Hydraulisk kran med registrering av lyftning och/eller nedsättning av last, förfarande för sådan registrering samt förfarande för beräkning av utmattningsbelastningen hos en hydraulisk kran

摘要

A hydraulic crane (1) comprising a liftable and lowerable crane boom (5), a hydraulic cylinder (8) for lifting and lowering the crane boom (5) and registration means (35) adapted to register lifting up or putting down of a load in dependence on the rate of the changes in the cylinder force (F c ) of the hydraulic cylinder (8). The registration means (35) is adapted to register that the crane executes a lifting up or putting down of a load when the rate of a detected change in the cylinder force (F c ) exceeds a predetermined value. The invention also relates to the method for registration of lifting up or putting down of a load by a hydraulic crane, and a method for calculating the fatigue stressing of a hydraulic crane based on the registered number of liftings up and/or puttings down of load.