Fundamental Study on Jetting Nozzle Diameter for Smooth Debris Exclusion in Wire EDM

Abstract

This paper fundamentally investigated the influence of nozzle inner diameter on flow field in the kerf, debris exclusion and wire deflection in wire EDM, by using CFD analysis and structural analysis. It was found that in the case of constant flow velocity from the nozzle, the stagnation region of working fluid in machined kerf becomes smaller and debris exclusion becomes better with the increase in nozzle inner diameter. In addition, since the wire deflection changes very little with nozzle diameter, it can be considered that the increase in nozzle inner diameter has little influence on shape accuracy. Furthermore, in order to verify the analysis results, the wire EDM characteristics with different nozzle inner diameters were experimentally investigated. The results showed that the removal rate increases and the machined surface roughness changes very little with the increase of nozzle diameter, which agree well with the simulation results.