Patent attributes
A startup assistance device, which assists startup of an internal combustion engine in which fuel is supplied from an electronically controlled fuel injection device and ignition is performed by an ignition device, includes a recoil starter which is driven by manpower and which performs cranking for starting up the internal combustion engine, an electric rotary machine which adds torque to a crankshaft of the internal combustion engine during at least one of a startup period of the internal combustion engine using the recoil starter and a standby period before the startup period, a power source unit which supplies power to the electric rotary machine, and a control unit which controls the magnitude and time of the torque output by the electric rotary machine.