No abstract

Purpose This paper aims to determine the rational operating regime of a rotary percussive drilling machine under optimal conditions. Design/methodology/approach An orthogonal array of Taguchi, signal-to-noise (S/N) ratio, ANOVA Pareto analysis and regression analysis are used to investigate the effect of drilling operational factors on the penetration rate. A series of experiments based on orthogonal arrays L27 was carried out, and the results were collected and analyzed using the statistical software Minitab. Findings The statistical analysis (ANOVA Pareto) of the results showed that among all setting parameters, air pressure is the most essential element that affects the penetration rate. The rational operating regime of the rotary percussive drilling machine was determined with optimum air pressure values of 17 bar (Level 3), rotation speed of 60 rpm (Level 3) and a thrust of 825 kgf (Level 2), which maximize the penetration rate. A quadratic regression model was developed for the penetration rate. The predicted values are compared with the experimental data and are considered to be in good agreement. Originality/value The study uses the orthogonal array of Taguchi, S/N ratio, ANOVA Pareto analysis and regression analysis to investigate the effect of drilling operational factors on the penetration rate.