Circular tests for HSM machine tools: Bore machining application

Abstract

Today's High-Speed Machining (HSM) machine tool combines productivity and part quality. The difficulty inherent in HSM operations lies in understanding the impact of machine tool behaviour on machining time and part quality. Analysis of some of the relevant ISO standards (230-1998, 10791-1998) and a complementary protocol for better understanding HSM technology are presented in the first part of this paper. These ISO standards are devoted to the procedures implemented in order to study the behavior of machine tool. As these procedures do not integrate HSM technology, the need for HSM machine tool tests becomes critical to improving the trade-off between machining time and part quality. A new protocol for analysing the HSM technology impact during circular interpolation is presented in the second part of the paper. This protocol which allows evaluating kinematic machine tool behaviour during circular interpolation was designed from tests without machining. These tests are discussed and their results analysed in the paper. During the circular interpolation, axis capacities (such as acceleration or Jerk) related to certain setting parameters of the numerical control unit have a significant impact on the value of the feed rate. Consequently, a kinematic model for a circular-interpolated trajectory was developed on the basis of these parameters. Moreover, the link between part accuracy and kinematic machine tool behaviour was established. The kinematic model was ultimately validated on a bore machining simulation

Modeling and simulation of high-speed milling centers dynamics

“…Tapis et al [14] add the effects of the tangential jerk in curvature J tcurv and prove its limitation effect by the experimental. The tangential jerk in curvature is the product of the curvilinear tangential jerk J curv and of the rate of the curvilinear jerk associated to the tangential jerk r jct .…”

“…If the feed rate is constant, the corresponding acceleration is only normal A n [14]. Then, so as the machine can follow a curve of a curvature radius R, at an imposed feed rate V f , we must necessarily have:…”

Optimization of pocket machining strategy in HSM

“…The considerable constraints are due to the behavior of the numerical control unit (NCU) [9,10]. The detailed behavior of the NCU is in accordance with the real behavior in HSM.…”

“…Monreal and Rodriguez [5], Tournier et al [13], and Tapie et al [9,10] have worked on the adaptation of the tool path to the HSM machine cinematics. Pateloup et al [7,8] and Mawussi et al [3] have structured a methodology to help choose the machining strategy for such a pocket geometry in a context of high-speed machining.…”

“…Tapie et al [9,10] and Pateloup et al [7] have integrated the dynamic modelization in order to determine the causes of the variations applied to the feed rate. This modelization integrates the jerk, the acceleration, and the interpolation cycle time so as to explicit the slowing down of the machine in linear and circular interpolation.…”