Issue 30

C.J.Su et alii, Frattura ed Integrità Strutturale, 30 (2014) 502-514; DOI: 10.3221/IGF-ESIS.30.61 509 Figure 9 : The relation of maximum contact pressure and punch in plate. Figure 10 : The effect of blanking quality by tooth depth. The impact of pitch on thick plate fine blanking The optimum parameter of upper tooth depth is 1.2 mm, and the simulation parameters of tooth pitch are shown in tab.3. Pitch(mm) Upper tooth depth(mm) Clearance(mm) 2.6 1.2 0.05 3.5 1.2 0.05 4.6 1.2 0.05 5.7 1.2 0.05 Table 3 : Simulation parameters of tooth pitch. Fig. 11 shows the hydrostatic pressure profiles of the different pitch circle of gear pressure style. We can learn from the numerical results that the position of ring gear also has an effect on the hydrostatic pressure, and the hydrostatic pressure decreases with the increasing of pitch. Therefore in the process of stamping sheet, appropriate pitch should be chosen to ensure the sufficient hydrostatic pressure blanking, and to fully improve the plastic sheet to obtain the ideal blanking section. Fig. 12 shows that, in different pitches, the materials stress distribution of the punch downward 1/6. Before the start of the blanking, the shear zone produced a certain value of hydrostatic pressure, creates a better plastic state for the further deformation of material. In the graph, as the pitch increases and compressive stress area reduces deformation, the shear zone compressive stress becomes larger, but stress is smaller far away from the area of fine blanking parts of the compressive.