Comprehensive Investigations of Cutting with Round Insert: Introduction of a Predictive Force Model with Verification

Judit Lukács,Richárd Horváth

doi:10.3390/met12020257

Abstract

The observation and prediction of cutting forces are key questions when planning manufacturing technologies. In this paper, all three force components are investigated in the case of turning with round insert. The specific cutting forces were used and adapted for the round insert. Two easily calculable parameters of the undeformed chip cross-section were introduced (heq—equivalent chip thickness and leff—total length of the engaged cutting edge). The dependency of the specific force components was examined with regards to heq and leff. The main goal was to generate new empirical force models for each component, which helps to estimate their values in a wide range of technological parameters from fine to rough machining. The application of the models was confirmed by a case study where 11SMn30 + C (1.0715) was investigated. The examined interval of cutting parameters was: for feed, f = 0.12… 0.6 mm, and for depth of cut, ap = 1.2… 4.8 mm. The novelty of the article is that the introduced new force models based on the geometric parameters characterizing the undeformed chip cross-section of round insert are proper for predicting the cutting force components in the technological process planning with an accuracy high enough—for main cutting force (Fc) −3.79%… +4.43%, for feed force component (Ff) −5.4%… +5.99%, and for radial force component (Fr) −4.49%… +4.77%.

Highlights

The quality requirements of cut parts are strongly influenced by the set cutting parameters, and by the generated forces.the investigation of cutting forces and the examination processes constitute an important field of research nowadays
In the case of turning with round insert, a significance test was carried out for each component in order to determine the influential parameters of the undeformed chip crosssection
The results showed that le f f has a non-significant effect on kc (in line with the Kienzle model [6,7], see Equation (5))

Summary

Introduction

The quality requirements of cut parts (e.g., geometrical accuracies, surface roughness parameters, etc.) are strongly influenced by the set cutting parameters, and by the generated forces (see Figure 1). The investigation of cutting forces and the examination processes constitute an important field of research nowadays. The cutting force and its spatial components are related to further important issues such as the geometric error of the finished workpiece, the energy consumption of the cutting operation, residual stress in the workpiece, adaptive control, and so forth. It was revealed that the residual stress was sourced from several parts, such as the action of the cutting force components, the temperature generated, and the phase transformation in the surface layer. The knowledge and the investigation of the cutting forces and their components is an important research field in cutting technologies.

Methods

Results

Conclusion