Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Hiroshi Takuma

Yoichi Furuichi

Shoji Kan

Takahiro Taki

Takeshi Kitagawa

Shift control apparatus for automatic transmission for vehicle

Hydraulic pressure supplied to the frictional engaging element of an automotive transmission is corrected to a higher value in the event that the engine is started after a long standstill condition and the first speed ratio is selected, thereby reducing speed-shift shocks when the engine is started from a standstill condition and the first speed ratio is selected.

In an automatic transmission for a vehicle having at least one frictional engaging element and an electromagnetic valve to control hydraulic pressure supplied to the frictional engaging element and achieving a plurality of speed ratios including a predetermined speed ratio achieved by engaging the frictional engaging element, a shift control apparatus includes retardation rate detection means for detecting retardation rate of the vehicle and electromagnetic valve control means for controlling the electromagnetic valve according to the value detected by the retardation rate detection means, and hydraulic pressure supplied to the frictional engaging element is corrected by the electromagnetic valve through electromagnetic valve control means according to the retardation rate of the vehicle detected by the retardation rate detection means, thereby reducing speed-shift shocks during a down-shift in association with retardation of the vehicle.

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Kyoto, Japan

Hiroshi Takuma