Hydraulic control apparatus for an automatic dual clutch transmission

A method for controlling a dual clutch transmission using a hydraulic control apparatus for an automatic dual clutch transmission, which includes first clutch with a first partial transmission and a second clutch with a second partial transmission, as well as a shifting system for engaging/releasing gears of the two partial transmissions, having a control unit which predetermines at least one controllable pressure and/or at least one controllable volumetric flow for the actuation of the first and second clutches and for the actuation of the shifting system, and having a switching apparatus, which is arranged between the control unit and the clutches or the shifting system and can be used to switch the controllable pressure or the controllable volumetric flow between the clutches or the shifting system, the control unit having a first pressure regulator and a second pressure regulator, and the switching device having a first switching valve and a second switching valve, wherein

• the first switching valve
• a) in a first position AI connects the first pressure regulator to the first clutch and disconnects it from the shifting system, and
• b) in a position BI connects the first pressure regulator to the shifting system and disconnects it from the first clutch;
• and
• the second switching valve
• c) in a position AII connects the second pressure regulator to the second clutch and disconnects it from the shifting system, and
• d) in a position BII connects the second pressure regulator to the shifting system and disconnects it from the second clutch,
• wherein the method comprises the method step that prior to switching from position BI, BII to position AI, AII of the first or second switching valves, the pressure of the pressure regulator is set to a value which depends on the subsequent actuation of the clutch which is acted on by the pressure of the pressure regulator after the switching valve has been switched to position AI, AII.

A hydraulic control apparatus for an automatic dual clutch transmission, which includes 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/releasing gears of the two partial transmissions, having a control unit which predetermines at least one controllable pressure and/or at least one controllable volumetric flow for the actuation of the first and second clutches and for the actuation of the shifting system, and having a switching apparatus, which is arranged between the control unit and the clutches or the shifting system and can be used to switch the controllable pressure or the controllable volumetric flow between the clutches or the shifting system, the control unit having a first pressure regulator and a second pressure regulator, and the switching device having a first switching valve and a second switching valve, wherein

• the first switching valve and also the second switching valve are designed as structurally identical 9/2-way switching valve with three outlets and six inlets to;
• the switching valve has two positions AI, BI and the switching valve has two position AII, BII;
• a) in position AII the switching valve produces a connection, via the inlet and the outlet, between the second pressure regulator and the second clutch.
• b) In position BII, the second pressure regulator and the pressure switching means are connected to one another via the inlet and the outlet, thereby providing the possibility of pressure regulation for shifting of the gears while at the same time, a connection is produced between the second pressure regulator and a line leading to the first switching valve, via the inlet and the outlet, and the line is connected to the inlet of the first switching valve and, via the outlet of the latter
• c) In position BI of the first switching valve pressure is applied to the first clutch by the second pressure regulator.
• d) In positions BI, BII of the two switching valves the second clutch is actuated with the first pressure regulator since a further line connects the two switching valves;
• e) In position AI of the first pressure regulator a preset pressure is applied to the first clutch.