Method and device for controlling the pressure inside a fuel tank

A technology of internal pressure and fuel tank, applied in power plant, layout, transportation and packaging combined with internal combustion engine fuel supply, etc., can solve problems such as unfavorable activated carbon filter uniform adsorption and separation of fuel, etc.

CN102555786AActive Publication Date: 2012-07-11AUDI AG
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2012-07-11

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Abstract

The invention relates to a method for controlling the pressure inside a fuel tank of an internal combustion engine of a motor vehicle includes relieving the pressure in the fuel tank when reaching a predetermined upper overpressure threshold value. In a device for controlling the pressure in the fuel tank, the pressure in the fuel tank is only relived partially, wherein the pressure relief is less than 20%, preferably less than 10% and optimally less than 5% of the upper overpressure threshold value in order to reduce the emission of volatile hydrocarbons into the environment.
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Description

technical field

[0001] The invention relates to a method and a device for controlling the internal pressure of a fuel tank of an engine of a motor vehicle according to the preambles of claims 1 , 2 , 9 and 10 . Background technique

[0002] Especially in newer passenger cars with closed fuel tanks, which are usually blow-molded from a plastic material which may contain at least one layer of metal foil to reduce the permeability of the fuel tank . However, the plastic material used to make fuel tanks usually begins to yield when the temperature is above 50°C. In this case, when there is an overpressure or negative pressure in the fuel tank that exceeds the allowable pressure range, the fuel tank may first be damaged. Irreversibly deformed, wherein said permissible overpressure is typically about 380 mbar, and the permissible underpressure is typically about 150 mbar.

[0003] In addition, new passenger vehicles are equipped with a device for ventilating and ventilating the ...

Examples

Embodiment Construction

[0025] The fuel tank 1 for a motor vehicle shown in the drawings is a sealed fuel tank 1 made of an airtight and liquid-tight interlayer material by blow molding. For filling, the fuel tank 1 has a filler pipe 3 which can be closed by a fuel tank cap 2 . Near the bottom 4 of the fuel tank 1 there is a supply unit 5 with a fuel pump 6 immersed in the fuel.

[0026] The fuel tank 1 is equipped with a ventilation and ventilation device, by means of which the pressure inside the fuel tank 1 can also be controlled. Ventilation and ventilation unit including activated carbon filter 7, fuel tank shut-off valve 8, two fuel tank pressure regulator valves 9 and 10, liquid trap 11, fuel tank pressure sensor 12 and multiple rollover safety valves 13, 14, 15 . The liquid trap 11 arranged in the gas space or the head space of the fuel tank 1 adjacent to the upper side of the fuel tank 1 shall prevent the mixed gas flowing from the inside of the fuel tank 1 when the fuel tank 1 is ventilat...