DESIGN AND TESTING OF LOW DIVERGENCE ELLIPTICAL-JET NOZZLES FOR USE IN CREEP-FEED GRINDING

Abstract

A novel method was developed to design and fabricate nozzles capable of producing low-divergence fluid jets. Nozzle apertures were elliptical, and jets exhibited elliptical cross-sections with divergence varying predictably between 0 and 13°. Nozzle aperture aspect ratios varied from 1.00 to 2.45, area was equivalent to that of a 6mm diameter circle. An elliptical jet was developed with 0.4° and 0.9° divergence in the major and minor axes, respectively. Performance of this elliptical nozzle was compared to that of a circular nozzle via profiled creep-feed grinding trials. Results indicate the circular nozzle performs similarly to the horizontal ellipse; the vertical ellipse frequently caused wheel breakdown. Optimized cutting parameters: wheel speed 23m/s, cut depth 1.78mm, feed rate 200mm/min, jet pressure 3.21MPa or greater. Experiments were performed on a Blohm Planomat 408 CNC grinding machine using CimTech 310 cutting fluid. Nozzle experiments used a Brix concentration of 6.1%, grinding experiments used 3.1%.