摘要:
The method features in that the speed at which a shift actuator operates in effecting an upshifting is slower than the speed at which the shift actuator operates in effecting a downshifting.
摘要:
A starting valve has a start fluid pressure regulating state and a complete engagement fluid pressure regulating state and supplies a regulated fluid pressure to a hydraulic clutch. A shift operating mechanism comprises a rod movable within a reduction ratio select range and an overstroke range. A complete engagement control valve has a spool operatively connected with the rod. When the rod is disposed within the reduction ratio select range, the complete engagement control valve renders the starting valve operable in the complete engagement fluid pressure regulating state, while when the rod is disposed within the overstroke range, the complete engagement control valve renders the starting valve operable in the start fluid pressure regulating state.
摘要:
A hydraulic control system comprises a line pressure regulator valve which uses a spring has non-uniform spring rate. A spring is compressed between a pressure regulating element and a member movable responsive to a reduction ratio between drive and driven pulleys. A length of the spring is varied by the member with variation in the reduction ratio. The line pressure regulator valve generates a line pressure having non-linear characteristic with respect to the variation in the reduction ratio.
摘要:
A continuously variable transmission includes a hydrodynamic device, such as a fluid coupling or a torque converter, having a lock-up clutch. The reduction ratio of the continuously variable transmission is controlled by a shift motor. The shift motor is controlled such that each of rotary positions thereof corresponds uniquely to a desired optimum reduction ratio. Upon detecting a state wherein a rapid down shift is needed, the lock-up clutch is temporarily disengaged to allow the hydrodynamic device to slip during the rapid down shift.
摘要:
A control system for a hydraulic clutch comprises a starting valve and a complete engagement control valve coupled with the starting valve. The starting valve supplies to the clutch a regulated fluid pressure which is elevated in accordance with a revolution speed of an engine when it is in a start fluid pressure regulating state and which is higher than the regulated fluid pressure provided in said start fluid pressure regulating state when it is in said complete engagement fluid pressure regulating state when it is in a complete engagement fluid pressure regulating state. The complete engagement control valve shifts the starting valve from the start fluid pressure regulating state to the complete engagement fluid pressure regulating state when the vehicle speed exceeds a complete engagement vehicle speed.
摘要:
A continuously variable transmission includes a V-belt running over a drive pulley and a driven pulley. Upon rapid shifting in reduction ratio, a line pressure is increased temporarily to provide a proper V-belt gripping force to prevent slipping of the V-belt.
摘要:
The control system comprises a starting valve wherein an engine revolution speed indicative fluid pressure and a start adjustment fluid pressure act on a spool of the valve against each other. The starting valve generates a start pressure to be used as a clutch engagement pressure for a hydraulic clutch. The start adjustment fluid pressure is generated by a start adjustment valve coupled with an electronic control unit. Under the control of the electronic control unit, the start adjustment offsets a variation in the engine revolution fluid pressure when the engine idles with the vehicle at a standstill.
摘要:
The reduction ratio of a continuously variable transmission is controlled by a stepper motor. The stepper motor is controlled such that each of rotary positions thereof corresponds uniquely to a desired optimum reduction ratio indicative signal indicative of a desired optimum reduction ratio. The desired optimum reduction ratio indicative signal is generated for operating condition of an automotive vehicle.
摘要:
A method and an apparatus for controlling the reduction ratio of a continuously variable transmission are disclosed wherein normally the reduction ratio is controlled in response to a desired optimum reduction ratio indicative signal obtained by retrieving the data stored in a memory versus engine load and vehicle speed, but when more vehicle acceleration is needed, the reduction ratio is controlled by a corrected desired optimum reduction ratio indicative signal to increase the reduction ratio.
摘要:
A control system for a continuously variable V-belt transmission is disclosed wherein for the purpose of preventing an undesirable rapid drop in pressure in a cylinder chamber of a drive pulley a flow restrictor is provided to restrict the flow of oil discharged from the cylinder chamber upon rapid change in reduction ratio of the continuously variable V-belt transmission.