Torque detection device of rear frame for electrically assisted bicycle

Abstract

A torque detection device of a rear frame of an electrically assisted bicycle includes two displacement detection units and a processing unit. The displacement detection units are installed at upper and lower fork arms of the rear frame respectively for detecting and converting displacement into force. Through mechanical analysis and mathematical operations, the processing unit processes signals obtained by the displacement detection units to remove any force perpendicular to a road surface and obtain a rider's treading torque while pedaling a pedal crank module. The displacement detection units are mounted onto the upper and lower fork arms without requiring any rotary joint. The displacement detection units are displacement detection devices applying different physical and chemical methods, such as strain gauges, piezoelectric sensors, electromagnetic sensors, capacitive sensors, or optical sensors. The torque detection device features simple manufacture and device, and the advantage of measuring the treading torque accurately.