Abstract
The article presents the results of theoretical and experimental studies of the process of two-support plastic bending. The process of deforming a round-section blank that was located on two fixed supports and deformed by a punch with a cylindrical working surface was considered. The punch was located in the middle between the supports and moved perpendicular to the longitudinal axis of the undeformed workpiece. Using the software package "Mathcad", the analytical dependence of the bending angle on the stroke of the punch and the corresponding dimensions of the workpiece and tool is established. The "Deform-3D" software package was used for computer modeling of the two-support bending process. The hardening curve of calibrated 40С2А steel used in the calculations was based on the results of compression tests of samples with end flanges. The calculations varied the geometric parameters of the bending process: the diameter of the workpiece 11.0÷17.0 mm, the radius of the working surface of the punch 15.0÷20.0 mm, the radius of the supports 15.0÷20.0 mm and the distance between the axes of the supports 90.0÷100.0 mm. It is established that in the process of two-support plastic bending of a rod blank, a zone of contact loss occurs between the deformed blank and the tool, that is, a non-contact zone is formed. Experiments on plastic bending of workpieces with a diameter of 11.0 mm made of 40С2А steel using a universal testing machine ИР 5082-100 and the corresponding equipment confirmed the formation of a non-contact zone. To summarize the results of the study introduced the relative maximum height of the Central angle and non-contact zones and plotted these parameters from bending angle, the size of the workpiece and the bending tool.
Keywords
Plastic two-tools bending process, finite element modeling, round bar, non-contact zone, bending angle, bending tool.