Studies, Researches and Development Prospects on The Quality of Metal Products Made on CNC Machines

Neta PUSCAS (POPESCU)

The paper presents studies and researches in the field of bending of metal parts (thickness between 1 and 3 mm) on CNC machines. This paper tries to provide answers to the many problems arising in the companies due to the quality of the economic goods. The paper proposes laborious research and studies on determining the drawings of metal parts with the thickness g=1.5 mm, considering that other variables such: the temperature variation during the processes of punching and bending, tool usage, the tolerance between the surfaces of the bending tools, the vibrations of the machines, their usage and the roughness of the sheet metals may influence the quality and precision of the products. The calculation of the drawing (the geometry in plane of the piece) becomes important because it must include the deformation caused by the bending operation. Bending coefficients K_î  must compensate for deviations from the final dimentions of the metal parts, because of the many variables that can adversely affect their execution. During the study we obtained the bending coefficients for the components made out of metal sheet OL 37 with 1.5 mm thickness. The bending coefficient K_î is determined by experimental tests and measurements, depending on the material thickness, chemical composition, its quality, bending complexity, the movement between the surfaces of punching and bending tools, vibration of the machines, their usage, the roughness of the sheets metal as a result of lamination process and other variables that may influence the quality and precision of the products.