DE102007019241A1 - Controlling dual clutch transmission involves simultaneously engaging starting gear of one of two driving gears of same stage of transmission to activate parking lock function - Google Patents

Abstract

The transmission has first (2) and second (4) stages with starting gears (G1, R) for forward and reverse respectively, first and second groups of driving gears, first and second input shafts connected to first (K1) and second (K2) frictional clutches and a common output shaft. Two gears associated with one of the two stages are engaged simultaneously in a parking lock function. It involves simultaneously engaging a starting gear one of the driving gears of the same stage to activate the parking lock function. An independent claim is also included for a dual clutch transmission.

Description

The The invention relates to a method for controlling an automated Double clutch transmission according to the preamble of claim 1 and a dual-clutch transmission for carrying out the Process.

Double clutch have a first input shaft with a first drive side Friction clutch and gear wheels of a first group of Gears, a second input shaft with a second drive side Friction clutch and gear wheels of a second group of Gears as well as a common output shaft. they draw characterized by a design-related possibility for traction interruption-free Shift to another gear, each with a fixed gear ratio out. This is made possible by the fact that the torque a drive motor via the two separately switchable Friction clutches either on the two, often coaxial arranged input shafts can be transmitted.

The called input shafts each carry gears different Gears, where the gears usually alternately distributed on the two input shafts, so that For example, the first input shaft gear wheels of the odd gears carries while the second input gear wheels has the even gears. When operating in one any gear are so, unless it is the smallest or largest gear, the next higher and next lower gear on the other drive shaft arranged. Since this is not active when using the other gear the torque transmission to the output shaft is involved, is it possible to get the desired of these two initially load-free to adjacent corridors then the friction clutch currently in the power flow located to open the input shaft and at the same time the to close the assigned to be activated gear friction clutch, without that there is a circuit-related interruption of traction comes. Dual clutch transmissions are therefore preferred in motor vehicles used, in which the advantages described to bear particularly come.

to Implementation of a parking brake in dual-clutch transmissions was proposed approaches known from conventional automatic transmissions adapt, which on a separate, form-fitting acting Locking element based, often the form of a on the transmission output shaft arranged rotationally fixed, provided with recesses or teeth Rades, which are switchable with one or more pawls or a fixed counter teeth are brought into operative connection can. This requires a significant extra Production costs and also means an increase in the Weight and construction volume of the dual-clutch transmission.

From the DE 199 50 696 A1 already a parking brake for a dual-clutch transmission is known, which uses the special structural properties of the dual-clutch transmission to achieve an effective parking brake. The dual-clutch transmission described has a first transmission input shaft connected to a first clutch with at least one starting gear G1, R, a second transmission input shaft connected to a second clutch with at least one driving gear G2, G4, G6 and a common transmission output shaft. At least one of the transmission input shafts are assigned to a plurality of gears, of which two gears are simultaneously switchable in a parking lock function. When the parking lock is engaged, the transmission output shaft is positively locked via the gear wheels of the two engaged gears and the relevant transmission input shaft and thus the relevant motor vehicle is secured against rolling away. A separate parking lock, for example in the form of a arranged on the transmission output shaft jaw clutch lock can thus be saved.

In a preferred embodiment of the dual-clutch transmission according to the DE 199 50 696 A1 The first transmission input shaft has all starting gears R, G1, and the two gears G2, G4 which can be simultaneously engaged in the parking brake function are assigned to the second transmission input shaft. Accordingly, the activation of the parking lock by the simultaneous insertion of two gears G2, G4, which are assigned to a common, no starting gear G1, R having transmission input shaft. In order to deactivate the parking brake, it is provided that first the tensioning strength of the simultaneously engaged gears is determined. In the presence of a small tension, the circuit of the two gears without further action immediately largely powerless, so be solved with comparatively low restoring forces of the respective gear knob. In the presence of a larger tension in the transmission, the direction of tension is additionally determined, a tensioning direction opposing starting gear is engaged and then closed the associated clutch until the tension is so low that the circuit of the two gears can be solved largely powerless.

However, there are also known dual-clutch transmission, in which the starting gears G1, R are realized distributed to the two input shafts, and thus require other control processes for activating and releasing a parking lock formed by the simultaneous insertion of two gears. Just If different starting processes are possible in connection with the release of such a parking lock, depending on the design of the dual-clutch transmission and the respective parking situation different control processes are possible, to those in the DE 199 50 696 A1 However, no information is provided.

Of the The invention is therefore based on the object, a method of control an automated dual clutch transmission to propose, according to the the function of a parking lock by the simultaneous switching of two gears associated with a common input shaft Can also be implemented in dual-clutch transmissions, where the starting gears are assigned to different input waves. Furthermore, should a dual clutch transmission with the structural requirements for Application of the method can be specified.

The Solution of the task concerning the method consists in Connection with the features of the preamble of claim 1 therein, that for activating the parking brake a starting gear G1; R and one the gears G3, G5; G2, G4, G6 of the same sub-transmission be inserted simultaneously. Advantageous embodiments and Further developments of the method according to the invention are the subject of assigned claims 2 to 22. A suitable for this process dual-clutch transmission is defined in independent claim 23, to which the favorable embodiments descriptive claims 24 to 27 relate.

As a result, the invention goes from an automated dual-clutch transmission from, which is a first partial transmission with a starting gear G1 for a forward approach and a first group of driving gears G3, G5 and on the input side with a first friction clutch K1 connected first input shaft, a second partial transmission with one a starting gear R for a reverse approach and a second group of travel G2, G4, G6 and the input side connected to a second friction clutch K2 second input shaft, and includes a common output shaft, wherein in a parking lock function two one of the two partial transmission assigned gears are inserted simultaneously. To activate the parking brake is provided according to the invention, a starting gear G1 or R and one of the driving gears G3, G5 or G2, G4, G6 of the same sub-transmission are inserted simultaneously. When the parking lock is engaged, the output shaft is thus over the gear wheels of the two inlaid gears as well the respective input shaft positively locked and so that the relevant motor vehicle against unintentional rolling away secured.

In contrast to the parking brake function according to the DE 199 50 696 A1 However, in the present case one of the starting gears G1 or R is already advantageously engaged in the parking lock function. On the one hand, the gear wheels of the lower gears, in particular the starting gears G1 and R, designed for the transmission of higher torques, correspondingly robust dimensioned and thus better suited for the forces occurring in the parking brake function than the gear wheels of the higher gears. On the other hand, in the parking lock function engaged starting gear G1 or R in the corresponding parking position, ie at a coincidence of the direction of travel of the engaged starting gear G1, R with the uphill and / or at a coincidence of the direction of travel of the engaged starting gear G1, R with the by the inserted gear D, R predetermined approach direction, are used directly either to release the parking brake and / or to start. Opposite the parking lock function after the DE 199 50 696 A1 Therefore, in most cases, simplified and accelerated control processes for releasing the parking brake and for starting from the engaged parking lock out.

There It can be assumed that in most cases forward is approached, it is preferably provided that for activation the parking lock the first forward G1 and the next higher Forward gear G3 of the first partial transmission are inserted. As a result, on the one hand, the robust construction of the gear wheels of the first gear G1 and the third gear G3 exploited. On the other hand can the first gear G1 in an uphill parking position of Motor vehicle directly to release the parking brake and regardless of the current roadway inclination immediately as Anfahrgang be used for a forward approach, which will be explained in more detail below.

alternative However, it is also possible that to activate the Parking lock the reverse gear R and the lowest Forward gear G2 of the second partial transmission are inserted. Also in this case, the sturdy construction of the gear wheels of the Reverse R and the second gear G2 exploited. In addition, the reverse gear R at a downhill directed parking position of the motor vehicle immediately to release the parking brake and regardless of the current roadway inclination immediately as a starting gear for a reverse drive be used.

For the aforementioned reasons, it is particularly advantageous if both gear combinations for realizing a parking brake function are available and can be used in each case depending on the current parking situation. For this purpose, the height and the direction of the road inclination is determined before the activation of the parking brake, and to activate the parking brake are in the presence of a forward in the direction of travel increasing or egg ner largely flat road surface of the first forward gear G1 and the next higher forward gear G3 of the first sub-gear engaged, whereas in the presence of a sloping in the forward direction roadway reverse gear R and the lowest forward gear G2 of the second sub-transmission 4 be inserted. This ensures that the to release the tension of the two engaged in the parking lock function gears G1, G3; R, G2 required, uphill starting gear G1; R is already inserted and to release the parking brake only the relevant friction clutch K1; K2 at least partially needs to be closed.

There at least releasing the parking brake under all operating conditions must be possible without outside help, a safety function is preferably provided with the insert prevents the parking lock on a too steep road section can be. For this purpose, it is specifically provided that before activation the parking brake the height of the current slope force determined and with one for the release of the parking lock available maximum driving force of the drive motor is compared, and that the parking lock function is present one of the maximum driving force below or reaching Downgrade force is released, whereas the parking lock function in the presence of a maximum driving force bordering Downgrade force is locked. In the case of the locked, so not available parking lock function is the driver forced to park the vehicle either with the parking brake or temporarily with the service brake and keep If necessary, another parking space with a lower roadway inclination to approach, in which the parking lock function is released again and thus available.

to Determining the downgrade force are preferred the amount and the direction of the current roadway inclination and the current vehicle mass determined and calculates the current downhill power. The investigation the vehicle mass can in a conventional manner in the form of a carried out during the previous driving test driving resistance balance be performed.

at an equipment of the motor vehicle with a hitch is useful for determining the slope force additionally recorded, whether currently a trailer the vehicle is attached. This can be z. B. by the evaluation of the assignment of the socket of the hitch respectively. When determined trailer operation, the additional Vehicle mass of the trailer, if not already over a driving resistance balance is done by a corresponding Surcharge on the vehicle mass of the tractor considered become.

In order to the driver of the situation of temporarily not to Available parking lock not surprised If the parking lock function is blocked, an audible and / or optical warning signal. The driver will thus by the z. B. trained as a warning tone and / or hazard warning lights Warning signal about the currently unavailable Standing parking lock function informed and can timely react, z. B. by the operation of the service brake or by approaching a less steep Abstelifläche.

to Assistance of the driver in this critical situation can also be provided that an automatically operable Service brake at least briefly automatically actuated which is possibly surprising for the driver occurring rolling back of the motor vehicle can be prevented can.

to Control of a start-up procedure from the closed parking lock out can be provided that before releasing the parking brake the direction of travel of the starting gear engaged in the parking lock function G1, R and the direction of travel of the engaged gear D, R detected be that tentatively inserted in the parking lock function Gears G3, G2 within a predetermined time with less Stellkraft is designed, and that the control processes for driving-related release of the parking lock depending on a successful or unsuccessful laying out of the travel G3, G2 and the detected directions are controlled.

If the layout of the travel G3, G2 within the predetermined period of time has taken place and the direction of travel of the engaged in the parking lock function Starting gear G1, R with the direction of travel of the engaged gear D, R matches, can start moving directly through the closing of the associated partial transmission associated Friction clutch K1, K2 done. This means, for example, that with gears G1, G3 engaged in the parking lock function after laying out the third gear G3 with the forward gear engaged D by closing the first friction clutch K1 in the first Gear G1 is approached.

If the laying out of the travel G3, G2 has taken place within the predetermined period of time, but the direction of travel of the starting gear G1, R engaged in the parking lock function is opposite to the direction of travel of the engaged gear R, D, then more control steps are required. In this case, initially engaged in the parking lock function starting gear G1, R designed largely load-free, then the direction of travel of the engaged gear R, D corresponding starting gear R, G1 of the other subtransmission largely loaded unloaded, and then approached by closing the respective sub-transmission associated friction clutch K2, K1.

This means, for example, that when engaged in the parking lock function Gears G1, G3 after laying out the third gear G3 initially also the first gear G1 is designed, then the second partial transmission assigned reverse gear R is engaged, and with engaged reverse gear R by closing the second friction clutch K2 in reverse R is approached.

alternative for the experimental laying out of the engaged in the parking lock function Movement G3, G2 can also be provided that before the Release the parking lock the height and the direction the current downgrade force determined and the direction of travel of the starting gear G1, R engaged in the parking lock function the direction of travel of the engaged gear D, R are detected, and that the control processes for approach-related release the parking brake depending on these operating parameters to be controlled.

at Presence of a given lower force limit below Downhill force and a coincidence of the direction of travel of the engaged in the parking lock function starting gear G1, R with the direction of travel of the engaged gear D, R is first the in the parking brake function inserted G3, G2 largely load-free, that is, with a comparatively low actuating force of the associated gear actuator, designed and then by closing the friction gear K1 associated with the relevant partial transmission, K2 approached.

This means, for example, that when inserted in the parking lock function Gears G1, G3 initially designed the third gear G3 and, subsequently, with the forward gear D engaged by closing the first friction clutch K1 in the first Gear G1 is approached.

at Presence of a given lower force limit below Downhill force and one to the direction of travel in the parking lock function engaged approach G1, R opposite direction of travel the engaged gear R, D but more control steps are required. In this case, initially both are in the parking lock function inlaid gears G1, G3 or R, G2 largely load-free designed. Then the direction of travel of the engaged gear is R, D corresponding starting gear R, G1 of the other subtransmission largely unloaded and then by closing the respective sub-transmission associated friction clutch K2, K1 started.

This means, for example, that when engaged in the parking lock function G1, G3 initially at about the same time first gear G1 and third gear G3 are designed, then the the second sub-transmission associated reverse gear R is engaged and with the reverse gear engaged R by closing the second friction clutch K2 in reverse R is approached.

If the tentative interpretation of the inserted in the parking lock function Movement G3, G2 failed within the specified time period is, or a down force exceeding or exceeding the predetermined lower force limit was determined, arise for starting from the closed parking brake each similar control processes, depending on the direction of the road inclination, the direction of travel of the starting gear engaged in the parking lock function G1 or R, and the predetermined by the inserted gear D, R approach direction differ from each other.

So is in case not done laying out the drive G3, G2 or if present one of the predetermined lower force limit reaching or exceeding Downhill force and a coincidence of the direction of travel of the engaged in the parking lock function starting gear G1, R with the direction of travel of the engaged gear D, R at an uphill directed direction of travel provided that the part of the transmission the gears G1, G3 engaged in the parking lock function, R, G2 associated friction clutch K1, K2 is closed so far, until the tension of the two gears G1, G3; R, G2 largely is lifted, that then the inserted in the parking lock function Gauge G3, G2 is designed largely fast-free, and that below by further closing the relevant friction clutch K1, K2 is approached.

This means, for example, that when the vehicle is parked uphill, engaged forward gear D and in the parking lock function inlaid gears G1, G3 first the relevant first partial transmission associated first friction clutch K1 partially is concluded that then the third gear G3 is designed, and that by further closing the first friction clutch K1 in first gear G1 is started uphill.

If the travel G3, G2 has not been laid out, or if a downhill force which reaches or exceeds the predefined lower force limit is present and the direction of travel of the starting gear G1, R engaged in the parking brake function coincides with the Direction of travel of the engaged gear D, R in a downhill direction of travel, however, provided that initially the uphill directional starting R, G1 of the other subtransmission is loaded unloaded, then that the other sub-transmission associated friction clutch K2, K1 is closed so far that the tension the two engaged in the parking lock function gears G1, G3; R, G2 is largely canceled, that then the engaged in the parking brake function gear G3, G2 is designed largely load-free, then by closing the engaged in the parking lock function gear G1, R friction clutch K1, K2 and simultaneous opening of the uphill starting gear R, G1 associated friction clutch K2, K1 is approached, and finally the uphill directed starting gear R, G1 is designed without load.

This means, by way of example, that when parked in a downhill vehicle, engaged forward gear D and in the parking lock function inlaid G1 or G3 first the the second sub-transmission associated, uphill reverse gear R is inserted, then the associated second friction clutch K2 is partially closed, then the third gear G3 largely is designed load-free, subsequently by simultaneous closing the first friction clutch K1 associated with the first gear G1 and opening the second friction clutch K2 in the first gear G1 forward is approached downhill, and finally the reverse gear R is designed.

at not interpreted layout of the G3, G2 or if present one of the predetermined lower force limit reaching or exceeding Downgrade force and one of the direction of travel in the parking lock function inlaid approach G1, R opposite and uphill Direction of travel of the engaged gear R, D is provided, that initially the uphill starting gear R, G1 of the other sub-transmission is loaded load-free, that then the the other sub-transmission associated friction clutch K2, K1 so far concluded that the tension of the two in the parking lock function inlaid gears G1, G3; R, G2 is largely repealed, that then the two engaged in the parking lock function Gears G1, G3; R, G2 be designed largely load-free, and that by further closing the respective friction clutch K2, K1 is approached.

This means, for example, that when the vehicle is parked downhill, engaged reverse gear R and in the parking lock function inlaid gears G1, G3 first of the second Partial transmission associated, uphill reverse gear R is inserted, then the associated second friction clutch K2 is partially closed, then the first gear G1 and the third Gang G3 be designed largely fast-free, and subsequently by further closing the second friction clutch K2 backwards is started uphill.

at not interpreted layout of the G3, G2 or if present one of the predetermined lower force limit reaching or exceeding Downgrade force and one of the direction of travel in the parking lock function inlaid approach G1, R opposite and downhill directed Direction of travel of the engaged gear R, D is provided, however, that first the part of the transmission in the parking brake function inlaid gears G1, G3; R, G2 associated friction clutch K1, K2 is closed so far that the tension of the two Gears G1, G3; R, G2 is largely canceled, that then the engaged in the parking lock function gear G3, G2 largely designed without load and the downhill directed R, G1 of the other sub-transmission is loaded load-free, that subsequently by closing the other sub-transmission associated Friction clutch K2, K1 and simultaneous opening of the assigned in the parking lock function starting gear G1, R assigned Friction clutch K1, K2 will go on, and that concluding the starting gear G1, R engaged in the parking lock function is load-free is interpreted.

This means, for example, that when the vehicle is parked uphill, engaged reverse gear R and in the parking lock function inlaid gears G1, G3 first this two gears associated first friction clutch K1 partially closed, then the third gear G3 designed and the downhill directed reverse gear R of the second partial transmission is inserted, subsequently by simultaneous closing the reverse gear R associated second friction clutch K2 and opening the first gear G1 associated first Friction clutch K1 approached downhill and finally the first gear G1 is laid out.

Since the control of the starting process by a corresponding operation of the accelerator pedal for the driver may be too demanding, the engine torque is automatically raised by increasing the speed of the drive motor at the beginning of the release of the parking brake or the start. As a result, both stalling of the drive motor and rolling back of the motor vehicle against the predetermined by the inserted gear D or R approach direction can be avoided. The drive-related increase in engine speed is similar to that in a cold start and is therefore despite a certain comfort restriction to be accepted by the driver.

While the release of the parking lock and the startup becomes the activation a manual shift mode M of the dual-clutch transmission, in which Switching operations are manually triggered, locked, to ensure a safe process of releasing the parking brake and to ensure the starting process. The blocking of the manual Switching mode M can be achieved by a controllable locking mechanism, with a pivoting of the selector lever of a control panel can be prevented in the manual shift gate, or by a Software-based blocking function to be realized.

A in automated manual transmissions usual gear indicator is with the parking lock always the designated Show letter P In the present realization of a parking brake by the simultaneous insertion of two courses of one Partial transmission of a dual-clutch transmission, this is to achieve a clear indication appropriate also handled, and not about those in the parking lock function actually inserted courses, such. G1 and G3. Too too at the approach-related release of the parking brake a functionally compliant To ensure display, it is preferably provided that with activated parking lock a gear indicator as long as the symbol P for an engaged parking lock indicates, until at least one of the gears G1 engaged in the parking lock function, G3; R, G2 is designed, and an actuation of the accelerator pedal to a starting movement of the vehicle in by the inserted Drive D, R predetermined direction leads. After that will then be in accordance with the actual Approach direction of the corresponding starting gear G1 for a Forward starting gear or R for a reverse starting gear displayed.

outgoing from a dual-clutch transmission that uses a first partial transmission one a starting gear G1 for a forward approach and a first group of lanes G3, G5 and the input side connected to a first friction clutch K1 first input shaft, a second partial transmission with a starting gear R for a reverse approach and a second group of driving G2, G4, G6 and having Input side connected to a second friction clutch K2 second input shaft, and includes a common output shaft, and in which in a parking lock function two one of the two partial transmissions associated Gears are insertable at the same time, is to carry out the process of the invention provided that in at least one of the partial transmissions, but preferably in both partial transmissions in each case one starting gear G1, R and one driving gear G3, G2 independently switchable from each other and in a parking lock function at the same time can be inserted.

to Implementation of the above-described control processes for engaging and disengaging the parking brake and for starting from the engaged Parking lock out a parking brake control device is provided, on the one hand with at least one sensor for determining a current operating parameters and, on the other hand, with gear actuators for and laying out the gears G1, G2, G3, R and with clutch plates for closing and opening the friction clutches K1, K2 communicates.

at For example, one of the sensors may be a tilt sensor to determine the amount or the amount and the direction act on the current roadway inclination. Another sensor can a weight sensor for determining the current vehicle mass or a load sensor to determine the current load. From the corresponding sensor data, the for the control of the parking brake relevant operating parameters, such as the Amount and the direction of the current downgrade force of the motor vehicle, be determined.

Around the driver about the status of the parking brake and one off informing the engaged parking lock out starting is preferably arranged in the field of vision of the driver and of the Parking lock control device provided controllable gear indicator.

To illustrate the invention, the description is accompanied by a drawing in which the only 1 shows the schematic structure of a dual-clutch transmission, in which the inventive method is applicable.

A dual-clutch transmission 1 according to 1 , which is used below by way of example for explaining the method according to the invention, comprises a first partial transmission 2 with a first input shaft having a starting gear G1 for forward driving and a first group of driving gears G3, G5 and the input side connected to a first friction clutch K1 3 , a second partial transmission 4 with a second input shaft having a starting gear R for a reverse approach and a second group of driving gears G2, G4, G6 and the input side connected to a second friction clutch K2 5 , and a common output shaft 6 ,

The friction clutches K1, K2 are actively closable and in the present example designed as pressure-actuated multi-plate clutches. On the input side is designed as a combustion piston engine drive motor 7 over its crankshaft 8th and a drive shaft 9 with a distributor stage 10 of the dual-clutch transmission 1 in connection. The trained as spur gear distributor stage 10 consists of a rotationally fixed to the drive wave 9 connected drive wheel 11 , one with the drive wheel 11 in meshing engagement and non-rotatably connected to the input element of the first friction clutch K1 first output gear 12 , and one with the drive wheel 11 in meshing engagement and non-rotatably connected to the input element of the second friction clutch K2 second output gear 13 , The output element of the first friction clutch K1 is non-rotatable with the input shaft 3 of the first partial transmission 2 connected, and the output element of the second friction clutch is rotatably connected to the input shaft 5 coupled the second sub-transmission.

The gear stage of the first gear G1 is replaced by a on the first input shaft 3 rotatably mounted idler gear 14 and one with this in meshing engagement and rotationally fixed on the output shaft 6 fixed fixed wheel 15 educated. To the circuit of the first gear are rad between the lot 14 and the input shaft 3 arranged a gear clutch and a shift sleeve, which form an independently switchable first shift package S1. The gear stages of the third gear G3 and the fifth gear G5 are arranged axially adjacent to each other and are in a conventional manner in each case by a on the first input shaft 3 rotatably mounted idler gear 16 respectively. 18 and a rotationally fixed on the output shaft 6 fixed fixed wheel 17 respectively. 19 educated. The associated gear clutches and a common shift sleeve are combined in a second shift package S2, so that the third gear G3 and the fifth gear G5 are only selectively switchable, so alternatively to one another and interpretable.

The speed stages of the second speed G2 and the fourth speed G4 are also arranged adjacent to each other and are respectively through a on the second input shaft 5 rotatably mounted idler gear 20 respectively. 21 and a rotationally fixed on the output shaft 6 fixed fixed wheel 15 respectively. 17 formed, where present in space-saving manner, the fixed wheels 15 and 17 of the first gear G1 and the third gear G3 be used with. The second clutch G2 and the fourth gear G4 associated gear clutches and a common shift sleeve are summarized in a third shift package S3, so that the second gear G2 and the fourth gear G4 are only selectively switchable.

The sixth speed gear G6 is engaged by one on the second input shaft 5 rotatably mounted idler gear 22 and one with this in meshing engagement and rotationally fixed on the output shaft 6 fixed fixed wheel 19 formed, in a space-saving manner, the fixed wheel 19 of the fifth gear G5 is used with. The reverse gear ratio R is disposed axially adjacent to the sixth speed gear stage G6 and becomes one on the second input shaft 5 rotatably mounted idler gear 23 , an idler 24 and a rotationally fixed on the output shaft 6 fixed fixed wheel 25 educated. The sixth gear G6 and the reverse gear R associated gear clutches and a common shift sleeve are summarized in a fourth shift package S4, so that the sixth gear G6 and the reverse gear R are only selectively switchable.

The output shaft 6 stands over an output shaft 26 with a differential gear 27 a driven vehicle axle in connection, of the two axle shafts 28 lead to the not shown drive wheels.

A the dual-clutch transmission 1 associated transmission control device 29 has a parking brake control device 30 on, in the data or signals of a tilt sensor 31 and a weight sensor 32 are readable. The transmission control device 30 is about simplified communication means shown as a double arrow 33 with the not shown gear actuators of the switching packets S1, S2, S3, S4 in combination. The parking brake control device 30 also has a signaling connection to a switch 34 for manual release of the engagement and disengagement of the parking brake and with a gear indicator 35 to display the currently engaged gear G1 to G6, R or the effective gear P, R, N, D on.

The parking brake control device 30 determined with the aid of sensor data from the inclination sensor 31 and the weight sensor 32 the current road gradient and the current vehicle mass and calculates the current downgrade power of the relevant motor vehicle. Depending on this, it is decided whether the parking brake function is enabled or disabled. If the parking lock function is enabled, the driver can with the vehicle standstill and possibly actuated service brake via the switch 34 trigger the parking lock. At the same time, two independently variable gears, which are the same partial transmission, are used at the same time 2 or 4 are assigned, inserted by means of the respective gear clutches or the switching packets S1, S2 or S3, S4, whereby the output shaft 6 via the gears of the respective gears G1, G3 or R, G2 and the common input shaft 3 or 5 blocked and thus the relevant motor vehicle is secured against rolling away.

For the parking lock function of the dual-clutch transmission 1 Preferably, the first gear G1 and the third gear G3 are used, which are the first partial transmission 2 with the first input shaft 3 are assigned, and due to the arrangement the respective gear wheel sets and the associated gear clutches or switching packages S1, S2 are independently switchable and thus simultaneously einiegbar. However, for the parking lock function, the use of the second gear G2 and the reverse gear R is possible, the second part of the transmission 4 with the second input shaft 5 are assigned, and due to the arrangement of the respective gear wheel sets and the associated gear clutches or switching packages S3, S4 are also independently switchable and thus also simultaneously einiegbar.

The selection of each engaged in the parking lock function gears G1, G3 or R, G2 is advantageously carried out depending on the amount and the direction of the road inclination on which the vehicle is to be parked. Thus, it is expedient if the first gear G1 and the third gear G3 of the first subtransmission are present in the presence of a road surface that is increasing in the forward direction of travel or a substantially flat roadway 2 and in the presence of a sloping in the forward direction roadway, the reverse gear R and the second gear G2 of the second sub-transmission 4 be inserted in the parking lock function.

The Control processes for releasing the parking lock done depending on the amount and the direction of the current one Downhill force, the direction of travel in parking brake function engaged starting gear G1 or R and from the direction of the engaged gear D or R.

For example, in the case of a motor vehicle parked uphill with the gears G1 and G3 engaged in the event of a downhill driving force reaching or exceeding a predetermined lower force limit, it is provided that initially the first partial transmission 2 assigned first friction clutch K1 is closed so far that the tension of the two gears G1, G3 is largely canceled, that then the engaged in the parking lock function third gear G3 is designed largely load-free, and that is approached by further closing the first friction clutch K1 uphill forward ,

If, however, the motor vehicle is parked downhill with the engaged gears R, G2, it is provided that the first partial transmission is initially present when the downhill driving force reaches or exceeds the predefined lower force limit value and the forward gear D is engaged 4 assigned second friction clutch K2 is closed so far that the tension of the two gears R, G2 is largely canceled, that then designed in the parking lock function second gear G2 designed largely load-free and the downhill effective first gear G1 of the first sub-transmission 2 load-free is inserted, that is then approached by the simultaneous closing of the first friction clutch K1 and opening the second friction clutch K2 forward downhill, and that finally the engaged in the parking lock reverse gear R is designed load-free.

When starting up from the engaged parking lock, the gear indicator will show 35 as long as the signal P for the engaged parking brake on until at least one of the engaged in the parking lock function gears G1, G3 and R, G2 is designed, and an actuation of the accelerator pedal to a starting movement of the vehicle in the predetermined by the selected gear D approach direction , So in the examples mentioned in the forward direction, leads.

1

Double clutch

2

first subtransmissions

3

First input shaft

4

second subtransmissions

5

Second input shaft

6

output shaft

7

drive motor

8th

crankshaft

9

drive shaft

10

distribution stage

11

drive wheel

12

first output gear

13

second output gear

14

Losrad from G1

15

fixed gear from G1, G2

16

Losrad from G3

17

fixed gear from G3, G4

18

Losrad from G5

19

fixed gear from G5, G6

20

Losrad from G2

21

Losrad from G4

22

Losrad from G6

23

Losrad from R

24

idler from R

25

fixed gear from R

26

output shaft

27

differential gear

28

axle shaft

29

Transmission control device

30

Parking brake control device

31

tilt sensor

32

weight sensor

33

means of communication

34

switch

35

gear indicator

D

Forward gear

G1

first Forward gear

G2

second Forward gear

G3

third Forward gear

G4

fourth Forward gear

G5

fifth Forward gear

G6

six Forward gear

K1

First friction clutch

K2

Second friction clutch

M

manual switching mode

N

Idle position

P

Park-gear

R

Reverse gear, Reverse gear

S1

first switching package

S2

second switching package

S3

third switching package

S4

fourth switching package

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19950696 A1 [0005, 0006, 0007, 0011, 0011]

Claims (27)

Method for controlling an automated dual-clutch transmission ( 1 ), which is a first partial transmission ( 2 ) with a first input shaft (G1) for a forward approach and a first group of driving gears (G3, G5) and on the input side with a first friction clutch (K1) connected to the first input shaft ( 3 ), a second partial transmission ( 4 ) having a second input shaft (R) for a reverse drive and a second group of drive gears (G2, G4, G6) and the input side connected to a second friction clutch (K2) second input shaft ( 5 ), and a common output shaft ( 6 ), wherein in a parking lock function two one of the two partial transmissions ( 2 . 4 ) associated gears are engaged simultaneously, characterized in that for activating the parking brake a starting gear (G1; R) and one of the driving gears (G3, G5, G2, G4, G6) of the same sub-transmission ( 2 ; 4 ) are inserted simultaneously. A method according to claim 1, characterized in that for activating the parking brake the first forward gear (G1) and the next higher forward gear (G3) of the first sub-transmission ( 2 ) be inserted. Method according to Claim 1 or 2, characterized in that, for activating the parking brake, the reverse gear (R) and the lowest forward gear (G2) of the second subtransmission ( 4 ) be inserted. Method according to at least one of claims 1 to 3, characterized in that before the activation of the parking brake, the height and the direction of the road inclination are determined, and that for activating the parking brake in the presence of a forward driving direction or a substantially flat roadway, the first forward gear ( G1) and the next higher forward gear (G3) of the first partial transmission ( 2 ) and in the presence of a sloping in the forward direction roadway, the reverse gear (R) and the lowest forward gear (G2) of the second sub-transmission ( 4 ) be inserted. Method according to at least one of claims 1 to 4, characterized in that determined before the activation of the parking brake, the amount of the current downgrade force and with an available for releasing the parking brake maximum driving force of the drive motor ( 7 ), and that the parking lock function is released in the presence of a downhill force exceeding or attaining the maximum drive force, whereas the parking lock function is disabled in the presence of a downhill force exceeding the maximum drive force. Method according to claim 5, characterized in that that for determining the slope force the current road inclination in terms of amount and direction as well as the current vehicle mass be determined, and calculated from the current slope force becomes. Method according to Claim 6, characterized that in an equipment of the motor vehicle with a Towing device for determining the slope force In addition, it is recorded whether currently a trailer attached to the motor vehicle. Method according to at least one of the claims 5 to 7, characterized in that at a blocking of the parking lock function an audible and / or visual warning signal is output. Method according to at least one of the claims 5 to 8, characterized in that at a blocking of the parking lock function an automatically operable service brake at least for a short time is automatically operated. Method according to at least one of the claims 1 to 9, characterized in that before loosening the Parking lock the direction of travel of the engaged in the parking lock function Starting gear (G1; R) and the direction of travel of the engaged gear (D; R) be captured that tentatively in the parking lock function engaged travel (G3, G2) within a predetermined period of time is swept out with little force, and that the control processes for driving-related release of the parking lock depending on a successful or unsuccessful laying out of the driving gear (G3; G2) and the detected directions of travel are controlled. Method according to Claim 10, characterized in that, when the travel (G3; G2) has been laid out and the driving direction of the starting gear (G1; R) engaged in the parking brake function coincides with the direction of travel of the engaged driving gear (D; the relevant sub-transmission ( 2 ; 4 ) is moved to the associated friction clutch (K1, K2). Method according to Claim 10, characterized in that, when the travel path (G3; G2) has been laid out and the direction of travel of the starting gear (G1; R) engaged in the parking lock function is opposite, the driving direction (R; D) engaged in the parking lock function is engaged Starting gear (G1; R) is designed largely load-free, then the direction of travel of the engaged gear (R; D) corresponding starting gear (R; G1) of the other subtransmission is largely load-free, and then by closing the respective sub-transmission ( 4 ; 2 ) associated friction clutch (K2, K1) is approached. Method according to at least one of the claims 1 to 9, characterized in that before loosening the Parking lock the height and the direction of the current slope force determined and the direction of travel of the engaged in the parking lock function Starting gear (G1, R) and the direction of travel of the engaged gear (D, R) are detected, and that the control processes for Driving-related release of the parking lock depending on these operating parameters are controlled. A method according to claim 13, characterized in that in the presence of a predetermined lower force limit below falling downhill force and a coincidence of the direction of the engaged in the parking lock function starting gear (G1; R) with the direction of travel of the engaged gear (D; R) of the engaged in the parking brake function Fahrgang (G3, G2) is designed largely load-free, and then by closing the respective sub-transmission ( 2 ; 4 ) is moved to the associated friction clutch (K1, K2). A method according to claim 13, characterized in that in the presence of a predetermined lower force limit below falling downhill force and to the direction of travel of the engaged in the parking lock function starting gear (G1; R) opposite direction of travel of the engaged gear (R; D) both engaged in the parking lock function gears (G1, G3, R, G2) are designed largely free of load, then the direction of travel of the engaged gear (R; D) corresponding starting gear (R; G1) of the other subtransmission is largely load-free, and then by closing the respective sub-transmission ( 4 ; 2 ) is approached associated friction clutch (K2, K1). A method according to claim 10 or 13, characterized in that when not laid out the driving gear (G3; G2) or in the presence of the predetermined lower force limit reaching or exceeding Hangabtriebskraft and a coincidence of the direction of travel in the parking lock function engaged starting gear (G1; R) with the direction of travel of the engaged gear (D; R) in an uphill direction of the direction of the partial transmission ( 2 ; 4 ) of the engaged in the parking lock function gears (G1, G3, R, G2) friction clutch (K1, K2) is closed so far that the tension of the two gears (G1, G3, R, G2) is largely canceled, that then the in the gear lock function engaged gear (G3, G2) is designed largely load-free, and then by further closing the respective friction clutch (K1, K2) is approached. A method according to claim 10 or 13, characterized in that when not laid out the driving gear (G3; G2) or in the presence of the predetermined lower force limit reaching or exceeding Hangabtriebskraft and a coincidence of the direction of travel in the parking lock function engaged starting gear (G1; R) with the direction of travel of the engaged gear (D; R) in a downhill direction of the uphill directional starting gear (R; G1) of the other sub-transmission ( 4 ; 2 ) is loaded load-free, then the other sub-transmission ( 4 ; 2 K1) is closed so far that the tension of the two engaged in the parking lock function gears (G1, G3, R, G2) is largely canceled, then the set in the parking lock function drive (G3, G2) designed largely free of load is subsequently approached by closing the friction clutch (K1; K2) associated with the starting gear (G1; R) engaged in the parking lock function and simultaneously opening the friction clutch (K2; K1) associated with the uphill starting gear (R; G1); uphill starting gear (R; G1) is designed without load. A method according to claim 10 or 13, characterized in that when not laid out the driving gear (G3; G2) or in the presence of the predetermined lower force limit reaching or exceeding downhill force and one of the direction of the engaged in the parking lock function starting gear (G1; R) opposite and uphill direction of travel of the engaged gear (R; D), the uphill directed gear (R; G1) of the other gear ( 4 ; 2 ) is loaded load-free, then the other sub-transmission ( 4 ; 2 ) so far closed that the tension of the two engaged in the parking lock function gears (G1, G3, R, G2) is largely canceled, then the two engaged in the parking lock function gears (G1, G3, R, G2) are designed largely load-free, and by further closing the respective friction clutch (K2, K1) is approached. A method according to claim 10 or 13, characterized in that when not laid out the driving gear (G3; G2) or in the presence of the predetermined lower force limit reaching or exceeding downhill force and one of the direction of the engaged in the parking lock function starting gear (G1; R) opposite and downhill direction of travel of the engaged gear (R; D) which the sub-transmission ( 2 ; 4 ) of the gears engaged in the parking lock function (G1, G3; R, G2) associated friction clutch (K1; K2) is closed so far that the tension of the two gears (G1, G3, R, G2) is largely canceled, the engaged in the parking lock function drive (G3, G2) designed largely load-free, the downhill directed starting gear (R; G1) of the other sub-transmission ( 4 ; 2 ) is loaded without load, by closing the other partial transmission ( 4 ; 2 ) and simultaneous opening of the friction clutch (K1; K2) associated with the starting gear (G1; R) engaged in the parking lock function, and finally the starting gear (G1; R) engaged in the parking lock function is designed to be load-free. Method according to at least one of the claims 10 to 19, characterized in that at the beginning of Lösens the parking brake or starting the engine torque by increasing the speed of the drive motor is raised automatically. Method according to at least one of claims 10 to 20, characterized in that during the release of the parking brake and the starting the activation of a manual shift mode (M) of the dual-clutch transmission ( 1 ) is locked. Method according to at least one of Claims 1 to 21, characterized in that, when the parking lock is activated, a gear indicator ( 35 ) as long as a signal (display P) indicates an engaged parking brake until at least one of the engaged in the parking lock function gears (G1, G3, R, G2) is designed, and an actuation of the accelerator pedal to a starting movement of the vehicle in by the engaged gear (D; R) leads predetermined direction. Dual-clutch transmission for carrying out the method according to at least one of claims 1 to 16, comprising a first partial transmission ( 2 ) having a first input shaft (G1) for forward driving and a first group of driving gears (G3, G5) and connected on the input side to a first friction clutch (K1) ( 3 ), a second partial transmission ( 4 ) with a second input shaft (R) for a reverse drive and a second group of drive gears (G2, G4, G6) and on the input side with a second friction clutch (K2) connected second input shaft ( 5 ), and a common output shaft ( 6 ) and in which in a parking lock function two of one of the two partial transmissions ( 2 . 4 ) associated gears are simultaneously inserted, characterized in that in at least one of the partial transmission ( 2 . 4 ) a starting gear (G1, R) and a driving gear (G3, G2) are independently switchable and simultaneously inserted in a parking lock function. Double-clutch transmission according to claim 23, characterized in that for controlling the engagement and disengagement of the parking brake and for starting from the inserted parking lock out a parking brake control device ( 30 ) provided, on the one hand, with at least one sensor ( 31 . 32 ) for determining a current operating parameter and on the other hand with gear actuators for engaging and disengaging the gears (G1, G2, G3, R) and with clutch actuators for closing and opening the friction clutches (K1, K2) is in communication. Double clutch transmission according to claim 24, characterized in that a tilt sensor ( 31 ) is provided for determining the amount and direction of the current roadway inclination. Double-clutch transmission according to claim 24 or 25, characterized in that a weight sensor ( 32 ) is provided for determining the current vehicle mass and / or a load sensor for determining the current payload. Dual-clutch transmission according to at least one of claims 23 to 26, characterized in that a gear indicator ( 35 ), which is arranged in the field of view of the driver and by the parking brake control device ( 30 ) is controllable.