DE102013020999A1 - Fuel supply device for an internal combustion engine of a motor vehicle - Google Patents

Abstract

The invention relates to a fuel supply device (15) for an internal combustion engine (10) of a motor vehicle, having at least one fuel tank (30) for storing liquid fuel, with at least one adsorption filter (32) fluidically connected to the at least one first line (34) Fuel tank (30) and via at least one second conduit (38) is fluidly connected to an intake tract (14) of the internal combustion engine (10), wherein in the second conduit (38) at least one sensor (48, 58) is arranged, by means of which a Hydrocarbon concentration in which by means of the pump (50) and conveyed by the adsorption filter (32) through the second line (38) into the intake tract (14) flowing gas flow is detected.

Description

The invention relates to a fuel supply device for an internal combustion engine of a motor vehicle according to the preamble of patent claim 1.

Fuel supply devices for internal combustion engines of motor vehicles are already well known, for example, from production vehicle production. Such a fuel supply device is usually used to introduce liquid fuel into at least one combustion chamber, in particular a cylinder, of an internal combustion engine. For this purpose, the fuel supply device comprises at least one fuel tank for storing liquid fuel.

The liquid fuel includes volatile fuel components, collectively referred to as "fuel vapors." These fuel vapors gasses from the liquid fuel. Such outgassing occurs, in particular, when the internal combustion engine is deactivated over a relatively long period of time or is not supplied with liquid fuel from the fuel tank.

In order to avoid excessive emissions of unburned hydrocarbons (HC), it is known to employ at least one adsorption filter in such fuel supply devices. Such an adsorption filter is, for example, an activated carbon filter which serves for filtering and collecting fuel vapors.

The outgassing of the liquid fuel received in the fuel tank produces gas containing the fuel vapors. This gas can, for example, be passed through the adsorption filter, wherein the fuel vapors contained in the gas, in particular the unburned hydrocarbons, are at least partially filtered out of the gas by means of the adsorption filter. As a result of this filtering and capturing of the fuel vapors, the adsorption filter or a filter material of the adsorption filter is loaded with fuel vapors, that is to say with unburned hydrocarbons. As the load increases, the ability of the adsorption filter to filter and capture hydrocarbons decreases.

Therefore, a regeneration of the adsorption filter is provided. As part of such regeneration, a gas stream, in particular air, is passed through the adsorption filter. This gas or air stream absorbs the fuel components received in the adsorption filter, so that the adsorption filter is purged. The gas stream with the fuel components now contained therein (unburned hydrocarbons) is introduced into an intake tract of the internal combustion engine and fed via the intake to the at least one combustion chamber of the internal combustion engine, so that the unburned hydrocarbons take part in at least one running in the combustion chamber combustion and thus burned.

For generating or effecting the gas flow for regenerating the adsorption filter, the internal combustion engine is usually used, which is designed for example as a reciprocating internal combustion engine and sucks in air during its operation. This suction of air can be used to generate the gas flow. To realize a fast regeneration of the adsorption filter, it is advantageous to pass a high amount of gas through the adsorption filter in a short time.

In modern powertrains, however, it may happen that the internal combustion engine is not or not always, when regeneration of the adsorption filter is required, for regenerating the adsorption filter can be used, for example, because the internal combustion engine is deactivated, although the car is in total operation. This is the case, for example, in hybrid vehicles, wherein the motor vehicle is driven by means of at least one electric motor while the internal combustion engine is deactivated.

Then, by means of the internal combustion engine, no gas flow can be generated for the regeneration of the adsorption filter. Furthermore, it can be provided that due to an increasing de-throttling of the intake tract, at least in some operating ranges, an insufficient mass flow of the gas flow for regenerating the adsorption filter by means of the internal combustion engine can be generated. Even with direct injection gasoline engines, in particular, if such a gasoline engine is operated with a stratified combustion process, only an insufficient mass flow of the gas stream may be available in order to regenerate the adsorption filter can.

To solve this problem, it is known to use at least one auxiliary pump, by means of which a gas stream for regeneration of the adsorption filter can be generated or effected.

Of the DE 198 13 321 B4 is a fuel supply device for an internal combustion engine of a motor vehicle to take as known. The fuel supply device comprises at least one fuel tank for storing liquid fuel and at least one adsorption filter, which is fluidly connected via at least one first line to the fuel tank and via at least one second line fluidly connected to an intake tract of the internal combustion engine. The fuel supply device furthermore comprises at least one pump as the aforementioned auxiliary pump, by means of which a gas flow for regenerating the adsorption filter is to be conveyed through it and into the intake tract.

The fuel components (fuel vapors) contained in the gas stream are transported into at least one combustion chamber, in particular a cylinder, of the internal combustion engine. In addition, in a fired operation of the internal combustion engine, liquid fuel is introduced from the fuel tank into the combustion chamber by means of at least one injection element. This fuel is for example injected directly into the combustion chamber by means of the injection element. Since both fuel passes into the combustion chamber by means of the injection element as well as via the gas flow, the fuel components passing through the gas flow into the combustion chamber in the combustion chamber can undesirably affect the combustion processes occurring. It has been shown that this can lead to an undesirable exhaust gas composition and in the worst case to an influence on the driveability.

Object of the present invention is therefore to develop a fuel supply device of the type mentioned in such a way that these problems can be avoided.

This object is achieved by a fuel supply device having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the remaining claims.

In order to develop a fuel supply device specified in the preamble of claim 1 type such that can be avoided unwanted and caused by the gas flow to regenerate the adsorber impairments of combustion of the internal combustion engine, it is inventively provided that in the second conduit, via which the adsorption filter fluidly is connected to the intake, at least one sensor is arranged, by means of which a hydrocarbon concentration in the conveyed by the pump and from the adsorption through the second line into the intake air flowing gas stream is detected. In other words, the sensor is designed as a hydrocarbon sensor (HC sensor) by means of which at least one value is detected which characterizes the hydrocarbon concentration or the hydrocarbon content in the gas stream flowing into the intake tract via the second line.

By detecting the hydrocarbon concentration in the gas stream, it is possible, for example, to set a quantity of the liquid fuel to be introduced into at least one combustion chamber of the internal combustion engine by means of at least one injection element as a function of the detected hydrocarbon concentration. This is possible because the hydrocarbon concentration in the gas stream before entering the combustion chamber can be determined by means of the sensor. This makes it possible to avoid negative influences on the combustion in the combustion chamber, and in addition, the fuel contained in the gas stream or the fuel components contained in the gas stream can be used very effectively, which in addition fuel savings can be effected especially in heavily loaded adsorption.

In other words, it is possible to set a total amount of the fuel to be introduced into the combustion chamber in a particularly precise manner, this total amount comprising the fuel constituents contained in the gas flow and the amount of the fuel introduced into the combustion chamber by means of the injection element. Due to the precise adjustment of the total amount, a particularly effective and efficient combustion can be realized.

Moreover, with the fuel supply device according to the invention, it is possible to regenerate the adsorption filter, which is designed, for example, as an activated carbon filter, at least substantially independently of a suction vacuum that can be effected by means of the internal combustion engine in the intake tract, so that, for example, even in the case of fully de-throttled operation, during operation Charging and in a shift operation of trained as a gasoline engine, for example internal combustion engine, the adsorption effectively cleaned, that can be regenerated. It is in fact possible, by means of the pump, to effect the gas flow for regenerating the adsorption filter at least substantially independently of a pressure prevailing in the intake tract. Thus, an advantageous regeneration of the adsorption filter can be realized even if the motor vehicle is designed as a hybrid vehicle, in particular as a plug-in hybrid, and / or if the internal combustion engine is designed as a direct injection gasoline engine, which is operated in a stratified operation.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or shown in the single figure alone can be used not only in the respectively indicated combination but also in other combinations as well as alone, without the frame to leave the invention.

The drawing shows in the figure a schematic representation of an internal combustion engine for a motor vehicle, with a fuel supply device for supplying the internal combustion engine with liquid fuel, wherein the fuel supply device comprises at least one sensor by means of which a hydrocarbon concentration in a pumped by a pump and by an adsorption can be detected by a line in an intake of the internal combustion engine gas stream flowing.

The figure shows a schematic representation of an internal combustion engine 10 for a motor vehicle. The internal combustion engine 10 is designed as a reciprocating internal combustion engine and in the present case comprises four combustion chambers in the form of cylinders 12 , As can be seen from the figure, the internal combustion engine 10 in the present case designed as a series four-cylinder engine. The internal combustion engine 10 serves to drive the example designed as a passenger cars motor vehicle and is designed for example as direct injection gasoline engine. The motor vehicle is designed, for example, as a hybrid vehicle and in particular as a plug-in hybrid. Here, the motor vehicle comprises at least one not visible in the figure electric motor, which also serves to drive the motor vehicle.

The internal combustion engine 10 includes a whole with 14 designated intake, via which the internal combustion engine 10 aspirates air during its operation. In the intake tract 14 is an air filter 16 arranged to filter the sucked air.

From the figure is also a whole with 15 designated fuel supply device shown. The fuel supply device 15 includes injectors in the form of injectors. Each of the cylinders 12 is assigned to one of the injectors. The respective injectors serve for the direct injection of liquid fuel into the cylinder 12 , By injecting the liquid fuel and sucking the air is produced in the respective cylinders 12 a fuel-air mixture, which is ignited for example by means of a respective spark plug and thereby burns. This combustion results in exhaust gas coming from the cylinders 12 by means of an exhaust tract 18 the internal combustion engine 10 is dissipated. In the exhaust tract 18 is an exhaust manifold 20 arranged, which can be flowed through by the exhaust gas.

The internal combustion engine 10 Also includes at least one exhaust gas turbocharger having a turbine, not shown in the figure. The turbine is in the exhaust tract 18 arranged and driven by the exhaust gas. Furthermore, the exhaust gas turbocharger comprises a compressor 22 which is in the intake tract 14 is arranged. The compressor 22 is driven by the turbine and serves to compress air. In the flow direction of the air through the intake tract 14 is downstream of the compressor 22 a throttle 24 in the intake tract 14 arranged. The throttle 24 serves to adjust one in the intake tract 14 Actuating pressure. Alternatively or additionally, the throttle serves 24 to one, the cylinders 12 Adjust the amount of air to be supplied. In the intake tract 14 is also a suction tube 26 arranged, by means of which the compressed air to the cylinder 12 is distributed.

As the internal combustion engine 10 while sucking in air, causes the internal combustion engine 10 in the intake manifold 26 a negative pressure, which is also referred to as Saugrohrunterdruck.

From the figure is also a vent line 28 recognizable. The vent line 28 is part of a so-called crankcase ventilation, by means of which so-called blow-by gas from a crankcase of the internal combustion engine 10 discharged and into the intake tract 14 is returned.

The fuel supply device 15 includes at least one fuel tank 30 for storing liquid fuel. The liquid fuel can be injected directly into the cylinders via the injectors 12 be injected. The fuel supply device 15 moreover comprises an adsorption filter in the form of an activated carbon filter 32 ,

Will the internal combustion engine 10 not operated for a long time and therefore not for a long time with liquid fuel from the fuel tank 30 supplied, so can in the fuel tank 30 a gas is created because of the fuel tank 30 absorbed liquid fuel has volatiles that can outgas. The gas resulting from the outgassing of the liquid fuel contains volatile fuel components or fuel vapors from unburned hydrocarbons (HC). To an undesirable increase in pressure in the fuel tank 30 to Avoid this generated gas from the fuel tank 30 dissipated. For example, the gas is discharged to the environment of the motor vehicle.

However, in order to avoid excessive emission of unburned hydrocarbons, the fuel supply device comprises 15 the activated carbon filter 32 , From the figure it can be seen that the activated carbon filter 32 via a first line 34 fluidly with the fuel tank 30 connected is. About the line 34 can the gas from the fuel tank 30 discharged and the activated carbon filter 32 be supplied. The activated carbon filter 32 serves to filter and capture the fuel vapor or the unburned hydrocarbons from the gas. In other words, the unburned hydrocarbons by means of the activated carbon filter 32 at least predominantly filtered from the gas before the gas via a vent line 36 can be discharged to the environment.

With increasing filtering and capturing of unburned hydrocarbons, the activated carbon filter becomes 32 increasingly loaded with unburned hydrocarbons. As the load increases, the ability of the activated carbon filter decreases 32 to filter and capture unburned hydrocarbons. Therefore, a regeneration of the activated carbon filter 32 required.

From the figure it can be seen that the activated carbon filter 32 via at least a second line 38 fluidic with the intake tract 14 the internal combustion engine 10 connected is. The fuel supply device 15 includes a conduit 40 , which on the one hand with the suction pipe 26 and on the other hand with the line 38 is fluidically connected. In the line 40 is a regeneration valve 42 arranged. Further, in the line 40 a sensor 44 and a check valve 46 arranged. The sensor 44 is designed as an HC sensor.

Exceeds the loading of the activated carbon filter 32 For example, a predefinable threshold, so for example, the regeneration valve 42 open. This will make the activated carbon filter 32 fluidic with the suction tube 26 connected. There - as described - in the intake manifold 26 in the fired operation of the internal combustion engine 10 A negative pressure is generated, by means of the negative pressure in the activated carbon filter 32 contained, unburned hydrocarbons are sucked, causing the activated carbon filter 32 is regenerated. The unburned hydrocarbons flow into the cylinders 12 and are burned.

In other words, a so-called Regeneriergasstrom is generated by means of the negative pressure, by means of which the unburned hydrocarbons from the activated carbon filter 32 discharged and the cylinders 12 be supplied. In the line 38 is a sensor 48 arranged, by means of which the mass flow of Regeneriergasstroms and / or the temperature of the Regeneriergasstroms can be detected.

Will the internal combustion engine 10 for example, operated with a stratified combustion process and / or strong Entschrosselung of the intake 14 It may happen that in the intake manifold 26 producible negative pressure not for a sufficient regeneration of the activated carbon filter 32 sufficient.

Nevertheless, an effective and efficient regeneration of the activated carbon filter 32 to effect is in the second line 38 a pump 50 arranged. The pump 50 is used as an auxiliary pump or regenerating pump, as by means of the pump 50 a gas stream for regenerating the activated carbon filter 32 through it and into the intake tract 14 to promote. The pump 50 is based on the flow direction of the gas flow from the activated carbon filter 32 to the intake tract 14 between the activated carbon filter 32 and the intake tract 14 arranged. From the figure it can be seen that the pump 50 downstream of the activated carbon filter 32 and upstream of the intake tract 14 is arranged. By means of the pump 50 can thus be independent of one in the intake manifold 26 prevailing negative pressure in the activated carbon filter 32 contained, unburned hydrocarbons sucked in and from the activated carbon filter 32 through the pump 50 through to the intake tract 14 be encouraged.

The pump 50 is with a temperature sensor 52 equipped, so that by means of the temperature sensor 52 the temperature of the gas stream can be detected. Upstream of the pump 50 and downstream of the activated carbon filter 32 , in particular downstream of the sensor 48 , is a relative pressure sensor 54 arranged. Downstream of the pump 50 and upstream of the intake tract 14 is another relative pressure sensor 56 arranged. By doing that the pump 50 in the path between the activated carbon filter 32 and the internal combustion engine 10 or the intake tract 14 is arranged, tank valves are not provided and not required. Thus, the fuel supply device 15 a low number of parts, low cost, low weight and a small space requirement. Furthermore, that of the activated carbon filter 32 discharged hydrocarbons gas stream contained the cylinders 12 fed, leaving the activated carbon filter 32 discharged, unburned hydrocarbons are burned and not released unburned to the environment.

It can also be seen from the figure that in the second line 38 a sensor 58 is arranged which is also designed as an HC sensor, that is, as a hydrocarbon sensor. By means of the sensor 44 is a hydrocarbon concentration in which the line 40 detectable by flowing Regeneriergasstrom. By means of the sensor 58 is a hydrocarbon concentration in the by means of the pump 50 funded and from the activated carbon filter 32 through the second line 38 in the intake tract 14 can be detected flowing gas stream. This means that the hydrocarbon concentration or the hydrocarbon content in the by means of the pump 50 generated gas stream can be detected and determined before the hydrocarbons through the gas flow into the cylinder 12 be initiated and participate in the respective burns.

The sensors 44 and 58 in each case provide at least one signal, wherein this respective signal characterizes the detected hydrocarbon concentration in the gas stream or in the Regeneriergasstrom. The fuel supply device 15 is designed to be by means of the respective injectors in the cylinder 12 amount of liquid fuel to be injected as a function of that of the sensors 44 and 58 to set the signals provided. In other words, those from the sensors 44 . 58 provided signals are used as information for the pilot control of the injection amount of the liquid fuel. Thus, a total amount of in the cylinder 12 be adjusted very precisely, this total amount includes the hydrocarbons passing through the line 38 and / or the line 40 in the cylinders 12 be introduced. Further, the total amount includes the amount of fuel that enters the cylinders through the injectors 12 is injected.

Overall, it is in the fuel supply device 15 thus provided, the pump 50 as a purge pump to provide a particularly high amount of gas or a particularly high gas mass flow to the activated carbon filter 32 to clean. In addition, the concentration of hydrocarbons by means of the pump 50 sucked in gases by means of the sensor 58 before entering the cylinder 12 measured. Here are the positions of the pump 50 and the sensor 58 and optionally the sensor 44 freely selectable, that is they can independently before or after the activated carbon filter 32 be positioned.

Preferably, the pump 50 for generating an overpressure or underpressure in the fuel supply device 15 used to thereby improve the tightness of the fuel tank 30 as part of an on-board diagnostic (OBD - on-board diagnostics) review.

As can be seen from the figure, the sensor 48 , the pump 50 , the sensor 58 , the regeneration valve 42 and the sensor 44 via a vehicle electrical system 60 with a control unit for regulating or controlling the fuel supply device 15 connected. Alternatively or additionally, the sensor 48 be designed as HC sensor, so that by means of the sensor 48 a hydrocarbon concentration of a pipe 38 and thus the sensor 48 flowing gas can be detected.

LIST OF REFERENCE NUMBERS

10

Internal combustion engine

12

cylinder

14

intake system

15

Fuel supply

16

air filter

18

exhaust tract

20

exhaust manifold

22

compressor

24

throttle

26

suction tube

28

vent line

30

Fuel tank

32

Activated carbon filter

34

first line

36

vent line

38

second line

40

line part

42

regenerating

44

sensor

46

check valve

48

sensor

50

pump

52

temperature sensor

54

Relative pressure sensor

56

Relative pressure sensor

58

sensor

60

board network

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19813321 B4 [0011]

Claims (4)

Fuel supply device ( 15 ) for an internal combustion engine ( 10 ) of a motor vehicle, with at least one fuel tank ( 30 ) for storing liquid fuel, with at least one adsorption filter ( 32 ), which via at least a first line ( 34 ) fluidly with the fuel tank ( 30 ) and via at least one second line ( 38 ) fluidically with an intake tract ( 14 ) of the internal combustion engine ( 10 ), characterized in that in the second line ( 38 ) at least one sensor ( 48 . 58 ) by means of which a hydrocarbon concentration in the by means of the pump ( 50 ) and from the adsorption filter ( 32 ) through the second line ( 38 ) in the intake tract ( 14 ) flowing gas stream is detected. Fuel supply device ( 16 ) according to claim 1, characterized in that the pump ( 50 ) based on the flow direction of the gas stream from the adsorption filter ( 32 ) to the intake tract ( 14 ) between the adsorption filter ( 32 ) and the intake tract ( 14 ) is arranged. Fuel supply device ( 16 ) according to one of claims 1 or 2, characterized in that the fuel supply device ( 16 ) at least one injection element for introducing a predeterminable amount of liquid fuel from the fuel tank ( 30 ) in at least one combustion chamber ( 12 ) of the internal combustion engine ( 10 ), wherein the fuel supply device ( 16 ) is adapted to the amount of the liquid fuel in dependence on at least one of the sensor ( 48 . 58 ) and adjust the detected hydrocarbon concentration characterizing signal. Method for operating a fuel supply device ( 16 ) according to any one of the preceding claims.

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