Curved ISF Tool Paths for Better Surface Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Incremental sheet forming (ISF) techniques face issues with surface quality due to traditional tool path algorithms that intersect designs with parallel horizontal planes, leading to undesirable surface quality, especially in concave or convex workpieces, and limited bi-directional toolpath capability, resulting in material thinning and formability limitations.

Innovation Solution

A tool path algorithm that generates continuous alternating curved transitions with bi-directional tool paths, allowing the forming tool to move smoothly between planar parallel alternating paths connected by curved transitions, improving surface quality and reducing distortion by adapting to complex geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional tool path algorithms use parallel horizontal planes perpendicular to the tool axis, then the tool path is simple to generate, but undesirable surface quality results in transition areas especially for concave or convex workpieces

Engineering Contradiction:
Improvesurface qualityVSAvoidtool path complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies curvature by replacing traditional linear transition segments with curved transition segments that follow the contour of the workpiece. The curved transitions are generated by intersecting the design surface with a series of parallel planes and connecting the intersection points with curves that adapt to the local geometry, thereby eliminating surface defects in transition areas while maintaining a systematic tool path structure

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The tool path is segmented into multiple types of segments: horizontal segments for planar regions, vertical segments for depth transitions, and curved segments for contour transitions. This segmentation allows each segment type to be optimized independently for its specific function, improving overall surface quality while keeping the generation process structured and manageable

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If traditional machining tool paths are used for incremental sheet forming, then the tool path generation is straightforward, but material thinning occurs and formability is limited

Engineering Contradiction:
ImproveformabilityVSAvoidmaterial thickness uniformity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The tool path generation dynamically adapts to the workpiece geometry by calculating curved transitions that follow the actual contour. The tool moves along paths that are continuously adjusted based on the intersection of parallel planes with the design surface, allowing the process to accommodate complex geometries and varying material flow requirements, thereby improving formability and reducing material thinning

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the tool path parameters from fixed linear transitions to variable curved transitions. By modifying the transition segment geometry to follow the workpiece contour, the material flow during forming is optimized, preventing excessive thinning in critical areas and expanding the range of formable geometries

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3557347B1Generating a plurality of curved transitions connecting planar parallel alternating paths for forming a workpiece
Publication Date: 2021.05.12 THE BOEING CO
  • EP3557347B1 patent drawingFigure 1
  • EP3557347B1 patent drawingFigure 2
  • EP3557347B1 patent drawingFigure 3

AI summary

A method is presented. A tool path having planar parallel alternating paths connected by a plurality of curved transitions is generated. A forming tool is driven along the planar parallel alternating paths and the plurality of curved transitions to shape a material into a workpiece.