| The friction plate is an important vehicle part that plays a key role in the implementation of gear switching and power transmission.Currently,main techniques for tooth processing of large friction plates include wire electrical discharge machining and gear shaping.However,teeth processed using these techniques still require further strengthening to improve the fatigue resistance of the friction plate.Fine blanking is a processing technology developed on the basis of stamping.In the fine blanking process,parts are compressed by the V-ring,and cut by the combined action of a punch and a counter punch.During processing,the deformation zone is subjected to three-dimensional compressive stress and mostly remains under plastic deformation until the material is severed.Therefore,parts processed using fine blanking have smooth edges,small surface roughness,significant work hardening,and high residual compressive stress.Even without subsequent strengthening,fine blanked friction plates already have high residual resistance.According to the structure characteristics of the large friction plate,the fine blanking process of the large friction plate is studied using the finite element analysis method and experiment.First,based on the structural characteristics of the large friction plate and the fine blanking technology,a fine blanking model of the large friction plate is established.Given the friction layer on friction plate,a ‘convex reverse pressure plate’ and a ‘narrow side die’ structure were designed.The finite element analysis method was used to verify the feasibility of the large friction plate fine blanking scheme and to analyze the fine blanking forming process.Then,aiming at the dimension deviation problem caused by material anisotropy,numerical simulation and empirical testing was used to study the dimension deviation law of the large friction plate fine blanking forming process.The causation of the dimension deviation was analyzed,and the closed fine blanking process was developed to solve the problem.Lastly,a fine blanking experiment of large friction plates was designed to verify the numerical simulation results and to test the friction plate samples.The results show that the dimension deviation of the friction plate processed by the closed fine blanking die was reduced,and the dimensions met technical requirements.The teeth of friction plates had large plastic deformation and significant work hardening,and the teeth root had residual compressive stress.The results of the large friction plates fine blanking process above provide a reference for large parts fine blanking and expand the applicative range of fine blanking. |
