3D Draft Angle Sculpting for Mold-Removable CAD Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CAD systems struggle to automatically generate 3D models that satisfy overhang and draft requirements for casting and molding processes, leading to mold interference and increased manufacturing complexity and costs.
Innovation Solution
A draft angle sculpting process is implemented in CAD software to automatically remove overhangs and undercuts, ensuring the mold can be removed without interference, by applying a mold removability filter during shape synthesis, which can be integrated into generative design and topology optimization algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If automatic 3D geometry generation is performed using topology optimization or generative design, then design efficiency and optimization objectives are improved, but the generated geometry often fails to satisfy overhang and draft requirements for casting and molding processes
Solution Approach 1:
The patent applies draft angle sculpting and overhang removal as preprocessing steps during the generative design process. The system proactively modifies the generated geometry to include draft angles and remove overhangs before the geometry is finalized, ensuring manufacturability is built into the design rather than added as a post-processing correction.
Solution Approach 2:
The patent applies draft angles and overhang removal selectively to specific regions of the geometry based on local requirements. The draft angle sculpting process identifies regions that need draft angles for mold removal, and the overhang removal process targets specific overhanging regions, applying modifications only where necessary rather than uniformly across the entire part.
2Ease of manufacture
If draft angles are added to vertical surfaces to enable mold removal, then mold removability is improved, but the geometric complexity of the part increases
Solution Approach 1:
The patent applies draft angles selectively only to vertical surfaces that require mold removal, rather than applying draft angles uniformly to all surfaces. The system identifies specific regions where draft angles are necessary for mold removability and applies modifications only to those localized areas, minimizing the overall increase in geometric complexity.
Solution Approach 2:
The patent applies draft angles with a magnitude that is sufficient to enable mold removal but not excessive. The system calculates and applies the minimum necessary draft angle to achieve mold removability, avoiding unnecessary geometric complexity while ensuring the mold can be successfully removed from the part.
3Ease of manufacture
If overhangs are removed to prevent mold interference, then mold removal is facilitated, but material is added to the part geometry
Solution Approach 1:
The patent identifies and removes overhanging regions from the geometry that would cause mold interference. The overhang removal process extracts problematic geometric features that prevent mold removal, converting the design to ensure the mold can be successfully extracted from the part after casting or molding.
Solution Approach 2:
The patent modifies geometric parameters of the part, specifically adjusting the draft angles and removing overhanging features. By changing these geometric parameters, the system ensures that the mold can be removed without interference while accepting the necessary material additions to achieve the required geometric modifications.
4Loss of time
If CAD systems perform automatic generation of 3D geometry, then design time is reduced, but the generated designs require manual intervention to satisfy manufacturing constraints
Solution Approach 1:
The patent implements automated draft angle sculpting and overhang removal functionality within the CAD system itself. The system performs these manufacturing constraint satisfaction operations automatically during the design process, eliminating the need for manual intervention. The CAD system serves itself by integrating generative design with manufacturing constraint enforcement, fully automating the process from geometry generation to manufacturability verification.
Data Source
AI summary
Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design of physical structures using three-dimensional model synthesis processes. A method includes: obtaining a draft angle, an ejection direction, and a 3D shape for a casting or molding process; modifying data values in discrete elements (from which the 3D shape is determinable) to add material to the modelled object, including, for each of the discrete elements, changing a current value of the discrete element based on a comparison of the current value with an other value and a constant value, the other value being determined from one or more values found in one or more other discrete elements in the data structure located away from the discrete element along the ejection direction, and the constant value being determined for the draft angle; and providing the data structure with the modified data values for further processing.