REFERENCES
109
REFERENCES
1. Vinarcik, E., ‘‘Finite Element Analysis of Process Data Curves for Statistical Process Control,’’ SAE Paper Number 970081, Society of Automotive En-
gineers, Warrendale, PA, 1997. 2. Roshan, H., V. Sastri, and R. Agarwal, ‘‘Die Temperature Control in Pressure
Die Casting,’’ AFS Transactions, American Foundrymen’s Society, Des Plaines, IL, 1991, p. 493.
DESIGN CONSIDERATIONS FOR HIGH INTEGRITY
DIE CASTINGS
113
7
DESIGN FOR MANUFACTURABILITY
OF HIGH INTEGRITY DIE CASTINGS
7.1 INTRODUCTION TO DESIGN FOR
MANUFACTURABILITY
Product cost, manufacturability, and quality are intimately related to product design. A skilled manufacturer may be able to reduce
scrap and optimize a process to achieve near-ideal efficiency, but the cost and quality of a product can never be improved further
without changing the design. Major reductions in product cost can only be attained through discerning design work.
All manufacturing methods have limitations, high integrity die casting processes included. Skilled designers and product engi-
neers will adjust and refine designs to take advantage of the production process chosen. This is known as design for manu-
facturability.
7.2 HIGH INTEGRITY DIE CASTING DESIGN FOR
MANUFACTURABILITY GUIDELINES
Although high integrity die casting processes may be able to pro- duce products that cannot be manufactured using conventional die
casting methods, the same design for manufacturability guidelines
114
MANUFACTURABILITY OF HIGH INTEGRITY DIE CASTINGS
Figure 7.1 Production fuel rails Z-1 top and Z-2 bottom.
apply for optimizing product geometry. This criterion is well doc- umented and includes the following design considerations:
1. maintaining a consistent wall thickness; 2. using gradual transitions from surface to surface;
3. eliminating large metal masses; 4. using comers, fillets, and radii to assist with metal flow;
5. using ribs to facilitate metal flow; and 6. maintaining a sufficient draft angle.
1,2
By following these six general guidelines, the majority of manu- facturing problems caused by the design can be avoided.
7.3 AUTOMOTIVE FUEL RAIL CASE STUDY REVIEW
The purpose of this case study is to review the designs of two fuel rails manufactured using the semi-solid metalworking process
shown in Figure 7.1. For discussion purposes, the fuel rails will be designated Z-1 top and Z-2 bottom. Both fuel rails are in-
tended for use in four-cylinder engines of equal size. After intro-
