| 摘要 |
PURPOSE:To reduce variations of tension in a wire electrode and to simplify an actuating mechanism for the wire electrode by rotating a wire electrode feed roller and a wire electrode takeup roller at a same speed from a same driving source while maintaining constant the elongation of the wire electrode arising from the difference between diameters of both rollers. CONSTITUTION:Discharge energy is applied to a workpiece 1 through energizing terminals 3, 3' to produce pulse discharging to effect electrospark machining of the workpiece 1. A wire electrode feed roller 12' and a wire electrode takeup roller 13' are secured to a single driving shaft 20 so that they can be rotated at a same speed from a common driving source of a wire electrode driving motor 22. The diameter D1 of the roller 12' and the diameter D2 of the roller 13' are selected to be in a relationship D1<D2 so that the difference between both diameters may provide a required tension to the wire electrode 2 which passes an electrospark machining station. Even if the electrode 2 is locally overheated by concentrated discharging or the like to thereby produce an extraordinary elongation of the electrode 2, the tension is instantaneously reduced at the same time with the production of such an extraordinarly elongation and will present no more increase thereof due to the fact that the difference between feeding amounts of both rollers 12', 13' is constant. |
