Discharge pressure scale and lifting-lowering device having a discharge pressure scale of this type

A lifting-lowering device, comprising:

• a hydraulic power cylinder;
• a proportional throttle valve performing a proportional flow regulating function connected to said hydraulic power cylinder;
• and
• a discharge pressure maintenance component connected at an output side of said proportional throttle valve, said discharge pressure maintenance component including a valve housing having a user port, a return port and a control port,
• a valve piston guided for longitudinal movement in said valve housing against a force of an energy store from an open position providing fluid communication between said user port and said return port to a closed position blocking fluid communication between said user port and said return port,
• a pressure compensator conveying fluid pressure at said user port to a pressure-effective surface of said valve piston such that said valve piston reaches the open position in a pressure-balanced manner due to the force of said energy store, said pressure compensator having a pressure compensation channel extending through said valve piston, said pressure compensation channel having a first free end opening in said valve housing in a direction of said user port and a second free end opening in an annular channel in said valve piston, said annular channel having said pressure-effective surface, and
• a valve seat in said valve housing with an inclined seat forming a tightly sealed leak-free stop for said valve piston with an included contact surface on said valve piston, said pressure-effective surface having a size equal to said inclined contact surface of said valve piston in an area of said valve seat, and being larger than a control surface at a free end face of said valve piston facing said user port due to an embossing process caused by movement of said valve piston and a geometric configuration of said valve seat.

A discharge pressure maintenance component, comprising:

• a valve housing having a user port, a return port and a control port;
• a valve piston guided for longitudinal movement in said valve housing against a force of a compression spring from an open position providing fluid communication between said user port and said return port to a closed position blocking fluid communication between said user port and said return port;
• a pressure compensator conveying fluid pressure at said user port to a pressure-effective surface of said valve piston such that said valve piston reaches the open position in a pressure-balanced manner due to the force of said compression spring;
• and
• a damping device being opposite said pressure compensator and including an antechamber closed by an orifice disk or throttle and opening into a spring chamber having said compression spring therein, said control port opening in said spring chamber in said valve housing, said antechamber opening into a damping chamber in said valve housing via said orifice or throttle of said damping device.