GB969546A - Improvements in or relating to methods and apparatus for removing burrs or the like from workpieces - Google Patents

Abstract

969,546. Deburring by cavitation. ROLLS ROYCE Ltd. Dec. 31, 1962 [Jan. 2, 1962], No. 196/62. Heading B3V. [Also in Division B5] A method of removing burrs or the like from a workpiece comprises immersing the workpiece in a liquid and thereafter creating pressure waves in said liquid in such manner that the liquid adjacent the workpiece oscillates relative thereto, the motion of the liquid relative to the workpiece attaining sufficient speed to produce cavitation in the vicinity of the workpiece. The workpiece 3, e.g. a turbine blade, is secured in a movable support assembly 2 and positioned in a tank 1 of water. A transducer e.g. a magnetostrictive stack 5, is resiliently supported at its mid-point on a bracket 4 such that its lower tip 6 is below the surface of the water and approximately 0.050 above the blade 3. Coils 7, 9 are wound around the lower and upper portions of the stack and are connected to an oscillator 8 and D.C. supply respectively. In operation the coil 9 is energized by the D.C. supply and the oscillator 8 energizes the coil 7 with A.C. at a frequency of 8-16 kc/s. to produce an amplitude of vibration at the tip 6 of 0.003 peakto-peak which produces intense cavitation effects around the blade tip to remove projecting burrs therefrom. During vibration of the tip the support 2 is moved to subject the whole face of the blade to the cavitation effects to effect complete deburring. The transducer may be of the piezo-electric type and the cavitation effect varied by the addition of a wetting agent. The mechanical energy delivered by the transducer may be concentrated by using a " velocity transformer," i.e. an exponentially tapered stud at its tip. The workpiece may be arranged to vibrate in the liquid.