Design and optimization of multi‑stage manufacturing process of stirling engine crankshaft

摘要

Crankshafts are among the most important parts in internal combustion engines, of which stirling engine is a usefulexample. Manufacturing process of a crankshaft, is considered as a three-step forging process using preform, due to thecomplexity in geometry. The most challenging step of the multistage forging process is to avoid stress concentrationand to create uniformity of strain by controlling metal flow. In the present study, the final part was achieved under threemanufacturing processes namely: upsetting, hot and cold forging. The models used in each manufacturing process aredesigned by CATIA software. A finite element simulation on the basis of Cockcraft–Latham damage criterion was developedin DEFORM software. Using experiment design by Taguchi method, The optimization of manufacturing processeswere carried out by MINITAB software in two steps, in which the optimization objectives are considered as force, damageand strain uniformity, and; input variables are taken as part-mold friction, pressing velocity and process temperature.In order to find the most effective parameter of each manufacturing process, analysis of variance was conducted onthe results, in which, the most effective parameters in the upsetting, hot and cold forging processes were temperature,friction and temperature, respectively.