RAPID  PRODUCT  DEVELOPMENT

This case study is on the rapid development of an inlet manifold for an engine at FIAT. It reflects the impact of RP on new design procedures for enterprise competitive advantage in terms of cost and time reduction and final quality of a new product. The main value of RP approach comes out from its complete integration with CAD. In other words, CAD and RP are at the core of the Rapid Product Development.

Due to the complexity of the inlet manifold, the conventional design procedure is rather time-consuming and several design phases must be accomplished. The starting point is the design of the manifold with traditional methods. In this case a sound design depends on the skill and proficiency of the designer. First, the approximate shape of the manifold as a flow-box is obtained by machining. The flow-box is used to verify if the channel geometry optimizes the engine performance. It may require further modifications to tune the efficiency. Subsequently, the foundry experts design the preliminary foundry tooling for the sand mould of the aluminum prototype. The cast prototype requires further machining to meet the dimensional and roughness specifications. The inlet manifold then undergoes bench-tests. When it is successful in these tests, the construction of final casting mould for the new inlet manifold can start. The average time to complete the whole procedure is nearly six months.

In FIAT, the new inlet manifold was designed since the beginning of the product development phase with CAD. This electronic model allowed the virtual simulation of the component through CAE tools. In this way the first results on flow distribution were obtained in a few days. Then the first prototype was made out of regular nylon with using Sinterstation 2000, a SLS RP machine from DTM. This prototype had adequate strength, thermal  stability and surface finish for functional testing directly on the engine. Before mounting the inlet manifold on the engine, the part was infiltrated with resin to make it impervious to gases. At the end of this testing, the foundry experts designed the final casting mould for production. The whole procedure took only a month.

            According to FIAT, the cost of developing this inlet manifold reduced to a 10^th when RPD was used, i.e., it came down from 150,000US$ to 15,000USD. They could also compress the time to a 6^th, i.e., it came down from 6 months to one month.