Wire EDM Auto Feeding with Reversible Airflow Retry

Solution Overview

Problem

The existing wire electrical discharge machines face challenges in auto wire feeding due to wire electrode deflection, which results in prolonged processing times as the motor requires time to transition from starting torque to rated torque during retry processes.

Innovation Solution

Incorporating an airflow generator that generates compressed air in a guide pipe with a passage hole, allowing the air flow direction to switch between forward and reverse directions to gently move the wire electrode, facilitating retry insertion without the need for motor torque transitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the motor is controlled to rewind and feed the wire electrode alternately during retry process, then the wire electrode can be reinserted into the machining hole, but the time required for auto wire feeding becomes long due to motor drive time from starting torque to rated torque

Engineering Contradiction:

Improvewire electrode insertion successVSAvoidauto wire feeding time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the motor-driven mechanical system with a pneumatic system. Compressed air is introduced into the passage hole to directly push the wire electrode tip forward, eliminating the need for motor acceleration from starting torque to rated torque. This substitution of mechanical actuation with pneumatic actuation resolves the time delay issue while maintaining the wire electrode insertion function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces compressed air into the passage hole to propel the wire electrode tip during retry operations. The pneumatic pressure provides immediate force to move the wire electrode without the inertial delays inherent in motor-driven systems. This pneumatic approach directly addresses the time loss problem by providing instantaneous actuation force.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If the wire electrode tip touches the workpiece during insertion, then the wire electrode may be deflected or bent, but the existing retry process requires time-consuming motor torque transitions

Engineering Contradiction:

Improvewire electrode insertion successVSAvoidmachining efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the motor-driven mechanical system with a pneumatic system. Compressed air is introduced into the passage hole to directly push the wire electrode tip forward, eliminating the need for motor acceleration from starting torque to rated torque. This substitution of mechanical actuation with pneumatic actuation resolves the time delay issue while maintaining the wire electrode insertion function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces compressed air into the passage hole to propel the wire electrode tip during retry operations. The pneumatic pressure provides immediate force to move the wire electrode without the inertial delays inherent in motor-driven systems. This pneumatic approach directly addresses the time loss problem by providing instantaneous actuation force.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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 reduces the time required for auto wire feeding by allowing the wire electrode to be reinserted more efficiently, as the compressed air moves the tip in a random manner, compared to traditional motor-controlled rewinding and feeding methods.

Implementation Method 1

an airflow generator configured to generate a flow of compressed air in the passage hole and to switch a flow direction of the compressed air flowing through the passage hole

Methodology Applied

Scientific EffectCompressed air flow: Pressure Gradient

Data Source

PatentUS10974331B2Wire electrical discharge machine and auto wire feeding method of wire electrical discharge machine

Publication Date: 2021.04.13 FANUC LTD

AI summary

A wire electrical discharge machine includes: a guide pipe as a guide member arranged on a path for feeding a wire electrode from a feed roller toward a workpiece and having a passage hole through which the wire electrode is passed; an airflow generator for generating a flow of compressed air in the passage hole and switching a flow direction of compressed air flowing through the passage hole between a forward direction and a reverse direction; a deflection detector for detecting a deflection of the wire electrode; and a control device for controlling the airflow generator so as to generate a flow of compressed air in the forward direction in the passage hole during auto wire feeding and, when the deflection detector detects the deflection, change the flow direction of compressed air to the reverse direction and thereafter switch the flow direction of compressed air to the forward direction.