Overlapping ECM Electrodes for Uniform Blade Surface Machining

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Solution Overview

Problem

Existing electrochemical machining (ECM) devices for metal workpieces, particularly turbomachine blade components, face issues with inhomogeneous surface treatment due to gaps between electrodes, leading to incomplete processing and surface inhomogeneities, especially at edge areas with acute angles.

Innovation Solution

The electrodes are designed to touch and overlap during the adjustment movement, maintaining a permanent closed fluid channel, ensuring all workpiece areas are uniformly processed by maintaining contact and sealing the fluid channel with sliding surfaces, allowing for homogeneous machining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If electrodes are spaced apart during adjustment movement to allow movement under undercuts, then ease of operation is improved, but manufacturing precision deteriorates due to inhomogeneous surface treatment

Engineering Contradiction:
Improveelectrode movement capabilityVSAvoidsurface treatment homogeneity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The electrodes are pre-positioned in an overlapping arrangement at their edges before the adjustment movement begins. This preliminary overlapping ensures that the fluid channel is already sealed and all workpiece areas are covered by imaging surfaces from the start of the movement, preventing the formation of inhomogeneous zones that would occur if electrodes were spaced apart.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If electrodes are spaced apart to enable linear movement, then device flexibility is improved, but manufacturing precision deteriorates due to unmachined areas between electrodes

Engineering Contradiction:
Improveelectrode positioning flexibilityVSAvoidcomplete coverage of workpiece areas
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The imaging surfaces of adjacent electrodes are designed to overlap, merging their functional coverage areas. This merging ensures that the entire workpiece surface is continuously covered by at least one imaging surface throughout the adjustment movement, eliminating unmachined zones and ensuring homogeneous material removal across all areas including edges and corners.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If electrodes touch and overlap throughout adjustment movement, then manufacturing precision is improved through homogeneous processing, but device complexity increases due to sealing requirements

Engineering Contradiction:
Improvesurface treatment homogeneityVSAvoidfluid channel sealing structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The electrodes themselves perform the sealing function through their overlapping arrangement and the resulting contact between their imaging surfaces. The fluid channel is sealed automatically by the geometric overlap of electrodes, eliminating the need for separate sealing elements or complex sealing mechanisms. The electrodes self-generate the seal through their positioning and contact.

Inventive Principle:
Principle #25Self-service

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 a homogeneous processing pattern and significantly improved workpiece quality by ensuring all areas are machined uniformly, eliminating edge effects and inhomogeneities, and allowing for flexible electrode arrangement and precise positioning.

Implementation Method 1

For machining metal workpieces made of electrically conductive material, an electrochemical machining (ECM) process is used

Methodology Applied
Scientific EffectElectrochemical machining (ECM): Electrolysis

Implementation Method 2

This channel encircles the workpiece, allowing an electrolyte to circulate within it, absorbing and removing the dissolved material

Methodology Applied
Scientific EffectElectrolyte circulation and material dissolution: Electrolysis

Data Source

PatentEP3403754B1Device and method for electro-chemical processing of one metallic workpiece
Publication Date: 2023.05.24 LEISTRITZ TURBINENTECHN NURNBERG GMBH
  • EP3403754B1 patent drawingFigure 1~4
  • EP3403754B1 patent drawingFigure 5
  • EP3403754B1 patent drawingFigure 6

AI summary

Device for the electrochemical machining of a metal workpiece, comprising a plurality of electrodes which can be moved linearly from an initial position to an end position relative to the workpiece via respective linear drive units and have an imaging surface directed towards the workpiece, with at least three electrodes (4, 5, 6, 7) being provided, which are are arranged offset around the circumference of the workpiece (2) and touch one another in sections with their imaging surfaces (13, 14, 15, 16) during the entire adjustment movement from the starting position to the end position and with their imaging surfaces (13, 14, 15, 16) delimit a fluid channel (12) which is closed around the circumference of the workpiece (2).