pECM Workholding With Backside Support for Deflection Control
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Solution Overview
Problem
The force imparted by pulsed electrochemical machining (pECM) causes workpieces to deflect, reducing accuracy and precision, particularly when machining airfoil coversheets clamped at both ends.
Innovation Solution
A pECM system with a backside support configured to stabilize the workpiece span, using mechanisms such as fluid reservoirs, fluid streams, height-adjustable pins, or adhesive-connected pedestals to counteract electrolyte-induced forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pECM is used to machine workpieces, then material removal accuracy is improved, but workpiece deflection increases due to electrolyte-induced forces
Solution Approach 1:
The patent applies counterweight principle by introducing a backside support system that provides opposing force to balance the electrolyte-induced forces during pECM. The support system includes adjustable support elements positioned on the rear side of the workpiece to counteract the deflection forces, thereby maintaining workpiece stability and positioning accuracy during the machining process
2Stability of the object's composition
If clamps are used to hold the workpiece, then workpiece stability is improved, but machining accuracy deteriorates due to deflection from clamping forces
Solution Approach 1:
The patent segments the workholding function into multiple independent components: front clamps for securing the workpiece and backside support elements for counteracting forces. This segmentation allows each component to perform its specific function optimally without interfering with the other, maintaining both stability and machining accuracy
Solution Approach 2:
The backside support system acts as an intermediary element between the workpiece and the machining process. It mediates the forces acting on the workpiece by providing distributed support that counteracts electrolyte-induced deflection, thereby protecting the machining accuracy while maintaining workpiece stability
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 backside support enhances the accuracy and precision of pECM by minimizing workpiece deflection, ensuring precise material removal and formation of complex shapes.
Implementation Method 1
pECM is a non-contact machining process based on the principles of electrolysis. As the tool moves toward a surface of the workpiece to be machined, a pulsed DC current may be applied to the tool and the workpiece. The tool maintains a tiny interelectrode gap (e.g., of less than about 10 microns) from the surface of the workpiece, and the workpiece dissolves anodically about the tool
Data Source
AI summary
A pulsed electrochemical machining (pECM) system includes a pECM tool comprising a tool body defining a tool axis, the tool body comprising one or more electrodes, each of the one or more electrodes comprising an electrically conductive material and defining a working surface at a distal end of the tool axis configured to face a workpiece; an enclosure system configured to hold the workpiece, wherein the enclosure system comprises: a first clamp configured to grip a first end of the workpiece; a second clamp configured to grip a second end of the workpiece; and a backside support configured to support a span of the workpiece between the first end and the second end.