Press Forming Bead Orientation for Curved Panel Wrinkle Prevention
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Solution Overview
Problem
Existing press forming methods for high-strength steel sheets often result in fractures and wrinkles, especially in curved automotive parts, due to limitations in material movement and surface accuracy, and previous technologies have issues with bead deformation and orientation, leading to incomplete prevention of fractures and wrinkles.
Innovation Solution
A press forming method involving a preforming process where convex and concave bead portions are tilted relative to the baseline, followed by a final forming process that causes pseudo shear deformation in the side wall portions, reducing compressive and tensile deformation by aligning bead orthogonal direction with the forming direction, thus preventing fractures and wrinkles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If high-strength steel sheet is used to achieve weight reduction, then weight decreases, but elongation degrades and fractures occur
Solution Approach 1:
The patent applies preliminary action by pre-forming bead portions on the blank material before the main press forming process. These bead portions are strategically positioned and pre-shaped to control material flow during subsequent forming, preventing fractures in high-strength steel sheets by preparing the material structure in advance
Solution Approach 2:
The patent implements local quality by creating bead portions with specific geometric characteristics (convex/concave shapes, predetermined cross-sections) at localized regions of the blank material. These localized structural modifications enable differential material flow control in different regions, allowing the material to accommodate complex forming requirements without fracture
2Ease of manufacture
If conventional press forming is used for curved parts, then forming is simple, but fractures and wrinkles occur
Solution Approach 1:
The patent uses preliminary action by pre-forming bead portions that create controlled material flow patterns during the main forming process. This preliminary structuring of the blank material enables complex curved shapes to be formed without wrinkles or fractures, maintaining surface accuracy while keeping the overall process relatively simple
Solution Approach 2:
The patent applies parameter changes by modifying the geometric parameters of the bead portions (convex/concave configuration, cross-sectional dimensions, spacing, and orientation angles) to control material flow. These parameter variations enable precise control over material distribution, preventing surface defects while forming complex geometries
3Manufacturing precision
If beads are provided to reduce fractures and wrinkles, then surface accuracy improves, but bead deformation and orientation issues occur
Solution Approach 1:
The patent applies asymmetry by configuring bead portions with asymmetric convex and concave shapes rather than symmetric forms. The bead portions have predetermined cross-sections with specific asymmetry that directs material flow in controlled patterns, improving surface accuracy while simplifying the control of bead deformation during forming
Solution Approach 2:
The patent implements local quality by positioning and orienting bead portions with specific geometric properties at different locations on the blank material. Each bead portion is tailored with specific cross-sectional characteristics and orientation angles suited to the local forming requirements, reducing overall system complexity while maintaining high surface accuracy
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively reduces fractures and wrinkles in press-formed products with convex and concave shapes by controlling material movement through pseudo shear deformation, enhancing the surface accuracy and preventing deformation issues in high-strength steel sheets.
Implementation Method 1
squashing the bead portions and extending a surface portion corresponding to the side wall portion in a bead orthogonal direction orthogonal to a long axis of the bead portion so that pseudo shear deformation occurs to the surface portion corresponding to the side wall portion
Data Source
AI summary
A method includes: forming either one or both of convex and concave bead portions at surface portions corresponding to sites of a side wall portion on both sides of a convex curve site and to sites of a side wall portion on both sides of a concave curve site; and squashing the bead portions, wherein the bead portions formed on both sides of the convex curve site are tilted such that an end part of the bead portion positioned on the convex curve site side is farther from a baseline and the other end part is closer to the baseline; and the bead portions formed on both sides of the concave curve site are tilted such that an end part of the bead portion positioned on the concave curve site side is closer to the baseline and the other end part is farther from the baseline.