HYDRAULIC CONTROL DEVICE FOR AUTOMATIC TRANSMISSION

摘要

PURPOSE:To perform smooth simultaneous switching of one brake and a plurality of other engaging elements by controlling a differential pressure between a pressure for engaging a first engaging device and a pressure for engaging a second or a third engaging device. CONSTITUTION:A control device simultaneously controls a first brake 21 being a first engaging device, a second clutch 12 being a second engaging device, and a third clutch 13 being a third engaging device. The control device is provided with a control means for a pressure difference communicated to the hydraulic servo of the first engaging device and a release relay valve 330 of a first brake 21 being a switching means selectively communicating a hydraulic servo 12S of the second engaging device or a hydraulic servo 13S of the third engaging device with a control means for a pressure difference. The control means for a pressure difference comprises feed chambers 21A and 21B and release chamber 21R of the first brake 21 and a linear solenoid valve 46 to control an oil pressure to the oil chamber.