Disk-Shaped Wire Guide for Rotary Wire EDM

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Solution Overview

Problem

Conventional wire guide arrangements in rotary wire EDM processes fail to accurately guide the wire electrode to a rotating workpiece without deflection, leading to contour accuracy issues and potential damage from thermal stress and abrasive grain contact.

Innovation Solution

A disk-shaped wire guide with a thickness less than 1.5 times the wire electrode diameter and a recess in the spark erosion area, allowing for precise guidance and reduced risk of contact with abrasive grains, while maintaining effective flushing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional wire guide arrangement with free span is used in rotary wire EDM, then the wire electrode can reach the workpiece, but the wire electrode is deflected by process forces and hydraulic forces causing contour accuracy issues

Engineering Contradiction:
Improvecontour accuracyVSAvoidwire guidance stability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The wire guide is segmented into multiple support points (first support point, second support point, and third support point) along the wire electrode path. This segmentation provides distributed support to counteract deflection forces while maintaining the necessary wire tension and guidance stability for accurate contour machining.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wire guide acts as an intermediary component between the wire electrode and the workpiece. It provides mechanical support through multiple support points and creates a stable guiding structure that reduces wire deflection caused by process forces and hydraulic forces during rotary wire EDM operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the wire guide is positioned close to the spark gap for direct guidance, then wire deflection is reduced, but the wire guide is exposed to extreme thermal stress and erosion particles causing damage

Engineering Contradiction:
Improvecontour accuracyVSAvoidwire guide durability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

Different sections of the wire guide have different functional qualities. The first support point is positioned close to the spark gap for accurate wire guidance and minimal deflection, while the second and third support points are positioned further away to provide structural support and protect against thermal stress and erosion particle damage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The wire guide function is segmented into multiple support points with different roles. The first support point handles precise positioning near the spark gap, while subsequent support points handle structural support and protection, distributing the thermal and mechanical stresses across multiple locations.

Inventive Principle:
Principle #1Segmentation

3Reliability

If a thick wire guide is used for structural support, then the wire guide is more durable, but it impairs the flushing of the spark gap affecting the erosion process

Engineering Contradiction:
Improvewire guide durabilityVSAvoiderosion process efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The wire guide has varying thickness at different locations. The first support point has sufficient thickness for durability and support, while the second and third support points have reduced thickness to allow dielectric flushing through the wire guide structure, maintaining efficient spark gap cooling and debris removal without compromising overall structural integrity.

Inventive Principle:
Principle #3Local quality

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 enables accurate profiling and sharpening of metal-bonded grinding wheels by minimizing wire deflection and abrasive grain contact, improving contour accuracy and extending the lifespan of the wire guide.

Implementation Method 1

Electroerosive processes are therefore suitable for profiling and sharpening metal-bonded superabrasive grinding wheels, since the binding material is removed selectively.

Methodology Applied
Scientific EffectElectroerosion: Electrical Discharge Machining

Implementation Method 2

The rotation of the workpiece in rotary wire eroding processes (RWEDM, WEDG, WEDD) is very beneficial for the process because the gap flushing is forced by entraining the dielectric; the higher the speed and workpiece diameter, the higher the peripheral speed and thus the flushing effect.

Methodology Applied
Scientific EffectEntrainment: Entrainment

Data Source

PatentEP2732897B1Device for rotational wire electroerosion with pivoting wire guide
Publication Date: 2017.05.03 FRITZ STUDER AG
  • EP2732897B1 patent drawingFigure 1~2b
  • EP2732897B1 patent drawingFigure 3a~3b
  • EP2732897B1 patent drawingFigure 4a~4b

AI summary

The device (20) has main portion that is arranged such that the relative angular position between the wire guide (4) and the workpiece (2) about an pivotal axis (10) parallel to the wire running direction at the operating point (3) is adjustable. A spindle head is provided parallel to the clamped workpiece. A swivel unit is provided for adjusting the relative angular position of the solid state guides. An independent claim is included for disc shaped wire guide for guide of wire electrode.