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1

Monitoring of cutting conditions with the empirical mode decomposition

Wolszczak P., Łygas K., Litak G.

Advances in Science and Technology. Research Journal

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2017

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Vol. 11, no 1

96--103

EN

In this paper, we apply empirical mode decomposition by Huang and Hilbert to transform signals recorded during a milling process. Vibroacoustic sensors recorded vibrations of a tool-workpiece system while milling with the end mill of a special shape of “Hi-Feed”. The results of Huang-Hilbert analysis provide the information about amplitudes and frequencies of empirical modal components. Application of Huang-Hilbert transform to cutting conditions monitoring allows the separation of various vibration components caused by phenomena associated with the drive system and the machine components. Therefore, the analysis highlights vibrations caused by known sources of vibration, such as spindle speed, the number of teeth of the cutting tool or the frequency of vibration tools. Furthermore, signal components generated in the cutting zone were identified. The resulting information helps to assess the working conditions of cutting tools, selection of cutting parameters and tool wear monitoring.

2

Development on technique regarding change of resonance frequency on machine tool for optimization of cutting condition

Da Cruz J. R., Tanabe I., Inoue Y.

Journal of Machine Engineering

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2014

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Vol. 14, No. 3

35--47

EN

Establishment and selection of proper cutting condition can improve tool life and final cutting result. Cutting speed, feed speed, depth of cut and selection of tools are conditions of cutting that determined the cutting accuracy. However, when the optimum cutting condition with selected cutting speed coincides with machine resonance frequency, large vibration will occur. Consequently, even small periodic of driving forces can produce large amplitude vibrations. The simple technique to lower resonant frequency of machine tool was developed in previous research by using mixture of water and polymer with 6wt% concentration. As it was difficult to obtain damping ratio when the concentration is larger than 6wt%, therefore, the aim of this paper is to change machine resonant frequency for optimizing cutting condition by improving mixture concentration of water and polymer. It is concluded from the results that (1) By controlling machine tool resonance frequency enable cutting speed to be used for processing at its optimum cutting condition (2) New damping value of polymer mixed with water was presented, (3) Machine vibration reduced as resonance of machine was successfully avoided and surface roughness was also improved.

3

Cutting conditions from different data bases and tool flow in flexible manufacturing system

Cus F., Balic J.

Applied Mechanics and Engineering

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1999

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Vol. 4, no spec.

127-132

EN

The contribution presents the determination and selection of optimal conditions reducing the manufacturing costs. The data can be selected from different bases and are optimized with respect to boundary conditions of the own production. By taking into account the simultaneous engineering method it is necessary to carry out integrated and parallel activities of the detail design and production process. For building the tool data bank the "specialities" of the own production are taken into account. For the analysis of the tool and workpiece flow the principle of "virtual production" is considered. Accurate cost analyses are made for planning of the needs. In the processes of simultaneous optimization all requirements and the technology strategy are considered in order to meet the criteria of low costs and maximum quality. The researches and the results were tested in the real production environment.