DE102015225126A1 - Tank ventilation system, drive and vehicle - Google Patents

Abstract

The present invention relates to a tank ventilation system (1) for an internal combustion engine (10) of a vehicle (100), having a filter unit (20) for receiving and storing fuel vapors from a fuel tank (30) of the vehicle (100), a rinse line arrangement (40). for the fluid-mechanical connection of the filter unit (20) to a suction line arrangement (60) of the internal combustion engine (10) of the vehicle (100) and a regeneration valve unit (50) for controlling the fluid-mechanical connection of the filter unit (20) to the suction line arrangement (60) through the purge line arrangement ( 40), wherein the regeneration valve unit (50) has a plurality of fluid-mechanically connected in parallel regeneration valves (51).

Description

State of the art

The present invention relates to a tank ventilation system for an internal combustion engine of a vehicle, a drive system for a vehicle and a vehicle with the drive system.

In order to meet emission limit values, vehicles with internal combustion engine are equipped with a tank ventilation system in connection with the necessary fuel tank. The tank ventilation system comprises a vent line from the tank of the fuel tank, which ends in a filter, in particular in an activated carbon filter. The filter absorbs hydrocarbons from the fuel vapors escaping from the tank, allowing exhaust air cleaned by hydrocarbons to escape into the atmosphere. The underlying filter system must be generated. For this purpose, the filter system is usually connected by means of a purge line to the intake manifold of the underlying internal combustion engine. The fluid mechanical connection is controlled via a regeneration valve in the purge line.

A disadvantage of this approach that the regeneration and purge flows lead to increased fuel input from the tank ventilation system in the fuel path, which may also lead to difficult to control mixture deviations.

Disclosure of the invention

The tank ventilation system according to the invention with the features of claim 1 has the advantage that a particularly uniform distribution of the introduced from the tank ventilation system fuel to the internal combustion engine and the cylinder is achieved with a particularly reliable level of controllability. This is inventively achieved with the features of independent claim 1, characterized in that a tank ventilation system for an internal combustion engine of a vehicle is provided with (i) a filter unit for receiving and storing fuel vapors from a fuel tank of the vehicle, (ii) a Spülleitungsanordnung for fluid mechanical connection of A filter unit having a suction line arrangement of the internal combustion engine of the vehicle and (iii) a regeneration valve unit for controlling the fluid mechanical connection of the filter unit with the suction line arrangement through the rinse line arrangement. In this case, the regeneration valve unit has a plurality of regeneration valves connected to one another in a fluid-mechanically parallel manner. Characterized in that a plurality of regeneration valves is formed in the Regenerierventileinheit, which are connected in fluid-mechanical parallel to each other, a particularly high degree of controllability of the supply of fuel from the tank ventilation process and a high degree of uniformity of the distribution with respect to the internal combustion engine can be achieved.

The dependent claims show preferred developments of the invention.

In an advantageous development of the tank ventilation system according to the invention, the flushing line arrangement has a flushing line with a plurality of partial lines. Furthermore, in each case a regeneration valve is formed in a sub-line and each sub-line is fluid-mechanically connected or connectable independently of other sub-lines with the Saugleitungsanordnung of the internal combustion engine.

By an appropriate arrangement of the sub-pipes with respect to the internal combustion engine and the internal combustion engine with air supplying suction line arrangement, the entry of fuel from the tank ventilation process in the fuel path of the internal combustion engine can be particularly balanced.

It is particularly advantageous if, according to a preferred embodiment of the tank ventilation system according to the invention in each case at least one regeneration valve for each of the groups of cylinders is formed in a plurality of groups of cylinders of the internal combustion engine. In this way, the fuel input from the tank ventilation process can be evenly distributed over cylinder groups, in particular also different cylinder banks.

In another advantageous development of the tank ventilation system according to the invention, an increased degree of uniformity of the fuel supplied from the tank ventilation process can be achieved in the distribution by forming a plurality of regeneration valves for each of the groups of cylinders for a plurality of groups of cylinders of the internal combustion engine, in particular in identical ones Number.

In addition, a particularly high degree of tuning in relation to the operation of the underlying internal combustion engine can be achieved if, according to a development of the tank ventilation system according to the invention, which at least one regeneration valve is designed for each cylinder of the internal combustion engine.

This effect can be further increased if, in each case, a plurality of regeneration valves are formed for each cylinder of the internal combustion engine, in particular with an identical number for each of the cylinders.

The assignment between a regeneration valve to a respective cylinder of the underlying internal combustion engine can be implemented particularly reliably if a respective regeneration valve is formed upstream and in the immediate vicinity of an inlet valve of a respective cylinder. Particularly advantageous is the short path of the regeneration or the regeneration gases to the inlet valve of the cylinder, because thereby optimal synchronization of the flush timing of the regeneration valve and the intake frequency of the cylinder is made possible.

According to a further development of the tank ventilation system according to the invention, it is provided that for a cylinder of the internal combustion engine, a first regeneration valve is formed upstream and in the immediate vicinity of an inlet valve of the respective cylinder and another Regenerierventil upstream and spaced from the inlet valve of the cylinder and the first regeneration valve is formed ,

In this way, the supply of fuel from the tank venting process can be particularly well matched to the influx of air on the intake tract, especially at higher suction frequencies of the cylinder.

In order to be able to meet the emissions protection requirements particularly reliably, it is advantageous if the supply of fuel from the tank ventilation process is coordinated with respect to the operation of the units involved.

To realize this, it is provided in a preferred development of the tank ventilation system according to the invention that a control unit is provided, which is arranged to control the Regenerierventileinheit and the regeneration valves and thus the fluid mechanical connection of the filter unit with the suction line through the purge line, in particular depending on a Operating status of a drive system of the vehicle, an operating state of the internal combustion engine of the vehicle, a status of the filter unit and / or environmental conditions.

Furthermore, the present invention relates to a drive system for a vehicle with (i) an internal combustion engine for driving a vehicle, (ii) a fuel tank for receiving fuel and for controllably supplying the internal combustion engine with fuel and (iii) tank venting system for controllable fluid mechanical connection between the Fuel tank and a Saugleitungsanordnung of the internal combustion engine, in which a tank ventilation system is formed according to the present invention.

Furthermore, the present invention provides a vehicle which is formed with a drive system according to the invention.

Brief description of the figures

Embodiments of the invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view in the manner of a block diagram showing an embodiment of the vehicle according to the invention using an embodiment of the tank ventilation system according to the invention, and

2 shows a schematic view in the manner of a block diagram, a conventional tank ventilation system.

Preferred embodiments of the invention

The following are with reference to the 1 Embodiments of the invention described in detail. Identical and equivalent as well as equivalent or equivalent elements and components are designated by the same reference numerals. Not in every case of their occurrence, the detailed description of the designated elements and components is reproduced.

The illustrated features and other properties can be isolated in any form of each other and combined with each other, without departing from the gist of the invention.

Before going into detail on embodiments of the present invention, briefly, a conventional tank ventilation system 1' be described, which in 2 is shown.

In the arrangement according to 2 is the conventionally constructed tank ventilation system 1' between a fuel tank 30 and a suction pipe part 65 a suction line arrangement 60 an internal combustion engine 10 trained, which is referred to below as an internal combustion engine.

The fuel tank 30 itself consists of a tank housing 33 for receiving the fuel, a filler neck 31 for filling the fuel tank 30 and a tank vent line 32 , The tank vent line 32 connects the fuel tank 30 Fluidmechanisch with the filter unit 20 ,

Opposite is the suction line part 65 as part of the suction line arrangement 60 upstream of the combustion engine 10 with the cylinder bank 11 and the cylinders 12 and downstream to a charge air cooler 62 and a throttle 63 educated. Downstream of the combustion engine 10 is the exhaust aftertreatment 70 with an exhaust pipe 71 and a sensor device formed on or in the same 72 , for example, a lambda probe or the like.

To get out of the fuel tank 30 Before the communication with the atmosphere to be able to filter out harmful components, for example hydrocarbons, is the tank ventilation line 32 Fluidmechanisch with the filter unit 20 connected, which of a filter housing 21 is formed, inside which a filter 22 , for example, an activated carbon filter, located above the tank vent line 32 supplied gaseous air fuel mixture, for example, freed from hydrocarbon components. The purified gas mixture then leaves via the environmental line 23 the filter unit 20 ,

To a busy filter 22 to regenerate, so to clean, is the environmental line 23 opposite a purge line unit 40 formed, which controlled by a regeneration valve 51 a controlled fluid mechanical connection with the suction line part 65 the suction line arrangement 60 manufactures. The conventional purge line unit 40 ' is from one in relation to the regeneration valve 51 upstream purge line 44 and a downstream purge line 45 with mouth 46 on and in the suction line part 65 educated.

Conventionally, the mouth is 46 the conventional purge line unit 40 together with the suction line part 65 significantly upstream of the engine 10 in the suction line arrangement 60 educated.

• – Die erfindungsgemäße Spülleitungseinheit 40 besteht im Wesentlichen aus einer Spülleitung 41, die bis in die Nähe der Brennkraftmaschine 10 reicht und sich dort in der Nähe an einer Verzweigungsstelle 43 in eine Mehrzahl von Teilleitungen 42 aufteilt.
• – Jede Teilleitung 42 weist genau ein Regenerierventil 51 auf, so dass insgesamt – im Gegensatz zum herkömmlichen Tankentlüftungssystem 1‘ gemäß 2 – eine Mehrzahl von Regenerierventilen 51 in fluidmechanischer Parallelanordnung, nämlich über die Teilleitungen 42 ausgebildet ist.
• – Jede Teilleitung 42 besitzt ihren eignen Mündungsbereich 47.
• – Der jeweilige Mündungsbereich 47 liefert die fluidmechanische Verbindung der jeweiligen Teilleitung 42 mit dem jeweiligen Regenerierventil 51 darin, und zwar in unmittelbarer Nähe des Einlasses und insbesondere des Einlassventiles für einen jeweiligen Zylinder 12 der Zylindergruppe 11 des Verbrennungsmotors 10.
• – Jeder Mündungsbereich 47 ist jeweils in einer Teilsaugleitung 61 in unmittelbarer Nähe des Verbrennungsmotors 10 und dessen Einlass ausgebildet.

In contrast, in the embodiment according to the invention of the tank ventilation system 1 which is in 1 in a vehicle according to the invention 100 is formed, the following differences:

• - The flushing line unit according to the invention 40 consists essentially of a purge line 41 that are close to the internal combustion engine 10 reaches and is close by at a branching point 43 in a plurality of sub-lines 42 divides.
• - Each sub-line 42 has exactly one regeneration valve 51 on, so that in total - in contrast to the conventional tank ventilation system 1' according to 2 - A plurality of regeneration valves 51 in fluid-mechanical parallel arrangement, namely on the sub-lines 42 is trained.
• - Each sub-line 42 has its own mouth area 47 ,
• - The respective mouth area 47 supplies the fluid mechanical connection of the respective sub-line 42 with the respective regeneration valve 51 in, in the immediate vicinity of the inlet and in particular the intake valve for a respective cylinder 12 the cylinder group 11 of the internal combustion engine 10 ,
• - Each mouth area 47 is in each case in a Teilaugleitung 61 in the immediate vicinity of the internal combustion engine 10 and its inlet formed.

At the in 1 shown embodiment of the tank ventilation system according to the invention 1 is thus for each of the four cylinders 12 an individual supply of fuel from the tank ventilation process in a controlled manner possible.

To control this process is a control unit according to the invention 80 educated.

This has a plurality of measuring and control lines 81 . 82 . 83 and 84 on to readings and / or control signals with the filter unit 20 , the regeneration valves 51 , the internal combustion engine 10 and its units and / or the transmission 92 to be able to exchange.

The gear 92 , whose two drive trains 91 and 92 and the internal combustion engine 10 make up the drive 90 of the vehicle according to the invention 100 out 1 , This also consists of a chassis 101 and wheels 102 ,

Also, the control unit 80 via the measuring and control line 83 on an exhaust gas sensor 72 , for example, a lambda probe in the exhaust pipe 71 the exhaust aftertreatment system 70 be connected.

The hot film air mass meter 64 , Also referred to as HFM unit, the detection is used in the intake manifold of the internal combustion engine 10 incoming fresh air for combustion.

The throttle adjustment 63 , also referred to as DV-E unit, is eg electrically operated and serves to control the in the intake manifold of the internal combustion engine 10 incoming fresh air for combustion.

• – Aktivkohlefilter (AKF) als Filter 22 zur Absorption der aus dem Tank 30 entweichenden Kraftstoffdämpfe,
• – Tankentlüftungsventil TEV als Regenerierventil 51 und
• – entsprechenden Leitungen 32, 40, 41, 44, 45.

These and other features and characteristics of the present invention will be further elucidated with reference to the following statements:
Tank Evaporation Systems will be used to comply with Evaporation Emission Limits 1 . 1' used, as in the 1 and 2 are shown. These consist among other things of the following main components:

• - Activated carbon filter (AKF) as a filter 22 for absorption from the tank 30 escaping fuel vapors,
• - Tank ventilation valve TEV as a regeneration valve 51 and
• - corresponding lines 32 . 40 . 41 . 44 . 45 ,

The vent line 32 from the fuel tank 32 ends in the filter unit 20 and in the charcoal canister. There are the hydrocarbons from the tank 30 escaping fuel vapors absorbed, leaving only purified air through the environmental pipe 23 escapes into the atmosphere.

To the activated carbon of the filter 22 to regenerate, leads another line arrangement 40 from the filter unit 20 and the charcoal canister to the intake manifold 61 . 65 the intake manifold arrangement 60 ,

During engine operation, the intake manifold is created 61 . 65 a negative pressure, which causes air from the environment through the activated carbon of the filter 22 through the intake manifold 61 . 65 flows. The air desorbs on its way through the material of the filter 22 the accumulated hydrocarbons, so that they can be supplied to the engine combustion. The regeneration valve (TEV) 51 in the purge line arrangement 40 . 40 ' to the intake manifold 61 . 65 doses the regeneration stream or purge stream in air.

About the electrical duty cycle and the frequency of this Regenerierstrom the operating condition of the engine 10 be adjusted.

The registered amount of hydrocarbon material is treated with e.g. Using a lambda control inferred and the mixture adaptation, the injected via an injector amount of fuel is adjusted accordingly.

The intake manifold vacuum is not constant. The middle intake manifold vacuum depends on the operating point - e.g. the throttle position, the engine speed, etc. - from. Short term variations in intake manifold pressure are also caused by opening and closing the intake valves on the cylinders.

The stricter legal requirements for the tank ventilation system lead to an increasing demand for regeneration flows or purge streams in air. This can in a conventional tank ventilation system 1' according to 2 often can not be achieved or lead to increased fuel input from the tank vent in the fuel path.

Especially at idle - ie at maximum intake manifold vacuum - today's systems can lead to difficult to control mixture deviations.

To ensure a uniform distribution of the introduced fuel to the cylinders 12 to ensure the air and fuel flow from the tank ventilation according to the invention over a plurality Regenerierventile 51 , which are also referred to as tank ventilation valves, and in particular via at least one regeneration valve 51 per cylinder 12 the internal combustion engine 10 controlled supplied.

Furthermore, in conventional tank venting systems, the maximum amount of fuel supplied from the tank vent stream to the combustion is limited to a certain value for the sake of dynamics.

It is especially per cylinder 12 or per group 11 or bank of cylinders 12 should regeneration valves 51 installed as close to the inlet as possible in front of the inlet valve.

• – Reduzierte Laufunruhe und also gesteigerte Laufruhe des Motors 10 im Leerlauf,
• – Erhöhung der möglichen Spülmengen, vor allem im Leerlauf, weil keine Begrenzung auf Grund der Dynamik vorliegt,
• – Reduktion der Emissionen,
• – Reduktion des Kraftstoffverbrauches,
• – Ausweitung von Start/Stopp-Phasen und
• – Konzept zur Vermeidung von Drucktank oder Spülpumpe.

According to the invention, the following advantages occur, inter alia:

• - Reduced running noise and thus increased smoothness of the engine 10 idle,
• - Increasing the possible flushing volumes, especially at idle, because there is no limitation due to the dynamics,
• - reduction of emissions,
• - reduction of fuel consumption,
• - Extension of start / stop phases and
• - Concept for avoiding pressure tank or rinsing pump.

• – Besseres dynamisches Ansprechverhalten mit Reduktion der Lambdaabweichung liefert eine Optimierung der Emission,
• – Zylinderindividuelle Zumessung der Tankentlüftungsmenge,
• – Schnelle Reaktionszeit, z.B. Schubabschalten,
• – Verbesserung der Zumessgenauigkeit des Anteiles des Kraftstoffes aus der Tankentlüftung liefert eine Erhöhung des Kraftstoffanteils aus der Tankentlüftung in Bezug zu der über den Injektor zugeführten Menge, besonders bei Systemen mit CVO, mit CVO ist so ein kleinerer Wert Qmin des Injektors realisierbar,
• – in stationären Betriebspunkten, insbesondere im Leerlauf, ist eine Abschaltung des Injektors denkbar,
• – Erhöhung Drehzahlbereich saugsynchroner Tankentlüftung,
• – Verringerung Druckverlust mit Erhöhung der Spülmenge, besonders hilfreich bei VVT-Systemen,
• – Bei Systemen mit Zylinderabschaltung kann auf den nichtabgeschalteten Zylindern 12 weiterhin Tankentlüftung betrieben werden.

Due to the installation of a respective regeneration valve near the inlet valve following applications can be realized or improved:

• - Better dynamic response with reduction of lambda deviation provides optimization of emission,
• - cylinder-individual metering of the tank ventilation amount,
• - Fast reaction time, eg fuel cut-off,
• Improvement of the metering accuracy of the proportion of the fuel from the tank venting results in an increase of the fuel content from the tank vent in relation to the amount supplied via the injector, especially in systems with CVO, with CVO a smaller value Qmin of the injector can be realized.
• - In stationary operating points, in particular at idle, a shutdown of the injector is conceivable
• - Increasing the speed range of suction-synchronized tank ventilation,
• - Reduction of pressure loss with increased flushing volume, especially useful in VVT systems,
• - For systems with cylinder deactivation can on the non-shutdown cylinders 12 continue to operate tank ventilation.

Due to the higher purge volumes that can be achieved in this way, pressure tank or purge pump can be dispensed with if necessary.

In principle, applications with more TEVs than cylinders are conceivable.

Claims (11)

Tank ventilation system ( 1 ) for an internal combustion engine ( 10 ) of a vehicle ( 100 ), comprising: - a filter unit ( 20 ) for receiving and storing fuel vapors from a fuel tank ( 30 ) of the vehicle ( 100 ), - a purge line arrangement ( 40 ) for fluid-mechanical connection of the filter unit ( 20 ) with a suction line arrangement ( 60 ) of the internal combustion engine ( 10 ) of the vehicle ( 100 ) and - a regeneration valve unit ( 50 ) for controlling the fluid-mechanical connection of the filter unit ( 20 ) with the suction line arrangement ( 60 ) through the purge line arrangement ( 40 ), wherein the regeneration valve unit ( 50 ) a plurality of fluid-mechanically parallel-connected regeneration valves ( 51 ) having. Tank ventilation system ( 1 ) according to claim 1, wherein - the purge line arrangement ( 40 ) a purge line ( 41 ) with several sub-lines ( 42 ), - in each case a regeneration valve ( 51 ) in a sub-line ( 42 ) and - each sub-line ( 42 ) independent of other sub-lines ( 42 ) with the suction line arrangement ( 60 ) of the internal combustion engine ( 10 ) is fluid mechanically connected or connectable. Tank ventilation system ( 1 ) according to claim 1 or 2, wherein in the case of several groups ( 11 ) of cylinders ( 12 ) of the internal combustion engine ( 10 ) at least one regeneration valve ( 51 ) for each of the groups ( 11 ) of cylinders ( 12 ) is trained. Tank ventilation system ( 1 ) according to one of the preceding claims, in which in the case of several groups ( 11 ) of cylinders ( 12 ) of the internal combustion engine ( 10 ) each have several regeneration valves ( 51 ) for each of the groups ( 11 ) of cylinders ( 12 ) are formed, in particular in each case identical number. Tank ventilation system ( 1 ) according to one of the preceding claims, in which for each cylinder ( 12 ) of the internal combustion engine ( 10 ) at least one regeneration valve ( 51 ) is trained. Tank ventilation system ( 1 ) according to one of the preceding claims, in which for each cylinder ( 12 ) of the internal combustion engine ( 10 ) each have several regeneration valves ( 51 ) are formed, in particular with an identical number for each of the cylinders ( 12 ). Tank ventilation system ( 1 ) according to one of the preceding claims, in which a respective regeneration valve ( 51 ) upstream and adjacent to an inlet valve of a respective cylinder ( 12 ) is trained. Tank ventilation system ( 1 ) according to one of the preceding claims, in which for a cylinder ( 12 ) of the internal combustion engine ( 10 ) - a first regeneration valve ( 51 ) upstream and in the immediate vicinity of an inlet valve of the respective cylinder ( 12 ) is formed and - another regeneration valve ( 51 ) upstream and spaced to the inlet valve of the cylinder and the first regeneration valve ( 51 ) is trained. Tank ventilation system ( 1 ) according to one of the preceding claims, with a control unit ( 80 ), which are used to control the regeneration valve unit ( 50 ) and the regeneration valves ( 51 ) and thus the fluid-mechanical connection of the filter unit ( 20 ) with the suction line arrangement ( 60 ) through the purge line arrangement ( 40 ), in particular depending on an operating status of a drive system ( 90 ) of the vehicle ( 100 ), an operating status of the internal combustion engine ( 10 ) of the vehicle ( 100 ), a status of the filter unit ( 20 ) and / or environmental conditions. Drive system ( 90 ) for a vehicle ( 100 ), with: - an internal combustion engine ( 10 ) for driving a vehicle ( 100 ), - a fuel tank ( 30 ) for receiving fuel and for controllably supplying the internal combustion engine ( 10 ) with fuel and - a tank ventilation system ( 1 ) for the controllable fluid-mechanical connection between the fuel tank ( 30 ) and a suction line arrangement ( 60 ) of the internal combustion engine ( 10 ), in which a tank ventilation system ( 1 ) is designed according to one of claims 1 to 9. Vehicle ( 100 ), which with a drive system ( 90 ) is formed according to claim 10.

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