Other

Ryoji Habuchi

Akihito Iwata

Hiroshi Tanaka

Masashi Hattori

Norio Imai

Junichi Tokunaga

A hydraulic controller of an automatic transmission which releases the lockup clutch when it fails. An output port of a solenoid valve is connected to a port of a lockup control valve and a port of a garage shift valve. An output port of a solenoid valve is connected to a port of the lockup control valve and a port of the garage shift valve. At least one of the solenoid valves is freely duty-controlled. A pattern, which enables regular control of the automatic transmission in normal operation and does not allow the lockup clutch to change from its released state to its engaged state, is selected for use from among plural combinations of signal pressures of the solenoid valves.

Hydraulic pressure controller for automatic transmission

When an SLT pressure of a linear solenoid valve is input into a control oil chamber of a garage shift control valve, and a direct control pressure from the garage shift control valve is output to a clutch or a brake, a hydraulic controller inputs the direct control pressure into a control oil chamber and executes feedback-control. Also, when a range pressure of a clutch modulator valve is output to the clutch or the brake by switching the garage shift valve, the hydraulic controller inputs the range pressure, which is higher than the SLT pressure, into the control oil chamber and fixes the garage shift control valve.

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Toyota, Japan

Ryoji Habuchi