OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 6 No. 2 2024 Fig. 3. Press tool for cold die forging: 1 – rod; 2, 6 – upper and lower punches; 3 – floating die; 4 – internal (spherical) bearing of the hinge unit; 5 – powder blank; 7 – fixing lower punch The QForm program allows not only to establish the dependence of strain resistance and evaluate the work of active forces, but also to simulate the process of cold forming of a porous blank at any moment of time. As an example, (Fig. 5) shows the density distribution, stress field and accumulated (effective) deformation at different values of εz. After the pressure is removed during cold forming, the bearing outer ring is tightly seated in the forming seat of the matrix as a result of elastic aftereffects (Fig. 3). Therefore, a certain force is required to push it out of the matrix, which depends on the initial and residual porosity of the ring, the specific work of cold deformation, the characteristics of lubricants, etc. In this case, the outer diameter of the outer ring of the bearing after ejection increased by about 0.03 mm relative to the diameter of the matrix, and the radial increase in the inner diameter of the ring as a result of elastic aftereffect was about 0.01 mm, which is sufficient in the presence of lubricant for free rotation of the inner ring relative to the outer ring. a b Fig. 4. Influence of relative strain of the porous blank on the strain resistance depending on the chamfer angle αch at the end of the upper and lower punches, deg: 1 = 0; 2 = 10; 3 = 20; 4 = 30; 5 = 40; 6 = 50
RkJQdWJsaXNoZXIy MTk0ODM1