| 摘要 |
PROBLEM TO BE SOLVED: To reduce NOx causing the problem in compression stroke injection, and to improve significant torque in intake stroke injection. SOLUTION: In this cylinder direct injection type internal combustion engine, at high load time, fuel injection is performed in the intake stroke, and at medium load time, fuel injection is performed in the compression stroke. The engine includes a variable valve system for continuously variable-controlling the opening and closing timing of an intake valve, so that in the compression stroke injection, the intake value opening timing IVO is made earlier, and the closing timing IVC is made later. Thus, exhaust emission remains much in the cylinder to reduce NOx. In the intake stroke injection, the intake value opening timing IVO is made later, and the closing timing IVC is made earlier. Thus, discharge return of air-fuel mixture is decreased to enhance filling efficiency, so that torque is improved. COPYRIGHT: (C)2004,JPO
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