초록 ▼

An internal combustion engine having a direct cylinder injection and including a variable valve timing mechanism for at least changing the time of closing of the intake valve. The fuel injection timing and intake valve closing timing are controlled so that under low and mid-range engine speeds, but

An internal combustion engine having a direct cylinder injection and including a variable valve timing mechanism for at least changing the time of closing of the intake valve. The fuel injection timing and intake valve closing timing are controlled so that under low and mid-range engine speeds, but high loads, the intake valve is closed before the piston reaches bottom dead center position on its intake stroke so as to reduce the effective compression ratio. Fuel injection timing is begun before the piston has reached its bottom dead center position during the intake stroke under high-speed, high-load conditions and is not initiated until after the piston has reached its bottom dead center position and begun its compression stroke under other engine running conditions. The engine is provided with an injector location and piston with a bowl in its head that improves fuel stratification under at least some running conditions so as to permit lean burn operation. The intake valves are offset to one side of a plane containing the axis of the cylinder bore, and the fuel injector is disposed between a pair of intake ports and below them so as to direct its injection axis toward the exhaust side and toward the recess in the head of the piston.

대표청구항 ▼

[ What is claimed is:] [1.] A direct cylinder fuel injected engine comprised of a cylinder block defining a cylinder bore, a piston reciprocating in said cylinder bore, a cylinder head assembly affixed to said cylinder block and closing one end of said cylinder bore, said cylinder head, said piston,

[ What is claimed is:] [1.] A direct cylinder fuel injected engine comprised of a cylinder block defining a cylinder bore, a piston reciprocating in said cylinder bore, a cylinder head assembly affixed to said cylinder block and closing one end of said cylinder bore, said cylinder head, said piston, and said cylinder bore forming a variable volume chamber, intake passage means terminating at at least one intake port communicating with said variable volume chamber for delivering an intake charge thereto, exhaust passage means extending from at least one exhaust port for discharging combustion products from said combustion chamber, a poppet type intake valve cooperating with said intake port for controlling the flow therethrough, a poppet type exhaust valve for cooperating with said exhaust port for controlling the flow therethrough, means for operating said intake and exhaust valves in timed sequence with the rotation of the output shaft of said engine and including means for varying at least the time of closing of said intake valve relative to the position of said piston within said cylinder bore, a fuel injector for injecting fuel into said variable volume chamber, and control means responsive to engine speed and engine load for controlling the timing of closing of said intake valve so that said intake valve closes before the piston reaches bottom dead center position on its intake stroke when said engine is operating at a high load in low and medium speed ranges and for effecting the closing of the intake valve after the piston has reached its bottom dead center position and is moving upwardly on the compression stroke under other engine running conditions.