Vehicle with a drivetrain having a multiple clutch device

[Technical Field]

0001The invention relates to several main aspects generally a so-called Multiple clutch device, if appropriate double clutch device, for Arrangement in a motor vehicle drive train between a drive unit and a transmission, wherein the coupling means includes a first Transmission input shaft assigned first clutch assembly and a second transmission input shaft assigned second clutch arrangement for Torque transfer between the drive unit and the transmission comprises, wherein the clutch assemblies as multi-plate clutch assemblies are carried out, which an operating fluid, in particular a cooling oil, for operation under the action of the operating fluid (in particular for a wet-running operation) can be supplied. It is in this connection in particular (but not exclusively) to such a coupling device thought, in which the multi-plate clutch arrangements hydraulically hydraulic means in the coupling device integrated are slave cylinders operable.

[State of the art]

0002Such coupling devices are in various patent applications proposed by the applicant, it is for example in the DE 100 04 179 A1 reference, the disclosure by reference in the present application is fully involved.

0003The invention relates to this main aspect, further comprising a drive train which a drive unit and a gear (possibly powershift) having a first Transmission input shaft and a second transmission input shaft and a having coupling device of the type mentioned, and such a one Powertrain comprehensive motor vehicle. It is in this connection particularly contemplated that the preferably as powershift running gear an actuator assembly and the actuator assembly -addressing control means is associated with the under their mediation first and second transmission input shaft assigned gears input and are interpretations.

0004To wear or burning of the sipes (especially to prevent friction disks), the lubrication / cooling of the fins is by an operating fluid (in particular cooling oil) required. regularly for Such applications used oils have at operating temperature (ca. 90 ° C) a low viscosity (low viscosity), so that with opened Clutch assemblies (unpressurized hydraulic actuating cylinders in the case a hydraulically actuated clutch assembly of the NORMALLY-OPEN-type) the drag torque caused by the lamellae between the contained oil caused, are relatively low (for example, less than 2 Nm). However, if the oil temperature is very low (about significantly smaller as 0 ° C), as the example as a result of a nightly soaks Motor vehicle can occur in winter, results in a dramatic increase Toughness (viscosity) of the oil, and it can then very high drag torques occur (up to values ​​greater than 25 Nm). In addition to the drag torques can breakout or Loslösmomente of up to 50 Nm due to each adherent (together adhesive) lamellae occur to The start of the driving operation but would only be applied once to each other adherent (together adhesive) fins to disengage. After This loosening of the discs results then but still the drag torques on until the resistance (viscosity) of the oil through the heating of the motor and the introduction of heat (frictional energy) decreases in the clutch assemblies.

0005As a result of these high towing or stringing bonding moments can Engaging a gear to be virtually impossible, because the synchronizers the gearbox is generally not for overcoming such high moments are designed. Typical are the synchronizers designed for 5 Nm torque in the order. Can not courses inserted or can not be switched, as is a driving operation with the Vehicle is not possible.

0006In the German patent applications 101 28 856.5 (AT 15.06.2001; Title: "Coupling system with at least one multi-plate clutch arrangement, Powertrain with the clutch system and warm-up method thereof ") and 101 18 756.4 (AT 17.04.2001; Title: "coupling system") were different made suggestions that at least the above problems can relieve. The featured in these applications Problem solutions and solutions can also in connection with the here in Below we made proposals be advantageously applied. Of the Disclosure of the above two applications is Reference into the disclosure of the present application integrated.

[Summary of the Invention]

0007The present invention aims, the above-mentioned to solve problems, or at least mitigate, in particular better to make them manageable.

0008In normal driving conditions without strong acceleration or without starting with large load (eg starting with a trailer) heats up the working fluid (Cooling oil) only relatively slowly as a rule. This means, that is also occurring in the clutch assemblies Reduce drag torques only comparatively slowly. It is therefore conceivable that the drag torques only after two to three minutes reach values ​​or a normal synchronizing without overloading Allow damage to the synchronizers. Advantageous for reducing the Warm-up period is definitely the quantity of operating fluid (cooling oil quantity) so small as to maintain essential. In this context can in the German patent application no. 101 18 756.4 (AT 17.04.2001) suggested action and configurations of a Coupling system advantageously be applied. Taken into account is also that the trailing torque highly currently supplied from the Operating fluid quantity (amount of cooling oil) increases. This suggests only minor supplying working fluid amounts. On the other hand has the necessary Cooling are provided. It is a compromise between the necessary Look for and find cooling and lowest possible drag torques.

0009One way to shorten the heating time is the specific Warming by introducing power loss in the coupling device, eg by simultaneously pressing both clutch assemblies, so that a Part of the power of the drive unit (motor power) in the coupling means is converted into heat. It is this, in the German patent application no. reference 101 28 856.5 (AT 15.06.2001), the disclosure in the Disclosure the present application is incorporated.

0010Another possibility for reducing the drag torque is that the supply of operating fluid is then reduced or switched off completely, if no cooling or lubrication of the blades is needed. From this directly results in a reduction of the drag torques, as these by caused located between the blades operating fluid (oil cooling) will. It is according to one aspect for a motor vehicle, comprising a Drive train, comprising: a drive unit, a transmission with a first Transmission input shaft and a second transmission input shaft and a Clutch means having a first clutch arrangement associated with the first Transmission input shaft is assigned, and a second clutch arrangement, the second transmission input shaft is assigned for transmitting torque between the drive unit and the transmission, the clutch assemblies are designed as multi-plate clutch assemblies, which an operating fluid, in particular a cooling oil, for operation under Action of the working fluid through the intermediary of a pump assembly can be supplied, especially proposed that the pump assembly or a Flusseinstelleinrichtung is controlled by a control device to a instantaneous operating fluid flow to the multi-plate clutch assemblies set, and that the control means is adapted, in dependence from a current supply needs for operating medium to at least one the clutch assemblies to increase the operating fluid flow and to Decrease, such that the control device to supply with lower demand reduced operating fluid flow or interrupts and larger Supply needs the operating fluid flow increases.

0011For current drive unit is the centrifugal force, the operating fluid from the fins of the non-actuated clutch assembly thrown. From this results in a significant reduction in drag torque. It is imaginable, that the drag torques are reduced so far by this measure, that even the engagement of gears on the respective Transmission input shaft. So one could think, for a Starting, for example, in 2nd gear which is not used for starting Clutch arrangement which is assigned to the still reverse gear engaged, freizuschleudern quickly and thus for switching to the next forward gear prepare. This switching can then usually normal and without carried excessive burden of synchronizers of the transmission and is then not necessary, the driver safety reasons a Speed ​​limit (because of the still engaged reverse gear) unreasonable.

0012A further development it is proposed that the control device to Zuführbedarf with a view to occurring on the clutch assembly dissipation or / and to a lubrication needs to the plates of the clutch assembly certainly. This is always sufficient cooling and lubrication worried.

0013According to another aspect is for a motor vehicle, comprising a Drive train, comprising: a drive unit, a transmission with a first Transmission input shaft and a second transmission input shaft and a Clutch means having a first clutch arrangement associated with the first Transmission input shaft is assigned, and a second clutch arrangement, the second transmission input shaft is assigned for transmitting torque between the drive unit and the transmission, wherein the Clutch arrangements are embodied as multi-plate clutch assemblies, which an operating fluid, in particular a cooling oil, for operation under Action of the working fluid through the intermediary of a pump assembly can be supplied, provided that the pump arrangement or the Flusseinstelleinrichtung and / or a hydraulic associated actuating device for the clutch assemblies Pump assembly is operable in a circulation mode in which by Circulating operating fluid independent of a supply demand Operating medium to the clutch assemblies or whatever the Actuating the clutch means heat energy in the operating medium is entered. This invention proposal stems from the fact that by circulating liquid energy is introduced into this, so that the liquid is heated. After the proposed invention it is thus provided that to heat the operating fluid therethrough and thus the drag torques thereby reducing that the operating fluid by operating the respective pump assembly or Flusseinstelleinrichtung in recirculation mode is circulated and heated thereby. Preferably, a bypass is unlockable, to the operating medium to the clutch assemblies past circulate to can, so that does not increase the circulation of even the drag torques will.

0014A further development it is proposed that a controller adapted is a indizierendes an upcoming start of the automotive event then initiate the circulating to address and in reaction. For example, when using an electric cooling oil / pressure oil pump the invention "warm-up" already be initiated if the driver remotely opens the vehicle and / or the driver's door opens. One can to conserve electrical energy (around the ensure starting an engine) also provide that the is circulating operation initiated only when the engine is running.

0015Generally it is proposed that a / the control means adapted to is to automatically initiate the circulation mode if at least one does not meet condition-positive and / or at least one negative condition is satisfied. It is also generally suggested that a / the control means is adapted to terminate the automatic circulation mode when satisfies at least one positive condition or / and at least one negative condition is not satisfied.

0016Depending on the design of the motor vehicle with regard to the low temperature operating it is conceivable that a driving off will only be allowed if the Operating fluid (oil) a sufficiently high temperature or such a reaches viscosity that a proper switching is possible. It will particularly proposed that a / the control unit is adapted starting of the drive unit in response to a current release viscosity state of the working medium and to terminate.

0017This proposal is of general interest, thus refers not only to the warming up of the working fluid by circulation, but especially All other options for heating the working fluid before Journey.

0018According to a third aspect of the invention, therefore, for a motor vehicle, comprising a drivetrain, which has: a drive unit, a transmission with a first transmission input shaft and a second transmission input shaft and a clutch device having a first clutch arrangement which the first transmission input shaft is assigned, and a second Clutch arrangement which is assigned to the second gearbox input shaft, for Torque transfer between the drive unit and the transmission, running the clutch assemblies as multi-plate clutch assemblies are, where an operating fluid, in particular cooling oil, for operation under the action of the working fluid through the intermediary of a Pump arrangement can be supplied, proposed that a control device is adapted to starting of the drive unit in response to a release instantaneous viscosity state of the working medium and lock.

0019Generally, the heating of the operating fluid appears through appropriate Operation of the coupling device of particular interest. For this purpose, be provided that a / the control means is adapted, by means of a preferably hydraulic actuator which actuate clutch assemblies and in a warm-up mode at least one, preferably both clutch assembly to operate with slip. It will again to the disclosure of German patent application no. 101 28 856.5 (AT 15.06.2001) referred.

0020In this connection it is particularly contemplated that the Control means is adapted to the at least one clutch arrangement with slip when the vehicle against a braking a to let braking device work and / or at least one operate clutch assembly in a moving vehicle with slip. On Loop Let a clutch assembly or clutch assemblies in gear against a braking device should preferably in a high gear take place, since a relatively small drive torque at the Wheels acts and the braking device so that a relatively small moment (Braking torque) must apply in order to keep the vehicle or a favored resultant driving torque set.

0021In connection with all the invention proposals as well as independent thereof, it is useful, preparatory and support measures provide to the parking of the vehicle and / or the gear engagement so prepare that the drag torque problem is at least alleviated, and order so that by targeting the breakaway of the slats, promote or assist overcoming the adhesion torque.

0022Thus, for the preparation of the linkage specifically proposed that a Pump assembly or by a Flusseinstelleinrichtung / controller can be controlled to an instantaneous operating fluid flow to the adjust multi-plate clutch assemblies, and that the control device is designed to prepare the throw-off of the motor vehicle or when parking the vehicle with disengaged clutch assemblies for a predetermined time interval an excessive operating fluid flow adjust to the plates of the clutch assemblies by means of the Operating fluid flow to push apart. After this Proposed development is provided, the coolant flow, in particular cooling oil flow to the clutch arrangements for cooling thereof temporarily greatly raise to at by this current the slats disengaged clutch assembly push apart. This measure may advantageous both when parking the motor vehicle with inlaid corridors as applied when parking the motor vehicle with designed courses be and is of general interest.

0023Accordingly, according to a further independent aspect (4 main aspect) of the invention for a motor vehicle comprising a drive train which comprising: a drive unit, a transmission with a first transmission input shaft and a second transmission input shaft and a clutch means having a first clutch arrangement associated with the first transmission input shaft is associated and a second clutch arrangement which the second transmission input shaft is assigned, for torque transmission between the drive unit and the transmission, the clutch assemblies are designed as multi-plate clutch assemblies, which an operating fluid, in particular a cooling oil, for operation under Action of the working fluid through the intermediary of a pump assembly can be supplied, provided that the pump assembly or is flow adjustment assembly controlled by a control device to a instantaneous operating fluid flow to the multi-plate clutch assemblies set, and that the control device is adapted to a upcoming shutdown of the motor vehicle or parking the to identify the motor vehicle and in preparation of the linkage or the Stopping at the disengaged clutch assemblies for a given Time interval set an excessive operating fluid flow to the Discs of the clutch assemblies by means of the operating fluid flow apart to press.

0024Preferably, the control means is adapted, the excessive Operating fluid flow as required, then adjust if at least one does not meet condition-positive and / or at least one negative condition is satisfied.

0025A further advantageous measure is, before stopping the vehicle the to bring the drive unit briefly relatively high speeds (Eg> 2000U / min) by the resulting increased centrifugal forces Operating fluid (cooling oil) to throw out the clutch assemblies. It is specifically proposed that a / the control means adapted to is to prepare the throw-off of the motor vehicle and / or when parking of the motor vehicle for a predetermined time interval when disengaged Clutch assemblies, the drive unit at an opposite one operate idle speed significantly increased speed in order to Centrifugal force operating fluid from the plates of the clutch assemblies to remove.

0026This proposal is both in connection with a parking the Motor vehicle with inlaid courses as well as in connection with a The vehicle is parked with designed courses advantageous and also of General Interest.

0027Accordingly, in a further aspect (5th main aspect) of the invention for a motor vehicle, comprising a drivetrain, comprising: a Drive unit, a transmission with a first transmission input shaft and a second transmission input shaft and a clutch means having a first Clutch arrangement which is assigned to the first transmission input shaft, and a second clutch arrangement associated with the second transmission input shaft is associated, for transmitting torque between the drive unit and the Transmission, the clutch assemblies as a multi-disk clutch assemblies are carried out, where a working fluid, in particular a cooling oil, for operation under the action of the Operating fluid through the intermediary of a pump assembly can be fed, suggested that one of the drive unit control device associated is adapted to an upcoming parking the motor vehicle or recognize parking the motor vehicle, and in preparation of the linkage or when parking for a predetermined time interval in the disengaged Clutch assemblies, the drive unit at an opposite one operate idle speed significantly increased speed in order to Centrifugal force operating fluid from the plates of the clutch assemblies to remove.

0028can for a particularly effective free spin of the clutch assemblies the control means advantageously be adapted to only the supply of interrupting operation fluid to the clutch assemblies and then for the predetermined time interval, the drive unit in relation to the Idle speed significantly increased speed to operate.

0029Further, the control means may advantageously be designed to have the Drive unit as needed then with respect to the idle speed to operate significantly increased rotational speed if at least one positive condition is satisfied and / or at least not met one negative condition.

0030To prepare the gear engagement or facilitate gear engagement is suggested that a / the control unit is adapted to Preparing an insertion of at least one gear ratio and / or the Inserting the at least one gear ratio for a given Time interval at least a disengaged clutch assembly and / or at most a transmission gear, the drive unit at a compared to an idle speed; significantly increased speed to by centrifugal force operating fluid from the plates of remove clutch assemblies. Thus, after the engine starts to Support gear engagement when no gear is engaged or has been, the Engine speed to be increased to the to the working fluid (cooling oil) thus using increased centrifugal force to the disk set or the freizuschleudern disk sets, thereby reducing the drag torque, so that the gear engagement is facilitated. This invention is also proposed of general interest.

0031Accordingly, in a further aspect (6th main aspect) of the invention for a motor vehicle, comprising a drivetrain, comprising: a Drive unit, a transmission with a first transmission input shaft and a second transmission input shaft and a clutch means having a first Clutch arrangement which is assigned to the first transmission input shaft, and a second clutch arrangement associated with the second transmission input shaft is associated, for transmitting torque between the drive unit and the Transmission, the clutch assemblies as a multi-disk clutch assemblies are carried out, where a working fluid, in particular a cooling oil, for operation under the action of the Operating fluid through the intermediary of a pump assembly can be fed, suggested that one of the drive unit control device associated adapted an upcoming insertion of at least one Transmission gear or engagement of the at least one transmission gear to recognize and in preparation for the insertion and / or when inserting a predetermined time interval at least a disengaged clutch assembly and / or at most a transmission gear, the drive unit when compared to an idle speed significantly increased to operate speed to by centrifugal force operating fluid from the to remove fins of the clutch assemblies.

0032It is especially thought the drive unit when disengaged Clutch assemblies and / or without gear used in the against the idle speed to operate significantly increased speed.

0033A further development it is proposed that the control device adapted is, until the supply of operating fluid to the clutch assemblies to pause and then for the predetermined time interval, the drive unit at the opposite of the idle speed significantly increased speed to operate. One can interpret the controller advantageous for the drive unit if necessary, then with respect to the idle speed significantly increased speed to operate if at least one positive condition met and / or at least one negative condition is not fulfilled.

0034To support the slats of the Losbrechens is proposed that a / the control means is adapted to prepare for the insertion a transmission gear with a stationary and / or running drive unit means a preferably hydraulic actuator which Clutch assemblies at least once, preferably several times sequentially actuate the inputs and disengagement order by mechanical Bracing of clutch assemblies and / or displacement of the Lamellar detachment of fins from each other, of the intermediary exemplary operating fluid to each other to achieve or at least to support. It has namely been found that at about hydraulically actuated clutch assemblies with integrated in the coupling device hydraulic slave cylinders by repeatedly pressing the plunger of the two clutch arrangements the clutch assemblies are braced and that slight shifts of the fins occur. The manner of Actuation of the clutch arrangements takes place in connection with the but proposal ultimately irrelevant. The actuation of the clutch arrangements can advantageously be both at a standstill and with the engine running. Even this operation may be sufficient to a breakaway of the slats to to accomplish. This operation can with before starting the engine at a inlaid corridors parked vehicle as well as in a designed with Transitions parked vehicle advantageously be carried out, and further, if necessary as required, after starting the engine. The proposal is also independent of the other aspects of the invention of interest.

0035Accordingly, according to another aspect (the seventh main aspect) of the invention for a motor vehicle, comprising a drivetrain, comprising: a Drive unit, a transmission with a first transmission input shaft and a second transmission input shaft and a clutch means having a first Clutch arrangement which is assigned to the first transmission input shaft, and a second clutch arrangement associated with the second transmission input shaft is associated, for transmitting torque between the drive unit and the Transmission, the clutch assemblies as a multi-disk clutch assemblies are carried out, where a working fluid, in particular a cooling oil, for operation under the action of the Operating fluid through the intermediary of a pump assembly can be fed, wherein the clutch arrangements is assigned a control device which is adapted to the clutch assemblies by means of a preferably to actuate hydraulic actuator, suggested that the Control means is adapted to prepare for the insertion of a Transmission gear for standing and / or running drive unit by means of Actuator coupling assemblies at least once, preferably several times in succession in the input and disengagement to press to mechanical clamping of the clutch assemblies and / or displacement of the slats detaching from each other slat, the adhere to each other through the intermediary of the operating fluid, to achieve or at least to support.

0036The control means may be adapted to the clutch arrangements in the Inputs and disengagement with respect to the release of the lamellae of one another if necessary, then to operate if at least one positive condition fulfilled and / or at least one negative condition is not fulfilled.

0037The mutual loosening of the lamellae may also achieved or at least be encouraged that while playing a drive unit aware vibrations the coupling means are incorporated. For this purpose, specially suggested that a / the control means is adapted by corresponding actuation of the ongoing drive unit to the Coupling means acting rotational irregularities or speed irregularities, particular torsional vibrations in the drive train to produce selectively to a loosening of fins from each other, the under stick placement of operating fluid to each other, to achieve or at least to support. It is particularly advantageous if this Speed ​​irregularities, in particular vibrations in the area of Natural frequencies of the clutch assemblies and / or the slats are, as that it were targeted to the mutually adhering slats is acted. This proposed development is also of general Interest.

0038Accordingly, in a further aspect (8 main aspect) of the invention for a motor vehicle, comprising a drivetrain, comprising: a Drive unit, a transmission with a first transmission input shaft and a second transmission input shaft and a clutch means having a first Clutch arrangement which is assigned to the first transmission input shaft, and a second clutch arrangement associated with the second transmission input shaft is associated, for transmitting torque between the drive unit and the Transmission, the clutch assemblies as a multi-disk clutch assemblies are carried out, where a working fluid, in particular a cooling oil, for operation under the action of the Operating fluid through the intermediary of a pump assembly can be fed, suggested that one of the drive unit control device associated is adapted by corresponding control of the running Drive unit to the clutch device acting speed irregularities, particular torsional vibrations in the drive train specifically to produce to a loosening of fins from each other, of the intermediary exemplary operating fluid to each other to achieve or at least to support.

0039The control device may be adapted, responsive to the coupling means acting speed irregularities by means of the drive unit if necessary, then to produce, when at least one positive condition fulfilled and / or at least one negative condition is not fulfilled.

0040In case of running an internal combustion engine drive unit, the Control means adapted to be responsive to the coupling means acting speed irregularities by cylinder disconnections and / or not uniform and / or alternating supply of the cylinder with fuel to produce. The deliberately introduced vibrations can eg by , Can be achieved cylinder disconnections being possible to provide that always off the same or alternatively different cylinders will. Furthermore, the cylinders on each with different amounts Fuel to be supplied to consciously generate rotational irregularities.

0041The invention further relates to a motor vehicle drive train, possibly with a associated control device, for an inventive motor vehicle, wherein the drive train and / or the control device according to at least one Aspect of the invention is constructed as explained above.

0042The invention further relates to a multiple clutch device, in particular The dual clutch device, optionally with an associated control means, for an inventive motor vehicle, wherein the multi-clutch device and / or the control device according to at least one aspect of the invention such as is formed explained above.

0043The invention further relates to a motor vehicle transmission, in particular power shift transmission, optionally with an associated control device, for a inventive motor vehicle, said transmission (possibly dual clutch Or Powershift transmission) and / or the control device according to at least one Aspect is formed as explained above.

0044The invention further relates to a method for operating a motor vehicle and / or a drive train and / or a multiple clutch device or / and a transmission according to the invention, in such a way that problems in Connection with drag torques which at low temperatures in the designed as a multi-plate clutch device coupling device occur, dominated or at least mitigated. The process is preferably as a control method for the control device of a Motor vehicle according to the invention or an invention Automotive powertrain or a multiple clutch device according to the invention or a motor vehicle transmission according to the invention executed.

0045In the following the invention with reference to embodiments is nearer explained, on the one hand different invention proposals after the various perform aspects of the invention directly or by way of example in which the various invention proposals after the various Aspects of the invention by the skilled person by routine Applying its expertise can be implemented (for example, by appropriate programming of a transmission and / or a Coupling means and / or a drive unit of the drive train associated electrical control unit microprocessor based), without nor inventive step required.<dl tsize="12"><dt>Fig. 1</dt><dd>shows in Teilfig. 1a is a schematic, exemplary representation of a Basic structure of a coupling system according to the invention with a wet-running double clutch and in Teilfig. 1 b is a schematic View a motor vehicle drive train of the invention including associated, the drive unit, the dual clutch and a Powershift-addressing controller and associated Actuators.</dd><dt>FIG. 2</dt><dd>shows a first embodiment of a coupling system according to the invention.</dd><dt>Fig. 3</dt><dd>shows the coupling system of Fig. 2 in combination with a associated gear.</dd><dt>Fig.4</dt><dd>shows a possible configuration for a cooling oil circuit Transmission of FIG. 3. </dd><dt>Fig. 5</dt><dd>shows in the Teilfig. 5a) is a diagram showing a typical dependence of the in a multi-disk clutch arrangement occurring drag torque at indicates low temperatures as a function of the differential rotational speed, and in the Teilfig. 5b) is a corresponding diagram showing a typical profile the drag torque at very small differential speeds, including the breakaway specifying in the case of composite adhesive lamellae.</dd><dt>FIG. 6</dt><dd>exemplarily a typical transmission synchronization of Prior art.</dd><dt>FIG. 7</dt><dd>schematically an automated dual clutch transmission including upstream dual clutch.</dd><dt>Fig. 8</dt><dd>shows an example of an inventive switching sequence for a train downshift.</dd></dl>

0046Fig. 1 shows in Teilfig. 1a schematically illustrates a coupling system 200 that a wet dual clutch 202 with a first radially outer clutch arrangement 206 and a second, radially inner clutch assembly 204 having. When the clutch assemblies 204 and 206 is around wet clutch assemblies, for example, wet-running Multi-plate clutch assemblies, each having at least a known per se have a disk set that in the present embodiment are arranged radially one above the other and in each case by an associated Actuating piston integrated within the dual clutch hydraulic be slave cylinder operated. Examples of such dual clutches are z. B. DE 100 04 179 A1 and in other published patent applications or patent applications the applicant discloses.

0047The coupling system 200 comprises two independent pumps, namely, a first pump 208 and second pump 209, which is preferably are each driven by an electric motor 210 and 211th The first pump 208, pressure medium, in particular hydraulic oil, at a comparatively high pressure provides the actuation for Clutch assemblies 204 and 206 of the dual clutch 202 is sufficient. to selectively actuating the clutch assemblies are these, more accurately their hydraulic slave cylinder, with an associated valve 214, 216 connected to the pump 208th The pump sucks pressure medium from a Reservoir of 212th

0048The second pump 209 provides a relatively large volume flow Cooling medium, in particular cooling oil prepared that for cooling the clutch assemblies 204 and 206 is used. The pump 209 sucks the cooling medium, oil if necessary, to from a reservoir 222nd It should be noted that it is not mandatory is that it is the reservoir 222 to a reservoir 212 opposite the separate reservoir is.

0049To bring at low temperatures, the cooling oil operating temperature faster can, is on the discharge side of the pump 208 and on the discharge side the pump 209 a switching valve 230 or 232 is provided. By means of the valves can be unlocked to the reservoir 222, a bypass line to by circulating the working medium or print medium at the Coupling device (dual clutch) 202 by heat in the oil introduce and this heat it. The warm-up period to achieve the Operating in this way can be shortened considerably and it may Accordingly, relatively quickly, a state can be achieved in which the Clutch assemblies 204 and 206 no disturbing drag torques on Ground temperature due to high viscosity (too much resistance) more occur.

0050Teilfig. 1 b shows a motor vehicle drive train of the invention with the Double clutch 202 associated therewith actuating means 234 (For example from that shown in Fig. 2, the control valves 214 and 216 comprehensive nature), an automated manner by means of an actuator 236 actuated powershift 330 runs with two coaxial Transmission input shafts and an application running as a combustion engine Drive unit 238. The above components are directly or through the respectively assigned actuator of an example than ECU and / or which can be designated TCU controller 316 controllable. The Controller 316, which can also be called control unit, can be made of several communicating part controllers exist and receive signals from various sensors and actuators, such as by a shift lever 452, the example, the shift positions P (parking mode) R (reverse mode), N (neutral mode) and D (forward driving mode) comprising, and from a brake pedal 450. A from the control device CONTROLLED braking system of the vehicle is designated in FIG. 1 b with 454, and a controllable by the control device starter is in Fig. 1 b 456 designated.

0051With regard to the dual clutch should still be noted that this For example, one disclosed in DE 100 04 179 A1 constructions may correspond.

0052Fig. 2 shows an embodiment of a coupling system according to the invention the basic structure shown in Fig. 1 in greater detail.

0053According to FIG. 2, the cooling oil of the dual clutch 202 is a heat exchanger 300 is supplied, as it for example in the event of an extended Slippage operation to a noticeable increase in temperature of the oil well in may sump 212th Through the heat exchanger 300 is the sufficient oil temperature on a for cooling the double clutch Temperature level maintained. Since the cooling oil right at lower temperatures can be thick and because of the flow resistance of Heat exchanger 300 at particularly low temperatures not circumstances more sufficient cooling oil would reach the double-clutch or too high could cause oil pressure to damage, is an example below Spring bias stationary bypass valve 302 is provided, which, when the Cooling oil pressure downstream of the oil cooler 300, a predetermined pressure threshold exceeds, and the cooling oil to the oil cooler 300 opens by the double clutch passes.

0054In the embodiment of FIG. 2 is in the clutch actuation pressure oil circuit a pressurized gas cushion having Direction pressure oil storage 304 incorporated, which is loaded by the pump 208 via a check valve 306 and through the valve 214 and the valve 216 to the actuation slave cylinders the two clutch arrangements is connected 204 and 206th Of the Pressure oil storage 304 provides a uniform pressure level, which is particularly in case of forming the pump 208 as a piston pump is appropriate, and allows that a pump with a particularly small for the pump 208 Air flow is sufficient. The per unit of time delivered by the pump 208b oil volume can therefore be smaller than that during a clutch actuation per unit time required pressure oil volume.

0055The pressure oil circuit between the check valve 306 and the valves 214 and 216 is through a pressure relief valve 308 against an excessively high, possibly leading to damage of the pressure oil pressure secured. The by Filling state of the memory 304 specific pressure in this pressure oil circuit is detected by a pressure sensor 310th Further, the discharge sides of the valves 214 and 216, a pressure sensor arrangement, for example, depending on a pressure sensor 311 his or 313 for both valves, assigned to the other side of the valves ruling, acting on the hydraulic slave cylinder hydraulic pressures detected.

0056Another pressure relief valve 312 ensures that the other side of the Valves 214 and 216 ruling, the hydraulic clutch actuator Coupling means acting pressure does not exceed a maximum value, prevent, for example, also damage. About two Check valves 314 and 316 it is achieved that a pressure limiting valve sufficient to lower the operating pressure of the two hydraulic slave cylinders to be monitored.

0057To maintain the good controllability / controllability of the clutch actuation , a respective hydraulic dampers 307 and 309 (for example, comprising a spring-loaded piston, a Metallbalgfeder or the like) parallel to the two hydraulic slave cylinders of the clutch devices be connected 204 and 206th By such Hydraulic dampers are damped pressure peaks in the hydraulic system.

0058In the event that at low temperatures, so a high viscosity of the oil, the pressure of the cooling oil for cooling the clutch is not sufficient, for example because the the pump 209 hydrodynamic pump used no compelling can generate pressure, is in the arrangement of FIG. 2, a valve 315 provided, via which a small volume flow from the pump 208 of the provided pressure oil flow can be diverted to a kind of "emergency cooling" provide the clutch arrangements, if this is necessary. Since the Opening the valve 315 required solubilizing high viscosity of the cooling oil only at low temperatures occurs in which only a small anyway Cooling need exists for the dual clutch, is enough, a relatively small "Notkühlölstrom" from. These "emergency cooling" is also only as long as necessary, until the temperature of the oil, and thus the viscosity of the oil sufficient to produce a to ensure adequate pumping capacity of cooling oil pump 209th instead a valve 315 could also be a so-called diaphragm or throttle or the like may be provided on the constantly a small flow of branched off to the pressure oil flow provided by the pump 208 in the cooling cycle becomes. Is that the cooling oil only when needed branching valve 315 provided, the pump 208 can also be short-term may be in an overload operation be operated in the short period of time sufficient to Heating of the oil to provide sufficient cooling oil. Since it is usually only very short periods is required, the life of the pump 208 is not thereby reduced. To independently of the operating state of the to ensure pump 209, that of the pressurizing pump 208 in the Cooling circuit supplied oil does not flow back into the oil sump 212 can with the Pump 209, a check valve 317 connected in series, in particular the Pump downstream be.

0059Also in the example of FIG. 2, the bypass valve 232 is provided at low be able to adjust temperatures a circulation mode in which the pump 209 the cooling oil circulates in the dual clutch 202 over. Can be the valve even so run that part of the already provided by the pump 209 Cooling oil flow is led to the dual clutch 202 and the other part on the Bypass line is returned to the oil sump 212th Thus, at least one reduced coupling operation or driving operation of the drive train having motor vehicle possible in the recirculation mode.

0060Fig. 2 shows another electronic control unit ECU (reference numeral 316) in response to a respective control variable, the control / regulating valves 214 and 216 is actuated. There may further be provided that the control unit Readings from various sensors such as the pressure sensor 310 and other pressure sensors (including possibly the sensors 311 and 313), and supplied from temperature sensors or temperature sensors gets. thought in particular to one or more temperature sensors indicating the Temperature of the clutch cooling oil circuit (pump 209, cooler 300 or Bypass valve 302, coupler 202, sump 212) detected. On appropriate, arranged for example in the clutch oil sump 212 and the Temperature of the circuit encircling or contained in the sump oil sensor detecting 320 is shown schematically. The electronic Control unit may further related to the time unit volume of the Pump 209 and / or a transmitted flow of the circuit arranged flow adjustment valve (not shown) or control rules, for example, based on the detected by the sensor 320 temperature signal. In this way, the temperature balance of the coupling device 202 and the clutch cooling oil circuit can be influenced. By adjusting the agitation level in the cooling circuit can influence the Cooling rate to be taken in the radiator 300 (larger or Kleiners ÄT the radiator) and it can turbulent flow conditions on the one hand or laminar flow conditions it should be exploited.

0061For completeness, should be pointed out that with 322 representing and 324 designated components in Fig. 2 oil filter. Alternatively or in addition to the oil filter on the discharge side of each pump 208 his or 209 provided. It will be appreciated that the electronic control unit 216 in addition to the tax-control valves 214 and 216 and the valves 232 and 315 situational operated.

0062In order to start the motor vehicle, especially at low ambient temperatures the cooling oil, and thus the coupling device or bring dual clutch 202 to operating temperatures and in particular the Viscosity of the cooling oil quickly reduce the extent that the system fully is functional, an electric oil-heating arrangement, provided be, for example, at least one heating element 326 in the sump 212 and / or at least one in the suction of the pump 209, for example, in the filter 322, integrated heating element 327 has. Also in the intake line the pump 208, for example, in the filter 224, a least be integrated heating element. As heating elements, for example, about 30 mm x 50 mm wide heater board are used, which on its surface have a kind of heating coil and z. B. a heat output of 300 W may submit. Other types of heating elements, for example in the form of Glow plugs for diesel engines, can be used. Another possibility is a Thermal energy storage device, such as a so-called latency memory, provide.

0063By integrating at least one heating element in a respective intake duct the cooling oil pump 209 and / or the pressure oil pump 208 can be specifically that actually pumped oil are heated without forcibly the entire Oil volume has to be heated. Accordingly, electric power saved. Further, it can be ensured that only preheated oil from the pump in question is pumped.

0064Fig. 3 shows the coupling system of Fig. 2 (not all components are shown) in combination with a dual-clutch transmission 330. The preferably automated actuated gearbox 330 may own, compared to the cooling oil circuit of the coupling device 202 separate have Kühlölkreisölauf, for example of the type shown in Fig. 4. A by a motor 211 'driven oil pump 209' sucks cooling oil from a Reservoir (the transmission sump) 212 'on. The delivered cooling oil is normally via a condenser 300 'to be cooled components of the transmission 330 fed. To avoid excessive pressure in the cooling oil circulation in low temperatures is an example pressure actuated bypass valve 302 ' provided that when exceeding a threshold pressure a radiator 300 ' immediate bypass line releases. The gearbox cooling oil circuit corresponds extent the clutch cooling oil circuit according to FIG. 2 and 3. The cooler 300 'with the bypass line, as shown in Fig. 4, between the pump 209 'and the Transmission (possibly automatic transmission) be arranged 330th It is also conceivable that cooler and bypass switching the transmission or gearbox automatic downstream. The gearbox cooling oil circuit, a be associated with temperature sensor 320 ', the temperature of the circulating Cooling oil measures and corresponding measured values, for example, to the electronic Control unit ECU of Fig. 2 yields. According to FIG. 3 and 4, the Temperature sensor 320 'in the transmission sump 212' arranged.

0065By derogation of the above, to Figures 3 and 4 one for the dual clutch and gearbox is also a common or provide situational combinable cooling oil circuit, as in filed on 17.04.2001 German patent application no. 101 18 756.4 has been proposed. The disclosure of this patent application is Reference into the disclosure of the present application included.

0066Instead of the pressure actuated bypass valve 302 in the case of the clutch cooling oil circuit and 302 'in the case of transmission cooling oil circuit, a electric actuated valve, for example, a 3-2-way valve be provided depending on demand or according to a thermal management strategy (About the targeted achieve and maintain a desired operating temperature) a radiator to release 300 immediate bypass line, so that the cooling oil to the radiator 300, 300 'by the dual clutch 202 and is guided to be cooled transmission components, and these Bypass line to lock again.

0067The dual clutch 202 can advantageously after starting of the motor vehicle, For example, in the case of low ambient temperatures, with defined Slip operate to the cooling oil as quickly as possible to Operating warm. The warming of the cooling oil is carried out by the Slip operation occurs on the fins friction. To an overheating of the avoid relevant plate assembly or the dual clutch and the to achieve desired heating of the cooling oil as quickly as possible, should constantly during slippage operation an example of the pump 209 provisioned flow of cooling oil flowing. For further details of such Slip operation, both at a standstill and when the vehicle can take place, is on the content of the German filed on 15.06.2001 Patent application no. 101 28 856.5 referenced. The disclosure of this German patent application is fully incorporated by reference into the Disclosure of the present application included.

0068The particularly at low ambient temperatures in an approximately outdoors parked motor vehicle occurring high viscosity of a used Cooling oil may well cause significant problems. Through the at low Temperatures (about oil temperatures less than 0 ° C) occurring increased Viscosity of oil can in the multi-plate clutch assemblies very high Drag torques occur (up to values ​​greater than 25 Nm) over at Operating temperature (about 90 ° C) occurring drag torques example less than 2 Nm. Further, due to through between the lamellae fill Oil together adhesive lamellae breakaway or Loslösmomente occur until more than 50 Nm. In consequence of the high towing or breakaway torques can be practically impossible an engagement of a gear, because conventional Synchronizers of the transmission not for overcoming such high moments are designed. Can not insert transitions or not switch, it is not possible a movement of the motor vehicle.

0069FIG. 5a illustrates a typical exemplary course of or at low Temperatures in the coupling device occurring drag torque on Due befindlichem between the slats cooling oil correspondingly high Viscosity as a function of the differential speed between the input side and Än Output side of the respective clutch arrangement. Fig. 5b shows the in low temperatures occurring breakaway due to together adhesive lamellae and the transition to the drag torque according FIG. 5a. For further details refer to the article "drag torques on wet-running Immersed brakes "by N. Holzer and D. Frey, Friedrichshafen, as well as Matthes, Heidelberg, in VDI REPORTS 1323, pages 469-489 due to a meeting VDI Society for Development, Design and Marketing on 03 and 04.03.1997 in Fulda "couplings in drive systems '97" referenced.

0070Fig. 6 shows an example of a conventional single-cone to Synchroniserung the system Borg Warner (ZF) with a needle bearing idler gear A, a Clutch body B with shift gearing and friction cone, a Main function support - synchronizer ring C with counter-cone and serration, a synchro-D with internal gearing for the mold flux with a Transmission shaft and outer teeth of the shifting sleeve, a compression spring E, a ball pin F, a pressure piece G and H with a shift sleeve Claws internal gearing. If you tried, when the motor vehicle and not the engine is running to select a gear, so it may happen that the shifting the engine fails because the selector teeth of Coupling body of the respective Transitional Council with the tooth flanks of the associated Mating gear of the gearshift sleeve of the synchronizer coincide, so that the Teeth can not come into driving engagement. Inserting a Gear is thus only possible when the selector teeth of the Coupling body strikes the interdental spaces of the associated mating gear. Thus it is in conventional design of the associated actuator no real solution if you should remember to avoid Insertion problem at low temperatures due not to overcome the drag torques designed Synchronsiereinrichtungen a starting gear when the motor vehicle is in the state not yet running drive unit insert.

0071In Fig. 7 a dual clutch transmission 330 is schematically illustrated that seven speeds, namely six forward gears G1, G2, G3, G4, G5 and G6 and a reverse gear R has. The forward gears are each a pair of gears, consisting of a drive gear 400-1, 400-2, 400-3, 400-4, 400-5 and 400-6 and an output gear 402-1, 402-2, 402-3, 402-4, 402-5 and 402-6 associated. The reverse gear R has, in addition to a drive wheel 400-R and a Driven wheel 402-R, a direction of rotation reversal forming intermediate 404, the meshes with the drive gear 400-R and the output gear 402-R. The corridors G2, G4 and G6 associated drive wheels are rotationally fixed to a radially outer transmission input shaft 406 is connected and the gears G1, G3, G5 and R associated drive wheels are rotationally fixed to a radially inner transmission input shaft 408 connected. The respective driven gears are rotatably supported on mounted a transmission output shaft 410 and with this to the circuit Courses via associated switching and synchronizing devices 412a, 412b, 412c and 412d rotatably connected. The switching and Synchronsiervorrichtungen 412a, 412c and 412d are double-sided effectively formed, that is, by these respectively alternatively one of two gears can be shifted, in the case of Synchronizing 412a of the first forward gear G1 or Reverse gear R, in the case of the synchronizing device 412c of the third Forward gear G3 or the fifth forward gear G5 and in the case of Synchronsiervorrichtung 412d of the fourth forward gear G4 or sixth Forward gear G6. The synchronizing device 412b, however, is only one side effectively designed and used for switching only the second forward gear G2.

0072As can be seen from the schematic figure or mention are the Transmission input shafts 406 and 408 coaxially arranged to each other, and are the odd-numbered gears G1, G3 and G5 and the reverse gear R of the centrally disposed transmission input shaft 408 and the even-numbered gears G2, G4 and G6 of the form of a hollow shaft gearbox input shaft 406 assigned. The two input shafts are each provided with only one of the Clutch assemblies 204 and 206 in connection, for example the Transmission input shaft 406 to the output side of the clutch assembly 206 and the transmission input shaft 208 to the output side of the Clutch assembly 204. The input side of the two Clutch assemblies are each connected to the output shaft of the drive unit, For example, an internal combustion engine, in conjunction.

0073During normal driving operation of one of the transmission ratios is engaged and which this clutch arrangement assigned closed. At a Switching occurs first, a target gear, for example, the next higher or next lower forward gear, connected and preferably the at Intersection known circuit in which the driving torque from the a is shifted to the other transmission input shaft to a provide tractive force interruption-free switching.

0074In the illustrated embodiment, the dual-clutch transmission is 330 as automatic transmission formed. For this purpose, the switching and Synchronizing 412a to 412d jewiels an example electromotive Switching actuator 414a, 414b, 414c associated or 414d, which on the respective switching and synchronizing effect, for example by a non-positive and / or positive operating link. By Switching actuators, the switching and synchronizing in axial moving direction and to be entrusted with restoring forces, as shown by the Double arrows indicated. At the driven wheels and the switching and Synchronizers are driver formations 416 and 418 schematically shown that the coupling of the respective driven wheel with the Transmission output shaft 410 come into mutual engagement.

0075The switch actuators are associated with the control lines Controller 316 is connected and controlled by them. A speed the transmission output shaft and the transmission output shaft 410, by a detected speed sensor 420th It may furthermore a respective the two Getriebeingangswellen assigned and detected whose speed Speed ​​sensors 422 and 424 may be provided, so that the control device 316 optionally receives information on all three speeds. Another alternative or additionally be provided possibility is that the speed of the Output shaft of the drive unit by a control device with associated speed sensor is detected.

0076To facilitate the insertion of gears at one with designed courses parked motor vehicle, the actuation connections manufacturing, For example, in the kind of shift forks exported connection and Actuators between the switching and synchronizing and each switching actuator designed to be elastic, for example, a respective Federabschnit 430. If when the motor vehicle and not the engine is running by a corresponding command from the control means 316 a switching actuator, for example, the contact module 414, in the sense of actuated engagement of the first gear or reverse gear, then either immediately inserted the transition, provided that the driver formations of the relevant Driven wheel and the associated entrainment formations of the respective contact switching and synchronizing in mutual engagement (So, for example, the teeth of one gear to the Interdental spaces of the other teeth meet), or the transition will not inserted, if the so-called driver formations not in mutual can contact engagement.

0077Is such an intervention is not possible (because the teeth of a Teeth on the teeth of the other toothing meet), as then the Power storage use spring storage 430 tensioned. If now the starter at open clutches actuated, is deeper under the condition Temperatures, so the occurrence of breakout and / or drag torques in the clutch arrangements, the clutch- or motor side gears given a rotational movement, because the drive train due to the breakaway or Drag torques not completely in spite of open clutch assemblies from Motor is disconnected. The gears on the transmission output side are, however, as a parking brake is engaged and / or the vehicle at unlocked Parking lock is. It is thus a relative rotational movement between the Output gears on the one hand and the associated switching and Synchronizers, it will entail in a relative rotational position in which the driver formations occur (because the teeth in mutual engagement of a tooth on the tooth spaces of the other tooth to meet). For an engagement of a gear in the case of having designed Transitions parked motor vehicle possible even at low temperatures.

0078Alternatively or additionally, the switching actuators can also be formed for be vergößerte for short periods to normal actuating forces actuating forces apply that in continuous operation the switching and synchronizing would unduly burden, but under special circumstances (such as a high Viscosity of the multi-plate clutch assemblies associated cooling oil on Basic low temperature) advantageously a gear engagement or gear changes enable. A certain reduction of the life of the switchgear and Synchroniservorrichtungen could take necessary into account, since such Situations rarely occur normally. Moreover, the Controller 316 may be configured to the excessive actuation forces only set for short time intervals and under certain conditions, so that in practice, no significant shortening of the life of the switchgear and Synchronizers will occur.

0079The controller 316 may also include an operating mode, in the when switching from an output gear to a target gear to the Target gear assigned transmission input shaft not only by the target gear assigned switching and synchronizing, but also by an other switching and synchronizing provided per se for when switching to the same transmission input shaft assigned to the to act target gear various gear. For example, for Preparation and insertion of the first gear G1 not only the switching and Synchronizing 412a but also the switching and Synchronizing be 412c operated so that these devices together the transmission input shaft 408 of a speed at least approach, which the current vehicle speed taking into account the Getriebübersetzung in the target gear corresponds (in the example, the first course). Conversely, for inserting the third gear G3 or fifth gear G5 also next to the switching and synchronizing the switching and 412c Synchronizer 412 is operated in this sense. The same applies for the Getriebeeingansgwelle 406 gears assigned G2, G4 and G6. It can two switching and synchronizing (412b and 412d) or (412a and 412c) are operated simultaneously in this sense.

0080However, it is to ensure that not accidentally the wrong gear is inserted. This can be avoided by, for example, that the Control device 316 the speed of the respective transmission input shaft and the transmission output shaft 420 (and / or the output shaft of the drive unit) taking into account the gear ratios, particularly the Gear ratio of not next gear, with each other and before reaching the synchronization point of not next gear on the this is not intended gear associated switching and Synchronsiervorrichtung acting actuation forces cancels or at least sufficiently reduced.

0081By at the not intended gear associated switching and Synchronizing friction energy occurring at low temperatures can also Despite occurring in the coupling device 202 drag torques a gear can be engaged or from an output gear to a target gear are switched.

0082The controller 316 is advantageously adapted via the switching actuators simultaneously insert at least two courses. It is particularly thought that a parking brake is realized by on the same transmission input shaft two gears are inserted. These Measure is known per se from DE 199 50 696 A1.

0083but can advantageously also at least one gear on one transmission input shaft and at least one passage on the other transmission input shaft are inserted, wherein preferably at least one forward gear and the reverse gear belonging to the engaged gears. These courses are preferably inserted automatically by the controller, when the motor vehicle is turned off. Should be set off again, it could be that due to low outside temperatures great Drag torques occur in the coupling device so that no gear more may be lodged (unless that the above suggestions implemented are). If, however, as suggested here, the reverse gear on the one Transmission input shaft and at least one forward gear on the other inserted transmission input shaft, then by engaging the one side and Ausgekuppelthalten or disengaging the other clutch arrangement either the forward gear or the reverse gear is activated for starting will. For many situations it will also be sufficient if only one gear, for example the forward gear, is inserted, preferably automatically by the Controller 316th

0084Apart from the aspect of the parking lock it makes perfect also in other Respect sense, to at least one of the transmission input shafts, preferably on two transmission input shafts, to insert a plurality of gears, when the Motor vehicle is parked. This allows namely for starting a Selection of several courses. There are then all the gears are not needed interpreted, for example, all forward gears up to a starting gear and reverse.

0085In order when starting the engine, an uncontrolled movement of the motor vehicle due at least an engaged gear and at low temperatures occurring drag torques or Losreismomente in to avoid the coupling device, is preferably a security functionality the control device 316 is provided. The controller 316 For example, only allow the engine to start if the same the foot brake 450 (see. FIG. 1 b) is operated. Starting or not starting can also dependent on the instantaneous position of the shift lever 452 be made, for example, a start only in parking mode P are allowed.

0086It is also advantageous for safety reasons if the security functionality lifting the parking mode in which, for example, necessarily a Parking lock is activated, and the change in the reverse mode R or the forward driving mode D in spite of such pressure on the pedal 452 only then allows, when at the same time the foot brake 450 is actuated. hereby is prevented from uncontrolled movement of the motor vehicle comes when the parking lock designed or, in the case of not loaded Corridors, a forward-starting gear or reverse gear is engaged. A Another possibility is that the cancellation of the park mode and - in the case of not loaded corridors - engaging a gear with an actuator of the vehicle brake system 454 is positively coupled. Despite not actuated Brake pedal is then automatically ensured that the vehicle brakes be operated in order to avoid an uncontrolled movement of the vehicle.

0087One may provide that on the basis of the coupling device occurring drag torques a vehicle creep is already provided. For this purpose, the control device 316 a corresponding creep functionality exhibit.

0088Preferably, a compensation of the forces acting on the vehicle wheels Clutch drag torques to zero or a creep or a Peak hold provided (in the case of a vehicle hill-hold function), namely for example by means of the vehicle braking system and / or by means of a coordinated operation of the two clutch arrangements in the case that, on the one clutch arrangement assigned Transmission input shaft and a forward gear on the other Clutch assembly associated transmission input shaft of the reverse gear is inserted. Generally speaking, can by means of the vehicle brake system or with the appropriate actuation of at least one of Clutch assemblies effective drive torque at the vehicle wheels due to clutch drag torques and / or clutch lamellae detention moments be compensated to zero, or references by the control unit 316, the vehicle braking system 454 and / or the Coupling device 202 and the clutch assembly in question correspondingly drives.

0089Referring again to the state in the following, in which simultaneously a forward gear and simultaneously a reverse gear can be engaged. Preferably, these passages can you drive off and subsequent Driving the motor vehicle to remain engaged, and it can by countervailing Actuating the two clutch arrangements between Forward and are changed to the reverse gear, without an operation of the Transmission needs. As long as the reverse gear is engaged, should be increased by Security functionality of the controller 316 may be ensured that a maximum vehicle speed is not exceeded. But you can also an automatic disengagement of the reverse gear for the event provide that the vehicle speed exceeds a threshold value.

0090The controller 316 may advantageously an active Synchronsiermodus have, in which by corresponding control of the motor (generally the Drive unit) and / or by appropriate actuation of the Clutch assemblies, the speed of the target gear associated transmission input shaft the synchronous ratio of the target gear, at least approximately, preferably the rotational speed of the transmission input shaft to the is brought synchronous ratio of the target gear, and then inserting the Target gear to facilitate or permit. The switching and synchronizing are then spared accordingly, and it needs not necessarily the use of multiple stem and synchronizers at the same time, and there may also on the engagement of a gear taking advantage of a bias of the operating connection between the relevant switching and synchronizing and the associated to dispense switching actuator. A torque interruption while Switching is to take in this active Synchronsiermodus in purchasing.

0091Fig. 8 shows an example of a shifting sequence in a train-downshift, the a return zugkaftunterbrechungsfreies switching enabled without the Dobby and Synchronsiervorrichtungen for synchronization of the target gear associated transmission input shaft excessive friction work be made must, even with large drag torques in the Kupplunsgeinrichtung.

0092The FIG. 8 based on the following assumptions and the following nomenclature reason:

0093Reference is made to the transmission input shafts 1 and 2, couplers 1 and 2 and gears 1 and 2 taken. The transmission input shaft 1, the Transmission input shaft 406 and the gearbox input shaft 2, the its transmission input shaft 408, or vice versa. Accordingly, the Clutch 1 of the clutch assembly 204 and the clutch 2 of Clutch assembly 206 correspond, or vice versa. Run 1 is the Transmission input shaft 1 gear assigned (the starting gear) and transition 2 a transmission input shaft 2 associated gear (the target gear). It is in a train-operating state of a larger, the transmission input shaft 1 associated path 1 to a smaller, the transmission input shaft 2 associated gear 2 connected.

0094When Switching train rear-engine supplies a positive torque to the Gear. This torque is transmitted through the transmission input shaft. 1 The Coupling 1 is connected to the transmission input shaft 1, the coupling 2 is provided with the transmission input shaft 2 is connected. In the initial state, the clutch 1 completely closed and is thus in overpressure. The Clutch 2 is open at the example shown in the initial state. The Transmission input shaft 1 thus rotates in the initial state with the Engine speed. On the transmission input shaft 1, a gear is engaged, so that Power flow between the transmission input shaft 1 and the transmission output shaft is prepared.

0095A preferred five switching phases comprehensive shift sequence is shown in FIG. 8 shown schematically. The phases are shown in Fig. 8 by Arabic numerals 1 to 5 designated in circles and are hereinafter referred to as phases I to V addressed. Possible variants and embodiments of the switching phases are . Shown in dashed lines in FIG. To differentiate the various curves and curved sections are provided with the symbols N_Mo for the engine speed, N_G1 for the rotational speed of the transmission input shaft 1, N_G2 for the speed of the Transmission input shaft 2, M_Mo for the engine torque, M_K1 for the moment Coupling 1 and M_K2 provided for the torque of the clutch. 2 Any difference between the positive longitudinal acceleration (see. lowermost part diagram) of the motor vehicle Resulting, the change in vehicle speed representing additional contribution to the change in speed is in the partial diagram not considered for the speeds. Furthermore, for simplicity was of one (without active intervention in the engine control) over to the Engine speed remains constant engine torque assumed. Of the Shift calculated from the beginning of the shift until the end of phase I Switching Phase V could for example, about 0.5 s to 1 s take.

0096If, notwithstanding the above assumptions made and the representation the graph in Fig. 8, the clutch assembly 2 at the beginning also fully closed, so could this initiating the shift in phase I be fully opened.

0097In Phase II, the clutch torque of clutch 1, M is_K1On the in-phase I valid torque of the engine is lowered. The driving torque of the engine is increased and the clutch 2 is easily engaged, so that now the is motor torque greater than the torque of clutch 1, so that Clutch slippage occurs and the engine speed increases, until the late Phase II a speed greater than the synchronous speed of the target gear 2 is achieved. By the slight engagement of the clutch 2, the transmission input shaft 2 is high speeds, so that the speed of the synchronous speed of the Target gear approaching. At the end of Phase II of the target gear is engaged (transition 2) so associated with the participation of the target gear Synchronsiervorrichtung the transmission, the transmission input shaft 2, Synchronous speed of the target gear is reached and thus to engage the Target gear comes.

0098In Phase III is after reaching the selected engine speed above the speed the transmission input shaft 2, the engine torque back to the original lowered torque in order to prevent a further increase in engine speed. The clutch 1 is slipping, and a selected slip speed between the transmission input shaft 1 and the engine speed is by means of the Coupling 1 is regulated. The clutch 2 is closed controlled. Thereby is a controlled opening of the clutch 1 triggered because the previously selected Slip speed can be kept constant only if the sum of the Moments of the two clutches and the transmission input shafts therefore - through the intermediary of the transmission - to the transmission output shaft is transmitted, constant is equal to the selected engine torque. The coupling 2 takes over more and more engine torque until clutch 1 is fully opened is. The clutch 2 can transmit the entire engine torque is now and not closed on. Instead of a controlled closure of the coupling 2 and a controlled opening of the clutch 1 could also be a controlled provide for opening the coupling 1 and a controlled closing of the clutch. 2

0099In Phase IV is a lowering of the engine torque at the clutch torque the engine speed to the rotational speed of the transmission input shaft 2 pulled down. In Phase V, the clutch II is then completely closed. The clutch 1 can be closed also what to rise speed N_G1 the transmission input shaft 1 to the level of Transmission input shaft 2 leads. The motor torque has been at the shifting sequence according to the diagram already at the end of Phase IV to the original value recycled.

0100In Phase II, is shown yet a variant, according to which the torque of the clutch 1 is not reduced completely to the value of the initial engine torque to an undesirable negative intermediate acceleration process of Vehicle due to the acceleration of the gearbox input shaft 2 to avoid. Furthermore, one can in the engine torque phase V to a value above increase the original value by which the acceleration for the Transmission input shaft 1 needed to compensate acceleration energy.

0101This can be achieved that the entire acceleration course during Coupling procedure monotonically without Zwischenverzögerungs- or intermediate accelerations extends by at any time, the initial Engine torque by means of the transmission input shafts discharged into the transmission and in accordance with the gear ratios in the source and target path for Transmission output shaft is transmitted. is on the transmission output shaft maintains it at all times a substantially constant lasting (Phases I, II, IV, V) or monotone (preferably strictly monotonically, eg linearly) rising (phase III) driving torque.

0102According to a shifting sequence, as suggested in Fig. 8 by way of example, is itself at low temperatures and viscous oil cooling switching back without significant burden of synchronizing possible without on to forego the load shifting without interruption of traction.

0103During an upshift, the target gear the associated transmission input shaft synchronous speed level is under the old canal. Is the target gear associated clutch open so can by means of a separate Braking means and / or due to drag torque of the transmission the speed of the target gear associated transmission input shaft between Zero and the new synchronous speed are. One can then by closing of the target gear clutch associated with the assigned to the target gear bring transmission input shaft to the new synchronous speed to a Gear engagement to permit or facilitate. On the load switching without Interruption of traction need not be dispensed with.

0104The foregoing, in the mastery of the problems associated with Drag torques in the coupling device at low temperatures targeted measures are not necessarily under normal operating conditions longer required. It can therefore be provided that the control device 316 automatically a normal shift and clutch operation with free gear selection releases. For this purpose, the control device of an example, the Temperature of the cooling oil measured temperature sensor, a temperature signal receive and compare this with a threshold. If necessary, may be selected from the measured temperature, the viscosity of the cooling oil to be determined, and this be compared with a predetermined threshold value. The Control means can also be provided for other measured values, if necessary temperature values ​​to be considered for drag torques close temperature, for example, based on a Temperature Models.

0105For the active reduction of the drag torque, the controller 316 may a comprise functionality that serves to pump 209 (see. FIG. 2) so to control that only as much cooling oil is supplied to the clutch assemblies, as currently required, for instance with regard to the Coupling means power loss occurring and / or with respect to a Lubrication required on the fins. If necessary, , the cooling oil flow to the Clutch assemblies be completely interrupted if currently no supply is needed.

0106One can also provide that the controller designed is a only release starting the engine, when the viscosity of the cooling oil a does not exceed the maximum value or the temperature of the cooling oil is not under a critical value. This measure is in particular in the Connection with discussed here measures of interest, a Warming of the cooling oil independently of the running of the engine allow (see. Heaters 322, 324 and the recirculation mode in connection with the valve 232). One can also provide that the parking of the vehicle so is prepared so that when restarting the vehicle in the the drag torques and breakaway coupling device occurring be minimized, and ideally, even largely avoided. Thus, the be adapted control device, an upcoming stopping the to identify the motor vehicle or of the same a soak (the controller can this example to an adjustment of the shift lever 452 in the Position P appeal), and in response thereto when parking after disengagement the clutch arrangements for a certain time an excessive cooling oil pressure set or an excessive cooling oil flow to the clutch assemblies, the discs of the clutch assemblies to push apart, Outer disk and the inner disk thus be separated. this happens preferably fully automatically by a corresponding control of the pump 209 316. by the controller Alternatively or additionally, in Response to the detection of an impending throw-off of the motor vehicle or throw-off even after disengaging the clutch arrangements, the Drive unit are controlled by the controller 316 such that the drive unit for a certain time at a relative to the Idle speed significantly increased speed running so that by Centrifugal force the cooling oil from the plate packs radially outward is thrown. To this end, preferably above the cooling oil flow to the Disk packs interrupted.

0107The operation of the drive unit with disengaged clutch assemblies with one against the idle speed significantly increased speed is also to Preparation of inserting at least one transmission gear advantageous since the Drag torques will be the smaller, the less cooling oil between the blades is. Therefore, the control device 316 is also preferably designed the engagement of a gear or the desire that a gear is to be engaged, to recognize, and the driving unit when disengaged to drive in accordance with clutch assemblies. For example, the Controller 316 to an adjustment of the shift lever 452 in the position R or D appeal and only after the proposed revving Drive unit actually engage the gear in question.

0108It has been found that also by operation of the clutch assemblies even loosening of each adhesive lamellae can be achieved or Solve this can be at least assisted. This beneficial effect is on occurring in the course of clutch actuation mechanical strain of Clutch assemblies and the displacement of the slats in the operation due. The control device 316 is preferably adapted to to address the in-gear desire or the shifting the engine and before engaging the gear or before completion of the loading process, the Clutch assemblies at least once, preferably several times successively Following to operate in the input and disengagement to the issues raised achieve useful effect.

0109It has also been found that acting on the coupling means Speed ​​irregularities, such as torsional vibrations, a dissolving bring together adhering slats or at least support. The Controller 316 is therefore preferably adapted to the Drive unit, in particular the internal combustion engine, to drive in such a way that such speed irregularities during A drive unit. For example, shut down in an internal combustion engine cylinder or Cylinders are supplied with fuel or alternately mixed.

0110It will include measures to control or reduce occurring in a lamellar multi-clutch device Drag torque due to temperature-related increased viscosity or Toughness of the blades supplied in operating working fluid proposed commissioning a motor vehicle or operating to enable the motor vehicle even at low temperatures.