WO2009103590A1

WO2009103590A1 - Method and device for controlling a compressed air supply of an internal combustion engine and other devices

Info

Publication number: WO2009103590A1
Application number: PCT/EP2009/050824
Authority: WO
Inventors: Christoph RÜCHARDT; Thomas JÄGER; Roland Mair
Original assignee: Zf Friedrichshafen Ag
Priority date: 2008-02-18
Filing date: 2009-01-26
Publication date: 2009-08-27
Also published as: DE102008000325A1

Abstract

The invention relates to a method for operating an automotive drive train (1) comprising an internal combustion engine (2), a turbocharger (22) associated with said internal combustion engine, and a device for injecting additional compressed air into devices in the region of the internal combustion engine (2). The aim of the invention is to reduce the exhaust emissions and the fuel consumption of the internal combustion engine (2) of a vehicle that is equipped with the above components. The method according to the invention is characterized in that additional compressed air is injected into devices (8, 100) in the region of the internal combustion engine (2) if this injection leads, depending on the actual operating situation of the vehicle, to an advantageous operating behavior of the internal combustion engine (2) and/or of vehicle devices that are arranged in the exhaust gas flow of said internal combustion engine. The invention further relates to a device for carrying out said method, the device for injecting additional compressed air being designed and arranged in such a manner that it can inject compressed air into the air intake system (8) and directly upstream of or into the exhaust gas treatment system (100) of the internal combustion engine (2).

Description

Method and device for controlling a Druckluftversorqunq an internal combustion engine and other devices

The invention relates to a method and a device for operating a vehicle drive train with an internal combustion engine, with a turbocharger associated with this internal combustion engine, with a device for injecting additional compressed air in facilities in the field of the internal combustion engine and with an exhaust treatment plant and a starter.

For example, from the patent applications WO 2006/037564 A1, WO 2006/089779 A1 and WO 2006/089780 A1, it is known that a piston internal combustion engine equipped with a turbocharger delivers a comparatively low torque in its lower speed range, since the torque increase from a conventional turbocharger Depending on the system, the amount of air supplied into the intake tract of the engine depends on the exhaust gas flow of the internal combustion engine which drives the turbine of the turbocharger. This phenomenon known as turbo lag can be mitigated with regard to its characteristic of turbochargers with variable geometry, in which the turbine blades are designed to be adjustable in dependence on the available driving exhaust gas flow. Since turbochargers with variable geometry are comparatively expensive to manufacture and only controllable with complex control and regulation methods, there is a need in the motor vehicle industry to achieve a relatively high drive torque of the internal combustion engine with simpler devices and / or methods even at low engine speeds.

Against this background, DE 39 06 312 C1 and DE 199 44 946 A1 each disclose a method and a device for reducing the turbo lag, in which a diesel engine equipped with a turbocharger is accelerated from a compressed air Memory injected a certain amount of air into the intake manifold of the engine and the fuel injection quantity is adjusted accordingly. The compressed air required for the engine can be taken from a compressed air reservoir of a compressed air brake system of the vehicle.

From the above-mentioned publications WO 2006/089779 A1 and WO 2006/089780 A1, it is also known to use a separate device for Frischgas- or compressed air supply to reduce the mentioned turbo lag in a turbocharged internal combustion engine. This arrangement, which is arranged in the intake region of the internal combustion engine, has an air intake tract as intake manifold, which has an adjustable throttle valve and a first end connection for the intake air to flow in, and a second end connection for outflow toward the cylinders of the engine. The throttle valve is coupled for adjustment to a controllable by a control device adjustment. Between the throttle valve and the second end port, a compressed air port is formed with an opening which opens into the tubular interior of the device. It is further provided that the compressed air connection with a valve having a locked and arbitrarily open positions having compressed-quantity control device cooperates, which is controlled via an electrical input from an electrical control unit. The adjustment of the throttle valve is forcibly actuated by the flow control device and / or the control unit such that a fully locked position of the flow control device is assigned to a fully open position of the throttle.

To control this known from WO 2006/089779 A1 and WO 2006/089780 A1 devices for compressed air injection into the intake tract of the internal combustion engine, the control unit uses torque request signals from the accelerator pedal, a traction control, a speed control device and / or an electrical stabilization Program, or by means, which send an external torque request to the engine control system.

It is also known from WO 2006/089779 A1, that in the optimal control of the device for supplying the turbocharged internal combustion engine with compressed air - or as formulated with fresh gas - the control program of the control unit of this device knows predetermined information about the conditions, from when a Air injection should be performed or terminated. For example, it can be taken into account that professional long-distance drivers or bus drivers each have individual driving styles that require average acceleration values. Thus, such a driver may prefer certain shift points when shifting the transmission. These can be detected, stored and prepared by said controller. This data is used by the controller, for example, to determine the duration of the compressed air injection and for the operation of the throttle. This procedure is intended to prevent the consumption of compressed air being unnecessarily and unfavorably high. In particular, it is provided here that the duration of the compressed air injection and throttle valve operation is adaptively regulated by the frequency of the driver's request for an acceleration by the control software.

Furthermore, a generic device is known from WO 2006/037564 A1, in which the compressed air taken from a compressed air reservoir can also be fed directly in front of the inlet valve of a cylinder of the internal combustion engine.

Since the interaction of a generic device for supplying a turbocharged internal combustion engine with additional compressed air according to WO 2006/089779 A1 and WO 2006/089780 A1 with other facilities in the field of internal combustion engine and in the other vehicle powertrain is quite complex, it requires the optimal use of sol - chen device in a motor vehicle, whether commercial vehicle or passenger vehicle, special control method and control devices, which take into account the respective characteristics and requirements of these powertrain components. A reduction in fuel consumption and exhaust emissions of a vehicle equipped in this way is also of particular importance.

The invention is therefore based on the object to present a method and a device for coordinated control and / or rules of the blowing of additional compressed air in facilities in the field of the internal combustion engine, which have an influence on the fuel consumption and / or the exhaust emission of the internal combustion engine.

The solution to this problem arises for the method and the device from the respective independent claims, while advantageous developments and refinements of the invention, the associated subclaims can be removed.

The invention is based on the finding that it is necessary for optimum control and / or regulation of a known device for supplying a turbocharged internal combustion engine with additional compressed air, also those devices and / or units to be taken into account, the fuel consumption and the exhaust emission of Influence internal combustion engine. The present invention is therefore concerned with the optimal operation of cooperation devices in the field of the internal combustion engine, which affect the fuel consumption and the exhaust emission of the internal combustion engine, with a device for supplying a turbocharged internal combustion engine with additional compressed air.

The term "transmission" in this description means all types of transmissions, for example, manual transmissions, automatic gearboxes, powershift transmissions, dual-clutch transmissions, stepped automatic transmissions and continuously variable transmissions.

The term "device for blowing additional compressed air into an air intake tract of the internal combustion engine" means the devices described above, regardless of whether the compressed air or the fresh gas from a compressed air tank of a compressed air brake system or other vehicle device is removed, or if the compressed air needs The device mentioned comprises all components and units necessary for its operation.

In addition, the invention is suitable for all devices for supplying the turbocharged internal combustion engine with compressed air, regardless of whether the compressed air is injected far in front of the cylinders of the internal combustion engine in the intake, whether it is injected directly before the inlet valve of such a cylinder in the inlet region thereof, or whether this injection of compressed air takes place in the exhaust gas stream of the internal combustion engine.

The exhaust gas turbochargers used (in short: turbocharger) may be conventional exhaust gas turbochargers or adjustable exhaust gas turbochargers, the latter having adjustable guide vanes in their inlet region or having a bypass valve with which the flow properties of the turbocharger can be actively influenced.

The invention is initially based on a method for operating a vehicle drive train with an internal combustion engine, with a turbocharger associated with this internal combustion engine, and with a device for injecting additional compressed air into devices in the region of the internal combustion engine. To solve the task, the invention provides according to the method that then additional compressed air is injected into the facilities in the field of the internal combustion engine, if this results in dependence on the current operating situation of the vehicle to an advantageous operating behavior of the internal combustion engine and / or of vehicle equipment, which are arranged in the exhaust stream of the same.

Accordingly, there is the possibility of injecting additional compressed air at different points in the region of the internal combustion engine, that is, regardless of which amount of air the engine draws in the pure suction mode and / or gets supplied by the exhaust gas turbocharger. In order for the additional compressed air to be compressed actually leads to a reduction of the fuel consumption of the internal combustion engine and / or to reduce the exhaust emission of the same, this compressed air injection is in the range of devices, devices or components which are arranged in the region of the internal combustion engine and the combustion and / or or affect exhaust gas conversion process.

Thus, according to a first development of the invention, it is provided that the additional compressed air is injected directly in front of or into the exhaust-gas treatment device in such a way that the exhaust-gas cleaning behavior of the exhaust-gas treatment device is improved.

According to another embodiment of the invention can be provided that the additional compressed air is injected directly into the intake of the engine designed as a diesel engine and / or directly before or in the exhaust gas treatment device, such that reduces the flue gas emission of the internal combustion engine itself and / or the exhaust gas treatment device ,

If the exhaust gas treatment device is designed as a particle filter for filtering soot particles from the exhaust gas, according to another Embodiment of the invention, the compressed air blown directly before or in the exhaust gas treatment device, in such a way that in a regeneration phase of the same free burning of soot deposits by the relative to the exhaust gas increased oxygen antei I in the fresh or compressed air is favored.

To reduce the fuel consumption and thus indirectly also to reduce the exhaust emission can be further provided that at a startup of the engine to provide a high boost pressure injection of additional compressed air in the air intake tract of the engine then takes place when the engine just before their start running or driven by the starter at low speed rotates. By providing an initially very high boost pressure when starting the internal combustion engine, it can be assumed that with appropriate adaptation of the fuel injection, the fuel consumption of the internal combustion engine can be markedly reduced in this operating phase.

In this context, it can also be provided that during a starting operation of the internal combustion engine, an injection of additional compressed air into the air intake tract of the internal combustion engine with the throttle closed is so strong-ie with such high pressure-that the internal combustion engine reaches its own combustion-supported start-up in addition to the torque the starter of the blown and acting on the pistons of the internal combustion engine compressed air in the sense of an air motor is driven. In this procedure, the closed throttle valve is of particular importance in order to prevent air pressure from being lost from the exhaust gas turbocharger to the air intake tract via the duct.

The procedure just described obviously leads to a relief of the usually electric motor starter. It is therefore according to another embodiment of the invention provides that this discharge of the starter when starting the internal combustion engine by a comparatively strong injection of additional compressed air in the air intake tract of the internal combustion engine is preferably during a start-stop operation of the vehicle. Since the starting process is faster than usual feasible by the injection of compressed air into the air intake tract of the internal combustion engine to relieve the starter, this has a measurable reduction in fuel consumption and a noticeable reduction in exhaust emissions at the many starts at a start-stop operation of the vehicle Episode.

Furthermore, it can be provided that an injection of additional compressed air into the air intake tract of the internal combustion engine takes place when the driver of the vehicle signals the signal for a rapid change between a part-load operation and a full-load operation of the internal combustion engine through a correspondingly rapid or strong deflection of the accelerator pedal , Because of an additional compressed air injection faster reaction of the internal combustion engine with an increased engine torque can be assumed that immediately after the fast accelerator pedal deflection (for example, "kickdown") to the immediately supplied to the engine fuel right now the right amount of air available. As a result, a clean fuel combustion and at least a comparatively lower fuel consumption can be expected.

In addition, it can be provided according to the invention that the throttle valve in the air intake tract of the internal combustion engine is closed to carry out a pushing operation of the vehicle with shut off fuel supply to the engine and a blowing of additional compressed air is omitted. This makes it possible to increase the braking effect of the internal combustion engine in overrun operation of the vehicle. Another refinement of the method according to the invention provides that, in order to save fuel and to reduce the exhaust emission of the internal combustion engine when using an exhaust gas turbocharger with adjustable geometry, an injection of additional compressed air into the air intake tract of the internal combustion engine is coordinated with the adjustment of the exhaust gas turbocharger.

It is known that when adjusting the adjustable exhaust gas turbocharger whose vanes can be adjusted so that at low gas flow but high power consumption accelerates the exhaust gas through reduced flow cross sections in the turbocharger and then passed to the turbine blades of the same, which the speed of the turbine and thus the Performance of the turbocharger on the pump side increased. Conversely, at high gas flow and low power requirements by adjusting the vanes in the sense of large flow cross-sections in the turbocharger, the flow rate can be reduced, which reduces the pumping capacity of the same.

This aforementioned procedure can be further developed such that to achieve maximum torque of the internal combustion engine, the guide vanes are adjusted in the turbine inlet of the variable exhaust gas turbocharger before blowing additional compressed air into the air intake tract of the internal combustion engine in the direction of lowest possible flow resistance, which, as explained, the pump power of the exhaust gas turbocharger increased. In sum, with the effect of additionally injected compressed air results in the said maximum torque of the internal combustion engine.

Further, when using an exhaust gas turbocharger with adjustable geometry and a device for injecting additional compressed air into the intake tract of the internal combustion engine, it is possible to provide a pressure drop in the additional compressed air to be injected into the intake tract a predetermined pressure limit value is detected, and that the guide vanes of the exhaust gas turbocharger are adjusted so that at the end of blowing the additional compressed air supplied by the exhaust gas turbocharger boost pressure corresponds to the normal pressure of the exhaust gas turbocharger at the then current speed of the internal combustion engine.

Finally, when using a technically less demanding exhaust gas turbocharger with a bypass valve, a so-called "waste gate", and a device for blowing additional compressed air into the intake tract of the internal combustion engine for setting a maximum engine torque provided that the bypass valve at a blowing of additional compressed air in the air intake tract of the internal combustion engine is switched so that the flow resistance is minimized in the exhaust passage.

Finally, it can also be provided in this technically simpler exhaust gas turbocharger with bypass valve according to the invention that a pressure drop is detected in the additionally compressed air to be injected into the intake under a predetermined pressure limit, and that the bypass valve of the exhaust gas turbocharger is adjusted so that at the end the blowing of the additional compressed air supplied by the exhaust gas turbocharger boost pressure corresponds to the normal pressure of the exhaust gas turbocharger at the then current speed of the internal combustion engine.

The invention also relates to a device for operating a vehicle drive train with an internal combustion engine, to a turbocharger associated with this internal combustion engine and to a device for injecting additional compressed air into devices in the region of the internal combustion engine, in particular for carrying out the above-mentioned method. This device is characterized in that the device for injecting additional compressed air is designed and arranged in such a way that it uses compressed air in the air intake tract and directly before or into the exhaust gas treatment system. Anläge the internal combustion engine is inflatable that this Einblaseinrichtung is controllable with a switching and / or control valve in the region of the air intake and / or with a switching and / or control valve in the exhaust treatment plant, and that these switching and / or control valves of at least a control unit can be controlled, which is connected to sensors for detecting the operating situation of the internal combustion engine, the drive train and the vehicle.

The invention will be explained in detail below with reference to an embodiment. For this purpose, the description of a drawing figure is attached, in which a schematic representation of a vehicle drive train is shown with a device for blowing compressed air in facilities in the field of the internal combustion engine.

To the vehicle drive train 1 shown in the figure includes a equipped with a turbo compressor 17 diesel engine 2 with six arranged in a row in the cylinder block 6 cylinders 3. The suction lines 4 of the cylinder 3 are connected to a manifold 5, which has a connecting flange 7, what a Air intake tract 8 is connected to its second end port 9 for the outflow of air. The first end connection 10 for the inflow of air is coupled by a line 11 to the outflow opening 12 of an intercooler 13, whose inflow opening 14 is connected by a line 15 to the outflow opening 16 of the turbo-compressor 17. To the inflow opening 18 of the turbocompressor 17, an air filter 19 is connected to a line 20. The turbocompressor 17 forms part of the turbocharger 22 whose exhaust gas turbine 23 is connected with its inflow opening 24 to the outflow opening 25 of the exhaust pipe 26. The turbocompressor 17 and the exhaust gas turbine 23 are fixed to a rotatably mounted shaft 21. The cylinders 3 are connected by exhaust pipes 27 to the exhaust pipe 26 and the exhaust port 28 of the exhaust gas turbine 23 is fluidly connected to the exhaust pipe 29.

The fuel supply of the cylinder 3 via injectors 30, whose control is performed by the line 31 from the first output 32 of the electronic control unit (EDC) 38. To the input 37 of the electronic control unit 38, the output 34 of the electronic control unit 33 is connected by the line 36. This latter control unit 33 is provided with an actuating member which is formed in this embodiment as an accelerator pedal 35. The electrical connection 39 of the electronic control unit 38 is coupled by the collecting line 40 to the electrical connection 41 of the air intake tract 8. The dashed control line on the air intake tract 8 illustrates that the electronic control unit 38 controls a servomotor, not shown, for actuating the throttle flap 63. With this throttle valve 63, the amount of air sucked by the diesel engine 2 is adjustable.

The air intake tract 8 has a compressed air connection 42, which is connected by the line 43 to the outlet connection 44 of a compressed air tank 45. The feed port 46 of the compressed air tank 45 is connected by the line 47 to the compressed air port 48 of a pneumatic compressor 49. In line 47 and a pressure regulator 50 and an air dryer 51 are installed. The air compressor 49 has an intake 52, which is provided with an air filter 53. The shaft 54 of the air compressor 49 is connected by a belt drive 55 to the main shaft 56 of the turbocharged diesel engine 2. However, the invention also covers such compressed air compressors which are driven by an electric motor which can be controlled by, for example, the electronic control unit 38 (not shown).

Furthermore, the figure shows that the compressed-air compressor 49 is connected via a control unit 73 via an electronic control unit 38. controllable coupling 71 is connected to the belt drive 55 on the internal combustion engine 2, so that this air compressor 49 is only activated by the controller 38 when the pressure in the compressed air tank 45 must be filled. To determine the current pressure in the pressure vessel 45, a pressure sensor 79 is arranged there, the measuring signal of which can be conducted via a sensor line 80 to the control unit 38 and / or to the transmission control unit 66.

The activation of the air compressor 49 is for example very advantageous if the vehicle is in overrun on a downhill slope to increase the power of the air compressor 49, the braking effect of the drive train 1.

Moreover, the figure shows that the internal combustion engine 2 can be driven by a preferably electromotive starter 59 and thus can be started, which can engage with its pinion 58 in a ring gear 57 of the flywheel of the internal combustion engine 2. The flywheel is attached to the ring gear 57 in a known manner to the main shaft 56 of the engine 2. The starter 59 is connected via a control line 72 to the electronic control unit 38 of the injector for additional compressed air and therefore switched on and off by this controller 38.

In addition, an activatable by the electronic control unit 38 electromagnetic control and regulating valve 65 is arranged in the conduit 43, with the injection or injection of additional compressed air from the compressed air tank 45 in the air intake tract 8 is possible, if this to influence, in particular to increase the Torque of the diesel engine 2 makes sense. The control valve 65 is controlled by the electronic control unit 38 via the collecting line 40, which in the area of the air intake tract 8 in a control line (shown in small dashed lines) to the control tion of the servomotor of the throttle valve 63 and in a control line (shown in large dashed lines) branches to control the control valve 63.

Furthermore, the figure shows schematically that the internal combustion engine 2 is the drive side via the main shaft 56 rotatably connected to the input side of a starting and shifting clutch 60, while the output side of this starting and shifting clutch 60 is coupled to the transmission input shaft 61 of an automatic transmission 62. The starting and shifting clutch 60 is designed as an automatically operable clutch and therefore equipped with a clutch actuator 74, which is connected via a control line 75 to the transmission control unit 66 and is commanded by the latter.

If it requires the performance of the diesel engine internal combustion engine 2, on the input side before the start-up and clutch 60 also not shown here, a torsional vibration damper may be arranged, which, however, is known per se. The automatic transmission 62 has an output shaft 64 which is connected to the vehicle wheels 78 via drive shafts (not shown) and a differential gear.

In the present exemplary embodiment, the automatic transmission 62 is designed as an automated manual transmission whose known gear actuators 70 are connected to the transmission control unit 66 via control lines 69. With the help of these Gangaktuatoren 70 gears can be switched on and interpreted in a known manner or quite generally translation changes are performed. The transmission control unit 66 is also connected via sensor lines 68 with sensors 67 on the transmission 62, by means of which the transmission control unit 66 determines switching-relevant information. Such information is first of all the rotational speeds of the transmission input shaft 61 and the transmission output shaft 64 as well as position and / or position signals of the gear actuators 70. In addition, the transmission control unit 66 and / or the control unit 38 use a speed sensor 77 at the Transmission output shaft 64 or a vehicle wheel 78 determines the vehicle speed and with a speed sensor, not shown, on the main shaft 56 of the engine 2, the engine speed. Based on these as well as other information, the gear change operations in the automatic transmission 62 are prepared and performed.

The powertrain 1 works with regard to the basic functions of the device 8 for supplying the diesel engine 2 with additional compressed air initially as follows:

The cylinders 3 of the turbocharged diesel engine 2 are supplied with fresh gas through the suction lines 4, the manifold 5, the air intake tract 8, the line 1 1, the intercooler 13, the line 15, the turbo-compressor 17 and the air filter 19 when the engine speed is constant , The exhaust gases leave the cylinders 3 through the exhaust pipes 27, the exhaust pipe 26, the exhaust gas turbine 23, the exhaust pipe 29 and an exhaust treatment plant 100.

When the driver quickly depresses the accelerator pedal 35 to rapidly increase the engine torque or the engine speed, the diesel engine 2 needs more fuel and more fresh gas or air than before. The additional fuel is fed into the cylinders 3, but the increase in the amount of fresh gas supplied by the turbocharger 22 remains insufficient. In addition, at low engine speeds, the pressure of the fresh gas in the intake manifold 8 is low, which is constantly determined in the interior by a pressure sensor, not shown, and directed to the electronic control unit 38. In this operating state, the throttle valve 63 is fully open. The electronic control unit 38 then determines, with the aid of a control program, that the pressure in the interior of the air intake tract 8 does not increase sufficiently quickly and an additional air injection is to be carried out. The control program has predetermined information about the conditions when the additional air injection has to begin. At the beginning, the throttle valve 63 is moved in the direction of closing and the compressed air injection is released by opening the valve 65 from the compressed air tank 45 into the air intake tract 8. The duration of the air injection is also specified by the control program, which takes into account the pressure difference and the absolute pressure in the air intake tract 8.

The control program is initially intended to prevent the compressed air consumption from the compressed air tank 45 being so high that the brake safety of an air brake system connected to the compressed air tank 45 is adversely affected.

Further, it can be seen in the single figure that the transmission control unit 66 is connected via the data line 76 of the CAN bus system to the control unit 38 of the device for injecting additional compressed air, the latter may also be referred to as engine control unit. Between these two control units 38, 66 is constantly an exchange of information about whether and if so when and to what extent an injection of additional compressed air in the intake tract 8 of the engine 2 to increase the engine torque and support a gear shift can be done and / or done should.

Only through this exchange of information starting operations with the starting and shifting clutch 60 and the ratio change operations or gear shifts in the automatic transmission 62 can be carried out meaningfully in a vehicle in which such means for injecting additional compressed air into the air intake tract 8 of the internal combustion engine 2 is implemented. In addition, the exact coordination of the control of the blowing of additional compressed air into the intake tract 8 of the internal combustion engine 2 allows for the preparation and implementation of ratio change processes in the car matgetriebe 2 very advantageous modes of operation of the vehicle drive train 1, which was previously not possible and what has already been discussed earlier.

Against this background, the starting process of a vehicle equipped in this way is of particular importance, since it usually starts with engine speeds that are so low that an increase in the engine torque does not yet occur due to the effect of the exhaust gas turbocharger 22. This is especially unfavorable when, for example, a poorly motorized passenger vehicle or a heavily laden commercial vehicle to be approached on a slope. In addition, there are other, safety-related boundary conditions that require a coordinated interaction of the starting and shifting clutch 60 with the control unit 38 for controlling the blowing of compressed air into the intake tract 8 of the internal combustion engine 2.

Thus, it can be provided that only additional compressed air is blown into an air intake tract 8 of the internal combustion engine 2, if this results in an advantageous operating behavior of the vehicle depending on the current operating situation of the vehicle for driver safety, fuel consumption and / or ride comfort ,

In particular, it may be provided that the coordinated operation of the starting and shifting clutch 60 and the device for injecting additional compressed air into the air intake tract 8 of the internal combustion engine 2 takes place in such a way that the actuating speed of a clutch actuator 74 and the time, the pressure and the duration of the injection of additional compressed air is coordinated with each other.

It is also advantageous if the coordinated actuation of the starting and shifting clutch 60 and the device for injecting additional compressed air by adjusting the control valve 65 in dependence on the driving mass, the driving resistance, the road gradient, the upcoming route, the ambient temperature, expected by the driver or predetermined and stored in a control unit 38, 66 startup period, the driver's performance and / or the dynamic behavior of the device for injecting additional compressed air and the clutch actuator 74 is controlled.

In this case, the mentioned route information may originate from a satellite-based navigation system, while the values for the vehicle mass are from a vehicle mass sensor, the ambient temperature from a temperature sensor, the road inclination from a tilt sensor or the navigation system, the driver's power requirement from an angle sensor on the accelerator pedal 35 and the current driving resistance come from a rolling resistance determination program.

The said operating conditions are provided in the CAN bus system (line 76) to the two control units 38 for the compressed air injection and 66 for the transmission and clutch control, which can control the control valve 65 of the injector to its operation. As not shown separately, other control devices via the CAN bus with the two control units 38 and 66 for the compressed air injection and the automatic transmission 62 as well as the actuator 74 of the starting and shifting clutch 60, the air compressor 49 and a display and adjustment for the driver, which will be discussed below.

With regard to an optimal operation of the drive train 1, it is additionally provided that the device for injecting additional compressed air is intentionally not activated during a starting process when the engine torque requested by the driver is less than or equal to the engine torque in the initially pure suction operation of the internal combustion engine 2. Further, it is judged to be advantageous if it is provided that in a starting process, an injection of additional compressed air into the air intake tract 8 of the internal combustion engine 2 then takes place immediately, if it is clear from track information that the vehicle is to drive on a slope or such a slope imminent in the driving route.

Furthermore, an operating mode may be provided such that a compressed-air compressor 49 for generating the required compressed air is started immediately before starting, if it is clear from track information that the vehicle is to be approached on a slope or if such a gradient is imminent in the driving route, as well a compressed air tank 45 falls below a predetermined lower filling state.

In addition, an injection of additional compressed air into the air intake tract 8 of the internal combustion engine 2 can take place during a starting process such that the slip time of the starting and shifting clutch 60 and the starting rotational speed of the internal combustion engine 2 are reduced by an increased engine torque.

In addition, the drive train 1 and the control device can be operated so that an injection of additional compressed air in the air intake tract 8 of the internal combustion engine 2 takes place during a starting process such that when starting the internal combustion engine 2 by means of a starter 59 this by initially high gas pressures in the combustion chamber of the internal combustion engine 2 is relieved, which will be discussed again below.

It can further be provided that the injection of additional compressed air into the air intake tract 8 of the internal combustion engine 2 is provided by an anti-lock braking system, a traction control system, a roll stabilization program, an off-road program and / or a distance control system. is activated or deactivated depending on security-relevant decision criteria.

Finally, the injection of additional compressed air into the air intake tract 8 of the internal combustion engine 2 can be manually activated or deactivated by the driver by means of an input and display device, not shown, if he has justified cause.

To save fuel and to reduce the exhaust emission of the internal combustion engine 2, the invention now provides that then additional compressed air in devices 8 and / or 100 is blown in the area of the internal combustion engine 2, if this depending on the current operating situation of the vehicle to an advantageous Operating behavior of the internal combustion engine 2 and / or leads of vehicle equipment, which are arranged in the exhaust stream of the same.

As the exemplary embodiment according to the FIGURE shows, the abovementioned exhaust treatment system 100 is installed in the exhaust pipe 29 downstream of the exhaust gas turbocharger 22, through which the exhaust gas coming from the internal combustion engine 2 and the turbocharger 22 is conducted. The exhaust gas treatment plant 100 is controlled starting from the compressed air tank 45 via a compressed air line 101 drawn here interrupted, a control valve 102 and a short compressed air line 104 and / or regulated supplied with compressed air. The control valve 102 is connected via a control line 103 to the electronic control unit 38, which also controls the actuation of the control and regulating valve 65 to the intake manifold 8 of the internal combustion engine 2. As a result, a structure is provided by means of which controlled and regulated compressed air can be fed into the intake tract 8 of the internal combustion engine 2 as well as into or in front of the exhaust gas treatment plant 100 into the exhaust pipe 29. Because the controller 38 controls both valves 65 and 102, their operation can be coordinated, in such a way that their operation in dependence from the current operating situation of the vehicle to an advantageous operating behavior of the internal combustion engine 2 and / or the exhaust gas treatment plant 100 leads.

Thus, according to the embodiment shown in the single figure, it is provided that the additional compressed air is blown directly in front of or into the exhaust gas treatment device 100, such that the exhaust gas cleaning behavior of this exhaust gas treatment device 100 improves. If the exhaust gas treatment device 100 is a particle filter, then it is provided that the additional compressed air is blown directly into or into the exhaust gas treatment device 100, such that in a regeneration phase thereof the burn-off of soot deposits is favored.

Further, it is possible with the device shown in the figure that the additional compressed air is injected into the intake tract 8 of the engine designed as a diesel engine 2 and / or directly before or in the exhaust treatment device 100, such that the flue gas emission of the internal combustion engine 2 and / or the exhaust treatment device 100 is reduced.

In addition, it can be achieved by the illustrated device that when starting the internal combustion engine 2 to provide a high boost pressure blowing additional compressed air into the air intake tract 8 of the engine 2 then takes place when the internal combustion engine 2 just before their start is not running or from the Starter 59 driven at low crankshaft speed rotates.

In addition, this device makes it possible for a blowing-in of additional compressed air into the air intake tract 8 of the internal combustion engine 2 to be so strong when the throttle valve 63 is closed that the internal combustion engine 2, in addition to the torque of the starter 59, until its own combustion-supported startup driven by the injected compressed air, for example in the sense of a compressed air motor.

This relief of the starter 59 when starting the internal combustion engine 2 is preferably carried out by a relatively strong injection of additional compressed air into the air intake tract 8 of the internal combustion engine 2 during a start-stop operation of the vehicle.

In addition, with the illustrated device, a procedure is possible such that an injection of additional compressed air in the air intake tract 8 of the internal combustion engine 2 then takes place when the driver of the vehicle by a correspondingly rapid or strong deflection of the accelerator pedal 35, the desire for a quick change between a partial load operation and a full load operation of the internal combustion engine 2 is signaled.

According to another mode of operation of the device is provided that to perform a coasting operation of the vehicle with the fuel off the internal combustion engine 2, the throttle valve 63 is closed in the air intake tract 8 of the internal combustion engine 2 and a blowing of additional compressed air is omitted.

When using an exhaust gas turbocharger 22 with adjustable geometry, so with externally operated actuated guide surfaces at the compressor inlet, or with a bypass valve, an injection of additional compressed air in the air intake tract 8 of the engine 2 can be advantageously coordinated with the setting of the exhaust gas turbocharger 22. Thus, an operating mode may be provided according to which the guide vanes in the turbine inlet of the adjustable exhaust-gas turbocharger 22 are set before or during the injection of additional compressed air into the air intake for setting a maximum engine torque. tract 8 of the internal combustion engine 2 are adjusted in the direction of the lowest possible flow resistance.

Accordingly, to set a maximum engine torque when using a technically simpler turbocharger 22 with a bypass valve on the same, the bypass valve is switched before or upon injection of additional compressed air in the air intake tract 8 of the engine 2 so that the flow resistance in the exhaust passage is also minimized ,

Finally, with the device, the method according to the invention can be carried out in such a way that with the use of an adjustable geometry exhaust gas turbocharger 22 or with a bypass valve, a pressure drop in the additionally compressed air to be injected into the intake tract 8 is detected below a predetermined pressure limit, and that the guide vanes of the exhaust gas turbocharger 22 and the bypass valve are adjusted so that at the end of blowing the additional compressed air supplied by the exhaust gas turbocharger 22 boost pressure corresponds to the normal pressure of the exhaust gas turbocharger 22 at the then current speed of the internal combustion engine 2.

According to the invention, the device for carrying out the above-described method and its various variants is characterized in that the device for injecting additional compressed air is designed and arranged such that it with compressed air in the air intake tract 8 and immediately before or in the exhaust treatment plant 100th the internal combustion engine 2 is inflatable that this Einblaseinrichtung with a switching and / or control valve 65 in the region of the air intake tract 8 and with a switching and / or control valve 102 in the exhaust treatment plant 100 is controllable, and that these switching and / or control valves 65, 102 of at least one control unit 38, 66 are controllable, which with sensors 67, 74, 77, 79 are connected for detecting the operating situation of the internal combustion engine 2, the drive train 1 and the rest of the vehicle.

REFERENCE CHARACTERS

Vehicle powertrain

Internal combustion engine, diesel engine

cylinder

suction

manifold

cylinder block

flange

air intake

Second end connection, outflow area

First end connection, inflow area

management

outflow

Intercooler

inflow

management

outflow

Turbo compressor

inflow

air filter

management

wave

Turbocharger, turbocharger

exhaust turbine

inflow

outflow

exhaust collecting pipe

exhaust pipe

outflow exhaust pipe

injection

management

output

control unit

output

accelerator

management

entrance

Electronic control unit

connection

manifold

connection

Compressed air connection

management

outlet

Air receiver

feed connection

management

Compressed air connection

Air Compressor

pressure regulator

air dryer

suction

air filter

wave

belt drive

main shaft

sprocket

Pinion of the starter

Starter Start and shift clutch Transmission input shaft Transmission, automatic transmission Throttle valve Transmission output shaft Control valve Transmission control unit Sensor on gearbox Sensor cable Control line to boost actuator 70 Actuator on gearbox Actuator on clutch of compressed air compressor Control line to starter Control line to actuator 71 Clutch actuator Control line to clutch actuator Data line, CAN bus Speed sensor vehicle wheel Pressure sensor Sensor line Exhaust gas treatment system Compressed air line from compressed air tank 45 Control valve Control line to control unit 38 Compressed air line from control valve 102 to exhaust gas treatment system 100

Claims

Patent Attorney

1. A method for operating a vehicle drive train (1) with an internal combustion engine (2), with a said engine associated turbocharger (22) and with a device for blowing additional compressed air in facilities in the field of the internal combustion engine (2), characterized Porsche n zei ch n et that then additional compressed air in devices (8, 100) in the field of the internal combustion engine (2) is blown, if this results in dependence on the current operating situation of the vehicle to an advantageous operating behavior of the internal combustion engine (2) and / or of vehicle equipment, which are arranged in the exhaust stream of the same.

2. The method of claim 1, characterized Porsche Style n zei ch et that the additional compressed air is blown directly in front of or in the exhaust gas treatment device (100), such that the exhaust gas cleaning performance of this exhaust treatment device (100) improved.

3. The method of claim 1 or 2, characterized Porsche Style n zei chnet that the additional compressed air is blown directly before or in a designed as a particle filter exhaust treatment device (100), such that in a regeneration phase of the same the burning of soot deposits is favored.

4. Method according to one of the preceding claims, characterized in that the additional compressed air is injected into the intake tract (8) of the internal combustion engine (2) designed as a diesel engine and / or directly before or into the exhaust gas treatment device (100), such that the flue gas emission of the internal combustion engine (2) and / or the exhaust gas treatment device (100) is reduced.

5. The method of claim 1, characterized Porsche Style n zei ch et, that at a starting process of the internal combustion engine (2) for providing a high boost pressure, an injection of additional compressed air in the air intake tract (8) of the internal combustion engine (2) then takes place when the Internal combustion engine (2) just before their start is not running or driven by the starter (59) rotates at low speed.

6. The method according to claim 5, characterized Porsche Style n zei ch et et, that at a starting process of the internal combustion engine (2) an injection of additional compressed air in the air intake tract (8) of the internal combustion engine (2) with closed throttle (63) is so strong, in that the internal combustion engine (2) is driven by the injected compressed air in addition to the torque of the starter (59) until it starts to burn by itself.

7. The method of claim 6, characterized Porsche Style n zei ch et, that a discharge of the starter (59) during starting of the internal combustion engine (2) by a comparatively strong injection of additional compressed air in the air intake tract (8) of the internal combustion engine (2) during a start-stop operation of the vehicle takes place.

8. The method according to any one of the preceding claims, characterized Porsche Style n zei ch et, that an injection of additional compressed air in the air intake tract (8) of the internal combustion engine (2) then takes place, if by the driver of the vehicle by a correspondingly fast or strong deflection the accelerator pedal (35) the desire for a quick change between a partial load operation and a full load operation of the internal combustion engine (2) is signaled.

9. The method according to any one of the preceding claims, characterized ge - ken n zei ch et et, that to perform a coasting operation of the vehicle with shut off fuel supply to the internal combustion engine (2), the throttle valve (63) in the air intake tract (8) of the internal combustion engine (2) is closed and a blowing of additional compressed air is omitted.

10. The method according to any one of the preceding claims, characterized Porsche Style n zei ch et, that with the use of an exhaust gas turbocharger (22) with adjustable geometry or with a bypass valve blowing additional compressed air into the air intake tract (8) of the internal combustion engine (2) the setting of the exhaust gas turbocharger (22) is coordinated.

11. The method of claim 10, characterized Porsche Style n zei ch et et that for setting a maximum engine torque, the vanes in the turbine inlet of the adjustable exhaust gas turbocharger (22) before or at a blowing additional compressed air into the air intake tract (8) of the internal combustion engine (2). be adjusted in the direction of the lowest possible flow resistance.

12. The method of claim 10, characterized Porsche Style n zei ch et, that for setting a maximum engine torque when using an exhaust gas turbocharger (22) with a bypass valve (wastegate) on the same the bypass valve before or at a blowing additional compressed air into the air intake (8) of the internal combustion engine (2) is switched so that the flow resistance in the exhaust passage is minimized.

13. Method according to claim 10, characterized in that, when using an exhaust gas turbocharger (22) with adjustable geometry or a bypass valve, a pressure drop occurs in the additionally compressed air to be injected into the intake tract (8) under a predetermined pressure. Threshold is detected, and that the vanes of the exhaust gas turbocharger (22) and the bypass valve are set so that at the end of Blowing the additional compressed air supplied by the exhaust gas turbocharger (22) boost pressure to the normal pressure of the exhaust gas turbocharger (22) at the then current speed of the internal combustion engine (2).

14. Apparatus for operating a vehicle drive train (1) with an internal combustion engine (2), with a turbocharger (22) associated with this internal combustion engine and with a device for injecting additional compressed air into devices in the region of the internal combustion engine (2), characterized in that Device for injecting additional compressed air is designed and arranged such that with her compressed air in the air intake tract (8) and directly before or in the exhaust treatment plant (100) of the internal combustion engine (2) is inflatable, that this Einblaseinrichtung with a switching and / or control valve (65) in the region of the air intake tract (8) and / or with a switching and / or control valve (102) in the region of the exhaust gas treatment plant (100) is controllable, and that these switching and / or control valves (65, 102) be controlled by at least one control unit (38, 66), with the sensors (67, 74, 77, 79) for detecting the operating situation of the Bren nkraftmaschine (2), the drive train (1) and the vehicle is connected.