Power plants – Internal combustion engine with treatment or handling of... – Methods
Patent
1996-03-21
1998-09-15
Wolfe, Willis R.
Power plants
Internal combustion engine with treatment or handling of...
Methods
60283, 60286, 60300, 12333919, 123518, F01N 320, F01N 336, F02D 3300, F02M 3302
Patent
active
058063048
DESCRIPTION:
BRIEF SUMMARY
This invention relates to internal combustion engines and the management of the catalytic treatment of the exhaust gas from such engines.
In a majority of the developed countries of the world, there exist regulations regarding the release of a wide range of pollutants from motor vehicles into the atmosphere. One of the principal sources of such pollutants is the exhaust gas from the engine of the vehicle wherein the level of undesirable pollutants therein is largely dependent upon the level of control achievable over the combustion process within the respective cylinders or combustion chambers of the engine and any after-treatment of the exhaust gas by means such as catalytic converters or the like.
Another source of pollutant from motor vehicles is the vapour generated in the fuel tank thereof which may contain a substantial level of hydrocarbons. In this connection, it is known that in operating a vehicle, the fuel tank can reach a temperature of the order of 55.degree. C. or more. Accordingly, there is a significant level of vapour generated in the fuel tank which may be harmful if released in an untreated or uncontrolled manner to atmosphere. Currently, most regulations relating to the control of pollutants or emissions arising from fuel vapour generated by a vehicle require the fuel tank of the vehicle to be sealed when the vehicle is in operation. Consequently, it is necessary to provide a suitable form of venting of the fuel tank including a separator wherein vapour released from the fuel tank is processed to remove any fuel vapour from the air component thereof before the latter is released to atmosphere. Usually, the separator is of the known activated carbon type commonly referred to in the automotive industry as a "carbon canister".
It is known in some prior art systems such as fuel injected, homogeneous charge, four stroke engines to provide an air flow through the carbon canister when the engine is in operation so that fuel collected in the canister as a result of the vapour in the fuel tank may be delivered into the air induction system of the engine to then pass into the engine combustion chambers and be burnt therein before being exhausted from the engine by way of an exhaust system thereof. It will be appreciated that the purging of the carbon canister in this way will provide an additional supply of fuel to the engine which would, unless counteracted, cause it to run rich or even misfire if the rich misfire limit of the particular engine is exceeded.
In homogeneous charge, four stroke engines, this additional supply of fuel to the engine will typically be sensed by the overall air/fuel ratio management system and more particularly by an exhaust gas oxygen sensor or "Lambda" sensor thereof and a corrective action in respect of the fuelling rate will typically be made. Such systems are commonly referred to as "closed loop" systems since the correct air/fuel ratio is maintained through a feed-back loop. Thus, when the carbon canister is being purged as described above and thereby providing additional fuel to the engine, this action will be counteracted by a reduction of the fuelling rate by the engines fuelling system (eg: fuel injectors) as dictated by the Lambda sensor.
However, the above described system for purging the carbon canister is not suitable for use in lean-burn engines, which normally operate under an "open-loop" system and do not utilise a Lambda sensor during lean-burn operation, since it is difficult to compensate for the additional fuel being supplied to the engine during the canister purging process.
There has previously been proposed in the applicant's granted Australian Patent No. 641223 a method to communicate the carbon canister with a compressor so that the intake air to the compressor is passed through the canister to take up fuel therein. The fuel taken up by the air is subsequently delivered to the engine combustion chambers with the compressed air used during the fuel injection process. This proposal has the advantage that the purged fuel from the carbon canister
REFERENCES:
patent: 4993225 (1991-02-01), Giacomazzi et al.
patent: 5207058 (1993-05-01), Sasaki et al.
patent: 5209061 (1993-05-01), Takeshima
patent: 5239824 (1993-08-01), Matsumoto
patent: 5245974 (1993-09-01), Watson et al.
patent: 5272873 (1993-12-01), Hamazaki
patent: 5353590 (1994-10-01), Pettit et al.
patent: 5417059 (1995-05-01), Hartel et al.
patent: 5544483 (1996-08-01), Heuer
patent: 5617721 (1997-04-01), Slawson
International Publication No. WO 91/13521 published Sep. 5, 1991.
Patent Abstract No. 3-242415 Oct. 1991 Japan.
Patent Abstract No. 62-251415 Nov. 1987 Japan.
Patent Abstract No. 59-58143 Apr. 1984 Japan.
Price Stuart Graham
Worth David Richard
Orbital Engine Company (Australia) Pty. Limited
Wolfe Willis R.
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