Experimental Study of the Process of Boring Machine Parts Using a Cutter Equipped With Tensor Sensors

The article presents a methodology for experimental investigation of the boring process of non-rigid helical machine parts. Based on an analysis of recent research in this field, requirements are established for the physicomechanical properties of the workpiece material, technological and design parameters of helical parts, and their manufacturing technologies. Experimental results are described, particularly focusing on boring forces. During the machining of holes with small internal diameters in non-rigid helical workpieces made of materials that form continuous chips, friction between the chips and the machined surface and chip jamming inside the hole are observed. Accordingly, the quality of the machined surface depends on the chip curling behavior. A special boring tool setup with strain gauge sensors was developed for precise cutting force measurement. A tool with a replaceable cubic boron nitride (CBN) insert was used to create different internal profiles and to study the influence of tool geometry on the boring process. To ensure measurement accuracy, the strain gauges were calibrated on a custom test rig using lever systems in a static position. The experimental study established and optimized recommended feed values relative to specified surface roughness and cutting depth parameters. The research also revealed that cutting speed must be maintained within certain limits; otherwise, the helical surface may deform or bend. Resulting graphs demonstrated patterns of boring parameters: cutting forces decrease with increasing cutting speed, while forces increase with higher feed rate, cutting depth, and spiral thickness.