| 摘要 |
PROBLEM TO BE SOLVED: To provide an intake control unit which reduces pumping loss in an intake stroke and which suppresses counterflow of exhaust gas to an intake passage so as to prevent aggravation of combustion, thereby improving fuel consumption. SOLUTION: In the intake control unit 4 of an internal combustion engine 1, an intake control valve 40 performs the first opening/closing operation in which it operates from a fully closed state (1) to a fully opened state (2) after the overlap period of an inlet valve, and an exhaust valve has passed in one cycle of the internal combustion engine. Then the valve operates from a fully opened state (3) to a fully closed state (4) prior to closure of the inlet valve after completion of required intake operation. The intake valve 40 performs the second opening/closing operation in which it operates from a fully closed state (5) to a fully opened state (6) again after the inlet valve has been closed, so that the pressure in the intake passage (a dead volume portion D) is made equal to the atmospheric pressure, and then it operates from a fully opened state (7) to a fully closed state (8) again prior to opening of the inlet valve. COPYRIGHT: (C)2003,JPO |
