Patent ID: 8528712
Filing Date: 2013-09-10
Classification: F16H,Y10T

Abstract:
1. An automatic transmission hydraulic control apparatus comprising: six friction elements of which two friction elements operate to achieve a stage by means of hydraulic pressure; five direct-controlled solenoid valves that individually and directly control hydraulic pressure that is supplied to four friction elements in the six friction elements and equally and directly control hydraulic pressure that is supplied to two friction elements; an on-off solenoid valve that converts output state and non-output state of hydraulic pressure; a switch valve in which one side of a valve spool is provided with a spring and which selectively supplies hydraulic pressure from one of the direct-controlled solenoid valves, which equally and directly control the hydraulic pressure, in accordance with whether hydraulic pressure from the on-off solenoid valve is applied to the other side thereof; and four fail-safe valves that are disposed between the direct-controlled solenoid valves and the six friction elements to structurally limit available arrangements of the six friction elements.