Tank venting device for a fuel tank, and vehicle

Abstract

A tank venting device for a fuel tank that supplies an internal combustion engine with a fuel includes a fuel vapor sorption system that is configured for reversibly storing fuel vapor in, and removing it from, the fuel tank, wherein the tank venting device includes at least one purge device, which is operable independently of the internal combustion engine, for applying a motive flow to the fuel vapor sorption system in the direction opposite from the fuel tank, so that the fuel vapor sorption system can be purged via a purge line, wherein the purge device includes at least one control device for controlling the motive flow.

Claims

1. A tank venting device for a fuel tank that supplies an internal combustion engine with a fuel, the tank venting device comprising: a fuel vapor sorption system that is configured for reversibly storing fuel vapor in, and removing it from, the fuel tank, and at least one purge device, which is operable independently of the internal combustion engine, for applying a motive flow to the fuel vapor sorption system in the direction opposite from the fuel tank, so that the fuel vapor sorption system can be purged via a purge line, wherein the purge device includes at least one control device including at least one control valve for regulating the motive flow through the purge line, wherein the control valve is a volume control valve configured to enable quantitative regulation of the motive flow through the purge line, wherein the fuel vapor sorption system includes at least one tank vent valve situated downstream from a sorption agent container and upstream from the purge device relative to the applied motive flow, wherein the purge device includes at least one purge air pump; a first partial purge line and a second partial purge line, parallel to the first partial purge line, are downstream from the at least one tank vent valve, wherein the at least one purge air pump and the at least one control valve are situated in the first partial purge line; and wherein the at least one control valve is situated downstream from the purge air pump, relative to the applied motive flow.

2. The tank venting device according to claim 1, wherein the purge air pump is electrically and/or mechanically operable.

3. The tank venting device according to claim 1, wherein the fuel vapor sorption system further comprises a diagnostic module connected to the sorption agent container via two lines, wherein the diagnostic module includes a pump.

4. The tank venting device according to claim 1, wherein a check valve is situated in the second partial purge line.

5. The tank venting device according to claim 1, wherein the at least one control valve does not include a check valve.

6. A vehicle comprising: an internal combustion engine that is operable with a fuel; a fuel tank that is designed to supply the internal combustion engine with fuel; and a tank venting device comprising: a fuel vapor sorption system that is configured for reversibly storing fuel vapor in, and removing it from, the fuel tank; and at least one purge device, which is operable independently of the internal combustion engine, for applying a motive flow to the fuel vapor sorption system in the direction opposite from the fuel tank, so that the fuel vapor sorption system can be purged via a purge line; wherein the purge device includes at least one control device including at least one control valve for regulating the motive flow through the purge line, and the fuel vapor sorption system includes at least one tank vent valve situated downstream from a sorption agent container, wherein the purge device includes at least one purge air pump; a first partial purge line and a second partial purge line, parallel to the first partial purge line, are downstream from the at least one tank vent valve; wherein the at least one purge air pump and the at least one control valve are situated in the first partial purge line; and wherein the at least one control valve is situated downstream from the purge air pump, relative to the applied motive flow.

7. The vehicle according to claim 6, wherein the fuel vapor sorption system further comprises a diagnostic module connected to the sorption agent container via two lines, wherein the diagnostic module includes a pump.

8. The vehicle according to claim 6, further comprising a check valve situated in the second partial purge line.

9. The vehicle according to claim 6, wherein the at least one control valve does not include a check valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained below in exemplary embodiments with reference to the associated drawings, which show the following:

(2) FIG. 1 shows a block diagram of a vehicle with a tank venting device according to the invention;

(3) FIG. 2 shows another block diagram of a vehicle with a tank venting device according to one alternative embodiment of the invention; and

(4) FIG. 3 shows another block diagram of a vehicle with a tank venting device according to one alternative embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a block diagram of a vehicle 1 having a tank venting device 2 according to the invention. FIG. 1 thus shows a vehicle, denoted overall by reference numeral 1, in which the presented tank venting device 2 is correspondingly accommodated. The vehicle 1 includes an internal combustion engine 10, an air supply system 20, an exhaust gas system 30, and a fuel vapor sorption system 40. Although a fuel supply system is not explicitly illustrated, it is understood that such a system is provided.

(6) The internal combustion engine 10 includes at least one, in the present case four, for example, cylinders 11, and may be a (self-ignition) diesel engine or a (spark ignition) gasoline engine. In the present example, the engine is a gasoline engine in which ignition takes place by means of spark plugs.

(7) The internal combustion engine 10 is operable with a fuel 50, in the present case gasoline. The fuel 50 is stored in a fuel tank 60 that may be filled via a filler neck 65, and that is equipped with a level sensor 66 for detecting the filling level. The fuel 50 is supplied to the internal combustion engine 10 via a fuel supply system, not shown in greater detail.

(8) The combustion air 21 is supplied to the engine 10 by the air supply system 20, which draws in the air 21 from the surroundings and feeds it into the engine 10 via an intake line 22 and an air manifold 23, which distributes the air 21 to the cylinders 11. In the illustrated example, the combustion air 21 is compressed by a compressor 25 of an exhaust gas turbocharger 26 in order for the engine 10 to be operable at an increased charge pressure and thus with higher power. The compressor 25 is driven by a turbine 35, via a shaft, situated in the exhaust gas system 30. Situated in the intake line 22, downstream from the compressor 25, is an adjustable throttle valve 36 by means of which the cylinder charging is controllable or regulatable.

(9) An exhaust gas of the internal combustion engine 10 is discharged via the exhaust gas system 30, and optionally undergoes catalytic aftertreatment. For this purpose, the exhaust gas system 30 includes an exhaust manifold 31 which collects the exhaust gases from the cylinders 11 of the engine 10 and conducts them into a shared exhaust duct 32. The above-mentioned turbine 35 of the exhaust gas turbocharger 26 is situated in the exhaust duct 32, so that the exhaust gas drives the turbine 35, and thus the compressor 25, with withdrawal of kinetic energy. The turbine 35 may be bypassed by means of a turbine bypass 33, wherein the portion of the exhaust gas that is led through the turbine bypass 33 is adjustable via an actuating means 70 that is situated in the turbine bypass 33 and that may be, for example, a wastegate or in general, an electrically actuated valve.

(10) The fuel vapor sorption system 40 has a sorption agent container 41 in which a sorption agent 42 for sorption of fuel vapors, i.e., hydrocarbons, is present. In the present case, sorption is understood to mean any reversible binding, for example absorption, physical adsorption (physisorption), and/or chemical adsorption (chemisorption). The sorption agent 42 is preferably activated carbon, in particular an activated carbon filter, that binds fuel vapors by physical adsorption. In this regard, the sorption agent container 41 may also be referred to as an activated carbon container. The sorption agent container 41 is connected to the fuel tank 60 via a fuel vapor line 43. A purge line 44 branches off from the sorption agent container 41 and is divided into a first partial purge line 441 and a second partial purge line 442.

(11) A purge device 37 is situated in the partial purge line 441. In addition, a control device 39 associated with the purge device is illustrated in front of the purge device 37 and in the present example, downstream from the purge device 37; in the present case the control device is illustrated as a control valve. The purge device 37 also includes a purge air pump 38.

(12) The first partial purge line 441 opens into the intake line 22 via the suction side of the purge device 37. Downstream from the throttle valve 36, the second partial purge line 442 opens into the intake line 22 or directly into the air manifold 23. A tank vent valve 80 for adjusting, in particular limiting, the volume flow in the purge line 44 is situated in the shared section of the purge line 44. For example, the tank vent valve 80 may be designed as a valve that is controllable via an electric motor. A blocking means 90 that is designed to allow flow only in the direction of the intake line 22 or the air manifold 23 is situated in the partial purge line 442. If the downstream pressure at the blocking means 90 is greater than the upstream pressure or is greater than a predetermined pressure, the blocking means 90 automatically closes. The blocking means 90 in this case is illustrated as a check valve. The fuel vapor sorption system 40 also includes a diagnostic module 100 that is in fluid-conducting connection with the sorption agent container 41 via two lines. The diagnostic module 100 has an overpressure valve that is connected to the surroundings, and a pump (neither of which is illustrated). The diagnostic module 100 is used on the one hand for pressure compensation of the sorption agent container 41 and the fuel tank 60, and on the other hand for monitoring tank leaks.

(13) In summary, the tank venting device 2 thus includes the following components: a fuel vapor sorption system 40 that is configured to reversibly store fuel vapor [in, and remove it] from, the fuel tank 60, a purge device 37, which is operable independently of the internal combustion engine 10, for applying a motive flow to the fuel vapor sorption system 40 in the direction opposite from the fuel tank 60, so that the fuel vapor sorption system 40 can be purged via a purge line 44, wherein the purge device 37 includes a control device 39 for controlling the motive flow, and includes a purge air pump 38.

(14) FIG. 2 shows another block diagram of a vehicle 1 according to one alternative embodiment of the invention. The illustrated components and their positioning are essentially identical to the design shown in FIG. 1. Only the positioning of the tank vent valve 80 is illustrated differently.

(15) In FIG. 2, the tank vent valve 80 instead of a blocking means is provided in the second partial purge line 442. In other words, the tank vent valve 80 is provided directly upstream from an inlet of the partial purge line 442 into the intake line 22. The introduction point is thus situated directly downstream from the tank vent valve 80, so that an additional check valve at this location is no longer necessary.

(16) FIG. 3 shows another block diagram of a vehicle 1 according to one alternative embodiment of the invention. The illustrated components and their positioning are essentially identical to the design shown in FIG. 1. Only the positioning of the tank vent valve 80 is illustrated differently.

(17) In FIG. 3, the tank vent valve 80 instead of a blocking means is provided in the second partial purge line 442. In other words, the tank vent valve 80 is provided directly upstream from an inlet of the partial purge line 442 into the intake line 22. The introduction point is thus situated directly downstream from the tank vent valve 80, so that an additional check valve at this location is no longer necessary.

(18) The air supply system 20 also has a return line 101 that branches off from the intake line 22 downstream from the compressor 25 and once again opens into the intake line 22 upstream from the compressor 25. A Venturi nozzle 102 is situated in the return line 101. In addition, a control device 39 is situated in front of the Venturi nozzle 102 and in the present example, downstream from the Venturi nozzle 102; in the present case, the control device is illustrated as a control valve. In addition, a blocking means 91 is provided between the Venturi nozzle 102 and the control device 39, and directly behind the Venturi nozzle 102. The blocking means 91 in this case is illustrated as a check valve. Parallel to the return line 101, a second return line 103 is apparent, which directly behind the blocking means 91 is combined with the return line 101, so that the control device 39 also acts on this return line 103. A purge device 37 is apparent in the return line 103. The purge device 37 includes an illustrated purge air pump 38 and a control device 39, which in this case is illustrated as a control valve. In addition, a further blocking means 92 is situated downstream from and directly behind the purge air pump 38, this blocking means 92 also being illustrated as a check valve.

(19) In all FIGS. 1 through 3 shown, in addition to the description, directional arrows are illustrated at the appropriate locations which clarify the flow direction and the terms “upstream” and “downstream.”

LIST OF REFERENCE NUMERALS

(20) 1 vehicle 2 tank venting device 10 internal combustion engine 11 cylinder 20 air supply system 21 combustion air 22 intake line 23 air manifold 25 compressor 26 exhaust gas turbocharger 30 exhaust gas system 31 exhaust manifold 32 exhaust duct 33 turbine bypass 35 turbine 36 throttle valve 37 purge device 38 purge air pump 39 control device 40 fuel vapor sorption system 41 sorption agent container 42 sorption agent 43 fuel vapor line 44 purge line 50 fuel 60 fuel tank 65 filler neck 66 level sensor 70 actuating means 80 tank vent valve 90 blocking means 91 blocking means 92 blocking means 100 diagnostic module 101 return line 102 Venturi nozzle 103 return line 441 first partial purge line 442 second partial purge line