The present invention relates to an electric power assist device for bicycles, which enables proper power assist control in response to a pedaling force without any complicated feature for detecting pedaling force and any necessary modification to the bicycle. An electric power assist device for bicycles of the present invention comprises: a dynamic brake circuit (inverter 126) which is connected to an electric motor 58 for generating an assist force; a rotational angle sensor 134 configured to detect a crank rotational angle of a crankshaft 24; a current sensor 140 configured to detect a value of motor current supplied to the electric motor 58; a dynamic brake controller 160 configured to stop supply of current from a battery 122 to the electric motor 58 and bring the dynamic brake circuit to an ON state when the crank rotational angle is within one or more predetermined crank rotational angle ranges; a pedaling force estimator 154 configured to estimate a pedaling force put on each pedal of a bicycle 10 based on a value of reverse current caused by a counter electromotive force and detected by the current sensor 140 when the dynamic brake circuit is in the ON state; and a motor drive controller 164 configured to control the electric motor 58 based on the pedaling force estimated by the pedaling force estimator 154.
POWER ASSIST DEVICE FOR BICYCLES, AND BICYCLE
2022-07-07
Patent
Electronic Resource
English
IPC: | B62M RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES , Antrieb von Radfahrzeugen oder Schlitten durch den Fahrer |