Filter device for ventilation device of fuel tank of vehicle

Abstract

The invention relates to a filter device (10) for a ventilation device of a fuel tank (100) of a vehicle. The filter device has a filter housing (20) with a filter chamber (22); the filtering chamber is filled with an adsorbing material (30); the adsorbing material is used for at least partially adsorbing fuel vapor; the filter housing has a tank interface (24) for fluid communication with the fuel tank, an engine interface (26) for fluid communication with an internal combustion engine (200) of the vehicle, and a ventilation interface (28) for fluid communication with the environment; a buffer wall (40) is further arranged in the filter chamber between the tank interface and the engine interface (26) for preventing fuel vapor from overflowing to the engine interface (26) from the tank interface (24). The buffer wall (40) has at least one bore section (42) with a through-bore (44) with a flow-rate-dependent flow resistance against the flow of fuel vapor therethrough.

Description

technical field [0001] The invention relates to a filter device for a ventilation system of a fuel tank of a vehicle and to a buffer wall for such a filter device. Background technique [0002] It is well known that the fuel tank of a vehicle must have ventilation. This is generally used to avoid negative pressure in the fuel tank when fuel is being removed from the internal combustion engine. Likewise, when the tank is filled with new fuel through the filling nozzle or when an overpressure in the tank occurs due to thermal expansion at high external temperatures, the overpressure in the tank must be balanced. In the event of overpressure, it must be possible to escape gas from the fuel tank. This is usually released into the environment through the ventilation openings of the ventilation device. In this case, however, it must be ensured that excessive escape of fuel vapors via the ventilation device is avoided. Thus, in known fuel tanks, these ventilation means are equi...

AI Technical Summary

Problems solved by technology

However, the application of a negative pressure entails the risk that, in addition to or instead of the tank connection, saturated fuel vapors are re-breathed directly into the engine connection via a shorter path without bypassing the filter device

During the operation of this engine, this leads to the fact that regeneration can only be performed for a very short period, because otherwise the regeneration gases flowing into the internal combustion engine via the engine connection could have a negative composition that could adversely affect the combustion process

However, the use of a so-called buffer wall in the area of ​​the filter housing has the disadvantage that although this bypass prevents a direct overflow from the tank connection into the engine connection, the same section within the filter device cannot Regeneration via the buffer wall

The filter must therefore be designed correspondingly larger, since it cannot be completely restored to the regenerated state

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