Basic Study Of Stranded-Wire Electrical Discharge Machining

Cooling liquid is one of the most important factors that affect the WEDM normal discharge, it goes into the discharging gap by adhering to the moving electrode wire. At present, in the large energy cutting(average cutting current is 7A or higher) using compound cooling liquid, the cooling liquid in the discharging gap vapors seriously due to processing power is too large, the normal discharge condition can't be maintained because of insufficient cooling liquid so that the cutting efficiency drops, and after the burn marks come out on the cutting surface. Therefore, to make the wire electrode bring more cooling liquid into the the discharging gap and more corrosion product out, this paper proposes a new type of WEDM processing electrode with the idea of the stranded-wire electrode.This paper contains some work about the stranded-wire electrode applied research in the high efficiency WEDM, the design and manufacture of the double stranded-wire electrode production equipment, the simulation calculation of the flow field of stranded-wire electrode and cylindrical wire electrode in WEDM using fluid mechanics calculation software “Fluent”, the experiment to verify the simulation results, the study of the specific processing property of stranded-wire electrode in WEDM with different discharge energy and wire walking speed, as well as the influence of the pitch on the cutting performance.The main research content is as follows:(1) Put forward the scheme of the double stranded-wire electrode production device in back-twist, twisting, tension control, wire collecting and winding pitch control, and according to the scheme, the design and manufacture of specific parts was carried on.(2) Simulated the flow field of stranded-wire electrode and cylindrical wire electrode in WEDM using “Fluent”, found that the volume flow rate of the flow field with stranded-wire electrode is higher than that of cylindrical wire electrode, the cooling liquid in the flow field with stranded-wire electrode has the circumferential velocity component, in favor of speeding up the recovery of insulating state between the electrodes. Designed the fluid experiment with stranded-wire electrode and cylindrical wire electrode, the experimental results verify the simulation results.(3)Studied the specific processing property of stranded-wire electrode in WEDM with different discharge energy and wire walking speed, compared with cylindrical wire electrode, because the volume flow rate of stranded-wire electrode is bigger, making the cooling, deionization and cleaning in the processing area more sufficiently so that the processing condition is better, as a result, the stranded-wire electrode gets higher cutting speed and better surface when the cutting energy is large or the wire speed is slow.(4) The influence of the winding pitch on the stranded-wire electrode in WEDM was studied, when the winding pitch increases, the cutting speed increases and the surface quality improves, through the analysis, found that the volume of stranded-wire spiral groove is proportional to the winding pitch, thinking that the increasing of the spiral groove size of the stranded wire electrode can promote the cooling, deionization, cleaning, and improve the processing performance.