Tube expander which measures variable effort applied to rolling tool - simultaneously with a linear variable of the expanding operation

摘要

Tubes are expanded into a tube wall using a roller-type rolling tool and the variable effort applied to the tool is measured simultaneously with a linear variable of the expanding operations over three successive stages affected by the expansion. The stages comprise the area of elastic deformation of the tube work, the are of plastic deformation of the tube up to the moment of tube/tube wall engagement, and the area of elastic deformation of the tube wall. Control over the expanding operation is optimised by processing the measured data in accordance with the dimensions and mechanical properties of the tube and tube wall materials. The strength and fluid tightness of each rolling joint are improved which results in longer life of structures so assembled. Used in the assembly of heat exchangers and steam generators.