Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Aisin-warner Kabushiki Kaisha

Aisin-warner K.k.

Aisin Seiki Kabishuki Kaisha

Takahiro Sakai

Isamu Minemoto

Masato Shimei

Atsuo Isoda

Tooru Matsubara

Yutaka Taga

Kazumasa Tsukamoto

Shiro Sakakibara

Yoshio Hasegawa

Yasunobu Ito

Yoichi Hayakawa

Yukio Terakura

Kazunari Adachi

Yoshikazu Tanaka

Yuichi Kato

Hiromi Hasegawa

Shigeki Goto

Koichi Miyamoto

Yoshiyuki Onimaru

Yoshinobu Iwase

Atsuo Okumura

Yasuo Shirai

Makoto Nakayashiki

Masahiko Nakagawa

Takanao Suzuki

Atuo Okumura

Masatoshi Nakamura

Takashi Hirano

A variable oil pump includes a pump rotor housed in a housing and rotationally driven, an adjustment ring that adjusts an amount of oil discharged from the pump rotor by being displaced under hydraulic pressure supplied to a hydraulic chamber between the housing and the pump rotor in a state where the pump rotor is rotatably held from an outer peripheral side, and a vane provided in a portion where the adjustment ring and the housing face each other and that seals oil leakage to an outside of the hydraulic chamber. The adjustment ring includes a vane holding portion that holds the vane and an oil passage through which the hydraulic pressure in the hydraulic chamber is drawn into the vane holding portion.

Variable oil pump

A relief valve includes a housing including an internal flow passage through which a working fluid flows, and a relief port discharging the working fluid from the internal flow passage, and a valve body including a first pressure-receiving portion a second pressure-receiving portion receiving pressure with a pressure-receiving area that is larger than a pressure-receiving area of the first pressure-receiving portion, and a first recessed portion formed at the second pressure-receiving portion at an opposite side relative to a pressure-receiving surface of the second pressure-receiving portion and including a closed-end cylindrical shape. The relief valve includes a biasing force adjustment mechanism including a spring of which one end is held at the first recessed portion, a support portion retaining the other end of the spring and including a closed-end cylindrical shape, and a motor adjusting a rotational angle and causing the support portion to reciprocate.

Relief valve

A control apparatus for a vehicular automatic transmission includes a control portion that executes a neutral control in which the control portion places the automatic transmission in a neutral state by reducing an application load on a frictional apply device inside the automatic transmission when the vehicle is stopped. The control portion ends the neutral control when a torque transmitted to the frictional apply device has been continually equal to, or greater than, a predetermined value for a consecutive predetermined of time. As a result, by considering the torque transmitted to the frictional apply device in addition to the continuation time of the neutral control, it is possible to more precisely grasp the state of the frictional apply device. In other words, it is possible to execute, as quickly as possible, neutral control for an extended period of time while ensuring durability of the frictional apply device.

Control apparatus and method for vehicular automatic transmission

A shift control unit which improves the shift feeling of an automatic transmission includes an operation control device for placing a frictional engaging element in a slow drain state during a timing time decided by a timing time deciding device and in a quick drain state when the timing time has elapsed. The shift control unit is provided further with a computing device for computing the power-off engine speed necessary for outputting a small range upper limit value of a turbine torque from a number of revolutions of the turbine of the torque converter and from the performance characteristic of the torque converter, and an auxiliary operation control device for comparing the power-off engine speed and actual engine speed and for running the operation control device when the actual engine speed is equal to or greater than the power-off engine speed to place the frictional engaging element into the quick drain state immediately without running the operation control device when the actual engine speed is below the power-off engine speed.

Shift control unit of automatic transmission

A diagnosing apparatus for diagnosing a vehicle automatic transmission system including an automatic transmission having frictional coupling devices, and solenoid-operated valves for controlling the frictional coupling devices to shift the automatic transmission according to shift commands generated by a control device, the apparatus including a speed detector for detecting an engine speed of the vehicle, a device for determining a reference range of the engine speed within which the engine speed is expected to fall when the transmission is placed in a position selected by a shift command, a device for determining whether a predetermined running condition of the vehicle is satisfied, and a defect detector for determining whether there exists a defect associated with the automatic transmission system, depending upon whether the detected engine speed is held within or outside the determined reference range when the predetermined vehicle running condition is satisfied.

Apparatus for diagnosing automatic transmission based on engine speed as

A control apparatus for an automatic transmission having a set of frictional engagement elements arranged to be selectively engaged or disengaged in shift-up operation of the transmission, and a shift timing valve arranged to be switched over by hydraulic pilot pressure applied there-to under control of a solenoid valve for switching over discharge of fluid under pressure from one of the frictional engagement elements to be disengaged in the shift-up operation from a slow-drain condition to a quick-drain condition. The control apparatus is designed to detect a drive torque of a vehicle engine, to determine a timing period for energization of the solenoid valve in the shift-up operation in accordance with the drive torque of the vehicle engine, to maintain the solenoid valve in its deenergized condition during the timing period, and to energize the solenoid valve upon lapse of the timing period.

Control apparatus for automatic transmission

A hydraulic control system for a four-wheel drive torque transfer mechanism for a vehicle, including an automatic transmission, a transfer mechanism having gear positions of a two-wheel drive direct-coupling mode H.sub.2, a four-wheel drive direct-coupling mode H.sub.4 and a reduced-speed four-wheel drive mode L.sub.4, and a hydraulic control circuit for controlling the transmission and the transfer mechanism. The transfer mechanism includes a reduction gear mechanism, a first output shaft, a second output shaft rotationally connectible to the first output shaft through a link mechanism, a four-wheel drive clutch for releasably coupling the first and second output shafts, a direct-coupling clutch for releasably coupling an input shaft of the reduction gear mechanism with the first output shaft, and a reduction brake for setting the reducing gear mechanism in a gear train of the reduced-speed mode. The hydraulic control circuit includes an inhibitor valve which is supplied with governor pressure and which selectively applies pressurized fluid to one of the servomotors of the direct-coupling clutch and reduction brake while draining the other servomotor, the inhibitor valve feeding pressurized fluid continuedly to the servomotor of the direct-coupling clutch if manual shift of the transfer mechanism selects the mode L.sub.4 when the governor pressure is higher than a predetermined level, and instead feeding pressurized fluid to the servomotor of the reduction brake and draining the servomotor of the direct-coupling clutch when the governor pressure drops below the predetermined level.

Hydraulic control system for four-wheel drive torque transfer mechanism

In an upshift timing system which provides a drain passage at higher flow resistance for a first friction engaging device to be disengaged when a hydraulic fluid pressure of a second friction engaging device to be engaged supplied as an actuating pressure to a control port of an upshift timing control valve is less than a certain value and at lower flow resistance when the actuating pressure is greater than the certain value, the control port is supplied with the actuating pressure directly from a pressure chamber of the second friction engaging device via a passage which is separate from a passage which supplies actuating pressure from a pressure source to the pressure chamber of the second friction engaging device.

Transmission control system with separate shift timing control pressure

An automatic transmission has first and second pressure actuated friction engaging devices to provide a lower speed stage when the first friction engaging device is engaged and the second friction engaging device is disengaged, or vice versa; a speed shift valve which changes over supplying and exhausting hydraulic fluid pressure to and from the first and second friction engaging devices; a downshift timing system which provides lower flow resistance at lower road speed and higher flow resistance at higher road speed in a passage for supplying hydraulic fluid pressure to the first friction engaging device; an upshift timing system which provides higher flow resistance to a passage for exhausting hydraulic fluid pressure from the first friction engaging device before the hydraulic fluid pressure in the second friction engaging device increases to a predetermined value and lower flow resistance to the same drain passage when the hydraulic fluid pressure in the second friction engaging device has increased to the predetermined value; and a bypass passage which incorporates a one way valve and conducts hydraulic fluid from the first friction engaging device towards the speed shift valve by bypassing the downshift timing system.

Automatic transmission hydraulic pressure control system with one-way

A parking device for an automatic transmission system in automotive vehicles includes a parking gear connected to the engine output shaft, a pawl having one end pivotally mounted to the transmission housing and the other end pivotable towards and away from the parking gear, and a parking cam operatively associated with the pawl and movable axially of the gear for bringing the pawl into and out of engagement with the parking gear. A cam guide and a reaction supporting bracket are retained by a plurality of bolts and by at least one boss having a flat surface and affixed to the transmission housing so as to be situated on the side of the pawl opposite the parking cam.

Parking device

A one-way brake having end bearings the support wall of each of which is protruded at the inner race side portion thereof in the outward direction with respect to a space between inner and outer races from that surface of the support wall which is contacted by a support means connected to the outer race, to thereby increase the area of that portion of the inner race which is in sliding contact with an inner rib of the support wall. Accordingly, the wear resistance and stiffness of the end bearings can be increased without increasing an attaching space.

One-way brake

A hydraulic pressure control device for use, for example, in an automatic transmission, in which a line pressure to be supplied from a hydraulic pressure source to a hydraulic pressure servo-device is controlled in three stages by means of a main spool which is displaced in a bleed-off valve of the line pressure by a subsidiary spool under a varying hydraulic control pressure. The subsidiary spool has at least one land forming a piston slidingly fitted in a movable sleeve having a closed end, the movable sleeve also forming a piston by being in turn slidingly fitted for limited movement in a stationary sleeve having a closed end. A first space between the outer wall of the closed end of the movable sleeve and the inner wall of the closed end of the stationary sleeve, and a second space within the piston chamber of the movable sleeve have ports for the introduction of hydraulic control pressure. A spring is confined between the subsidiary spool and the movable sleeve with an initial load for urging the movable sleeve away from the main spool and minimizing the first space. The initial load on the spring and the diameter of the spaces are so determined that an increasing hydraulic control pressure displaces only the spools until the product of the control pressure and the difference in the areas of the cross sections of the spaces exceeds the initial load on the spring. Further increase of the control pressure displaces both the movable sleeve and the subsidiary spool to the limit of movement of the movable sleeve, the movement of the spools being a function of the strain on the spring. Further increase of the control pressure acts to move only the subsidiary spool and thereby the main spool. The control device preferably includes a second land on the subsidiary spool operating in an additional space of larger diameter in the movable sleeve and an annular space between the movable sleeve and the stationary sleeve. Both the additional space and the annular space are accessed to a second control pressure for additional displacement of the subsidiary spool and thereby of the main spool.

Growing community of inventors

Toyota, Japan

Takahiro Sakai