Renault: Over 520 More Parts per Hour
Renault needed to define design rules for the filling and feeding systems for casting processes on different product lines in order to enhance competitiveness and achieve high quality production. Using ESI QuikCAST, part of ESI’s casting solution, Renault was able to enhance competitiveness, reduce development time and cost and improve product quality.
Renault has made a considerable investment in a new molding line at Fonderie de Bretagne (FDB). They standardized their production methodologies and used simulation early in the development cycle. This meant devising a standard for creating molding layout and feeding design that could be replicated across a wide range of casting products. The pilot project was an existing 6-cavity mold layout of a cast iron knuckle; one already in production but experiencing noticeable shrinkage porosity problems.
Using ESI QuikCAST simulation software, they performed a single casting simulation with no filling or feeding system, observing the solidification in the sand mold, with a starting temperature close to the pouring temperature. The natural thermal gradients of the casting were used to identify the solidification path and pinpoint the last solidifying regions in the casting.
“After using ESI QuikCAST, not only were we able to increase our bottom line by saving on metal and creating more castings than before, but we also implemented a completely new system for casting that we now use routinely across various product lines within the company,” tells Laurent Soulat, Casting Specialist at Renault Process Engineering
Next, they created various practical feeding designs and performed a complete simulation to identify the one leading to the best solidification pattern and without signs of shrinkage porosity in the casting. Having identified a suitable feeder, a similar exercise was repeated with multiple gating options.
Finally they expanded this optimized single-cavity design into a multiple-cavity mold. Renault improved the knuckle mold from a 6-cavity 97kg to an 8-cavity 82kg cluster. The new design solved the shrinkage problem and provided a yield improvement; saving 37% in metal for every part produced and it produced two additional parts per mold, delivering over 520 additional parts per hour. The cost savings was substantial.
Thanks to the ESI QuikCAST, Renault resumed production of the Spheroidal Graphite Iron “Renault Traffic Front Knuckle” and now uses this methodology successfully across different product families.