Papers by Keyword: Machine Center

Abstract: Globoidal Cam Indexing Mechanisms are used extensively as automatic tool changers (ATC) of machining centres or as indexing mechanisms in various machinery.By applying the theory of conjugate surface , the model for the surface design of the Globoidal Cam Indexing Mechanism of ATC is developed with MathCAD and Pro/E. The dynamic simulation of the me

Abstract: There is often more than one failure at the same time when NC machine tools fails, but only one failure data is recorded which leads to that the reliability model of NC machine tools is not rational. In addition, the assumption of “repaired as good as new” for NC machine tools which consists of hydraulic, mechanic and other complicated subsystems is questionable and unreasonable. In this paper a method of reliability modeling using Blocksim and Weibull++ for NC machine tools is proposed. In the end, one example is provided and examined to show its potential applications and benefits. The result shows that the method of reliability modeling is more scientific and more in line with the practice.

Abstract: In small and medium batch series manufacturing the small tool and workpiece changing time is one of the main objectives to follow in obtaining high productivity. These auxiliary times are defined as the times consumed with preparing and changing the next tool or workpiece to follow the machining process, times that usually overlap the machining process. For this purpose machining centres are equipped with an automatic tool changer system and an automatic pallet changer system. The palletizing systems imply eliminating the times consumed with the alignment, fixing and clamping of the workpieces, these systems consisting of several mechanisms: the pallet, the automatic pallet changing mechanism, the positioning mechanism and the pallet clamp/unclamp mechanism. In this paper we present an general overview of the automatic pallet changing mechanisms used both in flexible manufacturing systems and machining centres.

Abstract: This paper integrates machine center cutting process and magnetic abrasive finishing(MAF) producing a combined process that improves the magnetic abrasive loss rate(MALR) and roughness(Ra) of aluminum alloy 6061-T6 with ladder shape of different height. The present study shows the features of the development with mathematical model based on response surface methodology (RSM) for correlating the interactive and second order influences of major machining parameters such as different size and shape abrasive of stainless, spindle speed, tool and workpiece gap, feed speed, respectively. The experiments design, regression analysis and analysis of variance are used to develop the relationships between process parameters (abrasive size, spindle speed, tool and workpiece gap, feed speed) and responses (MALR and Ra) in MAF process. Sensitivity analysis has also been carried out using developed empirical equations. The results shows that developed mathematical models can be applied to estimate the effectiveness of process parameters for MALR and Ra with a change of spindle speed affects the MALR more strongly than Ra relatively compare to other parameters.

Abstract: Modal analysis of machine center was carried out by means of finite-element analysis (FEA) method to get its characteristics and to improve its machining precision. Based on this, harmonic response analysis was processed to evaluate its vibration when the cycle load caused by the machining force was applied on the main shaft of machine center, which was used to provide clues for avoiding resonance vibration and ameliorating design.

Abstract: Virtual numerical control milling simulation system, based on UG, is studied oriented to low utilization of NC machines. A virtual machine tools library, standard fixture library and visual machine tool processing environment were established by the second development techniques of UG and VC++. Through the example of XH715 NC machine center, tool path and motion of miller were simulated separately; at last processing scheme was evaluated and optimized. The experimental results show this system possesses good utility, and the utilization of machine tools could thus be improved.