Abstract: A continuously variable transmission which effects a speed change by increasing and decreasing the width of a groove between a fixed pulley part and a movable pulley part. A belt ratio controller for the transmission uses oil pressure to increase and decrease the rotating radius of a belt wound on the pulley parts, the belt controller controlling the belt ratio to a target belt ratio value set based on the opening of the throttle when starting on a road having a small road surface friction coefficient.

Abstract: A continously variable transmission has a fixed pulley piece and has a movable pulley piece which is supported for movement toward and away from the fixed pulley piece, the width of a groove between the pulley pieces being increased or decreased in order to increase or decrease the radius of rotation of a belt looped around a driving side pulley and a driven side pulley which include the fixed and movable pulley pieces to thereby vary a belt ratio. A hydraulic clutch is engaged and disengaged under control of a clutch pressure in order to vary a driving force output by the continuously variable transmission, and a control arrangement controls and hydraulic clutch so that creep caused by slippage of the hydraulic clutch in a hold mode during a reverse gear operation of the continuously variable transmission is larger than creep caused by slippage of the hydraulic clutch in a hold mode during forward gear operation of the continuously variable transmission.

Abstract: A hydraulic control method is applied to a continuously variable speed change gear mechanism including a pulley having a fixed pulley member fixed to a rotary shaft and a movable pulley member movable by oil pressure toward and away from the fixed pulley member so that a groove width between the fixed and movable pulley members is decreased or increased to thereby reduce or increase the effective rotational radius of a belt extending between the pulley members and thus change a change gear ratio and control the gear change.

Abstract: A continuously variable transmission has a fixed pulley piece and a movable pulley piece supported on the fixed pulley piece so that the movable pulley piece can be moved toward and away from the fixed pulley piece, the width of a groove between the pieces being increased or decreased by changing hydraulic pressure so that the rotational radius of a belt looped around the pulleys is increased or decreased to vary a belt ratio. A clutch pressure control device includes a hydraulic clutch for which engagement and disengagement is controlled according to various control modes, and a control arrangement which calculates a target clutch pressure with reference to a slip amount of the hydraulic clutch and which feedback controls the target clutch pressure so that the slip amount of the clutch is maintained substantially constant.

Abstract: A method of controlling a clutch of a continuously variable transmission system which controls a transmission system by either expanding or contracting the width of a channel between a stationary pulley member and an axially movable pulley member to expand or contract the radius of rotation of a belt wound on the pulleys to eventually vary the belt ratio. The continuously variable transmission system includes a controller unit which executes a control operation by feeding actually detected clutch pressure back to an objective clutch pressure, and an oil-pressure circuit which controls oil pressure in response to signals from the controller unit.

Abstract: A continuously variable transmission includes a driving side pulley and a driven side pulley each having a fixed pulley part and having a movable pulley part supported for movement toward and away from the fixed pulley part, the width of a groove between the pulley parts of each pulley being increased and decreased to increase the decrease at each pulley the rotating radius of a belt wound around both of the pulleys to change a belt ratio. A revolution controller for the transmission limits the rate of change of a target number of revolutions for an engine driving the transmission to a rate limit lower than a prescribed rate when the target number of revolutions of the engine specified by a speed change schedule map based on a throttle opening and a vehicle speed is changed during travel of the vehicle.

Abstract: A hydraulic control method is applied to a continuously variable speed change gear mechanism including a pulley having a fixed pulley member fixed to a rotary shaft and a movable pulley member movable by oil pressure toward and away from the fixed pulley member so that a groove width between the fixed and movable pulley members is decreased or increased to thereby reduce or increase the effective rotational radius of a belt extending between the pulley members and thus change a change gear ratio and control the gear change.

Abstract: A hydraulic control method is applied to a continuously variable speed change gear mechanism including a pulley having a fixed pulley member fixed to a rotary shaft and a movable pulley member movable by oil pressure toward and away from the fixed pulley member so that a groove width between the fixed and movable pulley members is decreased or increased to thereby reduce or increase the effective rotational radius of a belt extending between the pulley members and thus change a change gear ratio and control the gear change.

Abstract: A method and apparatus for controlling line pressure of a belt-type continuously variable transmission system. The apparatus controls line pressure by raising it by a specific amount in the presence of predetermined conditions when slipping of a clutch is detected during the drive mode of the system so that optimum clutch engagement can eventually be implemented.

Abstract: A novel method of controlling a continuously variable transmission system by executing sequential steps including delivering a throttle-aperture detection signal and a vehicle-speed detection signal to a controller unit; determining an optimum objective number of engine revolution in reference to a first objective number of engine revolution set by the throttle-aperture detection signal and a second-objective number of engine revolution set by the vehicle-speed detection signal and in accordance with an instruction limiting the number of engine revolution at the shift position; and executing control of the transmission system in response to the vehicle-speed detection signal.

Abstract: A method of controlling clutch pressure in a continuously variable transmission system which can expand and contract the width of a channel between a stationary pulley member and a movable pulley member movable relative to the stationary pulley member in order to respectively contract and expand a radius of travel about the pulleys of a belt engaging the pulleys before eventually varying a belt ratio, a clutch-pressure control arrangement of the continuously variable transmission system including a controller unit which effects control by feeding an actually-detected clutch pressure back in determining an objective clutch pressure and including an oil-pressure circuit which controls oil pressure in response to signals from the controller unit; the method comprising the step of: causing the controller unit to calculate a clutch duty ratio in reference to the objective clutch pressure and an objective line pressure when a pressure sensor detecting the actually-detected clutch pressure outputs an abnormal signal