Experimental study of EDM characteristics using a 5-DOF controllable magnetic levitation actuator

Abstract

The e ciency and accuracy of conventional electrical discharge machining (EDM) is limited by the stability of the voltage between the poles. To improve the e ciency of EDM, this paper proposes a machining method that combines a self-developed 5-degree-of-freedom (5-DOF) controllable magnetic levitation actuator with a conventional EDM machine tool. The stability of the inter-pole voltage is improved by the actuator micro-adjustment the electrodes of the EDM machine tool. Firstly, an EDM control system with local current feedback and decoupling control elements is designed based on the EDM servo drive principle to improve the response speed and positioning accuracy of the actuator. Secondly, the actuator was connected to the spindle of a conventional EDM machine tool, and machining experiments were carried out. The experimental results showed that the EDM machine tool connected to the actuator could control the electrode position more quickly, adjust the discharge state quickly, and increase the number of discharges per unit time. The average machining speed increased from 1.108µm/s to 3.925µm/s, which is 3.54 times faster than conventional EDM. Finally, complex shape machining experiments were carried out and the machining results showed that by adjusting the target value of the radial direction of the actuator, the various trajectories of the electrode could be controlled to depict arbitrary shapes.

Design and Analysis of 5-DOF Compact Electromagnetic Levitation Actuator for Lens Control of Laser Cutting Machine

“…The movable ranges of the rotor in the axial and radial direction are restricted to ±0.3 mm and ±0.5 mm, respectively. Luan [18] and Zhang [19] designed a controllable magnetic levitation actuator for an EDM machine tool to improve the stability of the inter pole voltage, hence the machining speed increases to 3.925 µs. Dongjue He [20,21] designed a novel air core coil type electro-magnetic driving unit to actuate the lens holder, which can achieve a range of ±5 mm with a tracking error of less than 12 µm and a bandwidth of more than 100 Hz in the axial direction.…”