Patent ID: 7140990

Claim:
A belt drive continuously-variable transmission control apparatus comprising: a belt drive continuously-variable transmission unit including a primary pulley adapted to be connected with an engine through a torque converter, and a secondary pulley connected with the primary pulley by a V belt; a shift control valve to control a fluid pressure to the primary pulley; a shift control section to control an actual transmission ratio of the continuously-variable transmission unit by controlling the shift control valve; a line pressure control section to control a line pressure to be supplied to the shift control valve and the secondary pulley, in accordance with an estimated input torque to the continuously-variable transmission unit; and an input torque estimating section to determine the estimated input torque in accordance with a speed ratio and a torque ratio of the torque converter, the input torque estimating section including; a speed ratio monitoring subsection to examine whether the speed ratio is in an increasing state; and a torque ratio setting subsection to decrease the torque ratio when the speed ratio is in the increasing state so that the torque ratio at a given value of the speed ratio becomes smaller when the speed ratio is in the increasing state than when the speed ratio is in a decreasing state.