| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently ensure a negative pressure necessary for operating a brake booster in accordance with an operating degree of a brake, in an internal combustion engine formed by providing the brake booster. SOLUTION: In an inner wall surface peripheral part of a cylinder head 4 in the vicinity of a first/second intake valve 6a, 6b of an engine 1, a fuel injection valve 11 is arranged, fuel therefrom is injected directly in a cylinder 1a. Relating to an intake duct 20 in the downstream from an electronically controlled throttle valve 23, a brake booster 71 for ensuring brake force of a vehicle is provided. In an electronic control unit (ECU)30, in the case of a relative pressure in the brake booster smaller than a reference value, closing control of the throttle valve 23 is executed. Regardless of whether the pressure is smaller than the reference value or not, in the case that a decreasing degree of the relative pressure in the brake booster is larger than a prescribed amount, the throttle valve 23 is controlled so as to rapidly close it, a negative pressure is forcedly generated. |
