A quantitative planning method of variable feed rates for cold profiled ring rolling process

Cold profiled ring rolling (CPRR) is an advanced local incremental forming process with complexity and high nonlinearity. In this process, the feed rate of mandrel is a key factor affecting the expanding speed of ring outer radius and the filling behavior; thus, it is very significant to rationally design the feed rate for precise controlling the deformation process. Aimed at the CPRR process, the problem of feed rate planning under two variable feed patterns, which are constant expanding speed of ring outer radius (P CES) and constant feed amount per ring revolution (P CFA), has been solved successfully by using the hypothesis-testing approach in this paper. First, according to the relation between the ring outer radius R and the ring reduction ΔH, a novel mathematical solution for planning the feed rates under P CES and P CFA has been proposed, in which a series of points of (R, ΔH) under constant feed rate (P CFR) pattern have been taken into consideration. Second, two differential equations obtaining variable feed rate curves under P CES and P CFA have been built and their solving processes have also been given, and subsequently a new quantitative planning flow of variable feed rates has been presented. Third, an example of three feed rates planning under P CFR, P CES, and P CFA for a practical closed cold T-shaped ring rolling process in the design phase has been realized, and their validity has been proven by three-dimensional finite element numerical simulation. The achievements can provide a guideline for planning the feed rates of the relevant complex profiled ring rolling processes to improve efficiency and reduce cost.