Patent ID: 6041275
Filing Date: 2000-03-21
Classification: B60W,F16H,Y10T

Abstract:
An upshift control apparatus for use in an automatic transmission having an input shaft drivingly coupled to an engine and first and second torque transmitting elements operable on fluid pressure between engaged and released conditions for controlling at least the fluid pressure to the second element to an initial value to engage the second element to effect an upshift from a current gear ratio to a higher target gear ratio while releasing the first element without the use of a one-way clutch to release the first element while synchronizing rotation, comprising:means for detecting an upshift in the transmission;means for detecting the gear ratio changing during the upshift;means operable after the upshift is detected for detecting engine racing when the detected gear ratio is equal to or greater than a threshold value greater than a gear ratio existing before the upshift; andengine racing prevention means for increasing the fluid pressure supplied to the second element to prevent the engine racing when the engine racing is detected at an early stage of the upshift before an inertia phase of the upshift.