Hydraulic Control System for a Hydrodynamic Torque Converter Comprising a Controlled Torque Converter Lockup Clutch

A hydraulic control system (1A) for controlling a hydrodynamic torque converter (1) and a torque converter lockup clutch (2) of an automatic transmission, the control system comprising:

• a supply pressure (p_WD_zu) of the hydrodynamic torque converter (1), a supply pressure (p_WK_zu) of the torque converter lockup clutch (2), the torque converter lockup clutch (2) being engaged when the supply pressure (p_WD_zu) of the hydrodynamic torque converter (1) is smaller than a first predefined pressure level of the supply pressure (p_WK_zu) of the torque converter lockup clutch (2);
• a torque converter pressure valve (WDV) for controlling the supply pressure (p_WD_zu) of the torque converter (1) has a valve slide (WDV_S) which is acted upon by at least a pre-control pressure (p_VS) and a system pressure (p_sys);
• a torque converter clutch valve (WKV) for controlling the supply pressure (p_WK_zu) of the torque converter lockup clutch (2) has a valve slide (WKV_S) which is acted upon by at least the pre-control pressure (p_VS) and the system pressure (p_sys), the valve slide (WKV_S) of the torque converter clutch valve (WKV) has an active surface (15);
• and
• the active surface (15) of the valve slide (WKV_S) of the torque converter clutch valve (WKV) is acted upon, when the torque converter lockup clutch (2) is disengaged, by a reverse pressure (p_WD_ab) of the torque converter (1) and when the torque converter lockup clutch (2) is engaged, by the supply pressure (p_WK_zu) of the torque converter lockup clutch (2), such that over an entire operational area of the torque converter (1), one of the supply pressure (p_WD_zu) of the torque converter (1) and the supply pressure (p_WK_zu) of the torque converter lockup clutch (2) is greater than a prime predefined pressure level (p_0).