Control device and method for a diesel engine and diesel engine
AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorsKei Shigahara, Michihiro Hata, Toshinori Morita, Noriyuki Koga, Yuji Yanagawa
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Abstract
A low NOx combustion mode is executed in which the fuel injected timing IT is greatly advanced to 36° BTDC as compared with a normal value of roughly 10° BTDC. At this fuel injection timing IT, the smoke emission amount is suppressed below an extremely low value, even if the EGR ratio Regr is increased to about 56%, and the NOx emission amount is suppressed owing to a large amount of EGR, so that the smoke and NOx can be reduced at the same time.
Claims17
A control device for a diesel engine comprising:
- a fuel injection part for injecting a fuel into a combustion chamber of an engine;
- an EGR ratio adjusting part for adjusting a recirculation amount of exhaust gas exhausted from the engine into an intake air system;
- and
- a controller for controlling the operation of the fuel injection part and the EGR ratio adjusting part,
- wherein the controller sets up a fuel injection timing of the fuel injection part at an advance side from an injection timing when a smoke emission characteristic indicates a decreasing tendency after indicating an increasing tendency in accordance with an increase in EGR ratio, and at a lag side from an injection timing when the injected fuel gets out of a cavity formed in a piston and gets to a cylinder wall face, and the controller executes a first control mode for controlling the operation of the EGR ratio adjusting part to reduce a smoke emission amount and a NOx emission amount from the engine.
A control method for a diesel engine comprising:
- injecting a fuel into a combustion chamber of an engine by a fuel injection part;
- and
- adjusting a recirculation amount of exhaust gas exhausted from the engine into an intake air system by a EGR ratio adjusting part;
- wherein a fuel injection timing of the fuel injection part is set up at an advance side from an injection timing when a smoke emission characteristic indicates a decreasing tendency after indicating an increasing tendency in accordance with an increase in EGR ratio, and at a lag side from an injection timing when the injected fuel gets out of a cavity formed in a piston and gets to a cylinder wall face, and the operation of the EGR ratio adjusting part is controlled to reduce a smoke emission amount and a NOx emission amount from the engine.
A diesel engine comprising:
- a combustion chamber defined by a cylinder wall face;
- a piston having a cavity;
- a fuel injection part for injecting a fuel into the combustion chamber;
- an intake air system;
- an EGR ratio adjusting part for adjusting a recirculation amount of exhaust gas exhausted from the engine into the intake air system;
- and
- a controller for controlling the operation of the fuel injection part and the EGR ratio adjusting part,
- wherein the controller sets up a fuel injection timing of the fuel injection part at an advance side from an injection timing when a smoke emission characteristic indicates a decreasing tendency after indicating an increasing tendency in accordance with an increase in EGR ratio, and at a lag side from an injection timing when the injected fuel gets out of the cavity and gets to the cylinder wall face, and the controller executes a first control mode for controlling the operation of the EGR ratio adjusting part to reduce a smoke emission amount and a NOx emission amount from the engine.
Dependencies are inferred from the claim text.