Microstructured Bending Die Reduces Springback in Sheet Metal
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Solution Overview
Problem
Metal micro-forming processes face challenges in achieving accurate bending angles due to springback deformation in sheet metal blanks, leading to inconsistencies in finished products that require secondary shaping and processing to meet standards.
Innovation Solution
A bending die with surface microstructures on both the forming surface of the die and the working portion of the punch, featuring intersecting grooves, parallel grooves, and various shapes, reduces friction and stress unevenness during stamping, allowing for complete plastic deformation and minimizing springback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional bending dies with smooth surfaces are used, then the bending process is simple and easy to manufacture, but springback deformation occurs causing inaccurate bending angles
Solution Approach 1:
The patent applies local quality by introducing microstructures (such as micro-grooves, micro-pits, or micro-convexities) only on the contact surfaces of the bending die and punch, while the rest of the die structure remains conventional. This localized modification changes the friction characteristics only where needed - at the contact interface with the workpiece - thereby reducing springback and improving bending angle accuracy without requiring complex changes to the entire die structure.
Solution Approach 2:
The patent employs parameter changes by modifying the surface topology parameters of the bending die and punch through the introduction of microstructures with specific geometries (size, shape, distribution, depth). These parameter changes affect the friction coefficient and stress distribution during bending, leading to reduced springback deformation and improved dimensional accuracy without fundamentally altering the die design concept.
2Manufacturing precision
If microstructures are added to reduce springback, then bending angle accuracy improves, but manufacturing complexity of the die increases
Solution Approach 1:
The patent applies preliminary action by pre-forming microstructures on the bending die and punch surfaces before the actual bending operation. These microstructures are created in advance through surface treatment processes (such as etching, coating, or additive manufacturing), so that during the bending process, the workpiece immediately benefits from the modified surface characteristics that reduce springback, without requiring complex real-time adjustments during manufacturing.
Solution Approach 2:
The patent substitutes traditional mechanical methods of achieving accurate bending (such as multiple passes, complex die geometries, or post-bending adjustment mechanisms) with a surface-level mechanical modification approach. By replacing the need for complex mechanical adjustment systems with microstructured surfaces that inherently control friction and deformation, the manufacturing process is simplified while maintaining high precision.
3Productivity
If conventional smooth surface dies are used, then the die structure is simple, but friction causes stress unevenness and requires secondary processing
Solution Approach 1:
The patent applies local quality by introducing microstructures (such as micro-grooves, micro-pits, or micro-convexities) only on the contact surfaces of the bending die and punch, while the rest of the die structure remains conventional. This localized modification changes the friction characteristics only where needed - at the contact interface with the workpiece - thereby reducing springback and improving bending angle accuracy without requiring complex changes to the entire die structure.
Solution Approach 2:
The patent employs parameter changes by modifying the surface topology parameters of the bending die and punch through the introduction of microstructures with specific geometries (size, shape, distribution, depth). These parameter changes affect the friction coefficient and stress distribution during bending, leading to reduced springback deformation and improved dimensional accuracy without fundamentally altering the die design concept.
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 microstructured bending die effectively reduces springback deformation, ensuring accurate bending angles and reducing the need for secondary processing by minimizing friction and stress inconsistencies in sheet metal blanks.
Implementation Method 1
the plurality of microstructures disposed on a surface of a working portion of a bending punch, and/or on a forming surface of a corresponding die... can reduce the force of friction between a processed blank and a bending die during bending
Implementation Method 2
reduce cases of uneven stress distribution on the sheet metal blank
Data Source
AI summary
Provided are a bending die having surface microstructures and a bending punch thereof applicable to stamping processing to bend a blank to form a shape. The bending die includes a lower die, an upper die, and a workpiece placing piece. The lower die includes a die, and the die includes a forming surface. The upper die includes a bending punch, the bending punch stamps a blank placed on the die in a back and forth stroke, and the bending punch includes a working portion coming into contact with the blank during stamping. The workpiece placing piece is disposed between the upper die and the lower die and used to position or/and press the blank placed on the die. A plurality of microstructures are disposed on the forming surface and/or on the surface of the working portion.