Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
  • F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
  • F02M25/0854—Details of the absorption canister

Definitions

• the invention relates to activated carbon filters for motor vehicles for the adsorption of fuel vapors formed in the tank and possibly in the float chamber of the carburetor of motor vehicles and for the desorption and return of the vapors into the combustion chambers of the motor of the motor vehicle, consisting of a in a receiving space with a packing Enclosed housing made of activated carbon of suitable pore size and closed on all sides with a tank inlet that can be connected to a connecting line leading to the motor vehicle tank or the carburettor float chamber, and a connecting line that can be connected to a suction pipe or air filter housing of the engine.
• activated carbon filters are arranged at least in the vent line of the tank of passenger cars, which adsorb the fuel vapors displaced in the activated carbon bed when the motor vehicle is refueled or when the fuel in the tank is expanded due to heating via the tank vent and thus prevent their escape into the ambient atmosphere at least as long as the adsorbability of the activated carbon bed is not exhausted.
• Adequate measurement of the amount of activated carbon and regular desorption of the fuel vapors and their return to the combustion circuit of the engine can ensure that under normal operating conditions of the motor vehicle no fuel vapors escape into the ambient atmosphere.
• the desorption takes place in such a way that ambient or fresh air is sucked through the activated carbon bed and the fuel vapors are detached, ie desorbed, from the surface of the activated carbon.
• the vacuum generated in the engine intake manifold when the engine is running is used.
• activated carbon filters for the application in question here have three connections, namely an inlet connected to a connecting line to the motor vehicle tank through which the fuel vapors enter the housing
• Ambient atmosphere open inlet and outlet through which on the one hand the air freed from the fuel vapors can escape to the ambient atmosphere and on the other hand outside air can be sucked in through the activated carbon bed during the desorption process, and finally one to one of the suction pipe or the air filter of the internal combustion engine leading line connected outlet through which the desorbed fuel vapors are fed into the intake system of the engine and then burned in the engine.
• a ventilation valve or a Flushing valve arranged, which are controlled according to the operating conditions.
• the normally closed purge valve is only opened when the engine is running, so that ambient air can be drawn in through the fresh air inlet due to the negative pressure that then arises in the housing of the activated carbon filter and the fuel vapors adsorbed in the activated carbon bed can be desorbed. If, on the other hand, the vent / ventilation valve in the connecting line to the active carbon housing is opened due to the development of an increased vapor pressure in the tank, the fuel vapors which pass into the active carbon housing, together with the fresh air drawn in, are immediately passed on to the running engine and burned. The fuel vapors enter the activated carbon bed only when the engine is stopped and the purge valve is closed and are prevented from escaping into the surrounding atmosphere in the desired manner. So far the system of adsorption of
• Fuel vapors known by activated carbon filters are particularly useful and are known from DE-GM 92 10 525.
• Another possibility of introducing water into the activated carbon bed is that, together with the gasified fuel displaced from the tank, water vapor contained in the air also condenses when, for example, the ambient temperature drops, so that water from this fuel-air mixture then condenses and gets into the active carbon bed. Since the tank connection is generally provided on the upper side of the housing of the activated carbon filter, this condensed water is therefore introduced into the activated carbon filter from above and thus drips onto the upper side of the activated carbon bed and soaks it in one of the amount of the condensing water vapor dependent dimensions.
• the invention is based on the object of preventing the effectiveness of the activated carbon filter from deteriorating with regard to the adsorption and desorption capacity of fuel vapors as a result of moisture penetration of the activated carbon bed.
• this object is achieved according to the invention in that the venting or fresh air stream loaded with water, water droplets or water vapor is guided into a water collecting trough arranged in the flow direction in front of the activated carbon receiving space in the housing their top has a connection to the Ak ivkohle-A f fortuneraum, and that a floatable valve body is arranged in the sump, which floats on water collecting in the sump and closes the connection to the activated carbon-receiving space or one of the activated carbon-Avem Spotifyra m immediate drain to the ambient atmosphere opens.
• the water penetrating into the activated carbon filter housing is thus collected in the collecting trough. occurs in the activated carbon bed by either closing the floating valve body itself from the connection to the activated carbon receiving space or emptying the collecting pan to the outside in good time before it overflows due to the rising level of the condensing water collected.
• the fresh air inlet is usually provided on the bottom or bottom side of the activated carbon filter housing and does not open directly into the activated carbon receiving space, but rather a condensate space underneath, which is pressed against the bed of coal by elastic pre-tensioning is completed.
• Fresh air inlet flows out, the passage is opened again after a short time and fresh air can flow through the Activated carbon bed sucked and used for desorption of the fuel vapors.
• the floatable valve body in the collecting space is guided in the vertical direction in such a way that it is aligned with the passage.
• the collecting trough is formed with a cylindrical circumferential wall and projecting from the circumferential wall of the valve body facing the peripheral wall of the valve body are guide ribs which center the valve body in the collecting trough and thus align it with the passage in the partition.
• the valve body expediently has a conical delimiting surface which interacts with the passage, which is delimited in the form of a circular cross section, as the valve surface.
• the penetration of water condensing from the tank (or the carburetor-float chamber) and air vapor saturated with fuel vapor into the activated carbon bed is prevented by the fact that the collecting trough inside the housing is below the - generally at the top of the Ge ⁇ provided - tank inlet is arranged so that the air loaded with the fuel vapors from the fuel tank first flows into the collecting pan and is then deflected in order to be led to the engine outlet via the collecting pan which is open at the top.
• a drainage opening is then expediently provided in the bottom of the collecting trough, to which a line connected through the activated carbon receiving space to a condensate space provided under the activated carbon bed and connected via the fresh air inlet to the outlet atmosphere is connected, the floatable line Valve body then on its underside in alignment with the drain opening and the drain opening in a non-floating state State of tightly sealing valve projection welded on.
• the condensate water that collects in the collecting pan thus automatically opens a drain to the outside atmosphere when the water level rises so far that the valve body floats up.
• valve projection is expediently guided in alignment with guide ribs protruding from the bottom of the collecting trough to the drain opening, wherein a further additional guidance of the valve body by ribs protruding from the inside of the housing is also possible.
• FIG. 1 shows a first embodiment of an activated carbon filter according to the invention, the side of which is partially broken open at the top and cut in the broken area, the valve body arranged in the lower broken area in a collecting pan in which the passage of Air-permitting lowered position is shown;
• FIG. 2 shows the lower broken area of the activated carbon filter shown in FIG. 1 in the state in which the floating valve body closes the connection of the fresh air inlet to the activated carbon receiving space of the housing;
• 3 shows a representation corresponding to the representation according to FIG. 1 of an activated carbon filter which is slightly modified compared to the exemplary embodiment of the activated carbon filter shown in FIGS. 1 and 2;
• FIGS. 1 and 3 show a representation, corresponding again to FIGS. 1 and 3, of a third exemplary embodiment of an activated carbon filter according to the invention, in which, however, precaution against moisture penetration of the activated carbon bed by condensate water supplied via the tank inlet. he is hit.
• the activated carbon filter shown in FIG. 1, designated in its entirety by 10, has a housing 12 made of plastic which is closed on all sides and which consists of the actual basic housing, which in the case shown is cylindrical and closed on the underside by an end wall 14 16 exists, the other, open end face of which is closed by a separate end cover 18, which after the assembly of the activated carbon filter - for example by hot mirror welding - is inseparably connected to the basic housing 16.
• a separate end cover 18 which after the assembly of the activated carbon filter - for example by hot mirror welding - is inseparably connected to the basic housing 16.
• In the middle of the lower end wall 14 of the housing 12 there is an inlet connection 20, which is thus connected to the ambient atmosphere.
• the inlet connector 20 thus has the function of a fresh air inlet.
• the front cover 18, which closes the basic housing 16 on the upper end face, has two connections, namely a tank inlet 22 which can be connected to a connecting line to the fuel tank and one to one for the intake pipe or air filter housing of the associated engine Motor vehicle leading connecting line connectable motor outlet 24th
• a bed 26 of activated carbon particles of suitable pore size is provided in the central cylindrical region of the basic housing 16, and is suitably held under prestress between two vapor or gas-permeable cover plates 28 and 30, so that the activated carbon particles also when shaken or under the influence of acceleration forces cannot shift relative to one another and can grind in this way.
• the space of the housing formed between the cover plates 28 and 30 can thus also be referred to as an activated carbon receiving space.
• the lower cover plate 28 is held at a distance above the mouth of the fresh air inlet 20 on a circumferential shoulder 34 of the basic housing 16 and is provided with a large number of through openings (not shown), the size of which is selected to be smaller than the particle size of the activated carbon bed.
• the upper cover plate 30 can, for example, be a sieve plate with larger passage openings, under which a fleece filter (not shown) can additionally be provided, which prevents the passage of even the finest activated carbon dust particles to the tank inlet 22 or the motor outlet 24 .
• the upper cover plate 30 can be prestressed in the downward direction by a tension spring (not shown).
• a line 36 is connected through the cover plate 30, the activated carbon bed 26 and the cover plate 28, which leads as an overflow or condensate space 38 formed under the cover plate 28. That with the engine of the vehicle running over the Engine outlet 24 from the fuel tank and the mixture of air and fuel vapors is thus sucked through the activated carbon bed 26, the fuel vapors being adsorbed. Any condensing water vapor contained in the mixture of air and fuel vapors, on the other hand, is eliminated during the deflection in the overflow or condensate space and can exit via the fresh air inlet 20.
• recessed collecting pan 40 is formed with a substantially cylindrical peripheral wall and a flat bottom, in which the fresh air inlet 20 opens in the middle.
• the collecting trough 40 is sealed off from the overflow or condensate space 38 by a partition wall 42, but fresh air sucked in via a central passage 44 in the partition wall 42 through the fresh air inlet into the interior of the housing 12 of the activated carbon filter 10 can kick. Water vapor condensed in the overflow or condensate space 38 can also flow out through the passage 44 into the collecting trough 40 and then through the fresh air inlet 20.
• a valve body 46 is arranged such that it can float vertically, guided by ribs 48 on the peripheral wall of the collecting trough 40, which in the lowered position shown in FIG. 1 rests on projections 50 on the bottom of the collecting trough, so that the valve body 46 neither the fresh air inlet 20 nor the passage 44 closes.
• the valve closes the Passage 44 facing conical boundary surface of the valve body 46 the passage 44, so that no water can then pass from the collecting trough 40 into the overflow or condensate space 38.
• the embodiment of the activated carbon filter 10 shown in FIG. 3 differs only slightly from the activated carbon filter 10 shown in FIGS. 1 and 2 in that the line 36 connected inside the housing 12 to the tank inlet 22 in the case of the embodiment according to FIGS 1 and 2 laterally offset to the longitudinal center axis of the housing and in the case of the activated carbon filter 10 according to FIG. 3, the housing passes through the center, ie that the longitudinal central axis of the housing 12 and the line 36 coincide. Otherwise they correspond to the design of both activated carbon filters largely identically, so that a more detailed description to avoid repetition is omitted, especially since the same reference numerals are assigned to the same parts of the two activated carbon filters 10.
• the activated carbon filter 110 shown in FIG. 4 has a fundamentally similar structure to the previously described activated carbon filter 10, and components that functionally match each other are also provided with the same reference symbols in the different exemplary embodiments, with only one "1" in the case of the activated carbon filter 110. is placed in front. It is therefore sufficient in the following to emphasize the differences compared to the activated carbon filters 10, while for the basic structure, the previous description of the activated carbon filter 10 can be referenced.
• the motor inlet 122 opens into the space formed above the activated carbon bed 126 in the housing and does not - as one might think at a glance at the drawing - lead into the overflow or condensate space 138 is, but opens directly into the space formed in the front cover 118.
• the opening of the motor outlet 124 does not open into the space formed in the end cover 118, but is connected to a line 136 which, in a manner not shown, through the cover plate 130, the activated carbon bed 126 and the cover plate 128 in the FIGS Condensate or overflow space 138 is guided.
• Fresh air sucked in via the fresh air inlet 120 during the journey is thus sucked directly into the overflow or condensate space 138 into the mouth of the line 136 ending there, so that the risk of water droplets entrained in the fresh air from below into the activated carbon bed 126 penetration is relatively low, especially if the mixture of air and fuel vapors also flows in the opposite direction through the activated carbon bed 126.
• the formation of a collecting trough corresponding to the collecting trough 40 in the end wall 14 is therefore largely unnecessary and is not realized in the exemplary embodiment shown, although it could basically be provided in the same way as in the previously described exemplary embodiments.
• a collecting trough 140 is formed in the end cover 118 below the tank inlet 122 in the activated carbon filter 110, which has a drain opening 144 in its bottom, at which a line led through the cover plate 130, the activated carbon bed 126 and the cover plate 128 142 is connected, which thus opens into the overflow or condensate space 138.
• a floatable valve body 146 is guided to float in the vertical direction, which is provided on its underside with a valve projection 150 that is aligned with the drain opening 144 and seals it tightly in the non-floating state.
• the floatable valve body 146 is guided through ribs 148, which rise from the bottom of the collecting trough 140 and the valve projection 150 between them.
• ribs 152 projecting downward from the inside of the end cover 118 and leading to the actual valve body 146 can also be provided in order to ensure that the valve body is also in exact alignment with the drain opening 144 when vibrations are transmitted from the vehicle to the activated carbon filter is led.
• the water which condenses into water droplets from the mixture of air and fuel vapors precipitates in the collecting tank and thereby slowly fills the collecting tank 140.
• the valve projection 150 opens the drain opening 144 and the water collected in the collecting trough 140 can be passed via the line 142 to the overflow or condensate chamber 138 flow from where it then exits the fresh air inlet 120 or - if the entry speed of the fresh air into the inlet 120 is relatively strong due to a relatively high negative pressure generated by the engine, initially collects in the overflow or condensate space 138 and possibly also to Part is sucked into the line 136 with the sucked-in fresh air and led to the engine outlet.
• the activated carbon bed 126 is not wetted under any circumstances, so that the desired goal of preventing the activated carbon bed from becoming wet is also achieved in this case.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Filtering Materials (AREA)
• Supplying Secondary Fuel Or The Like To Fuel, Air Or Fuel-Air Mixtures (AREA)
• Carbon And Carbon Compounds (AREA)
• Separation Of Gases By Adsorption (AREA)
• Water Treatment By Sorption (AREA)
• Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6898053

Family Applications (1)

Country Status (8)

Cited By (3)

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Citations (7)

Family Cites Families (4)

• 1993
  • 1993-09-13 DE DE9313840U patent/DE9313840U1/de not_active Expired - Lifetime
• 1994
  • 1994-08-06 AT AT94926159T patent/ATE159323T1/de not_active IP Right Cessation
  • 1994-08-06 HU HU9600400A patent/HU218772B/hu not_active IP Right Cessation
  • 1994-08-06 PL PL94313169A patent/PL173945B1/pl unknown
  • 1994-08-06 EP EP94926159A patent/EP0719384B1/de not_active Expired - Lifetime
  • 1994-08-06 DE DE59404367T patent/DE59404367D1/de not_active Expired - Fee Related
  • 1994-08-06 WO PCT/EP1994/002615 patent/WO1995008059A1/de active IP Right Grant
  • 1994-08-06 ES ES94926159T patent/ES2109727T3/es not_active Expired - Lifetime
  • 1994-08-06 CZ CZ96750A patent/CZ284270B6/cs not_active IP Right Cessation

Patent Citations (7)

Non-Patent Citations (2)

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