摘要:
A hydraulic control apparatus for a power transmitting system for an automotive vehicle having a continuously variable transmission which has a first and a second shaft, a pair of variable-diameter pulleys provided on the first and second shafts, a belt connecting the pulleys, and a pair of hydraulic actuators for changing diameters of the pulleys, wherein a tension of the belt is controlled by regulating an actuating pressure in a driven side actuator of the hydraulic actuators which is provided on a driven one of the two shafts. The apparatus includes a pressure regulating valve which has a valve spool for regulating the actuating pressure in the driven side actuator, and a pressure-reducing chamber for receiving a pressure-reducing pilot pressure for biasing the spool for reducing the actuating pressure. The apparatus further includes a pilot pressure generator for generating the pressure-reducing pilot pressure to be applied to the pressure-reducing chamber, when the detected vehicle running speed exceeds a predetermined value.
摘要:
A hydraulic control apparatus for a vehicle power transmitting system having a continuously variable transmission having a first and a second shaft, a pair of variable-diameter pulleys provided on the shafts, a belt connecting the pulleys, and two hydraulic actuators for changing diameters of the pulleys. The apparatus includes a directional control valve for supplying a fluid from a pressure line to one of the two actuators while discharging the fluid from the other actuator, a first fluid passage connected to the directional control valve, for primarily supplying the fluid from the pressure line to a driving side actuator of the two actuators which is provided on a driving one of the first and second shafts, a second fluid passage connected to the directional control valve, for primarily supplying the fluid from the pressure line to a driven side actuator of the hydraulic actuators, and a flow restrictor for restricting a flow of the fluid through the first fluid passage so that a fluid flow resistance of the first fluid passage is higher than a fluid flow resistance of the second fluid passage.
摘要:
A hydraulic control apparatus for a vehicle power transmitting system having a fluid coupling equipped with a lock-up clutch, and a transmission to which power is transmitted from an engine of the vehicle through the fluid coupling. The fluid coupling has an engaging chamber and a releasing chamber for engaging and releasing the lock-up clutch. The apparatus includes a discharge passage communicating with the engaging chamber, for normally draining the engaging chamber to a drain, to thereby normally release the lock-up clutch, and a rapid release valve connected to the discharge passage. The rapid release valve operates to by-pass the discharge passage to the drain therethrough, for thereby rapidly draining the engaging chamber to rapidly release the lock-up clutch. A lock-up pressure regulating valve is provided for regulating a lock-up clutch pressure applied to the fluid coupling, normally to a first value, and upon operation of the rapid release valve, to a second value higher than the first value.
摘要:
An apparatus for controlling a vehicle continuously variable transmission, including a directional control valve having a first spool movable between a shift-down and a shift-up position, a flow control valve including a second spool movable between a flow-restricting and a non-restricting position, and a first and a second solenoid-operated valve for applying an actuating pressure to the first and second spools. The directional and flow control valves and the solenoid-operated valves are adapted such that the first and second spools are moved toward the shift-up and flow restricting positions, respectively, when the actuating pressure is not applied to the spools, or when solenoid coils of the two solenoid-operated valves are both off. The directional control valve may have a shift-down chamber for receiving a pilot pressure to move the first spool to the shift-down position when a failure of one of the solenoid coils exists while the vehicle speed is lower than a predetermined limit.
摘要:
A shift control apparatus for controlling a continuously variable transmission device including a continuously variable transmission mechanism having rotary elements and operable to transmit a rotary motion of a drive power source of an automotive vehicle to a drive wheel of the automotive vehicle, such that a speed ratio of said mechanism is continuously variable, the shift control apparatus includes a power-transmission-state determining device for determining whether the mechanism is placed in a non-power-transmitting state, a speed-ratio determining device for determining whether the mechanism is placed in a lowest-speed position, a rotation-stop detecting device for determining whether the rotary elements are at rest, and a compulsory-speed-ratio-change implementing device for effecting a compulsory shift-down action of the mechanism toward the lowest-speed position when the mechanism is placed in the non-power-transmitting state while the mechanism is not placed in the lowest-speed position and while the rotary elements of the mechanism are at rest.
摘要:
An apparatus for controlling a hydraulic clutch, including a two-position clutch control valve, a two-position rapid clutch release valve, and a first fluid passage system for releasing the clutch, a second fluid passage system for engaging the clutch, and a third fluid passage system for releasing the clutch. These three passage systems for feeding and discharging a fluid into and from the clutch are selected by respective three combinations of the operating positions of the two valves. Normally, a predetermined one of the first and third passage systems is selected for releasing the clutch, and the other of these two systems is selected in the event of a trouble with the valves.
摘要:
A hydraulic control apparatus for a vehicle power transmission for transmitting power from an engine to a drive wheel a reversing mechanism having a reverse position established by a hydraulic actuator. The apparatus includes a reverse inhibit valve disposed in a hydraulic line leading to the hydraulic actuator and having a reverse inhibit position for inhibiting the mechanism from being placed in the reverse position and a non-inhibit position for permitting the mechanism to be placed in the reverse position. The apparatus uses a first and a second pilot pressure generating device for producing a first and a second pilot pressure, respectively. A relay valve is provided for producing a first hydraulic signal for establishing the reverse inhibit position of the reverse inhibit valve, based on one of combinations of operating states of the two pilot pressure generating devices, and a second hydraulic signal for establishing the non-inhibit position, based on the other combinations.
摘要:
Herein disclosed is a fluid coupling which comprises: a pump impeller connected to the output shaft of an engine; and a turbine runner for transferring a working fluid to and from the pump impeller. On the pump impeller and the turbine runner, respectively, there are arranged a pump blade and a turbine blade without any inner core for guiding the flow of the working fluid inside of the pump impeller and the turbine runner. By bending at least one of the working fluid outlet side of the pump blade and the working fluid inlet side of the turbine blade, there is formed transfer limit means for limiting the transfer of the working fluid when the fluid coupling is in a stalling state.
摘要:
In a vehicular belt-driven continuously variable transmission, belt squeezing force is inhibited from becoming excessive and a safety factor, with respect to belt slip, of belt squeezing force applied to a transmission belt (48) is reduced to a value that is less than or equal to 1.5 by reducing a pressure receiving area (SOUT) of an output side hydraulic cylinder (46c). As a result, a centrifugal hydraulic pressure canceller chamber on a secondary pulley side (46) can be eliminated thus simplifying the structure of the vehicular belt-driven continuously variable transmission, while belt squeezing force can be appropriately controlled.
摘要:
A fluid coupling has capacity coefficients in forward and reverse driving which can be arbitrarily selected to comply with demand for a wide variety of characteristics in accordance with the intended application. Pump blades Bp and/or turbine blades Bt are inclined in the direction of rotation of pump impeller P and a turbine runner T with inclination angles .theta..sub.2p and .theta..sub.2t with respect to normal lines Lp and Lt of the pump and turbine, respectively. Transfer of working fluid between the pump impeller P and the turbine runner T is thereby smoothened or suppressed in accordance with the inclination angles .theta..sub.2p and .theta..sub.2t, and thus the capacity coefficients in both forward and reverse driving can be arbitrarily selected and fixed.