Pulsed DC Current Metal Forming for Complex Parts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The limitations in forming complex metal parts from sheet metal blanks or tubular blanks are due to the metal's formability, often requiring multiple parts to be formed separately and assembled, which increases manufacturing costs and complexity.
Innovation Solution
A method involving the application of pulsed DC current to improve formability, using a forming tool with insulated electrodes to deliver intermittent electrical pulses to the metal blank during the forming process, optionally combined with air flow or cooling to prevent overheating, allowing for increased plastic deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional forming methods are used on sheet metal blanks, then the manufacturing process is simple, but the formability of the metal is limited and complex parts cannot be formed in a single piece
Solution Approach 1:
The patent applies pulsed direct current to the metal blank during forming, changing the electrical and thermal parameters of the metal to improve its formability. The pulsed current modifies the metal's mechanical properties temporarily, allowing greater plastic deformation before returning to its original state, thus enabling complex single-piece forming without excessive process complexity
Solution Approach 2:
The forming process uses periodic pulsed direct current applied to the metal blank. The pulses are applied intermittently during the forming operation, creating periodic changes in the metal's formability that allow progressive deformation beyond conventional limits while maintaining control over the forming process
2Adaptability or versatility
If multiple parts are formed separately and assembled together, then the formability limitations are avoided, but the number of parts increases and manufacturing costs increase
Solution Approach 1:
By changing the electrical and thermal parameters through pulsed direct current application, the metal's formability is enhanced sufficiently to allow entire complex parts to be formed in a single piece, eliminating the need for multiple separate forming operations and subsequent assembly processes, thus improving manufacturing efficiency
Solution Approach 2:
The patent merges multiple forming operations into a single continuous process by applying pulsed current throughout the forming operation, allowing the entire complex part to be formed from one blank in one operation, consolidating what would traditionally require multiple separate forming and assembly steps
3Adaptability or versatility
If pulsed DC current is applied to improve formability, then complex parts can be formed in a single piece, but the blank may overheat leading to grain growth and aging
Solution Approach 1:
The pulsed direct current is applied intermittently rather than continuously, with on/off cycles that allow the metal to cool between pulses. This periodic application delivers the necessary energy to improve formability while preventing excessive heat accumulation that would cause grain growth and aging
Solution Approach 2:
The pulsed current methodology anticipates and prevents overheating by incorporating off-periods in the pulse cycle that allow heat dissipation before excessive temperature buildup occurs. This preliminary anti-action against overheating enables sustained pulsed current application to improve formability without reaching dangerous temperature levels
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 method significantly enhances the formability of metal blanks, enabling the formation of complex parts with increased elongation and reduced grain growth, thereby allowing for the creation of extensively formed parts in a single piece without the need for assembly.
Implementation Method 1
The electrical current is pulsed intermittently from the source of direct current through the portion of the blank in a plurality of pulses having a duration of, for example, between 0.1 and 5 seconds
Implementation Method 2
providing air flow to a portion of the blank during the pulsing step to prevent overheating of the blank which may lead to grain growth and aging
Data Source
AI summary
A method is provided for forming a sheet metal blank or tubular blank in a metal forming tool, such as a sheet metal press or a media forming tool. The sheet metal press has an upper die and a lower die that are moved by a press to form the metal blank. The forming tool has a plurality of electrodes that are connected in an electrical circuit to a source of direct current. The electrodes provide pulses of the electric current to at least a portion of the blank. The method comprises loading the blank into the forming tool and closing the upper die and the lower die. The electrical circuit is completed between multiple electrodes through one or more portions of the blank. Electrical current is pulsed intermittently through the blank in a plurality of pulses.