| 摘要 |
PURPOSE:To prevent machining fluid from its blackening due to a progress of electric discharge machining, by using the machining fluid in which oil of high viscosity is added to mineral oil or synthetic oil of low viscosity. CONSTITUTION:Mineral oil or synthetic oil of low viscosity with its 50% distilled temperature at 200 deg.C or less is used for the base oil as machining fluid of electric discharge machining, while the machining fluid, in which 1-30% by volume of oil of high viscosity with its dry point at 300 deg.C or more is added to said base oil, is used. A flash point of 70 deg.C or more is preferable for the base oil. A surface active agent, being not contained, can prevent a phenomenon, in which the machining fluid is blackened by dispersing a tar ingredient in the machining fluid, while improve a machining characteristic. |
