The Effects of Crack Propagation in the Production of Small Walled Blanks in Conventional Presses

Summary

Most approaches to manufacture of smooth edges in blanking and piercing are concerned with suppression of crack propagation. An earlier publication shows that, given suitable stress conditions, crack propagation can take place and a smooth edged component can still be effectively produced. (Patent Specification No. 1367639).

In this paper the edge profile resulting from the initial stage of crack propagation is examined for varying tooling conditions and the effects on both component and tooling characteristics are discussed.

The use of interchangeable testing equipment and the application of instrumentation is outlined. Also the relationship between the initial edge profile, associated tool geometry and the final form of the component is examined.

The proposed method can be directed at producing only isolated areas of smooth edges in order to reduce tool complexity and cost.

This implies that manufacturing engineers can evaluate the functional requirements of blankea components.