Toyota Jidosha Kabushiki Kaisha

Masami Sugaya

Yoshinobu Soga

Katsumi Kouno

Yuji Hattori

Susumu Okawa

Kunio Morisawa

Ryoji Habuchi

Nobuyuki Kato

Daisaku Sawada

Hiroshi Itoh

Yuji Iwase

Hiroyuki Nishizawa

Masataka Osawa

Kisaburo Hayakawa

Ryuji Imai

Takashi Hayashi

Katsumi Kono

Daisuke Inoue

Hideki Yasue

Kenji Matsuo

Hiroji Taniguchi

Tadashi Tamura

Shinya Kuwabara

Motoki Tabuchi

Naoki Moriguchi

Naoto Tanaka

Shinji Kasuga

Masabumi Nishigaya

Hiroshi Morioka

Takahiro Okada

Shoichi Sayo

Masanobu Kimura

Shuzo Sanda

A toroidal continuously variable transmission includes: an input disk; an output disk; a plurality of power rollers; a plurality of trunnions; an oil pump; a pressing hydraulic mechanism that moves and brings the input disk and output disk closer to each other; a shifting hydraulic mechanism that moves the trunnions forward and rearward; and a hydraulic control device that controls the pressing hydraulic mechanism and the shifting hydraulic mechanism by oil pressure. The hydraulic control device has an oil pressure regulation unit that sets an oil pressure in a shifting hydraulic line that is a hydraulic source of the shifting hydraulic mechanism to an oil pressure at which shifting control can be performed by the shifting hydraulic mechanism till the transmission of power between the input disk and output disk is interrupted when the operation of the oil pump is stopped.

Toroidal continuously variable transmission

A hydraulic control apparatus includes two oil flow control valves () each provided with a supply control portion () for controlling an oil supply from a pressurized oil source, and a discharge control portion () for controlling connection with a discharge passage. One of those oil flow control valves supplies/discharges oil to/from one of hydraulic chambers () that are oppositely formed in a hydraulic servo mechanism. An operation direction of the hydraulic servo mechanism is performed by operating one of the oil flow control valves. The other operation direction of the hydraulic servo mechanism is performed by operating the other oil flow control valve.

Hydraulic control apparatus and hydraulic control method

A controller determines a target gear ratio from an accelerator opening and a vehicle speed. The controller determines the stroke of a trunnion on the basis of the difference between present inclination and a target inclination, thereby to control stroke by a hydraulic control valve. The stroke is corrected according to input/output disc pushing force.

Speed change control apparatus for toroidal CVT

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.

Transmission shift control apparatus arranged to perform compulsory shift-down action of continuously variable transmission

The continuously variable belt transmission is provided with a fixed sheave and a movable sheave provided on a secondary shaft, a first hydraulic chamber that presses the movable sheave in an axial direction, a second hydraulic chamber that gives the movable sheave a pressing force acting in a direction opposite the pressing force given by the first hydraulic chamber, an oil passage connected to the second hydraulic chamber, and an oil receiver disposed along a path from the oil passage to the second hydraulic chamber. The oil receiver is attached to the secondary shaft, a bearing and a bulkhead are disposed on both sides of the oil receiver, an oil passage is provided in the secondary shaft, and a grooved portion provided in the oil receiver connects the second hydraulic chamber and the oil passage.

Continuously variable belt transmission

A hydraulic control apparatus for controlling a vehicle power transmitting system including a belt-and-pulley type continuously variable transmission and a torque converter provided with a lock-up clutch. The transmission includes a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of a transmission belt. The hydraulic control apparatus includes a lock-up clutch control valve which is selectively placed in an engaging and a releasing position for engaging and releasing the lock-up clutch, respectively, a slip control valve for controlling an amount of slipping of the lock-up clutch until the clutch is fully engaged, a pressure control device for raising the belt tensioning pressure so as to increase the tension of the transmission belt; and a pilot-pressure generating device for applying a pilot pressure simultaneously to the slip control valve and the pressure control means, so that the belt tensioning pressure is raised while the slip control valve controls the amount of slipping of the lock-up clutch.

Hydraulic control apparatus for power transmitting system including

A hydraulic control apparatus for a power transmitting system including a continuously variable transmission, a reversing device, and an auxiliary transmission, which apparatus includes: a solenoid valve for generating a pilot pressure for selectively placing the auxiliary transmission in high- and low-gear positions; high-gear and low-gear control valves normally operable based on the pilot pressure, to control high- and low-gear coupling devices of the auxiliary transmission to establish the high- and low-gear positions. The low-gear control valve is operated to engage the low-gear coupling device, when the low-gear control valve receives a pressure to be applied to the reversing device for forward run of the vehicle. The high-gear control valve may be operated to release the high-gear coupling device, when a thrust based on a pressure applied to the low-gear coupling device exceeds a predetermined value. The hydraulic control apparatus may further include a device for increasing a torque capacity of the high-gear coupling device during an engaging action thereof when a shift lever is operated to a reverse-drive position for reverse run of the vehicle.

Hydraulic control apparatus for continuously variable power transmitting

A hydraulic control apparatus for controlling a belt-and-pulley type continuously variable transmission of a motor vehicle having an engine, which transmission includes a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of a transmission belt. The hydraulic control apparatus includes an engine-output detecting valve for generating an engine output pressure indicative of a currently required output of the engine, a solenoid-operated valve for regulating a modified engine output pressure based on the engine output pressure generated by the engine-output detecting valve, and a pressure regulating valve for regulating the belt tensioning pressure based on at least the modified output pressure. The modified engine output pressure is obtained so that the belt tensioning pressure is controlled to an optimum level.

Hydraulic control apparatus for belt-and-pulley type continuously

A hydraulic control apparatus for controlling a continuously variable transmission of a motor vehicle, which transmission includes a first and a second shaft, a pair of variable-diameter pulleys provided on the first and second shafts, respectively, a transmission belt connecting the pulleys, and a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of the belt. The hydraulic control apparatus includes a reversal detecting device for determining whether a rotating direction of the pulleys has been reversed or not, and a pressure increasing device for temporarily increasing the belt tensioning pressure when the reversal detecting device detects reversal of the rotating direction of the pulleys.

A hydraulic control apparatus for controlling a continuously variable transmission for a motor vehicle, including a shift control valve device having a valve spool adapted to receive a first thrust corresponding to the currently required engine output and a second thrust corresponding to the input shaft speed of the transmission such that the spool is biased by the first and second thrusts in a shift-down and a shift-up direction for shifting down and shifting up the transmission, respectively, so that the speed ratio of the transmission is changed according to a distance of movement of the spool from a neutral position thereof in one of the shift-down and shift-up directions. The apparatus includes a device for producing a control pressure which varies with the vehicle speed, a gain changing spring for changing the distance of movement of the valve spool by the thrusts, and a device for permitting a biasing force of the spring to act on the spool, based on the control pressure, such that the distance of movement of the spool by the thrusts decreases with an increase in the vehicle speed.

Hydraulic control apparatus for continuously variable transmission,

A hydraulic control control apparatus for controlling a speed ratio of a vehicle continuously variable transmission, which includes a device for producing a first pressure varying with the input shaft speed of the transmission, a device for producing a second pressure varying with the currently required output of the vehicle engine, a device for producing a third pressure varying with the vehicle speed, such that a rate of increase in the third pressure is limited after the vehicle speed pressure reaches a predetermined upper limit which varies with the second pressure, and a shift control valve device including a valve spool operated to control the hydraulic actuator for changing the speed ratio so as to shift-down the transmission, in relation to an increase in the second pressure and an increase in the vehicle speed pressure, and changing the speed ratio so as to shift-up the transmission, in relation to an increase in the first speed pressure.

Hydraulic control apparatus for vehicle continuously variable

A power transmitting system for a motor vehicle, including a continuously variable transmission, a reversing device disposed downstream of the transmission, and a hydraulic control apparatus for controlling the transmission. The system includes a device for producing a required output pressure corresponding to a currently required acceleration value of the vehicle, a shift control valve for changing a speed ratio of the transmission, based on at least the required output pressure, such that the input shaft speed of the transmission increases with the currently required acceleration value and is higher when the shift lever is placed in a low-gear position than in a high-gear position, a device for producing a modified speed-ratio pressure which varies with the speed ratio when the speed ratio is higher than a predetermined value, and which is held constant when the speed ratio is lower than the predetermined value, and a device for applying the modified speed-ratio pressure to the shift control valve device in place of the required output pressure while the shift lever is placed in the low-gear position and when the required output pressure is lower than the modified speed-ratio pressure.

Vehicle power transmitting system with continuously variable

A hydraulic control apparatus for controlling the speed ratio of a vehicle continously variable transmission having a clutch device disposed in series with the transmission in a power transmitting line, to disconnect the power transmitting line when a shift lever is placed in a neutral position. The apparatus includes a first shift control valve for producing a first output for changing the speed ratio, based on a required output pressure corresponding to the currently required vehicle acceleration value, and a first input shaft speed corresponding to the transmission input shaft speed, a second shift control valve device for producing a second output for changing the speed ratio, based on a second input shaft speed pressure and an output shaft speed pressure corresponding to the input and output shaft speeds of the clutch device, respectively, so as to reduce a difference between the input and output shaft speeds of the reversing device, and a switching valve device for applying the first and second outputs to the transmission when the shift lever is operated to the drive and neutral positions, respectively.

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.

Hydraulic control apparatus for vehicle power transmitting system having

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.

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Susono, Japan

Masami Sugaya