Patent ID: 7079941

Claim:
An engine starting system for automatically stopping an engine which comprises: a fuel injection controller for controlling the quantity of fuel to be injected by each of fuel injectors directly into a plurality of cylinders and fuel injection timing thereof; an ignition controller for controlling ignition timing of spark plugs of the individual cylinders; an intake air quantity regulator for regulating the quantity of intake air introduced into each of the cylinders; an alternator driven by the engine; and a rotating speed sensing device for detecting engine speed; said engine starting system comprising: an automatic engine stop controller for automatically stopping the engine by interrupting fuel injection from the fuel injectors as necessary for keeping the engine running when predefined automatic engine stop conditions are satisfied, and an automatic engine restart controller for automatically restarting the engine by causing the fuel injector of at least one of the cylinders which is on expansion stroke at engine stop and causing the spark plug of that cylinder to ignite a mixture produced therein when predefined engine restart conditions are satisfied; wherein said automatic engine stop controller sets the quantity of intake air regulated by said intake air quantity regulator at a level higher than a minimum quantity of intake air necessary for keeping the engine running by a specific amount and sets a scavenging mode period for expelling in-cylinder exhaust gas by decreasing the amount of electric power generated by said alternator prior to fulfillment of the automatic engine stop conditions in an early part of automatic engine stop control operation, said automatic engine stop controller causes said intake air quantity regulator to decrease the quantity of intake air and causes said alternator to once decrease the amount of electric power generated thereby at a point in time when the engine speed drops down to a predetermined reference engine speed, and said automatic engine stop controller causes said alternator to increases the amount of electric power generated thereby after a lapse of a specific period of time.