Mazda Motor Corporation

Kiyotaka Sato

Ryohei Ono

Kenji Uchida

Noriyuki Ota

Hidefumi Fujimoto

Takeshi Nagasawa

Masahisa Yamakawa

Keiji Araki

Toshiaki Nishimoto

Tatsuya Fujikawa

Kouji Shishime

Disclosed herein is a fuel injection control device for a direct injection engine including an engine body (engine) and a fuel injection control unit (engine controller). The fuel injection control unit injects a fuel in a predetermined injection mode into a combustion chamber () such that while the engine body is warm, an air-fuel mixture layer and a heat-insulating gas layer, surrounding the air-fuel mixture layer, are formed in the combustion chamber at a point in time when an air-fuel mixture ignites, and changes the injection mode of the fuel into the combustion chamber such that while the engine body is cold, the lower the temperature of the engine body is, the thinner the heat-insulating gas layer becomes.

Fuel injection control device for direct injection engine

A fuel injection valve () is configured such that the effective opening area of an injection port () increases as its lift amount increases. A fuel injection control unit (an engine control unit) injects fuel in a lift amount changing mode wherein, when fuel is injected into a combustion chamber () in the terminal period of the compression stroke, the lift amount of the fuel injection valve is set to a predetermined large lift amount in the earlier period of the injection period, and in the later period of the injection period following the earlier period of the injection period, the lift amount is set to a small lift amount smaller than the large lift amount and is in a range where the fuel injection speed increases.

Fuel injection control device for direct-injection engine

A multi-hole injector directly injects fuel into a combustion chamber. Intake air is introduced into the combustion chamber through intake ports to provide tumble flow in the combustion chamber. A cavity is formed in a part of the top surface of a piston which is eccentric to the exhaust side. In the intake stroke, fuel injection ends in a downstroke of a piston. When the crank angle is 100 degrees after the top dead center in the intake stroke at which the fuel injection ends, a most downward lower spray collides with a part of the top surface of the piston which ranges on the intake side from the edge on the exhaust side of the cavity. A most upward upper spray does not come into contact with a spark plug. Thus, the fuel injection can enhance the tumble flow to promote homogeneous dispersion of fuel-air mixture in the combustion chamber.

Internal combustion engine of spark-ignition direct-injection type and fuel injecting method thereof

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Yokohama, Japan

Kiyotaka Sato