Exhaust gas purifying device for internal combustion engine
AssigneeNissan Motor Co., Ltd.
InventorsYoshiki Sekiya, Tetsuya Kamihara, Eiji Aiyoshizawa
Life of this patent
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Abstract
An exhaust gas purifying device which is provided with catalytic converter and a fuel injector which are disposed upstream of a particulate matter trap. The fuel injection injects fuel to the catalytic converter to rise exhaust gas temperature by its oxidation reaction heat when the exhaust gas temperature is slightly lower than a predetermined regeneration temperature. Further, a closable bypass passage is communicated with the passage between the catalytic converter and the trap and functions to allow to bypass exhaust gases in accordance with the trap condition and the exhaust gas temperature.
Claims8
An exhaust gas purifying system for an internal combustion engine, comprising:
- a catalytic converter disposed in an exhaust conduit of an internal combustion engine;
- means for supplying fuel to an upstream side of said catalytic converter, said fuel supply means taking one of an operative state and an inoperative state;
- a trap disposed in the exhaust conduit downstream of said catalytic converter to trap particulate matter contained in exhaust gas;
- means defining a bypass passage whose upstream end is communicated with the exhaust conduit between said catalytic converter and said trap and whose downstream end is communicated with the exhaust conduit downstream of said trap;
- a bypass valve disposed in said bypass passage and operative to take one of a closing state to close the bypass passage and an opening state to open the bypass passage;
- means for detecting an exhaust gas temperature in the exhaust conduit between said catalytic converter and said trap;
- means for controlling fuel supply of said fuel supply means and operation of said bypass valve in accordance with the exhaust gas temperature detected by said gas temperature detecting means.
An exhaust gas purifying system for an internal combustion engine, comprising:
- a catalytic converter disposed in an exhaust conduit of an internal combustion engine;
- means for supplying fuel to an upstream side of said catalytic converter, said fuel supply means taking one of an operative state and an inoperative state;
- a trap disposed in the exhaust conduit downstream of said catalytic converter to trap particulate matter contained in exhaust gas;
- means defining a bypass passage whose upstream end is communicated with the exhaust conduit between said catalytic converter and said trap and whose downstream end is communicated with the exhaust conduit downstream of said trap;
- a bypass valve disposed in said bypass passage and operative to take one of a closing state to close the bypass passage and an opening state to open the bypass passage;
- means for detecting an exhaust gas temperature in the exhaust conduit between said catalytic converter and said trap;
- means for controlling fuel supply of said fuel supply means and operation of said bypass valve in accordance with the exhaust gas temperature detected by said gas temperature detecting means, said control means taking one of a first control state to put said fuel supply means into said operative state and to put said bypass valve into the closing state when the exhaust gas temperature is in a predetermined temperature range which is lower than a regeneration temperature, a second control state to put said fuel supply means into said inoperative state and to put said bypass valve into the closing state when the exhaust gas temperature is higher than the predetermined temperature range, and a third control state to put said fuel supply means into said inoperative state and to put said bypass valve into the opening state when the exhaust gas temperature is lower than the predetermined temperature range.
Dependencies are inferred from the claim text.