CN112313399A

CN112313399A - Drive train for a motor vehicle and motor vehicle

Info

Publication number: CN112313399A
Application number: CN201980040705.7A
Authority: CN
Inventors: C·格森哈特
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2018-06-18
Filing date: 2019-06-17
Publication date: 2021-02-02
Anticipated expiration: 2039-06-17
Also published as: CN112313399B; WO2019243261A1; DE102018114553B4; DE102018114553A1

Abstract

A drive train for a motor vehicle and a motor vehicle. The invention relates to a drive train (1) for a motor vehicle (2), comprising: an internal combustion engine (3) having a plurality of cylinders (4), a piston which is guided linearly in the cylinders (4), and an exhaust manifold (5) for collecting exhaust gases which emerge from the cylinders (4); and a burner arrangement (6) for burning fuel outside the cylinder (4) for generating heat. The burner device (6) is connected in fluid communication with the exhaust manifold (5) in such a way that exhaust gas can be conducted from the burner device (6) into the exhaust gas channel (7) of the exhaust manifold (5). The invention further relates to a motor vehicle (2) having a drive train (1) having an internal combustion engine (3).

Description

Drive train for a motor vehicle and motor vehicle

Technical Field

The invention relates to a drivetrain for a motor vehicle having an internal combustion engine. The invention also relates to a motor vehicle having a drive train of this type.

Background

Internal combustion engines are designed for the combustion of liquid or gaseous fuels or fuel mixtures, in particular consisting of fuel and filtered and compressed air, in order to produce work for the expansion by means of reactants (sometimes referred to as reaction partners) associated therewith. Combustion can be initiated, for example, in an auto-ignition manner, for example in a diesel engine, by compressing a fuel mixture, or in an externally ignited manner, for example by means of an ignition spark additionally generated for this purpose.

When a plurality of fuels or fuel mixtures are combusted, exhaust gases such as, for example, carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons and soot particles occur as byproducts. In order to comply with increasingly stringent environmental regulations (umweltaflagen), modern motor vehicles have exhaust gas purification systems for purifying the exhaust gas and soot particles, such as, for example, catalysts, particle filters, etc.

In order to ensure a predefined exhaust gas purification result, known exhaust gas purification systems require certain operating conditions, such as, for example, an operating temperature, a regeneration temperature during a regeneration phase of the exhaust gas purification device, etc. When the catalytic converter has its operating temperature, the efficiency of the catalytic converter is significantly lower, for example, during a cold start of the motor vehicle than during longer driving operation. Also, the particle filter must generally be regenerated by means of heat in order to remove soot particles which accumulate there.

In order to improve the performance of exhaust gas purification devices, in particular during cold starts of internal combustion engines, various proposals have therefore been made. Fresh air can be introduced into the exhaust tract of the drive train by means of the secondary air system and the combustion of the remaining fuel present in the exhaust gases can be brought about via a corresponding control of the exhaust valves of the cylinders of the internal combustion engine. The combustion takes place, for example, directly in the exhaust manifold (abgasklummer), so that in this way a more rapid heating of the cooling liquid of the drive train can be brought about. Such systems are known for example from EP 3056705B 1 and CN 2006233803 a 1. Alternatively, DE 102016012457 a1 discloses a drive train for a motor vehicle, which has an additional heater for burning fuel and for heating an exhaust gas purification device. The additional heater is configured separately from the internal combustion engine and is configured for introducing exhaust gas into the exhaust system upstream of the exhaust gas purification system. In this way, the exhaust gas of the internal combustion engine and of the additional heater can be purified by means of the exhaust gas purification system.

The known drive train with a device for heating the exhaust gas purification system has the disadvantage that an inadequate purification of the exhaust gas is provided, in particular at cold start of the internal combustion engine. Furthermore, the integration of a secondary air system into the exhaust system is particularly difficult and is accompanied in part by adverse effects on the operation of the internal combustion engine, in particular due to crosstalk of the exhaust gas duct and deteriorated dynamics. Blowing air near the exhaust valve and enriching the combustion chamber charge with the mixture is done in many secondary air systems. Since the fresh air injected must react with the unburned fuel in the exhaust gas of the internal combustion engine, the functionality of this solution is very sensitive with regard to the implementation of the injection openings and the associated design of the internal combustion engine. The temporal distribution of the air quantity flowing into the exhaust duct is strongly dependent on the existing pressure ratio in the secondary air duct and the exhaust duct. The formation of an over-stoichiometric and sub-stoichiometric mixture quantity in the exhaust gas takes place alternately due to this principle. Furthermore, it is expected that conventional drive trains no longer meet further stringent environmental regulations, such as a reduction in the permitted amount of exhaust gas.

Disclosure of Invention

The object of the present invention is therefore to eliminate or at least partially eliminate the above-described disadvantages for a drive train for a motor vehicle and for a motor vehicle. The object of the present invention is, in particular, to create a drive train for a motor vehicle and a motor vehicle having such a drive train, which in a simple and cost-effective manner improves the heating of the exhaust gas purification system, in particular during a cold start of the internal combustion engine, and thus contributes to a reduction in the exhaust gas quantity of the drive train.

The above object is achieved by the patent claims. This object is achieved by a drive train for a motor vehicle having the features of independent claim 1 and by a motor vehicle having the features of independent claim 10. Further features and details of the invention emerge from the dependent claims, the description and the drawings. The features and details described in connection with the drive train according to the invention for a motor vehicle are also applicable here in the context of the motor vehicle according to the invention, and vice versa, respectively, so that the disclosure with respect to the various aspects of the invention is always mutually referenced or can be mutually referenced.

According to a first aspect of the invention, this object is achieved by a drive train for a motor vehicle. The transmission system has: an internal combustion engine having a plurality of cylinders, a piston guided linearly in the cylinders, and an exhaust manifold for collecting exhaust gases discharged from the cylinders; and a burner arrangement for combusting fuel outside the cylinder for generating heat. According to the invention, the burner device is coupled in fluid communication with the exhaust manifold in such a way that the exhaust gas can be conducted from the burner device into the exhaust gas channel of the exhaust manifold.

The internal combustion engine of the drive train has, in particular, an engine block in which a cylinder block is formed. Preferably, the engine block has a cooling channel for cooling. The exhaust manifold is preferably formed in a cylinder head of the internal combustion engine. The cylinder head and/or the exhaust manifold preferably have cooling channels for cooling. The cooling passages of the engine block are preferably configured to be in fluid communication with the cooling passages of the exhaust manifold or the cylinder head. In the cylinder head, an exhaust valve is preferably arranged for discharging exhaust gases from the cylinder block into an exhaust manifold. Furthermore, an intake valve for introducing a fuel-air mixture into the cylinder is preferably arranged in the cylinder head.

The burner apparatus is configured for combusting a fuel. The burner device is preferably configured for burning the same fuel as for the operation of the internal combustion engine. According to the invention, it is also possible to configure the burner device for burning an alternative fuel, such as, for example, methane. Furthermore, it is possible according to the invention, for example, to provide that the burner device for burning the fuel is formed directly in the exhaust gas duct of the exhaust manifold. It may furthermore be provided according to the invention that the drive train has a plurality of burner devices which are associated with the exhaust gas channels of different cylinders. In this case, a burner device is preferably associated with each exhaust gas channel of the cylinder in order to distribute the heat uniformly. Alternatively, the burner device may be configured according to the invention for distributing the exhaust gas of the burner device evenly over the exhaust gas channel of the exhaust manifold. The burner device is preferably arranged at the exhaust manifold in such a way that the exhaust gas of the burner device can be introduced into the exhaust manifold upstream of the convergence of the exhaust gas of the individual cylinders passing through the exhaust manifold.

Preferably, the drive train has a plurality of temperature sensors, which are preferably arranged at the exhaust manifold, in particular in association with the respective cylinder block. In this way, a temperature drop in the exhaust manifold or between the exhaust passages of the exhaust manifold can be achieved and, if necessary, can be compensated by correspondingly actuating the burner device.

The drive train for a motor vehicle according to the invention has the following advantages over conventional drive trains: improved exhaust gas heating is provided with simple measures and in a cost-effective manner. Furthermore, the exhaust manifold can also be heated directly or indirectly by means of the burner device. This heat can be transferred to the cylinder block, for example, via a cooling system of the internal combustion engine, so that the cold start behavior of the motor vehicle is significantly improved. By the higher exhaust gas temperatures achievable in this way, the operation of exhaust gas purification systems, such as, for example, catalysts, particle filters, etc., can be significantly improved, in particular at cold start. In addition, the burner has the following advantages: the burner may also be used in other engine operating points with increased exhaust enthalpy requirements. And thus may replace conventional secondary air systems.

According to a preferred development of the invention, it can be provided in the drive train that the burner device for burning fuel has a combustion chamber with an exhaust gas outlet for discharging exhaust gas from the combustion chamber, wherein the exhaust gas outlet is coupled in fluid communication with an exhaust gas channel of the exhaust manifold. In this preferred embodiment, the combustion chamber of the burner device is separated from the exhaust gas channel of the exhaust manifold. According to the invention, the combustion chamber can open directly into the exhaust gas channel of a cylinder of the exhaust manifold. Furthermore, it can be provided that the combustion chamber opens directly into the exhaust gas duct of the plurality of cylinders. Alternatively, an exhaust line may be formed between the combustion chamber and the exhaust channel for directing exhaust gases from the combustion chamber into the exhaust manifold. The exhaust line opens into an exhaust passage of the exhaust manifold, preferably in the vicinity of an exhaust valve of the cylinder head. Particularly preferably, the exhaust line is designed for directing exhaust gases from the combustion chamber into the entire exhaust channel of the exhaust manifold. According to the invention, it can be provided that a valve, in particular a shut-off valve or a check valve, is arranged between the combustion chamber and the exhaust gas duct of the exhaust manifold. Preferably, the opening of the exhaust gas outlet into the exhaust gas duct is directed counter to the flow direction of the exhaust gas of the internal combustion engine, so that the mixing of the exhaust gas is improved. Alternatively, the opening of the exhaust gas outlet can be arranged according to the invention perpendicular or oblique to the flow direction. According to the invention, an orientation in the flow direction is likewise possible. This orientation has the following advantages: suction effect (Sogwirkung) of exhaust gas from the cylinder to exhaust gas of the combustion chamber can be realized thereby. Such a burner device has the following advantages: a particularly uniform exhaust gas distribution as well as heat distribution can be achieved.

According to the invention, the burner device preferably has a fresh air inlet, wherein the fresh air inlet is coupled in fluid communication with an intake manifold of the drive train for supplying fresh air to the internal combustion engine in such a way that fresh air can be introduced into the burner device from the intake manifold. Preferably, an air inlet valve is arranged at the fresh air inlet, in particular in the region of the intake pipe, for controlling the air quantity conducted via the fresh air inlet. The air inlet valve is preferably controllable by an engine control device of the drive train, which is preferably configured for controlling the internal combustion engine. Via such a fresh air inlet, fresh air can be supplied to the burner device, in particular to the combustion chamber of the burner device, in a simple and cost-effective manner.

Furthermore, the burner arrangement is preferably designed for directing fresh air from the intake manifold directly into the exhaust gas duct of the exhaust manifold. This has the following advantages: the function of the secondary air system can thus be implemented in a simple manner and in a cost-effective manner. This may be advantageous for saving fuel, especially in case the drive train is operated at normal operating temperatures. Whereby the secondary air system can be completely replaced.

In a particularly preferred embodiment of the invention, it can be provided in the drive train that the burner device is arranged on the internal combustion engine. A direct heat transfer from the burner device to the internal combustion engine can thus be achieved by means of the mechanical coupling. In this case, it is preferred that the burner device is arranged in a region of the internal combustion engine in which rapid heat introduction is preferred, such as, for example, in the vicinity of an exhaust valve or exhaust valves. This arrangement has the following advantages: improving the heat utilization of the burner.

Preferably, the burner device is at least partially constructed in one piece with the engine block of the internal combustion engine. "integral" is to be understood within the scope of the present invention to mean, in particular, a single piece, an integral body or an irreversible connection to one another. In this case, the burner arrangement preferably has a cover which can be arranged or fastened on the engine block, for example, in order to laterally delimit the combustion chamber. The cover can be embodied, for example, in the exhaust manifold or as an additional component. This configuration has the following advantages: the production of the drive device is simplified, in particular because the geometric means required for the burner device can already be integrated into the casting mold and the casting core of the engine block and thus additional production steps for producing the burner device can be saved.

According to a preferred embodiment of the invention, the burner device is at least partially formed in one piece with the exhaust manifold. "integral" is to be understood within the scope of the present invention to mean, in particular, a single piece, an integral body or an irreversible connection to one another. In this case, the burner arrangement preferably has a cover which can be arranged or fastened, for example, on the exhaust manifold in order to laterally limit the combustion chamber. The covering can be embodied, for example, in the engine block or as an additional component. This configuration has the following advantages: the production of the drive device is simplified, in particular because the geometry required for the burner device can already be integrated into the casting mold and the casting core of the exhaust manifold, and thus additional production steps for producing the burner device can be saved.

Particularly preferably, the burner device has a fuel supply line for supplying fuel. The fuel supply line is preferably coupled in fluid communication with a fuel tank of the motor vehicle. According to the invention, it may be provided that the fuel supply line is coupled in fluid communication with the fuel pump for delivering liquid fuel. The fuel pump is preferably operable by means of an engine control device of the drive train, which is preferably configured for controlling the internal combustion engine. Alternatively or additionally, according to the invention, it may be provided that the fuel supply line is coupled in fluid communication with a tank ventilation system for ventilating the fuel tank. It is also contemplated in accordance with the present invention that the fuel supply line be coupled in fluid communication with an additional fuel source for providing an alternative fuel, such as, for example, methane. The fuel supply line has the following advantages: the combustion of the burner device can be controlled better with simple measures and in a cost-effective manner. The combustion of the fuel by means of the burner device can thereby take place independently of the operating state of the internal combustion engine. In this way, even in cold internal combustion engines, a defined operation of the burner device can be ensured by simple measures and in a cost-effective manner.

According to the invention, the burner device preferably has an ignition device that can be controlled separately from the internal combustion engine for the external ignition of the fuel. The ignition device is preferably controllable by means of an engine control device of the drive train, which is preferably designed for controlling the internal combustion engine. Such an ignition device has the following advantages: the combustion of the fuel by means of the burner device can be carried out independently of the operating state of the internal combustion engine. In this way, a proper operation of the burner device can be ensured even in cold internal combustion engines, using simple measures and in a cost-effective manner.

According to a second aspect of the invention, this object is achieved by a motor vehicle having a drive train with an internal combustion engine. According to the invention, the drive train is constructed as a drive train according to the invention.

All the advantages already described for the drive train for a motor vehicle according to the first aspect of the invention are obtained in the motor vehicle described. The motor vehicle according to the invention thus has the following advantages over conventional motor vehicles: improved exhaust gas heating is provided with simple measures and in a cost-effective manner. Furthermore, the exhaust manifold can also be heated directly or indirectly by means of the burner device. This heat can be transferred to the cylinder block, for example, via a cooling system of the internal combustion engine, so that the cold start behavior of the motor vehicle is significantly improved. By the higher exhaust gas temperatures achievable in this way, the operation of exhaust gas purification systems, such as, for example, catalysts, particle filters, etc., can be significantly improved, in particular at cold start. In addition, the burner has the following advantages: the burner may also be used in other engine operating points with increased exhaust enthalpy requirements. And thus may replace conventional secondary air systems.

Drawings

The drive train according to the invention and the motor vehicle according to the invention are explained further below with the aid of the drawings. Schematically:

FIG. 1 shows a detail of a preferred embodiment of a drive train according to the invention in a sectional view;

FIG. 2 shows a detail of the drive train from FIG. 1 in a sectional view from another viewing angle;

fig. 3 shows a preferred embodiment of the motor vehicle according to the invention in a side view.

Elements with the same function and mode of operation are provided with the same reference numerals in fig. 1 to 3, respectively.

Detailed Description

Fig. 1 schematically shows a detail of a preferred embodiment of a drive train 1 according to the invention in a sectional illustration. The drive train 1 has an internal combustion engine 3, whose cylinder head 14 with an exhaust manifold 5 is depicted in the figure. In the cylinder head 14, an intake valve 15 for admitting fresh air into the cylinder block 4 of the internal combustion engine 3 and an exhaust valve 16 for discharging exhaust gas from the cylinder block 4 are arranged. A plurality of cooling channels 17 are formed in the cylinder head 14. Furthermore, an exhaust gas outlet 9 of the burner device 6, which is only partially visible, is formed in the cylinder head 14. The exhaust outlet 9 opens into the exhaust channel 7 of the exhaust manifold 5 in the region of the exhaust valve 16 and is directed toward the exhaust valve 16. The exhaust gas outlet 9 is thus directed counter to the flow direction of the exhaust gas away from the cylinder 4.

Fig. 2 shows a detail of the drive train 1 from fig. 1 schematically in a sectional illustration from another viewing angle. In this view, four cylinders 4 of the internal combustion engine 3 are visible, arranged in a row, which are coupled in fluid communication with an intake pipe 11 for receiving fresh air. The fresh air inlet 10 of the burner device 6 is likewise coupled in fluid communication with an intake pipe 11. At the fresh air inlet 10 a check valve 18 is arranged for preventing a fluid flow from the burner device 6 into the intake pipe 11. The burner device 6 is essentially formed in the exhaust manifold 5 and has a combustion chamber 8 into which a fresh air inlet 10 for introducing fresh air and a fuel supply line 12 for introducing fuel open. Furthermore, the burner device 6 has an ignition device 13 arranged at the combustion chamber 8 for igniting the fuel-air mixture. The exhaust gas outlet 9 of the burner arrangement 6 is coupled in fluid communication with the combustion chamber 8 and is thus configured for directing exhaust gas from the combustion chamber 8 into the exhaust gas channel 7 of the exhaust manifold 5 associated with the different cylinders 4.

Fig. 3 schematically shows a preferred embodiment of a motor vehicle 2 according to the invention in a side view. The motor vehicle 2 has a drive train 1 according to the invention with an internal combustion engine 3. A burner device 6 is arranged at an exhaust manifold 5 of the internal combustion engine 3.

List of reference numerals

1 drive train

2 Motor vehicle

3 internal combustion engine

4 cylinder body

5 exhaust manifold

6 burner device

7 exhaust channel

8 combustion chamber

9 exhaust outlet

10 fresh air intake

11 air inlet pipe

12 fuel supply line

13 ignition device

14 cylinder cover

15 air inlet valve

16 air exhaust valve

17 cooling channel

18 check valve

Claims

1. A drive train (1) for a motor vehicle (2) has: an internal combustion engine (3) having a plurality of cylinders (4), a piston which is guided linearly in the cylinders (4), and an exhaust manifold (5) for collecting exhaust gases which emerge from the cylinders (4); and a burner device (6) for combusting fuel outside the cylinder (4) for generating heat, characterized in that the burner device (6) is coupled in fluid communication with the exhaust manifold (5) in such a way that exhaust gas can be conducted from the burner device (6) into an exhaust channel (7) of the exhaust manifold (5).

2. Drive train (1) according to claim 1, characterized in that the burner device (6) for burning fuel has a combustion chamber (8) with an exhaust gas outlet (9) for discharging exhaust gas from the combustion chamber (8), wherein the exhaust gas outlet (9) is coupled in fluid communication with an exhaust gas channel (7) of the exhaust manifold (5).

3. Drive train (1) according to claim 1 or 2, characterized in that the burner device (6) has a fresh air inlet (10), wherein the fresh air inlet (10) is coupled in a fluid-communicating manner with an intake pipe (11) of the drive train (1) for supplying fresh air to the internal combustion engine (3) in such a way that fresh air can be introduced from the intake pipe (11) into the burner device (6).

4. Drive train (1) according to claim 3, characterized in that the burner arrangement (6) is configured to direct fresh air from the inlet line (11) directly into the exhaust channel (7) of the exhaust manifold (5).

5. Drive train (1) according to any one of the preceding claims, characterized in that the burner arrangement (6) is arranged at the internal combustion engine (3).

6. Drive train (1) according to claim 5, characterized in that the burner arrangement (6) is at least partially constructed in one piece with an engine block of the internal combustion engine (3).

7. Drive train (1) according to claim 5 or 6, characterized in that the burner device (6) is at least partially constructed in one piece with the exhaust manifold (5).

8. Drive train (1) according to any one of the preceding claims, characterized in that the burner device (6) has a fuel supply line (12) for supplying fuel.

9. Drive train (1) according to any one of the preceding claims, characterized in that the burner device (6) has an ignition device (13) which can be controlled separately from the internal combustion engine (3) for the external ignition of fuel.

10. A motor vehicle (2) with a drive train (1) having an internal combustion engine (3), characterized in that the drive train (1) is constructed according to any one of claims 1 to 9.