Experimental Research on the Dynamic Stability of Internal Turning Tools for Long Overhangs

Abstract

The roughness origin of machined surfaces is caused by the following physical causes: the copying of the shape and the roughness of the cutting part of the tool into the workpiece, the existence of vibration of the tool, and the existence of the build-up edge (BUE) on the cutting edge. The current work aims to analyze the vibration amplitude of tools. The roughness of the machined surfaces was observed on hardened steel workpieces. Internal turning technology was used, and we used several different boring bars (steel; carbide; tuned mass damper—TMD; impact damper—ID) and an internal turning operation using CBN inserts. We revealed the tool’s slenderness coefficient (TSC) values for stable cutting operations. For the steel holder, the value is TSC ≤ 4.25; for the carbide holder, the value is TSC ≤ 5.5; for the TMD holder, the value is 4.5 ≤ TSC ≤ 7.75; and for the ID holder, the value is TSC ≤ 8. The surface’s roughness was practically unchanged within the limits of stable machining. However, if the tools exceed the presented stable limits, vibration and roughness parameters deteriorate significantly; an example parameter (Ra) deteriorated from 0.350 μm to 1.832 μm.

Experimental Evaluation of Flexible Fixture Stiffness for Steering Knuckles When Loading a Milling Machine Tool

“…They provide a rigid and stationary position of the workpiece during machining, which guarantees the accuracy of the dimensions and geometry of the finished part [10]. The correct design of the fixture determines the method of fixing the workpiece, the use of technological capabilities of the machine tool, the choice of cutting parameters [11], and the trajectory of the tool [12]. It significantly affects the setup time of mechanical operations [13].…”

Standalone Sensors System for Real-Time Monitoring of Cutting Emulsion Properties with Adaptive Integration in Machine Tool Operation

“…Sensors can provide real-time information about the machining process, such as temperature, vibration, and tool wear [1], as well as gather data about cutting fluids or cutting emulsions. Although modern machining methods tend towards dry machining [2,3] or machining with a minimum amount of cutting fluids [4], on the other side in conventional machining operations [5][6][7], cutting fluids play a critical role in reducing tool wear, improving the surface finish, and maintaining workpiece accuracy. However, the use of cutting fluids can lead to environmental and health issues, and sensor technology has been proposed as a means of reducing the negative impacts of cutting fluids' use.…”