A smart stamping tool for punching and broaching combination

The crescent search for production time reduction is a factor that stimulates the improvement of the existent manufacturing techniques. In this work, a combined process using tools that perform punching followed by broaching in only one operation is studied in order to obtain holes with improved precision and surface finish. This researched combo process should make possible the manufacturing of pieces in less time with better use of material and equipment. This allows the use of only one process for heavy-duty jobs on thick sheet metal. In order to study this process, eighteen tools with three types of geometry with parallel and nonparallel cutting angle were made. Tool lubrication/cooling conditions were also analyzed using cutting fluids with concentrations of 100, 75 and 50% Hislip with respective 0, 25 and 50% of water. The hole final surface roughness, diameter and conical form, cutting tool angles, tool temperatures and cutting tool degradation were analyzed. The data obtained through the analysis of the variance (ANOVA), showed that this process is viable due holes obtained with overall superior quality, when compared with the ones generated in conventional stamping processes. Holes produced by tools types I, II and III presented good results in the holes overall precision. Nevertheless, in general, the best results were seen using tools type I, with punch angle of 22.5° and, lubrication/cooling conditions using 75% Hislip concentration as cutting fluid (water emulsion).