Patent ID: 8715138

Claim:
A hydraulic control device for a speed change device capable of transferring power applied to an input member to an output member at a speed change ratio that is changeable in a plurality of stages by engaging and disengaging a plurality of hydraulic friction engagement elements, the hydraulic control device comprising: a first pressure regulation valve that regulates a hydraulic pressure to be supplied to a first hydraulic friction engagement element; a second pressure regulation valve that regulates a hydraulic pressure to be supplied to a second hydraulic friction engagement element that is normally not engaged at the same time as the first hydraulic friction engagement element; and a switching valve that can establish a blocked/discharge state, in which supply of the hydraulic pressure from the second pressure regulation valve to the second hydraulic friction engagement element is blocked and a hydraulic pressure can be discharged from the second hydraulic friction engagement element, and a communicated state, in which the hydraulic pressure from the second pressure regulation valve can be supplied to the second hydraulic friction engagement element, and that can receive a signal pressure for establishing the blocked/discharge state and the communicated state and the hydraulic pressure from the first pressure regulation valve, wherein the switching valve is supplied with a first signal pressure as the signal pressure when the blocked/discharge state is established and supplied with a second signal pressure, which is lower than the first signal pressure, as the signal pressure when the communicated state is established, and the switching valve establishes the blocked/discharge state when the hydraulic pressure from the first pressure regulation valve is input in the communicated state.