Engine exhaust emission control system
AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorsYoshiaki Danno, Kazuo Koga, Takashi Dougahara
Life of this patent
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Abstract
An engine exhaust emission control system, in which a valve is set at a hydrocarbon adsorbing position to guide exhaust emissions to a bypass line including an adsorbent sieve for adsorbing hydrocarbons during a initial period of engine start-up, and the valve is switched over to a hydrocarbon purging position to guide exhaust emissions to an exhaust line and to divert a part of the exhaust emissions to the bypass line.
Claims18
An engine exhaust emission control system comprising:
- an exhaust line;
- a catalytic converter positioned in the exhaust line for receiving exhaust emissions from an engine;
- a bypass line extending from the exhaust line at a position upstream of the catalytic converter;
- an adsorbent sieve adsorptive of hydrocarbons from exhaust emissions and positioned in the bypass line;
- a valve disposed in the exhaust emission line, the valve being selectively operated to a hydrocarbon adsorbing position to direct exhaust emissions to the adsorbent sieve via the bypass line, or to a hydrocarbon purging position to direct exhaust emissions to the catalytic converter via the exhaust line and to divert a part of exhaust emissions to the adsorbent sieve via the bypass;
- and
- a control means for setting the valve to the hydrocarbon adsorbing position during an initial period of engine start-up, and to the hydrocarbon purging position after the completion of engine start-up.
An engine exhaust emission control system comprising:
- an exhaust line;
- a bypass line branching from the exhaust line;
- a first catalytic converter disposed in the exhaust line at a position upstream of the bypass line;
- a second catalytic converter disposed in the exhaust line downstream of a position where the end of the bypass line merges into the exhaust line;
- an adsorbent sieve adsorptive of hydrocarbons in exhaust emissions and positioned in the exhaust bypass line;
- a valve disposed in the exhaust emission line, the valve being selectively operated to a hydrocarbon adsorbing position to direct exhaust emissions to the adsorbent sieve via the bypass line, or to a hydrocarbon purging position to direct exhaust emissions to the catalytic converter via the exhaust line and to divert a part of exhaust emissions to the adsorbent sieve via the bypass line;
- and
- a control means for setting the valve to the hydrocarbon adsorbing position during an initial period of engine start-up, and to the hydrocarbon purging position after the completion of engine start-up.
An engine exhaust emission control system comprising:
- an exhaust line;
- a catalytic converter positioned in the exhaust line for receiving exhaust emissions from an engine;
- a bypass line branching from the exhaust emission line at a position downstream of the catalytic converter;
- an adsorbent sieve adsorptive of hydrocarbons in exhaust emissions and positioned in the bypass line;
- a valve disposed in the exhaust line, the valve being selectively operated to a hydrocarbon adsorbing position to direct exhaust emissions to the adsorbent sieve via the exhaust bypass line, or to a hydrocarbon purging position to direct exhaust emissions away from the catalytic converter via the exhaust line and to divert a part of exhaust emissions to the adsorbent sieve via the bypass line;
- a recycle line extending between the adsorbent sieve and the exhaust line upstream of the catalytic converter;
- and
- a control means for setting the valve to the hydrocarbon adsorbing position during an initial period of engine start-up, and to the hydrocarbon purging position after the completion of engine start-up.
An exhaust emission control system comprising:
- an exhaust line;
- a catalytic converter in said exhaust line for receiving exhaust emissions from an engine;
- an additional line communicating with said exhaust line for receiving exhaust from an engine;
- an adsorbent sieve adsorptive of hydrocarbons from exhaust emissions in said additional line;
- a two-position valve selectively operated to a first position to direct all exhaust emissions from an engine to said adsorptive sieve and said catalytic converter or to a second position to direct a portion of the exhaust emissions to said adsorptive sieve and all exhaust emissions to said exhaust line;
- and
- means for setting said valve in said first or said second position.
An engine exhaust emission control system comprising:
- a catalytic converter for receiving exhaust emissions from an engine;
- an adsorptive sieve adsorptive of hydrocarbons from exhaust emissions for receiving exhaust emissions from an engine;
- a two-position valve selectively operated to a first position which directs all exhaust from an engine to said catalytic converter and said adsorptive sieve or to a second position which directs a portion of the exhaust emissions from an engine to said adsorptive sieve and all emissions to said catalytic converter;
- and
- means for setting said valve in said first or said second position.
Dependencies are inferred from the claim text.