초록 ▼

An exhaust passage (2) of a diesel engine (1) is connected to an intake passage (3) via an exhaust gas recirculation passage (4) provided with an exhaust gas recirculation valve (6). A turbine (52) of a variable capacity turbocharger (50) is provided in the exhaust passage (2). The controller (41) c

An exhaust passage (2) of a diesel engine (1) is connected to an intake passage (3) via an exhaust gas recirculation passage (4) provided with an exhaust gas recirculation valve (6). A turbine (52) of a variable capacity turbocharger (50) is provided in the exhaust passage (2). The controller (41) controls the opening of the exhaust gas recirculation valve (6), and the opening of a nozzle (53) of the turbine (52). A controller (41) first calculates a target exhaust gas recirculation valve opening surface area based on a target exhaust gas recirculation flowrate, and controls the exhaust gas recirculation valve opening to the target exhaust gas recirculation valve opening surface area.

대표청구항 ▼

[ What is claimed is:] [1.]1. A control device for controlling an opening of an exhaust recirculation valve which is provided in an exhaust gas recirculation passage of an diesel engine and an opening of a turbine nozzle which is provided in a turbine of a turbocharger of the diesel engine, the dies

[ What is claimed is:] [1.]1. A control device for controlling an opening of an exhaust recirculation valve which is provided in an exhaust gas recirculation passage of an diesel engine and an opening of a turbine nozzle which is provided in a turbine of a turbocharger of the diesel engine, the diesel engine being provided with an intake passage and an exhaust passage, the exhaust gas recirculation passage connecting the intake passage and the exhaust passage, the turbine being disposed in the exhaust passage and driving a compressor disposed in the intake passage, the control device comprising:a sensor which detects an engine rotation speed; anda microprocessor programmed to:calculate a target exhaust gas recirculation flowrate based on a target exhaust gas recirculation rate;calculate a target exhaust gas recirculation valve opening surface area based on the target exhaust gas recirculation flowrate;control the opening of the exhaust gas recirculation valve to the target exhaust gas recirculation valve opening surface area;calculate a target turbocharging pressure;calculate an exhaust system total opening surface area from the target turbocharging pressure and the engine rotation speed;calculate an opening surface area of the turbine nozzle when the same flowrate of exhaust gas as the target exhaust gas recirculation flowrate flows through the turbine, as an exhaust gas recirculation valve opening surface area equivalent value;calculate a nozzle opening surface area equivalent value by deducting the exhaust gas recirculation valve opening surface area equivalent value from the exhaust system total opening surface area;calculate a target nozzle opening surface area based on the nozzle opening surface area equivalent value; andcontrol the opening of the turbine nozzle to the target nozzle opening surface area.