Pressed Blank Edge Cutting for Stretch Flange Crack Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing pressed components with stretch flange deformation fail to effectively prevent edge cracks while maintaining the freedom of the component shape, as they either constrain the shape or have limited effectiveness.
Innovation Solution
A two-stage cutting process is applied to the edges of the component where edge cracks are predicted, forming a partial, beam-shaped overhang portion in the first cut and then cutting it off in the second cut, to mitigate strain and prevent edge cracks during press forming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional single cutting method is used, then manufacturing process is simple, but edge cracks occur due to stretch flange deformation
Solution Approach 1:
The cutting process is divided into two distinct stages: first cutting creates a partial overhang portion, and second cutting removes it. This segmentation allows the edge to be prepared in a way that prevents stretch flange deformation and edge cracks, while maintaining manufacturing feasibility through standardized cutting operations.
Solution Approach 2:
The first cutting creates a partial overhang portion as a preliminary structure before the final cutting is performed. This overhang portion serves as a pre-prepared feature that prevents edge cracks during subsequent press forming operations, eliminating the need for complex edge treatments later.
2Reliability
If blank shape is constrained to prevent stretch flange crack, then edge crack is prevented, but degree of freedom of product shape is constrained
Solution Approach 1:
The two-stage cutting method applies a localized treatment (creating and removing partial overhang portion) only at specific edges where stretch flange deformation and edge cracks are predicted to occur. This local intervention prevents edge cracks without imposing global constraints on the blank shape, thereby maintaining design freedom for the overall product geometry.
3Reliability
If excess thickness is provided by press die, then edge crack is suppressed, but manufacturing flexibility is reduced
Solution Approach 1:
The partial overhang portion is created as a preliminary structural feature through the first cutting operation, which prevents edge cracks by modifying the stress distribution at the edge before press forming. This approach provides crack prevention through geometric modification rather than material excess, maintaining manufacturing flexibility and avoiding the need for specialized press die designs.
Data Source
Figure 1A~1D
Figure 2A~2D
Figure 3A~3E
AI summary
Provided is a technology capable of suppressing an edge crack occurring due to stretch flange deformation without being constrained by a target pressed component shape. The technology includes two-stage cutting processing of, when it is estimated that there is concern about risk of occurrence of an edge crack due to stretch flange deformation on an edge of a material (1) to be pressed in press forming, performing twice cutting processing on an edge including at least a site where there is concern about risk of occurrence of the edge crack as pre-processing for press forming in which there is concern about risk of occurrence of the edge crack. In the two-stage cutting processing, cutting to form a partial, beam-shaped overhang portion at a position including a site where there is concern about risk of occurrence of the edge crack is performed in the first cutting and the overhang portion is cut in the second cutting.