Turbocharged diesel engine
AssigneeNissan Motor Co., Ltd.
InventorShuji Kimura
Life of this patent
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Abstract
In a diesel engine in which boost air is supplied by a turbocharger, the generation of dry soot, which is a component of smoke, is suppressed by lowering the intake air temperature in the cylinder at the compression top dead center position of the piston. The fuel injected into the intake air is ignited by the heat of this compression. In order to reduce the intake air temperature at the top dead center position without reducing the amount of the intake air, the boost pressure of the turbocharger is lowered and also the effective compression ratio by the piston for the intake air is raised by, for example, altering the closing timing of an intake valve.
Claims7
A diesel engine, comprising:
- a cylinder;
- a turbocharger which supplies intake air to said cylinder at a boost pressure;
- a piston which compresses intake air in said cylinder with an effective compression ratio by reciprocating between a bottom dead center position and a top dead center position thereof, fuel supplied to said cylinder being ignited by the heat of compression of said compressed intake air;
- means for calculating a compressed intake air temperature in said cylinder at said top dead center position;
- means for lowering said boost pressure of said turbocharger, when said compressed intake air temperature has exceeded a predetermined temperature;
- and
- means for increasing said effective compression ratio, when said compressed intake air temperature has exceeded said predetermined temperature.
Dependencies are inferred from the claim text.