Other

Masahiro Itou

Naoyuki Fukaya

Yoshihiro Iijima

Mikio Iwase

Hiromichi Kimura

Kazuhisa Ozaki

Kazuyuki Watanabe

Koichi Tanaka

Hideaki Ogasawara

Shigeki Hiramatsu

Kazunori Ishikawa

Keizo Kobayashi

Takenori Kanou

An automatic transmission and method including a plurality of hydraulic servos which respectively engage and disengage a plurality of frictional engagement elements, a first solenoid valve for gear shifting which is used for generating a hydraulic pressure supplied to a predetermined hydraulic servo, a second solenoid valve for lock-up which is used for generating a hydraulic pressure supplied to a fluid transmission apparatus for executing a lock-up, a hydraulic control apparatus, a first connector which connects the first solenoid valve and the hydraulic control apparatus, a second connector which connects the second solenoid valve and the hydraulic control apparatus, a failsafe mechanism which achieves a predetermined shift range in a high-speed-side when the first connector is disconnected and a gear shift processing mechanism which achieves a predetermined shift range among a plurality of shift ranges when the second connector is disconnected.

Automatic transmission with a hydraulic control apparatus

To prevent the neutral state from being formed in a change gear apparatus and allow the obtaining of an intended gear change appropriately during a servo malfunction. Hydraulic servos engage and disengage a plurality of friction engagement elements; a hydraulic pressure supply system supplies the hydraulic servo of a predetermined friction engagement element with hydraulic pressure; and an auxiliary hydraulic pressure supply systems supplies a predetermined hydraulic servo with another hydraulic pressure, in the case where the hydraulic pressure supply system is placed in a first unsupplied state where the hydraulic pressure supply system cannot supply the hydraulic servo of the predetermined friction engagement element with hydraulic pressure. The auxiliary hydraulic pressure supply system does not supply the predetermined hydraulic servo with the other hydraulic pressure, in the case that the hydraulic pressure supply system is placed in a second unsupplied state where the hydraulic pressure supply system does not supply the hydraulic servo of the predetermined friction engagement element with hydraulic pressure.

Hydraulic control apparatus for automatic transmission

This invention provides a switch valve which can increase durability without causing driver discomfort at a time when a failure occurs. The switch valve has a spool is formed by a spool portion and a plunger which is arranged so as to freely abut against the spool portion. The switch valve also include a spool surrounding portion surrounding the spool and provided with a plurality of land portions. The spool selectively adopts a position at a normal, non-failure state and a position at a fail state. In the position at the normal state, at least one corner portion of the land in the plunger protrudes from an end portion of the corresponding land portion. Because a stepped wear portion is not formed on an inner peripheral surface of the land portion, foreign materials, such as wear powders or the like, do not enter a portion between an outer peripheral surface of the land and the inner peripheral surface of the land portion when the failure occurs.

Switch valve

A hydraulic control unit including a hydraulic servo for engaging and disengaging each friction engagement element, hydraulic pressure supply device for supplying hydraulic pressure to a hydraulic servo of a predetermined friction engagement element selected according to a gearshift position to be achieved, failure detection device for detecting a failure has occurred in the hydraulic pressure supply device, and fail-safe device for preventing interlock that occurs due to a plurality of friction engagement elements being engaged, and also prevents a gearshift from a high-speed position to a low-speed position, when the failure detection device detects that a failure has occurred.

Hydraulic control unit for automatic transmission

A hydraulic control device for an automatic transmission that can ensure power transmission when a failure occurs to the solenoid valve of the hydraulic control device, the hydraulic control device having a plurality of hydraulic servos for engaging and disengaging a plurality of friction engagement elements in accordance with the supply and discharge of a hydraulic pressure so as to prevent interlock from occurring to the transmission, a solenoid valve for generating a predetermined hydraulic pressure and supplying the predetermined hydraulic pressure to a hydraulic servo selected in correspondence with a target gear ratio and fail-safe means for supplying fail-safe hydraulic pressure to at least two hydraulic servos selected to attain an arbitrary gear ratio when a failure occurs to the solenoid valve and power transmission thereby becomes impossible. Further, the hydraulic control device has a plurality of solenoid valves for supplying the predetermined hydraulic pressure to the plurality of hydraulic servos and a shutoff valve, disposed between a hydraulic pressure source and one of the solenoid valves, for shutting off supply of hydraulic pressure to that one solenoid valve when hydraulic pressure to be supplied to the hydraulic servos selected in correspondence with the target gear ratio and hydraulic pressure to be supplied to the other hydraulic servos are generated.

Growing community of inventors

Anjo, Japan

Masahiro Itou