HoYoung Lee, TaeHee Cho, Chan-Hee Won, Byoungkee Kim
In CVT, it is essential to optimize Clamping Force in Pulley to improve fuel efficiency. Clamping force in pulley is shaft force to control primary pulley and secondary pulley. It is determined by pulley ratio, input engine torque in CVT and safety factor for protecting belt slip.It is difficult to calculate correct clamping force and detect belt slip. Generally speaking, CVT has a tendency to have excessive Safety factor to prevent belt slip. This excessive safety factor in clamping force leads to lower fuel efficiency. In order to find an optimal clamping force, ‘the minimum clamping force’ which will not induce belt slip should be determined even during decreasing a clamping force. Furthermore, clamping force should be maintained near the the ‘minimum clamping force’ For this, following logics were developed First, the logic to calculate first safety ratio of belt, Second the logic to detect belt slip state. Third, the logic to calculate the optimal clamping force. These logics were verified and validated on each SILS, HILS, Vehicle.