Deep-Drawn Half-Shells with Compressed Cross-Sections
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Solution Overview
Problem
Existing methods for producing closed hollow profiles, such as those used in motor vehicles, face issues like material expansion leading to cracks, uncontrollable wrinkling, and high complexity and cost due to springback in deep-drawn half-shells, making precise positioning and welding challenging, especially when trying to form flangeless profiles.
Innovation Solution
A method where the entire cross-section of a preformed half-shell is compressed during forming to distribute excess material evenly, increasing wall thickness and aligning stresses for reduced resilience, allowing for precise welding in I-joints without protruding weld seams and minimizing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If deep-drawing is used to produce half-shells, then the half-shells can be formed from a blank, but stresses are introduced that cause springback making precise positioning and welding difficult
Solution Approach 1:
The patent applies preliminary action by performing an intermediate forming step (pre-forming) before the final deep-drawing operation. The blank is first pre-formed into a pre-formed half-shell with a predetermined shape, then this pre-formed shell is used as a blank for the final deep-drawing. This preliminary shaping action reduces the springback effect in the final product, enabling precise positioning and welding without requiring complex compensation measures.
2Shape
If hydroforming is used to produce closed hollow profiles, then the profiles can be formed to final shape, but local expansion exceeds material limits causing cracks and uncontrollable wrinkling
Solution Approach 1:
The patent segments the forming process into distinct stages: first forming individual half-shells through deep-drawing, then welding them together to form the complete closed hollow profile. This segmentation avoids the problematic single-step hydroforming process that causes local expansion beyond material limits. By dividing the operation into manageable stages with controlled material flow, the method eliminates cracks and wrinkling while achieving the desired final shape.
Solution Approach 2:
Instead of forming the complete closed profile directly through hydroforming (the conventional approach), the patent inverts the sequence by first forming open half-shells and then joining them. This reversal of the forming sequence allows better control over material deformation, preventing the local expansion issues that occur when attempting to form the entire profile in one operation.
3Ease of manufacture
If flange areas are used for welding half-shells, then welding is possible, but the protruding weld seam increases overall weight and limits application
Solution Approach 1:
The patent applies local quality by creating localized thickening of the half-shell walls at the welding regions through the deep-drawing process. This localized material accumulation provides sufficient material for welding without requiring protruding flanges. The welding area has enhanced thickness and material availability, while the rest of the structure maintains optimal weight, thus eliminating the need for heavy flange extensions.
4Strength
If conventional deep-drawing is used to produce half-shells with thickened edge areas, then excess material is pressed into edge areas, but the process is complex and the half-shells still have springback forces
Solution Approach 1:
The patent merges the pre-forming operation with the final deep-drawing operation into a single integrated process. The pre-formed half-shell is used directly as the blank for deep-drawing, combining what were previously separate operations. This integration simplifies the overall process and equipment requirements while maintaining the beneficial effects of pre-forming, including reduced springback and adequate material availability for welding.
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
This approach results in highly dimensionally stable, cost-effective half-shells that can be easily welded together, reducing tolerances and production costs by eliminating springback and enabling efficient use in motor vehicle construction with improved material distribution and reduced complexity.
Implementation Method 1
the entire cross section is compressed to form the finished half-shell
Implementation Method 2
excess material that is pressed from the base area into the edge areas between the frame and base area
Implementation Method 3
the stresses introduced into the preformed half-shell during pressing are aligned in vertical directions in the area of the frame and in horizontal directions in the area of the base
Data Source
Figure 1
Figure 2a~2b
Figure 3
AI summary
The invention relates to a method for producing highly dimensionally accurate, deep-drawn half shells having a floor area (3) and a notch (2), wherein a preformed half shell (1) is first formed from a circuit board. The task of providing a method for producing highly dimensionally accurate half shells, with which highly dimensionally accurate half shells which can be easily welded to one another can be manufactured cost-effectively with minimal machined-based complexity, is achieved according to the invention in that due to the geometric shape the entire cross-section of the preformed half shell (1) has excess circuit board material, the entire cross-section is compressed by the excess material in the final shape thereof during reshaping of the preformed half shell (1) by way of at least one more pressing procedure into the finished half shell, and the finished half shell has an enlarged wall thickness substantially over the entire cross-section.