Segmented Hot Forming Tool With Thermal Expansion Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hot forming tools with segmented designs face challenges in maintaining adequate abutting contact between mold surfaces and sheet metal blanks due to differential thermal expansion, leading to an unclear transition zone between hardened and unhardened regions in press-hardened components.
Innovation Solution
A hot forming tool with a top and bottom tool, where at least one segment is designed as a heating segment equipped with a compensating element to manage thermal expansion, ensuring consistent mold surface contact and defining a sharply transition region between microstructural states of varying hardness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the press forming tool is segmented to suppress thermal conduction and enable partial hardening, then manufacturing precision of transition regions is improved, but differential thermal expansion between segments causes loss of abutting contact between mold surfaces and blank
Solution Approach 1:
The patent applies parameter changes by modifying the physical state of the compensating element (spring) to accommodate thermal expansion. The spring is pre-compressed to store elastic energy that compensates for the thermal expansion of heated segments, maintaining constant contact pressure between mold surfaces and the blank throughout the heating process
Solution Approach 2:
The patent implements beforehand cushioning by pre-compressing the spring compensating element before thermal expansion occurs. This pre-compression creates a cushioning force that actively counteracts the upcoming thermal expansion, ensuring continuous abutting contact is maintained from the start of heating through the expansion process
2Manufacturing precision
If thermal conduction in the blank is reduced to sharpen the transition zone, then manufacturing precision is improved, but heat distribution uniformity deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the press forming tool into multiple independently temperature-controlled segments. This allows different regions of the blank to experience different thermal conditions simultaneously, creating sharply defined transition zones while maintaining overall temperature distribution control through independent segment management
Solution Approach 2:
The patent implements local quality by enabling each tool segment to have independent temperature control characteristics. This allows specific local regions to be heated or cooled at different rates and to different temperatures, creating the desired sharp transition zones in specific areas while maintaining uniform temperature distribution in other regions
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 solution effectively compensates for thermal expansion, achieving a sharply defined transition region between hardened and unhardened areas, ensuring precise microstructural states and improved forming accuracy in hot formed and press-hardened components.
Implementation Method 1
the expansion owing to the different temperatures generated in the segments of the top tool and/or the bottom tool can be compensated for
Implementation Method 2
the thermal conduction inside the blank and also the thermal conduction inside the press-forming tool
Implementation Method 3
the sheet metal component that is produced is cooled so rapidly that the austenitic microstructure is transformed into a substantially martensitic microstructure or into a mixed microstructure
Data Source
AI summary
A hot forming tool includes a top tool and a bottom tool, both of which can be moved towards each other. When the hot forming tool is closed, a mold cavity is formed between the top tool and the bottom tool, with the top tool and/or the bottom tool being divided into at least two segments. The hot forming tool has one segment designed as a heating segment. The heating segment includes a compensating element on a side thereof opposite the mold cavity, to compensate for a thermal expansion of the heating segment in the press stroke direction.