EP1540153A1

EP1540153A1 - Internal combustion engine comprising a gas conveying system and operating method therefor

Info

Publication number: EP1540153A1
Application number: EP03798145A
Authority: EP
Inventors: Normann Freisinger; Thorsten HERGEMÖLLER; Roland Kemmler; Hans-Georg Lehmann; Martin Matt
Original assignee: DaimlerChrysler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2002-09-18
Filing date: 2003-08-30
Publication date: 2005-06-15
Also published as: JP2006517012A; DE10243317A1; WO2004029425A1; US20060096279A1; DE10243317B4

Abstract

Disclosed is an internal combustion engine (1) comprising a gas conveying system that is provided with a turbine (7) which is driven by an air flow and a pump (8) which is driven by said turbine (7) and by means of which gas can be supplied to the exhaust system (3, 4, 5). Also disclosed is a method for operating said internal combustion engine (1), according to which the quantity of injected fuel is adjusted in accordance with the conveying performance of the pump (8) when starting the internal combustion engine (1). The invention applies to motor vehicles, particularly passenger cars comprising an internal combustion engine with fuel injection.

Description

DaimlerChrysler AG

Internal combustion engine with gas delivery system and operating method therefor

The invention relates to an internal combustion engine with a gas delivery system with the features of the preamble of claim 1 and an operating method therefor with the features of the preamble of claim 12.

An internal combustion engine with a gas delivery system is known from US Pat. No. 6,094,909. The gas delivery system includes a turbine drivable by an air stream and a pump driven by the turbine that can deliver gas into the exhaust system. This gas delivery system is used at the start of the internal combustion engine to supply secondary air to the exhaust system so that unburned fuel components can be oxidized. The released heat of combustion is used to heat up the exhaust gas purification system, which means it is quicker to operate. The turbine is driven by an air flow which is caused by a pressure drop present in the intake line above a throttle element. However, the supply of secondary air only takes place to a sufficient extent when the turbine or the pump driven by it has a sufficient speed, which takes some time, so that secondary gas cannot be provided immediately by the gas delivery system after the internal combustion engine has started. Except for the delivery of secondary air when starting the internal combustion engine, no further functions are provided for the gas delivery system. In contrast, the object of the invention is to specify an internal combustion engine with a gas delivery system and an operating method therefor with which low-emission internal combustion engine operation and good utilization of the gas delivery system are made possible.

This object is achieved according to the invention by an internal combustion engine with the features of claim 1 and by a method with the features of claim 12.

The internal combustion engine according to the invention is characterized in that, when the internal combustion engine is started, its fuel injection quantity can be set as a function of the delivery rate of the pump. Fuel injection preferably takes place only when a minimum delivery rate of the pump is reached, so that the start of fuel injection is dependent on the delivery rate of the pump. It is thereby achieved that sufficient secondary air can be added to the exhaust system at the start of fuel injection by means of the pump in order to be able to re-oxidize unburned fuel residues. When post-oxidations occur, incompletely burned fuel is oxidatively converted. The heat of reaction released quickly brings the exhaust gas purification system up to operating temperature, especially downstream of the secondary air addition point. Effective exhaust gas cleaning can thus be achieved quickly. In particular, harmful hydrocarbon emissions (HC emissions) can be reduced in the start-up phase. If, on the other hand, the start of fuel injection is not coordinated with the delivery rate of the pump and, for example, fuel is injected into the combustion chambers of the internal combustion engine before the pump has a minimum delivery rate, the unburned fuel in the exhaust system does not have sufficient air oxygen as a reaction partner for post-oxidation, so that more or less large amounts of HC are emitted. Becomes If, on the other hand, too little fuel is injected in relation to the delivery rate of the pump, the air / fuel ratio (λ) required for post-oxidation is too high, and post-oxidation cannot take place either. The consequence is that the catalytic converters start up late, so that pollutants are emitted over a relatively long time.

In an embodiment of the invention, the turbine can be driven by a partial flow of the combustion air sucked in by the internal combustion engine via the intake line, the partial flow being caused by a pressure gradient present above the throttle element. This measure makes it possible to dispense with additional units for driving the turbine of the gas delivery system.

In a further embodiment of the invention, the rotational speed of the internal combustion engine can be set before the start of fuel injection by controlling the internal combustion engine or by controlling an auxiliary unit assigned to the internal combustion engine. The speed of the internal combustion engine is preferably increased at the start of the starting process. This enables the internal combustion engine to quickly empty the intake manifold area and the intake manifold pressure to drop rapidly. The air mass drawn in per intake stroke thus decreases rapidly, so that an air / fuel ratio which is favorable for the operation of the internal combustion engine and for post-oxidation can be set at the start of the fuel injections. If the turbine of the gas delivery system is driven by the pressure gradient present above the throttle element in the intake manifold, the pump according to the invention also quickly achieves a sufficient delivery rate. As a result, a sufficient amount of secondary air can be conveyed into the exhaust system at a very early point in the starting phase, which in turn allows effective exhaust gas purification to take place quickly. In a further embodiment of the invention, the throttle element in the intake line can be set as a function of a pressure in the intake line. In particular, if the turbine of the gas delivery system is driven by the pressure gradient present above the throttle element in the intake manifold, depending on the amount of air sucked in by the internal combustion engine, the throttle element can be adjusted so that the turbine of the gas delivery system rapidly increases speed. The pump also quickly achieves a sufficient delivery rate.

In a further embodiment of the invention, the turbine can be driven by an air flow which is generated by a gas conveying unit which is arranged in the turbine inlet line or in the turbine outlet line or is connected to the turbine inlet line or to the turbine outlet line. With this measure, the run-up of the turbine and thus a sufficient delivery capacity of the pump can be achieved independently of the differential pressure present in the intake line via the throttle element.

In a further embodiment of the invention, the gas delivery unit is designed as an electrically driven gas delivery unit. The electrical drive of the gas delivery unit permits precise control of this unit and thus of the entire gas delivery system.

In a further embodiment of the invention, the gas delivery unit is designed as an evacuable gas container arranged in the turbine outlet line. When the evacuated gas container is opened, air is drawn into the container via the turbine and the turbine is driven with it. There is practically no auxiliary energy to be used. The measure according to the invention therefore enables one of the Differential pressure across the throttle element independent operation of the gas delivery system.

In a further embodiment of the invention, the gas flow conveyed by the pump can be set as a function of an air / fuel ratio in the exhaust system. The conveyed gas stream is preferably set so that advantageous conditions for the post-oxidation exist downstream of the secondary air addition point. The setting is preferably carried out in such a way that a λ value of approximately 1.2 is set.

In a further embodiment of the invention, the gas flow delivered by the pump can be fed to an exhaust manifold assigned to the exhaust system and / or directly to a catalytic converter assigned to the exhaust system. Secondary air can thus be made available to the exhaust gas purification system where there are favorable conditions with regard to the occurrence of post-oxidation. When starting the internal combustion engine, the secondary air is preferably supplied to the exhaust manifold. If the internal combustion engine is operated rich after the starting process, secondary air can be added to the input of a catalytic converter installed in the underbody position to oxidize the unburned exhaust gas components.

In a further embodiment of the invention, exhaust gas can be supplied to the pump via the pump inlet line, and the exhaust gas flow conveyed by the pump can be supplied to the intake line. Exhaust gas recirculation is thus implemented by the gas delivery system. In addition to the secondary air supply, which is mainly carried out in the starting phase, the gas delivery system therefore fulfills another task and is therefore better utilized.

In a further embodiment of the invention, a vacuum container connected via the pump inlet line can be evacuated from the pump. The vacuum generated by the pump in the vacuum tank can be used to drive servo units be used. The gas delivery system thus fulfills another task and is better used.

The method according to the invention is characterized in that the fuel injection quantity is set as a function of the delivery capacity of the pump when the internal combustion engine is started. Fuel injection is preferably started when the pump has reached a minimum delivery rate. This ensures that no unburned fuel components get into the exhaust system without at the same time providing atmospheric oxygen for their post-oxidation. By adapting the fuel injection quantity to the delivery capacity of the pump, the λ value in the exhaust manifold is optimal for post-oxidation.

In one embodiment of the method, the throttle element is kept largely closed during the starting process before the start of fuel injection and is only opened after a minimum delivery rate of the pump has been reached. This ensures that conditions in the exhaust system are achieved very quickly, which enable effective post-oxidation of unburned fuel components.

In a further embodiment of the method, the speed of the internal combustion engine is increased during the starting process before the start of fuel injection. By increasing the starting speed, the air present in the intake manifold can be drawn off quickly, so that favorable λ values are very quickly available both for the operation of the internal combustion engine and in the exhaust system. The starting speed can be increased by reducing the compression work of the internal combustion engine. The internal combustion engine is preferably throttled, ie the exhaust valves remain open for a certain period or fully during the compression cycle. It is also advantageous to switch off or disconnect from Auxiliary units which are driven by the internal combustion engine.

In a further embodiment of the method, the turbine is driven at least temporarily by an air flow which is conveyed by a gas delivery unit which is arranged in the turbine inlet line or the turbine outlet line or is connected to the turbine inlet line or the turbine outlet line. This allows the turbine to start up quickly in the start-up phase, regardless of the differential pressure across the throttle element in the intake line, and the pump can therefore deliver secondary air very quickly. The gas delivery unit is preferably formed by an electrically operated pump or by a pressure container or vacuum container.

In a further embodiment of the method, the air flow delivered by the pump is set as a function of an air / fuel ratio in the exhaust system. This ensures that favorable conditions are created for the desired post-reactions and post-reactions can thus proceed in the desired manner. A λ value of 1.2 is preferably set in the exhaust manifold.

In a further embodiment of the method, depending on the operating state of the internal combustion engine, one of at least two addition points is selected at which the air flow conveyed by the pump is added to the exhaust gas. Due to the fact that secondary air can be supplied to the exhaust system at at least two points, it is possible to react flexibly to the conditions in the exhaust system, which primarily depend on the operating state of the internal combustion engine.

In a further embodiment of the method, a definable part of the exhaust system is cooled with the air flow conveyed by the pump if a predefinable threshold value for a temperature in the exhaust system is exceeded. With this embodiment of the invention, the gas delivery system additionally fulfills a cooling function, as a result of which it is better utilized, the exhaust system can be operated more reliably, and other cooling measures can be dispensed with.

In a further embodiment of the method, exhaust gas is at least temporarily removed from the exhaust system by the pump and fed to the intake line. The exhaust gas flow supplied to the intake line is preferably set as a function of the operating state of the internal combustion engine. The gas delivery system thus fulfills an exhaust gas recirculation function, so that the exhaust gas recirculation can be designed independently of the pressure conditions in the exhaust system and in the intake system of the internal combustion engine. The exhaust gas recirculation quantity can be adjusted as required by the dependency on the operating state.

In a further embodiment of the method, a vacuum container assigned to the internal combustion engine is evacuated from the pump via the pump inlet line to operate a vacuum-operated servo system. Through this further function of the gas delivery system, additional benefits can be drawn from this system and component simplification can be achieved.

The invention is explained in more detail below with the aid of drawings and associated examples. Show:

1 is a schematic block diagram of an embodiment of the internal combustion engine according to the invention with a gas delivery system,

2 shows a schematic block diagram of a further embodiment of the internal combustion engine according to the invention with a gas delivery system, 3 shows a schematic block diagram of a further embodiment of the internal combustion engine according to the invention with a gas delivery system,

4 shows a schematic block diagram of a further embodiment of the internal combustion engine according to the invention with a gas delivery system,

5 shows a schematic block diagram of a further embodiment of the internal combustion engine according to the invention with a gas delivery system.

1 shows an internal combustion engine 1, exemplarily designed as a four-cylinder, reciprocating piston engine with spark ignition, hereinafter referred to simply as an engine, with an associated gas delivery system, intake system and exhaust system. During operation, the engine 1 draws in air via the intake line 2 with a throttle element 6 arranged therein and releases exhaust gas to the environment via the exhaust manifold 3 and the connected exhaust line 4. A catalytic converter 5, hereinafter abbreviated as a catalytic converter, for exhaust gas purification is arranged in the exhaust line 4. The catalytic converter is designed here as a starting catalytic converter arranged close to the engine. A gas delivery system is assigned to the engine 1, which comprises a turbine 7 and a pump 8. The pump 8 can be driven by the turbine 7 via a drive shaft. A turbine inlet line 9 is connected to the turbine 7 on the inlet side and a turbine outlet line 10 is connected on the outlet side. The respective other end of the lines 9, 10 is connected upstream or downstream of the throttle element 6 to the intake line 2, so that the turbine 7 is connected in parallel to the throttle element. The air flow conveyed by the turbine 7 can be regulated by a controllable valve 20 in the turbine outlet line 10. A pump inlet line 11, which is connected here to the environment, is connected to the pump on the input side. On the outlet side there is a places 13, 14 in the exhaust manifold 3, or in the exhaust line 4 branching pump outlet line 12 connected to the pump.

The engine 1 is also assigned an unspecified injection system for injecting fuel, either directly into the combustion chambers of the engine 1 or into the intake area of the individual cylinders. Furthermore, the engine 1 has an engine control unit (not shown) for controlling or regulating the operation of the engine 1 and the systems associated with the engine 1. For this purpose, various sensors and measuring sensors, not shown, such as pressure sensors, an air mass meter in the intake line 2 and exhaust gas and temperature sensors in the exhaust line 4 are arranged in the intake system and in the exhaust system. The signals from the sensors are recorded and evaluated by the engine control unit. A starter (not shown) is also assigned to engine 1, the operation of which initiates the starting process and maintains it until autonomous engine operation.

The mode of operation of the system shown in FIG. 1 is explained below.

In a first area of application, the gas delivery system is used to achieve a low-emission start or warm-up of the engine 1. It is essential for this that the catalytic converter 5 arranged in the exhaust gas line 4 reaches sufficient effectiveness as quickly as possible, ie its so-called light-off temperature. For this purpose, the engine is operated with a rich air / fuel ratio from a specific point in time of the starting process and the reducing constituents in the rich exhaust gas thus obtained are burned upstream of the catalytic converter 5 by post-oxidation. In the following, the air / fuel ratio of the mixture supplied to engine 1 is referred to as engine λ or λ _M. The combustion heat released during the post-oxidation heats the catalytic converter 5, so that it quickly performs its cleaning function can meet. By supplying secondary air, the exhaust gas receives the oxygen content necessary for the post-oxidation to take place. The supply of secondary air takes place via the pump 8 driven by the turbine 7. By actuating a switching unit (not shown) in the pump outlet line 12, the addition point 13 in the exhaust gas collector 3 is released for the secondary air additions and the addition point 14 is shut off. The pressure gradient present above the throttle element 6, which is caused by the flow of the air drawn in by the engine 1, is used to drive the turbine. This pressure drop acts via the turbine inlet line 9 and the turbine outlet line 10 and therefore causes an air flow through the turbine 7 and thus a drive of the turbine 7 and the coupled pump 8.

The prerequisite for the post-oxidation to occur is the presence of a flammable mixture. For a low-emission engine start, it is therefore important to coordinate the fuel injection quantity and secondary air delivery. The aim is to start the post-oxidations as early as possible when starting the engine 1.

According to the invention, the fuel injection quantity is set as a function of the delivery capacity of the pump 8 during the starting process. Preferably, no fuel is initially injected at the start of the starting process, since at this point in time the pump 8 is still not delivering any secondary air. The reason for this is that the pressure drop across the throttle element 6 is initially still missing or too low. Since the speed of the engine 1 is typically comparatively low during the starting process, typically around 200 rpm, the build-up of a pressure drop over the throttle element takes place comparatively slowly. In order to accelerate the pressure build-up, the throttle element is set as a function of the negative pressure present in the intake line 2 downstream of the throttle element 6. Preferably at Starting process in the absence of negative pressure, the throttle element is completely closed. This is the case immediately at the start of the start process. It is thereby achieved that the air in the line volume between the throttle element 6 and the air inlet of the engine cylinder is quickly drawn off the engine. Thus, a differential pressure builds up quickly above the throttle element 6, the turbine 7 picks up speed correspondingly quickly, and the pump 8 conveys secondary air correspondingly quickly.

The fuel injection is preferably only started when the pump 8 has reached a minimum delivery rate, which can be determined, for example, with the aid of a speed sensor on the pump 8. The time period from the start of the starter actuation to the start of fuel injection can advantageously also be set in a time-controlled manner. Here, for example, a table stored in the engine control unit can be used, in which the time periods until the start of the fuel injection are stored. The coolant temperature of the engine 1 or the ambient temperature can also be taken into account.

The amount of fuel injected per unit of time is preferably set so that an engine λ of approximately λ _M = 0.8 results. An ignitable mixture is thus present in the combustion chambers of engine 1 and engine 1 can continue to run without starter support. With the start of this self-sufficient engine running, the engine speed, the amount of air sucked in and the pressure drop across the throttle element 6 increase. According to the vacuum-dependent setting, the throttle element 6 is opened when a predeterminable vacuum value is reached. The amount of secondary air conveyed by the pump 8 into the exhaust manifold 3 is controlled using the Adjustment valve 20 in the turbine outlet line 10 limited so that favorable conditions result in the exhaust manifold 3 for the course of post-oxidations. The amount of secondary air is preferably set such that an air / fuel ratio, hereinafter referred to as exhaust gas λ or λ _A , of approximately λ _A = 1.2 is set for the exhaust gas.

The time period until a sufficient amount of secondary air is delivered can be shortened even further if the starting speed of the engine 1 is increased during the starting process. This is achieved according to the invention by reducing the compression work of the engine 1. With a variable compression ratio, this is reduced in the starting phase of the starting process. It is also advantageous to dethrottle the engine 1 by opening the exhaust valves in the compression cycle. It is also advantageous to temporarily disconnect auxiliary units that are driven by engine 1. For example, a generator or a coolant pump can be disconnected. This reduces the mechanical power loss of the engine 1 and the speed during the starting process is increased.

After a stable and self-sufficient engine running and the starting temperature of the starting catalytic converter 5 have been reached, the starting process can be regarded as ended and the secondary air addition into the exhaust gas collector 3 is ended. The secondary air additions can be terminated by closing the adjusting valve 20 or closing a switching means (not shown) in the pump outlet line 12.

In a further area of application, the gas delivery system is used to reduce emissions when the engine 1 is operating richly outside the starting process, for example when accelerating. g or at full load. Under these conditions, there is a sufficient pressure drop across the throttle element to operate the turbine 7. In this application of the gas delivery system, secondary air is fed into the exhaust gas from the pump 8 at the addition point 14 of a catalyst 5, which in this case is preferably arranged remote from the engine. An exhaust gas λ of about λ _A = 1.0 is set. Under these conditions, reducing exhaust gas constituents are oxidized by the catalytic converter 5 and pollutant reduction is achieved even during acceleration or full load operation.

In another area of application, the gas delivery system is used to cool part of the exhaust system. For example, comparatively cool ambient air can be blown into the air gap of an air-gap-insulated exhaust manifold or catalytic converter housing by the pump 8. This function of the gas delivery system is preferably activated when a decisive temperature in the exhaust system is exceeded. Overheating or damage to the exhaust system is thus avoided and the function of cleaning-effective components is maintained.

Fig. 2 shows schematically the arrangement of the engine 1 and the gas delivery system in a further preferred embodiment. The designation of components with the same effect corresponds to that in FIG. 1. In addition to the embodiment shown in FIG. 1, a further gas delivery unit is assigned to the gas delivery system here. This is designed as an electrically driven air pump 15, which is connected to a branch of the turbine inlet line 9. In addition, a shutoff valve 21 is provided in the turbine inlet line 9, with which the connection to Intake line 2 can be shut off upstream of the throttle element 6. With the help of the air pump 15, the turbine 7 can be started more quickly when the engine 1 is started. For this purpose, the shutoff valve 21 is closed at the start of the starting process, the valve 20 is opened and the air pump is switched on. Thus, air is conveyed via the turbine 7 practically immediately at the start of the starting process. Consequently, regardless of the build-up of differential pressure above the throttle element 6, a sufficient amount of secondary air for post-oxidations can be supplied to the exhaust manifold 3 after a short time, and the fuel injection is carried out as in the embodiment in FIG. 1. If a sufficient differential pressure is built up above the throttle element 6, the air pump is switched off and the shut-off valve 21 is opened. The turbine 7 is then driven by the air flow flowing through the lines 9, 10, which is caused by the differential pressure across the throttle element 6. All other functions of the gas delivery system are present analogously to the embodiment in FIG. 1.

3 schematically shows the arrangement of the engine 1 and the gas delivery system in a further preferred embodiment. The designation of components with the same effect corresponds to that in FIG. 1. In addition to the embodiment shown in FIG. 1, a further gas delivery unit is assigned to the gas delivery system , This is designed as an evacuable gas container 16, which is arranged in a secondary branch of the turbine outlet line 10. The gas container can be shut off on the inlet or outlet side with a shut-off valve 22 or 23. With the help of the evacuated gas container 16, the turbine 7 can be started more quickly during the starting process of the engine 1. For this purpose, the shutoff valve 22 is opened on the inlet side of the evacuated gas container 16 at the start of the starting process. The valves 20 and 23 remain closed. Thus, air is conveyed into the evacuated gas container 16 via the turbine 7 practically immediately at the start of the starting process. Consequently, regardless of the differential pressure build-up above the throttle element 6, a sufficient amount of secondary air for post-oxidation can be supplied to the exhaust manifold 3, and the fuel injection is carried out as in the embodiment in FIG. 1. If a sufficient differential pressure is built up above the throttle element 6, the valve 20 is opened and the valve 22 is closed. The turbine 7 is then driven with the air flow through the turbine inlet line 9 and the branch of the turbine outlet line 10 provided with the valve 20. The air flow is now caused by the differential pressure across the throttle element 6. So that a rapid turbine run-up can take place regardless of the differential pressure build-up above the throttle element 6, the gas container 16 must of course have a sufficient size. All other functions of the gas delivery system are present analogously to the embodiment in FIG. 1. For a new evacuation of the gas container 16, the valve 23 is opened and the valve 22 closed during normal engine operation. In particular, at an engine operating point with a large negative pressure downstream of the throttle element 6, such as, for example, during a push operation at high speed, the gas container 16 can be sufficiently evacuated for a new starting process.

FIG. 4 schematically shows the arrangement of the engine 1 and the gas delivery system in a further preferred embodiment. The designation of components having the same effect corresponds to that in FIG. 1. With the embodiment shown in FIG. 4, in addition to the functions of FIG. 1 shown embodiment, an exhaust gas recirculation can be realized. For this purpose, the gas delivery system has a branch of the pump inlet line 11 which is provided with a valve 24 and which is connected to the exhaust line 4 stands . The part of the pump inlet line 11 which is connected to the environment can also be shut off by the valve 25 arranged therein. Furthermore, a branch of the pump outlet line 12 leading downstream of the throttle element 6 into the intake line 2 is provided. This branch can also be shut off by the adjustable valve 26. If the gas delivery system is not required for secondary air delivery, exhaust gas can be delivered by the pump 8 at the addition point 18 into the intake line 2 during normal engine operation. For this purpose, the valve 24 is opened and the valve 25 is closed. The valve 26 is opened in accordance with the exhaust gas recirculation rate to be implemented. As described above, the pump 8 is driven by the air flow via the turbine 7 caused by the differential pressure across the throttle element 6. Compared to conventional exhaust gas recirculation systems with passive exhaust gas recirculation, in which the amount of exhaust gas recirculated is determined by the differential pressure between the exhaust pipe and the intake pipe, a higher exhaust gas recirculation rate can be achieved with the embodiment of FIG. 4. The reason for this is the active exhaust gas delivery realized by the pump 8. All other functions of the gas delivery system are present analogously to the embodiment in FIG. 1.

FIG. 5 schematically shows the arrangement of the engine 1 and the gas delivery system in a further preferred embodiment. The designation of components with the same effect corresponds to that in FIG. 1. In comparison to the embodiment shown in FIG. 1, the pump inlet line 11 is here at one evacuable gas container 17 connected. A connection to the environment that can be shut off via a valve 27 continues to exist. If the gas delivery system is not required for secondary air delivery, the pump 8 can evacuate the gas tank during normal engine operation. For this, the valve 27 is closed. The air drawn off from the gas container 17 can be supplied to the exhaust gas via the pump outlet line 12 or via a branch, not shown, are released to the environment. With the negative pressure generated in the gas container 17, vacuum-operated servo systems which are not specified here and which are connected to the gas container 17 can be operated. All other functions of the gas delivery system are present analogously to the embodiment in FIG. 1.

With the embodiments of the internal combustion engine and gas delivery system according to the invention, low-emission operation of the internal combustion engine can be implemented, as shown. The functions of the gas delivery system, which are available in addition to the secondary air delivery, make better use of this, and components can be saved. It goes without saying that within the scope of the invention, additional lines or valves in the gas delivery system make modifications of the illustrated embodiments possible.

Claims

DaimlerChrysler AG patent claims

1. Internal combustion engine with fuel injection, with a

Intake line (2) in which a throttle element (6) is arranged, an exhaust system (3, 4, 5) and a gas delivery system

- A turbine (7) which can be driven by an air flow, to which a turbine inlet line (9) and a turbine outlet line (10) are connected and

- A pump (8) which can be driven by the turbine (7) and has a pump inlet line (11) and a pump outlet line (12), via which the exhaust system (3, 4, 5) from the pump (8) can be supplied with gas, characterized that when the internal combustion engine (1) starts, its fuel injection quantity can be set as a function of the delivery capacity of the pump (8).

2. Internal combustion engine according to claim 1, characterized in that the turbine (7) can be driven by a partial flow of the combustion air sucked in by the internal combustion engine (1) via the intake line (2), the partial flow being provided by an over the throttle element (6) Pressure drop is caused.

3. Internal combustion engine according to claim 1 or 2, characterized in that the speed of the internal combustion engine during the starting process (1) before the start of fuel injection by controlling the internal combustion engine (1) or by controlling an auxiliary unit assigned to the internal combustion engine (1).

4. Internal combustion engine according to one of claims 1 to 3, d a d u r c h g e k e n n z e i c h n e t that the throttle element (6) is adjustable as a function of a pressure in the intake line (2) during the starting process.

5. Internal combustion engine according to one of the preceding claims, characterized in that the turbine (7) can be driven by an air flow which is generated by a gas delivery unit (15; 16) which is arranged in the turbine inlet line (9) or in the turbine outlet line (10) or is connected to the turbine inlet line (9) or to the turbine outlet line (10).

6. Internal combustion engine according to claim 5, d a d u r c h g e k e n e z e i c h n e t that the gas delivery unit is designed as an electrically driven gas delivery unit (15).

7. Internal combustion engine according to claim 5, so that the gas delivery unit is designed as an evacuable gas container (16) arranged in the turbine outlet line (10).

8. Internal combustion engine according to one of the preceding claims, characterized in that the gas flow conveyed by the pump (8) is adjustable as a function of an air / fuel ratio in the exhaust system (3, 4, 5).

9. Internal combustion engine according to one of the preceding claims, characterized in that the gas flow conveyed by the pump (8) one of the exhaust system (3, 4, 5) associated exhaust manifold (3) and / or directly one of the exhaust system (3, 4, 5) assigned catalytic converter (5) can be fed.

10. Internal combustion engine according to claim 1, so that exhaust gas can be fed to the pump (8) via the pump inlet line (11), and the exhaust gas flow conveyed by the pump (8) can be fed to the intake line (2).

11. Internal combustion engine according to claim 1, so that a vacuum container (17) connected via the pump inlet line (11) can be evacuated from the pump (8).

12. Method for operating an internal combustion engine with fuel injection and with

- An intake line (2) in which a throttle element (6) is arranged,

- An exhaust system (3, 4, 5) and

- A gas delivery system which comprises a turbine (7) which can be driven by an air flow and a pump (8) which can be driven by the turbine (7), in which the at least during a starting process

Exhaust system (3, 4, 5) supplied by the pump (8) is supplied gas, so that during the starting process of the internal combustion engine (1) the

Fuel injection quantity depending on the

Delivery rate of the pump (8) is set.

13. The method of claim 12, d a d u r c h g e k e n e z e i c h n e t, the throttle element (6) is kept mostly closed during the starting process before the start of fuel injection and is only opened after reaching a minimum delivery rate of the pump.

14. The method according to claim 12 or 13, so that the speed of the internal combustion engine (1) is increased during the starting process before the start of fuel injection.

15. The method according to any one of claims 12 to 14, characterized in that the turbine (7) is at least temporarily driven by an air flow which from a gas delivery unit (15; 16) in the turbine inlet line (9) or the turbine outlet line (10) arranged or connected to the turbine inlet line (9) or the turbine outlet line (10) is promoted.

16. The method according to any one of claims 12 to 15, so that the air flow conveyed by the pump (8) is adjusted as a function of an air / fuel ratio in the exhaust system (3, 4, 5).

17. The method according to any one of claims 12 to 16, characterized in that one of at least two addition points (13, 14) in the exhaust system (3, 4, 5) is selected depending on the operating state of the internal combustion engine (1) at which the air flow conveyed by the pump (8) is added to the exhaust gas.

18. The method according to claim 12, characterized in that a definable part of the exhaust system (3, 4, 5) is cooled with the air flow conveyed by the pump (8) when a predeterminable threshold value for a temperature in the exhaust system (3, 4, 5 ) is exceeded.

19. The method as claimed in claim 12, so that exhaust gas is at least temporarily removed from the exhaust system (3, 4, 5) by the pump (8) and supplied to the intake line (2) by the pump (8).

20. The method according to claim 12, so that a vacuum container (17) assigned to the internal combustion engine (1) for operating a vacuum-operated servo system is evacuated by the pump (8) via the pump inlet line (11).