AUTOMATIC CONTROL METHOD FOR VIBRATION CUTTING DEVICE

PURPOSE:To enable an eligible control with good accuracy by detecting the mechanical vibration of a tool under vibration cutting as frequency quantity and controlling cutting conditions based on this vibration frequency in a vibration cutting device cutting a tool by its vibration. CONSTITUTION:When a tool holder 3 is fitted into a main shaft 1 and a throttle valve 45 is opened, compressed air is fed into the gap 13 between a tool adaptor 10 and sliding member 11 through an air passage 56 by an air feeding path 43. The main shaft 1 is then rotated and while a normal working is performed by the tool of the adaptor 10, the ball 20, 28 of a torque limit mechanism 18 and thrust limit mechanism 19 are fitted into recessed place 21, 26, the adaptor 10 and a sleeve 8 are rotated together and the adaptor 10 is slightly vibrated in the fore and aft directions. This vibration is increased, reversely transmitted to the adaptor 10 and vibration cutting is executed. Meanwhile, the pressure fluctuation inside and passage 56 is caught as frequency in a pressure sensor 47, compared with a reference frequency and based on this comparison value the number of main shaft rotation and cutting feed amt. are controlled.