摘要:
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 before eventually causing the controller unit to control the clutch pressure in accordance with the calculated clutch duty ratio.
摘要:
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.
摘要:
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.
摘要:
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. The control system implements the sequential steps of (a) delivering a variety of signals denoting the status of the driven vehicle to said controller unit, and (b) causing the controller unit to output signals to the oil-pressure circuit when the controller unit identifies the presence of a hold mode before eventually causing the oil-pressure circuit to control the clutch pressure to a predetermined level.
摘要:
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.
摘要:
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. In this method, first to third three-way electromagnetic pressure control valves control the oil pressure and an electronic control unit (ECU) controls the electromagnetic valves, and driving frequencies of the valves are switched by the ECU in accord with the oil temperature and/or vehicle speed so that the hydraulic clutch is smoothly and effectively operated, the lifetime of the electromagnetic valves is extended, and vibration of the vehicle body due to pressure fluctuation in the hydraulic circuit is prevented.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. In this method, first to third three-way electromagnetic pressure control valves control the oil pressure and an electronic control unit (ECU) controls the electromagnetic valves, and driving frequencies of the valves are switched by the ECU in accord with the oil temperature and/or vehicle speed so that the hydraulic clutch is smoothly and effectively operated, the lifetime of the electromagnetic valves is extended, and vibration of the vehicle body due to pressure fluctuation in the hydraulic circuit is prevented.