Hydraulic control apparatus of an automated multi-step change-speed gearbox

A hydraulic control device of an automated multi-step transmission, the control device comprising:

• a plurality of gear-actuating cylinders (Z1-Z4) for engaging and disengaging gears of the multi-step transmission;
• at least two pressure-controlled gear-regulating valves (GV1-GV3) for controlling an operating pressure of one pressure chamber (D1-D8) of the gear-actuating cylinders (Z1-Z4);
• a multiplex arrangement (2, 102) of a plurality of singly switchable pressure-controlled selector valves (WV1-WV3) for assigning the gear-regulating valves (GV1-GV3) to one pressure chamber (D1-D8) of the gear-actuating cylinders (Z1-Z4);
• at least one common pilot valve (VV1-VV3) for actuating one of the gear-regulating valves (GV1-GV2) and at least one of the selector valves (WV1-WV3);
• the pilot valve (VV1-VV3) having a first control pressure range (ΔP_B1) containing a switching pressure (P_S) of the at least one selector valve (WV1-WV3) and a second control pressure range (ΔP_B2) containing a regulating range (ΔP_R) of the gear-regulating valve (GV1-GV3);
• the gear-regulating valve (GV1-GV3) and the at least one selector valve (WV1-WV3), which are controllable by the common pilot valve (VV1-VV3), being assigned to one of different actuating rods and a different partial transmission;
• and
• the multi-step transmission has four actuating rods, a shifting arrangement with three gear-regulating valves (GV1-GV3), three selector valves (WV1-WV3), and three pilot valves (VV1-VV3), by which, via a first selector valve (WV1), an operating pressure line (113) of a first gear-regulating valve (GV1) and an operating pressure line (123) of a second gear-regulating valve (GV2) are alternately connected to an assigned pressure chamber (D1, D2) or an interconnecting line (146;
• 149) that leads, in each case, to another selector valve (WV2, WV3), by which, via a second selector valve (WV2), the interconnecting line from the first selector valve (WV1) is alternately connectable to two different pressure chambers (D3, D5) and, via a third selector valve (WV3), an operating pressure line (133) of a third gear-regulating valve (GV3) and the interconnecting line (149) of the first selector valve (WV1), are alternately connectable to two different pressure chambers (D6, D8;
• D4, D7), one control pressure chamber (111) of the first gear-regulating valve (GV1) and one switching pressure chamber (163) of the third selector valve (WV3) are connected to a control terminal (106) of a common first pilot valve (VV1), one control pressure chamber (121) of the second gear-regulating valve (GV2) and one switching pressure chamber (153) of the second selector valve (WV2) is connected to a control terminal (116) of a common second pilot valve (VV1), and one control pressure chamber (131) of the third gear-regulating valve (GV3) and one switching pressure chamber (143) of the first selector valve (WV1) is connected to a control terminal (106) of a common third pilot valve (VV3).