An Investigation Into the Influence of Ultrasonic Servo Feed Drive Technology in Electro Discharge Machining Industrial Applications

Abstract

This paper demonstrates the investigation carried out into the influence of ultrasonic servo feed drive technology, in electro discharge processing systems, industrial applications. The drive was mainly designed to replace the existing servo control drive using electromagnetic servo technology. This was aimed to improve the electro discharge servo control system stability, quality of the machined products surface profiles, and system dynamic time response. Evaluation has been undertaken to examine the developed servo control feed drive, in two industrial applications, electro discharge machining and electro discharge texturing. Two arrangements were used, in this investigation. The existing servo control feed drive system, which uses electromagnetic servo drive, and the developed system, which uses piezoelectric ultrasonic feed drive. The electro discharge processing parameters, including current level, the on-off time and the duty cycle of the machining pulse were the main processing parameters of this investigation. The electron microscopic micro examination into the machined and textured samples showed that: piezoelectric ultrasonic feed drive showed a clear improvement in the quality of surface finish of the machined samples, due to the fast dynamic time response of the developed drive. This was accompanied with a notable reduction in the arcing and short-circuiting teething phenomena. This was verified by assessing the electrode movements, the variations in the inter electrode gap voltage, current and feedback control signals.