DEVICE FOR CONTROLLING BELT CLAMPING FORCE IN V-BELT CONTINUOUSLY VARIABLE TRANSMISSION

摘要

The case of braking slowly at first and then braking suddenly on a low µ road so that the brake stroke (STb) and the anticipated brake stroke (STb_(2)) change as illustrated is explained: after a start-of-braking determination time (t1) when the brake switch signal (SWb) switches from OFF to ON, a determination is made whether the braking is sudden or not by whether or not (STb_(2)) is at or above a sudden braking determination threshold (STb_s). During slow braking prior to the sudden braking determination time (t2) when (STb_(2))≥(STb_s), the slow braking inertial torque (Tj) is set to be smaller in the period (t1)-(t2) than the inertial torque during sudden braking after (t2) as shown by the solid line. The belt clamping force is controlled based on the primary input torque during slow braking, which is obtained by subtracting (Tj) from the transmission input torque. As a result, the increase in belt clamping force during slow braking is reduced as compared to during sudden braking by the area indicated by the hatching, making it possible to prevent the increase from becoming excessive.