Wire EDM Power Feed Contact Offset for Cut Surface Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wire electric discharge machining apparatuses face issues with machining accuracy due to surface cracks and debris generation on the wire electrode, leading to uneven cut surfaces and reduced machining speed, as a result of friction between the wire electrode and power feed contacts.
Innovation Solution
The apparatus includes a power feed contact movement device that adjusts the offset distance of the upper and lower power feed contacts based on machining conditions such as wire electrode material, diameter, and required surface roughness to minimize contact pressure and prevent surface damage, allowing for precise control of power supply to the wire electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the contact pressure between the wire electrode and the upper power feed contact is increased to maintain adequate power supply, then the power supplied to the wire electrode is sufficient, but cracks and debris are generated on the surface of the wire electrode due to friction, reducing machining accuracy
Solution Approach 1:
The patent applies dynamics by making the contact pressure between the power feed contact and wire electrode variable rather than constant. The control device adjusts the contact pressure according to machining conditions (such as wire material, diameter, and required surface roughness), allowing the system to optimize between power supply adequacy and surface damage prevention dynamically during the machining process
Solution Approach 2:
The patent implements parameter changes by modifying the contact pressure parameter based on different machining conditions. The control device changes the contact pressure parameter according to wire electrode material, diameter, and required surface roughness, enabling the system to adapt power transmission while minimizing friction-induced surface damage
2Manufacturing precision
If the contact pressure between the wire electrode and the upper power feed contact is reduced to suppress friction, then cracks and debris generation is minimized, but the power supplied to the wire electrode is reduced, lowering machining speed
Solution Approach 1:
The system dynamically adjusts contact pressure based on real-time machining conditions. For finishing operations requiring high surface quality, the contact pressure is reduced to minimize friction. For roughing operations where speed is prioritized, the contact pressure is increased to ensure adequate power supply, thus dynamically optimizing both surface quality and machining speed
Solution Approach 2:
The control device changes the contact pressure parameter according to the specific machining stage and requirements. By adjusting this parameter, the system can prioritize surface quality when needed while maintaining adequate power supply for productivity when surface quality requirements are less stringent
3Stability of the object's composition
If a fixed contact pressure is applied between the power feed contact and wire electrode, then the power supply is stable, but the system cannot adapt to different machining conditions such as wire material, diameter, or required surface roughness
Solution Approach 1:
The patent transforms the static contact pressure system into a dynamic one controlled by a control device. The control device receives information about machining conditions (wire material, diameter, required surface roughness) and adjusts the contact pressure accordingly, providing both stability through controlled power supply and adaptability to varying machining requirements
Solution Approach 2:
The system implements feedback control where the control device monitors machining conditions and adjusts the contact pressure based on this information. This feedback mechanism enables the system to maintain stable power supply while adapting to different wire materials, diameters, and surface roughness requirements by continuously optimizing the contact pressure parameter
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 solution enhances machining accuracy while maintaining machining speed by reducing surface cracks and debris on the wire electrode, resulting in smoother cut surfaces and improved processing efficiency.
Implementation Method 1
generates a discharge in a work gap formed between a moving wire electrode and a workpiece to machine the workpiece
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An upper guide assembly (41a) includes an upper wire guide (43a), an upper power feed contact (44a), and a power feed contact movement device (45), and a lower guide assembly (41b) includes a lower power feed contact (44b). The upper power feed contact and the lower power feed contact contact the wire electrode (2) to supply power by moving in a horizontal direction from initial positions (Al, A2) not contacting the wire electrode. The power feed contact movement device moves the upper power feed contact in the horizontal direction from the initial position by a predetermined offset amount (dl). The offset amount is set based on a machining condition including at least one of a condition of the wire electrode, a condition of a workpiece (W), and a surface roughness required for a cut surface of the workpiece.