Patent ID: 7975566

Claim:
A hydraulic control apparatus for an automatic dual clutch transmission, comprising: a first clutch with a first partial transmission and a second clutch with a second partial transmission, as well as a shifting system for engaging/disengaging gears of the two partial transmissions, a control unit that controls at least one of the parameters controllable pressure and controllable volumetric flow for the actuation of the first and second clutches and for the actuation of the shifting system, a switching apparatus that is arranged between the control unit and the clutches or the shifting system and can be used to switch the at least one of the parameters controllable pressure and controllable volumetric flow between the clutches or the shifting system, the control unit having a first pressure regulator and a second pressure regulator, wherein the shifting apparatus comprises: a first changeover valve that a) in a first position (A I ) connects the first pressure regulator to the first clutch and disconnects the first pressure regulator from the shifting system, and b) in a second position (B I ) connects the first pressure regulator to the shifting system and disconnects the first pressure regulator from the first clutch; and a second changeover valve that c) in a first position (A II ) connects the second pressure regulator to the second clutch and disconnects second pressure regulator from the shifting system, and d) in a second position (B II ) connects the second pressure regulator to the shifting system and disconnects second pressure regulator from the second clutch, wherein in the second position (B I ) of the first changeover valve and in the second position (B II ) of the second changeover valve a connection is established between the second changeover valve and the first clutch while the second clutch is substantially completely depressurized.