Recently, the demand to reduce the energy consumption of NC machine tools is increasing. In particular, revealing the energy consumption during cutting process is important, many studies have been accomplished. However, few studies have shown the relationship between the cutting force and energy consumption during cutting process. In this study, in order to clarify the relationship, measurement tests of the power consumption, motor toques and cutting forces are carried out during peripheral milling operations using square end mills. The tests are carried out with various material removal rate, down and up cuts, and different number of flutes. Losses of each part are evaluated based on the energy consumptions per one cubic millimeter material removal volume. As the results, it is confirmed that the energy consumption during the down cut milling is smaller than it during the up cut milling. It is also confirmed that the higher number of flute reduces the energy consumption.

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A new machining method of curved hole by EDM using a suspended metal ball electrode with a lead wire from the head of ED machine is newly proposed in this study. The EDM characteristics, such as removal volume and machined hole diameter were compared using CuW ball electrodes of 5.5mm in diameter suspended with thin wire, foil, and chain, in order to optimize the suspending part structure and the machining conditions. Experimental results showed that the removal rate using the suspended electrode with the chain was higher than that using a rod electrode under the optimum conditions. It was also clarified that the servo voltage and discharge current were dominant parameters to keep a stable machining performance. Moreover, bending holes with various bending angles and complicated curve holes were created, and the high possibility of this method was shown.

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The aim of this study is to investigate the cutting phenomenon under Ultrasonically Assisted Cutting (UAC) condition. The vibrating cutting edge is considered to be cause of dynamic change of cutting force at ultrasonic frequency. However many researchers have explained the effect of UAC by evaluating the time-averaged cutting force, because it is difficult to measure the dynamic cutting force by using dynamometers. In this study, the instantaneous stress distribution on workpiece was visualized by photoelastic method in combination of pulse light emission synchronized with vibration of cutting edge. Applying a uniaxial compression test, the fringe map relative to phase-difference defined by Brewster's law was calibrated with stress distribution. Orthogonal cutting test was carried out at low cutting speed relative to vibration speed of insert. The cutting force calculated from stress distribution was considerably agreed with measured force by dynamometer. It was experimentally confirmed that the stress distribution under UAC condition showed the periodical change synchronized with insert vibration. The instantaneous maximum cutting force under UAC condition was smaller than that of conventional cutting condition. The geometrical analysis of cutting force explained the greater shear angle by decrease of friction angle under UVC condition.

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Forming the cutting edge of stainless steel cutlery is generally carried out by grinding wheel and polishing with leather strop. Nanometer-level shape controllability of the edge in the polishing process is strongly required for better cutting performance. In order to achieve stably high shape accuracy of cutting edge, high technical skill has been needed, considering the wear of lather strop and the changes in environmental conditions, such as temperature and humidity. In this study, deburring and shape control of cutting edge by ion beam machining were experimentally investigated as an alternative to the conventional leather strop polishing. Experimental results clarified that ion beam irradiation from the front to the edge made the edge shape dull, while that from the side made it sharp. By continuously changing the direction of ion beam irradiation to the edge, the burr was perfectly removed and the edge radius in several nm was successfully obtained. Furthermore, the cutting performance was highly improved by plasma nitriding after the edge finishing with the multi-directional ion beam irradiation, compared with that of conventionally finished one with leather strop.

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Cutting force can be reduced by using surface micro-textured tools even under dry conditions. In the previous research, it was found that the surface textures for reduction in cutting force must have concave portions intermittently at the contact region far away from the cutting edge. This result supposes that textures bring about a reduction in adhesive force acting at the interface and reduce cutting force. In order to investigate an effect of surface textures on reduction in adhesive force, dry friction tests with the loading and unloading process were carried out. The results indicated that the surface textures can reduce the adhesive force. Moreover, a cutting model established by the slip-line field method was proposed in order to consider the effect of adhesive force on the deformation field state including shear angle, chip curl radius and tool-chip contact length which strongly affects cutting force. The change in the deformation field state following the reduction in the adhesive force corresponds to the experimental results with the textured tools. From the results, it was suggested that the mechanisms of reduction in cutting force attached under dry conditions can be well described by considering the existence of adhesive restriction between tool and chip.

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The Fourier transform method is a method of analysis to extract a phase from a fringe pattern. However, when noise and shape components overlap each other in the Fourier domain, it is difficult to eliminate only the overlapped noise components using conventional filtering techniques, such as bandpass filtering. In this paper, to solve this problem of the filter, the two-step Fourier transform method is proposed by using two interferograms with slightly different carrier frequencies. The proposed method has been applied to the grating projection method using gratings with different colors according to the carrier frequency and the validity of the proposed method was investigated.

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Microbend-induced long period fiber gratings (M-LPFG) are loss- and wavelength-tunable and can be reconfigured as compared to laser-irradiated types. However, they are inherently polarization sensitive due to stress-induced birefringence and coupling nature with asymmetric cladding modes. By analyzing the state of polarization along the M-LPFG, the rotation efficiency of the polarization principal axis due to the torsional fiber is changed by the vertical stress, and the polarization ellipticity is changed simultaneously. The polarization dependency can be sufficiently reduced by twisting the fiber for inducing the microbend. In the experiments, the loss amplitude at the resonance wavelength is controlled by the combination of a coil spring and a neodymium magnet.

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The objective of this study is to develop an automatic process planning system in a complex machining, specifically for a turning-milling center with 2 turrets system. The machining feature recognition is carried out based on delta volume decomposition and surface identification. The system is able to recognize the machining features with any type of surfaces such as planar, inclined planar, cylindrical, spherical, conical, and toroid. The SolidWorks API was used in the designed system for delta volume extraction; disassembly of the delta volume into simple machining features, surface's parameter identification, machining feature recognition, sequence determination, and prediction of processing time. Furthermore, the process planning system is able to generate all possible machining solutions, evaluate the machining plan and choose the appropriate machining plan based on the user's evaluation criteria. At this stage, the developed system is able to select the best machining process plan, based on shortest processing time. Finally, this paper proposes a new process planning method for turning-milling machining center with 2-turrets system, and presents the result of process planning simulation.

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