| 摘要 |
PURPOSE:To maintain always the macromolecule amount of working liquid at a constant level by measuring the coefficient of viscosity of a working liquid and adding a desired macromolecular material thereto in an electric working apparatus using the working liquid. CONSTITUTION:Working liquid is supplied from a working liquid tank 9 through a pump 11, filter 12, adjusting valve 13 and working liquid supplying pipe 5 to a working gap between an electrode 1 and workpiece 2. A working liquid 4 reserved in a working tank 3 is recovered to a working liquid tank 9 through a working recovering pipe 6 by a pump 7. The coefficient of viscosity of this working liquid is measured automatically by a rotation viscosimeter 14 provided in the working liquid tank 9, and when the coefficient of viscosity is lowered below the predetermined lower limit value, marcromolecular material in a storage tank 24 is supplied and added to the working liquid tank 9 to maintain the macromolecular amount therein at a constant level. |
