Abstract
In wire electrical discharge machining, debris tends to stagnate around the wire electrode, since the machined kerf is narrow, secondary discharges often occur, and discharges easily concentrate on the same location, which leads to unstable machining performance, such as wire breakage, low machining rate and low shape accuracy. Thus, better exclusion of debris and bubbles from the machined kerf is very important to obtain stable electrical discharges and high machining accuracy. Conventionally, the debris exclusion from the gap has been carried out by jet flushing of working fluid from upper and lower nozzles. This study aims to propose new jet flushing methods for high-performance wire EDM characteristics by using computational fluid dynamics (CFD) analysis. In this paper, a nozzle jet flushing method with a fine insert following behind the wire electrode, is newly proposed. As results, it is found that debris exclusion can be improved by the insert nozzle flushing method, because of its straightening effect of working fluid flow around the wire electrode. It is also confirmed that the wire EDM characteristics can be improved practically by using the insert nozzle flushing method.
