DE102019205753A1 - Method for operating a hybrid drive train and hybrid drive train - Google Patents

Abstract

A method for operating a hybrid drive train (10), the hybrid drive train (10) having an input shaft (24) which is connected to an internal combustion engine via a separating clutch (K0), and having an output shaft arrangement (25), the input shaft (24) and the output shaft arrangement (25) is assigned a first partial transmission (44) in order to be able to set up an internal combustion engine driving mode, the hybrid drive train (10) having a first electrical machine (50) which is driven via a second partial transmission (46 ) is connected to the output shaft arrangement (25) in order to be able to set up a purely electric driving mode, the second partial transmission (46) having a planetary gear set (52) which can be shifted via at least one switching element (A), and the first partial transmission ( 44) and the second partial transmission (46) can be connected to one another via a coupling shift element (C) in such a way that a power split operation (EDA) can be set up, in which the drive power of the internal combustion engine (12) and the drive power of the first electric machine (50) are superimposed in the planetary gear set (52) and the superimposed drive power is directed to the output shaft arrangement (25), and the hybrid drive train (10) has a second electrical Machine (70) which is connected to the first sub-transmission (44), the method proceeding from a purely electric driving mode using the first electric machine (50) and with the coupling shift element (C) and shift element (A) open, the following Steps: starting the internal combustion engine (12) via the second electrical machine (70) if the internal combustion engine (12) is not already running, opening the separating clutch (K0), if it is closed, closing the coupling switching element (C) and driving the second electrical machine (70), such that the switching element (A) is relieved. Opening of the switching element (A), Synchr onizing the separating clutch (K0) by means of the first and / or the second electrical machine (50, 70), closing the separating clutch (K0) so that the power split mode (EDA) is set up.

Description

The present invention relates to a method for operating a hybrid drive train and relates to a hybrid drive train as such, the hybrid drive train having an input shaft which is connected to an internal combustion engine via a separating clutch, the hybrid drive train also having an output shaft arrangement, The input shaft and the output shaft arrangement are assigned a first sub-transmission in order to be able to set up an internal combustion engine driving mode, the hybrid drive train also having a first electric machine which is connected to the output shaft arrangement via a second sub-transmission in order to set up a purely electric driving operation can, wherein the second sub-transmission has a planetary gear set that can be shifted via at least one shift element, and wherein the first sub-transmission and the second sub-transmission can be connected to one another via a coupling shift element, such that a power ngsverzweigungsbetrieb can be set up, in which the drive power of the internal combustion engine and drive power of the first electrical machine are superimposed in the planetary gear set and the superimposed drive power is directed to the output shaft arrangement.

A hybrid drive train of the type mentioned above is from the document DE 10 2013 215 114 A1 known. With the hybrid drive train known from this document, two purely electric gear steps can be set up, which are shifted with positive-locking shift elements. In one embodiment, a start-up process can take place in the power-split operation, specifically even when an electrical energy store for storing the electrical machine is empty. The electric machine works as a generator during such a start-up process. In normal operation, the shorter of the two electric gear steps is purely electric. A transition from a purely electric driving mode to a power split mode is only possible with an interruption of the tractive effort.

Against this background, it is an object of the invention to provide an improved method for operating a hybrid drive train and an improved hybrid drive train.

The above object is achieved by a method for operating a hybrid drive train, the hybrid drive train having an input shaft that is connected to an internal combustion engine via a separating clutch, and an output shaft arrangement, the input shaft and the output shaft arrangement being assigned a first partial transmission , in order to be able to set up an internal combustion engine driving mode, wherein the hybrid drive train has a first electric machine which is connected to the output shaft arrangement via a second sub-transmission in order to be able to set up a purely electric driving operation, the second sub-transmission having a planetary gear set that is connected via at least one shifting element can be shifted, and wherein the first partial transmission and the second partial transmission can be connected to one another via a coupling shifting element in such a way that a power split mode can be set up with the drive power of the internal combustion engine and A Drive power of the first electric machine are superimposed in the planetary gear set and the superimposed drive power is passed to the output shaft arrangement, the hybrid drive train having a second electric machine that is connected to the first sub-transmission, and the method based on a purely electric driving mode Use of the first electrical machine and, with the coupling switching element open and the switching element closed, comprising the following steps: starting the internal combustion engine via the second electrical machine if the internal combustion engine is not already running; Opening the clutch, if it is closed; Closing the coupling switching element and driving the second electrical machine in such a way that the switching element is relieved; Opening the switching element; Synchronizing the separating clutch by means of the first and / or the second electrical machine; Closing the separating clutch so that the power split operation is established.

During the synchronization phase, the first and the second electrical machine are preferably regulated in such a way that the separating clutch becomes synchronous.

Before the coupling switching element is closed, it is preferred in the method according to the invention if it is synchronized beforehand. The synchronization is preferably carried out by regulating the speed of the second electrical machine, in particular by braking to zero.

According to a further preferred embodiment, the switching element is designed such that, in the closed state, it connects a member of the planetary gear set to a housing.

When the switching element is opened in the method according to the invention for setting up the power split operation, the two electrical machines superimpose their powers in the planetary gear set so that the tensile force is maintained.

Furthermore, the above object is achieved by a method for operating a hybrid Drive train, the hybrid drive train having an input shaft which is connected to an internal combustion engine via a separating clutch, and having an output shaft arrangement, the input shaft and the output shaft arrangement being assigned a first partial transmission in order to be able to set up internal combustion engine driving, the hybrid The drive train has a first electrical machine which is connected to the output shaft arrangement via a second sub-transmission in order to be able to set up a purely electric driving mode, the second sub-transmission having a planetary gear set that can be shifted via at least one shift element, and the first sub-transmission and the second subtransmissions can be connected to one another via a coupling shift element, in such a way that a power split mode can be set up in which the drive power of the internal combustion engine and drive power of the first electrical machine in the planetary gear set are superimposed gert and the superimposed drive power is routed to the output shaft arrangement, and wherein the hybrid drive train has a second electrical machine that is connected to the first sub-transmission, the method starting from the power split mode using the first electrical machine and the internal combustion engine and at with the disengaging clutch closed and the coupling switching element closed and the switching element disengaged, comprising the following steps: reducing the torque provided by the internal combustion engine; Opening the disconnect clutch; Synchronizing the switching element by means of the first electrical machine and / or the second electrical machine; and closing the switching element.

Furthermore, the above object is achieved by a hybrid drive train, with an input shaft which is connected to an internal combustion engine via a separating clutch, with an output shaft arrangement, the input shaft and the output shaft arrangement being assigned a first partial transmission in order to be able to set up internal combustion engine driving, with a first electrical machine, which is connected to the output shaft arrangement via a second sub-transmission in order to be able to set up a purely electric driving mode, wherein the second sub-transmission has a planetary gear set that can be shifted via at least one switching element, and wherein the first sub-transmission and the second Subtransmissions can be connected to one another via a coupling shift element in such a way that a power split operation can be set up, in which the drive power of the internal combustion engine and drive power of the first electrical machine are superimposed in the planetary gear set and the overl Agared drive power is passed to the output shaft arrangement, with a second electrical machine, which is connected to the first partial transmission, and with a control device which is set up to carry out a method according to the invention.

By providing the second electric machine, which is connected to the first partial transmission, it is possible to carry out a transition from purely electric driving mode to power split mode and a transition from power split mode to another driving mode, in particular all-electric driving mode, that essentially no interruption in traction occurs. The second electrical machine can apply a supporting torque in each case. The duration for which it is necessary to apply such a supporting torque is relatively short and can, for example, be less than five seconds, in particular less than three seconds. During this time it is necessary that the drive energy is taken from an electrical energy store in order to provide the supporting torque.

The second electrical machine can be dimensioned smaller than the first electrical machine. In particular, the rated power of the second electrical machine can be less than half the rated power of the first electrical machine.

The task is completely solved.

According to a preferred embodiment of the method, in which purely electric driving mode is assumed and a power split mode is to be set up (first aspect), it is preferred if the torque provided by the second electric machine is reduced after closing the disconnect clutch, in particular to Zero is reduced and / or when the torque provided by the internal combustion engine is increased.

After closing the separating clutch, the torque provided by the second electric machine can even change into the negative range (generator operation). The speed of the internal combustion engine can be increased.

The torques and speeds can preferably be set in such a way that the desired drive torque is provided and any desired energy supply to an electrical system is ensured.

According to a further preferred embodiment of the first aspect, in the step of synchronizing the separating clutch, that provided by the first electrical machine Reduced torque and increased the torque provided by the second electrical machine.

The changes in the torques are preferably carried out in such a way that a total output remains approximately constant.

At very low speeds it can happen that the first electric machine turns backwards and works as a generator. The second electrical machine, however, generally always works as a motor during the synchronization process. This applies in particular with the prerequisite that the purely electric driving operation, from which the method is based, takes place under tension.

According to a further preferred embodiment of the first aspect, a member of the planetary gear set can be connected to a housing via the switching element, the second electrical machine being regulated to a speed of zero before the step of closing the coupling switching element.

As a result, the coupling switching element is synchronized before closing.

In the method in which a different driving mode is set up based on the power split mode (second aspect), it is preferred if the torque provided by the second electrical machine is reduced and that provided by the first electrical machine in the step of synchronizing the switching element Torque is increased.

The two electrical machines are preferably regulated in such a way that the switching element becomes synchronous. If the switching element is designed to connect a member of the planetary gear set to a housing, this member is preferably braked to a speed of zero.

During the speed adjustment phase, the power of the first electrical machine preferably increases, the power of the second electrical machine preferably decreasing so that the total power remains approximately constant.

According to a further preferred embodiment of the second aspect, the coupling switching element is opened after the switching element is closed.

This can preferably be done without load.

After the coupling switching element has been opened, the second electrical machine is again available for other functions in the second aspect. For example, the second electrical machine can synchronize the separating clutch, and the separating clutch can then be closed. In this way, a serial driving operation is possible, in which the first electric machine provides electromotive drive power, the internal combustion engine driving the second electric machine as a generator.

In the method according to the second aspect, in which a different driving mode is set up based on the power split mode, in particular a serial mode, it is preferred if a supporting torque is applied to the planetary gear set during the reduction of the torque provided by the internal combustion engine, i.e. during the load reduction is applied solely by means of the second electrical machine. So that the second electrical machine requires little power for this purpose, the speed of the internal combustion engine (and thus also that of the second electrical machine) can be reduced before this process.

Overall, it is advantageous if a first coupling element of the coupling shift element assigned to the first sub-transmission is a loose wheel of a gear set for a gear stage of the first sub-transmission, in particular for a lowest gear stage of the first sub-transmission, in particular for one gear stage 1 .

The coupling switching element has the first coupling element and a second coupling element, which are connected to one another in a rotationally fixed manner when the coupling switching element is closed and are decoupled from one another when the coupling switching element is open. The second coupling member is preferably a coupling shaft which is connected to a member of the planetary gear set (preferably the sun gear) and which can preferably be connected to a housing via the switching element.

It is particularly advantageous if the coupling shaft can connect the link of the planetary gear set connected to the coupling shaft to a further link of the planetary gear set via a further switching element, in order in this way to direct a torque provided by the first electric machine with a further ratio to the output shaft arrangement to be able to.

Furthermore, it is advantageous overall if the second electric machine is connected to a gear set for a gear stage of the first sub-transmission, in particular to a gear set for a third gear stage of the first sub-transmission or a third lowest gear stage of the first sub-transmission.

In a further embodiment, it is preferred if the separating clutch and / or the coupling switching element and / or the switching element is or are designed as form-fitting switching elements.

In particular, the separating clutch is not a starting clutch and, in particular, is not a power shift clutch. Even if the separating clutch is designed as a friction clutch, it is preferably not operated in a slip mode.

According to a further overall preferred embodiment, the hybrid drive train has a plurality of gear sets that connect the input shaft and the output shaft arrangement and form the first partial transmission. The gear sets can in particular be spur gear sets. The gear sets of the first partial transmission can each have an idler gear and a fixed gear.

The output shaft assembly may be a single output shaft, such as in the document DE 10 2013 215 114 A1 is revealed.

However, the output shaft arrangement can also have a first and a second output shaft which are connected to a power distribution device, such as a differential, via respective output gears.

If the output shaft arrangement has two output shafts, the gear sets can also have a fixed gear and two idle gears, in the manner of a “double use”. In this way, an axially particularly compact design can be implemented.

In an alternative embodiment, the first partial transmission of the hybrid drive train is formed by at least one further planetary gear set and further shifting elements. This enables a compact design to be achieved.

According to a further generally preferred embodiment, a first link of the planetary gear set is connected to the first electrical machine and / or a second link of the planetary gear set can be connected to the first partial transmission via the coupling shift element and / or a third link of the planetary gear set is connected to the output shaft arrangement.

The first link is preferably a ring gear of the planetary gear set. The second link is preferably a sun gear of the planetary gear set. The third link is preferably a planet carrier of the planetary gear set.

If the planetary gear set has a stationary gear ratio of, for example, i0 = 2, the following can be achieved. Assuming a block rotation of the planetary gear set, the power of both electrical machines is regulated in the phase of speed adjustment (synchronization). Through the above It is possible that the first electrical machine has to contribute two thirds of the drive power and the second electrical machine only one third of the required drive power. In the preferred embodiment, the torque on the sun gear is therefore only half as great as on the ring gear. Consequently, in the preferred embodiment, the second electrical machine can be designed both with less power and with less torque than the first electrical machine. The arrangement of the planetary gear set selected above (first electrical machine on the ring gear, second electrical machine via the coupling switching element on the sun gear and output on the planet carrier or web) is therefore particularly advantageous.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.

• 1 eine schematische Darstellung einer Ausführungsform eines erfindungsgemäßen Antriebsstranges;
• 2 eine Schalttabelle der Trennkupplung und von verschiedenen Schaltelementen des Hybrid-Antriebsstranges der 1 für einen verbrennungsmotorischen Fahrbetrieb in den Gangstufen 1 bis 4 sowie in einem Leistungsverzweigungsbetrieb (EDA);
• 3 eine Schalttabelle für zwei elektrische Gangstufen E1, E2, die mittels der ersten elektrischen Maschine des Antriebsstranges der 1 eingerichtet werden, sowie eine Schalttabelle für die Gangstufen 1 bis 4 und EWA, die mittels der zweiten elektrischen Maschine des Antriebsstranges der 1 eingerichtet werden können;
• 4 eine schematische Darstellung einer weiteren Ausführungsform eines erfindungsgemäßen Hybrid-Antriebsstranges;
• 5 eine Schalttabelle für den Antriebsstrang der 4;
• 6 eine schematische Darstellung einer weiteren Ausführungsform eines erfindungsgemäßen Hybrid-Antriebsstranges;
• 7 eine schematische Darstellung einer weiteren Ausführungsform eines erfindungsgemäßen Hybrid-Antriebsstranges;
• 8 eine Schalttabelle für die Antriebsstränge der 6 und 7;
• 9 eine schematische Darstellung einer weiteren Ausführungsform eines erfindungsgemäßen Hybrid-Antriebsstranges; und
• 10 eine Schalttabelle für den Antriebsstrang der 9.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

• 1 a schematic representation of an embodiment of a drive train according to the invention;
• 2 a switching table of the disconnect clutch and of various switching elements of the hybrid drive train of 1 for internal combustion engine driving in the gears 1 to 4th as well as in a service distribution company (EDA);
• 3 a shift table for two electrical gear steps E1 , E2 , which by means of the first electric machine of the drive train of the 1 as well as a shift table for the gear steps 1 to 4th and EWA, which by means of the second electric machine of the drive train of the 1 can be set up;
• 4th a schematic representation of a further embodiment of a hybrid drive train according to the invention;
• 5 a shift table for the drive train of the 4th ;
• 6 a schematic representation of a further embodiment of a hybrid drive train according to the invention;
• 7th a schematic representation of a further embodiment of a hybrid drive train according to the invention;
• 8th a shift table for the drive trains of the 6 and 7th ;
• 9 a schematic representation of a further embodiment of a hybrid drive train according to the invention; and
• 10 a shift table for the drive train of the 9 .

In 1 a hybrid drive train according to a first embodiment is shown schematically and generally denoted by 10.

The hybrid powertrain includes an internal combustion engine 12 , the crankshaft with an input member of a clutch assembly 14th is connected, which is a disconnect clutch K0 having. An output member of the clutch assembly 14th is with a gear arrangement 16 connected. An output of the gear assembly 16 is with a power distribution facility 18th connected, via the drive power to driven wheels 20L , 20R one with the hybrid powertrain 10 equipped vehicle is distributable.

The hybrid drive train is designed in particular for transverse installation in a vehicle such that axles of the hybrid drive train 10 are aligned transversely to a direction of travel of the vehicle.

The hybrid powertrain 10 is preferably operated automatically. To this end, the hybrid powertrain has 10 a control device 22nd on which a state of the drive train in a known manner 10 sensed and sends control signals to actuators.

The gear arrangement 16 has an input shaft 24 on that on a first axis A1 lies. The gear arrangement 16 further includes an output shaft assembly 25th which may include a single output shaft, but in the present case a first output shaft 26th and a second output shaft arranged axially parallel thereto 28 having. The first output wave 26th is on a second axis A2 arranged. The second output shaft 28 is coaxial with a third axis A3 arranged.

On the first output shaft 26th is a first output gear 30th set. On the second output shaft 28 is a second output gear 32 set. The output gears 30th , 32 are in engagement with an input member of the power distribution device 18th , which can be a mechanical differential. The power distribution facility 18th is coaxial with a fourth axis A4 arranged.

The input shaft 24 and the output shaft assembly 25th are connected to one another via a plurality of wheel sets.

So shows the gear arrangement 16 a first gear set 34 for the forward gears 1 and 2 on. The gear set 34 includes one with the input shaft 24 connected fixed gear and a first idler gear that rotates on the first output shaft 26th is stored and to set up the forward gear 1 serves. The first gear set 34 also includes a further idler gear that meshes with the fixed gear and on the second output shaft 28 is rotatably mounted. The other idler gear is the forward gear 2 assigned.

The gear arrangement 16 also includes a second gear set 36 that the forward gears 3 and 4th assigned. The second gear set 36 includes one with the input shaft 24 connected fixed gear. The fixed gear meshes with a first idler gear on the first output shaft 26th is rotatably mounted and the forward gear 3 is assigned, as well as with another idler gear that is attached to the second output shaft 28 is rotatably mounted and the forward gear 4th assigned.

The gear sets 34 , 36 are each in a gear set level and are each assigned to two forward gear stages, which are each assigned to different output shafts. Consequently, the transmission arrangement 16 Set up four forward gear stages with only two gear set levels and consequently build very compact axially.

Between the gear sets 94 , 36 is a first clutch level 38 arranged. In the first clutch level 38 is a first clutch pack 40 on the first output shaft 26th arranged and the forward gears 1 and 3 assigned. The first clutch package 40 has a clutch D for the forward gear 1 and a clutch F for the forward gear stage 3 on.

It is also in the first clutch level 38 a second clutch pack 42 on the second output shaft 28 arranged and the forward gears 2 and 4th assigned. The second clutch pack 42 has a clutch E for the forward gear 2 and a clutch G for the forward gear 4th on.

The clutch packs each contain two clutch clutches that can be switched alternatively, whereby a neutral position can also be set up, in which neither of the two clutches is closed.

The gear sets 34 , 36 essentially form a first partial transmission 44 the gear arrangement 16 .

The gear arrangement 16 also has a second partial transmission 46 on that of a first electrical machine 50 assigned.

The second partial transmission 46 has a planetary gear set 52 on, which is coaxial with the second axis A2 is arranged.

The planetary gear set 52 shows first link 54 in the form of a ring gear, a second link 56 in the form of a sun gear and a third link 58 in the form of a planet carrier.

The planet carrier 58 , on which a plurality of unspecified planets are rotatably mounted between the sun gear 56 and the ring gear 54 are arranged and with the sun gear 56 and the ring gear 54 are engaged is with the first output shaft 26th non-rotatably connected.

The second partial transmission 46 also has a coupling shaft 60 on that as a hollow shaft around the first output shaft 26th is arranged around. The coupling shaft 60 rotates with the sun gear 56 of the planetary gear set 52 connected.

On the coupling shaft 60 is a third clutch package 61 arranged. The third clutch pack 61 has a clutch A via which the coupling shaft 60 with a housing 68 is connectable. Furthermore, the third clutch pack 61 a clutch B via which the coupling shaft 60 with the ring gear 54 is connectable. The third clutch pack 61 can also set up a neutral position, like the other clutch packs.

More precisely, it is on the coupling shaft 60 a loose wheel 62 rotatably mounted, the non-rotatable with the ring gear 54 is connected and that via the second clutch B with the coupling shaft 60 is connectable.

The first electric machine 50 is coaxial with a fifth axis A5 arranged and aligned axially parallel to the other axes. The first electric machine 50 has a first pinion connected to a rotor thereof 64 on, the one with the idler wheel 62 of the second part of the transmission 46 is engaged. The first pinion 64 and the idler wheel 62 form a wheel set 66 .

The coupling shaft 60 is also via a coupling shift element C with the first partial transmission 44 connectable, in the present case with a loose wheel 34L1 of the wheelset 34 . The idler wheel 34L1 is the forward gear 1 assigned and is rotatable on the first output shaft 26th stored.

The hybrid powertrain 10 further includes a second electrical machine 70 that are coaxial with a sixth axis A6 is arranged, which is arranged axially parallel to the other axes. The second electric machine 70 has a second pinion 72 which is connected to a rotor in front of it. The second pinion 72 is in engagement with a loose wheel 36L3 of the second wheel set36. The idler wheel 36L3 is rotatable on the first output shaft 26th stored and is the forward gear 3 assigned.

The third clutch pack 61 is in a second clutch level 74 arranged. The coupling shifting element C is in a third shifting clutch level 76 arranged.

The arrangement of the individual elements described above is in the axial direction starting from the input of the gear arrangement 16 the following: adjacent to the entrance is the coupling arrangement 14th with the disconnect clutch K0 . In the plane of the coupling arrangement 14th can also be a driven gear set with driven gears 30th , 32 lie. The power distribution facility 18th is preferably on one of the internal combustion engine 12 facing axial side of the clutch assembly 14th facing.

Axially adjacent to the clutch assembly 14th is the gear set level with the second gear set 34 . The following sequence then results in the axial direction: first shift clutch level 38 with the clutch packages 40 , 42 , Gear set level with the first gear set 34 , third shifting clutch level with the coupling shift element C, second shifting clutch level 74 with the third clutch pack 61 , Wheelset level with the wheelset 66 and gear set level with the planetary gear set 52 .

The drive train described above is capable of four internal combustion engine forward gear stages 1 to 4th set up, as well as four purely electric forward gear stages 1 to 4th by means of the second electrical machine 70 . In the four forward gears 1 to 4th A hybrid driving mode can also be set up with the drive power of the second electric machine 70 with drive power of the combustion engine 12 in the first partial transmission 44 is superimposed.

The drive train 10 of the 1 is also able to use two electric forward gears E1 and E2 set up by means of the first electrical machine 50 .

Finally, a so-called power split operation EDA can be set up for the drive power of the internal combustion engine 12 and drive power of the first electric machine 50 in the planetary gear set 52 are superimposed and the superimposed drive power on the first output shaft 26th the output shaft assembly 25th is directed.

The power split operation is detailed in the document DE 10 2013 215 114 A1 described, the disclosure of which is hereby fully referred to for the purpose of describing the power split operation.

In 2 a shift table for the internal combustion engine driving mode and the power split mode EDA is shown.

In all of these cases, the disconnect clutch K0 the clutch assembly 14th closed. In the forward gears 1 to 4th the respectively assigned clutches D to G are closed. The disconnect clutch is in the power split mode K0 and the coupling switching element C is closed. All other switching elements A, B, D to G are open.

The switching elements, such as the separating clutch K0 and the clutches A to G are each designed as non-synchronized, positive-locking shifting elements in the form of claw clutches. The two electrical machines can be synchronized in each case 50 , 70 respectively.

In 3 is a switching table for the two electromotive gear stages E1 and E2 by means of the first electric machine 50 shown. Here is the disconnect clutch K0 open and it is either the clutch A or the clutch B of the third clutch pack 61 closed. Drive power of the first electric machine 50 can consequently in two different ratios on the first output shaft 26th be directed. It goes without saying that in this case additional electromotive drive power by means of the second electrical machine 70 can be provided by, for example, the clutch F or the clutch G is switched.

Furthermore, in 3 a switching table for an electric driving mode by means of the second electric machine 70 shown. Here, depending on the forward gear, one of the clutches E to G is closed, the separating clutch K0 it is open.

Here, too, a power split operation EDA can be set up if the clutch B is closed. In this case, the power of the second electrical machine 70 and the first electric machine 50 in the planetary gear set 52 superimposed. It goes without saying that the clutch F in particular is closed for this purpose. In 3 only C is checked in the lower switching table for EDA. I wonder how power can be superimposed in the planetary gear set here.

With the hybrid powertrain 10 of the 1 so-called serial operation can be set up. Here the drive power is provided by the first electrical machine 50 via the second partial transmission 46 on the output shaft assembly 25th led to set up a purely electric drive. Furthermore, the separating clutch is closed and the internal combustion engine is started, so that internal combustion engine power is provided via the second gear set 36 on the second electric machine 70 can be performed, which is operated as a generator. The second electrical machine consequently charges an electrical energy store of a vehicle, while the first electrical machine 50 takes electrical energy from the same energy store.

Starting from such a purely electric driving mode (be it in series, that is to say with operation of the second electric machine as a generator or not), it is with the hybrid drive train 10 of the 1 possible to implement a transition to a power split operation without interrupting the tractive effort.

This method is consequently based on a purely electric driving mode using the first electrical machine, the coupling switching element C being open and the switching element A being closed. The method includes the steps of first starting the internal combustion engine via the second electrical machine, if it is not already running. Furthermore, the disconnect clutch K0 open if it is closed. The coupling switching element C is then synchronized, specifically by regulating the speed by means of the second electrical machine 70 , in particular to zero speed (since the switching element A to the housing 68 is connected).

Then the coupling switching element C is closed and the second electrical machine 70 is driven in such a way that the switching element A is relieved (instead the coupling switching element C, which is now closed, is loaded).

In the following the switching element A is closed and the separating clutch K0 is synchronized by means of the first and the second electrical machine. For this purpose, the Torque of the first electric machine 50 slightly decreased and if necessary the torque of the second electrical machine 70 slightly increased. During this speed adjustment phase, the power of the second electrical machine increases 70 on, at the same time the output of the first electric machine drops 50 so that the total output remains roughly constant. At very low driving speeds, the first electric machine may 50 rotates backwards and therefore works as a generator. The second electric machine 70 In this phase, however, always works with a motor, if the load case is “pulling operation” as opposed to pushing operation.

After synchronizing the disconnect clutch K0 this is closed so that the EDA service split operation can be set up.

The torque of the second electric machine 70 can then be reduced to zero or even change into a negative range (generator operation) while the torque is applied to the internal combustion engine 12 is preferably increased. In addition, the speed of the internal combustion engine 12 be raised. The torques and speeds of the internal combustion engine 12 and the first electric machine 50 and the second electric machine 70 are set so that the desired drive torque is provided and any desired energy supply to the electrical system is ensured.

During the transition to power split operation, drive energy must come briefly from the battery. However, it is a small amount of energy because the duration is short, for example 2 seconds. The drive energy then comes from the internal combustion engine 12 .

The advantage of the method is that even when the driving speed is already a little higher, the first electric machine 50 during the speed adjustment phase to the planetary gear set 52 contributes most of the drive power and the second electrical machine 70 can therefore be made smaller.

Furthermore, the hybrid powertrain 10 of the 1 A transition from a power split operation to an electric driving operation without interruption of tractive effort is also possible.

• Zunächst wird das von dem Verbrennungsmotor 12 bereitgestellte Drehmoment verringert und die Trennkupplung K0 wird geöffnet. Während des Lastabbaus wird das Stützmoment an dem Sonnenrad 56 des Planetenradsatzes 52 alleine mittels der zweiten elektrischen Maschine 70 aufgebracht. Damit die zweite elektrische Maschine 70 wenig Leistung benötigt, kann vor diesem Vorgang die Drehzahl des Verbrennungsmotors (und damit auch die der zweiten elektrischen Maschine 70) abgesenkt werden.

Here, starting from a situation in which the power split mode is set up, the disconnect clutch K0 is closed, the coupling switching element C is closed and the switching element A is open, the following steps are carried out:

• First of all, this is from the internal combustion engine 12 provided torque is reduced and the disconnect clutch K0 will be opened. During the load reduction, the supporting torque is applied to the sun gear 56 of the planetary gear set 52 solely by means of the second electrical machine 70 upset. With it the second electric machine 70 requires little power, the speed of the combustion engine (and thus also that of the second electrical machine 70 ) can be lowered.

This is followed by a speed adjustment phase in which the electrical machines 50 , 70 be controlled so that the switching element A becomes synchronous (ie, the sun gear 56 is decelerated to zero). For this purpose, the torque of the second electrical machine is preferably reduced somewhat and, if necessary, the torque of the first electrical machine 50 slightly increased. During this speed adjustment phase, the power of the first electrical machine increases 50 , at the same time the output of the second electrical machine drops 70 so that the total output remains roughly constant.

When the synchronous speed is reached on the switching element A, this is closed.

As a result, the torque of the second electrical machine 70 are dismantled, the switching element A is loaded. The actual transition from power split operation to purely electric driving operation by means of the first electric machine 50 is then basically complete. However, it is advisable to carry out the following additional steps, because otherwise the second electrical machine will remain braked and cannot take on any other functions.

Namely, it is advantageous to now open the switching element C without load. Then the second electrical machine is at a standstill 70 again available for other functions. For example, the second electrical machine 70 the disconnect clutch K0 synchronize and the disconnect clutch K0 can be closed so that a serial driving mode can then be set up in which the second electrical machine 70 works as a generator.

The desire for a transition from power-split operation to purely electric driving operation or vice versa can come from an operating strategy that, among other things, the driving performance and the state of charge of the electrical energy storage device are taken into account.

Further embodiments of drive trains, which are comparable with regard to the basic structure, are explained below to the hybrid powertrain 10 of the 1 . The same elements are therefore identified by the same reference symbols. The main differences are explained below.

The first partial transmission 44 does not include spur gear sets, but a second planetary gear set.

In the hybrid drive train of the 4th is the transmission input shaft 24 with the second planetary gear set 80 connected, more precisely with its sun gear 84 . A ring gear 82 of the second planetary gear set 80 is connected to an input member of a clutch pack, its output members G and D with the output shaft assembly 25th or the housing 68 are connected.

The planet carrier 86 of the second planetary gear set 80 is on the one hand with the rotor of the first electrical machine 50 connected. Furthermore, the planet carrier is 86 of the second planetary gear set 80 with the ring gear 54 of the first planetary gear set 52 connected. Its sun gear is with a coupling shaft 60 connected via the third clutch pack 61 either with the housing 68 can be connected (clutch A), or with the output shaft assembly 25th (Clutch B).

The planet carrier 58 of the first planetary gear set 52 is rotationally fixed to the output shaft assembly 25th connected, and is also connected to an output member of a clutch E, which is part of a clutch pack E, F is. An input element of the clutch pack E, F is connected to the transmission input shaft 24 connected. An output member of the second clutch F is with the planet carrier 86 of the second planetary gear set and with the ring gear 54 of the first planetary gear set 52 non-rotatably connected. The coupling shaft 60 and the input shaft 24 can be connected via the coupling switching element C.

With the hybrid powertrain 10 ' of the 4th the different driving operations according to 5 set up, including various forward gears 1 to 3 as 4.1 . to 4.11 . Also two electric speed levels E1 and E2 can be set up, as well as a power split operation in forward drive EDA-V and a power split operation in reverse EDA-R.

Furthermore, the two planetary gear sets 52 , 80 can be used to achieve a particularly large spread (speed levels ZG1 and ZG2).

In the following 6 to 10 further embodiments of hybrid drive trains are described, which generally correspond to the hybrid drive train in terms of structure and mode of operation 10 ' of the 4th correspond. The same elements are therefore identified by the same reference symbols. The main differences are explained below.

With the hybrid powertrain 10 " of the 6 is the transmission input shaft 24 with the planet carrier 86 " of the second planetary gear set 80 " connected. The planet carrier 86 " of the second planetary gear set 80 " is also connected to an input member of a clutch E, the output member of which is connected to the rotor of the first electrical machine 50 connected is.

The rotor of the first electric machine 50 is, as in the previous embodiments, with the ring gear 54 of the first planetary gear set 52 connected.

The sun gear 84 " of the second planetary gear set 80 " is with the case 68 connected. The ring gear 82 " of the second planetary gear set 80 " is connected to a clutch F, the output member of which is connected to the planet carrier 58 of the first planetary gear set 52 connected is. The clutch F is integrated with a clutch D in a clutch pack, the clutch D being the planet carrier 58 of the first planetary gear set 52 if necessary with the transmission input shaft 24 can connect.

A comparable hybrid powertrain is in 7th at 10 "'shown.

In contrast to the hybrid drive train 10 " of the 6 here is the transmission input shaft 24 connected not only to an input member of a clutch E, but also to the input member of the clutch F. The output member of the clutch F is connected to the rotor of the first electrical machine 50 connected. The clutch E is integrated with another clutch D in a clutch pack. An input element of the clutch pack is with the sun gear 84 " of the planetary gear set 80 "' connected. An output member of the clutch D is with the housing 68 connected. The ring gear 82 "' of the second planetary gear set 80 "' is present exclusively and non-rotatably with the planet carrier 58 of the first planetary gear set 52 connected.

With hybrid powertrains 10 " and 10 "' of the 6 and 7th different speed levels can be set up, as shown in 8th is shown. There are various forward gear stages 1, 2.1. up to 2.7 and 3.1 to 3.4, two electric speed levels E1 , E2 and a power split operation in forward gear EDA-V.

In 9 is another embodiment of a hybrid powertrain 10 ^IV shown.

Here is the input shaft 24 with the planet carrier 86 ^IV of the second planetary gear set 80 ^IV connected. The sun gear 84 ^IV is connected to the housing.

The ring gear 82 ^IV of the second planetary gear set 80 ^IV is connected to an input element of a clutch assembly F, C. The switching clutch or the coupling switching element C is on the output side with the coupling shaft 60 connected. The clutch F is on the output side with the planet carrier 58 of the first planetary gear set 52 connected, and with an output member of a further clutch D. An input member of a clutch pack, which contains the clutch D and a clutch E, is with the planetary carrier 86 ^IV of the second planetary gear set 80 ^IV connected. The output member of the clutch E is with the ring gear 54 connected to the first planetary gear set.

In 10 A shift table is shown showing the different with the hybrid powertrain 10 ^IV of the 9 represents adjustable driving operations. As with the embodiment of the 5 and 7th Various forward gear levels can be displayed, as well as two electric speed levels and a power split mode in forward gear. In addition, a ZG gear can be set using the clutches E and C.

In all embodiments, the sun gear is 56 of the first planetary gear set with the coupling shaft 60 connected, which can be connected to the housing via the switching element A, or via the switching element B to the planet carrier 58 .

In all cases there is also the ring gear 54 non-rotatably with the rotor of the first electrical machine 50 connected. The second electrical machine is also in all cases 70 with its rotor with the gearbox input shaft 24 non-rotatably connected.

The planet carrier 58 of the first planetary gear set 52 is in all cases non-rotatably with the output shaft arrangement 25th connected.

In all cases, a coupling switching element C is provided, by means of which the power split operation can be set up, in which the internal combustion engine power and electromotive power in the first planetary gear set 80 are summed up.

With hybrid powertrains 10 ' to 10 ^IV of the 4th to 10 Instead of spur gear sets for setting up gears, the gear arrangement includes a further planetary gear set which can be connected to the first planetary gear set, to the gear input shaft, to the gear output shaft and to a housing, thereby also providing functions of gears of the first sub-transmission 44 to realize.

In fact, the drive trains of the 4th to 10 establish a plurality of forward gear stages, the number of four forward gear stages as in the hybrid powertrain 1 significantly exceed.

In addition, a power split operation can be implemented in all cases. Furthermore, purely electric driving operation can be implemented in all cases, specifically by means of the first electric machine 50 in two different gear steps E1 and E2 .

In addition, serial operation can also be set up in all cases, in which the first electrical machine 50 provides the drive power and in which the second electrical machine 70 by means of the internal combustion engine 12 is operated as a generator with the separating clutch closed K0 , wherein then preferably none of the other clutches except A and B is inserted or closed.

The above too 1 The procedures described are also applied to the drive trains 4th to 10 feasible.

List of reference symbols

10

Hybrid powertrain

12

Internal combustion engine

14th

Clutch assembly

16

Gear arrangement

18th

Power distribution facility

20L / R

driven wheels

22nd

Control device

24

Input shaft

25th

Output shaft assembly

26th

1. Output shaft

28

2. Output shaft

30th

1. Output gear

32

2nd output gear

34

1st gear set ( 1/2 )

34L1

Idler gear of 34 for gear 1 (first coupling link of C)

36

2nd gear set ( 3/4 )

36L3

Idler wheel of 36 for gear step 3

38

1st clutch level

40

1. Clutch package ( 1/3 )

42

2nd clutch package ( 2/4 )

44

1. Partial transmission

46

2. Partial transmission

50

1. electric machine

52

Planetary gear set ( 46 )

54

1st link (ring gear)

56

2nd link (sun gear)

58

3rd link (planet carrier)

60

Coupling shaft ( 46 ) (second coupling link of C)

61

3. Clutch package

62

Idler wheel

64

1st pinion ( 50 )

66

Wheelset ( 62 / 64 )

68

casing

70

2. electric machine

72

2nd pinion ( 70 )

74

2nd clutch level

76

3rd clutch level

80

2. Planetary gear set

82

1st link (ring gear)

84

2nd link (sun gear)

86

3rd link (planet carrier)

K0

Disconnect clutch

A-G

Clutches

A1-A6

axes

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102013215114 A1 [0002, 0036, 0075]

Claims (14)

A method for operating a hybrid drive train (10), the hybrid drive train (10) having an input shaft (24) which is connected to an internal combustion engine via a separating clutch (K0), and having an output shaft arrangement (25), the input shaft (24) and the output shaft arrangement (25) is assigned a first partial transmission (44) in order to be able to set up an internal combustion engine driving mode, the hybrid drive train (10) having a first electrical machine (50) which is driven via a second partial transmission (46 ) is connected to the output shaft arrangement (25) in order to be able to set up a purely electric driving mode, the second partial transmission (46) having a planetary gear set (52) which can be shifted via at least one switching element (A), and the first partial transmission ( 44) and the second partial transmission (46) can be connected to one another via a coupling shift element (C) in such a way that a power split operation (EDA) can be set up, in which the drive power of the internal combustion engine (12) and drive power of the first electric machine (50) are superimposed in the planetary gear set (52) and the superimposed drive power is directed to the output shaft arrangement (25), the hybrid drive train (10) being a second electric machine (70), which is connected to the first sub-transmission (44), and wherein the method based on a purely electric driving mode using the first electric machine (50) and with the coupling switching element (C) and switching element (A) open, the following Comprises steps: - Starting the internal combustion engine (12) via the second electrical machine (70) if the internal combustion engine (12) is not already running, - Open the separating clutch (K0), if it is closed, - Closing the coupling switching element (C) and driving the second electrical machine (70) such that the switching element (A) is relieved, - opening the switching element (A), - Synchronizing the separating clutch (K0) by means of the first and / or the second electrical machine (50, 70), and - Close the separating clutch (K0) so that the power split mode (EDA) is set up. Procedure according to Claim 1 , wherein after the disconnecting clutch (K0) is closed, the torque provided by the second electrical machine (70) is reduced and / or the torque provided by the internal combustion engine (12) is increased. Procedure according to Claim 1 or 2 wherein in the step of synchronizing the separating clutch (K0) the torque provided by the first electrical machine (50) is reduced and the torque provided by the second electrical machine (70) is increased. Method according to one of the Claims 1 to 3 , wherein a member of the planetary gear set (52) can be connected to a housing (68) via the switching element (A), the second electrical machine (70) being regulated to a speed of zero before the step of closing the coupling switching element (C). Method for operating a hybrid drive train (10), wherein the hybrid drive train (10) has an input shaft (24) which is connected to an internal combustion engine (12) via a separating clutch (K0) and has an output shaft arrangement (25), the input shaft (24) and the output shaft arrangement (25) being assigned a first partial transmission (44) in order to be able to set up an internal combustion engine driving mode, the hybrid drive train (10) having a first electrical machine (50) which is connected via a second Sub-transmission (46) is connected to the output shaft arrangement (25) in order to be able to set up a purely electric driving mode, the second sub-transmission (46) having a planetary gear set (52) which can be shifted via at least one switching element (A), and wherein the the first partial transmission (44) and the second partial transmission (46) can be connected to one another via a coupling shift element (C) in such a way that a power split mode can be set up, b ei the drive power of the internal combustion engine (12) and drive power of the first electric machine (50) in the planetary gear set (52) are superimposed and the superimposed drive power is directed to the output shaft arrangement (25), the hybrid drive train (10) being a second electric machine (70), which is connected to the first sub-transmission (44), and wherein the method is based on the power split operation using the first electrical machine (50) and the internal combustion engine (12) and with the disengaging clutch (K0) and with the coupling switching element closed (C) and with the switching element (A) open the following steps: - reducing the torque provided by the internal combustion engine (12), - opening the separating clutch (K0), - Synchronizing the switching element (A) by means of the first electrical machine (50) and / or the second electrical machine (70), and - Closing the switching element (A). Procedure according to Claim 5 wherein, in the step of synchronizing the switching element (A), the torque provided by the second electrical machine (70) is reduced and the torque provided by the first electrical machine (50) is increased. Procedure according to Claim 5 or 6 , the coupling switching element (C) being opened after the switching element (A) is closed. Procedure according to Claim 7 , wherein after the coupling switching element (C) is opened, the separating clutch (K0) is synchronized by means of the second electrical machine (70) and the separating clutch (K0) is closed. Method according to one of the Claims 1 to 8th , wherein a first coupling element (34L1) of the coupling shift element (C) assigned to the first sub-transmission (44) is an idler gear (34L1) of a gear set (34) for a first gear stage (1) of the first sub-transmission (44). Method according to one of the Claims 1 to 9 , wherein the second electrical machine (70) is connected to a gear set (36) for a gear stage (3) of the first partial transmission (44). Method according to one of the Claims 1 to 10 , wherein the separating clutch (K0) and / or the coupling switching element (C) and / or the switching element (A) is or are designed as a form-fitting switching element. Method according to one of the Claims 1 to 11 wherein the hybrid drive train (10) has a plurality of gear sets (34, 36) which connect the input shaft (24) and the output shaft arrangement (25) and form the first partial transmission (44). Method according to one of the Claims 1 to 12 , wherein a first member (54) of the planetary gear set (52) is connected to the first electrical machine (50) and / or wherein a second member (56) of the planetary gear set (52) via the coupling shift element (C) with the first sub-transmission (44 ) is connectable and / or wherein a third member (58) of the planetary gear set (52) is connected to the output shaft arrangement (25). Hybrid drive train, with an input shaft (24) which is connected to an internal combustion engine (12) via a separating clutch (K0), with an output shaft arrangement (25), the input shaft (24) and the output shaft arrangement (25) having a first partial transmission ( 44) is assigned in order to be able to set up an internal combustion engine driving mode, with a first electric machine (50) which is connected to the output shaft arrangement (25) via a second partial transmission (46) in order to be able to set up a purely electric driving mode, the second sub-transmission (46) has a planetary gear set (52) which can be shifted via at least one shift element (A), and wherein the first sub-transmission (44) and the second sub-transmission (46) can be connected to one another via a coupling shift element (C), such as that a power split operation can be set up with the drive power of the internal combustion engine (12) and drive power of the first electrical machine (50) in the planet gear set (52) are superimposed and the superimposed drive power is passed to the output shaft arrangement (25), with a second electrical machine (70), which is connected to the first sub-transmission (44), and with a control device (22) which is set up for this is, a method according to one of the Claims 1 to 13 perform.

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