. The spring 78 is intended to be biased by the prevailing in the pressure chamber 76 operating medium pressure. A spring force of the spring 78 counteracts the switching force that can be generated by the operating medium pressure in the pressure chamber 76. The spring force of the spring 78 acts in the switching direction 75. The spring 78 is provided for adjusting the parking position at unpressurized pressure chamber 76. In principle, the spring 78 can also be hydraulically assisted in order to adjust the parking position.

For the positive locking of the actuating unit 69 and thus for the positive locking of the parking brake piston 71, the parking brake device 68 has a mechanical locking unit 79. The locking unit 79 is provided for locking the actuating unit 69 and thus the parking brake piston 71. It is for locking the parking brake piston 71 in the parking position, and thus provided for locking an inserted parking brake. The locking unit 79 is hydraulically unbreakable. It can not be unlocked by an acting on the parking brake piston 71 operating fluid pressure in the pressure chamber 76. In principle, it is conceivable that the locking unit 79 is provided in addition to the locking of the parking brake piston 71 in the non-parking position, and thus for locking a designed parking brake. The locking unit 79 comprises a positive locking contour 80, which is incorporated in the actuating element 72. The actuating element 72 forms the form-locking contour 80. The positive locking contour 80 is assigned to the parking position. The form-fitting contour 80 is formed free of oblique surfaces, ie, it has no friction surfaces, which are provided for frictional locking and thus for hydraulically überdrückbaren lock. In principle, the locking unit 79 may have a further, introduced in the actuator 72 positive locking contour, which is assigned to the non-parking position. Furthermore, it is basically conceivable that the locking unit 79 is formed hydraulically überdrückbar. For überdrückbaren training the positive locking contour 80 may have basically inclined surfaces.

For the positive locking of the parking brake piston 71 in the parking position, the locking unit 79 has a locking element 81. In the parking position, the locking element 81 engages positively in the form-locking contour 80. By engaging the locking element 81 in the form-locking contour 80 of the parking brake piston 71 is locked positively and hydraulically unüberdrückdrückbar. The locking element 81 has a form-fitting contour which corresponds to the form-fitting contour 80 and which is designed to be free of sloping surfaces. The locking unit 79 further has a spring 82 which presses the locking element 81 against the actuating element 72. The spring 82 is intended to be biased by unlocking the actuator 69.

To unlock the parking brake piston 71, the locking unit 79 has a hydraulic actuating unit 88, which is provided to the

Locking member 81 to move against a spring force of the spring 82. The

Actuator 88 releases a positive connection between the

Locking element 81 and the parking brake piston 71. The actuating unit 88 is provided, the locking element 81 hydraulically from the

To move positive locking contour 80. To form a redundant

Unlocking system, the actuator 88 has a hydraulic control 89 and a parallel to the hydraulic control 89 acting electromagnetic control 90. The parking lock piston 71 can be unlocked by the hydraulic driver 89 and by the electromagnetic driver 90.

The provided for unlocking the parking brake piston 71 actuating unit 88 has a pressure chamber, not shown, and a hydraulically movable in the pressure chamber unlocking piston, which is connected to the locking element 81st is connected. By a certain operating medium pressure in the pressure chamber of the actuating unit 88, the unlocking piston and thus the shifts

Locking element 81 in an unlocked position, whereby the parking lock piston 71 is unlocked.

In order to branch off an operating medium pressure for the actuating unit 69 and for the actuating unit 88, the parking brake device 68 has a parking lock slide 91. The parking lock slide 91 has a first valve position shown in the figures and a second valve position (not illustrated). The parking lock slide 91 is in its first valve position for actuating the parking brake and in its second

Valve position for unlocking the parking brake piston 71 is provided. He is intended to be in the first valve position a resource pressure for

Actuator 69 and branch off in the second valve position an operating medium pressure for the locking unit 79. The parking lock slide 91 is intended to divert the working fluid pressure from a working pressure system. The branched off by the parking slide valve 91 operating medium pressure is formed as the working pressure.

The hydraulic control 89 has an unlocking line 116, which the

Parksperrenschieber 91 hydraulically connects to the pressure chamber of the actuator 88. The parking lock slide 91 is provided to supply the diverted operating medium pressure to the pressure chamber of the actuating unit 88 in the second valve position. In the first valve position of the parking lock slide 91 is provided to empty the pressure chamber of the actuator 88. In the second valve position prevails in the pressure chamber of the actuating unit 88 of the diverted by the parking brake slide 91 operating medium pressure through which the parking brake piston 71 is unlocked.

The electromagnetic control 90 has a solenoid valve 1 17. The solenoid valve 1 17 of the electromagnetic drive 90 is via the electronic

Controlled control device. The solenoid valve 1 17 is intended to

Unlocking the parking lock piston 71 to set an operating medium pressure in the pressure chamber of the actuator unit 88 for unlocking the parking lock piston 71 regardless of the parking lock slider 91. In principle, it is conceivable that the solenoid valve 1 17 is provided to support the hydraulic drive 89,

for example, if the branched off by the parking slide valve 91

Operating medium pressure for unlocking the parking brake piston 71 is not sufficient. Furthermore, it is basically conceivable that the electromagnetic control 90 in addition to Solenoid valve 1 17 or alternatively to the solenoid valve 1 17 has a solenoid, which is intended to move the locking member 81 in its unlocked position.

The parking lock slide 91 has to provide the valve positions

Valve slide 92, which is arranged hydraulically displaceable. Furthermore, the parking brake slide 91 has an operatively connected to the valve spool 92 spring 93, which is intended to move the valve spool 92 independently in the first valve position and thus independently the first valve position of

Park Sperrschiebers 91 to switch. The first valve position of the parking lock slide 91 is formed as a basic position.

To provide a switching force acting against the spring 93, the parking slide valve 91 has a first control chamber 94. The first control chamber 94 counteracts a spring force of the spring 93. An operating medium pressure in the first control chamber 94 is provided to move the valve spool 92 against the spring force of the spring 93 and thus from the first valve position. The operating medium pressure in the first control chamber 94 is provided for displacement of the valve spool 92 in the second valve position. The second valve position is formed as a switching position of the parking slide valve 91.

To provide a switching force acting with the spring 93, the parking slide valve 91 has a second control chamber 95. The second control chamber 95 counteracts the first control chamber 94. The control spaces 94, 95 are arranged opposite each other. The second control chamber 95 acts in the same direction to the spring force of the spring 93 on the valve spool 92. An operating medium pressure in the second control chamber 95 is provided to move the valve spool 92 against the operating medium pressure in the first control chamber 94 and thus from the second valve position. The operating medium pressure in the second control chamber 95 is provided for displacing the valve spool 92 into the first valve position. The spring 93 is arranged in the second control chamber 95.

To supply the first control chamber 94 with an operating medium pressure, the first control chamber 94 of the parking slide valve 91 is hydraulically connected to the control solenoid lubricant pressure 20. The parking brake device 68 has a control pressure line 96 which connects the control solenoid valve lubrication pressure 20 hydraulically with the first control chamber 94 of the parking slide valve 91. In the first control chamber 94, the operating medium set by the control solenoid valve lubrication pressure 20 prevails. print. The set by the control solenoid valve lubrication pressure 20 operating medium pressure thus acts on the lubricating pressure slide 19, the centrifugal oil valve 45 and the parking brake slide 91 as the control pressure.

For branching off the operating medium pressure of the parking lock slide 91 is hydraulically connected to the working pressure system. The parking lock slide 91 is hydraulically connected to the main pump 10. The parking lock device 68 has a

Supply pressure line 97, which connects the parking brake slide 91 hydraulically to the working pressure line 14.

To supply the second control chamber 95 with the operating medium pressure, the second control chamber 95 of the parking slide valve 91 is hydraulically connected to the control solenoid valve 31 of the gear change system 61 and to the control solenoid valve 33 of the gear change system 61. The parking brake device 68 has a counter-pressure line 98, which connects the control solenoid valves 31, 33 hydraulically with the second control chamber 95 of the parking slide valve 91. In the second control chamber 95 prevails either the set by the solenoid valve 31 or by the control solenoid valve 33 operating medium pressure. The second control space 95 of the parking lock slider 91 is hydraulically connected to the speed change pressure chambers 41 of the speed change piston-cylinder units 37 and 39.

With a correspondingly high operating medium pressure in the second control chamber 95 of the

Parksperrenschiebers 91 of the parking brake slide 91 remains in the first valve position when the connected to the first control chamber 94 Regelmagnetventil- lubricating pressure 20 sets a working fluid pressure at which the Fliehölventil 45 is in its switching position in which a fast filling of the Fliehölraums 62 is possible. This is also guaranteed if, due to tolerances, wear or aging, the pressure ranges have shifted and overlap. The back pressure line 98 is connected via a ball switching valve 99 with the gear change pressure chambers 41 of the

Gear change piston-cylinder units 37 and 39 connected. The ball switching valve 99 is arranged so that the higher of the two in the aforementioned gear change pusher spaces 41 as back pressure in the second control chamber 95 of the

Parking lock slide 91 acts. Is one of the two gear change piston-cylinder units 37 and 39 associated with multi-plate clutches actuated and thus closed, the back pressure is sufficiently large to the change of

Parksperrenschiebers 91 to prevent the second valve position. The hydraulic system is designed so that one of the two clutches is closed in all gears, in which a control of the centrifugal oil valve 45 may be necessary.

When shifting the parking brake piston 71 in the switching direction 75 and thus in the parking position, the operating means from the pressure chamber 76 of the provided for actuating the parking lock actuator 69 must be removed. In order for this to be possible quickly and only with little resistance, the parking brake device 68 has an emptying slide 100 with large flow cross-sections, which is connected to the pressure chamber 76. The emptying slide 100 is hydraulically between the

Parking lock slide 91 and provided for operating the parking brake

Actuator 69 is arranged. It is arranged hydraulically between the parking slide valve 91 and the pressure chamber 76 of the actuator 69. The emptying slide 100 is provided to the parking lock slide 91 hydraulically from the

Actuator 69 to decouple.

The emptying slide 100 has a first valve position shown in the figures and a second valve position (not shown). The emptying slide 100 is provided to hydraulically separate the parking slide valve 91 in the first valve position of the pressure chamber 76 of the actuator 69 and hydraulically connect the parking slide valve 91 in the second valve position with the pressure chamber 76 of the actuator 69. In the first valve position of the emptying slide 100, the pressure chamber 76 of the actuating unit 69 is emptied via the emptying slide 100. As a result, the operating medium from the pressure chamber 76 does not have to be removed via the parking slide valve 91 with significantly smaller flow cross-sections into the working fluid reservoir 13, but can move into the working fluid reservoir 13 without great resistance via the drainage slide 100

Drain working fluid reservoir 13.

In the second valve position of the emptying slide 100, the pressure chamber 76 of the actuating unit 69 via the emptying slide 100 with that of the

Parking lock slide 91 supplied branched operating medium pressure. If the

Parksperrenschieber 91 in the first valve position and the emptying slide 100 are connected in the second valve position prevails in the pressure chamber 76 of the

Actuator 69 of the branched off from the parking lock slider 91

Equipment pressure and thus the working pressure. When the parking lock slider 91 in the first valve position and the emptying slide 100 are switched in the second valve position, the working pressure line 14 via the parking lock slider 91 and the

Draining slide 100 connected to the pressure chamber 76, so that this resource is supplied from the working pressure system. When the parking lock slider 91 is switched in the second valve position or the emptying slide 100 in the first valve position, the pressure chamber 76 of the actuating unit 69 is depressurized. If the

Parksperrenschieber 91 is connected in the second valve position, which is

Working pressure line 14 via the parking lock slide 91 with the pressure chamber of the

Actuator 88 connected.

The emptying slide 100 has a valve slide for providing the valve positions

101, which is arranged hydraulically displaceable. Furthermore, the emptying slide 100 has an operatively connected to the valve spool 101 spring 102, which is intended to move the valve spool 01 independently in the first valve position and thus independently switch the first valve position of the emptying slide 100. The first valve position of the emptying slide 100 is formed as a basic position.

To provide a force acting against the spring 102, the emptying slide 100 has a first control chamber 103. The first control chamber 103 counteracts a spring force of the spring 102. An operating medium pressure in the first control chamber 103 is provided to move the valve spool 101 against the spring force of the spring 102 and thus from the first valve position. The operating medium pressure in the first control chamber 103 is provided for displacing the valve spool 101 into the second valve position. To provide a switching force acting in the second valve position, the emptying slide 100 has a first control surface 104, which is assigned to the first control chamber 103. The first control surface 104 is provided for providing a dependent of the operating medium pressure in the first control chamber 103 switching force in the second valve position. The operating medium pressure prevailing in the first control chamber 103 acts on the first control surface 104. The valve slide 101 has the first control surface 104. The second valve position is designed as a switching position of the emptying slide 00.

To provide a switching force acting with the spring 102, the emptying slide 100 has a second control chamber 105. The second control chamber 105 counteracts the first control chamber 103. The control spaces 103, 105 are arranged opposite to each other. The second control chamber 105 acts in the same direction to the spring force of the spring

102 on the valve spool 101. An operating medium pressure in the second control chamber 105 is provided to move the valve spool 101 against the operating medium pressure in the first control chamber 103 and thus from the second valve position. The operating medium pressure in the second control chamber 105 is for the displacement of the valve spool 101 provided in the first valve position. In principle, the second control chamber 105 can also be dispensed with.

To provide a switching force acting in the first valve position, the emptying slide 100 has a second control surface 15, which is assigned to the second control chamber 105. The second control surface 1 15 is provided for providing a dependent of the operating medium pressure in the second control chamber 105 switching force in the first valve position. The prevailing in the second control chamber 105 operating medium pressure acts on the second control surface 1 15. The valve spool 101 has the second control surface 15 on. The control surface 104 associated with the first control chamber 103 and the control surface 15 associated with the second control chamber 105 counteract the valve spool 101 in opposite directions. The first control surface 104 and the second control surface 115 are oriented opposite to one another with regard to the switching direction. The spring 102 is arranged in the second control chamber 105.

For supplying the first control chamber 103 with an operating medium pressure, the first control chamber 103 of the emptying slide 100 is hydraulically connected to the parking slide valve 91. The parking lock slide 91 is provided to supply the diverted operating medium pressure to the first control chamber 103 in the first valve position. In the first valve position of the parking slide valve 91 prevails in the first control chamber 103 of the branched off from the parking slide valve 91 operating medium pressure. In its second valve position, the parking lock slide 91 is provided to empty the first control chamber 103 of the emptying slide 100. In the second valve position of the parking slide valve 91, the first control chamber 103 is depressurized.

To supply the second control chamber 105 with an operating medium pressure, the second control chamber 105 of the emptying slide 100 is hydraulically connected to the first control chamber 94 of the parking slide valve 91. The second control chamber 105 of the emptying slide 100 is hydraulically connected to the control solenoid valve lubrication pressure 20. By means of the control solenoid valve lubrication pressure 20, the operating medium pressure in the second control chamber 105 of the emptying slide 100 can be adjusted. The parking brake device 68 has a counter-pressure line 107, which connects the second control chamber 105 of the emptying slide 100 hydraulically to the control magnetic-valve lubricating pressure 20. In the second control chamber 105 prevails set by the control solenoid valve lubrication pressure 20 operating medium pressure. The set by the control solenoid valve lubrication pressure 20 operating medium pressure thus acts on the lubricating pressure slide 19, the centrifugal oil valve 45, the parking slide valve 91 and the drain valve 100 as the control pressure. Due to the backpressure line 107 can be increased safety and switching dynamics in normal operation, especially at low temperatures. In principle, the connection of the second control chamber 105 of the emptying slide 100 with the control magnetic valve lubricating pressure 20 can also be dispensed with.

To the diverted from the parking lock slider 91 resources on the

Emptying slide 100 to supply the pressure chamber 76 provided for actuating the parking lock actuator 69, the emptying valve 100 has a pressure chamber 106. The pressure chamber 106 is arranged between the control chambers 103, 105 along a displacement axis of the valve spool 101. The pressure chamber 76 of the actuation unit 69 provided for actuating the parking lock is supplied and emptied via the pressure chamber 106 of the emptying slide 100 with the operating medium branched off from the parking slide valve 91.

The pressure chamber 106 of the emptying spool 00 comprises an actuating port 108, which is hydraulically connected to the pressure chamber 76 of the actuating device 69 provided for actuating the parking brake, a return port 109, which opens into the unpressurized operating fluid reservoir 13, and a supply port 110, which is hydraulically connected to the parking lock slider 91 is connected. The return port 109 is provided for discharging the pressure space 76 of the operating unit 69 provided for operating the parking lock.

The supply port 1 10 is provided to the pressure chamber 106 of the

Emptying slider 100 with the branched off from the parking lock slider 91

Supply resource pressure. The supply port 1 10 is hydraulically connected to the first control chamber 103 of the emptying slide 100. The parking brake device 68 has a connecting line 1 11, which connects the first control chamber 103 and the supply port 1 10 hydraulically to the parking lock slider 91. The connecting line 11 1 connects the first control chamber 103 and the pressure chamber 106 hydraulically with each other.

The actuating port 108 connects the pressure chamber 106 of the discharge valve 00 and the pressure chamber 76 provided for actuating the parking brake

Actuator 69 hydraulically with each other. The parking brake device 68 has a connecting line 12, which connects the pressure chamber 106 of the emptying slide 100 and the pressure chamber 76 of the provided for actuating the parking lock actuator unit 69 hydraulically. In order to provide an additional switching force acting in the second valve position, the emptying slide 100 has a third control surface 14 which is assigned to the pressure chamber 106 provided for the operating medium supply of the actuating unit 69. To form the third control surface 1 14 of the valve spool 101 is designed to limit the pressure chamber 106 stepped. The valve spool 101 has surfaces facing each other which are axially delimiting the pressure chamber 06 and which differ in an efficiency provided for the provision of an axial force oriented parallel to the displacement axis. The surface with the higher efficiency provided for the provision of the axial force oriented parallel to the displacement axis forms the third control surface 14. The efficiency provided for the provision of the axial force oriented parallel to the displacement axis depends, in particular, on an area of the surface and / or on an angular position relative to the displacement axis. In this embodiment, the surface forming the third control surface 14 has a larger area compared to the other surface. In principle, it is conceivable that the surface forming the third control surface 14 and the other surface additionally or alternatively differ in the angular position relative to the displacement axis of the valve slide 101. It is fundamentally conceivable that the surface forming the third control surface 14 and the other surface have the same surface area, wherein the surface forming the third control surface 14 is oriented perpendicular to the displacement axis and the other surface is oriented obliquely to the displacement axis.

The third control surface 1 14 is provided for providing a dependent of the operating medium pressure in the pressure chamber 106 switching force in the second valve position. The prevailing in the pressure chamber 106 operating medium pressure acts on the third control surface 114. The valve spool 101 has the third control surface 1 14 on. The third control surface 1 14 is arranged along the displacement axis of the valve spool 101 between the first control surface 104 and the spring 102. The first control chamber 103 associated control surface 104 and the pressure chamber 106 associated control surface 1 14 act in the same direction on the valve spool 101. The first control surface 104 and the third control surface 1 14 are aligned with respect to the switching direction rectified to each other. The second control chamber 105 associated control surface 1 15 and the pressure chamber 106 associated control surface 1 14 act in opposite directions on the valve spool 101. The second control surface 15 and the third control surface 1 14 are oppositely oriented with respect to the switching direction to each other. The operating medium pressure in the pressure chamber 106 is provided to move the valve spool 101 against the spring 102 and thus from the first valve position. The operating medium pressure in the pressure chamber 106 is provided for displacement of the valve spool 101 in the second valve position. The switching force provided by the third control surface 1 1 is provided to assist the switching force provided by the first control surface 104, whereby the second valve position of the discharge valve 100 can be maintained by small operating pressures diverted from the parking slide valve 91.

The emptying slide 100 is provided to decouple in its first valve position, the third control surface 1 14 of the provision of the switching force and to use in its second valve position, the third control surface 1 14 for providing the switching force. In the first valve position of the emptying slide 100, the third control surface 114 is ineffective. In the second valve position of the emptying slide 100, the third control surface 1 14 is effectively switched.

In its first valve position, the emptying slide 100 connects the third control surface 1 14 hydraulically with the return port 109. In the first valve position of

Emptying slider 100 does not affect the working medium pressure on the third control surface 114. The emptying slide 100 separates in its first valve position, the first control surface 104 and the third control surface 1 14 hydraulically from each other. In its first valve position, the emptying slide 100 binds only the first control surface 104 hydraulically to the parking slide valve 91. In its first valve position, the emptying slide 100 hydraulically separates the third control surface 114 from the supply connection 110. In the first valve position of the emptying slide 100, the operating medium branched off by the parking slide valve 91 switched in its first valve position acts only on the first control surface 104 Circuit of the second valve position of the emptying slide 100 starting from its first valve position takes place only by means of its first control surface 104.

In its second valve position, the emptying gate 100 hydraulically separates the third control surface 14 from the return port 109. In its second valve position, the emptying gate 100 hydraulically connects the third control surface 14 to the supply port 10. The emptying gate 100 connects the first control surface in its second valve position 104 and the third control surface 1 14 hydraulically with each other. In its second valve position, the emptying slide 100 binds the first control surface 104 and the third control surface 114 hydraulically to the parking slide valve 91. In the second In the second valve position of the emptying slide 100, the third control surface 114 supports the first control surface 104 in the provision of the second valve position of the emptying valve 100 Switching force in the second valve position. The provision of the switching force for maintaining the second valve position of the emptying slide 100 is effected by means of the first control surface 104 and by means of the third control surface 14. For switching the second valve position of the emptying slide 100, a larger operating medium pressure is required than to maintain the second valve position of the emptying slide 100.

To interpret the parking lock the parking lock slide 91 is in its first

Valve position brought. In its first valve position, the parking slide valve 91 connects the working pressure line 14 hydraulically with the connecting line 111, whereby the first control chamber 103 of the discharge valve 100 is supplied with the working pressure. The unlocking line 116 is via the parking lock slide 91 to the

Resource reservoir 13 connected. The supply of the pressure chamber 76 of the

Actuator 69 and thus the interpretation of the parking brake is not yet possible. For this purpose, only a first pressure threshold in the connecting line 11 1 and thus in the first control chamber 103 must be exceeded by the working pressure to the

Discharge slider 100 to switch from its first valve position to its second valve position and thereby release the working pressure to the parking brake piston 71. Due to the stepped version of the emptying slide 100 is after the circuit of the

Emptying slide 100 in the second valve position in addition to the first control surface 104 of the emptying slide 100, the third control surface 1 14 of the emptying slide 100 effectively, thereby ensuring that at pressure drop below the first

Pressure threshold of the emptying slide 100 continues to maintain its second valve position. Only when the working pressure is significantly lower than the first pressure threshold can the emptying slide 100 switch back into its first valve position and connect the pressure chamber 76 to the working fluid reservoir 13. A second pressure threshold of the working pressure, below which the emptying slide 100 switches back into the first valve position, is below a minimum working pressure that is actuated during driving, so that an unintentional pressure relief in the pressure chamber 76 and thus an undesired insertion during operation when the parking lock is designed the parking brake is prevented. At the same time ensures that the switching of the second valve position of the emptying valve 100 and thus the need to leave the parking position, high working pressure but that the parking brake not in the event of a defective control solenoid lubrication pressure 20 when starting the engine 1 1 while the parking brake engaged is designed unintentionally. This makes it possible to dispense with a strong design of the spring 102 of the emptying slide 100, which can be prevented that during operation at low working pressures of the emptying valve 100 unintentionally switches to the first valve position. In particular, it can be prevented that the actuating element 72 abuts against the locking element 81, whereby mechanical loads can be reduced.

The second pressure threshold of the working pressure, below which the emptying slide 100 switches back into the first valve position, is higher than the lowest possible, i.a. only in case of emergency, working pressure was on. This ensures that if there is a defect on the

Regelmagnetventil lubricating pressure 20 even at low temperatures and thus tough equipment by a corresponding targeted reduction of the working pressure on this emergency level sufficiently fast engagement of the parking brake is done. Of course, this functionality can also be used by software in normal operation.

To engage the parking brake, the control solenoid valve lubrication pressure 20 is activated. By entering operating means in the first control chamber 94 of the parking slide valve 91. By exceeding a pressure threshold of the operating medium pressure in the first control chamber 94, the parking slide valve 91 switches to its second valve position and connects the working pressure line 14 with the unlocking line 116

Connection line 111 and the connection line 112 are via the

Parking lock slide 91 and the drain valve 100 connected to the resource reservoir 13, whereby the pressure chamber 76 of the actuator 69 and the control chambers 103, 105 are emptied. Due to the working pressure in the unlocking line 1 16, the locking element 81 is moved to its unlocked position and the

Actuator 69 unlocked, causing the parking brake piston 71 moves due to the spring force of the spring 78 in the switching direction 75. This will engage the parking brake.

About the back pressure line 98 may, depending on the adjacent

Equipment pressure can be prevented that the parking brake slide 91 switches to its second valve position. The back pressure line 98 is useful, for example, when the operating medium pressure in the first control chamber 94 of the parking brake slide 91 is to be used in the overall control, without unintentionally the

Park lock slide 91 to switch. The parking brake device 68 is a redundant system, which can be realized that the single-fault parking brake can always be safely inserted and / or whereby unintentional disengagement of the parking brake can be prevented. In addition, multiple redundant can be ensured that during the

Driving the parking brake is inadvertently inserted.

By third control surface 1 14, the switching back of the emptying slide 100 can be realized below a not reached in driving pressure threshold, without reducing the security against unintentional leaving the parking position when starting the engine 1 1. By the first control surface 104 and the third control surface 1 14 is a high operating medium pressure for holding the parking lock and to hold the designed state of the parking brake a much smaller

Equipment pressure required. This can cause a back and forth movement of the

Park Sperrenkolbens 71 within mold closing stops and / or within the form-locking contour 80 while driving prevented and the associated

mechanical stress or even destruction of the locking unit 79 can be avoided. In case of failure, the working pressure on an emergency level below the

Basic working pressure lowered to ensure engagement of the parking brake.

LIST OF REFERENCE NUMBERS

main pump

internal combustion engine

Suction

Resources reservoir

Working pressure line

Work pressure slide

check valve

Control solenoid valve working pressure

Lubrication pressure line

Lubricating pressure slide

Control solenoid valve lubrication pressure

Return line

suction

additional pump

electric motor

Additional pump line

check valve

Additional pump vanes

check valve

Control solenoid valve

Piston-cylinder unit

Piston-cylinder unit Gear shift pressure chamber

management

accumulator

check valve

Fliehölventil

converter inflow

torque converter

section

cover

section

converter runoff

Equipment cooler

smudge

lock-up clutch

Solenoid control valve converter

management

cover

Gearchanging system

Fliehölraum

feed

Fliehölleitung

Gear shift piston

feed

cover

Parking lock device

operating unit

actuating cylinder

Parking lock piston

actuator

Haupterstreckungsnchtung

switching direction

pressure chamber

print area

feather locking unit

Form-fit contour

locking element

feather

Return line

operating unit

control

Parking lock slide

valve slide

feather

control room

Control pressure line

Supply pressure line

Against pressure line

Kugelumschaltventil

discharge slide

valve slide

feather

control room

control surface

control room

pressure chamber

Against pressure line

actuation port

Return connection

supply terminal

connecting line

control surface

unlocking line

magnetic valve

Claims

claims

Parking brake device for a motor vehicle, with at least one

Actuation unit (69), which is provided for actuating a parking brake, and with at least one emptying slide (100), the at least one pressure chamber (106) with at least one of the operating unit (69) connected

Having actuating port (108),

characterized in that

the emptying slide (100) has at least one control surface (114) assigned to the pressure chamber (106), which serves to provide one of a

Operating medium pressure in the pressure chamber (106) dependent switching force is provided.

Parking brake device according to claim 1,

characterized in that

the emptying slide (100) is provided for decoupling the control surface (114) associated with the pressure chamber (106) from the provision of the switching force in a first valve position and the control surface (114) associated with the pressure chamber (106) for providing the second Use switching power.

3. parking brake device according to claim 1 or 2,

characterized in that

the pressure chamber (106) has at least one return port (109) and the emptying slide (100) is provided to connect in a first valve position the control surface (114) associated with the pressure chamber (106) to the return port (109) and in a second valve position to separate the control surface (114) associated with the pressure chamber (106) from the return port (109). Parking brake device according to one of the preceding claims,

marked by

at least one parking slide (91), which is intended to a

Distribute operating medium pressure for the actuator unit (69), wherein the

Pressure chamber (106) has at least one supply port (10) which is connected to the branched slide valve (91) for supplying the pressure chamber (106) with the branched operating medium pressure, and the emptying slide (100) is provided, in a first valve position, the pressure chamber (106) associated control surface (1 14) from the supply connection (1 10) to separate and in a second valve position the pressure chamber (106) associated control surface (1 14) to connect to the supply terminal (110).

Parking brake device according to one of the preceding claims,

characterized in that

the emptying slide (100) at least one control chamber (103) and a the

Control space (103) associated control surface (104), which is to provide a dependent of a resource pressure in the control room (103)

Shifting force is provided, wherein the control chamber (103) associated

Control surface (104) and the pressure chamber (106) associated control surface (114) are rectified with respect to a switching direction oriented to each other.

Parking brake device according to claim 5,

characterized in that

the emptying slide (100) is provided in a first valve position to separate the control surface (104) associated with the control chamber (103) and the control surface (1 14) associated with the pressure chamber (106) and in a second valve position which controls the control chamber (103 ) associated control surface (104) and the pressure chamber (106) associated control surface (1 14) to each other.

7. parking brake device according to claim 5 or 6,

marked by

at least one parking slide (91), which is intended to a

Distribute operating medium pressure for the actuator unit (69), wherein the

Emptying slide (100) is provided, in a first valve position, only the control space (103) associated control surface (104) to the

Park lock slide (91) connect and in a second valve position to the control chamber (103) associated control surface (104) and the pressure chamber (106) associated control surface (1 14) to the parking brake slide (91).

8. parking brake device according to one of the preceding claims,

characterized in that

the emptying slide (100) at least one control chamber (105) and a

Control space (105) associated control surface (1 5), which is to provide one of a resource pressure in the control room (105) dependent

Shifting force is provided, wherein the control chamber (105) associated

Control surface (1 15) and the pressure chamber (106) associated control surface (1 14) with respect to a switching direction are oriented opposite to each other.

9. parking brake device according to one of the preceding claims,

marked by

a locking unit (79) provided for locking the actuating unit (69) and at least one parking lock slide (91) which is provided to divert a working medium pressure for the actuating unit (69) in a first valve position and a working medium pressure for the locking unit (2) in a second valve position ( 79).

10. parking brake device according to claim 9,

characterized in that

the locking unit (79) has an operating-technical control (89) and a control device (89) acting in parallel to the operating medium

electromagnetic drive (90).