Creation of U-Shaped and Skewed Holes by Means of Electrical Discharge Machining Using an Improved Electrode Curved Motion Generator

Abstract

This study deals with the development of a new method of machining curved holes for water channels built in molds, holes which cannot be fabricated using current machining methods in practical use. Since holes are generally formed by drilling, water channels are a series of straight holes. This causes obstructions to the smooth flow of the coolant, leading to low efficiency and unstable performance in the cooling of the molds. To solve these problems, the authors have developed new devices that can machine curved holes, thus enhancing the degree of freedom of water channels. An earlier device consisted of simple mechanical parts installed on a die-sinking electrical discharge machine (EDM). It was able to fabricate an L-shaped curved hole. However, the controllability of the shape of the curved holes it produced was unfortunately low. To overcome this weakness, the device has been improved and now it can machine curved holes of a variety of shapes. Through application experiments, it has been found that U-shaped and skewed holes, holes which cannot be produced using conventional machining methods, can also be created employing the improved device.