초록 ▼

A method for improving efficiency and reducing emissions of an internal combustion engine. Variable displacement engine capabilities are achieved by disabling engine valves during load changes and constant load operations. Active cylinders may be operated at minimum BSFC by intermittently disabling

A method for improving efficiency and reducing emissions of an internal combustion engine. Variable displacement engine capabilities are achieved by disabling engine valves during load changes and constant load operations. Active cylinders may be operated at minimum BSFC by intermittently disabling other cylinders to provide the desired net torque. Disabling is begun by early closing of the intake valve to provide a vacuum at BDC which will result in no net gas flow across the piston rings, and minimum loss of compression energy in the disabled cylinder; this saving in engine friction losses is significant with multiple disablements.

대표청구항 ▼

[ Based on the forgoing description of the invention, what is claimed is:] [1.] A method for operating a vehicle internal combustion engine system which has a controller with a computer having a memory containing engine characteristics, and sensor means for receiving input signals from engine and ve

[ Based on the forgoing description of the invention, what is claimed is:] [1.] A method for operating a vehicle internal combustion engine system which has a controller with a computer having a memory containing engine characteristics, and sensor means for receiving input signals from engine and vehicle components, and with output means to deliver signals to engine controls; at least two of said input signals being the position of an accelerator pedal and engine speed, and at least three of said output signals being those which control engine intake valves, exhaust valves, and fuel injectors; the method comprising steps of:a) computing said engine torque requirement at said engine speed,b) looking up in said memory torques at said engine speed which have minimum brake specific fuel consumption,c) determining a cylinder disablement strategy versus time which will provide said torque requirement at said minimum brake specific fuel consumption,d) controlling said engine system by said method.