EP3535485A1

EP3535485A1 - Method and device for regenerating a particle filter in a motor vehicle with a hybrid drive

Info

Publication number: EP3535485A1
Application number: EP17797264.3A
Authority: EP
Inventors: Florian Zink; Christoph NEE
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2016-11-03
Filing date: 2017-10-25
Publication date: 2019-09-11
Also published as: CN109923293B; US20190301329A1; KR20190069585A; RU2019116742A; CN109923293A; RU2019116742A3; US11306635B2; KR102200839B1; RU2749608C2; DE102016120938A1; WO2018082986A1

Abstract

The invention relates to a method for regenerating a particle filter in the exhaust gas channel of a motor vehicle comprising a hybrid drive consisting of an electric motor and an internal combustion engine. The internal combustion engine is lugged by the electric motor in order to regenerate the particle filter. The internal combustion engine transports oxygen-rich air into the exhaust gas channel, wherein the soot retained in the particle filter is oxidized by the oxygen, and the particle filter can thus be regenerated. The air quantity during the regeneration of the particle filter is controlled by a throttle valve in the air supply of the internal combustion engine in order to allow the particle filter to be regenerated as quickly and efficiently as possible. The invention further relates to a motor vehicle comprising a hybrid drive consisting of an internal combustion engine and an electric motor, wherein the hybrid drive has a controller in order to carry out such a method in order to regenerate the particle filter.

Description

description

Method and device for the regeneration of a particulate filter in a motor vehicle with

hybrid drive

The invention relates to a method and a device for the regeneration of a particulate filter in the exhaust passage of a motor vehicle with a hybrid drive.

The continuous tightening of the exhaust emission legislation places high demands on the vehicle manufacturers, which are solved by appropriate measures for the reduction of the engine raw emissions and by a corresponding exhaust aftertreatment. With the introduction of legislative stage EU6, a limit for a number of particles is prescribed for gasoline engines or vehicles with hybrid drive, which in many cases requires the use of a particulate filter. When driving such a particulate filter is loaded with Ru ß. So that the exhaust back pressure does not increase too much, this particulate filter must be regenerated continuously or periodically. To a thermal oxidation of the im

To carry out particulate filter retained soot with oxygen, a sufficiently high temperature level in conjunction with simultaneously existing oxygen in the exhaust system of the internal combustion engine is necessary. As modern gasoline engines usually without

Excess oxygen can be operated with a stoichiometric combustion air ratio (λ = 1), additional measures are required. One possibility for regeneration of the particulate filter is the introduction of oxygen into the exhaust gas channel in deceleration phases of the exhaust gas

Internal combustion engine, ie in phases in which no fuel is injected and thus an excess of oxygen in the exhaust gas is present. However, such shear phases occur at a

Combustion engine is not always on schedule, but rather random and not controllable, so that the regeneration phase is triggered more often than actually necessary to avoid the risk of excessive loading of the particulate filter and the associated risk of thermal damage to the particulate filter by uncontrolled Ru ßabbrand. In the worst case, such uncontrolled combustion of Ru could lead to burning through of the particle filter and thus to destruction of the particle filter.

From DE 103 40 934 B4 a method for controlling an internal combustion engine is known, wherein between a normal operation and a regeneration operation of In normal operation, the air mass supplied to the internal combustion engine is controlled by an exhaust gas recirculation valve and a throttle valve, and in the regeneration, the exhaust gas recirculation valve is closed and the air mass supplied to the internal combustion engine is controlled exclusively via the throttle valve.

From DE 10 2016 101 105 A1 a method for the regeneration of a particulate filter in a coasting operation of an internal combustion engine is known, wherein the duration of a coasting phase, in which no fuel is injected into the combustion chambers of the internal combustion engine, in

Depending on the temperature of the particulate filter is controlled.

From WO201 1/104459 A1 a method for the regeneration of a particulate filter of an internal combustion engine in a hybrid vehicle is known. The inlet temperature in the particle filter is continuously measured and compared with a first threshold. In this case, a stop of the internal combustion engine is suppressed if the temperature at the entrance of the particulate filter is below this first threshold value. This will be a stop of the

Prevent combustion engine until the temperature at the entrance of the particulate filter is above a second threshold temperature, above which a stop of the

Internal combustion engine is allowed.

From EP 1 197 642 A2 a method for the regeneration of a particulate filter in a hybrid vehicle is known. In this case, the temperature of the exhaust gas is raised by the fact that the load of the internal combustion engine is raised by the internal combustion engine in addition to the drive of the motor vehicle, the battery of the electric motor of the hybrid vehicle charges.

A disadvantage of these solutions, however, is that continue to shear phases of the

Must be serviced internal combustion engine to perform a regeneration of the particulate filter and the particulate filter continues to regenerate more often than actually necessary.

The invention is based on the object, as fast as possible in a hybrid vehicle with a hybrid drive from an internal combustion engine and an electric motor

To allow regeneration of a particulate filter and to enable a smooth restart of the combustion of the internal combustion engine after successful regeneration of the particulate filter. According to the invention the object is achieved by a method for regeneration of the particulate filter in the exhaust passage of a motor vehicle with a hybrid drive from an electric motor and an internal combustion engine, which comprises the following steps:

Operating the motor vehicle in hybrid operation, wherein during operation of the

Internal combustion engine, the exhaust gas of the internal combustion engine is passed through the particle filter,

Determining a loading state of the particulate filter,

Initiating a regeneration of the particulate filter when the loading state of the

Particulate filter has reached a defined maximum loading condition,

Performing a regeneration process of the particulate filter, wherein the

Combustion engine and the electric motor are coupled during regeneration and the electric motor towed the internal combustion engine, wherein

the internal combustion engine promotes air into the exhaust passage to oxidize the Ru particles retained in the particulate filter, and wherein

a throttle valve of the air supply of the internal combustion engine during the

Regeneration of the particulate filter independent of a torque request of the

Driver is controlled by the hybrid drive.

As a result, efficient deceleration phases of the internal combustion engine are possible, which can be made active by the torque of the electric motor. Thus, it is not necessary to wait for a drive-related overrun phase in order to initiate a regeneration, so that rarer regeneration processes of the particulate filter are necessary. In a motor vehicle with hybrid drive, therefore, a regeneration phase of the particulate filter can be initiated when the particulate filter has reached a defined maximum load condition. Under one

Thrust phase is to be understood in this context an operating state in which no fuel is injected into one of the combustion chambers of the internal combustion engine and the

Internal combustion engine does not deliver drive torque to the crankshaft. Dragging of the internal combustion engine in this context means an operating state in which the electric motor has to apply a torque for rotating the internal combustion engine. In this case, the internal combustion engine is rotated at a speed of greater than 100 U / min, preferably of at least 600 U / min, and preferably the injection of fuel into the

Combustion chambers of the combustion engine completely hidden. Since the internal combustion engine is towed by the electric motor during the regeneration of the particulate filter, the internal combustion engine is used during the regeneration, which for the regeneration of the

Particulate filter necessary to promote oxygen in the exhaust duct. By controlling the throttle regardless of the load request can thus through the throttle the amount of oxygen required for optimal regeneration is supplied to the particulate filter. By a wide opening of the throttle, a rapid regeneration of the particulate filter can be achieved by closing the throttle valve, the air supply is reduced and an uncontrolled Rußabbrand on the particulate filter, which leads to the destruction of the

Particulate filter can be prevented. Thus, compared to an uncontrolled

Regeneration with closed throttle a much faster and more effective

Regeneration of the particulate filter can be achieved, whereby the drag phase of the electric motor can be kept shorter and the motor vehicle can be operated faster in a normal operation.

The measures specified in the dependent claims are advantageous

Improvements and further developments of the method specified in the independent claim for the regeneration of the particulate filter possible.

In a preferred embodiment of the method it is provided that the throttle valve is closed at the end of the regeneration of the particulate filter. By closing the throttle at the end of the regeneration, a negative pressure in the intake of the

Engine generated to allow a restart of the engine with low power output. This is a particularly gentle coupling of the

Internal combustion engine possible, whereby the ride comfort of the motor vehicle is increased.

In a preferred embodiment of the invention, it is provided that the throttle valve is brought into a defined position at the beginning of the regeneration. To a defined

To start regeneration process of the particulate filter, it is advantageous if the throttle valve is brought into a defined position at the beginning of the regeneration, that is, if the opening angle of the throttle valve is fixed at the beginning of the regeneration.

It is particularly preferred if the opening angle of the throttle valve at the beginning of the regeneration of the particulate filter is between 30 ° and 70 °. In order to allow rapid regeneration of the particulate filter without the risk of uncontrolled Ru blast burn and thermal destruction of the particulate filter, it is advantageous to begin the regeneration process with a partially open throttle. In this case, opening angles between 30 ° and 70 ° have been found to be particularly useful because they represent a good compromise between a sufficiently fast regeneration and a limitation of the oxygen supply to the particulate filter. According to an advantageous embodiment of the method it is provided that the

Throttle is closed in discrete steps. One possibility for carrying out the method according to the invention is to transfer the throttle valve in discrete steps from an at least partially closed initial state into a substantially closed final state. In this case, the steps can be selected as a function of a progress of the regeneration of the particulate filter or as a function of the temperature prevailing at the particulate filter.

In a further advantageous embodiment of the method it is provided that the opening angle of the throttle valve is reduced continuously and steadily from the beginning of the regeneration to the end of the regeneration of the particulate filter. By a continuous closing of the throttle valve is the particle filter at the beginning of the regeneration first a

supplied comparatively large amount of oxygen, making it a quick

Rußabbrand on the particulate filter comes. In this case, an uncontrolled increase in temperature above a critical temperature can be prevented by closing the throttle. In addition, a negative pressure in the intake tract of the internal combustion engine is generated by the closing of the throttle valve before a restart of the internal combustion engine, whereby a gentle restart of the internal combustion engine and a corresponding

Power input of the drive power of the internal combustion engine in the drive train of the hybrid vehicle are possible. Thus, a sudden re-insertion of the

Prevent internal combustion engine, whereby the ride comfort and durability of the drive train can be increased.

It is particularly preferred if the closing of the throttle during the

Regeneration of the particulate filter in response to a temperature and / or a Ru ßload of the particulate filter takes place. By changing the opening angle of the throttle valve as a function of the temperature and / or the loading of the particulate filter, a particularly rapid regeneration of the particulate filter without the risk of thermal damage of the particulate filter can be performed.

In a preferred embodiment of the invention, it is provided that the regeneration process is preceded by a heating process in which the particle filter is heated to a temperature range necessary for the oxidation of the soot. Since the overrun operation is usually associated with a decrease in temperature in the exhaust passage, it may be necessary to initiate the regeneration of the exhaust passage and thus the particulate filter on a

Heating regeneration temperature. As for the regeneration of the particulate filter both a sufficiently high temperature level and an excess of oxygen in the exhaust duct are necessary, such a heating phase is a simple and proven means to the

To reach temperature level. The oxygen excess is achieved as shown by the towing operation of the internal combustion engine, wherein the internal combustion engine promotes air in the exhaust passage.

It is particularly preferred if the regeneration of the particulate filter takes place in several steps, wherein alternately switching between a heating phase and a regeneration phase. If a complete regeneration of the particulate filter in a deceleration phase is not possible, in particular because the exhaust gas temperature falls below the lower threshold value, then a multi-stage regeneration of the particulate filter is provided, in which alternately a switchover takes place between a heating phase and a regeneration phase of the particulate filter. In this case, the internal combustion engine is connected both in the heating phase and in the regeneration phase with the drive train of the motor vehicle. In the

Heating phases, the internal combustion engine turns of its own accord, in the

Regeneration phases, the internal combustion engine is towed by the electric motor and thus rotated. Thus, an engine standstill and a decoupling of

Internal combustion engine of the electric motor in the entire regeneration phase

prevented. Through several regeneration steps, a complete regeneration of the particulate filter can be achieved.

According to an advantageous further development of the method it is provided that the

Internal combustion engine during the heating phase with a stoichiometric

Combustion air ratio is operated. At a stoichiometric

Combustion air ratio is a particularly good implementation of pollutants on a particulate filter upstream three-way catalyst possible. There is also a

Stoichiometric combustion air ratio of the internal combustion engine particularly well suited to heat the exhaust gas, since a lean combustion air ratio is usually accompanied by a decreasing power of the internal combustion engine and a rich

Combustion air ratio usually to a cooling of the exhaust gas through the

unburned fuel leads.

In a preferred embodiment of the method it is provided that a load point of the internal combustion engine is displaced during the heating phase such that the

In addition, the internal combustion engine must apply more load by charging the battery. Thus, the load is increased in the heating phase, without the drive torque propulsive. Thereby, the exhaust gas and thus the particulate filter is heated faster under otherwise identical conditions (such as vehicle speed, engine speed) than in a motor vehicle, which has only one internal combustion engine and is driven by this.

In a further preferred embodiment of the invention it is provided that is throttled with the throttle and the engine even with currently running but still

incomplete regeneration of the particulate filter is transferred from the towing operation in the drive mode when the load request to the hybrid drive a certain

Threshold, in particular the rated power of the electric motor exceeds. If a load is requested during the regeneration, which is above the rated load of the electric motor, the regeneration process of the particulate filter can be interrupted in order to provide the maximum system power from the internal combustion engine and the electric motor. Here, the regeneration of the particulate filter is suppressed until the system performance is below the threshold again, and the necessary drive torque and the

Drag torque of the engine can be generated by the electric motor. Due to the multi-stage regeneration of the particulate filter, it is possible to provide the entire system performance at short notice, without the damage of the particulate filter by overcharging and thus a later uncontrolled Ru ßabbrand are to be feared.

In a preferred embodiment, it is provided that the load point of the electric motor is displaced during the regeneration of the particulate filter such that the electric motor applies the driver's desired torque and additionally tows the internal combustion engine. As a result, additional power can be provided by the electric motor during the regeneration of the particulate filter, so that the regeneration process can take place without any restrictions on the driving experience.

It is particularly preferred if the regeneration of the particulate filter is torque-neutral for the propulsion-effective drive torque of the motor vehicle, that is, if the electric motor during regeneration of the particulate filter just as much additional

Provides torque as necessary to tow the internal combustion engine. As a result, the regeneration phases can be carried out particularly comfortably and virtually unnoticed for the driver of the motor vehicle. It finds a full compensation of that

Schleppmomentes instead, which by the friction of the unfired

Verbrennunskraftmasschine is introduced into the drive train. In a further preferred embodiment of the invention, it is provided that the method is carried out in a spark-ignited internal combustion engine. The proposed method is in principle feasible in hybrid vehicles with a self-igniting internal combustion engine as well as in a spark-ignition internal combustion engine. As self-igniting

Internal combustion engines according to the diesel method, however, usually with a

appropriate oxygen excess operated, provides the provision of

However, oxygen for the regeneration of the particulate filter in a diesel hybrid is a small challenge dar. In a gasoline hybrid, which is usually with a

stoichiometric combustion air ratio is operated, however, are additional

Measures to introduce oxygen into the exhaust duct necessary to regenerate the particulate filter. Since a spark-ignition internal combustion engine can not be operated without restrictions on performance, exhaust behavior and / or comfort with a lean combustion air ratio, the proposed method offers the advantage that a

Regeneration especially at middle and lower part loads, as they

For example, occur in a city traffic operation is possible.

According to the invention, a control device for a motor vehicle with a hybrid drive is also proposed, with which such a method can be performed. About such a controller, the power distribution between the electric motor and the engine can be controlled in a simple manner and thus the conditions for carrying out such a method can be created.

According to the invention, a motor vehicle with a hybrid drive, comprising an electric motor and an internal combustion engine, is also proposed, wherein in the exhaust duct of the

Internal combustion engine, a particle filter is arranged, and which is a control device for

Control of the internal combustion engine and the electric motor, wherein the electric motor towed the internal combustion engine during the regeneration of the particulate filter and the

Internal combustion engine promotes air to oxidize the retained in the particulate filter Ru ßpartikel in the exhaust passage. In such a motor vehicle, a particularly fast and efficient regeneration of the particulate filter is possible without this regeneration being noticeably associated with a loss of comfort or power for the driver.

Further preferred embodiments of the invention will become apparent from the remaining, mentioned in the dependent claims characteristics. The various embodiments of the invention mentioned in this application are, unless otherwise stated in the individual case, advantageously combinable with each other.

The invention is described below in embodiments with reference to the associated

Drawings explained. Show it:

1 shows a first embodiment of a motor vehicle according to the invention with a hybrid drive of internal combustion engine and electric motor;

Figure 2 shows another embodiment of a motor vehicle according to the invention with a hybrid drive;

3 shows a first flow chart of a method according to the invention for

Regeneration of a particulate filter in a motor vehicle with hybrid drive; and

FIG. 4 shows a further flow diagram of a method according to the invention for

Regeneration of a particulate filter in a motor vehicle with hybrid drive.

FIG. 1 shows a schematic representation of a motor vehicle 1 with a hybrid drive 2. The hybrid drive 2 comprises an internal combustion engine 10 and an electric motor 20, which can both come into operative connection with a common transmission 46 via a drive train 26. The internal combustion engine 10 is connected to an air supply 30 on the inlet side. In this case, the air supply 30 in the flow direction of fresh air, an air filter 32, downstream of the air filter 32 an air mass meter 38, further downstream a compressor 36 of a turbocharger 40 and a throttle valve 34. Of the

Internal combustion engine 10 is connected on the outlet side to an exhaust gas duct 12, in which a turbine 18, which is connected via a shaft to the compressor 36 of the turbocharger 40, is arranged in the flow direction of an exhaust gas. Downstream of the turbine 18 is a catalyst 14 and further downstream a particulate filter 16 is disposed. The transmission 46 can be connected to the engine 10 via a first clutch 48 and to the electric motor 20 via a second clutch 50. In this case, the internal combustion engine 10 and the electric motor 20 either individually, or together drive the motor vehicle 1. For this purpose, the internal combustion engine 10 via the transmission 46 with a first drive axle of the motor vehicle 1 and the electric motor 20 with a second drive axle 44 of the

Motor vehicle 1 connected. The electric motor 20 is connected to a battery 22, which the electric motor 20 is powered. The electric motor 20 and the internal combustion engine are connected via signal lines 28 to a control unit 10 of the hybrid drive 2, which passes on the driver's power requirements to the two drive motors 10, 20.

Alternatively, the hybrid drive 2 can also be designed with a naturally aspirated engine, in which case the turbocharger 40 with the compressor 36 and the turbine 18 is omitted.

FIG. 2 shows a further exemplary embodiment of a motor vehicle 1 according to the invention with hybrid drive 2. The internal combustion engine 10 and the electric motor 20 are preferably transverse to the direction of travel of the motor vehicle 1 in an engine compartment in

Front of the vehicle arranged. Alternatively, the internal combustion engine 10 and the electric motor 20 may also be arranged longitudinally to the direction of travel. Between the

Internal combustion engine 10 and the transmission 46, a first clutch 48 is arranged, via which the internal combustion engine 10 can be mechanically connected to the transmission 46. This first clutch 48 may be formed both as a simple clutch and as, preferably automated, dual clutch. Between the gear 46 and the

Electric motor 20, a further clutch 50 is provided, which is a coupling

or decoupling of the electric motor 20 allows.

In the rear of the vehicle a tank for the internal combustion engine 10 and a battery 22 for the electric motor 20 are arranged in order to achieve a uniform weight distribution between the first drive axle 42, preferably the front axle of the motor vehicle 1 and the second axle, preferably the rear axle. Alternatively, the tank and / or the battery 22 may also be arranged at other positions of the motor vehicle 1.

The internal combustion engine 10 has an air supply 30, in which an air filter 32 and downstream of the air filter 32, an air mass meter 38 are arranged in the flow direction of the fresh air. Alternatively, the air mass meter 38, in particular a

Hot film air mass meter, also be integrated into the air filter 32. Downstream of the

Air mass meter 38, a throttle valve 34 is arranged, with which the air supply to the combustion chambers of the internal combustion engine 10 can be controlled.

The electric motor 20 and the internal combustion engine 10 are connected via a common

Drive train 26 connected to each other, wherein the connection can be made by the couplings 48 and 50 or prevented. By closing only one of the clutches 48 or 50, the motor vehicle 1 can optionally be operated exclusively electrically, by the electric motor 20 or exclusively with the internal combustion engine 10. are both clutches 48 and 50 closed, so can a boost operation with both drive units 10, 20, a recuperation, so charging the battery 22 of the

Electric motor 20, or an electric braking operation are performed. The transmission 46 is connected to a differential, which via drive shafts, the wheels of the first

Drive axle 42, in particular the front axle, drives.

The internal combustion engine 10 has an exhaust gas channel 12, in which a three-way catalytic converter 14 and a particle filter 16 are arranged. To control the

Internal combustion engine 10 and the electric motor 20, a control unit 24 is provided, which is connected via first signal lines 28 to the engine 10 and via second signal lines 28 to the electric motor 20.

In normal operation, the motor vehicle 1 is operated in a hybrid mode, in which the driver's desired torque for a particular drive motor 10, 20 by the controller 24 to the engine 10, the electric motor 20 or both motors 10, 20 is passed. The stored in the control unit 24 operating strategy of the hybrid drive 2 specifies how the driver's request is met. In this case, the drive torque can either be provided completely by the electric motor 20, be carried out by a division between the electric motor 20 and the internal combustion engine 10 or completely through the

Internal combustion engine 10 take place. In hybrid operation, it is also possible that the

Internal combustion engine 10 generates more torque than is necessary for driving the motor vehicle, wherein the additional torque is used by the coupling of the electric motor 20 via the clutch 50 to charge the battery 22 of the electric motor 20.

While the internal combustion engine 10 is active, the exhaust gas of the internal combustion engine is passed through the particulate filter 16 in the exhaust passage 12. During hybrid operation, the

Particle filter 16 loaded with Ru ßpartikeln until a maximum allowable loading condition of the particulate filter 16 is reached.

FIG. 3 shows a flow chart for the regeneration of the particle filter 16. In a first phase I, the motor vehicle is operated in a hybrid mode I until the particle filter 16 has reached a maximum permissible load state. The opening angle α of the throttle valve 34 is variable between 0% and 100% and depends on the

Power requirement to the internal combustion engine 10. The maximum permissible

Charging state can by a differential pressure measurement on the particulate filter 16 or by modeling the Ru ßeintrags and Ru ßaustrags from the particulate filter 16 by means of a stored in the control unit 24 calculation model can be determined. If the need for regeneration of the particulate filter 16 is determined, the particulate filter 16 is heated to a temperature necessary for regeneration in a second phase II. The heating phase II of the particulate filter 16 is followed by the regeneration phase III of the particulate filter 16. The regeneration phase III of the particulate filter 16 may as shown in Figure 4 in multiple steps to Uli lll ₅ or as shown in Figure 3 are continuous. In Figure 4, a regeneration with five regeneration steps is shown, but it is also

Regenerations with more or less regeneration steps possible. In addition, the heating phase II can be omitted if the particulate filter 16 already at the initiation of the regeneration phase III for the oxidation of the retained in the particulate filter 16 Ru ßes necessary temperature. In the heating phase II, the internal combustion engine 10 is operated with load until an upper threshold temperature T _is reached. This upper threshold temperature is for example at 750 'Ό, whereby ideal conditions for the oxidation of the retained in the particulate filter 16 Ru ßes be created. The heating phase II can, for example, an adjustment of the ignition timing in the direction of late and / or an additional load of the

Internal combustion engine 10 by a generator operation of the electric motor 10 include. In this case, the internal combustion engine 10 is preferably provided with a stoichiometric

Operated combustion air ratio. When the upper threshold temperature T _S o is reached, the fuel injection into the combustion chambers of the engine 10 is stopped and the engine 10 is dragged by the electric motor 20. In this regeneration phase III, the internal combustion engine 10 is rotated by the electric motor 20, wherein the

Internal combustion engine 10 promotes air into the exhaust passage 12. During the regeneration phase III, which represents a coasting phase for the internal combustion engine 10, the soot in the particulate filter 16 is oxidized, whereby the absence of combustion in the combustion chambers of the

Internal combustion engine 10, the exhaust gas temperature drops. In this case, alternatively, the injection of fuel into individual or all cylinders of the internal combustion engine 10 can be hidden. During the regeneration phase III, the internal combustion engine 10 does not supply any drive torque, so that the entire drive torque has to be generated by the electric motor 20. In this case, the opening angle α of the throttle valve 34 at the beginning of the regeneration of the particulate filter 16 to a fixed value, for example, set 50% and it takes place during the regeneration of the particulate filter 16, a continuous closing of the throttle valve 34 until the completion of regeneration an opening angle α of the throttle 34 of 0%, that is, a maximum throttling of the fresh air amount is reached. The regeneration phase 3 is as long

maintained until the temperature at the particulate filter 16 reaches a lower threshold T _S u of about 600 'Ό. Below this temperature, no further oxidation of the Ru ßes longer possible, so again a heating phase II must be initiated. For the regeneration of the Particulate filter 16 can alternately be changed between the heating phase II and a regeneration phase III 3. This alternating change between heating phase II and

Regeneration phase III is repeated until the particle filter 16 can be regarded as regenerated, which can be done by a differential pressure measurement via the particle filter 16 or by modeling the loading state via a calculation model. By closing the throttle valve 34 to the end of the regeneration III is in the intake passage of the internal combustion engine 10 before a negative pressure, which is a particularly gentle

Restoring combustion in the combustion chambers of the internal combustion engine 10

allows.

After a successful regeneration of the particulate filter 16, the motor vehicle is operated again in a hybrid mode I and the particulate filter 16 is loaded again with soot particles.

FIG. 4 shows a further scheme for the regeneration of the particulate filter 16. In substantially the same procedure as described for Figure 3, the closing of the

Throttle 34 here in discrete steps, for example, by 10% per step. In this case, the throttle valve 34 is at the beginning of the regeneration Uli of the particulate filter 16 with a defined, set opening angle α of, for example, 60% open, with each further step lll ₂ to lll _5, the throttle valve 34 is further closed by a defined proportion, until it Completion of the regeneration of the particulate filter 16 is at least substantially closed and has a maximum residual opening of 10%.

During the regeneration of the particulate filter 16, a load request to the

Hybrid drive 2, which exceeds the power of the electric motor 20, the throttle valve 34 is closed to facilitate commissioning of the internal combustion engine 10. In this case, the regeneration phase III of the particulate filter 16 is interrupted until again suitable conditions for a regeneration of the particulate filter 16 are present.

By the method according to the invention a particularly efficient mechanism for burning off Ru ßpartikeln on the particulate filter 16 is created. By the towing operation of the internal combustion engine 10 by the electric motor 20, the entry of oxygen into the exhaust passage 12 is largely freely controlled by the load point of the hybrid drive 2. The torque necessary for towing the internal combustion engine 10 is generated by the electric motor 20, so that the regeneration of the particulate filter 16 is imperceptible and particularly comfortable for the driver of the motor vehicle 1. To optimize the regeneration, as described, both the load point of the

Internal combustion engine 10 (in particular in the heating phase II) and the load point of the electric motor 20 are moved in the overrun phase. In this case, the internal combustion engine 10 is not decoupled from the drive train of the motor vehicle 1 with hybrid drive 2 during regeneration. This results in a significantly simple regeneration option for the particle filter 16.

LIST OF REFERENCE NUMBERS

1 motor vehicle

hybrid drive

10 internal combustion engine

12 exhaust duct

14 catalyst

16 particle filters

18 turbine

20 electric motor

22 battery

24 control unit

26 powertrain

28 signal line

30 air supply

32 air filters

34 throttle

36 compressors

38 air mass meter

40 turbochargers

42 first drive axle

44 second drive axle

46 gearbox

48 first clutch

50 second clutch

S Soot loading of the particulate filter

P Progress of the particle filter regeneration

t time

α opening angle of the throttle valve a _F ix Opening angle during regeneration predefined by method

I hybrid operation

II heating phase of the particulate filter

III regeneration phase of the particulate filter

Uli first step of regeneration

second step of regeneration

third step of regeneration

NU fourth step of regeneration

Iiis fifth step of regeneration

Claims

claims

1 . Process for the regeneration of a particulate filter (16) in the exhaust gas duct (12) of a

Motor vehicle with a hybrid drive from an electric motor (20) and a

Internal combustion engine (10), comprising the following steps:

Internal combustion engine (10), the exhaust gas of the internal combustion engine (10) through the particulate filter (16) is passed,

Determining a loading state of the particulate filter (16),

Initiating regeneration of the particulate filter (16) when the load condition of the particulate filter (16) has reached a defined maximum load condition,

Performing a regeneration process of the particulate filter (16), wherein the

Combustion engine (10) and the electric motor (20) are coupled during the regeneration and the electric motor (20) trailing the internal combustion engine (10), wherein

the internal combustion engine (10) conveys air into the exhaust passage (12) to oxidize the Ru particles retained in the particulate filter (16), and wherein a throttle valve of the air supply of the internal combustion engine (10) during the regeneration of the particulate filter (16) independently

Torque request of the driver is controlled to the hybrid drive.

2. The method according to claim 1, characterized in that the throttle valve for

End of the regeneration of the particulate filter (16) is closed.

3. The method according to claim 1 or 2, characterized in that the throttle valve is brought to the beginning of the regeneration of the particulate filter (16) in a defined position.

4. The method according to claim 3, characterized in that the opening angle of the throttle at the beginning of the regeneration a significantly Entschrosselten operating point, preferably between 30 ° and 70 ° opening angle represents.

5. The method according to any one of claims 1 to 4, characterized in that the opening angle of the throttle valve from the beginning of the regeneration to the end of

Regeneration is continuously and steadily reduced.

6. The method according to claim 5, characterized in that the reduction of

Opening angle of the throttle during the regeneration of the particulate filter (16) in response to a temperature and / or a loading state of the particulate filter (16).

7. The method according to any one of claims 1 to 6, characterized in that the

Regeneration process is preceded by a heating process in which the particulate filter (16) is heated to a temperature range necessary for the oxidation of the soot.

8. The method according to claim 7, characterized in that the internal combustion engine (10) is operated during the heating phase with a stoichiometric combustion air ratio.

9. The method according to any one of claims 7 or 8, characterized in that a

Load point of the internal combustion engine (10) is shifted in the heating phase such that the internal combustion engine (10) by applying a charge to the battery (22) against the work of the electric motor (20) must apply additional load.

10. The method according to any one of claims 1 to 9, characterized in that the

Throttle closed and the internal combustion engine (10) is started even with incomplete regeneration of the particulate filter (16) when the load request to the hybrid drive exceeds a certain threshold.

1 1. Method according to one of claims 1 to 9, characterized in that a

Load point of the electric motor is displaced during the regeneration of the particulate filter such that only the electric motor applies the driver's desired torque for the motor vehicle and in addition the internal combustion engine (10) drags.

12. The method according to claim 1 1, characterized in that the regeneration of

Particle filter (16) torque neutral for the propulsive drive torque of the motor vehicle takes place.

13. The method according to any one of claims 1 to 12, characterized in that the method is carried out on a spark-ignited internal combustion engine.

14. Control device for a motor vehicle with a hybrid drive from a

An internal combustion engine (10) and an electric motor (20) arranged to perform a method according to any one of claims 1 to 13.

15. Motor vehicle with a hybrid drive, comprising an electric motor (20) and an internal combustion engine (10), wherein in an exhaust passage (12) of the internal combustion engine (10) a particulate filter (16) is arranged, and at least one control device for controlling the internal combustion engine ( 10) and the electric motor (20), wherein the electric motor (20) drags the internal combustion engine during the regeneration of the particulate filter (16) and the internal combustion engine (10) air for oxidation of Ru in the particulate filter (16) retained Ru particles in the exhaust passage (12). promotes, the

Internal combustion engine (10) comprises an air supply system in which a

Throttle valve for controlling the internal combustion engine (10) supplied amount of air is arranged.