ANALYSIS AND OPTIMIZATION OF PARAMETER AFFECTING BORE DEVIATION IN BORING PROCESS

This investigation applies a full factorial orthogonal table, integrating response surface methodology (RSM) to optimize parameters of a finish boring process using a computer numerical control (CNC) machine VA-50 for the finishing operation of engine crank case tappet bore. The main scope of this research work is to study the effects of various operational parameters like cutting speed, feed rate and cutting allowance on bore diameter of engine crankcase tappet bore. It is found that with the increases of cutting speed and feed the bore deviation (BD) decreases. The result of the experiment then was analyzed using DESIGN EXPERT (DOE) 9.0 software. This was done by using the FULL FACTORIAL technique with optimal (custom) design and ANOVA analysis. In this study, randomization of the run order to be carried out and analysis sequences were carried out according to the run order by Design Expert software. Full factorial with optimal design of three factors with two factor have three levels and one factor has two level was conducted which consist of 18 runs. The machining responses that were analyzed is Bore deviation (BD).All data obtained were then used as input to the Design Expert software for further analysis, according to steps outline for full factorial design. As speed and feed increased a decrement of Bore deviation approximately 40 % was observed. By applying RSM analysis, the predictive mathematical model of the bore deviation average was developed in terms of the cutting speed, feed rate, and cutting allowance. The error analysis and experimental results indicate that the proposed predictive mathematical models could adequately describe the performance indicators within the limits of the factors that are being investigated. In addition, the analysis of variance (ANOVA) was implemented to identify the significant factors and the response surface contours were constructed for determining the optimum conditions of finish boring processes using CNC machine operations.