Sheet Metal Blank Destacker Using Electromagnetic Pulse Separation
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Solution Overview
Problem
Existing methods for separating sheet metal blanks, particularly aluminum or non-magnetic blanks, are inefficient due to the vacuum effect and oil film adhesion, leading to surface imperfections during forming operations.
Innovation Solution
An apparatus using an electromagnetic pulse generated by a multi-turn coil and insulated metal screen to separate the top blank from a stack, combined with suction cups to lift and transfer the blank, effectively overcoming the vacuum and adhesion issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fanner magnets are used to separate steel blanks, then the vacuum effect is eliminated, but the method is ineffective for aluminum or non-magnetic blanks
Solution Approach 1:
The patent replaces the magnetic field-based fanner magnet system with an electromagnetic pulse system that uses rapidly changing magnetic fields to induce eddy currents in non-magnetic conductive materials like aluminum. This substitution allows the same separation mechanism to work effectively with both magnetic and non-magnetic materials by utilizing different physical responses (magnetic attraction versus electromagnetic induction).
Solution Approach 2:
The patent changes the operational parameters of the magnetic field from static or slowly varying (as in fanner magnets) to rapidly pulsing electromagnetic fields. This parameter change enables the system to interact with non-magnetic conductive materials through eddy current induction, thereby expanding material compatibility while maintaining reliable separation.
2Productivity
If air knife is used to separate aluminum blanks, then separation is achieved, but dust particles and slivers are blown onto blank surfaces
Solution Approach 1:
The patent replaces the mechanical air knife system with an electromagnetic pulse system. Instead of using high-velocity air streams that physically contact and contaminate blank surfaces, the electromagnetic system uses field-based forces to induce eddy currents and create repulsive forces for separation. This substitution eliminates surface contamination while maintaining effective separation of non-magnetic aluminum blanks.
3Strength
If suction cups are pressed against blanks to lift them, then the top blank is secured, but the vacuum effect causes adhesion to the stack
Solution Approach 1:
The patent applies electromagnetic pulses to the stack of blanks before the suction cups make contact or while they are just engaging. This preliminary electromagnetic action creates repulsive forces between adjacent blanks, pre-separating them and reducing the adhesion force that the suction cups would otherwise encounter. This timing sequence allows the suction cups to grip the top blank more easily without being hindered by strong vacuum adhesion to the stack.
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 electromagnetic pulse generates a force stronger than the inter-blank vacuum and oil film adhesion, allowing for clean separation of sheet metal blanks without surface imperfections, improving the efficiency of sheet metal stamping processes.
Implementation Method 1
an electromagnetic pulse is generated by discharging the source of stored charge to separate the top blank from the stack. Electric current runs through the multi-turn coil creating an electro-magnetic field that induces electrical currents in both the screen and the upper layer of blanks
Implementation Method 2
suction cups perform the primary lifting function and are connected to a vacuum source. The suction cups are pressed against the non-magnetic sheet metal blank, e.g. an aluminum alloy blank, and vacuum is provided to secure the suction cups to the top blank
Data Source
AI summary
An apparatus for de-stacking sheet metal blanks uses electro-magnetic pulses to separate sheet metal blanks from a stack of blanks. A fixture supports an electromagnetic attraction device that includes one or more multi-turn electrical coils and one or more insulated metal screens. The coil is electrically connected to a bank of capacitors. The metal screen is disposed in an electrical insulation material and is retained by the fixture between the coil and the top blank of the stack of blanks. Suction cups perform the primary lifting function and are connected to a vacuum source. The suction cups may be supported by the same fixture or another associated fixture that cooperates with the coil and insulated screen.