System for braking a displacement-controlled drive system

A system for braking a hydraulic working cylinder which is configured to be driven, for a motion of a piston rod of the hydraulic working cylinder, connectable to a load, in two opposite directions, separating a first utility port of the hydraulic working cylinder from a second utility port of the hydraulic working cylinder connectable to a pressure source and a tank port or a return port, the system comprising:

• logic valves;
• and
• electro-proportionally actuatable control valves,
• wherein:
• the system is configured to control, by an electro-proportional adjustment of one of the logic valves, an outflow volume flow of the hydraulic working cylinder such that an outflow pressure is decoupled from the motion of the piston rod of the hydraulic working cylinder and coupled to an inflow pressure so as to lower the inflow pressure for a motion of the hydraulic working cylinder;
• the logic valves are configured to determine, depending on a direction of the motion of the piston rod of the hydraulic working cylinder, the outflow pressure at the first utility port of the hydraulic working cylinder or the outflow pressure at the second utility port the hydraulic working cylinder;
• the logic valves are configured to be spring closed and electrically unlocked;
• the logic valves are configured to close seat-sealingly;
• and
• the system is further configured to:
• (i) for electrical unlocking, have at least a control pressure of one of the electro-proportionally actuatable control valves act on a first control end of the one of the logic valves;
• (ii) control, on a second control end of the one of the logic valves, a fluid connection between the first utility port of the hydraulic working cylinder or the second utility port of the hydraulic working cylinder and the tank port or the return port;
• and
• (iii) connect the pressure source to one of the first of the hydraulic working cylinder or the second utility port of the hydraulic working cylinder by bypassing the other of the logic valves, which is held in a spring closed position.