METHOD FOR AUTOMATICALLY CONTROLLING AN ELECTROHYDRAULIC PRESSING TOOL

摘要

In the case of a method for automatically controlling an electrohydraulic pressing tool, in particular for producing pipe connections, to actuate the pressing tool a hydraulic piston (10) is moved, in that fluid is pumped into a hydraulic cylinder (12) by a hydraulic pump (14) driven by means of an electric motor (26). When a limiting pressure in the hydraulic cylinder (12) is reached, a pressure relief valve (32) opens, and so the hydraulic fluid can flow into a reservoir (16). With the aid of a control device (30), a current drop at the motor (26) is detected when the valve (32) opens. The electric motor (26) is switched off when the current falls by a predetermined value (?I) and/or decreases over a predetermined time period (?t) after reaching a limiting current.