Exhaust gas recirculation system
AssigneeMazda Motor Corporation
InventorsKenji Kashiyama, Kazumasa Nomura, Noriyuki Iwata, Naoyuki Yamagata
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Abstract
An exhaust gas recirculation system of an engine equipped with a supercharger has an exhaust gas circulation passage for circulating exhaust gas into an intake system from an exhaust system, and a return passage for returning exhaust gas introduced into the exhaust gas circulation passage to the exhaust system. The exhaust gas circulation passage is made available to the exhaust gas when the engine operates within a specified area of engine operating conditions in which supercharging is to be effected. The return passage is made available to the exhaust gas when the engine operates within an area, other than the specified area, of engine operating conditions.
Claims12
An exhaust gas recirculation system of an internal combustion engine, having an intake system for introducing fresh air into the internal combustion engine and an exhaust system for discharging exhaust gas produced in the internal combustion engine therethrough, said exhaust gas recirculation system comprising:
- an exhaust gas circulation passage, interposed between said intake system and said exhaust system, for circulating exhaust gas into said intake system from said exhaust system;
- filtering means, disposed in said exhaust gas circulation passage, for filtering exhaust gas passing therethrough;
- cooling means, disposed in said exhaust gas circulation passage between said filtering means and said exhaust system, for cooling exhaust gas passing therethrough;
- and
- a blowby gas passage, connected between the internal combustion engine and said exhaust gas circulation passage at a position between said filtering means and said cooling means, for introducing blowby gas produced in the internal combustion engine into said exhaust gas circulation passage therethrough.
An exhaust gas recirculation system of an internal combustion engine, having an intake system for introducing fresh air into the internal combustion engine, said intake system including a supercharger, and an exhaust system for discharging exhaust gas produced in the internal combustion engine therethrough, said exhaust gas recirculation system recirculating exhaust gas into intake air and comprising:
- an exhaust gas circulation passage, interconnected to both the intake system before a location at which the supercharger is disposed and the exhaust system, for circulating exhaust gas into said intake system from said exhaust system;
- a return passage, disposed between said exhaust gas circulation passage and the exhaust system after a location at which said exhaust gas circulation passage branches off, for returning exhaust gas introduced into said exhaust gas circulation passage into the exhaust system therethrough;
- valve means, disposed in said exhaust gas circulation passage, for selectively rendering said exhaust gas circulation passage and said return passage available to exhaust gas introduced from the exhaust system;
- detecting means, provided in cooperation with the internal combustion engine, for detecting engine operating conditions;
- and
- control means for controlling said valve means to render said exhaust gas circulation passage available to said exhaust gas when said detecting means detects an engine operating condition falling within a specified area of engine operating conditions in which supercharging is to be effected and said return passage available to said exhaust gas when said detecting means detects an engine operating condition falling within a remaining area of engine operating conditions other than said specified area.
Dependencies are inferred from the claim text.