Toyota Jidosha Kabushiki Kaisha

Aisin Aw Co., Ltd.

Nobuhiro Sato

Atsushi Honda

Kazutoshi Nozaki

Kazuyuki Noda

Mikio Iwase

Akira Fukatsu

Tetsuya Yamaguchi

Kazuhisa Ozaki

Akiharu Abe

Minoru Todo

Masafumi Kinoshita

Takuya Fujimine

A hydraulic control apparatus, provided with a manual shift valve that outputs a forward range pressure and a reverse range pressure, and a linear solenoid valve that outputs an engagement pressure to the hydraulic servo that engages during reverse travel when energized, includes a fourth clutch relay valve that is interposed between the linear solenoid valve and the hydraulic servo. The fourth clutch relay valve communicates an engagement pressure of the linear solenoid valve to the hydraulic servo by locking in the normal position when a signal pressure of the solenoid valve is input, and communicates a reverse range pressure to the hydraulic servo by being switched to a fail position by the reverse range pressure during a failure in which the fourth clutch relay valve is de-energized. Thereby, it is possible to establish a reverse speed during a failure in which the solenoid valve is de-energized.

Hydraulic control apparatus for an automatic transmission

A hydraulic control apparatus for an automatic transmission is provided with a solenoid valve that outputs a signal pressure during a failure and does not output a signal pressure during normal operation and a first clutch apply relay valve that switches between a normal position (the right half position) and a fail position (the left half position) based on this signal pressure are provided. During a failure, fail-safe control is carried out by the first clutch apply relay valve switching to the fail position. The first clutch apply relay valve inputs the engagement pressure of the hydraulic servo from the linear solenoid valve when in the normal position, and is locked in the normal position. Thereby, while the first clutch is engaged, the second brake apply control valve can be switched by the signal pressure of the solenoid valve.

A hydraulic control apparatus for an automatic transmission comprises a linear solenoid valve for outputting a control pressure, a primary regulator valve for regulating a line pressure in accordance with the control pressure, and a secondary regulator valve for regulating a secondary pressure in accordance with the control pressure, the secondary pressure being supplied to a lock-up clutch and a torque converter. A spool of the secondary regulator valve is formed to comprise a large diameter portion and a small diameter portion, thereby eliminating the need for components such as a sleeve, and the line pressure can be input into an oil chamber formed between the large diameter portion and small diameter portion.

Hydraulic control apparatus for automatic transmission

Growing community of inventors

Anjo, Japan

Nobuhiro Sato