Method and Device for Filling a Hydraulic System with a Hydraulic Fluid

A method for filling a hydraulic system (SYS) with a hydraulic fluid (40), comprising the steps of:

• sealing the hydraulic system (SYS) in a pressure-tight manner and recording a pressure (p2, abs) in the sealed hydraulic system (SYS);
• filling or removing a predefined second volume (ΔVKM, Mess) of the hydraulic fluid (40) from the sealed hydraulic system (SYS);
• recording a pressure (p3, abs) in the sealed hydraulic system (SYS) after the filling or removing of the predefined the second volume (ΔVKM, Mess);
• calculating a volume (V3) of a total residual air in the hydraulic system (SYS) depending on the pressures (p2, abs, p3, abs) before and after the filling or removal of the predefined second volume (ΔVKM, Mess) and calculating a final correction volume (VKM, korr) depending on the volume (V3) and a design-specified air feed (VL, AGB) of the hydraulic system (SYS);
• and
• refilling or removing the calculated final correction volume (VKM, Korr) to achieve a final correct filling quantity for the hydraulic system (SYS).

A method for filling a hydraulic system (SYS) with a hydraulic fluid (40), comprising the steps of:

• sealing the hydraulic system (SYS) in a pressure-tight manner and recording a pressure (p2, abs) in the sealed hydraulic system (SYS);
• filling or removing the hydraulic fluid (40) from the sealed hydraulic system (SYS) until a predefined pressure (p3, abs) is reached in the sealed hydraulic system (SYS) and recording a volume (ΔVKM, Mess) of the hydraulic fluid (40) filled in during the filling or removing;
• calculating a volume (V3) of a total residual air in the hydraulic system (SYS) depending on the pressures (p2, abs, p3, abs) before and after filling or removing of a second volume (ΔVKM, Mess) and calculating a final correction volume (VKM,korr) depending on the volume (V3) and a design-specified air feed (VL, AGB) of the hydraulic system (SYS);
• and
• refilling or removing the calculated final correction volume (VKM, Korr) to achieve a final correct filling quantity for the hydraulic system (SYS).

A device for filling a hydraulic system (SYS), comprising:

• a filling adapter (42);
• a line (13) for hydraulic fluid (40);
• a pressure sensor;
• a means for closing the hydraulic system (SYS);
• and
• a control unit (ECU).