SPEED CHANGE CONTROL DEVICE OF AUTOMATIC TRANSMISSION

摘要

PURPOSE:To prevent no-load stamping by allowing a specific high speed position in the condition with engaging pressure supplied to once pass through the apply chamber of an actuator for brake means when the line oil pressure is low at shifting-down from the specific high speed position. CONSTITUTION:In a speed change control circuit 200, a 3-4 clutch 27 makes shifting-down from engagement to disengagement while a 2-4 brake 23 from disengagement to engagement. If the line pressure in hydraulic control circuit is low at the time of shifting down from the fourth speed in the condition that the engaging pressure is exhausted from the apply chamber 23d of an actuator 23c of this 2-4 brake 23, shifting down into a specific low speed position is made after passing through specific high speed position in the condition that the engaging pressure is supplied into the apply chamber 23d. Thus correction is made to the tendency that oil pressure supply to the apply chamber is delayed when the line pressure is low to lead to prevention of the engine from no-load operation resulting from delay.