Browsing by Author "Deng, CS"

Now showing 1 - 3 of 3

Effects of support misalignments in deep-hole drill shafts on hole straightness
(2001-06-01)
Deng, CS
;
Huang, JC
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
This work investigates the effect of drill shaft support misalignment on hole straightness in relation to the various control factors. Misalignments occur in machine spindles, intermediate supports and pilot bushings. Equations for axial hole straightness deviation are derived herein using the Euler column theory, and experiments are performed using Gundrill and BTA deep-hole drilling systems. Simulation results, Sakuma's method and experimental examinations are also presented. Taguchi methods and statistical techniques are used to formulate the experimental layout, analyze the effect of each control factor on the results, and optimize the setting for each control factor. Further experiments then verify these estimates. Six control factors were used in a modified L8 orthogonal array design. The confirmatory experiments revealed an average straightness deviation within the 95% confidence interval. (C) 2001 Published by Elsevier Science Ltd.
Hole roundness in deep-hole drilling as analysed by Taguchi methods
(2005)
Deng, CS
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
This work investigates the roundness of holes by application of Taguchi methods to BTA deep-hole drilling with reference to process factors. Taguchi methods and statistical techniques are used in experimental layout, in the analysis of each control factor, and in prediction of the optimum setting for control factors. A set of confirmatory tests is then conducted to verify the estimated response. Influences of the control factors are discussed, and the levels of factors that produce holes of desired roundness with sufficient robustness are presented.
Roundness, errors in BTA drilling and a model of waviness and lobing caused by resonant forced vibrations of its long drill shaft
(2004-08-01)
Deng, CS
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
The original purpose of this work was to propose an equation system to describe the kind of drilling in which the tools are with pronounced shaft length. The equation system turned out to disclose the low frequency mechanism of hole lobes. The proposed system is composed of Euler-Bernoulli beam equation representing tool shaft, and an excitation force in form of Fourier series. An empirical cutting force was established and related cutting force components were calculated. And the accumulated contribution of modes and harmonics was evaluated. The solution for the proposed equation system allowed a prediction of hole roundness which was consistent with experimental results for different conditions. The solution also allowed an investigation into the waviness and lobes. The results suggested that the bizarre phenomenon of lobes on hole is in reality waviness described by Tlusty for milling. The rigorous mathematical nature of the proposed equation built solid foundation for former empirical observation of waviness and lobes on workpieces.