DE202015000385U1 - motor vehicle - Google Patents

Abstract

A motor vehicle (100) equipped with an internal combustion engine (110), a clutch (148), a particulate filter (505), and an electronic controller (450) adapted to provide a stop during regeneration of the particulate filter (505). Performing a take-off sail strategy that provides for the clutch (148) to be disengaged and the engine (110) to be idled.

Description

TECHNICAL AREA

The present disclosure relates to a motor vehicle equipped with an internal combustion engine, such. As a diesel engine or a gasoline engine, and equipped with an electronic control unit which is adapted to operate the internal combustion engine according to a stop-start sailing strategy.

BACKGROUND

In order to lower the pollutant emissions of the internal combustion engine, the motor vehicles may be provided with an aftertreatment system comprising an exhaust pipe for conveying the exhaust gases from an exhaust manifold of the engine to the external environment and a number of after-treatment devices disposed along the exhaust pipe are to change the composition of the exhaust gases.

The aftertreatment devices may in particular include the following: oxidation catalysts such. As diesel oxidation catalysts (DOC), which are intended to promote the oxidation of hydrocarbons and carbon monoxide, and particulate filter such. B. Diesel Particulate Filter (DPF), which are designed to catch the particulates or soot particles that may be present in the exhaust stream.

Because it works like a filter, the DPF must be periodically cleared of the accumulated particulate matter or soot particles to restore it to its original efficiency.

This process is commonly referred to as regeneration of the DPF and may be carried out by raising the temperature of the exhaust gases to a temperature (eg 600 ° C) capable of promoting combustion of the particulate or soot particles. that have accumulated in the DPF.

To perform this regeneration, the temperature of the exhaust gases may be increased by operating the internal combustion engine in a specific combustion mode that provides for fuel to be injected by so-called late injections into the cylinders of the engine, which are small amounts of fuel at the beginning of the power stroke, into the cylinder of the engine after the piston has passed top dead center (OTP).

The late injections may include secondary injections and / or post-injections. The secondary injections occur prior to opening the exhaust valve so that they have a negligible impact on the torque produced by the engine, but actually burn in the cylinders, thereby increasing the temperature of the exhaust gases. The post injections are made after opening the exhaust valve so that they leave the cylinders unburned and burn in the DOC, producing hot exhaust gases that can heat the downstream DPF.

In order to further reduce the pollutant emissions and the fuel consumption of the internal combustion engine, some motor vehicles can also be operated according to a "stop-start sailing strategy".

The stop-start sailing strategy generally provides that the torque requested by the handlebar is monitored and the vehicle is selectively placed in a "sailing mode of operation" each time the requested torque between the torque required by the vehicle increases At a constant speed, and the torque is, which is consumed by the mechanical friction of the considered alone (ie decoupled from the drive train of the vehicle) internal combustion engine.

After activation, the aforementioned sailing mode of operation conventionally provides for the engine to be decoupled from the driveline, typically by disengaging the clutch, and subsequently stopping rotation of the engine, thereby completely shutting off fuel injection while the motor vehicle is coasting (ie moving through inertia).

However, this conventional sail mode of operation can have a significant impact on the regeneration of the DPF.

In particular, when the sail operating mode is operated during the execution of a DPF regeneration, the engine is shut down and unable to produce the hot exhaust gases necessary to continue regeneration.

In view of the above, an object of an embodiment of the present invention is to coordinate the stop-start sailing strategy with the conventional strategies that control the regeneration of the DPF so that they can be performed simultaneously without causing the above-mentioned side effects.

Another purpose is to achieve the above objectives by a simple, rational and relatively inexpensive solution.

SUMMARY

These and other objects are achieved by the embodiments of the invention as defined in the independent claims. The dependent claims include preferred and / or advantageous aspects of these embodiments.

In particular, an embodiment of the invention provides a motor vehicle equipped with an internal combustion engine, a clutch, a particulate filter, and an electronic control unit configured to perform a stop-start sailing strategy during a regeneration of the particulate filter that provides for the clutch is disengaged and the engine is operated at idle.

Thanks to this solution, the engine is decoupled from the powertrain but not shut down when the DPF regeneration and the stop-start sail strategy are executed simultaneously, so that regeneration of the DPF can continue while the engine is idling.

As a result, the fuel consumption is still significantly reduced, without affecting the efficiency of the DPF regeneration.

However, when the engine is placed in idling, there may be an abrupt decrease in both engine speed and load, thereby decreasing the oxygen (O ₂ ) content of the exhaust gases due to the decrease in engine load (ie, amount of fuel injected) due to the decrease in engine speed and the flow rate of the exhaust gases decreases. This has the following consequences: While the cooling effect caused by the exhaust gases flowing in the DPF decreases, the high oxygen content leads to a considerable promotion of the combustion of soot and particles.

Therefore, if the amount of soot and particulates accumulated in the DPF is still high, typically during the first few moments after the start of regeneration, under these circumstances uncontrolled combustion of the soot may occur, resulting in high temperature gradients and temperature spikes that cause a high level of soot thermal stress on the DPF may result.

Thus, according to one aspect of the invention, the above-mentioned stop-start sailing strategy may include executing a particulate filter protection strategy that provides that a target value for an amount of fuel to be injected into the engine by post-injection be reduced.

In other words, while a target value of the amount of fuel to be injected at each post-injection is determined by a current DPF regeneration strategy, the protection strategy may become active to decrease the target value so that the amount of fuel actually injected by the post-injections is less than the amount requested by the DPF regeneration strategy.

In this way, the temperature of the exhaust gases flowing through the DPF is favorably lowered, and uncontrolled exothermic reactions can be avoided, thereby reducing the thermal stress on the component.

In particular, according to one aspect of the invention, this protection strategy may provide that a predetermined correction offset is subtracted from the target value of the fuel quantity.

This aspect of the invention provides a simple and reliable solution for reducing post-injection fuel quantity.

According to another aspect of the invention, this protection strategy may provide that the target value of the fuel quantity is multiplied by a predetermined correction factor.

This aspect of the invention provides another simple and reliable solution for reducing post-injection fuel quantity.

In accordance with another aspect of the invention, the stop-start sailing strategy may include the implementation of a particulate filter protection strategy that provides that the performance of post-injection be prevented.

In other words, the protection strategy may become active to prevent (eg, with an ON / OFF command) execution of the post-injections that might otherwise be requested by the current DPF regeneration strategy.

In this way, the temperature of the exhaust gases flowing through the DPF is further lowered.

According to another aspect of the invention, the stop-start sailing strategy may include the implementation of a particulate filter protection strategy that provides for recirculation of exhaust gases from an exhaust manifold to an intake manifold of the engine.

Thanks to this solution, the amount of exhaust gas sent back to the intake manifold during regeneration causes the oxygen content and temperature of the exhaust gases exiting the cylinders of the engine to flow through the DPF, causing combustion of the soot and particulate matter in the DPF is made difficult and thus uncontrolled temperature gradients and temperature peaks are avoided.

According to another aspect of the invention, the stop-start sailing strategy may include executing a particulate filter protection strategy that provides for multiple secondary injections to be performed

The in-cylinder combustion of the amounts of fuel injected by these secondary injections causes a portion of the oxygen contained in the combustion air to be consumed, thereby preventing this oxygen from reaching the DPF.

According to one aspect of the invention, the above protection strategy may be performed (and only then) when a temperature of the particulate filter exceeds a predetermined threshold.

This aspect of the invention makes it possible to carry out the protection strategy only if the temperature of the DPF is already high enough to cause the combustion of the particles and of the soot.

According to another aspect of the invention, the protection strategy may be performed (and only then) when a soot amount trapped in the particulate filter exceeds a predetermined threshold.

Thanks to this aspect of the invention, the protection strategy can only be carried out if the amount of soot trapped in the DPF is so high that there is a real possibility that the regeneration will get out of control.

Another embodiment of the invention provides a method of operating a motor vehicle equipped with an internal combustion engine, a clutch, and a particulate filter, the method comprising the step of performing a stop-start sail strategy during regeneration of the particulate filter, which provides the clutch is disengaged and the engine is idling.

This embodiment of the invention achieves substantially the same effect as described above with reference to the motor vehicle, in particular the effect that the stop-start sailing strategy is carried out without affecting the efficiency of the DPF regeneration.

In accordance with one aspect of the invention, the stop-start sailing strategy may include the execution of a particulate filter protection strategy that provides for a target amount of fuel to be injected into the engine by post-injection.

In this way, the temperature of the exhaust gases flowing through the DPF is favorably lowered, and uncontrolled exothermic reactions can be avoided, thereby reducing the thermal stress on the component.

In particular, according to one aspect of the invention, the protection strategy may provide that a predetermined correction offset is subtracted from the target value of the amount of fuel.

This aspect of the invention provides a simple and reliable solution for reducing post-injection fuel quantity.

According to another aspect of the invention, this protection strategy may provide that the target value of the fuel quantity is multiplied by a predetermined correction factor.

This aspect of the invention provides another simple and reliable solution for reducing post-injection fuel quantity.

In accordance with another aspect of the invention, the stop-start sailing strategy may include the implementation of a particulate filter protection strategy that provides that the performance of post-injection be prevented.

In this way, the temperature of the exhaust gases flowing through the DPF is further lowered.

According to another aspect of the invention, the stop-start sailing strategy may include the implementation of a particulate filter protection strategy that provides for recirculation of exhaust gases from an exhaust manifold to an intake manifold of the engine.

The effect of this solution is to reduce the oxygen content and temperature of the exhaust gases exiting the cylinders of the engine and flowing through the DPF, thereby making it difficult to burn the soot and particulate matter in the DPF, thus avoiding uncontrolled temperature gradients and temperature spikes become.

According to another aspect of the invention, the stop-start sailing strategy may include executing a particulate filter protection strategy that provides for multiple secondary injections to be performed.

The in-cylinder combustion of the amounts of fuel injected by these secondary injections causes a portion of the oxygen contained in the combustion air to be consumed, thereby preventing this oxygen from reaching the DPF.

According to one aspect of the invention, the above protection strategy may be performed (and only then) when a temperature of the particulate filter exceeds a predetermined threshold.

This aspect of the invention makes it possible to carry out the protection strategy only if the temperature of the DPF is already high enough to cause the combustion of the particles and of the soot.

According to another aspect of the invention, the protection strategy may be performed (and only then) when a soot amount trapped in the particulate filter exceeds a predetermined threshold.

Thanks to this aspect of the invention, the protection strategy can only be carried out if the amount of soot trapped in the DPF is so high that there is a real possibility that the regeneration will get out of control.

The method according to the invention can be carried out with the aid of a computer program comprising a program code for carrying out all the steps of the method described above, as well as in the form of a computer program product containing the computer program. The method may also be implemented as electromagnetic signals, wherein the signals are modulated to carry a sequence of data bits representing a computer program for performing all steps of the method.

Another embodiment of the invention provides a motor vehicle equipped with an internal combustion engine, a clutch, a particulate filter, and means for performing a stop-start sailing strategy during regeneration of the particulate filter, which provides that the clutch is disengaged and the engine in the Idling is operated.

This embodiment of the invention achieves substantially the same effect as described above with reference to the motor vehicle, in particular the effect that the stop-start sailing strategy is carried out without affecting the efficiency of the DPF regeneration.

According to one aspect of the invention, the means for executing the stop-start sailing strategy may include means for carrying out a particulate filter protection strategy, which provides that a target value of an amount of fuel to be injected into the engine by means of a post-injection is lowered.

In this way, the temperature of the exhaust gases flowing through the DPF is favorably lowered, and uncontrolled exothermic reactions can be avoided, thereby reducing the thermal stress on the component.

According to one aspect of the invention, the means for executing the protection strategy may be configured to subtract a predetermined correction offset from the target value of the amount of fuel.

This aspect of the invention provides a simple and reliable solution for reducing post-injection fuel quantity.

According to another aspect of the invention, the means for executing the protection strategy may be configured to multiply the target value of the fuel amount by a predetermined correction factor.

This aspect of the invention provides another simple and reliable solution for reducing post-injection fuel quantity.

According to another aspect of the invention, the means for executing the stop-start sailing strategy may comprise means for carrying out a particulate filter protection strategy, which provides that the execution of a post-injection is prevented. In this way, the temperature of the exhaust gases flowing through the DPF is further lowered.

According to another aspect of the invention, the means for executing the stop-start sailing strategy may include means for carrying out a particulate filter protection strategy that provides for recirculation of exhaust gases from an exhaust manifold to an intake manifold of the engine.

The effect of this solution is to lower the oxygen content and temperature of the exhaust gases exiting the cylinders of the engine and flowing through the DPF, thereby burning the soot and particulate matter in the DPF is made difficult and thus uncontrolled temperature gradients and temperature peaks are avoided.

According to another aspect of the invention, the means for executing the stop-start sailing strategy may include means for carrying out a particulate filter protection strategy that provides for multiple secondary injections to be performed.

The in-cylinder combustion of the amounts of fuel injected by these secondary injections causes a portion of the oxygen contained in the combustion air to be consumed, thereby preventing this oxygen from reaching the DPF.

According to one aspect of the invention, the means for executing the protection strategy may be configured to execute the protection strategy (and only then) when a temperature of the particulate filter exceeds a predetermined threshold.

This aspect of the invention makes it possible to carry out the protection strategy only if the temperature of the DPF is already high enough to cause the combustion of the particles and of the soot.

According to another aspect of the invention, the means for executing the protection strategy may be configured to execute the protection strategy (and only then) when a soot amount trapped in the particulate filter exceeds a predetermined threshold.

Thanks to this aspect of the invention, the protection strategy can only be carried out if the amount of soot trapped in the DPF is so high that there is a real possibility that the regeneration will get out of control.

BRIEF DESCRIPTION OF THE DRAWINGS

Now, the present invention will be described by way of example with reference to the accompanying drawings.

1 schematically shows a belonging to a motor vehicle drive system.

2 is the cross section AA of a to the drive system of 1 belonging internal combustion engine.

3 is a flowchart illustrating a stop-start sailing strategy for the motor vehicle 1 shows.

4 FIG. 10 is a flow chart showing a protection strategy for a particulate filter associated with the propulsion system of FIG 1 belongs.

PRECISE DESCRIPTION

Some embodiments may be a motor vehicle 100 with a drive system 105 that included in the 1 and 2 is shown and that an internal combustion engine (ICE) 110 with an engine block 120 owns at least one cylinder 125 with a piston 140 defined, which has a coupling with which the crankshaft 145 is turned. The crankshaft 145 may have a coupling with which an axle drive (not shown) of the motor vehicle 100 is rotated, such. B. two or more drive wheels, via a power transmission, the transmission 147 and a clutch 148 may include, which is adapted to the crankshaft 145 selectively with the gearbox 147 to connect or disconnect. The coupling 148 can be actuated by an electric motor (not shown).

A cylinder head 130 works with the piston 140 together to a combustion chamber 150 define. An air-fuel mixture (not shown) enters the combustion chamber 150 introduced and ignited, resulting in hot expanding combustion gases, leading to a reciprocation of the piston 140 to lead. The fuel is from at least one fuel injector 160 provided and the air through at least one inlet 210 , The fuel is under high pressure from a fuel pipe 170 , the fluid zueitend with a high-pressure pump 180 that the pressure of a fuel source 190 increased fuel, is connected to the fuel injector 160 guided. Each of the cylinders 125 has at least two valves 215 coming from a camshaft 135 operated at the same time as the crankshaft 145 rotates. The valves 215 selectively release air from the inlet 210 in the combustion chamber 150 and alternately allow the outlet of the exhaust gases through the outlet 220 , In some examples, a camshaft phasing system 155 used to selectively the timing between the camshaft 135 and the crankshaft 145 to change.

The air can be the air inlets 210 via an intake manifold 200 be supplied. An air inlet pipe 205 leads the intake manifold 200 Ambient air too. In other embodiments, a throttle 330 be selected to control the air flow to the intake manifold 200 to regulate. In other embodiments, a compressed air system such as a turbocharger is used 230 with a compressor 240 that is together with a turbine 250 turns, used. The rotation of the compressor 240 increases the pressure and the Temperature of the air in the inlet pipe 205 and in the intake manifold 200 , One in the inlet pipe 205 containing intercooler 260 can reduce the temperature of the air. The turbine 250 turns when flowing from an exhaust manifold 225 coming exhaust gases, the exhaust gas from the outlet 220 passes through a series of vanes before passing through the turbine 250 is expanded. This example shows a variable geometry turbine (VGT) with a VGT actuator 290 configured to move the vanes to cause the vanes to flow the exhaust gas through the turbine 250 to change. In other embodiments, the turbocharger 230 have a fixed geometry and / or include a wastegate valve. Some embodiments may include an exhaust gas recirculation (EGR) system. 300 with an EGR line 305 include the outlet of the exhaust manifold 225 fluid-conducting with the inlet of the intake manifold 200 connects, whereby a part of the exhaust gas can be mixed with the combustion air. The EGR system 300 may also include one in the EGR line 305 arranged EGR cooler 310 include the temperature of the exhaust gases in the EGR system 300 to lower. It can be an EGR valve 320 be provided to the flow rate of exhaust gases in the EGR pipe 305 to regulate.

Downstream of the turbine 250 the exhaust gases are in an aftertreatment system 270 directed. The aftertreatment system 270 can be an exhaust pipe 275 having one or more exhaust aftertreatment devices. Aftertreatment devices can be any devices with which the composition of the exhaust gases can be changed. Some examples of aftertreatment devices include, but are not limited to, catalytic (two- and three-way) converters, oxidation catalysts, lean NOx traps, hydrocarbon adsorbers, Selective Catalytic Reduction (SCR), and particulate filter.

In the embodiment of 1 includes the aftertreatment system 270 in particular a diesel oxidation catalyst (DOC) 500 in the exhaust pipe 275 near the turbine 250 is arranged, and a diesel particulate filter (DPF) 505 in the exhaust pipe 275 downstream from the DOC 500 is arranged. The DOC 500 and the DPF 505 can be housed in a common housing. A lambda probe 510 and a temperature sensor 515 can in the exhaust pipe 275 between the turbine 250 and the DOC 500 be arranged to the oxygen concentration or the temperature of the exhaust gas at the inlet of the DOC 500 to eat. A second lambda probe 520 and a second temperature sensor 525 can in the case between the DOC 500 and the DPF 505 be arranged to the oxygen concentration or the temperature of the exhaust gas at the inlet of the DPF 505 to eat. A pressure sensor 530 can be provided to reduce the pressure drop in the DPF 505 to eat. A soot sensor 535 can also be in the exhaust pipe 275 downstream from the DPF 505 be arranged to measure the soot concentration in the exhaust gases.

The drive system 105 can still use an electronic control unit (ECM) 450 configured to receive signals from or to various, with the ICE 110 connected sensors and / or devices to send or receive. The ECM 450 It can receive input signals from various sensors designed to generate the signals proportional to various physical parameters associated with the ICE 110 are. The sensors include, but are not limited to, an air mass flow and temperature sensor 340 , a pressure and temperature sensor 350 for the manifold, a sensor 360 for the pressure in the combustion chamber, sensors 380 for the coolant and oil temperature and / or the associated fill level, a pressure sensor 400 for the fuel, a camshaft position sensor 410 , a crankshaft position sensor 420 , a speedometer 430 for measuring the speed of the motor vehicle 100 , an EGR temperature sensor 440 as well as a position sensor 445 for the gas pedal. The sensors also include all the above-mentioned sensors of the aftertreatment system 270 , Furthermore, the ECM 450 to output various signals to control the operation of the ICE 110 to control, for example, to fuel injectors 160 , to the throttle 330 , to the EGR valve 320 , to the VGT actuator 290 , to the actuator of the clutch 148 and to the camshaft adjusting system 155 , It should be noted that dashed lines are used to indicate various connections between the various sensors, devices and the ECM 450 but others have been omitted for purposes of clarity.

The control unit 450 may have a digital microprocessor unit (CPU) data-connected to a memory system and a bus system. The CPU is trained to use commands as one in a storage system 460 stored program are executed to process input signals from the data bus and output signals to the data bus. The storage system 460 can have various storage media such as optical, magnetic, solid state and other non-volatile media. The data bus may be configured to send, receive, and modulate analog and / or digital signals to and from the various sensors and control devices. The program may be arranged to be capable of embodying the methods described herein so that the CPU may perform the steps of such methods and with it the ICE 110 can control. That in the storage system 460 stored program is the control unit from the outside wired or supplied by radio. Outside the drive system 105 it regularly appears on a computer program product, also referred to in the art as a computer or machine readable medium, which is to be understood as a computer program code on a carrier. The wearer may be volatile or non-volatile with the result that one can also speak of a volatile or non-volatile nature of the computer program product.

An example of a volatile computer program product is a signal, such as an electromagnetic signal, such as an optical signal, that is a transient carrier for the computer program code. The carrying of the computer program code can be achieved by modulating the signal with a conventional modulation technique such as QPSK for digital data, so that binary data representing the computer program code is impressed on the volatile electromagnetic signal. Such signals are used, for example, when a computer program code is wirelessly transmitted to a laptop over a WiFi connection.

In the case of a non-transitory computer program product, computer program code is embodied in a substrate-bound storage medium. The storage medium is then the non-volatile carrier referred to above, such that the computer program code is permanently or non-permanently stored in or on the storage medium in a retrievable manner. The storage medium may be of the conventional type known in the field of computer technology, for example a flash memory, an asic, a CD and the like.

Instead of an engine control unit 450 can the drive system 105 have a different type of processor to provide the electronic logic, such as an embedded controller, an on-board computer, or any other type of processor that can be used in a vehicle.

As shown in the flow chart of 3 can be represented, the ECM 450 be designed for the DPF 505 periodically regenerate (block S100). The regeneration of the DPF 505 can be started automatically when in the DPF 505 collected amount of soot exceeds a critical level that can be quantified, for example, at 10 g / l (ie grams of carbon black per liter of DPF).

To perform this regeneration, the ECM 450 be designed to perform a (known per se) DPF regeneration strategy, which serves to increase the temperature of the exhaust gases passing through the DPF 505 flow, causing the DPF 505 is heated to a temperature (eg 600 ° C), which triggers the combustion of the accumulated soot. According to this DPF regeneration strategy, the exhaust gas temperature can be increased by the fuel injectors 160 be operated so that they make a plurality of successive fuel injections (also referred to as injection pulses) per engine cycle according to a predetermined and special multiple injection pattern.

This multiple injection pattern may include a so-called main fuel injection, which is performed just before the piston 140 reached its top dead center (OTP) at the end of the compression stroke. The main fuel injection provides a relatively large amount of fuel to the crankshaft 145 can produce a torque corresponding to the requirements of the driver.

The multiple injection pattern may also include one or more pilot injections during the compression stroke of the piston 140 be performed immediately before the main injection. When the amount of fuel that is provided by each pilot injection, it usually is a small amount of fuel, for example, about 1 mm ^3, which has the effect of the explosive of the main injection and thus the vibration of the engine 110 to reduce.

The multiple injection pattern may also include one or more secondary injections. A secondary injection is a fuel injection into the combustion chamber 150 That is done after the piston 140 at the beginning of the working stroke has reached the top dead center (OTP), but before the opening of the outlet 220 takes place. The amount of fuel provided by a secondary injection, which is normally a small amount (eg, 1 mm ³ ), has a negligible effect on that of the engine 110 generated torque, but burns in the combustion chamber 150 , whereby the temperature of the exhaust gases is increased, after opening the outlet 220 through the exhaust pipe 275 and the aftertreatment system 270 stream.

The multiple injection pattern may also include one or more post-injections. A post-injection is a fuel injection into the combustion chamber 150 after opening the outlet 220 at the end of the working cycle. The quantity of fuel supplied by means of a post-injection, which is normally a small amount (eg 1 mm ³ ), does not burn in the combustion chamber 150 but is unburned by the outlet 220 ejected and flows to the aftertreatment system 270 , In fact, this amount of fuel can flow along the exhaust pipe 275 and / or in the DOC 500 burn, thereby generating hot exhaust gases that can heat these devices and the downstream devices. To carry out these injections, the ECM 450 within the DPF regeneration strategy, determine in real time a target value F _{tar of} the amount of fuel to be injected by each post fuel injection, and then the fuel injectors 160 operate accordingly. The target value F _{tar of} the post-injection fuel amount may be determined based on the engine operating point, that is, based on the current engine speed and engine load values.

The ECM 450 can also be designed for the motor vehicle 100 operate according to a stop-start sailing strategy, which has the purpose of fuel consumption and thus the pollutant emissions of the internal combustion engine 110 to lower (see the flow chart of 3 ).

The stop-start sailing strategy usually provides for determining a value Q _req of torque from the handlebar of the motor vehicle 100 is requested (block S105). The requested torque _value Q _req can be obtained from the ECM 450 based on the position of the accelerator pedal as determined by the sensor 445 is measured.

The requested torque value Q _req is then compared to two thresholds (block S110). A first threshold Q _mot may represent the torque produced by the internal combustion engine (ie decoupled from the powertrain) 110 is consumed due to mechanical friction and pumping losses. A second threshold _Q.sub.rl may stand for the torque produced by the motor vehicle 100 (at the drive wheels) is needed to move at a constant speed.

Each time the torque value Q _{req is} between the first threshold Q _mot and the second threshold Q _rl , the ECM 450 ensure that a sail operating mode is activated (block S115), which is deactivated immediately as soon as the torque value Q _req falls below the first threshold Q _mot or exceeds the second threshold Q _rl . To prevent too frequent activation of the sail operating mode, the second threshold Q _rl may be reduced by a predetermined offset with respect to the torque that is actually necessary to the motor vehicle 100 to drive at a constant speed.

When the sail mode of operation is activated while no DPF regeneration is in progress, the ECM provides 450 traditionally as part of the stop-start sailing strategy for making the clutch 148 is disengaged to the internal combustion engine 110 to decouple from the drive train and immediately after the engine 110 to stop. In this way, no fuel is consumed, and the motor vehicle rolls out.

Conversely, if the sail mode of operation is activated while DPF regeneration is in progress (block S120), the ECM 405 as part of the stop-start sailing strategy, the clutch 148 disengage (block S125) to the internal combustion engine 110 to disconnect from the drive train, and immediately after the engine 110 idle, ie with engine speed and engine load minimums (block S130). While the motor vehicle rolls out, the internal combustion engine is 110 thus still able to make the fuel injections and generate the hot exhaust gases necessary to maintain DPF regeneration.

The ECM 405 In this second case, as part of the stop-start sailing strategy, it can monitor a value S of soot that is still in the DPF 505 is located (block S135), and the Rußmengenwert S with a predetermined threshold value S _th compare (block S140). The soot amount value S can be estimated by means of a (known per se) estimation model, which outputs one in the DPF 505 remaining residue determined. This proportion is referred to as the amount of soot that was originally in the DPF at the beginning of regeneration 505 was caught. The threshold S _th may be a soot amount value above which it is present in the DPF 505 could lead to uncontrolled exothermic reactions. The threshold value S _th may be a calibration parameter that is determined by experiments and / or based on theoretical considerations. For example, the threshold S _{th of} any value may be over 80% residual soot, in particular, it may be set at 85%.

At the same time, as part of the stop-start sailing strategy, the ECM may set a value T of a temperature of the DPF 505 monitor (block S145) and compare this temperature value T with a predetermined threshold value T _th (block S150). The value T of the DPF temperature may be estimated based on the temperature of the exhaust gases at the DPF inlet, as determined by the temperature sensor 525 is measured. The threshold value T _th can be a temperature value below that in the DPF 505 contained soot can not burn, so that it can not come to an uncontrolled exothermic reaction. The threshold value T _th may be a calibration parameter that is determined by experiments and / or based on theoretical considerations. For example, the threshold T _{th may be} any value above 500 ° C, and may be set to 550 ° C or 590 ° C in particular.

When the soot amount value Q exceeds the threshold value Q _th and at the same time the temperature value T exceeds the threshold value T _th (block S155), the ECM 405 Implement a protection strategy designed to protect the DPF as part of the Stop-Start Sail strategy 505 to protect against excessive thermal loads (block S160). After the protection strategy has been activated, it can be executed as long as the above condition is met. If the condition is no longer met, the protection strategy can be disabled, and the regeneration of the DPF 505 can be continued as the current regeneration strategy provides.

As shown schematically in the flow chart of 4 is shown, the ECM 450 as part of the protection strategy, reduce the amount of fuel injected by the post fuel injections (block S165). In other words, the protection strategy may become active to decrease the target value F _{tar of} the post-injection fuel amount determined by the current DPF regeneration strategy so that the amount of fuel actually injected by the post-injections is less than the amount that is requested by the DPF regeneration strategy.

For this, the ECM 450 subtract a predetermined correction offset C from the target value F _{tar of} the post-injection fuel quantity: F _tar = F _tar -C. The correction offset C may be a calibration parameter determined by trial and / or based on theoretical considerations. For example, the correction offset C may be any value between 1 and 2 mm ³ .

As an alternative, the ECM 450 multiply the target value F _{tar of} the post-injection fuel quantity by a predetermined correction factor G: F _tar = F _tar × G. The correction factor G may be a calibration parameter determined by experiments and / or based on theoretical considerations. For example, the correction factor G may be 0.5 or a similar value.

In some embodiments, the ECM 450 Within the scope of the protection strategy, prevent any post-injection entirely. In other words, the protection strategy may become active to prevent execution of the post-injections that might otherwise be requested by the current DPF regeneration strategy. That way, the ECM becomes 450 during execution of the protection strategy, force the fuel into the combustion chambers according to an injection pattern (eg, a multiple injection pattern) that does not include any post-injection 150 inject the engine. This can be done by executing an ON / OFF command that intervenes in the DPF regeneration strategy to selectively activate / deactivate the post-injection, or by selectively setting the correction factor G to zero.

The ECM 450 may, as part of the protection strategy (alternatively or additionally), recirculate exhaust gases from the exhaust manifold 225 to the intake manifold 200 of the motor 110 allow (block S170). To accomplish this return, the ECM 450 be designed for the EGR valve 320 to operate to the EGR line 305 at least partially open, so that the exhaust gases can pass in it. The amount of recirculated exhaust gas may be through the ECM 450 be regulated to the temperature and the oxygen content of the engine 110 to reduce generated exhaust gases accordingly.

The ECM 450 can (as an alternative or in addition) make several secondary injections as part of the protection strategy (block S175). In other words, the protection strategy may provide that the ECM 450 is forced into the combustion chambers according to an injection pattern (eg, a multiple injection pattern) comprising a plurality of secondary injections 150 inject the engine. The in-cylinder combustion of the amounts of fuel injected by these secondary injections consumes a portion of the oxygen contained in the combustion air, thereby reducing the oxygen content of the engine 110 generated exhaust gases is further reduced.

These processes make it possible to burn soot and particles in the DPF 505 To complicate and thus prevent uncontrolled temperature gradients and temperature peaks.

In the foregoing summary and detailed description, at least one exemplary embodiment has been presented; however, it should be noted that there are a large number of modification options. It should also be noted that the exemplary embodiment or exemplary embodiments are only examples and are not intended to limit the scope, applicability, or construction in any way whatsoever. Rather, the foregoing summary and detailed description will provide those skilled in the art with a practical guide to implementing at least one example embodiment, it being understood that various changes may be made in the functions and arrangements of the elements described with reference to an exemplary embodiment without departing from the spirit of the invention Scope of protection as defined in the appended claims and their legal equivalents.

LIST OF REFERENCE NUMBERS

100

motor vehicle

105

drive system

110

internal combustion engine

120

block

125

cylinder

130

cylinder head

135

camshaft

140

piston

145

crankshaft

147

transmission

148

clutch

150

combustion chamber

155

Cam Phaser System

160

fuel injector

170

Fuel pipe

180

Fuel pump

190

Fuel source

200

intake manifold

205

Air inlet tube

210

inlet

215

valves

220

outlet

225

exhaust manifold

230

turbocharger

240

compressor

250

turbine

260

Intercooler

270

aftertreatment system

275

exhaust pipe

290

VGT actuator

300

Exhaust gas recirculation system (EGR)

305

EGR line

310

EGR cooler

320

EGR valve

330

throttle

340

Mass flow and temperature sensor for the air

350

Sensor for manifold pressure and temperature

360

Combustion pressure sensor

380

Sensors for coolant and oil temperature and the associated level

400

Fuel rail pressure sensor

410

Camshaft position sensor

420

Crankshaft position sensor

430

speedometer

440

EGR temperature sensor

445

Accelerator position sensor

450

electronic control unit (ECM)

460

storage system

500

LNT DOC

505

DPF

510

lambda probe

515

temperature sensor

520

lambda probe

525

temperature sensor

530

pressure sensor

535

soot sensor

S100

block

S105

block

S110

block

S120

block

S125

block

S130

block

S135

block

S140

block

S145

block

S150

block

S155

block

S160

block

S165

block

S170

block

S175

block

Claims (9)

Motor vehicle ( 100 ) with an internal combustion engine ( 110 ), a coupling ( 148 ), a particulate filter ( 505 ) and an electronic control unit ( 450 ), which is designed during a regeneration of the particulate filter ( 505 ) to execute a stop-start sailing strategy, which provides that the clutch ( 148 ) and the engine ( 110 ) is operated at idle. Motor vehicle ( 100 ) according to claim 1, wherein the stop-start sailing strategy is to carry out a strategy for protecting the particulate filter ( 505 ), which provides that a target value of an amount of fuel, which by means of a post-injection into the engine ( 110 ) is to be injected. Motor vehicle ( 100 ) according to claim 2, wherein the protection strategy provides that a predetermined correction offset is subtracted from the target value of the amount of fuel. Motor vehicle ( 100 ) according to claim 2, wherein the protection strategy provides that the target value of the fuel quantity is multiplied by a predetermined correction factor. Motor vehicle ( 100 ) according to one of the preceding claims, wherein the stop-start sailing strategy is the execution of a strategy for the protection of the particulate filter ( 505 ), which provides that the execution of a post-injection is prevented. Motor vehicle ( 100 ) according to one of the preceding claims, wherein the stop-start sailing strategy is the execution of a strategy for the protection of the particulate filter ( 505 ), which provides that a recirculation of exhaust gases from a Exhaust manifold ( 225 ) to an intake manifold ( 200 ) of the motor ( 110 ) becomes possible. Motor vehicle ( 100 ) according to one of the preceding claims, wherein the stop-start sailing strategy is the execution of a strategy for the protection of the particulate filter ( 505 ), which provides that multiple secondary injections are performed. Motor vehicle ( 100 ) according to one of claims 2 to 7, wherein the electronic control unit ( 450 ) is designed to execute the protection strategy when a temperature of the particulate filter ( 505 ) exceeds a predetermined threshold. Motor vehicle ( 100 ) according to one of claims 2 to 8, wherein the electronic control unit ( 450 ) is designed to execute the protection strategy when one in the particulate filter ( 505 ) collected amount of soot exceeds a predetermined threshold.

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