Patent ID: 7039516
Filing Date: 2006-05-02
Classification: F16H,Y10T

Abstract:
1. A belt type continuously variable transmission, comprising: a primary pulley on an input side having a groove which varies according to an oil pressure; a secondary pulley on an output side having a groove which varies according to an oil pressure; a belt wound around the primary pulley and secondary pulley; detecting means for detecting a vehicle running state; pulley ratio setting means for setting a final pulley ratio achieved by a shift of the pulley ratio of the primary and secondary pulleys, based on the vehicle running state; steady oil pressure computing means for computing a primary steady oil pressure supplied to the primary pulley and a secondary steady oil pressure supplied to the secondary pulley, according to an input torque inputted to the primary pulley and an actual pulley ratio; target shift speed determining means for determining a target shift speed based on the final pulley ratio; target stroke speed computing means for computing a target stroke speed of the primary pulley and/or secondary pulley from the target shift speed; target pulley rotation speed computing means for computing a target pulley rotation speed of the primary pulley, based on the vehicle running state; transitional oil pressure computing means for computing a transitional oil pressure correction amount which can attain the target shift speed, in response to the target pulley rotation speed of the primary pulley and the target stroke speed; and oil-pressure control means for setting one of the oil pressure supplied to the primary pulley and the oil pressure supplied to the secondary pulley, to the sum of the steady oil pressure and transitional oil pressure correction amount, so as to attain the final pulley ratio.