초록 ▼

An engine has variable timing mechanisms, which are controlled in starting an engine to set valve opening overlap of an intake valve and an exhaust valve around 30° CA. In this case, internal EGR is actively conducted and fuel burning velocity within a cylinder becomes relatively slow and unburned f

An engine has variable timing mechanisms, which are controlled in starting an engine to set valve opening overlap of an intake valve and an exhaust valve around 30° CA. In this case, internal EGR is actively conducted and fuel burning velocity within a cylinder becomes relatively slow and unburned fuel within the cylinder is emitted to an exhaust pipe to be post-burned by itself. Temperature of exhaust gas is maintained high and catalyst converters in the cold state may be activated quickly by actively implementing the post-burning within the exhaust pipe. Further, ignition timing is retarded, an air-fuel ratio is controlled at a slightly lean ratio and the exhaust valve is advanced. The effect of raising the temperature of exhaust gas by the post-burning may be realized more reliably by combining each of these controls.

대표청구항 ▼

An engine has variable timing mechanisms, which are controlled in starting an engine to set valve opening overlap of an intake valve and an exhaust valve around 30° CA. In this case, internal EGR is actively conducted and fuel burning velocity within a cylinder becomes relatively slow and unburned f

An engine has variable timing mechanisms, which are controlled in starting an engine to set valve opening overlap of an intake valve and an exhaust valve around 30° CA. In this case, internal EGR is actively conducted and fuel burning velocity within a cylinder becomes relatively slow and unburned fuel within the cylinder is emitted to an exhaust pipe to be post-burned by itself. Temperature of exhaust gas is maintained high and catalyst converters in the cold state may be activated quickly by actively implementing the post-burning within the exhaust pipe. Further, ignition timing is retarded, an air-fuel ratio is controlled at a slightly lean ratio and the exhaust valve is advanced. The effect of raising the temperature of exhaust gas by the post-burning may be realized more reliably by combining each of these controls.