A major problem in the aircraft piston engine development is time to market. At first the initial design is tested and a first prototypical batch is manufactured. In this phase the use of “soft tooling” is compulsory, since the “hard tools” of serial production are unsuitable for the several changes necessary during the development phase. Then the “hard tooling” phase takes place. Even with virtual prototyping, several problems arise during the manufacturing process of cast components, where important technological constraints impose modification of the original, strictly functional, CAD model. In this field a new technique of modelling, prototyping and manufacturing is introduced in this paper. A very simple two axis CNC machine is used to manufacture a polystyrene foam model of the cast parts. Then the lost foam technique is used to obtain high quality cast parts, a resin mould for sand casting or the metal dies. This technique makes it possible to obtain immediately a physical 3D mock-up of the part, which can be directly taken in the foundry or can be used in the design office and in the prototype shop to check for correct design. Moreover the CAD phase is constrained by the limitation of this technique, so the design & simulation time is also greatly reduced by this simultaneous engineering process. Modifications and improvements are easily implemented. This 2D sections-lost foam technique can be used also for serial production. In this case also several advantages are obtained. Wood, metal or plastic model are not necessary for sand casting, client specific design may be easily implemented without changing the manufacturing line and difficult shapes, impossible for traditional techniques, are easily implemented. The method is convenient for serial production up to 300 pieces per year with Italian labour costs. For more numerous productions other techniques should be used. However, also in this case, the foam model is useful for the final design of high-number production tools.
Francia D., Piancastelli L., Renzi C. (2008). RAPID DESIGN, RAPID PROTOTYPING & RAPID MANUFACTURING (RPDM): AN APPLICATION OF AN INNOVATIVE TECHNIQUE ON AIRCRAFT PISTON ENGINE. VALENCIA : s.n.
RAPID DESIGN, RAPID PROTOTYPING & RAPID MANUFACTURING (RPDM): AN APPLICATION OF AN INNOVATIVE TECHNIQUE ON AIRCRAFT PISTON ENGINE
FRANCIA, DANIELA;PIANCASTELLI, LUCA;RENZI, CRISTINA
2008
Abstract
A major problem in the aircraft piston engine development is time to market. At first the initial design is tested and a first prototypical batch is manufactured. In this phase the use of “soft tooling” is compulsory, since the “hard tools” of serial production are unsuitable for the several changes necessary during the development phase. Then the “hard tooling” phase takes place. Even with virtual prototyping, several problems arise during the manufacturing process of cast components, where important technological constraints impose modification of the original, strictly functional, CAD model. In this field a new technique of modelling, prototyping and manufacturing is introduced in this paper. A very simple two axis CNC machine is used to manufacture a polystyrene foam model of the cast parts. Then the lost foam technique is used to obtain high quality cast parts, a resin mould for sand casting or the metal dies. This technique makes it possible to obtain immediately a physical 3D mock-up of the part, which can be directly taken in the foundry or can be used in the design office and in the prototype shop to check for correct design. Moreover the CAD phase is constrained by the limitation of this technique, so the design & simulation time is also greatly reduced by this simultaneous engineering process. Modifications and improvements are easily implemented. This 2D sections-lost foam technique can be used also for serial production. In this case also several advantages are obtained. Wood, metal or plastic model are not necessary for sand casting, client specific design may be easily implemented without changing the manufacturing line and difficult shapes, impossible for traditional techniques, are easily implemented. The method is convenient for serial production up to 300 pieces per year with Italian labour costs. For more numerous productions other techniques should be used. However, also in this case, the foam model is useful for the final design of high-number production tools.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
