Patent ID: 8566007

Claim:
An automatic stop/restart device for an internal combustion engine, for automatically stopping the internal combustion engine when a predetermined automatic stop requirement is satisfied during an operation of the internal combustion engine and for restarting the internal combustion engine when a predetermined restart requirement is satisfied while the internal combustion engine is in an automatically stopped state, comprising: a rotation-speed computation means for computing a rotation speed of the internal combustion engine; a starter including a pinion gear to be brought into meshing engagement with a ring gear connected to a crankshaft of the internal combustion engine to rotationally drive the ring gear, a pinion-gear push-out device for bringing the pinion gear into the meshing engagement with the ring gear, a starter motor for rotationally driving the pinion gear, and a starter-motor driving device for driving the starter motor; and a restart control means (a) for allowing the pinion-gear push-out device to push out the pinion gear, after elapse of a driving waiting time for the starter motor, which is computed based on a plurality of characteristics obtained in advance, (b) for allowing the starter-motor driving device to drive the starter motor, and (c) for restarting fuel supply from a fuel injection valve to a combustion chamber of the internal combustion engine, when the rotation speed of the internal combustion engine at time of satisfaction of the predetermined restart requirement, the rotation speed being computed by the rotation-speed computation means, is lower than a lower limit rotation speed, wherein the lower limit rotation speed is a speed at which the starter can be operated in order of the driving of the starter motor and the pushing of the pinion gear, and the predetermined restart requirement is satisfied while the internal combustion engine is rotating by inertia after being automatically stopped, wherein the driving waiting time computation includes a rotation speed of the internal combustion engine obtained after a meshing-engagement completion time, which is determined from the rotation speed of the internal combustion engine at a restart request.