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, including the method steps:

• providing 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;
• predetermining by means of said control unit at least one of controllable pressure and controllable volumetric flow for the actuation of the first and second clutches and for the actuation of the shifting system, and
• providing a switching apparatus that is arranged between the control unit and the clutches and the control unit and the shifting system and can be used to switch the controllable pressure or the controllable volumetric flow onto the clutches or the shifting system, the control unit having a first pressure regulator and a second pressure regulator, and the switching apparratus having a first switching valve and a second switching valve,
• operating the first switching valve so that the first switching valve
• a) in a first position (AI) 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 (BI) connects the first pressure regulator to the shifting system and disconnects the first pressure regulator from the first clutch;
• and
• operating the second switching valve so that the second switching valve
• c) in a first position (AII) connects the second pressure regulator to the second clutch and disconnects the second pressure regulator from the shifting system, and
• d) in a second position (BII) connects the second
• pressure regulator to the shifting system and
• disconnects the second pressure regulator from the second clutch,
• setting the pressure of the pressure regulator prior to switching the first switching valve from second position (BI) to the first position (AI) or prior to switching the second switching valve from the second position (BII) to the first position (AII) to a value which depends on the subsequent actuation of the clutch that is acted on by the pressure of the pressure regulator after the first switching valve has been switched to the first position (AI) and the second switching valve has been switched to the first position (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 of controllable pressure and 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 that is arranged between the control unit and the clutches and the control unit and the shifting system and can be used to switch the controllable pressure or the controllable volumetric flow onto the clutches or the shifting system, the control unit having a first pressure regulator and a second pressure regulator, and the switching apparatus 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;
• the first switching valve has a first position (AI) and a second position (BI) and the second switching valve has a first position (AII) and a second position (BII);
• a) in the first position (AII) of the second switching valve, said second switching valve produces a connection, via the inlet and the outlet, between the second pressure regulator and the second clutch;
• b) in the second position (BII) of the second switching valve, the second pressure regulator and a 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, and 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 first switching valve;
• c) in a first position (BI) of the first switching valve pressure is applied to the first clutch by the second pressure regulator;
• d) in the second position (BI) of the first switching valve and the second position (BII) of the second switching valve the second clutch is actuated with the first pressure regulator since a further line connects the two switching valves;
• e) in the first position (AI) of the first pressure regulator a preset pressure is applied to the first clutch.