BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an engine system construction diagram showing an engine controller according to a first embodiment of the invention;
FIG. 2 exemplifies lift curve characteristics of variable inlet and outlet valves for the engine controller in FIG. 1;
FIG. 3 exemplifies a fuel injection control technique for the engine controller in FIG. 1, in which FIG. 3A shows relation ship between an opening-closing operation of the variable inlet valve and outlet valve in each cylinder and plural fuel injection timings (multiple injection times), and FIG. 3B shows relationship between the first fuel injection quantity and the compression ignition timing;
FIG. 4 exemplifies injection characteristics when an injector for the engine controller in FIG. 1 degrades;
FIG. 5 is a control flowchart for the engine controller in FIG. 1;
FIG. 6 shows compression-ignited combustion range when a small degree of deterioration is detected in the injector for the engine controller in FIG. 1;
FIG. 7 shows compression-ignited combustion range when a large degree of deterioration is detected in the injector for the engine controller in FIG. 1;
FIG. 8 is an engine system construction diagram showing an engine controller according to a second embodiment of the invention;
FIG. 9 is a control flowchart for the engine controller in FIG. 8;
FIG. 10 shows compression-ignited combustion states of a high load area when deterioration is detected in the injector of the engine controller in FIG. 8 and fuel injection control and variable valve control are provided, in which FIG. 10A shows a combustion state for a new injector, FIG. 10B shows a combustion state for a degraded injector, FIG. 10C shows a case of changing only a fuel injection quantity in the state of FIG. 10B, and FIG. 10D shows a case where the fuel injection quantity and the valve timing are changed in the state of FIG. 10B in accordance with the flowchart in FIG. 9 to resolve unstable combustion in FIG. 10B and a knocking phenomenon in FIG. 10C; and
FIG. 11 shows compression-ignited combustion states of a low load area when deterioration is detected in the injector of the engine controller in FIG. 8 and fuel injection control and variable valve control are provided, in which FIG. 11A shows a combustion state for a new injector, FIG. 10B shows a combustion state for a degraded injector, FIG. 11C shows a case of changing only a fuel injection quantity in the state of FIG. 11B, and FIG. 11D shows a case where the fuel injection quantity and the valve timing are changed in the state of FIG. 11B in accordance with the flowchart in FIG. 9 to resolve unstable combustion in FIG. 11B and inefficient combustion in FIG. 11C.
Patent Application
20070215096
