Mazda Motor Corporation

Kyosuke Mori

Shinya Kamada

Takayuki Sumimoto

Minoru Kuriyama

Daisaku Moriki

Minji Sakaki

Masaharu Sakoda

An automatic transmission control system couples frictional coupling element, such as a low reverse brake, so that the frictional coupling element provides different torque transmissive capacities in a reverse gear and a first gear in which engine braking is available. The system includes a pressure regulator which regulates a coupling pressure, by which the frictional coupling element is coupled and which is controlled and gradually supplied to the frictional coupling element, during a shifting of the automatic transmission to a reverse gear. The pressure regulator is disabled from regulating the coupling pressure in the reverse gear.

Automatic transmission control system

An automatic transmission control system includes a hydraulic circuit for controlling coupling pressure supplied to frictional coupling elements of the automatic transmission, which are selectively coupled and uncoupled so as to shift the automatic transmission into desired gears. The hydraulic circuit has a solenoid valve, for regulating a principal hydraulic pressure to provide a control pressure in accordance with vehicle driving conditions. The coupling pressure, supplied to a frictional coupling element, is regulated by a regulating valve in accordance with a control pressure level, and during shifting of the automatic transmission, is supplied through an accumulator whose back pressure is controlled in accordance with the control pressure by a control valve.

Automatic transmission control system having two accumulators for four

An automatic transmission shift control system controls a line pressure for initiating a shift of an automatic transmission so that a duration between initiation of the shift and termination of a torque decline during the shift falls within a predetermined shift initiation time period. Also, a line pressure is controlled by the system for terminating a shift of the automatic transmission so that a duration between termination of a torque decline and termination of the shift falls within a predetermined shift termination time period. Both of the line pressures are used in a following shift control of the automatic transmission.

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Kitakyushu, Japan

Kyosuke Mori